Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
"This update provides the following changes:

- The rework of the timer wheel which addresses the shortcomings of
the current wheel (cascading, slow search for next expiring timer,
etc). That's the first major change of the wheel in almost 20
years since Finn implemted it.

- A large overhaul of the clocksource drivers init functions to
consolidate the Device Tree initialization

- Some more Y2038 updates

- A capability fix for timerfd

- Yet another clock chip driver

- The usual pile of updates, comment improvements all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (130 commits)
tick/nohz: Optimize nohz idle enter
clockevents: Make clockevents_subsys static
clocksource/drivers/time-armada-370-xp: Fix return value check
timers: Implement optimization for same expiry time in mod_timer()
timers: Split out index calculation
timers: Only wake softirq if necessary
timers: Forward the wheel clock whenever possible
timers/nohz: Remove pointless tick_nohz_kick_tick() function
timers: Optimize collect_expired_timers() for NOHZ
timers: Move __run_timers() function
timers: Remove set_timer_slack() leftovers
timers: Switch to a non-cascading wheel
timers: Reduce the CPU index space to 256k
timers: Give a few structs and members proper names
hlist: Add hlist_is_singular_node() helper
signals: Use hrtimer for sigtimedwait()
timers: Remove the deprecated mod_timer_pinned() API
timers, net/ipv4/inet: Initialize connection request timers as pinned
timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned
timers, drivers/tty/metag_da: Initialize the poll timer as pinned
...

Documentation/devicetree/bindings/timer/oxsemi,rps-timer.txt

···
+Oxford Semiconductor OXNAS SoCs Family RPS Timer
+================================================
+
+Required properties:
+- compatible: Should be "oxsemi,ox810se-rps-timer"
+- reg : Specifies base physical address and size of the registers.
+- interrupts : The interrupts of the two timers
+- clocks : The phandle of the timer clock source
+
+example:
+
+timer0: timer@200 {
+	compatible = "oxsemi,ox810se-rps-timer";
+	reg = <0x200 0x40>;
+	clocks = <&rpsclk>;
+	interrupts = <4 5>;
+};

Documentation/devicetree/bindings/timer/rockchip,rk3288-timer.txt Documentation/devicetree/bindings/timer/rockchip,rk-timer.txt

···
-Rockchip rk3288 timer
+Rockchip rk timer
 
 Required properties:
-- compatible: shall be "rockchip,rk3288-timer"
+- compatible: shall be one of:
+  "rockchip,rk3288-timer" - for rk3066, rk3036, rk3188, rk322x, rk3288, rk3368
+  "rockchip,rk3399-timer" - for rk3399
 - reg: base address of the timer register starting with TIMERS CONTROL register
 - interrupts: should contain the interrupts for Timer0
 - clocks : must contain an entry for each entry in clock-names

Documentation/kernel-parameters.txt

···
 			[SPARC64] tick
 			[X86-64] hpet,tsc
 
+	clocksource.arm_arch_timer.evtstrm=
+			[ARM,ARM64]
+			Format: <bool>
+			Enable/disable the eventstream feature of the ARM
+			architected timer so that code using WFE-based polling
+			loops can be debugged more effectively on production
+			systems.
+
 	clearcpuid=BITNUM [X86]
 			Disable CPUID feature X for the kernel. See
 			arch/x86/include/asm/cpufeatures.h for the valid bit

arch/arc/kernel/time.c

···
 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void __init arc_cs_setup_gfrc(struct device_node *node)
+static int __init arc_cs_setup_gfrc(struct device_node *node)
 {
 	int exists = cpuinfo_arc700[0].extn.gfrc;
 	int ret;
 
 	if (WARN(!exists, "Global-64-bit-Ctr clocksource not detected"))
-		return;
+		return -ENXIO;
 
 	ret = arc_get_timer_clk(node);
 	if (ret)
-		return;
+		return ret;
 
-	clocksource_register_hz(&arc_counter_gfrc, arc_timer_freq);
+	return clocksource_register_hz(&arc_counter_gfrc, arc_timer_freq);
 }
 CLOCKSOURCE_OF_DECLARE(arc_gfrc, "snps,archs-timer-gfrc", arc_cs_setup_gfrc);
 
···
 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void __init arc_cs_setup_rtc(struct device_node *node)
+static int __init arc_cs_setup_rtc(struct device_node *node)
 {
 	int exists = cpuinfo_arc700[smp_processor_id()].extn.rtc;
 	int ret;
 
 	if (WARN(!exists, "Local-64-bit-Ctr clocksource not detected"))
-		return;
+		return -ENXIO;
 
 	/* Local to CPU hence not usable in SMP */
 	if (WARN(IS_ENABLED(CONFIG_SMP), "Local-64-bit-Ctr not usable in SMP"))
-		return;
+		return -EINVAL;
 
 	ret = arc_get_timer_clk(node);
 	if (ret)
-		return;
+		return ret;
 
 	write_aux_reg(AUX_RTC_CTRL, 1);
 
-	clocksource_register_hz(&arc_counter_rtc, arc_timer_freq);
+	return clocksource_register_hz(&arc_counter_rtc, arc_timer_freq);
 }
 CLOCKSOURCE_OF_DECLARE(arc_rtc, "snps,archs-timer-rtc", arc_cs_setup_rtc);
 
···
 	.flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void __init arc_cs_setup_timer1(struct device_node *node)
+static int __init arc_cs_setup_timer1(struct device_node *node)
 {
 	int ret;
 
 	/* Local to CPU hence not usable in SMP */
 	if (IS_ENABLED(CONFIG_SMP))
-		return;
+		return -EINVAL;
 
 	ret = arc_get_timer_clk(node);
 	if (ret)
-		return;
+		return ret;
 
 	write_aux_reg(ARC_REG_TIMER1_LIMIT, ARC_TIMER_MAX);
 	write_aux_reg(ARC_REG_TIMER1_CNT, 0);
 	write_aux_reg(ARC_REG_TIMER1_CTRL, TIMER_CTRL_NH);
 
-	clocksource_register_hz(&arc_counter_timer1, arc_timer_freq);
+	return clocksource_register_hz(&arc_counter_timer1, arc_timer_freq);
 }
 
 /********** Clock Event Device *********/
···
 /*
  * clockevent setup for boot CPU
  */
-static void __init arc_clockevent_setup(struct device_node *node)
+static int __init arc_clockevent_setup(struct device_node *node)
 {
 	struct clock_event_device *evt = this_cpu_ptr(&arc_clockevent_device);
 	int ret;
 
-	register_cpu_notifier(&arc_timer_cpu_nb);
+	ret = register_cpu_notifier(&arc_timer_cpu_nb);
+	if (ret) {
+		pr_err("Failed to register cpu notifier");
+		return ret;
+	}
 
 	arc_timer_irq = irq_of_parse_and_map(node, 0);
-	if (arc_timer_irq <= 0)
-		panic("clockevent: missing irq");
+	if (arc_timer_irq <= 0) {
+		pr_err("clockevent: missing irq");
+		return -EINVAL;
+	}
 
 	ret = arc_get_timer_clk(node);
-	if (ret)
-		panic("clockevent: missing clk");
+	if (ret) {
+		pr_err("clockevent: missing clk");
+		return ret;
+	}
 
 	evt->irq = arc_timer_irq;
 	evt->cpumask = cpumask_of(smp_processor_id());
···
 	/* Needs apriori irq_set_percpu_devid() done in intc map function */
 	ret = request_percpu_irq(arc_timer_irq, timer_irq_handler,
 				 "Timer0 (per-cpu-tick)", evt);
-	if (ret)
-		panic("clockevent: unable to request irq\n");
+	if (ret) {
+		pr_err("clockevent: unable to request irq\n");
+		return ret;
+	}
 
 	enable_percpu_irq(arc_timer_irq, 0);
+
+	return 0;
 }
 
-static void __init arc_of_timer_init(struct device_node *np)
+static int __init arc_of_timer_init(struct device_node *np)
 {
 	static int init_count = 0;
+	int ret;
 
 	if (!init_count) {
 		init_count = 1;
-		arc_clockevent_setup(np);
+		ret = arc_clockevent_setup(np);
 	} else {
-		arc_cs_setup_timer1(np);
+		ret = arc_cs_setup_timer1(np);
 	}
+
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(arc_clkevt, "snps,arc-timer", arc_of_timer_init);
 

arch/arm/Kconfig

···
 	bool "Cirrus Logic CLPS711x/EP721x/EP731x-based"
 	select ARCH_REQUIRE_GPIOLIB
 	select AUTO_ZRELADDR
-	select CLKSRC_MMIO
 	select COMMON_CLK
 	select CPU_ARM720T
 	select GENERIC_CLOCKEVENTS
+	select CLPS711X_TIMER
 	select MFD_SYSCON
 	select SOC_BUS
 	help

arch/arm/kernel/smp_twd.c

···
 }
 
 #ifdef CONFIG_OF
-static void __init twd_local_timer_of_register(struct device_node *np)
+static int __init twd_local_timer_of_register(struct device_node *np)
 {
 	int err;
 
···
 
 out:
 	WARN(err, "twd_local_timer_of_register failed (%d)\n", err);
+	return err;
 }
 CLOCKSOURCE_OF_DECLARE(arm_twd_a9, "arm,cortex-a9-twd-timer", twd_local_timer_of_register);
 CLOCKSOURCE_OF_DECLARE(arm_twd_a5, "arm,cortex-a5-twd-timer", twd_local_timer_of_register);

arch/arm/mach-bcm/Kconfig

···
 	select HAVE_ARM_ARCH_TIMER
 	select PINCTRL
 	select ARCH_BCM_MOBILE_SMP if SMP
+	select BCM_KONA_TIMER
 	help
 	  This enables support for systems based on Broadcom mobile SoCs.
 
···
 	select ARM_TIMER_SP804
 	select HAVE_ARM_ARCH_TIMER if ARCH_MULTI_V7
 	select CLKSRC_OF
+	select BCM2835_TIMER
 	select PINCTRL
 	select PINCTRL_BCM2835
 	help

arch/arm/mach-integrator/Kconfig

···
 
 config ARCH_INTEGRATOR_AP
 	bool "Support Integrator/AP and Integrator/PP2 platforms"
-	select CLKSRC_MMIO
+	select INTEGRATOR_AP_TIMER
 	select MIGHT_HAVE_PCI
 	select SERIAL_AMBA_PL010 if TTY
 	select SERIAL_AMBA_PL010_CONSOLE if TTY

arch/arm/mach-keystone/Kconfig

···
 	depends on ARM_PATCH_PHYS_VIRT
 	select ARM_GIC
 	select HAVE_ARM_ARCH_TIMER
-	select CLKSRC_MMIO
+	select KEYSTONE_TIMER
 	select ARM_ERRATA_798181 if SMP
 	select COMMON_CLK_KEYSTONE
 	select ARCH_SUPPORTS_BIG_ENDIAN

arch/arm/mach-moxart/Kconfig

···
 	depends on ARCH_MULTI_V4
 	select CPU_FA526
 	select ARM_DMA_MEM_BUFFERABLE
-	select CLKSRC_MMIO
+	select MOXART_TIMER
 	select GENERIC_IRQ_CHIP
 	select ARCH_REQUIRE_GPIOLIB
 	select PHYLIB if NETDEVICES

arch/arm/mach-mxs/Kconfig

···
 	bool "Freescale MXS (i.MX23, i.MX28) support"
 	depends on ARCH_MULTI_V5
 	select ARCH_REQUIRE_GPIOLIB
-	select CLKSRC_MMIO
+	select MXS_TIMER
 	select PINCTRL
 	select SOC_BUS
 	select SOC_IMX23

arch/arm/mach-nspire/Kconfig

···
 	select ARM_AMBA
 	select ARM_VIC
 	select ARM_TIMER_SP804
+	select NSPIRE_TIMER
 	help
 	  This enables support for systems using the TI-NSPIRE CPU

arch/arm/mach-prima2/Kconfig

···
 	default y
 	select ARM_GIC
 	select CPU_V7
+	select ATLAS7_TIMER
 	select HAVE_ARM_SCU if SMP
 	select HAVE_SMP
 	help
···
 	default y
 	select SIRF_IRQ
 	select ZONE_DMA
+	select PRIMA2_TIMER
 	help
           Support for CSR SiRFSoC ARM Cortex A9 Platform
 

arch/arm/mach-u300/Kconfig

···
 	select ARCH_REQUIRE_GPIOLIB
 	select ARM_AMBA
 	select ARM_VIC
-	select CLKSRC_MMIO
+	select U300_TIMER
 	select CPU_ARM926T
 	select HAVE_TCM
 	select PINCTRL

arch/arm64/boot/dts/rockchip/rk3399.dtsi

···
 		interrupts = <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
+	rktimer: rktimer@ff850000 {
+		compatible = "rockchip,rk3399-timer";
+		reg = <0x0 0xff850000 0x0 0x1000>;
+		interrupts = <GIC_SPI 81 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&cru PCLK_TIMER0>, <&cru SCLK_TIMER00>;
+		clock-names = "pclk", "timer";
+	};
+
 	spdif: spdif@ff870000 {
 		compatible = "rockchip,rk3399-spdif";
 		reg = <0x0 0xff870000 0x0 0x1000>;

arch/microblaze/kernel/timer.c

···
 	.dev_id = &clockevent_xilinx_timer,
 };
 
-static __init void xilinx_clockevent_init(void)
+static __init int xilinx_clockevent_init(void)
 {
 	clockevent_xilinx_timer.mult =
 		div_sc(timer_clock_freq, NSEC_PER_SEC,
···
 		clockevent_delta2ns(1, &clockevent_xilinx_timer);
 	clockevent_xilinx_timer.cpumask = cpumask_of(0);
 	clockevents_register_device(&clockevent_xilinx_timer);
+
+	return 0;
 }
 
 static u64 xilinx_clock_read(void)
···
 
 static int __init xilinx_clocksource_init(void)
 {
-	if (clocksource_register_hz(&clocksource_microblaze, timer_clock_freq))
-		panic("failed to register clocksource");
+	int ret;
+
+	ret = clocksource_register_hz(&clocksource_microblaze,
+				      timer_clock_freq);
+	if (ret) {
+		pr_err("failed to register clocksource");
+		return ret;
+	}
 
 	/* stop timer1 */
 	write_fn(read_fn(timer_baseaddr + TCSR1) & ~TCSR_ENT,
···
 	write_fn(TCSR_TINT|TCSR_ENT|TCSR_ARHT, timer_baseaddr + TCSR1);
 
 	/* register timecounter - for ftrace support */
-	init_xilinx_timecounter();
-	return 0;
+	return init_xilinx_timecounter();
 }
 
-static void __init xilinx_timer_init(struct device_node *timer)
+static int __init xilinx_timer_init(struct device_node *timer)
 {
 	struct clk *clk;
 	static int initialized;
 	u32 irq;
 	u32 timer_num = 1;
+	int ret;
 
 	if (initialized)
 		return;
···
 	timer_baseaddr = of_iomap(timer, 0);
 	if (!timer_baseaddr) {
 		pr_err("ERROR: invalid timer base address\n");
-		BUG();
+		return -ENXIO;
 	}
 
 	write_fn = timer_write32;
···
 	}
 
 	irq = irq_of_parse_and_map(timer, 0);
+	if (irq <= 0) {
+		pr_err("Failed to parse and map irq");
+		return -EINVAL;
+	}
 
 	of_property_read_u32(timer, "xlnx,one-timer-only", &timer_num);
 	if (timer_num) {
-		pr_emerg("Please enable two timers in HW\n");
-		BUG();
+		pr_err("Please enable two timers in HW\n");
+		return -EINVAL;
 	}
 
 	pr_info("%s: irq=%d\n", timer->full_name, irq);
···
 
 	freq_div_hz = timer_clock_freq / HZ;
 
-	setup_irq(irq, &timer_irqaction);
+	ret = setup_irq(irq, &timer_irqaction);
+	if (ret) {
+		pr_err("Failed to setup IRQ");
+		return ret;
+	}
+
 #ifdef CONFIG_HEART_BEAT
 	microblaze_setup_heartbeat();
 #endif
-	xilinx_clocksource_init();
-	xilinx_clockevent_init();
+
+	ret = xilinx_clocksource_init();
+	if (ret)
+		return ret;
+
+	ret = xilinx_clockevent_init();
+	if (ret)
+		return ret;
 
 	sched_clock_register(xilinx_clock_read, 32, timer_clock_freq);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(xilinx_timer, "xlnx,xps-timer-1.00.a",

arch/mips/ralink/cevt-rt3352.c

···
 	return 0;
 }
 
-static void __init ralink_systick_init(struct device_node *np)
+static int __init ralink_systick_init(struct device_node *np)
 {
+	int ret;
+
 	systick.membase = of_iomap(np, 0);
 	if (!systick.membase)
-		return;
+		return -ENXIO;
 
 	systick_irqaction.name = np->name;
 	systick.dev.name = np->name;
···
 	systick.dev.irq = irq_of_parse_and_map(np, 0);
 	if (!systick.dev.irq) {
 		pr_err("%s: request_irq failed", np->name);
-		return;
+		return -EINVAL;
 	}
 
-	clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
-			SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
+	ret = clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
+				    SYSTICK_FREQ, 301, 16,
+				    clocksource_mmio_readl_up);
+	if (ret)
+		return ret;
 
 	clockevents_register_device(&systick.dev);
 
 	pr_info("%s: running - mult: %d, shift: %d\n",
 			np->name, systick.dev.mult, systick.dev.shift);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);

arch/nios2/kernel/time.c

···
 	return IRQ_HANDLED;
 }
 
-static void __init nios2_timer_get_base_and_freq(struct device_node *np,
+static int __init nios2_timer_get_base_and_freq(struct device_node *np,
 				void __iomem **base, u32 *freq)
 {
 	*base = of_iomap(np, 0);
-	if (!*base)
-		panic("Unable to map reg for %s\n", np->name);
+	if (!*base) {
+		pr_crit("Unable to map reg for %s\n", np->name);
+		return -ENXIO;
+	}
 
-	if (of_property_read_u32(np, "clock-frequency", freq))
-		panic("Unable to get %s clock frequency\n", np->name);
+	if (of_property_read_u32(np, "clock-frequency", freq)) {
+		pr_crit("Unable to get %s clock frequency\n", np->name);
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 static struct nios2_clockevent_dev nios2_ce = {
···
 	},
 };
 
-static __init void nios2_clockevent_init(struct device_node *timer)
+static __init int nios2_clockevent_init(struct device_node *timer)
 {
 	void __iomem *iobase;
 	u32 freq;
-	int irq;
+	int irq, ret;
 
-	nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+	ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+	if (ret)
+		return ret;
 
 	irq = irq_of_parse_and_map(timer, 0);
-	if (!irq)
-		panic("Unable to parse timer irq\n");
+	if (!irq) {
+		pr_crit("Unable to parse timer irq\n");
+		return -EINVAL;
+	}
 
 	nios2_ce.timer.base = iobase;
 	nios2_ce.timer.freq = freq;
···
 	/* clear pending interrupt */
 	timer_writew(&nios2_ce.timer, 0, ALTERA_TIMER_STATUS_REG);
 
-	if (request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
-		&nios2_ce.ced))
-		panic("Unable to setup timer irq\n");
+	ret = request_irq(irq, timer_interrupt, IRQF_TIMER, timer->name,
+			  &nios2_ce.ced);
+	if (ret) {
+		pr_crit("Unable to setup timer irq\n");
+		return ret;
+	}
 
 	clockevents_config_and_register(&nios2_ce.ced, freq, 1, ULONG_MAX);
+
+	return 0;
 }
 
-static __init void nios2_clocksource_init(struct device_node *timer)
+static __init int nios2_clocksource_init(struct device_node *timer)
 {
 	unsigned int ctrl;
 	void __iomem *iobase;
 	u32 freq;
+	int ret;
 
-	nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+	ret = nios2_timer_get_base_and_freq(timer, &iobase, &freq);
+	if (ret)
+		return ret;
 
 	nios2_cs.timer.base = iobase;
 	nios2_cs.timer.freq = freq;
 
-	clocksource_register_hz(&nios2_cs.cs, freq);
+	ret = clocksource_register_hz(&nios2_cs.cs, freq);
+	if (ret)
+		return ret;
 
 	timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODL_REG);
 	timer_writew(&nios2_cs.timer, USHRT_MAX, ALTERA_TIMER_PERIODH_REG);
···
 
 	/* Calibrate the delay loop directly */
 	lpj_fine = freq / HZ;
+
+	return 0;
 }
 
 /*
···
  * more instances, the second one gets used as clocksource and all
  * others are unused.
 */
-static void __init nios2_time_init(struct device_node *timer)
+static int __init nios2_time_init(struct device_node *timer)
 {
 	static int num_called;
+	int ret;
 
 	switch (num_called) {
 	case 0:
-		nios2_clockevent_init(timer);
+		ret = nios2_clockevent_init(timer);
 		break;
 	case 1:
-		nios2_clocksource_init(timer);
+		ret = nios2_clocksource_init(timer);
 		break;
 	default:
 		break;
 	}
 
 	num_called++;
+
+	return ret;
 }
 
 void read_persistent_clock(struct timespec *ts)

arch/x86/kernel/apic/x2apic_uv_x.c

···
 	uv_set_scir_bits(bits);
 
 	/* enable next timer period */
-	mod_timer_pinned(timer, jiffies + SCIR_CPU_HB_INTERVAL);
+	mod_timer(timer, jiffies + SCIR_CPU_HB_INTERVAL);
 }
 
 static void uv_heartbeat_enable(int cpu)
···
 		struct timer_list *timer = &uv_cpu_scir_info(cpu)->timer;
 
 		uv_set_cpu_scir_bits(cpu, SCIR_CPU_HEARTBEAT|SCIR_CPU_ACTIVITY);
-		setup_timer(timer, uv_heartbeat, cpu);
+		setup_pinned_timer(timer, uv_heartbeat, cpu);
 		timer->expires = jiffies + SCIR_CPU_HB_INTERVAL;
 		add_timer_on(timer, cpu);
 		uv_cpu_scir_info(cpu)->enabled = 1;

arch/x86/kernel/cpu/mcheck/mce.c

···
 
 	if (timer_pending(t)) {
 		if (time_before(when, t->expires))
-			mod_timer_pinned(t, when);
+			mod_timer(t, when);
 	} else {
 		t->expires = round_jiffies(when);
 		add_timer_on(t, smp_processor_id());
···
 	struct timer_list *t = this_cpu_ptr(&mce_timer);
 	unsigned int cpu = smp_processor_id();
 
-	setup_timer(t, mce_timer_fn, cpu);
+	setup_pinned_timer(t, mce_timer_fn, cpu);
 	mce_start_timer(cpu, t);
 }
 

block/genhd.c

···
 	if (--ev->block)
 		goto out_unlock;
 
-	/*
-	 * Not exactly a latency critical operation, set poll timer
-	 * slack to 25% and kick event check.
-	 */
 	intv = disk_events_poll_jiffies(disk);
-	set_timer_slack(&ev->dwork.timer, intv / 4);
 	if (check_now)
 		queue_delayed_work(system_freezable_power_efficient_wq,
 				&ev->dwork, 0);

drivers/clocksource/Kconfig

···
 config CLKSRC_MMIO
 	bool
 
+config BCM2835_TIMER
+	bool "BCM2835 timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables the support for the BCM2835 timer driver.
+
+config BCM_KONA_TIMER
+	bool "BCM mobile timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables the support for the BCM Kona mobile timer driver.
+
 config DIGICOLOR_TIMER
 	bool "Digicolor timer driver" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
···
 	help
 	  Use the always on PRCMU Timer as clocksource
 
+config CLPS711X_TIMER
+	bool "Cirrus logic timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Cirrus Logic PS711 timer.
+
+config ATLAS7_TIMER
+	bool "Atlas7 timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Atlas7 timer.
+
+config MOXART_TIMER
+	bool "Moxart timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Moxart timer.
+
+config MXS_TIMER
+	bool "Mxs timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	select STMP_DEVICE
+	help
+	  Enables support for the Mxs timer.
+
+config PRIMA2_TIMER
+	bool "Prima2 timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Prima2 timer.
+
+config U300_TIMER
+	bool "U300 timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	depends on ARM
+	select CLKSRC_MMIO
+	help
+	  Enables support for the U300 timer.
+
+config NSPIRE_TIMER
+	bool "NSpire timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Nspire timer.
+
+config KEYSTONE_TIMER
+	bool "Keystone timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	depends on ARM || ARM64
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Keystone timer.
+
+config INTEGRATOR_AP_TIMER
+	bool "Integrator-ap timer driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_MMIO
+	help
+	  Enables support for the Integrator-ap timer.
+
 config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
 	bool "Clocksource PRCMU Timer sched_clock"
 	depends on (CLKSRC_DBX500_PRCMU && !CLKSRC_NOMADIK_MTU_SCHED_CLOCK)
···
 	select CLKSRC_ACPI if ACPI
 
 config ARM_ARCH_TIMER_EVTSTREAM
-	bool "Support for ARM architected timer event stream generation"
+	bool "Enable ARM architected timer event stream generation by default"
 	default y if ARM_ARCH_TIMER
 	depends on ARM_ARCH_TIMER
 	help
-	  This option enables support for event stream generation based on
-	  the ARM architected timer. It is used for waking up CPUs executing
-	  the wfe instruction at a frequency represented as a power-of-2
-	  divisor of the clock rate.
+	  This option enables support by default for event stream generation
+	  based on the ARM architected timer. It is used for waking up CPUs
+	  executing the wfe instruction at a frequency represented as a
+	  power-of-2 divisor of the clock rate. The behaviour can also be
+	  overridden on the command line using the
+	  clocksource.arm_arch_timer.evtstream parameter.
 	  The main use of the event stream is wfe-based timeouts of userspace
 	  locking implementations. It might also be useful for imposing timeout
 	  on wfe to safeguard against any programming errors in case an expected
···
 	  hardware anomalies of missing events.
 
 config ARM_GLOBAL_TIMER
-	bool
+	bool "Support for the ARM global timer" if COMPILE_TEST
 	select CLKSRC_OF if OF
+	depends on ARM
 	help
 	  This options enables support for the ARM global timer unit
 
···
 	 Use ARM global timer clock source as sched_clock
 
 config ARMV7M_SYSTICK
-	bool
+	bool "Support for the ARMv7M system time" if COMPILE_TEST
 	select CLKSRC_OF if OF
 	select CLKSRC_MMIO
 	help
···
 	def_bool SOC_AT91SAM9 || SOC_SAMA5
 
 config ATMEL_ST
-	bool
+	bool "Atmel ST timer support" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
 	select CLKSRC_OF
 	select MFD_SYSCON
+	help
+	  Support for the Atmel ST timer.
 
 config CLKSRC_METAG_GENERIC
 	def_bool y if METAG
···
 	  Support for Multi Core Timer controller on Exynos SoCs.
 
 config CLKSRC_SAMSUNG_PWM
-	bool "PWM timer drvier for Samsung S3C, S5P" if COMPILE_TEST
+	bool "PWM timer driver for Samsung S3C, S5P" if COMPILE_TEST
 	depends on GENERIC_CLOCKEVENTS
 	depends on HAS_IOMEM
 	help
···
 	select CLKSRC_MMIO
 	help
 	  Support for Period Interrupt Timer on Freescale Vybrid Family SoCs.
+
+config OXNAS_RPS_TIMER
+	bool "Oxford Semiconductor OXNAS RPS Timers driver" if COMPILE_TEST
+	depends on GENERIC_CLOCKEVENTS
+	select CLKSRC_OF
+	select CLKSRC_MMIO
+	help
+	  This enables support for the Oxford Semiconductor OXNAS RPS timers.
 
 config SYS_SUPPORTS_SH_CMT
         bool
···
 	  Qualcomm SoCs.
 
 config CLKSRC_VERSATILE
-	bool "ARM Versatile (Express) reference platforms clock source"
-	depends on PLAT_VERSATILE && GENERIC_SCHED_CLOCK && !ARCH_USES_GETTIMEOFFSET
+	bool "ARM Versatile (Express) reference platforms clock source" if COMPILE_TEST
+	depends on GENERIC_SCHED_CLOCK && !ARCH_USES_GETTIMEOFFSET
 	select CLKSRC_OF
 	default y if MFD_VEXPRESS_SYSREG
 	help

drivers/clocksource/Makefile

···
 obj-$(CONFIG_CLKSRC_DBX500_PRCMU)	+= clksrc-dbx500-prcmu.o
 obj-$(CONFIG_ARMADA_370_XP_TIMER)	+= time-armada-370-xp.o
 obj-$(CONFIG_ORION_TIMER)	+= time-orion.o
-obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835_timer.o
-obj-$(CONFIG_ARCH_CLPS711X)	+= clps711x-timer.o
-obj-$(CONFIG_ARCH_ATLAS7)	+= timer-atlas7.o
-obj-$(CONFIG_ARCH_MOXART)	+= moxart_timer.o
-obj-$(CONFIG_ARCH_MXS)		+= mxs_timer.o
+obj-$(CONFIG_BCM2835_TIMER)	+= bcm2835_timer.o
+obj-$(CONFIG_CLPS711X_TIMER)	+= clps711x-timer.o
+obj-$(CONFIG_ATLAS7_TIMER)	+= timer-atlas7.o
+obj-$(CONFIG_MOXART_TIMER)	+= moxart_timer.o
+obj-$(CONFIG_MXS_TIMER)		+= mxs_timer.o
 obj-$(CONFIG_CLKSRC_PXA)	+= pxa_timer.o
-obj-$(CONFIG_ARCH_PRIMA2)	+= timer-prima2.o
-obj-$(CONFIG_ARCH_U300)		+= timer-u300.o
+obj-$(CONFIG_PRIMA2_TIMER)	+= timer-prima2.o
+obj-$(CONFIG_U300_TIMER)	+= timer-u300.o
 obj-$(CONFIG_SUN4I_TIMER)	+= sun4i_timer.o
 obj-$(CONFIG_SUN5I_HSTIMER)	+= timer-sun5i.o
 obj-$(CONFIG_MESON6_TIMER)	+= meson6_timer.o
 obj-$(CONFIG_TEGRA_TIMER)	+= tegra20_timer.o
 obj-$(CONFIG_VT8500_TIMER)	+= vt8500_timer.o
-obj-$(CONFIG_ARCH_NSPIRE)	+= zevio-timer.o
-obj-$(CONFIG_ARCH_BCM_MOBILE)	+= bcm_kona_timer.o
+obj-$(CONFIG_NSPIRE_TIMER)	+= zevio-timer.o
+obj-$(CONFIG_BCM_KONA_TIMER)	+= bcm_kona_timer.o
 obj-$(CONFIG_CADENCE_TTC_TIMER)	+= cadence_ttc_timer.o
 obj-$(CONFIG_CLKSRC_EFM32)	+= time-efm32.o
 obj-$(CONFIG_CLKSRC_STM32)	+= timer-stm32.o
···
 obj-$(CONFIG_CLKSRC_PISTACHIO)	+= time-pistachio.o
 obj-$(CONFIG_CLKSRC_TI_32K)	+= timer-ti-32k.o
 obj-$(CONFIG_CLKSRC_NPS)	+= timer-nps.o
+obj-$(CONFIG_OXNAS_RPS_TIMER)	+= timer-oxnas-rps.o
 
 obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o
 obj-$(CONFIG_ARM_GLOBAL_TIMER)		+= arm_global_timer.o
···
 obj-$(CONFIG_ARM_TIMER_SP804)		+= timer-sp804.o
 obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o
 obj-$(CONFIG_ARCH_HAS_TICK_BROADCAST)	+= dummy_timer.o
-obj-$(CONFIG_ARCH_KEYSTONE)		+= timer-keystone.o
-obj-$(CONFIG_ARCH_INTEGRATOR_AP)	+= timer-integrator-ap.o
+obj-$(CONFIG_KEYSTONE_TIMER)		+= timer-keystone.o
+obj-$(CONFIG_INTEGRATOR_AP_TIMER)	+= timer-integrator-ap.o
 obj-$(CONFIG_CLKSRC_VERSATILE)		+= versatile.o
 obj-$(CONFIG_CLKSRC_MIPS_GIC)		+= mips-gic-timer.o
 obj-$(CONFIG_CLKSRC_TANGO_XTAL)		+= tango_xtal.o

drivers/clocksource/arm_arch_timer.c

···
 static bool arch_timer_c3stop;
 static bool arch_timer_mem_use_virtual;
 
+static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
+
+static int __init early_evtstrm_cfg(char *buf)
+{
+	return strtobool(buf, &evtstrm_enable);
+}
+early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
+
 /*
  * Architected system timer support.
  */
···
 		enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
 
 	arch_counter_set_user_access();
-	if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
+	if (evtstrm_enable)
 		arch_timer_configure_evtstream();
 
 	return 0;
···
 	return needs_probing;
 }
 
-static void __init arch_timer_common_init(void)
+static int __init arch_timer_common_init(void)
 {
 	unsigned mask = ARCH_CP15_TIMER | ARCH_MEM_TIMER;
 
 	/* Wait until both nodes are probed if we have two timers */
 	if ((arch_timers_present & mask) != mask) {
 		if (arch_timer_needs_probing(ARCH_MEM_TIMER, arch_timer_mem_of_match))
-			return;
+			return 0;
 		if (arch_timer_needs_probing(ARCH_CP15_TIMER, arch_timer_of_match))
-			return;
+			return 0;
 	}
 
 	arch_timer_banner(arch_timers_present);
 	arch_counter_register(arch_timers_present);
-	arch_timer_arch_init();
+	return arch_timer_arch_init();
 }
 
-static void __init arch_timer_init(void)
+static int __init arch_timer_init(void)
 {
+	int ret;
 	/*
 	 * If HYP mode is available, we know that the physical timer
 	 * has been configured to be accessible from PL1. Use it, so
···
 
 		if (!has_ppi) {
 			pr_warn("arch_timer: No interrupt available, giving up\n");
-			return;
+			return -EINVAL;
 		}
 	}
 
-	arch_timer_register();
-	arch_timer_common_init();
+	ret = arch_timer_register();
+	if (ret)
+		return ret;
+
+	ret = arch_timer_common_init();
+	if (ret)
+		return ret;
 
 	arch_timer_kvm_info.virtual_irq = arch_timer_ppi[VIRT_PPI];
+	
+	return 0;
 }
 
-static void __init arch_timer_of_init(struct device_node *np)
+static int __init arch_timer_of_init(struct device_node *np)
 {
 	int i;
 
 	if (arch_timers_present & ARCH_CP15_TIMER) {
 		pr_warn("arch_timer: multiple nodes in dt, skipping\n");
-		return;
+		return 0;
 	}
 
 	arch_timers_present |= ARCH_CP15_TIMER;
···
 	    of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
 		arch_timer_uses_ppi = PHYS_SECURE_PPI;
 
-	arch_timer_init();
+	return arch_timer_init();
 }
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init);
 CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init);
 
-static void __init arch_timer_mem_init(struct device_node *np)
+static int __init arch_timer_mem_init(struct device_node *np)
 {
 	struct device_node *frame, *best_frame = NULL;
 	void __iomem *cntctlbase, *base;
-	unsigned int irq;
+	unsigned int irq, ret = -EINVAL;
 	u32 cnttidr;
 
 	arch_timers_present |= ARCH_MEM_TIMER;
 	cntctlbase = of_iomap(np, 0);
 	if (!cntctlbase) {
 		pr_err("arch_timer: Can't find CNTCTLBase\n");
-		return;
+		return -ENXIO;
 	}
 
 	cnttidr = readl_relaxed(cntctlbase + CNTTIDR);
···
 		best_frame = of_node_get(frame);
 	}
 
+	ret= -ENXIO;
 	base = arch_counter_base = of_iomap(best_frame, 0);
 	if (!base) {
 		pr_err("arch_timer: Can't map frame's registers\n");
···
 	else
 		irq = irq_of_parse_and_map(best_frame, 0);
 
+	ret = -EINVAL;
 	if (!irq) {
 		pr_err("arch_timer: Frame missing %s irq",
 		       arch_timer_mem_use_virtual ? "virt" : "phys");
···
 	}
 
 	arch_timer_detect_rate(base, np);
-	arch_timer_mem_register(base, irq);
-	arch_timer_common_init();
+	ret = arch_timer_mem_register(base, irq);
+	if (ret)
+		goto out;
+
+	return arch_timer_common_init();
 out:
 	iounmap(cntctlbase);
 	of_node_put(best_frame);
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
 		       arch_timer_mem_init);

drivers/clocksource/arm_global_timer.c

···
 	register_current_timer_delay(&gt_delay_timer);
 }
 
-static void __init gt_clocksource_init(void)
+static int __init gt_clocksource_init(void)
 {
 	writel(0, gt_base + GT_CONTROL);
 	writel(0, gt_base + GT_COUNTER0);
···
 #ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
 	sched_clock_register(gt_sched_clock_read, 64, gt_clk_rate);
 #endif
-	clocksource_register_hz(&gt_clocksource, gt_clk_rate);
+	return clocksource_register_hz(&gt_clocksource, gt_clk_rate);
 }
 
 static int gt_cpu_notify(struct notifier_block *self, unsigned long action,
···
 	.notifier_call = gt_cpu_notify,
 };
 
-static void __init global_timer_of_register(struct device_node *np)
+static int __init global_timer_of_register(struct device_node *np)
 {
 	struct clk *gt_clk;
 	int err = 0;
···
 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9
 	    && (read_cpuid_id() & 0xf0000f) < 0x200000) {
 		pr_warn("global-timer: non support for this cpu version.\n");
-		return;
+		return -ENOSYS;
 	}
 
 	gt_ppi = irq_of_parse_and_map(np, 0);
 	if (!gt_ppi) {
 		pr_warn("global-timer: unable to parse irq\n");
-		return;
+		return -EINVAL;
 	}
 
 	gt_base = of_iomap(np, 0);
 	if (!gt_base) {
 		pr_warn("global-timer: invalid base address\n");
-		return;
+		return -ENXIO;
 	}
 
 	gt_clk = of_clk_get(np, 0);
···
 	}
 
 	/* Immediately configure the timer on the boot CPU */
-	gt_clocksource_init();
-	gt_clockevents_init(this_cpu_ptr(gt_evt));
+	err = gt_clocksource_init();
+	if (err)
+		goto out_irq;
+	
+	err = gt_clockevents_init(this_cpu_ptr(gt_evt));
+	if (err)
+		goto out_irq;
+
 	gt_delay_timer_init();
 
-	return;
+	return 0;
 
 out_irq:
 	free_percpu_irq(gt_ppi, gt_evt);
···
 out_unmap:
 	iounmap(gt_base);
 	WARN(err, "ARM Global timer register failed (%d)\n", err);
+
+	return err;
 }
 
 /* Only tested on r2p2 and r3p0  */

drivers/clocksource/armv7m_systick.c

···
 #include <linux/kernel.h>
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
+#include <linux/io.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/clk.h>
···
 
 #define SYSTICK_LOAD_RELOAD_MASK 0x00FFFFFF
 
-static void __init system_timer_of_register(struct device_node *np)
+static int __init system_timer_of_register(struct device_node *np)
 {
 	struct clk *clk = NULL;
 	void __iomem *base;
···
 	base = of_iomap(np, 0);
 	if (!base) {
 		pr_warn("system-timer: invalid base address\n");
-		return;
+		return -ENXIO;
 	}
 
 	ret = of_property_read_u32(np, "clock-frequency", &rate);
 	if (ret) {
 		clk = of_clk_get(np, 0);
-		if (IS_ERR(clk))
+		if (IS_ERR(clk)) {
+			ret = PTR_ERR(clk);
 			goto out_unmap;
+		}
 
 		ret = clk_prepare_enable(clk);
 		if (ret)
 			goto out_clk_put;
 
 		rate = clk_get_rate(clk);
-		if (!rate)
+		if (!rate) {
+			ret = -EINVAL;
 			goto out_clk_disable;
+		}
 	}
 
 	writel_relaxed(SYSTICK_LOAD_RELOAD_MASK, base + SYST_RVR);
···
 
 	pr_info("ARM System timer initialized as clocksource\n");
 
-	return;
+	return 0;
 
 out_clk_disable:
 	clk_disable_unprepare(clk);
···
 out_unmap:
 	iounmap(base);
 	pr_warn("ARM System timer register failed (%d)\n", ret);
+
+	return ret;
 }
 
 CLOCKSOURCE_OF_DECLARE(arm_systick, "arm,armv7m-systick",

drivers/clocksource/asm9260_timer.c

···
  * Timer initialization
  * ---------------------------------------------------------------------------
  */
-static void __init asm9260_timer_init(struct device_node *np)
+static int __init asm9260_timer_init(struct device_node *np)
 {
 	int irq;
 	struct clk *clk;
···
 	unsigned long rate;
 
 	priv.base = of_io_request_and_map(np, 0, np->name);
-	if (IS_ERR(priv.base))
-		panic("%s: unable to map resource", np->name);
+	if (IS_ERR(priv.base)) {
+		pr_err("%s: unable to map resource", np->name);
+		return PTR_ERR(priv.base);
+	}
 
 	clk = of_clk_get(np, 0);
 
 	ret = clk_prepare_enable(clk);
-	if (ret)
-		panic("Failed to enable clk!\n");
+	if (ret) {
+		pr_err("Failed to enable clk!\n");
+		return ret;
+	}
 
 	irq = irq_of_parse_and_map(np, 0);
 	ret = request_irq(irq, asm9260_timer_interrupt, IRQF_TIMER,
 			DRIVER_NAME, &event_dev);
-	if (ret)
-		panic("Failed to setup irq!\n");
+	if (ret) {
+		pr_err("Failed to setup irq!\n");
+		return ret;
+	}
 
 	/* set all timers for count-up */
 	writel_relaxed(BM_DIR_DEFAULT, priv.base + HW_DIR);
···
 	priv.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
 	event_dev.cpumask = cpumask_of(0);
 	clockevents_config_and_register(&event_dev, rate, 0x2c00, 0xfffffffe);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(asm9260_timer, "alphascale,asm9260-timer",
 		asm9260_timer_init);

drivers/clocksource/bcm2835_timer.c

···
 	}
 }
 
-static void __init bcm2835_timer_init(struct device_node *node)
+static int __init bcm2835_timer_init(struct device_node *node)
 {
 	void __iomem *base;
 	u32 freq;
-	int irq;
+	int irq, ret;
 	struct bcm2835_timer *timer;
 
 	base = of_iomap(node, 0);
-	if (!base)
-		panic("Can't remap registers");
+	if (!base) {
+		pr_err("Can't remap registers");
+		return -ENXIO;
+	}
 
-	if (of_property_read_u32(node, "clock-frequency", &freq))
-		panic("Can't read clock-frequency");
+	ret = of_property_read_u32(node, "clock-frequency", &freq);
+	if (ret) {
+		pr_err("Can't read clock-frequency");
+		return ret;
+	}
 
 	system_clock = base + REG_COUNTER_LO;
 	sched_clock_register(bcm2835_sched_read, 32, freq);
···
 		freq, 300, 32, clocksource_mmio_readl_up);
 
 	irq = irq_of_parse_and_map(node, DEFAULT_TIMER);
-	if (irq <= 0)
-		panic("Can't parse IRQ");
+	if (irq <= 0) {
+		pr_err("Can't parse IRQ");
+		return -EINVAL;
+	}
 
 	timer = kzalloc(sizeof(*timer), GFP_KERNEL);
-	if (!timer)
-		panic("Can't allocate timer struct\n");
+	if (!timer) {
+		pr_err("Can't allocate timer struct\n");
+		return -ENOMEM;
+	}
 
 	timer->control = base + REG_CONTROL;
 	timer->compare = base + REG_COMPARE(DEFAULT_TIMER);
···
 	timer->act.dev_id = timer;
 	timer->act.handler = bcm2835_time_interrupt;
 
-	if (setup_irq(irq, &timer->act))
-		panic("Can't set up timer IRQ\n");
+	ret = setup_irq(irq, &timer->act);
+	if (ret) {
+		pr_err("Can't set up timer IRQ\n");
+		return ret;
+	}
 
 	clockevents_config_and_register(&timer->evt, freq, 0xf, 0xffffffff);
 
 	pr_info("bcm2835: system timer (irq = %d)\n", irq);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(bcm2835, "brcm,bcm2835-system-timer",
 			bcm2835_timer_init);

drivers/clocksource/bcm_kona_timer.c

···
 #include <linux/clk.h>
 
 #include <linux/io.h>
-#include <asm/mach/time.h>
 
 #include <linux/of.h>
 #include <linux/of_address.h>
···
 	.handler = kona_timer_interrupt,
 };
 
-static void __init kona_timer_init(struct device_node *node)
+static int __init kona_timer_init(struct device_node *node)
 {
 	u32 freq;
 	struct clk *external_clk;
-
-	if (!of_device_is_available(node)) {
-		pr_info("Kona Timer v1 marked as disabled in device tree\n");
-		return;
-	}
 
 	external_clk = of_clk_get_by_name(node, NULL);
 
···
 		arch_timer_rate = freq;
 	} else {
 		pr_err("Kona Timer v1 unable to determine clock-frequency");
-		return;
+		return -EINVAL;
 	}
 
 	/* Setup IRQ numbers */
···
 	kona_timer_clockevents_init();
 	setup_irq(timers.tmr_irq, &kona_timer_irq);
 	kona_timer_set_next_event((arch_timer_rate / HZ), NULL);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(brcm_kona, "brcm,kona-timer", kona_timer_init);

drivers/clocksource/cadence_ttc_timer.c

···
 	return NOTIFY_DONE;
 }
 
-static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
+static int __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
 					 u32 timer_width)
 {
 	struct ttc_timer_clocksource *ttccs;
 	int err;
 
 	ttccs = kzalloc(sizeof(*ttccs), GFP_KERNEL);
-	if (WARN_ON(!ttccs))
-		return;
+	if (!ttccs)
+		return -ENOMEM;
 
 	ttccs->ttc.clk = clk;
 
 	err = clk_prepare_enable(ttccs->ttc.clk);
-	if (WARN_ON(err)) {
+	if (err) {
 		kfree(ttccs);
-		return;
+		return err;
 	}
 
 	ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk);
···
 	ttccs->ttc.clk_rate_change_nb.notifier_call =
 		ttc_rate_change_clocksource_cb;
 	ttccs->ttc.clk_rate_change_nb.next = NULL;
-	if (clk_notifier_register(ttccs->ttc.clk,
-				&ttccs->ttc.clk_rate_change_nb))
+
+	err = clk_notifier_register(ttccs->ttc.clk,
+				    &ttccs->ttc.clk_rate_change_nb);
+	if (err)
 		pr_warn("Unable to register clock notifier.\n");
 
 	ttccs->ttc.base_addr = base;
···
 		     ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
 
 	err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE);
-	if (WARN_ON(err)) {
+	if (err) {
 		kfree(ttccs);
-		return;
+		return err;
 	}
 
 	ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
 	sched_clock_register(ttc_sched_clock_read, timer_width,
 			     ttccs->ttc.freq / PRESCALE);
+
+	return 0;
 }
 
 static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
···
 	}
 }
 
-static void __init ttc_setup_clockevent(struct clk *clk,
-						void __iomem *base, u32 irq)
+static int __init ttc_setup_clockevent(struct clk *clk,
+				       void __iomem *base, u32 irq)
 {
 	struct ttc_timer_clockevent *ttcce;
 	int err;
 
 	ttcce = kzalloc(sizeof(*ttcce), GFP_KERNEL);
-	if (WARN_ON(!ttcce))
-		return;
+	if (!ttcce)
+		return -ENOMEM;
 
 	ttcce->ttc.clk = clk;
 
 	err = clk_prepare_enable(ttcce->ttc.clk);
-	if (WARN_ON(err)) {
+	if (err) {
 		kfree(ttcce);
-		return;
+		return err;
 	}
 
 	ttcce->ttc.clk_rate_change_nb.notifier_call =
 		ttc_rate_change_clockevent_cb;
 	ttcce->ttc.clk_rate_change_nb.next = NULL;
-	if (clk_notifier_register(ttcce->ttc.clk,
-				&ttcce->ttc.clk_rate_change_nb))
+
+	err = clk_notifier_register(ttcce->ttc.clk,
+				    &ttcce->ttc.clk_rate_change_nb);
+	if (err) {
 		pr_warn("Unable to register clock notifier.\n");
+		return err;
+	}
+
 	ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk);
 
 	ttcce->ttc.base_addr = base;
···
 
 	err = request_irq(irq, ttc_clock_event_interrupt,
 			  IRQF_TIMER, ttcce->ce.name, ttcce);
-	if (WARN_ON(err)) {
+	if (err) {
 		kfree(ttcce);
-		return;
+		return err;
 	}
 
 	clockevents_config_and_register(&ttcce->ce,
 			ttcce->ttc.freq / PRESCALE, 1, 0xfffe);
+
+	return 0;
 }
 
 /**
···
  * Initializes the timer hardware and register the clock source and clock event
  * timers with Linux kernal timer framework
  */
-static void __init ttc_timer_init(struct device_node *timer)
+static int __init ttc_timer_init(struct device_node *timer)
 {
 	unsigned int irq;
 	void __iomem *timer_baseaddr;
 	struct clk *clk_cs, *clk_ce;
 	static int initialized;
-	int clksel;
+	int clksel, ret;
 	u32 timer_width = 16;
 
 	if (initialized)
-		return;
+		return 0;
 
 	initialized = 1;
 
···
 	timer_baseaddr = of_iomap(timer, 0);
 	if (!timer_baseaddr) {
 		pr_err("ERROR: invalid timer base address\n");
-		BUG();
+		return -ENXIO;
 	}
 
 	irq = irq_of_parse_and_map(timer, 1);
 	if (irq <= 0) {
 		pr_err("ERROR: invalid interrupt number\n");
-		BUG();
+		return -EINVAL;
 	}
 
 	of_property_read_u32(timer, "timer-width", &timer_width);
···
 	clk_cs = of_clk_get(timer, clksel);
 	if (IS_ERR(clk_cs)) {
 		pr_err("ERROR: timer input clock not found\n");
-		BUG();
+		return PTR_ERR(clk_cs);
 	}
 
 	clksel = readl_relaxed(timer_baseaddr + 4 + TTC_CLK_CNTRL_OFFSET);
···
 	clk_ce = of_clk_get(timer, clksel);
 	if (IS_ERR(clk_ce)) {
 		pr_err("ERROR: timer input clock not found\n");
-		BUG();
+		return PTR_ERR(clk_ce);
 	}
 
-	ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width);
-	ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq);
+	ret = ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width);
+	if (ret)
+		return ret;
+
+	ret = ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq);
+	if (ret)
+		return ret;
 
 	pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(ttc, "cdns,ttc", ttc_timer_init);

drivers/clocksource/clksrc-dbx500-prcmu.c

···
 
 #endif
 
-static void __init clksrc_dbx500_prcmu_init(struct device_node *node)
+static int __init clksrc_dbx500_prcmu_init(struct device_node *node)
 {
 	clksrc_dbx500_timer_base = of_iomap(node, 0);
 
···
 #ifdef CONFIG_CLKSRC_DBX500_PRCMU_SCHED_CLOCK
 	sched_clock_register(dbx500_prcmu_sched_clock_read, 32, RATE_32K);
 #endif
-	clocksource_register_hz(&clocksource_dbx500_prcmu, RATE_32K);
+	return clocksource_register_hz(&clocksource_dbx500_prcmu, RATE_32K);
 }
 CLOCKSOURCE_OF_DECLARE(dbx500_prcmu, "stericsson,db8500-prcmu-timer-4",
 		       clksrc_dbx500_prcmu_init);

drivers/clocksource/clksrc-probe.c

···
 {
 	struct device_node *np;
 	const struct of_device_id *match;
-	of_init_fn_1 init_func;
+	of_init_fn_1_ret init_func_ret;
 	unsigned clocksources = 0;
+	int ret;
 
 	for_each_matching_node_and_match(np, __clksrc_of_table, &match) {
 		if (!of_device_is_available(np))
 			continue;
 
-		init_func = match->data;
-		init_func(np);
+		init_func_ret = match->data;
+
+		ret = init_func_ret(np);
+		if (ret) {
+			pr_err("Failed to initialize '%s': %d",
+			       of_node_full_name(np), ret);
+			continue;
+		}
+
 		clocksources++;
 	}
 

drivers/clocksource/clksrc_st_lpc.c

···
 	return 0;
 }
 
-static void __init st_clksrc_of_register(struct device_node *np)
+static int __init st_clksrc_of_register(struct device_node *np)
 {
 	int ret;
 	uint32_t mode;
···
 	ret = of_property_read_u32(np, "st,lpc-mode", &mode);
 	if (ret) {
 		pr_err("clksrc-st-lpc: An LPC mode must be provided\n");
-		return;
+		return ret;
 	}
 
 	/* LPC can either run as a Clocksource or in RTC or WDT mode */
 	if (mode != ST_LPC_MODE_CLKSRC)
-		return;
+		return 0;
 
 	ddata.base = of_iomap(np, 0);
 	if (!ddata.base) {
 		pr_err("clksrc-st-lpc: Unable to map iomem\n");
-		return;
+		return -ENXIO;
 	}
 
-	if (st_clksrc_setup_clk(np)) {
+	ret = st_clksrc_setup_clk(np);
+	if (ret) {
 		iounmap(ddata.base);
-		return;
+		return ret;
 	}
 
-	if (st_clksrc_init()) {
+	ret = st_clksrc_init();
+	if (ret) {
 		clk_disable_unprepare(ddata.clk);
 		clk_put(ddata.clk);
 		iounmap(ddata.base);
-		return;
+		return ret;
 	}
 
 	pr_info("clksrc-st-lpc: clocksource initialised - running @ %luHz\n",
 		clk_get_rate(ddata.clk));
+
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(ddata, "st,stih407-lpc", st_clksrc_of_register);

drivers/clocksource/clps711x-timer.c

···
 }
 
 #ifdef CONFIG_CLKSRC_OF
-static void __init clps711x_timer_init(struct device_node *np)
+static int __init clps711x_timer_init(struct device_node *np)
 {
 	unsigned int irq = irq_of_parse_and_map(np, 0);
 	struct clk *clock = of_clk_get(np, 0);
···
 
 	switch (of_alias_get_id(np, "timer")) {
 	case CLPS711X_CLKSRC_CLOCKSOURCE:
-		BUG_ON(_clps711x_clksrc_init(clock, base));
-		break;
+		return _clps711x_clksrc_init(clock, base);
 	case CLPS711X_CLKSRC_CLOCKEVENT:
-		BUG_ON(_clps711x_clkevt_init(clock, base, irq));
-		break;
+		return _clps711x_clkevt_init(clock, base, irq);
 	default:
-		break;
+		return -EINVAL;
 	}
 }
 CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,clps711x-timer", clps711x_timer_init);

drivers/clocksource/dw_apb_timer_of.c

···
 #endif
 
 static int num_called;
-static void __init dw_apb_timer_init(struct device_node *timer)
+static int __init dw_apb_timer_init(struct device_node *timer)
 {
 	switch (num_called) {
 	case 0:
···
 	}
 
 	num_called++;
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(pc3x2_timer, "picochip,pc3x2-timer", dw_apb_timer_init);
 CLOCKSOURCE_OF_DECLARE(apb_timer_osc, "snps,dw-apb-timer-osc", dw_apb_timer_init);

drivers/clocksource/exynos_mct.c

···
 	return exynos4_read_count_32();
 }
 
-static void __init exynos4_clocksource_init(void)
+static int __init exynos4_clocksource_init(void)
 {
 	exynos4_mct_frc_start();
 
···
 		panic("%s: can't register clocksource\n", mct_frc.name);
 
 	sched_clock_register(exynos4_read_sched_clock, 32, clk_rate);
+
+	return 0;
 }
 
 static void exynos4_mct_comp0_stop(void)
···
 	.dev_id		= &mct_comp_device,
 };
 
-static void exynos4_clockevent_init(void)
+static int exynos4_clockevent_init(void)
 {
 	mct_comp_device.cpumask = cpumask_of(0);
 	clockevents_config_and_register(&mct_comp_device, clk_rate,
 					0xf, 0xffffffff);
 	setup_irq(mct_irqs[MCT_G0_IRQ], &mct_comp_event_irq);
+
+	return 0;
 }
 
 static DEFINE_PER_CPU(struct mct_clock_event_device, percpu_mct_tick);
···
 	.notifier_call = exynos4_mct_cpu_notify,
 };
 
-static void __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
+static int __init exynos4_timer_resources(struct device_node *np, void __iomem *base)
 {
 	int err, cpu;
 	struct mct_clock_event_device *mevt = this_cpu_ptr(&percpu_mct_tick);
···
 
 	/* Immediately configure the timer on the boot CPU */
 	exynos4_local_timer_setup(mevt);
-	return;
+	return 0;
 
 out_irq:
 	free_percpu_irq(mct_irqs[MCT_L0_IRQ], &percpu_mct_tick);
+	return err;
 }
 
-static void __init mct_init_dt(struct device_node *np, unsigned int int_type)
+static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
 {
 	u32 nr_irqs, i;
+	int ret;
 
 	mct_int_type = int_type;
 
···
 	for (i = MCT_L0_IRQ; i < nr_irqs; i++)
 		mct_irqs[i] = irq_of_parse_and_map(np, i);
 
-	exynos4_timer_resources(np, of_iomap(np, 0));
-	exynos4_clocksource_init();
-	exynos4_clockevent_init();
+	ret = exynos4_timer_resources(np, of_iomap(np, 0));
+	if (ret)
+		return ret;
+
+	ret = exynos4_clocksource_init();
+	if (ret)
+		return ret;
+
+	return exynos4_clockevent_init();
 }
 
 
-static void __init mct_init_spi(struct device_node *np)
+static int __init mct_init_spi(struct device_node *np)
 {
 	return mct_init_dt(np, MCT_INT_SPI);
 }
 
-static void __init mct_init_ppi(struct device_node *np)
+static int __init mct_init_ppi(struct device_node *np)
 {
 	return mct_init_dt(np, MCT_INT_PPI);
 }

drivers/clocksource/fsl_ftm_timer.c

···
 	return 0;
 }
 
-static void __init ftm_timer_init(struct device_node *np)
+static int __init ftm_timer_init(struct device_node *np)
 {
 	unsigned long freq;
-	int irq;
+	int ret, irq;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
-		return;
+		return -ENOMEM;
 
+	ret = -ENXIO;
 	priv->clkevt_base = of_iomap(np, 0);
 	if (!priv->clkevt_base) {
 		pr_err("ftm: unable to map event timer registers\n");
···
 		goto err;
 	}
 
+	ret = -EINVAL;
 	irq = irq_of_parse_and_map(np, 0);
 	if (irq <= 0) {
 		pr_err("ftm: unable to get IRQ from DT, %d\n", irq);
···
 	if (!freq)
 		goto err;
 
-	if (ftm_calc_closest_round_cyc(freq))
+	ret = ftm_calc_closest_round_cyc(freq);
+	if (ret)
 		goto err;
 
-	if (ftm_clocksource_init(freq))
+	ret = ftm_clocksource_init(freq);
+	if (ret)
 		goto err;
 
-	if (ftm_clockevent_init(freq, irq))
+	ret = ftm_clockevent_init(freq, irq);
+	if (ret)
 		goto err;
 
-	return;
+	return 0;
 
 err:
 	kfree(priv);
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(flextimer, "fsl,ftm-timer", ftm_timer_init);

drivers/clocksource/h8300_timer16.c

···
 #define REG_CH   0
 #define REG_COMM 1
 
-static void __init h8300_16timer_init(struct device_node *node)
+static int __init h8300_16timer_init(struct device_node *node)
 {
 	void __iomem *base[2];
 	int ret, irq;
···
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("failed to get clock for clocksource\n");
-		return;
+		return PTR_ERR(clk);
 	}
 
+	ret = -ENXIO;
 	base[REG_CH] = of_iomap(node, 0);
 	if (!base[REG_CH]) {
 		pr_err("failed to map registers for clocksource\n");
···
 		goto unmap_ch;
 	}
 
+	ret = -EINVAL;
 	irq = irq_of_parse_and_map(node, 0);
 	if (!irq) {
 		pr_err("failed to get irq for clockevent\n");
···
 
 	clocksource_register_hz(&timer16_priv.cs,
 				clk_get_rate(clk) / 8);
-	return;
+	return 0;
 
 unmap_comm:
 	iounmap(base[REG_COMM]);
···
 	iounmap(base[REG_CH]);
 free_clk:
 	clk_put(clk);
+	return ret;
 }
 
-CLOCKSOURCE_OF_DECLARE(h8300_16bit, "renesas,16bit-timer", h8300_16timer_init);
+CLOCKSOURCE_OF_DECLARE(h8300_16bit, "renesas,16bit-timer",
+			   h8300_16timer_init);

drivers/clocksource/h8300_timer8.c

···
 	},
 };
 
-static void __init h8300_8timer_init(struct device_node *node)
+static int __init h8300_8timer_init(struct device_node *node)
 {
 	void __iomem *base;
-	int irq;
+	int irq, ret;
 	struct clk *clk;
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("failed to get clock for clockevent\n");
-		return;
+		return PTR_ERR(clk);
 	}
 
+	ret = ENXIO;
 	base = of_iomap(node, 0);
 	if (!base) {
 		pr_err("failed to map registers for clockevent\n");
 		goto free_clk;
 	}
 
+	ret = -EINVAL;
 	irq = irq_of_parse_and_map(node, 0);
 	if (!irq) {
 		pr_err("failed to get irq for clockevent\n");
···
 	clockevents_config_and_register(&timer8_priv.ced,
 					timer8_priv.rate, 1, 0x0000ffff);
 
-	return;
+	return 0;
 unmap_reg:
 	iounmap(base);
 free_clk:
 	clk_put(clk);
+	return ret;
 }
 
 CLOCKSOURCE_OF_DECLARE(h8300_8bit, "renesas,8bit-timer", h8300_8timer_init);

drivers/clocksource/h8300_tpu.c

···
 #define CH_L 0
 #define CH_H 1
 
-static void __init h8300_tpu_init(struct device_node *node)
+static int __init h8300_tpu_init(struct device_node *node)
 {
 	void __iomem *base[2];
 	struct clk *clk;
+	int ret = -ENXIO;
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("failed to get clock for clocksource\n");
-		return;
+		return PTR_ERR(clk);
 	}
 
 	base[CH_L] = of_iomap(node, CH_L);
···
 	tpu_priv.mapbase1 = base[CH_L];
 	tpu_priv.mapbase2 = base[CH_H];
 
-	clocksource_register_hz(&tpu_priv.cs, clk_get_rate(clk) / 64);
-
-	return;
+	return clocksource_register_hz(&tpu_priv.cs, clk_get_rate(clk) / 64);
 
 unmap_L:
 	iounmap(base[CH_H]);
 free_clk:
 	clk_put(clk);
+	return ret;
 }
 
 CLOCKSOURCE_OF_DECLARE(h8300_tpu, "renesas,tpu", h8300_tpu_init);

drivers/clocksource/meson6_timer.c

···
 	.dev_id		= &meson6_clockevent,
 };
 
-static void __init meson6_timer_init(struct device_node *node)
+static int __init meson6_timer_init(struct device_node *node)
 {
 	u32 val;
 	int ret, irq;
 
 	timer_base = of_io_request_and_map(node, 0, "meson6-timer");
-	if (IS_ERR(timer_base))
-		panic("Can't map registers");
+	if (IS_ERR(timer_base)) {
+		pr_err("Can't map registers");
+		return -ENXIO;
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("Can't parse IRQ");
+	if (irq <= 0) {
+		pr_err("Can't parse IRQ");
+		return -EINVAL;
+	}
 
 	/* Set 1us for timer E */
 	val = readl(timer_base + TIMER_ISA_MUX);
···
 	meson6_clkevt_time_stop(CED_ID);
 
 	ret = setup_irq(irq, &meson6_timer_irq);
-	if (ret)
+	if (ret) {
 		pr_warn("failed to setup irq %d\n", irq);
+		return ret;
+	}
 
 	meson6_clockevent.cpumask = cpu_possible_mask;
 	meson6_clockevent.irq = irq;
 
 	clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
 					1, 0xfffe);
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(meson6, "amlogic,meson6-timer",
 		       meson6_timer_init);

drivers/clocksource/mips-gic-timer.c

···
 	.archdata	= { .vdso_clock_mode = VDSO_CLOCK_GIC },
 };
 
-static void __init __gic_clocksource_init(void)
+static int __init __gic_clocksource_init(void)
 {
 	int ret;
 
···
 	ret = clocksource_register_hz(&gic_clocksource, gic_frequency);
 	if (ret < 0)
 		pr_warn("GIC: Unable to register clocksource\n");
+
+	return ret;
 }
 
 void __init gic_clocksource_init(unsigned int frequency)
···
 	struct clk *clk;
 	int ret;
 
-	if (WARN_ON(!gic_present || !node->parent ||
-		    !of_device_is_compatible(node->parent, "mti,gic")))
-		return;
+	if (!gic_present || !node->parent ||
+	    !of_device_is_compatible(node->parent, "mti,gic")) {
+		pr_warn("No DT definition for the mips gic driver");
+		return -ENXIO;
+	}
 
 	clk = of_clk_get(node, 0);
 	if (!IS_ERR(clk)) {
 		if (clk_prepare_enable(clk) < 0) {
 			pr_err("GIC failed to enable clock\n");
 			clk_put(clk);
-			return;
+			return PTR_ERR(clk);
 		}
 
 		gic_frequency = clk_get_rate(clk);
 	} else if (of_property_read_u32(node, "clock-frequency",
 					&gic_frequency)) {
 		pr_err("GIC frequency not specified.\n");
-		return;
+		return -EINVAL;;
 	}
 	gic_timer_irq = irq_of_parse_and_map(node, 0);
 	if (!gic_timer_irq) {
 		pr_err("GIC timer IRQ not specified.\n");
-		return;
+		return -EINVAL;;
 	}
 
-	__gic_clocksource_init();
+	ret = __gic_clocksource_init();
+	if (ret)
+		return ret;
 
 	ret = gic_clockevent_init();
 	if (!ret && !IS_ERR(clk)) {
···
 
 	/* And finally start the counter */
 	gic_start_count();
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(mips_gic_timer, "mti,gic-timer",
 		       gic_clocksource_of_init);

drivers/clocksource/moxart_timer.c

···
 	.dev_id		= &moxart_clockevent,
 };
 
-static void __init moxart_timer_init(struct device_node *node)
+static int __init moxart_timer_init(struct device_node *node)
 {
 	int ret, irq;
 	unsigned long pclk;
 	struct clk *clk;
 
 	base = of_iomap(node, 0);
-	if (!base)
-		panic("%s: of_iomap failed\n", node->full_name);
+	if (!base) {
+		pr_err("%s: of_iomap failed\n", node->full_name);
+		return -ENXIO;
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("%s: irq_of_parse_and_map failed\n", node->full_name);
+	if (irq <= 0) {
+		pr_err("%s: irq_of_parse_and_map failed\n", node->full_name);
+		return -EINVAL;
+	}
 
 	ret = setup_irq(irq, &moxart_timer_irq);
-	if (ret)
-		panic("%s: setup_irq failed\n", node->full_name);
+	if (ret) {
+		pr_err("%s: setup_irq failed\n", node->full_name);
+		return ret;
+	}
 
 	clk = of_clk_get(node, 0);
-	if (IS_ERR(clk))
-		panic("%s: of_clk_get failed\n", node->full_name);
+	if (IS_ERR(clk))  {
+		pr_err("%s: of_clk_get failed\n", node->full_name);
+		return PTR_ERR(clk);
+	}
 
 	pclk = clk_get_rate(clk);
 
-	if (clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT,
-				  "moxart_timer", pclk, 200, 32,
-				  clocksource_mmio_readl_down))
-		panic("%s: clocksource_mmio_init failed\n", node->full_name);
+	ret = clocksource_mmio_init(base + TIMER2_BASE + REG_COUNT,
+				    "moxart_timer", pclk, 200, 32,
+				    clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("%s: clocksource_mmio_init failed\n", node->full_name);
+		return ret;
+	}
 
 	clock_count_per_tick = DIV_ROUND_CLOSEST(pclk, HZ);
 
···
 	 */
 	clockevents_config_and_register(&moxart_clockevent, pclk,
 					0x4, 0xfffffffe);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(moxart, "moxa,moxart-timer", moxart_timer_init);

drivers/clocksource/mps2-timer.c

···
 	return ret;
 }
 
-static void __init mps2_timer_init(struct device_node *np)
+static int __init mps2_timer_init(struct device_node *np)
 {
 	static int has_clocksource, has_clockevent;
 	int ret;
···
 		ret = mps2_clocksource_init(np);
 		if (!ret) {
 			has_clocksource = 1;
-			return;
+			return 0;
 		}
 	}
 
···
 		ret = mps2_clockevent_init(np);
 		if (!ret) {
 			has_clockevent = 1;
-			return;
+			return 0;
 		}
 	}
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(mps2_timer, "arm,mps2-timer", mps2_timer_init);

drivers/clocksource/mtk_timer.c

···
 			evt->gpt_base + GPT_IRQ_EN_REG);
 }
 
-static void __init mtk_timer_init(struct device_node *node)
+static int __init mtk_timer_init(struct device_node *node)
 {
 	struct mtk_clock_event_device *evt;
 	struct resource res;
···
 
 	evt = kzalloc(sizeof(*evt), GFP_KERNEL);
 	if (!evt)
-		return;
+		return -ENOMEM;
 
 	evt->dev.name = "mtk_tick";
 	evt->dev.rating = 300;
···
 
 	mtk_timer_enable_irq(evt, GPT_CLK_EVT);
 
-	return;
+	return 0;
 
 err_clk_disable:
 	clk_disable_unprepare(clk);
···
 	release_mem_region(res.start, resource_size(&res));
 err_kzalloc:
 	kfree(evt);
+
+	return -EINVAL;
 }
 CLOCKSOURCE_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_timer_init);

drivers/clocksource/mxs_timer.c

···
 #include <linux/stmp_device.h>
 #include <linux/sched_clock.h>
 
-#include <asm/mach/time.h>
-
 /*
  * There are 2 versions of the timrot on Freescale MXS-based SoCs.
  * The v1 on MX23 only gets 16 bits counter, while v2 on MX28
···
 	return 0;
 }
 
-static void __init mxs_timer_init(struct device_node *np)
+static int __init mxs_timer_init(struct device_node *np)
 {
 	struct clk *timer_clk;
-	int irq;
+	int irq, ret;
 
 	mxs_timrot_base = of_iomap(np, 0);
 	WARN_ON(!mxs_timrot_base);
···
 	timer_clk = of_clk_get(np, 0);
 	if (IS_ERR(timer_clk)) {
 		pr_err("%s: failed to get clk\n", __func__);
-		return;
+		return PTR_ERR(timer_clk);
 	}
 
-	clk_prepare_enable(timer_clk);
+	ret = clk_prepare_enable(timer_clk);
+	if (ret)
+		return ret;
 
 	/*
 	 * Initialize timers to a known state
···
 			mxs_timrot_base + HW_TIMROT_FIXED_COUNTn(1));
 
 	/* init and register the timer to the framework */
-	mxs_clocksource_init(timer_clk);
-	mxs_clockevent_init(timer_clk);
+	ret = mxs_clocksource_init(timer_clk);
+	if (ret)
+		return ret;
+
+	ret = mxs_clockevent_init(timer_clk);
+	if (ret)
+		return ret;
 
 	/* Make irqs happen */
 	irq = irq_of_parse_and_map(np, 0);
-	setup_irq(irq, &mxs_timer_irq);
+	if (irq <= 0)
+		return -EINVAL;
+
+	return setup_irq(irq, &mxs_timer_irq);
 }
 CLOCKSOURCE_OF_DECLARE(mxs, "fsl,timrot", mxs_timer_init);

drivers/clocksource/nomadik-mtu.c

···
 	.dev_id		= &nmdk_clkevt,
 };
 
-static void __init nmdk_timer_init(void __iomem *base, int irq,
+static int __init nmdk_timer_init(void __iomem *base, int irq,
 				   struct clk *pclk, struct clk *clk)
 {
 	unsigned long rate;
+	int ret;
 
 	mtu_base = base;
 
···
 	/* Timer 0 is the free running clocksource */
 	nmdk_clksrc_reset();
 
-	if (clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0",
-			rate, 200, 32, clocksource_mmio_readl_down))
-		pr_err("timer: failed to initialize clock source %s\n",
-		       "mtu_0");
+	ret = clocksource_mmio_init(mtu_base + MTU_VAL(0), "mtu_0",
+				    rate, 200, 32, clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("timer: failed to initialize clock source %s\n", "mtu_0");
+		return ret;
+	}
 
 #ifdef CONFIG_CLKSRC_NOMADIK_MTU_SCHED_CLOCK
 	sched_clock_register(nomadik_read_sched_clock, 32, rate);
···
 	mtu_delay_timer.read_current_timer = &nmdk_timer_read_current_timer;
 	mtu_delay_timer.freq = rate;
 	register_current_timer_delay(&mtu_delay_timer);
+
+	return 0;
 }
 
-static void __init nmdk_timer_of_init(struct device_node *node)
+static int __init nmdk_timer_of_init(struct device_node *node)
 {
 	struct clk *pclk;
 	struct clk *clk;
···
 	int irq;
 
 	base = of_iomap(node, 0);
-	if (!base)
-		panic("Can't remap registers");
+	if (!base) {
+		pr_err("Can't remap registers");
+		return -ENXIO;
+	}
 
 	pclk = of_clk_get_by_name(node, "apb_pclk");
-	if (IS_ERR(pclk))
-		panic("could not get apb_pclk");
+	if (IS_ERR(pclk)) {
+		pr_err("could not get apb_pclk");
+		return PTR_ERR(pclk);
+	}
 
 	clk = of_clk_get_by_name(node, "timclk");
-	if (IS_ERR(clk))
-		panic("could not get timclk");
+	if (IS_ERR(clk)) {
+		pr_err("could not get timclk");
+		return PTR_ERR(clk);
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("Can't parse IRQ");
+	if (irq <= 0) {
+		pr_err("Can't parse IRQ");
+		return -EINVAL;
+	}
 
-	nmdk_timer_init(base, irq, pclk, clk);
+	return nmdk_timer_init(base, irq, pclk, clk);
 }
 CLOCKSOURCE_OF_DECLARE(nomadik_mtu, "st,nomadik-mtu",
 		       nmdk_timer_of_init);

drivers/clocksource/pxa_timer.c

···
 	.dev_id		= &ckevt_pxa_osmr0,
 };
 
-static void __init pxa_timer_common_init(int irq, unsigned long clock_tick_rate)
+static int __init pxa_timer_common_init(int irq, unsigned long clock_tick_rate)
 {
+	int ret;
+
 	timer_writel(0, OIER);
 	timer_writel(OSSR_M0 | OSSR_M1 | OSSR_M2 | OSSR_M3, OSSR);
 
···
 
 	ckevt_pxa_osmr0.cpumask = cpumask_of(0);
 
-	setup_irq(irq, &pxa_ost0_irq);
+	ret = setup_irq(irq, &pxa_ost0_irq);
+	if (ret) {
+		pr_err("Failed to setup irq");
+		return ret;
+	}
 
-	clocksource_mmio_init(timer_base + OSCR, "oscr0", clock_tick_rate, 200,
-			      32, clocksource_mmio_readl_up);
+	ret = clocksource_mmio_init(timer_base + OSCR, "oscr0", clock_tick_rate, 200,
+				    32, clocksource_mmio_readl_up);
+	if (ret) {
+		pr_err("Failed to init clocksource");
+		return ret;
+	}
+
 	clockevents_config_and_register(&ckevt_pxa_osmr0, clock_tick_rate,
 					MIN_OSCR_DELTA * 2, 0x7fffffff);
+
+	return 0;
 }
 
-static void __init pxa_timer_dt_init(struct device_node *np)
+static int __init pxa_timer_dt_init(struct device_node *np)
 {
 	struct clk *clk;
-	int irq;
+	int irq, ret;
 
 	/* timer registers are shared with watchdog timer */
 	timer_base = of_iomap(np, 0);
-	if (!timer_base)
-		panic("%s: unable to map resource\n", np->name);
+	if (!timer_base) {
+		pr_err("%s: unable to map resource\n", np->name);
+		return -ENXIO;
+	}
 
 	clk = of_clk_get(np, 0);
 	if (IS_ERR(clk)) {
 		pr_crit("%s: unable to get clk\n", np->name);
-		return;
+		return PTR_ERR(clk);
 	}
-	clk_prepare_enable(clk);
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_crit("Failed to prepare clock");
+		return ret;
+	}
 
 	/* we are only interested in OS-timer0 irq */
 	irq = irq_of_parse_and_map(np, 0);
 	if (irq <= 0) {
 		pr_crit("%s: unable to parse OS-timer0 irq\n", np->name);
-		return;
+		return -EINVAL;
 	}
 
-	pxa_timer_common_init(irq, clk_get_rate(clk));
+	return pxa_timer_common_init(irq, clk_get_rate(clk));
 }
 CLOCKSOURCE_OF_DECLARE(pxa_timer, "marvell,pxa-timer", pxa_timer_dt_init);
 

drivers/clocksource/qcom-timer.c

···
 	.read_current_timer = msm_read_current_timer,
 };
 
-static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
+static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
 				  bool percpu)
 {
 	struct clocksource *cs = &msm_clocksource;
···
 	sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz);
 	msm_delay_timer.freq = dgt_hz;
 	register_current_timer_delay(&msm_delay_timer);
+
+	return res;
 }
 
-static void __init msm_dt_timer_init(struct device_node *np)
+static int __init msm_dt_timer_init(struct device_node *np)
 {
 	u32 freq;
-	int irq;
+	int irq, ret;
 	struct resource res;
 	u32 percpu_offset;
 	void __iomem *base;
···
 	base = of_iomap(np, 0);
 	if (!base) {
 		pr_err("Failed to map event base\n");
-		return;
+		return -ENXIO;
 	}
 
 	/* We use GPT0 for the clockevent */
 	irq = irq_of_parse_and_map(np, 1);
 	if (irq <= 0) {
 		pr_err("Can't get irq\n");
-		return;
+		return -EINVAL;
 	}
 
 	/* We use CPU0's DGT for the clocksource */
 	if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
 		percpu_offset = 0;
 
-	if (of_address_to_resource(np, 0, &res)) {
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
 		pr_err("Failed to parse DGT resource\n");
-		return;
+		return ret;
 	}
 
 	cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
 	if (!cpu0_base) {
 		pr_err("Failed to map source base\n");
-		return;
+		return -EINVAL;
 	}
 
 	if (of_property_read_u32(np, "clock-frequency", &freq)) {
 		pr_err("Unknown frequency\n");
-		return;
+		return -EINVAL;
 	}
 
 	event_base = base + 0x4;
···
 	freq /= 4;
 	writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
 
-	msm_timer_init(freq, 32, irq, !!percpu_offset);
+	return msm_timer_init(freq, 32, irq, !!percpu_offset);
 }
 CLOCKSOURCE_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);
 CLOCKSOURCE_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);

drivers/clocksource/rockchip_timer.c

···
 
 #define TIMER_LOAD_COUNT0	0x00
 #define TIMER_LOAD_COUNT1	0x04
-#define TIMER_CONTROL_REG	0x10
+#define TIMER_CONTROL_REG3288	0x10
+#define TIMER_CONTROL_REG3399	0x1c
 #define TIMER_INT_STATUS	0x18
 
 #define TIMER_DISABLE		0x0
···
 struct bc_timer {
 	struct clock_event_device ce;
 	void __iomem *base;
+	void __iomem *ctrl;
 	u32 freq;
 };
 
···
 	return rk_timer(ce)->base;
 }
 
+static inline void __iomem *rk_ctrl(struct clock_event_device *ce)
+{
+	return rk_timer(ce)->ctrl;
+}
+
 static inline void rk_timer_disable(struct clock_event_device *ce)
 {
-	writel_relaxed(TIMER_DISABLE, rk_base(ce) + TIMER_CONTROL_REG);
+	writel_relaxed(TIMER_DISABLE, rk_ctrl(ce));
 }
 
 static inline void rk_timer_enable(struct clock_event_device *ce, u32 flags)
 {
 	writel_relaxed(TIMER_ENABLE | TIMER_INT_UNMASK | flags,
-		       rk_base(ce) + TIMER_CONTROL_REG);
+		       rk_ctrl(ce));
 }
 
 static void rk_timer_update_counter(unsigned long cycles,
···
 	return IRQ_HANDLED;
 }
 
-static void __init rk_timer_init(struct device_node *np)
+static int __init rk_timer_init(struct device_node *np, u32 ctrl_reg)
 {
 	struct clock_event_device *ce = &bc_timer.ce;
 	struct clk *timer_clk;
 	struct clk *pclk;
-	int ret, irq;
+	int ret = -EINVAL, irq;
 
 	bc_timer.base = of_iomap(np, 0);
 	if (!bc_timer.base) {
 		pr_err("Failed to get base address for '%s'\n", TIMER_NAME);
-		return;
+		return -ENXIO;
 	}
+	bc_timer.ctrl = bc_timer.base + ctrl_reg;
 
 	pclk = of_clk_get_by_name(np, "pclk");
 	if (IS_ERR(pclk)) {
+		ret = PTR_ERR(pclk);
 		pr_err("Failed to get pclk for '%s'\n", TIMER_NAME);
 		goto out_unmap;
 	}
 
-	if (clk_prepare_enable(pclk)) {
+	ret = clk_prepare_enable(pclk);
+	if (ret) {
 		pr_err("Failed to enable pclk for '%s'\n", TIMER_NAME);
 		goto out_unmap;
 	}
 
 	timer_clk = of_clk_get_by_name(np, "timer");
 	if (IS_ERR(timer_clk)) {
+		ret = PTR_ERR(timer_clk);
 		pr_err("Failed to get timer clock for '%s'\n", TIMER_NAME);
 		goto out_timer_clk;
 	}
 
-	if (clk_prepare_enable(timer_clk)) {
+	ret = clk_prepare_enable(timer_clk);
+	if (ret) {
 		pr_err("Failed to enable timer clock\n");
 		goto out_timer_clk;
 	}
···
 
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
+		ret = -EINVAL;
 		pr_err("Failed to map interrupts for '%s'\n", TIMER_NAME);
 		goto out_irq;
 	}
 
 	ce->name = TIMER_NAME;
-	ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	ce->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
+		       CLOCK_EVT_FEAT_DYNIRQ;
 	ce->set_next_event = rk_timer_set_next_event;
 	ce->set_state_shutdown = rk_timer_shutdown;
 	ce->set_state_periodic = rk_timer_set_periodic;
 	ce->irq = irq;
-	ce->cpumask = cpumask_of(0);
+	ce->cpumask = cpu_possible_mask;
 	ce->rating = 250;
 
 	rk_timer_interrupt_clear(ce);
···
 
 	clockevents_config_and_register(ce, bc_timer.freq, 1, UINT_MAX);
 
-	return;
+	return 0;
 
 out_irq:
 	clk_disable_unprepare(timer_clk);
···
 	clk_disable_unprepare(pclk);
 out_unmap:
 	iounmap(bc_timer.base);
+
+	return ret;
 }
 
-CLOCKSOURCE_OF_DECLARE(rk_timer, "rockchip,rk3288-timer", rk_timer_init);
+static int __init rk3288_timer_init(struct device_node *np)
+{
+	return rk_timer_init(np, TIMER_CONTROL_REG3288);
+}
+
+static int __init rk3399_timer_init(struct device_node *np)
+{
+	return rk_timer_init(np, TIMER_CONTROL_REG3399);
+}
+
+CLOCKSOURCE_OF_DECLARE(rk3288_timer, "rockchip,rk3288-timer",
+		       rk3288_timer_init);
+CLOCKSOURCE_OF_DECLARE(rk3399_timer, "rockchip,rk3399-timer",
+		       rk3399_timer_init);

drivers/clocksource/samsung_pwm_timer.c

···
 
 	spin_lock_irqsave(&samsung_pwm_lock, flags);
 
-	tcon = __raw_readl(pwm.base + REG_TCON);
+	tcon = readl_relaxed(pwm.base + REG_TCON);
 	tcon &= ~TCON_START(channel);
-	__raw_writel(tcon, pwm.base + REG_TCON);
+	writel_relaxed(tcon, pwm.base + REG_TCON);
 
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
···
 
 	spin_lock_irqsave(&samsung_pwm_lock, flags);
 
-	tcon = __raw_readl(pwm.base + REG_TCON);
+	tcon = readl_relaxed(pwm.base + REG_TCON);
 
 	tcon &= ~(TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan));
 	tcon |= TCON_MANUALUPDATE(tcon_chan);
 
-	__raw_writel(tcnt, pwm.base + REG_TCNTB(channel));
-	__raw_writel(tcnt, pwm.base + REG_TCMPB(channel));
-	__raw_writel(tcon, pwm.base + REG_TCON);
+	writel_relaxed(tcnt, pwm.base + REG_TCNTB(channel));
+	writel_relaxed(tcnt, pwm.base + REG_TCMPB(channel));
+	writel_relaxed(tcon, pwm.base + REG_TCON);
 
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
···
 
 	spin_lock_irqsave(&samsung_pwm_lock, flags);
 
-	tcon = __raw_readl(pwm.base + REG_TCON);
+	tcon = readl_relaxed(pwm.base + REG_TCON);
 
 	tcon &= ~TCON_MANUALUPDATE(channel);
 	tcon |= TCON_START(channel);
···
 	else
 		tcon &= ~TCON_AUTORELOAD(channel);
 
-	__raw_writel(tcon, pwm.base + REG_TCON);
+	writel_relaxed(tcon, pwm.base + REG_TCON);
 
 	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
 }
···
 	return samsung_clocksource_read(NULL);
 }
 
-static void __init samsung_clocksource_init(void)
+static int __init samsung_clocksource_init(void)
 {
 	unsigned long pclk;
 	unsigned long clock_rate;
-	int ret;
 
 	pclk = clk_get_rate(pwm.timerclk);
 
···
 						pwm.variant.bits, clock_rate);
 
 	samsung_clocksource.mask = CLOCKSOURCE_MASK(pwm.variant.bits);
-	ret = clocksource_register_hz(&samsung_clocksource, clock_rate);
-	if (ret)
-		panic("samsung_clocksource_timer: can't register clocksource\n");
+	return clocksource_register_hz(&samsung_clocksource, clock_rate);
 }
 
 static void __init samsung_timer_resources(void)
···
 /*
  * PWM master driver
  */
-static void __init _samsung_pwm_clocksource_init(void)
+static int __init _samsung_pwm_clocksource_init(void)
 {
 	u8 mask;
 	int channel;
 
 	mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1);
 	channel = fls(mask) - 1;
-	if (channel < 0)
-		panic("failed to find PWM channel for clocksource");
+	if (channel < 0) {
+		pr_crit("failed to find PWM channel for clocksource");
+		return -EINVAL;
+	}
 	pwm.source_id = channel;
 
 	mask &= ~(1 << channel);
 	channel = fls(mask) - 1;
-	if (channel < 0)
-		panic("failed to find PWM channel for clock event");
+	if (channel < 0) {
+		pr_crit("failed to find PWM channel for clock event");
+		return -EINVAL;
+	}
 	pwm.event_id = channel;
 
 	samsung_timer_resources();
 	samsung_clockevent_init();
-	samsung_clocksource_init();
+
+	return samsung_clocksource_init();
 }
 
 void __init samsung_pwm_clocksource_init(void __iomem *base,
···
 }
 
 #ifdef CONFIG_CLKSRC_OF
-static void __init samsung_pwm_alloc(struct device_node *np,
-				     const struct samsung_pwm_variant *variant)
+static int __init samsung_pwm_alloc(struct device_node *np,
+				    const struct samsung_pwm_variant *variant)
 {
 	struct property *prop;
 	const __be32 *cur;
···
 	pwm.base = of_iomap(np, 0);
 	if (!pwm.base) {
 		pr_err("%s: failed to map PWM registers\n", __func__);
-		return;
+		return -ENXIO;
 	}
 
 	pwm.timerclk = of_clk_get_by_name(np, "timers");
-	if (IS_ERR(pwm.timerclk))
-		panic("failed to get timers clock for timer");
+	if (IS_ERR(pwm.timerclk)) {
+		pr_crit("failed to get timers clock for timer");
+		return PTR_ERR(pwm.timerclk);
+	}
 
-	_samsung_pwm_clocksource_init();
+	return _samsung_pwm_clocksource_init();
 }
 
 static const struct samsung_pwm_variant s3c24xx_variant = {
···
 	.tclk_mask	= (1 << 4),
 };
 
-static void __init s3c2410_pwm_clocksource_init(struct device_node *np)
+static int __init s3c2410_pwm_clocksource_init(struct device_node *np)
 {
-	samsung_pwm_alloc(np, &s3c24xx_variant);
+	return samsung_pwm_alloc(np, &s3c24xx_variant);
 }
 CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);
 
···
 	.tclk_mask	= (1 << 7) | (1 << 6) | (1 << 5),
 };
 
-static void __init s3c64xx_pwm_clocksource_init(struct device_node *np)
+static int __init s3c64xx_pwm_clocksource_init(struct device_node *np)
 {
-	samsung_pwm_alloc(np, &s3c64xx_variant);
+	return samsung_pwm_alloc(np, &s3c64xx_variant);
 }
 CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);
 
···
 	.tclk_mask	= 0,
 };
 
-static void __init s5p64x0_pwm_clocksource_init(struct device_node *np)
+static int __init s5p64x0_pwm_clocksource_init(struct device_node *np)
 {
-	samsung_pwm_alloc(np, &s5p64x0_variant);
+	return samsung_pwm_alloc(np, &s5p64x0_variant);
 }
 CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);
 
···
 	.tclk_mask	= (1 << 5),
 };
 
-static void __init s5p_pwm_clocksource_init(struct device_node *np)
+static int __init s5p_pwm_clocksource_init(struct device_node *np)
 {
-	samsung_pwm_alloc(np, &s5p_variant);
+	return samsung_pwm_alloc(np, &s5p_variant);
 }
 CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
 #endif

drivers/clocksource/sun4i_timer.c

···
 	return ~readl(timer_base + TIMER_CNTVAL_REG(1));
 }
 
-static void __init sun4i_timer_init(struct device_node *node)
+static int __init sun4i_timer_init(struct device_node *node)
 {
 	unsigned long rate = 0;
 	struct clk *clk;
···
 	u32 val;
 
 	timer_base = of_iomap(node, 0);
-	if (!timer_base)
-		panic("Can't map registers");
+	if (!timer_base) {
+		pr_crit("Can't map registers");
+		return -ENXIO;
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("Can't parse IRQ");
+	if (irq <= 0) {
+		pr_crit("Can't parse IRQ");
+		return -EINVAL;
+	}
 
 	clk = of_clk_get(node, 0);
-	if (IS_ERR(clk))
-		panic("Can't get timer clock");
-	clk_prepare_enable(clk);
+	if (IS_ERR(clk)) {
+		pr_crit("Can't get timer clock");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("Failed to prepare clock");
+		return ret;
+	}
 
 	rate = clk_get_rate(clk);
 
···
 	    of_machine_is_compatible("allwinner,sun5i-a10s"))
 		sched_clock_register(sun4i_timer_sched_read, 32, rate);
 
-	clocksource_mmio_init(timer_base + TIMER_CNTVAL_REG(1), node->name,
-			      rate, 350, 32, clocksource_mmio_readl_down);
+	ret = clocksource_mmio_init(timer_base + TIMER_CNTVAL_REG(1), node->name,
+				    rate, 350, 32, clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("Failed to register clocksource");
+		return ret;
+	}
 
 	ticks_per_jiffy = DIV_ROUND_UP(rate, HZ);
 
···
 					TIMER_SYNC_TICKS, 0xffffffff);
 
 	ret = setup_irq(irq, &sun4i_timer_irq);
-	if (ret)
-		pr_warn("failed to setup irq %d\n", irq);
+	if (ret) {
+		pr_err("failed to setup irq %d\n", irq);
+		return ret;
+	}
 
 	/* Enable timer0 interrupt */
 	val = readl(timer_base + TIMER_IRQ_EN_REG);
 	writel(val | TIMER_IRQ_EN(0), timer_base + TIMER_IRQ_EN_REG);
+
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(sun4i, "allwinner,sun4i-a10-timer",
 		       sun4i_timer_init);

drivers/clocksource/tango_xtal.c

···
 	return read_xtal_counter();
 }
 
-static void __init tango_clocksource_init(struct device_node *np)
+static int __init tango_clocksource_init(struct device_node *np)
 {
 	struct clk *clk;
 	int xtal_freq, ret;
···
 	xtal_in_cnt = of_iomap(np, 0);
 	if (xtal_in_cnt == NULL) {
 		pr_err("%s: invalid address\n", np->full_name);
-		return;
+		return -ENXIO;
 	}
 
 	clk = of_clk_get(np, 0);
 	if (IS_ERR(clk)) {
 		pr_err("%s: invalid clock\n", np->full_name);
-		return;
+		return PTR_ERR(clk);
 	}
 
 	xtal_freq = clk_get_rate(clk);
···
 				    32, clocksource_mmio_readl_up);
 	if (ret) {
 		pr_err("%s: registration failed\n", np->full_name);
-		return;
+		return ret;
 	}
 
 	sched_clock_register(read_sched_clock, 32, xtal_freq);
 	register_current_timer_delay(&delay_timer);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(tango, "sigma,tick-counter", tango_clocksource_init);

drivers/clocksource/tegra20_timer.c

···
 	.dev_id		= &tegra_clockevent,
 };
 
-static void __init tegra20_init_timer(struct device_node *np)
+static int __init tegra20_init_timer(struct device_node *np)
 {
 	struct clk *clk;
 	unsigned long rate;
···
 	timer_reg_base = of_iomap(np, 0);
 	if (!timer_reg_base) {
 		pr_err("Can't map timer registers\n");
-		BUG();
+		return -ENXIO;
 	}
 
 	tegra_timer_irq.irq = irq_of_parse_and_map(np, 2);
 	if (tegra_timer_irq.irq <= 0) {
 		pr_err("Failed to map timer IRQ\n");
-		BUG();
+		return -EINVAL;
 	}
 
 	clk = of_clk_get(np, 0);
···
 
 	sched_clock_register(tegra_read_sched_clock, 32, 1000000);
 
-	if (clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
-		"timer_us", 1000000, 300, 32, clocksource_mmio_readl_up)) {
+	ret = clocksource_mmio_init(timer_reg_base + TIMERUS_CNTR_1US,
+				    "timer_us", 1000000, 300, 32,
+				    clocksource_mmio_readl_up);
+	if (ret) {
 		pr_err("Failed to register clocksource\n");
-		BUG();
+		return ret;
 	}
 
 	tegra_delay_timer.read_current_timer =
···
 	ret = setup_irq(tegra_timer_irq.irq, &tegra_timer_irq);
 	if (ret) {
 		pr_err("Failed to register timer IRQ: %d\n", ret);
-		BUG();
+		return ret;
 	}
 
 	tegra_clockevent.cpumask = cpu_all_mask;
 	tegra_clockevent.irq = tegra_timer_irq.irq;
 	clockevents_config_and_register(&tegra_clockevent, 1000000,
 					0x1, 0x1fffffff);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);
 
-static void __init tegra20_init_rtc(struct device_node *np)
+static int __init tegra20_init_rtc(struct device_node *np)
 {
 	struct clk *clk;
 
 	rtc_base = of_iomap(np, 0);
 	if (!rtc_base) {
 		pr_err("Can't map RTC registers");
-		BUG();
+		return -ENXIO;
 	}
 
 	/*
···
 	else
 		clk_prepare_enable(clk);
 
-	register_persistent_clock(NULL, tegra_read_persistent_clock64);
+	return register_persistent_clock(NULL, tegra_read_persistent_clock64);
 }
 CLOCKSOURCE_OF_DECLARE(tegra20_rtc, "nvidia,tegra20-rtc", tegra20_init_rtc);

drivers/clocksource/time-armada-370-xp.c

···
 	writel(timer0_local_ctrl_reg, local_base + TIMER_CTRL_OFF);
 }
 
-struct syscore_ops armada_370_xp_timer_syscore_ops = {
+static struct syscore_ops armada_370_xp_timer_syscore_ops = {
 	.suspend	= armada_370_xp_timer_suspend,
 	.resume		= armada_370_xp_timer_resume,
 };
···
 	.read_current_timer = armada_370_delay_timer_read,
 };
 
-static void __init armada_370_xp_timer_common_init(struct device_node *np)
+static int __init armada_370_xp_timer_common_init(struct device_node *np)
 {
 	u32 clr = 0, set = 0;
 	int res;
 
 	timer_base = of_iomap(np, 0);
-	WARN_ON(!timer_base);
+	if (!timer_base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
+
 	local_base = of_iomap(np, 1);
+	if (!local_base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
 
 	if (timer25Mhz) {
 		set = TIMER0_25MHZ;		
···
 	 */
 	sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk);
 
-	clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
-			      "armada_370_xp_clocksource",
-			      timer_clk, 300, 32, clocksource_mmio_readl_down);
+	res = clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
+				    "armada_370_xp_clocksource",
+				    timer_clk, 300, 32, clocksource_mmio_readl_down);
+	if (res) {
+		pr_err("Failed to initialize clocksource mmio");
+		return res;
+	}
 
 	register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
 
 	armada_370_xp_evt = alloc_percpu(struct clock_event_device);
-
+	if (!armada_370_xp_evt)
+		return -ENOMEM;
 
 	/*
 	 * Setup clockevent timer (interrupt-driven).
···
 				"armada_370_xp_per_cpu_tick",
 				armada_370_xp_evt);
 	/* Immediately configure the timer on the boot CPU */
-	if (!res)
-		armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+	if (res) {
+		pr_err("Failed to request percpu irq");
+		return res;
+	}
+
+	res = armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
+	if (res) {
+		pr_err("Failed to setup timer");
+		return res;
+	}
 
 	register_syscore_ops(&armada_370_xp_timer_syscore_ops);
+	
+	return 0;
 }
 
-static void __init armada_xp_timer_init(struct device_node *np)
+static int __init armada_xp_timer_init(struct device_node *np)
 {
 	struct clk *clk = of_clk_get_by_name(np, "fixed");
+	int ret;
 
-	/* The 25Mhz fixed clock is mandatory, and must always be available */
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
 	timer_clk = clk_get_rate(clk);
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
 CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
 		       armada_xp_timer_init);
 
-static void __init armada_375_timer_init(struct device_node *np)
+static int __init armada_375_timer_init(struct device_node *np)
 {
 	struct clk *clk;
+	int ret;
 
 	clk = of_clk_get_by_name(np, "fixed");
 	if (!IS_ERR(clk)) {
-		clk_prepare_enable(clk);
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
 		timer_clk = clk_get_rate(clk);
 	} else {
 
···
 		clk = of_clk_get(np, 0);
 
 		/* Must have at least a clock */
-		BUG_ON(IS_ERR(clk));
-		clk_prepare_enable(clk);
+		if (IS_ERR(clk)) {
+			pr_err("Failed to get clock");
+			return PTR_ERR(clk);
+		}
+
+		ret = clk_prepare_enable(clk);
+		if (ret)
+			return ret;
+
 		timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
 		timer25Mhz = false;
 	}
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
 CLOCKSOURCE_OF_DECLARE(armada_375, "marvell,armada-375-timer",
 		       armada_375_timer_init);
 
-static void __init armada_370_timer_init(struct device_node *np)
+static int __init armada_370_timer_init(struct device_node *np)
 {
-	struct clk *clk = of_clk_get(np, 0);
+	struct clk *clk;
+	int ret;
 
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
 	timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
 	timer25Mhz = false;
 
-	armada_370_xp_timer_common_init(np);
+	return armada_370_xp_timer_common_init(np);
 }
 CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
 		       armada_370_timer_init);

drivers/clocksource/time-efm32.c

···
 					DIV_ROUND_CLOSEST(rate, 1024),
 					0xf, 0xffff);
 
-	setup_irq(irq, &efm32_clock_event_irq);
+	ret = setup_irq(irq, &efm32_clock_event_irq);
+	if (ret) {
+		pr_err("Failed setup irq");
+		goto err_setup_irq;
+	}
 
 	return 0;
 
+err_setup_irq:
 err_get_irq:
 
 	iounmap(base);
···
  * This function asserts that we have exactly one clocksource and one
  * clock_event_device in the end.
  */
-static void __init efm32_timer_init(struct device_node *np)
+static int __init efm32_timer_init(struct device_node *np)
 {
 	static int has_clocksource, has_clockevent;
-	int ret;
+	int ret = 0;
 
 	if (!has_clocksource) {
 		ret = efm32_clocksource_init(np);
 		if (!ret) {
 			has_clocksource = 1;
-			return;
+			return 0;
 		}
 	}
 
···
 		ret = efm32_clockevent_init(np);
 		if (!ret) {
 			has_clockevent = 1;
-			return;
+			return 0;
 		}
 	}
+
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(efm32compat, "efm32,timer", efm32_timer_init);
 CLOCKSOURCE_OF_DECLARE(efm32, "energymicro,efm32-timer", efm32_timer_init);

drivers/clocksource/time-lpc32xx.c

···
  * This function asserts that we have exactly one clocksource and one
  * clock_event_device in the end.
  */
-static void __init lpc32xx_timer_init(struct device_node *np)
+static int __init lpc32xx_timer_init(struct device_node *np)
 {
 	static int has_clocksource, has_clockevent;
-	int ret;
+	int ret = 0;
 
 	if (!has_clocksource) {
 		ret = lpc32xx_clocksource_init(np);
 		if (!ret) {
 			has_clocksource = 1;
-			return;
+			return 0;
 		}
 	}
 
···
 		ret = lpc32xx_clockevent_init(np);
 		if (!ret) {
 			has_clockevent = 1;
-			return;
+			return 0;
 		}
 	}
+
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(lpc32xx_timer, "nxp,lpc3220-timer", lpc32xx_timer_init);

drivers/clocksource/time-orion.c

···
 	.handler	= orion_clkevt_irq_handler,
 };
 
-static void __init orion_timer_init(struct device_node *np)
+static int __init orion_timer_init(struct device_node *np)
 {
 	struct clk *clk;
-	int irq;
+	int irq, ret;
 
 	/* timer registers are shared with watchdog timer */
 	timer_base = of_iomap(np, 0);
-	if (!timer_base)
-		panic("%s: unable to map resource\n", np->name);
+	if (!timer_base) {
+		pr_err("%s: unable to map resource\n", np->name);
+		return -ENXIO;
+	}
 
 	clk = of_clk_get(np, 0);
-	if (IS_ERR(clk))
-		panic("%s: unable to get clk\n", np->name);
-	clk_prepare_enable(clk);
+	if (IS_ERR(clk)) {
+		pr_err("%s: unable to get clk\n", np->name);
+		return PTR_ERR(clk);
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("Failed to prepare clock");
+		return ret;
+	}
 
 	/* we are only interested in timer1 irq */
 	irq = irq_of_parse_and_map(np, 1);
-	if (irq <= 0)
-		panic("%s: unable to parse timer1 irq\n", np->name);
+	if (irq <= 0) {
+		pr_err("%s: unable to parse timer1 irq\n", np->name);
+		return -EINVAL;
+	}
 
 	/* setup timer0 as free-running clocksource */
 	writel(~0, timer_base + TIMER0_VAL);
···
 	atomic_io_modify(timer_base + TIMER_CTRL,
 		TIMER0_RELOAD_EN | TIMER0_EN,
 		TIMER0_RELOAD_EN | TIMER0_EN);
-	clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
-			      clk_get_rate(clk), 300, 32,
-			      clocksource_mmio_readl_down);
+
+	ret = clocksource_mmio_init(timer_base + TIMER0_VAL, "orion_clocksource",
+				    clk_get_rate(clk), 300, 32,
+				    clocksource_mmio_readl_down);
+	if (ret) {
+		pr_err("Failed to initialize mmio timer");
+		return ret;
+	}
+
 	sched_clock_register(orion_read_sched_clock, 32, clk_get_rate(clk));
 
 	/* setup timer1 as clockevent timer */
-	if (setup_irq(irq, &orion_clkevt_irq))
-		panic("%s: unable to setup irq\n", np->name);
+	ret = setup_irq(irq, &orion_clkevt_irq);
+	if (ret) {
+		pr_err("%s: unable to setup irq\n", np->name);
+		return ret;
+	}
 
 	ticks_per_jiffy = (clk_get_rate(clk) + HZ/2) / HZ;
 	orion_clkevt.cpumask = cpumask_of(0);
 	orion_clkevt.irq = irq;
 	clockevents_config_and_register(&orion_clkevt, clk_get_rate(clk),
 					ORION_ONESHOT_MIN, ORION_ONESHOT_MAX);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(orion_timer, "marvell,orion-timer", orion_timer_init);

drivers/clocksource/time-pistachio.c

···
 		},
 };
 
-static void __init pistachio_clksrc_of_init(struct device_node *node)
+static int __init pistachio_clksrc_of_init(struct device_node *node)
 {
 	struct clk *sys_clk, *fast_clk;
 	struct regmap *periph_regs;
···
 	pcs_gpt.base = of_iomap(node, 0);
 	if (!pcs_gpt.base) {
 		pr_err("cannot iomap\n");
-		return;
+		return -ENXIO;
 	}
 
 	periph_regs = syscon_regmap_lookup_by_phandle(node, "img,cr-periph");
 	if (IS_ERR(periph_regs)) {
 		pr_err("cannot get peripheral regmap (%ld)\n",
 		       PTR_ERR(periph_regs));
-		return;
+		return PTR_ERR(periph_regs);
 	}
 
 	/* Switch to using the fast counter clock */
 	ret = regmap_update_bits(periph_regs, PERIP_TIMER_CONTROL,
 				 0xf, 0x0);
 	if (ret)
-		return;
+		return ret;
 
 	sys_clk = of_clk_get_by_name(node, "sys");
 	if (IS_ERR(sys_clk)) {
 		pr_err("clock get failed (%ld)\n", PTR_ERR(sys_clk));
-		return;
+		return PTR_ERR(sys_clk);
 	}
 
 	fast_clk = of_clk_get_by_name(node, "fast");
 	if (IS_ERR(fast_clk)) {
 		pr_err("clock get failed (%lu)\n", PTR_ERR(fast_clk));
-		return;
+		return PTR_ERR(fast_clk);
 	}
 
 	ret = clk_prepare_enable(sys_clk);
 	if (ret < 0) {
 		pr_err("failed to enable clock (%d)\n", ret);
-		return;
+		return ret;
 	}
 
 	ret = clk_prepare_enable(fast_clk);
 	if (ret < 0) {
 		pr_err("failed to enable clock (%d)\n", ret);
 		clk_disable_unprepare(sys_clk);
-		return;
+		return ret;
 	}
 
 	rate = clk_get_rate(fast_clk);
···
 
 	raw_spin_lock_init(&pcs_gpt.lock);
 	sched_clock_register(pistachio_read_sched_clock, 32, rate);
-	clocksource_register_hz(&pcs_gpt.cs, rate);
+	return clocksource_register_hz(&pcs_gpt.cs, rate);
 }
 CLOCKSOURCE_OF_DECLARE(pistachio_gptimer, "img,pistachio-gptimer",
 		       pistachio_clksrc_of_init);

drivers/clocksource/timer-atlas7.c

···
 	.notifier_call = sirfsoc_cpu_notify,
 };
 
-static void __init sirfsoc_clockevent_init(void)
+static int __init sirfsoc_clockevent_init(void)
 {
 	sirfsoc_clockevent = alloc_percpu(struct clock_event_device);
 	BUG_ON(!sirfsoc_clockevent);
···
 	BUG_ON(register_cpu_notifier(&sirfsoc_cpu_nb));
 
 	/* Immediately configure the timer on the boot CPU */
-	sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
+	return sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent));
 }
 
 /* initialize the kernel jiffy timer source */
-static void __init sirfsoc_atlas7_timer_init(struct device_node *np)
+static int __init sirfsoc_atlas7_timer_init(struct device_node *np)
 {
 	struct clk *clk;
 
···
 
 	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, atlas7_timer_rate));
 
-	sirfsoc_clockevent_init();
+	return sirfsoc_clockevent_init();
 }
 
-static void __init sirfsoc_of_timer_init(struct device_node *np)
+static int __init sirfsoc_of_timer_init(struct device_node *np)
 {
 	sirfsoc_timer_base = of_iomap(np, 0);
-	if (!sirfsoc_timer_base)
-		panic("unable to map timer cpu registers\n");
+	if (!sirfsoc_timer_base) {
+		pr_err("unable to map timer cpu registers\n");
+		return -ENXIO;
+	}
 
 	sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0);
-	if (!sirfsoc_timer_irq.irq)
-		panic("No irq passed for timer0 via DT\n");
+	if (!sirfsoc_timer_irq.irq) {
+		pr_err("No irq passed for timer0 via DT\n");
+		return -EINVAL;
+	}
 
 	sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1);
-	if (!sirfsoc_timer1_irq.irq)
-		panic("No irq passed for timer1 via DT\n");
+	if (!sirfsoc_timer1_irq.irq) {
+		pr_err("No irq passed for timer1 via DT\n");
+		return -EINVAL;
+	}
 
-	sirfsoc_atlas7_timer_init(np);
+	return sirfsoc_atlas7_timer_init(np);
 }
 CLOCKSOURCE_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init);

drivers/clocksource/timer-atmel-pit.c

···
 /*
  * Set up both clocksource and clockevent support.
  */
-static void __init at91sam926x_pit_common_init(struct pit_data *data)
+static int __init at91sam926x_pit_common_init(struct pit_data *data)
 {
 	unsigned long	pit_rate;
 	unsigned	bits;
···
 	data->clksrc.rating = 175;
 	data->clksrc.read = read_pit_clk;
 	data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
-	clocksource_register_hz(&data->clksrc, pit_rate);
+	
+	ret = clocksource_register_hz(&data->clksrc, pit_rate);
+	if (ret) {
+		pr_err("Failed to register clocksource");
+		return ret;
+	}
 
 	/* Set up irq handler */
 	ret = request_irq(data->irq, at91sam926x_pit_interrupt,
 			  IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
 			  "at91_tick", data);
-	if (ret)
-		panic(pr_fmt("Unable to setup IRQ\n"));
+	if (ret) {
+		pr_err("Unable to setup IRQ\n");
+		return ret;
+	}
 
 	/* Set up and register clockevents */
 	data->clkevt.name = "pit";
···
 	data->clkevt.resume = at91sam926x_pit_resume;
 	data->clkevt.suspend = at91sam926x_pit_suspend;
 	clockevents_register_device(&data->clkevt);
+
+	return 0;
 }
 
-static void __init at91sam926x_pit_dt_init(struct device_node *node)
+static int __init at91sam926x_pit_dt_init(struct device_node *node)
 {
 	struct pit_data *data;
 
 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
-		panic(pr_fmt("Unable to allocate memory\n"));
+		return -ENOMEM;
 
 	data->base = of_iomap(node, 0);
-	if (!data->base)
-		panic(pr_fmt("Could not map PIT address\n"));
+	if (!data->base) {
+		pr_err("Could not map PIT address\n");
+		return -ENXIO;
+	}
 
 	data->mck = of_clk_get(node, 0);
 	if (IS_ERR(data->mck))
 		/* Fallback on clkdev for !CCF-based boards */
 		data->mck = clk_get(NULL, "mck");
 
-	if (IS_ERR(data->mck))
-		panic(pr_fmt("Unable to get mck clk\n"));
+	if (IS_ERR(data->mck)) {
+		pr_err("Unable to get mck clk\n");
+		return PTR_ERR(data->mck);
+	}
 
 	/* Get the interrupts property */
 	data->irq = irq_of_parse_and_map(node, 0);
-	if (!data->irq)
-		panic(pr_fmt("Unable to get IRQ from DT\n"));
+	if (!data->irq) {
+		pr_err("Unable to get IRQ from DT\n");
+		return -EINVAL;
+	}
 
-	at91sam926x_pit_common_init(data);
+	return at91sam926x_pit_common_init(data);
 }
 CLOCKSOURCE_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",
 		       at91sam926x_pit_dt_init);

drivers/clocksource/timer-atmel-st.c

···
 /*
  * ST (system timer) module supports both clockevents and clocksource.
  */
-static void __init atmel_st_timer_init(struct device_node *node)
+static int __init atmel_st_timer_init(struct device_node *node)
 {
 	struct clk *sclk;
 	unsigned int sclk_rate, val;
 	int irq, ret;
 
 	regmap_st = syscon_node_to_regmap(node);
-	if (IS_ERR(regmap_st))
-		panic(pr_fmt("Unable to get regmap\n"));
+	if (IS_ERR(regmap_st)) {
+		pr_err("Unable to get regmap\n");
+		return PTR_ERR(regmap_st);
+	}
 
 	/* Disable all timer interrupts, and clear any pending ones */
 	regmap_write(regmap_st, AT91_ST_IDR,
···
 
 	/* Get the interrupts property */
 	irq  = irq_of_parse_and_map(node, 0);
-	if (!irq)
-		panic(pr_fmt("Unable to get IRQ from DT\n"));
+	if (!irq) {
+		pr_err("Unable to get IRQ from DT\n");
+		return -EINVAL;
+	}
 
 	/* Make IRQs happen for the system timer */
 	ret = request_irq(irq, at91rm9200_timer_interrupt,
 			  IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
 			  "at91_tick", regmap_st);
-	if (ret)
-		panic(pr_fmt("Unable to setup IRQ\n"));
+	if (ret) {
+		pr_err("Unable to setup IRQ\n");
+		return ret;
+	}
 
 	sclk = of_clk_get(node, 0);
-	if (IS_ERR(sclk))
-		panic(pr_fmt("Unable to get slow clock\n"));
+	if (IS_ERR(sclk)) {
+		pr_err("Unable to get slow clock\n");
+		return PTR_ERR(sclk);
+	}
 
-	clk_prepare_enable(sclk);
-	if (ret)
-		panic(pr_fmt("Could not enable slow clock\n"));
+	ret = clk_prepare_enable(sclk);
+	if (ret) {
+		pr_err("Could not enable slow clock\n");
+		return ret;
+	}
 
 	sclk_rate = clk_get_rate(sclk);
-	if (!sclk_rate)
-		panic(pr_fmt("Invalid slow clock rate\n"));
+	if (!sclk_rate) {
+		pr_err("Invalid slow clock rate\n");
+		return -EINVAL;
+	}
 	timer_latch = (sclk_rate + HZ / 2) / HZ;
 
 	/* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
···
 					2, AT91_ST_ALMV);
 
 	/* register clocksource */
-	clocksource_register_hz(&clk32k, sclk_rate);
+	return clocksource_register_hz(&clk32k, sclk_rate);
 }
 CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
 		       atmel_st_timer_init);

drivers/clocksource/timer-digicolor.c

···
 	int timer_id; /* one of TIMER_* */
 };
 
-struct digicolor_timer *dc_timer(struct clock_event_device *ce)
+static struct digicolor_timer *dc_timer(struct clock_event_device *ce)
 {
 	return container_of(ce, struct digicolor_timer, ce);
 }
···
 	return ~readl(dc_timer_dev.base + COUNT(TIMER_B));
 }
 
-static void __init digicolor_timer_init(struct device_node *node)
+static int __init digicolor_timer_init(struct device_node *node)
 {
 	unsigned long rate;
 	struct clk *clk;
···
 	dc_timer_dev.base = of_iomap(node, 0);
 	if (!dc_timer_dev.base) {
 		pr_err("Can't map registers");
-		return;
+		return -ENXIO;
 	}
 
 	irq = irq_of_parse_and_map(node, dc_timer_dev.timer_id);
 	if (irq <= 0) {
 		pr_err("Can't parse IRQ");
-		return;
+		return -EINVAL;
 	}
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("Can't get timer clock");
-		return;
+		return PTR_ERR(clk);
 	}
 	clk_prepare_enable(clk);
 	rate = clk_get_rate(clk);
···
 	ret = request_irq(irq, digicolor_timer_interrupt,
 			  IRQF_TIMER | IRQF_IRQPOLL, "digicolor_timerC",
 			  &dc_timer_dev.ce);
-	if (ret)
+	if (ret) {
 		pr_warn("request of timer irq %d failed (%d)\n", irq, ret);
+		return ret;
+	}
 
 	dc_timer_dev.ce.cpumask = cpu_possible_mask;
 	dc_timer_dev.ce.irq = irq;
 
 	clockevents_config_and_register(&dc_timer_dev.ce, rate, 0, 0xffffffff);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(conexant_digicolor, "cnxt,cx92755-timer",
 		       digicolor_timer_init);

drivers/clocksource/timer-imx-gpt.c

···
 	.set_next_event = v2_set_next_event,
 };
 
-static void __init _mxc_timer_init(struct imx_timer *imxtm)
+static int __init _mxc_timer_init(struct imx_timer *imxtm)
 {
+	int ret;
+
 	switch (imxtm->type) {
 	case GPT_TYPE_IMX1:
 		imxtm->gpt = &imx1_gpt_data;
···
 		imxtm->gpt = &imx6dl_gpt_data;
 		break;
 	default:
-		BUG();
+		return -EINVAL;
 	}
 
 	if (IS_ERR(imxtm->clk_per)) {
 		pr_err("i.MX timer: unable to get clk\n");
-		return;
+		return PTR_ERR(imxtm->clk_per);
 	}
 
 	if (!IS_ERR(imxtm->clk_ipg))
···
 	imxtm->gpt->gpt_setup_tctl(imxtm);
 
 	/* init and register the timer to the framework */
-	mxc_clocksource_init(imxtm);
-	mxc_clockevent_init(imxtm);
+	ret = mxc_clocksource_init(imxtm);
+	if (ret)
+		return ret;
+
+	return mxc_clockevent_init(imxtm);
 }
 
 void __init mxc_timer_init(unsigned long pbase, int irq, enum imx_gpt_type type)
···
 	_mxc_timer_init(imxtm);
 }
 
-static void __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
+static int __init mxc_timer_init_dt(struct device_node *np,  enum imx_gpt_type type)
 {
 	struct imx_timer *imxtm;
 	static int initialized;
+	int ret;
 
 	/* Support one instance only */
 	if (initialized)
-		return;
+		return 0;
 
 	imxtm = kzalloc(sizeof(*imxtm), GFP_KERNEL);
-	BUG_ON(!imxtm);
+	if (!imxtm)
+		return -ENOMEM;
 
 	imxtm->base = of_iomap(np, 0);
-	WARN_ON(!imxtm->base);
+	if (!imxtm->base)
+		return -ENXIO;
+
 	imxtm->irq = irq_of_parse_and_map(np, 0);
+	if (imxtm->irq <= 0)
+		return -EINVAL;
 
 	imxtm->clk_ipg = of_clk_get_by_name(np, "ipg");
 
···
 
 	imxtm->type = type;
 
-	_mxc_timer_init(imxtm);
+	ret = _mxc_timer_init(imxtm);
+	if (ret)
+		return ret;
 
 	initialized = 1;
+
+	return 0;
 }
 
-static void __init imx1_timer_init_dt(struct device_node *np)
+static int __init imx1_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX1);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX1);
 }
 
-static void __init imx21_timer_init_dt(struct device_node *np)
+static int __init imx21_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX21);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX21);
 }
 
-static void __init imx31_timer_init_dt(struct device_node *np)
+static int __init imx31_timer_init_dt(struct device_node *np)
 {
 	enum imx_gpt_type type = GPT_TYPE_IMX31;
 
···
 	if (of_machine_is_compatible("fsl,imx6dl"))
 		type = GPT_TYPE_IMX6DL;
 
-	mxc_timer_init_dt(np, type);
+	return mxc_timer_init_dt(np, type);
 }
 
-static void __init imx6dl_timer_init_dt(struct device_node *np)
+static int __init imx6dl_timer_init_dt(struct device_node *np)
 {
-	mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
+	return mxc_timer_init_dt(np, GPT_TYPE_IMX6DL);
 }
 
 CLOCKSOURCE_OF_DECLARE(imx1_timer, "fsl,imx1-gpt", imx1_timer_init_dt);

drivers/clocksource/timer-integrator-ap.c

···
 	return -readl(sched_clk_base + TIMER_VALUE);
 }
 
-static void integrator_clocksource_init(unsigned long inrate,
-					void __iomem *base)
+static int integrator_clocksource_init(unsigned long inrate,
+				       void __iomem *base)
 {
 	u32 ctrl = TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC;
 	unsigned long rate = inrate;
+	int ret;
 
 	if (rate >= 1500000) {
 		rate /= 16;
···
 	writel(0xffff, base + TIMER_LOAD);
 	writel(ctrl, base + TIMER_CTRL);
 
-	clocksource_mmio_init(base + TIMER_VALUE, "timer2",
-			rate, 200, 16, clocksource_mmio_readl_down);
+	ret = clocksource_mmio_init(base + TIMER_VALUE, "timer2",
+				    rate, 200, 16, clocksource_mmio_readl_down);
+	if (ret)
+		return ret;
 
 	sched_clk_base = base;
 	sched_clock_register(integrator_read_sched_clock, 16, rate);
+
+	return 0;
 }
 
 static unsigned long timer_reload;
···
 	.dev_id		= &integrator_clockevent,
 };
 
-static void integrator_clockevent_init(unsigned long inrate,
-				void __iomem *base, int irq)
+static int integrator_clockevent_init(unsigned long inrate,
+				      void __iomem *base, int irq)
 {
 	unsigned long rate = inrate;
 	unsigned int ctrl = 0;
+	int ret;
 
 	clkevt_base = base;
 	/* Calculate and program a divisor */
···
 	timer_reload = rate / HZ;
 	writel(ctrl, clkevt_base + TIMER_CTRL);
 
-	setup_irq(irq, &integrator_timer_irq);
+	ret = setup_irq(irq, &integrator_timer_irq);
+	if (ret)
+		return ret;
+
 	clockevents_config_and_register(&integrator_clockevent,
 					rate,
 					1,
 					0xffffU);
+	return 0;
 }
 
-static void __init integrator_ap_timer_init_of(struct device_node *node)
+static int __init integrator_ap_timer_init_of(struct device_node *node)
 {
 	const char *path;
 	void __iomem *base;
···
 
 	base = of_io_request_and_map(node, 0, "integrator-timer");
 	if (IS_ERR(base))
-		return;
+		return PTR_ERR(base);
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("No clock for %s\n", node->name);
-		return;
+		return PTR_ERR(clk);
 	}
 	clk_prepare_enable(clk);
 	rate = clk_get_rate(clk);
···
 
 	err = of_property_read_string(of_aliases,
 				"arm,timer-primary", &path);
-	if (WARN_ON(err))
-		return;
+	if (err) {
+		pr_warn("Failed to read property");
+		return err;
+	}
+
 	pri_node = of_find_node_by_path(path);
+
 	err = of_property_read_string(of_aliases,
 				"arm,timer-secondary", &path);
-	if (WARN_ON(err))
-		return;
+	if (err) {
+		pr_warn("Failed to read property");		
+		return err;
+	}
+
+
 	sec_node = of_find_node_by_path(path);
 
-	if (node == pri_node) {
+	if (node == pri_node)
 		/* The primary timer lacks IRQ, use as clocksource */
-		integrator_clocksource_init(rate, base);
-		return;
-	}
+		return integrator_clocksource_init(rate, base);
 
 	if (node == sec_node) {
 		/* The secondary timer will drive the clock event */
 		irq = irq_of_parse_and_map(node, 0);
-		integrator_clockevent_init(rate, base, irq);
-		return;
+		return integrator_clockevent_init(rate, base, irq);
 	}
 
 	pr_info("Timer @%p unused\n", base);
 	clk_disable_unprepare(clk);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(integrator_ap_timer, "arm,integrator-timer",

drivers/clocksource/timer-keystone.c

···
 	return 0;
 }
 
-static void __init keystone_timer_init(struct device_node *np)
+static int __init keystone_timer_init(struct device_node *np)
 {
 	struct clock_event_device *event_dev = &timer.event_dev;
 	unsigned long rate;
···
 	irq  = irq_of_parse_and_map(np, 0);
 	if (!irq) {
 		pr_err("%s: failed to map interrupts\n", __func__);
-		return;
+		return -EINVAL;
 	}
 
 	timer.base = of_iomap(np, 0);
 	if (!timer.base) {
 		pr_err("%s: failed to map registers\n", __func__);
-		return;
+		return -ENXIO;
 	}
 
 	clk = of_clk_get(np, 0);
 	if (IS_ERR(clk)) {
 		pr_err("%s: failed to get clock\n", __func__);
 		iounmap(timer.base);
-		return;
+		return PTR_ERR(clk);
 	}
 
 	error = clk_prepare_enable(clk);
···
 	clockevents_config_and_register(event_dev, rate, 1, ULONG_MAX);
 
 	pr_info("keystone timer clock @%lu Hz\n", rate);
-	return;
+	return 0;
 err:
 	clk_put(clk);
 	iounmap(timer.base);
+	return error;
 }
 
 CLOCKSOURCE_OF_DECLARE(keystone_timer, "ti,keystone-timer",
-					keystone_timer_init);
+			   keystone_timer_init);

drivers/clocksource/timer-nps.c

···
 	return (cycle_t)ioread32be(nps_msu_reg_low_addr[cluster]);
 }
 
-static void __init nps_setup_clocksource(struct device_node *node,
-					 struct clk *clk)
+static int __init nps_setup_clocksource(struct device_node *node,
+					struct clk *clk)
 {
 	int ret, cluster;
 
···
 	ret = clk_prepare_enable(clk);
 	if (ret) {
 		pr_err("Couldn't enable parent clock\n");
-		return;
+		return ret;
 	}
 
 	nps_timer_rate = clk_get_rate(clk);
···
 		pr_err("Couldn't register clock source.\n");
 		clk_disable_unprepare(clk);
 	}
+
+	return ret;
 }
 
-static void __init nps_timer_init(struct device_node *node)
+static int __init nps_timer_init(struct device_node *node)
 {
 	struct clk *clk;
 
 	clk = of_clk_get(node, 0);
 	if (IS_ERR(clk)) {
 		pr_err("Can't get timer clock.\n");
-		return;
+		return PTR_ERR(clk);
 	}
 
-	nps_setup_clocksource(node, clk);
+	return nps_setup_clocksource(node, clk);
 }
 
 CLOCKSOURCE_OF_DECLARE(ezchip_nps400_clksrc, "ezchip,nps400-timer",

drivers/clocksource/timer-oxnas-rps.c

···
+/*
+ * drivers/clocksource/timer-oxnas-rps.c
+ *
+ * Copyright (C) 2009 Oxford Semiconductor Ltd
+ * Copyright (C) 2013 Ma Haijun <[e-mail]>
+ * Copyright (C) 2016 Neil Armstrong <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/clockchips.h>
+#include <linux/sched_clock.h>
+
+/* TIMER1 used as tick
+ * TIMER2 used as clocksource
+ */
+
+/* Registers definitions */
+
+#define TIMER_LOAD_REG		0x0
+#define TIMER_CURR_REG		0x4
+#define TIMER_CTRL_REG		0x8
+#define TIMER_CLRINT_REG	0xC
+
+#define TIMER_BITS		24
+
+#define TIMER_MAX_VAL		(BIT(TIMER_BITS) - 1)
+
+#define TIMER_PERIODIC		BIT(6)
+#define TIMER_ENABLE		BIT(7)
+
+#define TIMER_DIV1		(0)
+#define TIMER_DIV16		(1 << 2)
+#define TIMER_DIV256		(2 << 2)
+
+#define TIMER1_REG_OFFSET	0
+#define TIMER2_REG_OFFSET	0x20
+
+/* Clockevent & Clocksource data */
+
+struct oxnas_rps_timer {
+	struct clock_event_device clkevent;
+	void __iomem *clksrc_base;
+	void __iomem *clkevt_base;
+	unsigned long timer_period;
+	unsigned int timer_prescaler;
+	struct clk *clk;
+	int irq;
+};
+
+static irqreturn_t oxnas_rps_timer_irq(int irq, void *dev_id)
+{
+	struct oxnas_rps_timer *rps = dev_id;
+
+	writel_relaxed(0, rps->clkevt_base + TIMER_CLRINT_REG);
+
+	rps->clkevent.event_handler(&rps->clkevent);
+
+	return IRQ_HANDLED;
+}
+
+static void oxnas_rps_timer_config(struct oxnas_rps_timer *rps,
+				   unsigned long period,
+				   unsigned int periodic)
+{
+	uint32_t cfg = rps->timer_prescaler;
+
+	if (period)
+		cfg |= TIMER_ENABLE;
+
+	if (periodic)
+		cfg |= TIMER_PERIODIC;
+
+	writel_relaxed(period, rps->clkevt_base + TIMER_LOAD_REG);
+	writel_relaxed(cfg, rps->clkevt_base + TIMER_CTRL_REG);
+}
+
+static int oxnas_rps_timer_shutdown(struct clock_event_device *evt)
+{
+	struct oxnas_rps_timer *rps =
+		container_of(evt, struct oxnas_rps_timer, clkevent);
+
+	oxnas_rps_timer_config(rps, 0, 0);
+
+	return 0;
+}
+
+static int oxnas_rps_timer_set_periodic(struct clock_event_device *evt)
+{
+	struct oxnas_rps_timer *rps =
+		container_of(evt, struct oxnas_rps_timer, clkevent);
+
+	oxnas_rps_timer_config(rps, rps->timer_period, 1);
+
+	return 0;
+}
+
+static int oxnas_rps_timer_set_oneshot(struct clock_event_device *evt)
+{
+	struct oxnas_rps_timer *rps =
+		container_of(evt, struct oxnas_rps_timer, clkevent);
+
+	oxnas_rps_timer_config(rps, rps->timer_period, 0);
+
+	return 0;
+}
+
+static int oxnas_rps_timer_next_event(unsigned long delta,
+				struct clock_event_device *evt)
+{
+	struct oxnas_rps_timer *rps =
+		container_of(evt, struct oxnas_rps_timer, clkevent);
+
+	oxnas_rps_timer_config(rps, delta, 0);
+
+	return 0;
+}
+
+static int __init oxnas_rps_clockevent_init(struct oxnas_rps_timer *rps)
+{
+	ulong clk_rate = clk_get_rate(rps->clk);
+	ulong timer_rate;
+
+	/* Start with prescaler 1 */
+	rps->timer_prescaler = TIMER_DIV1;
+	rps->timer_period = DIV_ROUND_UP(clk_rate, HZ);
+	timer_rate = clk_rate;
+
+	if (rps->timer_period > TIMER_MAX_VAL) {
+		rps->timer_prescaler = TIMER_DIV16;
+		timer_rate = clk_rate / 16;
+		rps->timer_period = DIV_ROUND_UP(timer_rate, HZ);
+	}
+	if (rps->timer_period > TIMER_MAX_VAL) {
+		rps->timer_prescaler = TIMER_DIV256;
+		timer_rate = clk_rate / 256;
+		rps->timer_period = DIV_ROUND_UP(timer_rate, HZ);
+	}
+
+	rps->clkevent.name = "oxnas-rps";
+	rps->clkevent.features = CLOCK_EVT_FEAT_PERIODIC |
+				 CLOCK_EVT_FEAT_ONESHOT |
+				 CLOCK_EVT_FEAT_DYNIRQ;
+	rps->clkevent.tick_resume = oxnas_rps_timer_shutdown;
+	rps->clkevent.set_state_shutdown = oxnas_rps_timer_shutdown;
+	rps->clkevent.set_state_periodic = oxnas_rps_timer_set_periodic;
+	rps->clkevent.set_state_oneshot = oxnas_rps_timer_set_oneshot;
+	rps->clkevent.set_next_event = oxnas_rps_timer_next_event;
+	rps->clkevent.rating = 200;
+	rps->clkevent.cpumask = cpu_possible_mask;
+	rps->clkevent.irq = rps->irq;
+	clockevents_config_and_register(&rps->clkevent,
+					timer_rate,
+					1,
+					TIMER_MAX_VAL);
+
+	pr_info("Registered clock event rate %luHz prescaler %x period %lu\n",
+			clk_rate,
+			rps->timer_prescaler,
+			rps->timer_period);
+
+	return 0;
+}
+
+/* Clocksource */
+
+static void __iomem *timer_sched_base;
+
+static u64 notrace oxnas_rps_read_sched_clock(void)
+{
+	return ~readl_relaxed(timer_sched_base);
+}
+
+static int __init oxnas_rps_clocksource_init(struct oxnas_rps_timer *rps)
+{
+	ulong clk_rate = clk_get_rate(rps->clk);
+	int ret;
+
+	/* use prescale 16 */
+	clk_rate = clk_rate / 16;
+
+	writel_relaxed(TIMER_MAX_VAL, rps->clksrc_base + TIMER_LOAD_REG);
+	writel_relaxed(TIMER_PERIODIC | TIMER_ENABLE | TIMER_DIV16,
+			rps->clksrc_base + TIMER_CTRL_REG);
+
+	timer_sched_base = rps->clksrc_base + TIMER_CURR_REG;
+	sched_clock_register(oxnas_rps_read_sched_clock,
+			     TIMER_BITS, clk_rate);
+	ret = clocksource_mmio_init(timer_sched_base,
+				    "oxnas_rps_clocksource_timer",
+				    clk_rate, 250, TIMER_BITS,
+				    clocksource_mmio_readl_down);
+	if (WARN_ON(ret)) {
+		pr_err("can't register clocksource\n");
+		return ret;
+	}
+
+	pr_info("Registered clocksource rate %luHz\n", clk_rate);
+
+	return 0;
+}
+
+static int __init oxnas_rps_timer_init(struct device_node *np)
+{
+	struct oxnas_rps_timer *rps;
+	void __iomem *base;
+	int ret;
+
+	rps = kzalloc(sizeof(*rps), GFP_KERNEL);
+	if (!rps)
+		return -ENOMEM;
+
+	rps->clk = of_clk_get(np, 0);
+	if (IS_ERR(rps->clk)) {
+		ret = PTR_ERR(rps->clk);
+		goto err_alloc;
+	}
+
+	ret = clk_prepare_enable(rps->clk);
+	if (ret)
+		goto err_clk;
+
+	base = of_iomap(np, 0);
+	if (!base) {
+		ret = -ENXIO;
+		goto err_clk_prepare;
+	}
+
+	rps->irq = irq_of_parse_and_map(np, 0);
+	if (rps->irq < 0) {
+		ret = -EINVAL;
+		goto err_iomap;
+	}
+
+	rps->clkevt_base = base + TIMER1_REG_OFFSET;
+	rps->clksrc_base = base + TIMER2_REG_OFFSET;
+
+	/* Disable timers */
+	writel_relaxed(0, rps->clkevt_base + TIMER_CTRL_REG);
+	writel_relaxed(0, rps->clksrc_base + TIMER_CTRL_REG);
+	writel_relaxed(0, rps->clkevt_base + TIMER_LOAD_REG);
+	writel_relaxed(0, rps->clksrc_base + TIMER_LOAD_REG);
+	writel_relaxed(0, rps->clkevt_base + TIMER_CLRINT_REG);
+	writel_relaxed(0, rps->clksrc_base + TIMER_CLRINT_REG);
+
+	ret = request_irq(rps->irq, oxnas_rps_timer_irq,
+			  IRQF_TIMER | IRQF_IRQPOLL,
+			  "rps-timer", rps);
+	if (ret)
+		goto err_iomap;
+
+	ret = oxnas_rps_clocksource_init(rps);
+	if (ret)
+		goto err_irqreq;
+
+	ret = oxnas_rps_clockevent_init(rps);
+	if (ret)
+		goto err_irqreq;
+
+	return 0;
+
+err_irqreq:
+	free_irq(rps->irq, rps);
+err_iomap:
+	iounmap(base);
+err_clk_prepare:
+	clk_disable_unprepare(rps->clk);
+err_clk:
+	clk_put(rps->clk);
+err_alloc:
+	kfree(rps);
+
+	return ret;
+}
+
+CLOCKSOURCE_OF_DECLARE(ox810se_rps,
+		       "oxsemi,ox810se-rps-timer", oxnas_rps_timer_init);

drivers/clocksource/timer-prima2.c

···
 #include <linux/of_irq.h>
 #include <linux/of_address.h>
 #include <linux/sched_clock.h>
-#include <asm/mach/time.h>
 
 #define PRIMA2_CLOCK_FREQ 1000000
 
···
 }
 
 /* initialize the kernel jiffy timer source */
-static void __init sirfsoc_prima2_timer_init(struct device_node *np)
+static int __init sirfsoc_prima2_timer_init(struct device_node *np)
 {
 	unsigned long rate;
 	struct clk *clk;
+	int ret;
 
 	clk = of_clk_get(np, 0);
-	BUG_ON(IS_ERR(clk));
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
 
-	BUG_ON(clk_prepare_enable(clk));
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		pr_err("Failed to enable clock");
+		return ret;
+	}
 
 	rate = clk_get_rate(clk);
 
-	BUG_ON(rate < PRIMA2_CLOCK_FREQ);
-	BUG_ON(rate % PRIMA2_CLOCK_FREQ);
+	if (rate < PRIMA2_CLOCK_FREQ || rate % PRIMA2_CLOCK_FREQ) {
+		pr_err("Invalid clock rate");
+		return -EINVAL;
+	}
 
 	sirfsoc_timer_base = of_iomap(np, 0);
-	if (!sirfsoc_timer_base)
-		panic("unable to map timer cpu registers\n");
+	if (!sirfsoc_timer_base) {
+		pr_err("unable to map timer cpu registers\n");
+		return -ENXIO;
+	}
 
 	sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0);
 
···
 	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
 	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
 
-	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource,
-				       PRIMA2_CLOCK_FREQ));
+	ret = clocksource_register_hz(&sirfsoc_clocksource, PRIMA2_CLOCK_FREQ);
+	if (ret) {
+		pr_err("Failed to register clocksource");
+		return ret;
+	}
 
 	sched_clock_register(sirfsoc_read_sched_clock, 64, PRIMA2_CLOCK_FREQ);
 
-	BUG_ON(setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq));
+	ret = setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq);
+	if (ret) {
+		pr_err("Failed to setup irq");
+		return ret;
+	}
 
 	sirfsoc_clockevent_init();
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(sirfsoc_prima2_timer,
 	"sirf,prima2-tick", sirfsoc_prima2_timer_init);

drivers/clocksource/timer-sp804.c

···
 	writel(0, base + TIMER_CTRL);
 }
 
-void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
+int  __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
 						     const char *name,
 						     struct clk *clk,
 						     int use_sched_clock)
···
 		if (IS_ERR(clk)) {
 			pr_err("sp804: clock not found: %d\n",
 			       (int)PTR_ERR(clk));
-			return;
+			return PTR_ERR(clk);
 		}
 	}
 
 	rate = sp804_get_clock_rate(clk);
-
 	if (rate < 0)
-		return;
+		return -EINVAL;
 
 	/* setup timer 0 as free-running clocksource */
 	writel(0, base + TIMER_CTRL);
···
 		sched_clock_base = base;
 		sched_clock_register(sp804_read, 32, rate);
 	}
+
+	return 0;
 }
 
 
···
 	.dev_id		= &sp804_clockevent,
 };
 
-void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
+int __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
 {
 	struct clock_event_device *evt = &sp804_clockevent;
 	long rate;
···
 	if (IS_ERR(clk)) {
 		pr_err("sp804: %s clock not found: %d\n", name,
 			(int)PTR_ERR(clk));
-		return;
+		return PTR_ERR(clk);
 	}
 
 	rate = sp804_get_clock_rate(clk);
 	if (rate < 0)
-		return;
+		return -EINVAL;
 
 	clkevt_base = base;
 	clkevt_reload = DIV_ROUND_CLOSEST(rate, HZ);
···
 
 	setup_irq(irq, &sp804_timer_irq);
 	clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
+
+	return 0;
 }
 
-static void __init sp804_of_init(struct device_node *np)
+static int __init sp804_of_init(struct device_node *np)
 {
 	static bool initialized = false;
 	void __iomem *base;
-	int irq;
+	int irq, ret = -EINVAL;
 	u32 irq_num = 0;
 	struct clk *clk1, *clk2;
 	const char *name = of_get_property(np, "compatible", NULL);
 
 	base = of_iomap(np, 0);
-	if (WARN_ON(!base))
-		return;
+	if (!base)
+		return -ENXIO;
 
 	/* Ensure timers are disabled */
 	writel(0, base + TIMER_CTRL);
 	writel(0, base + TIMER_2_BASE + TIMER_CTRL);
 
-	if (initialized || !of_device_is_available(np))
+	if (initialized || !of_device_is_available(np)) {
+		ret = -EINVAL;
 		goto err;
+	}
 
 	clk1 = of_clk_get(np, 0);
 	if (IS_ERR(clk1))
···
 
 	of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
 	if (irq_num == 2) {
-		__sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
-		__sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+
+		ret = __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
+		if (ret)
+			goto err;
+
+		ret = __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+		if (ret)
+			goto err;
 	} else {
-		__sp804_clockevents_init(base, irq, clk1 , name);
-		__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
-							 name, clk2, 1);
+
+		ret = __sp804_clockevents_init(base, irq, clk1 , name);
+		if (ret)
+			goto err;
+
+		ret =__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
+							      name, clk2, 1);
+		if (ret)
+			goto err;
 	}
 	initialized = true;
 
-	return;
+	return 0;
 err:
 	iounmap(base);
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(sp804, "arm,sp804", sp804_of_init);
 
-static void __init integrator_cp_of_init(struct device_node *np)
+static int __init integrator_cp_of_init(struct device_node *np)
 {
 	static int init_count = 0;
 	void __iomem *base;
-	int irq;
+	int irq, ret = -EINVAL;
 	const char *name = of_get_property(np, "compatible", NULL);
 	struct clk *clk;
 
 	base = of_iomap(np, 0);
-	if (WARN_ON(!base))
-		return;
+	if (!base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
+
 	clk = of_clk_get(np, 0);
-	if (WARN_ON(IS_ERR(clk)))
-		return;
+	if (IS_ERR(clk)) {
+		pr_err("Failed to get clock");
+		return PTR_ERR(clk);
+	}
 
 	/* Ensure timer is disabled */
 	writel(0, base + TIMER_CTRL);
···
 	if (init_count == 2 || !of_device_is_available(np))
 		goto err;
 
-	if (!init_count)
-		__sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
-	else {
+	if (!init_count) {
+		ret = __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
+		if (ret)
+			goto err;
+	} else {
 		irq = irq_of_parse_and_map(np, 0);
 		if (irq <= 0)
 			goto err;
 
-		__sp804_clockevents_init(base, irq, clk, name);
+		ret = __sp804_clockevents_init(base, irq, clk, name);
+		if (ret)
+			goto err;
 	}
 
 	init_count++;
-	return;
+	return 0;
 err:
 	iounmap(base);
+	return ret;
 }
 CLOCKSOURCE_OF_DECLARE(intcp, "arm,integrator-cp-timer", integrator_cp_of_init);

drivers/clocksource/timer-stm32.c

···
 	},
 };
 
-static void __init stm32_clockevent_init(struct device_node *np)
+static int __init stm32_clockevent_init(struct device_node *np)
 {
 	struct stm32_clock_event_ddata *data = &clock_event_ddata;
 	struct clk *clk;
···
 
 	data->base = of_iomap(np, 0);
 	if (!data->base) {
+		ret = -ENXIO;
 		pr_err("failed to map registers for clockevent\n");
 		goto err_iomap;
 	}
 
 	irq = irq_of_parse_and_map(np, 0);
 	if (!irq) {
+		ret = -EINVAL;
 		pr_err("%s: failed to get irq.\n", np->full_name);
 		goto err_get_irq;
 	}
···
 	pr_info("%s: STM32 clockevent driver initialized (%d bits)\n",
 			np->full_name, bits);
 
-	return;
+	return ret;
 
 err_get_irq:
 	iounmap(data->base);
···
 err_clk_enable:
 	clk_put(clk);
 err_clk_get:
-	return;
+	return ret;
 }
 
 CLOCKSOURCE_OF_DECLARE(stm32, "st,stm32-timer", stm32_clockevent_init);

drivers/clocksource/timer-sun5i.c

···
 	return ret;
 }
 
-static void __init sun5i_timer_init(struct device_node *node)
+static int __init sun5i_timer_init(struct device_node *node)
 {
 	struct reset_control *rstc;
 	void __iomem *timer_base;
 	struct clk *clk;
-	int irq;
+	int irq, ret;
 
 	timer_base = of_io_request_and_map(node, 0, of_node_full_name(node));
-	if (IS_ERR(timer_base))
-		panic("Can't map registers");
+	if (IS_ERR(timer_base)) {
+		pr_err("Can't map registers");
+		return PTR_ERR(timer_base);;
+	}
 
 	irq = irq_of_parse_and_map(node, 0);
-	if (irq <= 0)
-		panic("Can't parse IRQ");
+	if (irq <= 0) {
+		pr_err("Can't parse IRQ");
+		return -EINVAL;
+	}
 
 	clk = of_clk_get(node, 0);
-	if (IS_ERR(clk))
-		panic("Can't get timer clock");
+	if (IS_ERR(clk)) {
+		pr_err("Can't get timer clock");
+		return PTR_ERR(clk);
+	}
 
 	rstc = of_reset_control_get(node, NULL);
 	if (!IS_ERR(rstc))
 		reset_control_deassert(rstc);
 
-	sun5i_setup_clocksource(node, timer_base, clk, irq);
-	sun5i_setup_clockevent(node, timer_base, clk, irq);
+	ret = sun5i_setup_clocksource(node, timer_base, clk, irq);
+	if (ret)
+		return ret;
+
+	return sun5i_setup_clockevent(node, timer_base, clk, irq);
 }
 CLOCKSOURCE_OF_DECLARE(sun5i_a13, "allwinner,sun5i-a13-hstimer",
-		       sun5i_timer_init);
+			   sun5i_timer_init);
 CLOCKSOURCE_OF_DECLARE(sun7i_a20, "allwinner,sun7i-a20-hstimer",
-		       sun5i_timer_init);
+			   sun5i_timer_init);

drivers/clocksource/timer-ti-32k.c

···
 	return ti_32k_read_cycles(&ti_32k_timer.cs);
 }
 
-static void __init ti_32k_timer_init(struct device_node *np)
+static int __init ti_32k_timer_init(struct device_node *np)
 {
 	int ret;
 
 	ti_32k_timer.base = of_iomap(np, 0);
 	if (!ti_32k_timer.base) {
 		pr_err("Can't ioremap 32k timer base\n");
-		return;
+		return -ENXIO;
 	}
 
 	ti_32k_timer.counter = ti_32k_timer.base;
···
 	ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
 	if (ret) {
 		pr_err("32k_counter: can't register clocksource\n");
-		return;
+		return ret;
 	}
 
 	sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
 	pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
 		ti_32k_timer_init);

drivers/clocksource/timer-u300.c

···
 /*
  * This sets up the system timers, clock source and clock event.
  */
-static void __init u300_timer_init_of(struct device_node *np)
+static int __init u300_timer_init_of(struct device_node *np)
 {
 	unsigned int irq;
 	struct clk *clk;
 	unsigned long rate;
+	int ret;
 
 	u300_timer_base = of_iomap(np, 0);
-	if (!u300_timer_base)
-		panic("could not ioremap system timer\n");
+	if (!u300_timer_base) {
+		pr_err("could not ioremap system timer\n");
+		return -ENXIO;
+	}
 
 	/* Get the IRQ for the GP1 timer */
 	irq = irq_of_parse_and_map(np, 2);
-	if (!irq)
-		panic("no IRQ for system timer\n");
+	if (!irq) {
+		pr_err("no IRQ for system timer\n");
+		return -EINVAL;
+	}
 
 	pr_info("U300 GP1 timer @ base: %p, IRQ: %u\n", u300_timer_base, irq);
 
 	/* Clock the interrupt controller */
 	clk = of_clk_get(np, 0);
-	BUG_ON(IS_ERR(clk));
-	clk_prepare_enable(clk);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		return ret;
+
 	rate = clk_get_rate(clk);
 
 	u300_clockevent_data.ticks_per_jiffy = DIV_ROUND_CLOSEST(rate, HZ);
···
 		u300_timer_base + U300_TIMER_APP_RGPT1);
 
 	/* Set up the IRQ handler */
-	setup_irq(irq, &u300_timer_irq);
+	ret = setup_irq(irq, &u300_timer_irq);
+	if (ret)
+		return ret;
 
 	/* Reset the General Purpose timer 2 */
 	writel(U300_TIMER_APP_RGPT2_TIMER_RESET,
···
 		u300_timer_base + U300_TIMER_APP_EGPT2);
 
 	/* Use general purpose timer 2 as clock source */
-	if (clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,
-			"GPT2", rate, 300, 32, clocksource_mmio_readl_up))
+	ret = clocksource_mmio_init(u300_timer_base + U300_TIMER_APP_GPT2CC,
+				    "GPT2", rate, 300, 32, clocksource_mmio_readl_up);
+	if (ret) {
 		pr_err("timer: failed to initialize U300 clock source\n");
+		return ret;
+	}
 
 	/* Configure and register the clockevent */
 	clockevents_config_and_register(&u300_clockevent_data.cevd, rate,
···
 	 * TODO: init and register the rest of the timers too, they can be
 	 * used by hrtimers!
 	 */
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(u300_timer, "stericsson,u300-apptimer",

drivers/clocksource/versatile.c

···
 	return readl(versatile_sys_24mhz);
 }
 
-static void __init versatile_sched_clock_init(struct device_node *node)
+static int __init versatile_sched_clock_init(struct device_node *node)
 {
 	void __iomem *base = of_iomap(node, 0);
 
 	if (!base)
-		return;
+		return -ENXIO;
 
 	versatile_sys_24mhz = base + SYS_24MHZ;
 
 	sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
+
+	return 0;
 }
 CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
 		       versatile_sched_clock_init);

drivers/clocksource/vf_pit_timer.c

···
 	return 0;
 }
 
-static void __init pit_timer_init(struct device_node *np)
+static int __init pit_timer_init(struct device_node *np)
 {
 	struct clk *pit_clk;
 	void __iomem *timer_base;
 	unsigned long clk_rate;
-	int irq;
+	int irq, ret;
 
 	timer_base = of_iomap(np, 0);
-	BUG_ON(!timer_base);
+	if (!timer_base) {
+		pr_err("Failed to iomap");
+		return -ENXIO;
+	}
 
 	/*
 	 * PIT0 and PIT1 can be chained to build a 64-bit timer,
···
 	clkevt_base = timer_base + PITn_OFFSET(3);
 
 	irq = irq_of_parse_and_map(np, 0);
-	BUG_ON(irq <= 0);
+	if (irq <= 0)
+		return -EINVAL;
 
 	pit_clk = of_clk_get(np, 0);
-	BUG_ON(IS_ERR(pit_clk));
+	if (IS_ERR(pit_clk))
+		return PTR_ERR(pit_clk);
 
-	BUG_ON(clk_prepare_enable(pit_clk));
+	ret = clk_prepare_enable(pit_clk);
+	if (ret)
+		return ret;
 
 	clk_rate = clk_get_rate(pit_clk);
 	cycle_per_jiffy = clk_rate / (HZ);
···
 	/* enable the pit module */
 	__raw_writel(~PITMCR_MDIS, timer_base + PITMCR);
 
-	BUG_ON(pit_clocksource_init(clk_rate));
+	ret = pit_clocksource_init(clk_rate);
+	if (ret)
+		return ret;
 
-	pit_clockevent_init(clk_rate, irq);
+	return pit_clockevent_init(clk_rate, irq);
 }
 CLOCKSOURCE_OF_DECLARE(vf610, "fsl,vf610-pit", pit_timer_init);

drivers/clocksource/vt8500_timer.c

···
 	.dev_id  = &clockevent,
 };
 
-static void __init vt8500_timer_init(struct device_node *np)
+static int __init vt8500_timer_init(struct device_node *np)
 {
-	int timer_irq;
+	int timer_irq, ret;
 
 	regbase = of_iomap(np, 0);
 	if (!regbase) {
 		pr_err("%s: Missing iobase description in Device Tree\n",
 								__func__);
-		return;
+		return -ENXIO;
 	}
+
 	timer_irq = irq_of_parse_and_map(np, 0);
 	if (!timer_irq) {
 		pr_err("%s: Missing irq description in Device Tree\n",
 								__func__);
-		return;
+		return -EINVAL;
 	}
 
 	writel(1, regbase + TIMER_CTRL_VAL);
 	writel(0xf, regbase + TIMER_STATUS_VAL);
 	writel(~0, regbase + TIMER_MATCH_VAL);
 
-	if (clocksource_register_hz(&clocksource, VT8500_TIMER_HZ))
+	ret = clocksource_register_hz(&clocksource, VT8500_TIMER_HZ);
+	if (ret) {
 		pr_err("%s: vt8500_timer_init: clocksource_register failed for %s\n",
-					__func__, clocksource.name);
+		       __func__, clocksource.name);
+		return ret;
+	}
 
 	clockevent.cpumask = cpumask_of(0);
 
-	if (setup_irq(timer_irq, &irq))
+	ret = setup_irq(timer_irq, &irq);
+	if (ret) {
 		pr_err("%s: setup_irq failed for %s\n", __func__,
 							clockevent.name);
+		return ret;
+	}
+
 	clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ,
 					MIN_OSCR_DELTA * 2, 0xf0000000);
+
+	return 0;
 }
 
 CLOCKSOURCE_OF_DECLARE(vt8500, "via,vt8500-timer", vt8500_timer_init);

drivers/clocksource/zevio-timer.c

···
 	return ret;
 }
 
-static void __init zevio_timer_init(struct device_node *node)
+static int __init zevio_timer_init(struct device_node *node)
 {
-	BUG_ON(zevio_timer_add(node));
+	return zevio_timer_add(node);
 }
 
 CLOCKSOURCE_OF_DECLARE(zevio_timer, "lsi,zevio-timer", zevio_timer_init);

drivers/cpufreq/powernv-cpufreq.c

···
 	else
 		timer_interval = GPSTATE_TIMER_INTERVAL;
 
-	mod_timer_pinned(&gpstates->timer, jiffies +
-			msecs_to_jiffies(timer_interval));
+	mod_timer(&gpstates->timer, jiffies + msecs_to_jiffies(timer_interval));
 }
 
 /**
···
 	policy->driver_data = gpstates;
 
 	/* initialize timer */
-	init_timer_deferrable(&gpstates->timer);
+	init_timer_pinned_deferrable(&gpstates->timer);
 	gpstates->timer.data = (unsigned long)policy;
 	gpstates->timer.function = gpstate_timer_handler;
 	gpstates->timer.expires = jiffies +

drivers/mmc/host/jz4740_mmc.c

···
 	jz4740_mmc_clock_disable(host);
 	setup_timer(&host->timeout_timer, jz4740_mmc_timeout,
 			(unsigned long)host);
-	/* It is not important when it times out, it just needs to timeout. */
-	set_timer_slack(&host->timeout_timer, HZ);
 
 	host->use_dma = true;
 	if (host->use_dma && jz4740_mmc_acquire_dma_channels(host) != 0)

drivers/net/ethernet/tile/tilepro.c

···
 static void tile_net_schedule_egress_timer(struct tile_net_cpu *info)
 {
 	if (!info->egress_timer_scheduled) {
-		mod_timer_pinned(&info->egress_timer, jiffies + 1);
+		mod_timer(&info->egress_timer, jiffies + 1);
 		info->egress_timer_scheduled = true;
 	}
 }
···
 		BUG();
 
 	/* Initialize the egress timer. */
-	init_timer(&info->egress_timer);
+	init_timer_pinned(&info->egress_timer);
 	info->egress_timer.data = (long)info;
 	info->egress_timer.function = tile_net_handle_egress_timer;
 

drivers/power/bq27xxx_battery.c

···
 
 	bq27xxx_battery_update(di);
 
-	if (poll_interval > 0) {
-		/* The timer does not have to be accurate. */
-		set_timer_slack(&di->work.timer, poll_interval * HZ / 4);
+	if (poll_interval > 0)
 		schedule_delayed_work(&di->work, poll_interval * HZ);
-	}
 }
 
 /*

drivers/tty/metag_da.c

···
 	if (channel >= 0)
 		fetch_data(channel);
 
-	mod_timer_pinned(&poll_timer, jiffies + DA_TTY_POLL);
+	mod_timer(&poll_timer, jiffies + DA_TTY_POLL);
 }
 
 static void add_poll_timer(struct timer_list *poll_timer)
 {
-	setup_timer(poll_timer, dashtty_timer, 0);
+	setup_pinned_timer(poll_timer, dashtty_timer, 0);
 	poll_timer->expires = jiffies + DA_TTY_POLL;
 
 	/*

drivers/tty/mips_ejtag_fdc.c

···
 
 	mips_ejtag_fdc_handle(priv);
 	if (!priv->removing)
-		mod_timer_pinned(&priv->poll_timer, jiffies + FDC_TTY_POLL);
+		mod_timer(&priv->poll_timer, jiffies + FDC_TTY_POLL);
 }
 
 /* TTY Port operations */
···
 		raw_spin_unlock_irq(&priv->lock);
 	} else {
 		/* If we didn't get an usable IRQ, poll instead */
-		setup_timer(&priv->poll_timer, mips_ejtag_fdc_tty_timer,
+		setup_pinned_timer(&priv->poll_timer, mips_ejtag_fdc_tty_timer,
 			    (unsigned long)priv);
 		priv->poll_timer.expires = jiffies + FDC_TTY_POLL;
 		/*

drivers/usb/host/ohci-hcd.c

···
 
 	setup_timer(&ohci->io_watchdog, io_watchdog_func,
 			(unsigned long) ohci);
-	set_timer_slack(&ohci->io_watchdog, msecs_to_jiffies(20));
 
 	ohci->hcca = dma_alloc_coherent (hcd->self.controller,
 			sizeof(*ohci->hcca), &ohci->hcca_dma, GFP_KERNEL);

drivers/usb/host/xhci.c

···
 	xhci->comp_mode_recovery_timer.expires = jiffies +
 			msecs_to_jiffies(COMP_MODE_RCVRY_MSECS);
 
-	set_timer_slack(&xhci->comp_mode_recovery_timer,
-			msecs_to_jiffies(COMP_MODE_RCVRY_MSECS));
 	add_timer(&xhci->comp_mode_recovery_timer);
 	xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
 			"Compliance mode recovery timer initialized");

fs/timerfd.c

···
 	     clockid != CLOCK_BOOTTIME_ALARM))
 		return -EINVAL;
 
+	if (!capable(CAP_WAKE_ALARM) &&
+	    (clockid == CLOCK_REALTIME_ALARM ||
+	     clockid == CLOCK_BOOTTIME_ALARM))
+		return -EPERM;
+
 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
···
 	if (ret)
 		return ret;
 	ctx = f.file->private_data;
+
+	if (!capable(CAP_WAKE_ALARM) && isalarm(ctx)) {
+		fdput(f);
+		return -EPERM;
+	}
 
 	timerfd_setup_cancel(ctx, flags);
 

include/clocksource/timer-sp804.h

···
 
 struct clk;
 
-void __sp804_clocksource_and_sched_clock_init(void __iomem *,
-					      const char *, struct clk *, int);
-void __sp804_clockevents_init(void __iomem *, unsigned int,
-			      struct clk *, const char *);
+int __sp804_clocksource_and_sched_clock_init(void __iomem *,
+					     const char *, struct clk *, int);
+int __sp804_clockevents_init(void __iomem *, unsigned int,
+			     struct clk *, const char *);
 void sp804_timer_disable(void __iomem *);
 
 static inline void sp804_clocksource_init(void __iomem *base, const char *name)

include/linux/alarmtimer.h

···
  * struct alarm - Alarm timer structure
  * @node:	timerqueue node for adding to the event list this value
  *		also includes the expiration time.
- * @period:	Period for recuring alarms
+ * @timer:	hrtimer used to schedule events while running
  * @function:	Function pointer to be executed when the timer fires.
- * @type:	Alarm type (BOOTTIME/REALTIME)
- * @enabled:	Flag that represents if the alarm is set to fire or not
+ * @type:	Alarm type (BOOTTIME/REALTIME).
+ * @state:	Flag that represents if the alarm is set to fire or not.
  * @data:	Internal data value.
  */
 struct alarm {

include/linux/clk.h

···
 	return NULL;
 }
 
+static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+{
+	return NULL;
+}
 #endif
 
 /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */

include/linux/clocksource.h

···
 extern int clocksource_i8253_init(void);
 
 #define CLOCKSOURCE_OF_DECLARE(name, compat, fn) \
-	OF_DECLARE_1(clksrc, name, compat, fn)
+	OF_DECLARE_1_RET(clksrc, name, compat, fn)
 
 #ifdef CONFIG_CLKSRC_PROBE
 extern void clocksource_probe(void);

include/linux/list.h

···
 }
 
 /*
+ * Check whether the node is the only node of the head without
+ * accessing head:
+ */
+static inline bool
+hlist_is_singular_node(struct hlist_node *n, struct hlist_head *h)
+{
+	return !n->next && n->pprev == &h->first;
+}
+
+/*
  * Move a list from one list head to another. Fixup the pprev
  * reference of the first entry if it exists.
  */

include/linux/of.h

···
 #endif
 
 typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
+typedef int (*of_init_fn_1_ret)(struct device_node *);
 typedef void (*of_init_fn_1)(struct device_node *);
 
 #define OF_DECLARE_1(table, name, compat, fn) \
 		_OF_DECLARE(table, name, compat, fn, of_init_fn_1)
+#define OF_DECLARE_1_RET(table, name, compat, fn) \
+		_OF_DECLARE(table, name, compat, fn, of_init_fn_1_ret)
 #define OF_DECLARE_2(table, name, compat, fn) \
 		_OF_DECLARE(table, name, compat, fn, of_init_fn_2)
 

include/linux/time.h

···
 	int tm_yday;
 };
 
-void time_to_tm(time_t totalsecs, int offset, struct tm *result);
+void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
+
+/**
+ * time_to_tm - converts the calendar time to local broken-down time
+ *
+ * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
+ *		Coordinated Universal Time (UTC).
+ * @offset	offset seconds adding to totalsecs.
+ * @result	pointer to struct tm variable to receive broken-down time
+ */
+static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result)
+{
+	time64_to_tm(totalsecs, offset, result);
+}
 
 /**
  * timespec_to_ns - Convert timespec to nanoseconds

include/linux/timer.h

···
 	void			(*function)(unsigned long);
 	unsigned long		data;
 	u32			flags;
-	int			slack;
 
 #ifdef CONFIG_TIMER_STATS
 	int			start_pid;
···
  * workqueue locking issues. It's not meant for executing random crap
  * with interrupts disabled. Abuse is monitored!
  */
-#define TIMER_CPUMASK		0x0007FFFF
-#define TIMER_MIGRATING		0x00080000
+#define TIMER_CPUMASK		0x0003FFFF
+#define TIMER_MIGRATING		0x00040000
 #define TIMER_BASEMASK		(TIMER_CPUMASK | TIMER_MIGRATING)
-#define TIMER_DEFERRABLE	0x00100000
+#define TIMER_DEFERRABLE	0x00080000
+#define TIMER_PINNED		0x00100000
 #define TIMER_IRQSAFE		0x00200000
+#define TIMER_ARRAYSHIFT	22
+#define TIMER_ARRAYMASK		0xFFC00000
 
 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
 		.entry = { .next = TIMER_ENTRY_STATIC },	\
···
 		.expires = (_expires),				\
 		.data = (_data),				\
 		.flags = (_flags),				\
-		.slack = -1,					\
 		__TIMER_LOCKDEP_MAP_INITIALIZER(		\
 			__FILE__ ":" __stringify(__LINE__))	\
 	}
···
 #define TIMER_INITIALIZER(_function, _expires, _data)		\
 	__TIMER_INITIALIZER((_function), (_expires), (_data), 0)
 
+#define TIMER_PINNED_INITIALIZER(_function, _expires, _data)	\
+	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_PINNED)
+
 #define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data)	\
 	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE)
+
+#define TIMER_PINNED_DEFERRED_INITIALIZER(_function, _expires, _data)	\
+	__TIMER_INITIALIZER((_function), (_expires), (_data), TIMER_DEFERRABLE | TIMER_PINNED)
 
 #define DEFINE_TIMER(_name, _function, _expires, _data)		\
 	struct timer_list _name =				\
···
 
 #define init_timer(timer)						\
 	__init_timer((timer), 0)
+#define init_timer_pinned(timer)					\
+	__init_timer((timer), TIMER_PINNED)
 #define init_timer_deferrable(timer)					\
 	__init_timer((timer), TIMER_DEFERRABLE)
+#define init_timer_pinned_deferrable(timer)				\
+	__init_timer((timer), TIMER_DEFERRABLE | TIMER_PINNED)
 #define init_timer_on_stack(timer)					\
 	__init_timer_on_stack((timer), 0)
 
···
 
 #define setup_timer(timer, fn, data)					\
 	__setup_timer((timer), (fn), (data), 0)
+#define setup_pinned_timer(timer, fn, data)				\
+	__setup_timer((timer), (fn), (data), TIMER_PINNED)
 #define setup_deferrable_timer(timer, fn, data)				\
 	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE)
+#define setup_pinned_deferrable_timer(timer, fn, data)			\
+	__setup_timer((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 #define setup_timer_on_stack(timer, fn, data)				\
 	__setup_timer_on_stack((timer), (fn), (data), 0)
+#define setup_pinned_timer_on_stack(timer, fn, data)			\
+	__setup_timer_on_stack((timer), (fn), (data), TIMER_PINNED)
 #define setup_deferrable_timer_on_stack(timer, fn, data)		\
 	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE)
+#define setup_pinned_deferrable_timer_on_stack(timer, fn, data)		\
+	__setup_timer_on_stack((timer), (fn), (data), TIMER_DEFERRABLE | TIMER_PINNED)
 
 /**
  * timer_pending - is a timer pending?
···
 extern int del_timer(struct timer_list * timer);
 extern int mod_timer(struct timer_list *timer, unsigned long expires);
 extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
-extern int mod_timer_pinned(struct timer_list *timer, unsigned long expires);
 
-extern void set_timer_slack(struct timer_list *time, int slack_hz);
-
-#define TIMER_NOT_PINNED	0
-#define TIMER_PINNED		1
 /*
  * The jiffies value which is added to now, when there is no timer
  * in the timer wheel:

kernel/signal.c

···
  *  @ts: upper bound on process time suspension
  */
 int do_sigtimedwait(const sigset_t *which, siginfo_t *info,
-			const struct timespec *ts)
+		    const struct timespec *ts)
 {
+	ktime_t *to = NULL, timeout = { .tv64 = KTIME_MAX };
 	struct task_struct *tsk = current;
-	long timeout = MAX_SCHEDULE_TIMEOUT;
 	sigset_t mask = *which;
-	int sig;
+	int sig, ret = 0;
 
 	if (ts) {
 		if (!timespec_valid(ts))
 			return -EINVAL;
-		timeout = timespec_to_jiffies(ts);
-		/*
-		 * We can be close to the next tick, add another one
-		 * to ensure we will wait at least the time asked for.
-		 */
-		if (ts->tv_sec || ts->tv_nsec)
-			timeout++;
+		timeout = timespec_to_ktime(*ts);
+		to = &timeout;
 	}
 
 	/*
···
 
 	spin_lock_irq(&tsk->sighand->siglock);
 	sig = dequeue_signal(tsk, &mask, info);
-	if (!sig && timeout) {
+	if (!sig && timeout.tv64) {
 		/*
 		 * None ready, temporarily unblock those we're interested
 		 * while we are sleeping in so that we'll be awakened when
···
 		recalc_sigpending();
 		spin_unlock_irq(&tsk->sighand->siglock);
 
-		timeout = freezable_schedule_timeout_interruptible(timeout);
-
+		__set_current_state(TASK_INTERRUPTIBLE);
+		ret = freezable_schedule_hrtimeout_range(to, tsk->timer_slack_ns,
+							 HRTIMER_MODE_REL);
 		spin_lock_irq(&tsk->sighand->siglock);
 		__set_task_blocked(tsk, &tsk->real_blocked);
 		sigemptyset(&tsk->real_blocked);
···
 
 	if (sig)
 		return sig;
-	return timeout ? -EINTR : -EAGAIN;
+	return ret ? -EINTR : -EAGAIN;
 }
 
 /**

kernel/time/alarmtimer.c

···
  * struct alarm_base - Alarm timer bases
  * @lock:		Lock for syncrhonized access to the base
  * @timerqueue:		Timerqueue head managing the list of events
- * @timer: 		hrtimer used to schedule events while running
  * @gettime:		Function to read the time correlating to the base
  * @base_clockid:	clockid for the base
  */

kernel/time/clockevents.c

···
 #endif
 
 #ifdef CONFIG_SYSFS
-struct bus_type clockevents_subsys = {
+static struct bus_type clockevents_subsys = {
 	.name		= "clockevents",
 	.dev_name       = "clockevent",
 };

kernel/time/clocksource.c

···
 	struct list_head *entry = &clocksource_list;
 	struct clocksource *tmp;
 
-	list_for_each_entry(tmp, &clocksource_list, list)
+	list_for_each_entry(tmp, &clocksource_list, list) {
 		/* Keep track of the place, where to insert */
-		if (tmp->rating >= cs->rating)
-			entry = &tmp->list;
+		if (tmp->rating < cs->rating)
+			break;
+		entry = &tmp->list;
+	}
 	list_add(&cs->list, entry);
 }
 

kernel/time/hrtimer.c

···
 #endif
 }
 
-#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
+#ifdef CONFIG_NO_HZ_COMMON
 static inline
 struct hrtimer_cpu_base *get_target_base(struct hrtimer_cpu_base *base,
 					 int pinned)

kernel/time/test_udelay.c

···
 	int allowed_error_ns = usecs * 5;
 
 	for (i = 0; i < iters; ++i) {
-		struct timespec ts1, ts2;
+		s64 kt1, kt2;
 		int time_passed;
 
-		ktime_get_ts(&ts1);
+		kt1 = ktime_get_ns();
 		udelay(usecs);
-		ktime_get_ts(&ts2);
-		time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1);
+		kt2 = ktime_get_ns();
+		time_passed = kt2 - kt1;
 
 		if (i == 0 || time_passed < min)
 			min = time_passed;
···
 	if (usecs > 0 && iters > 0) {
 		return udelay_test_single(s, usecs, iters);
 	} else if (usecs == 0) {
-		struct timespec ts;
+		struct timespec64 ts;
 
-		ktime_get_ts(&ts);
-		seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n",
-				loops_per_jiffy, ts.tv_sec, ts.tv_nsec);
+		ktime_get_ts64(&ts);
+		seq_printf(s, "udelay() test (lpj=%ld kt=%lld.%09ld)\n",
+				loops_per_jiffy, (s64)ts.tv_sec, ts.tv_nsec);
 		seq_puts(s, "usage:\n");
 		seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n");
 		seq_puts(s, "cat " DEBUGFS_FILENAME "\n");

kernel/time/tick-broadcast-hrtimer.c

···
 }
 
 static struct clock_event_device ce_broadcast_hrtimer = {
+	.name			= "bc_hrtimer",
 	.set_state_shutdown	= bc_shutdown,
 	.set_next_ktime		= bc_set_next,
 	.features		= CLOCK_EVT_FEAT_ONESHOT |

kernel/time/tick-internal.h

···
 DECLARE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases);
 
 extern u64 get_next_timer_interrupt(unsigned long basej, u64 basem);
+void timer_clear_idle(void);

kernel/time/tick-sched.c

···
 #include <trace/events/timer.h>
 
 /*
- * Per cpu nohz control structure
+ * Per-CPU nohz control structure
  */
 static DEFINE_PER_CPU(struct tick_sched, tick_cpu_sched);
 
···
 	if (delta.tv64 < tick_period.tv64)
 		return;
 
-	/* Reevalute with jiffies_lock held */
+	/* Reevaluate with jiffies_lock held */
 	write_seqlock(&jiffies_lock);
 
 	delta = ktime_sub(now, last_jiffies_update);
···
 #ifdef CONFIG_NO_HZ_COMMON
 	/*
 	 * Check if the do_timer duty was dropped. We don't care about
-	 * concurrency: This happens only when the cpu in charge went
-	 * into a long sleep. If two cpus happen to assign themself to
+	 * concurrency: This happens only when the CPU in charge went
+	 * into a long sleep. If two CPUs happen to assign themselves to
 	 * this duty, then the jiffies update is still serialized by
 	 * jiffies_lock.
 	 */
···
 /*
  * Re-evaluate the need for the tick as we switch the current task.
  * It might need the tick due to per task/process properties:
- * perf events, posix cpu timers, ...
+ * perf events, posix CPU timers, ...
  */
 void __tick_nohz_task_switch(void)
 {
···
  *
  * In case the sched_tick was stopped on this CPU, we have to check if jiffies
  * must be updated. Otherwise an interrupt handler could use a stale jiffy
- * value. We do this unconditionally on any cpu, as we don't know whether the
- * cpu, which has the update task assigned is in a long sleep.
+ * value. We do this unconditionally on any CPU, as we don't know whether the
+ * CPU, which has the update task assigned is in a long sleep.
  */
 static void tick_nohz_update_jiffies(ktime_t now)
 {
···
 }
 
 /*
- * Updates the per cpu time idle statistics counters
+ * Updates the per-CPU time idle statistics counters
  */
 static void
 update_ts_time_stats(int cpu, struct tick_sched *ts, ktime_t now, u64 *last_update_time)
···
 }
 
 /**
- * get_cpu_idle_time_us - get the total idle time of a cpu
+ * get_cpu_idle_time_us - get the total idle time of a CPU
  * @cpu: CPU number to query
  * @last_update_time: variable to store update time in. Do not update
  * counters if NULL.
  *
- * Return the cummulative idle time (since boot) for a given
+ * Return the cumulative idle time (since boot) for a given
  * CPU, in microseconds.
  *
  * This time is measured via accounting rather than sampling,
···
 EXPORT_SYMBOL_GPL(get_cpu_idle_time_us);
 
 /**
- * get_cpu_iowait_time_us - get the total iowait time of a cpu
+ * get_cpu_iowait_time_us - get the total iowait time of a CPU
  * @cpu: CPU number to query
  * @last_update_time: variable to store update time in. Do not update
  * counters if NULL.
  *
- * Return the cummulative iowait time (since boot) for a given
+ * Return the cumulative iowait time (since boot) for a given
  * CPU, in microseconds.
  *
  * This time is measured via accounting rather than sampling,
···
 	delta = next_tick - basemono;
 	if (delta <= (u64)TICK_NSEC) {
 		tick.tv64 = 0;
+
+		/*
+		 * Tell the timer code that the base is not idle, i.e. undo
+		 * the effect of get_next_timer_interrupt():
+		 */
+		timer_clear_idle();
 		/*
 		 * We've not stopped the tick yet, and there's a timer in the
 		 * next period, so no point in stopping it either, bail.
···
 	}
 
 	/*
-	 * If this cpu is the one which updates jiffies, then give up
-	 * the assignment and let it be taken by the cpu which runs
-	 * the tick timer next, which might be this cpu as well. If we
+	 * If this CPU is the one which updates jiffies, then give up
+	 * the assignment and let it be taken by the CPU which runs
+	 * the tick timer next, which might be this CPU as well. If we
 	 * don't drop this here the jiffies might be stale and
 	 * do_timer() never invoked. Keep track of the fact that it
-	 * was the one which had the do_timer() duty last. If this cpu
+	 * was the one which had the do_timer() duty last. If this CPU
 	 * is the one which had the do_timer() duty last, we limit the
-	 * sleep time to the timekeeping max_deferement value.
+	 * sleep time to the timekeeping max_deferment value.
 	 * Otherwise we can sleep as long as we want.
 	 */
 	delta = timekeeping_max_deferment();
···
 	tick_do_update_jiffies64(now);
 	cpu_load_update_nohz_stop();
 
+	/*
+	 * Clear the timer idle flag, so we avoid IPIs on remote queueing and
+	 * the clock forward checks in the enqueue path:
+	 */
+	timer_clear_idle();
+
 	calc_load_exit_idle();
 	touch_softlockup_watchdog_sched();
 	/*
···
 static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
 {
 	/*
-	 * If this cpu is offline and it is the one which updates
+	 * If this CPU is offline and it is the one which updates
 	 * jiffies, then give up the assignment and let it be taken by
-	 * the cpu which runs the tick timer next. If we don't drop
+	 * the CPU which runs the tick timer next. If we don't drop
 	 * this here the jiffies might be stale and do_timer() never
 	 * invoked.
 	 */
···
 	ktime_t now, expires;
 	int cpu = smp_processor_id();
 
-	now = tick_nohz_start_idle(ts);
-
 	if (can_stop_idle_tick(cpu, ts)) {
 		int was_stopped = ts->tick_stopped;
 
+		now = tick_nohz_start_idle(ts);
 		ts->idle_calls++;
 
 		expires = tick_nohz_stop_sched_tick(ts, now, cpu);
···
 	WARN_ON_ONCE(irqs_disabled());
 
 	/*
- 	 * Update the idle state in the scheduler domain hierarchy
- 	 * when tick_nohz_stop_sched_tick() is called from the idle loop.
- 	 * State will be updated to busy during the first busy tick after
- 	 * exiting idle.
- 	 */
+	 * Update the idle state in the scheduler domain hierarchy
+	 * when tick_nohz_stop_sched_tick() is called from the idle loop.
+	 * State will be updated to busy during the first busy tick after
+	 * exiting idle.
+	 */
 	set_cpu_sd_state_idle();
 
 	local_irq_disable();
···
 	tick_nohz_activate(ts, NOHZ_MODE_LOWRES);
 }
 
-/*
- * When NOHZ is enabled and the tick is stopped, we need to kick the
- * tick timer from irq_enter() so that the jiffies update is kept
- * alive during long running softirqs. That's ugly as hell, but
- * correctness is key even if we need to fix the offending softirq in
- * the first place.
- *
- * Note, this is different to tick_nohz_restart. We just kick the
- * timer and do not touch the other magic bits which need to be done
- * when idle is left.
- */
-static void tick_nohz_kick_tick(struct tick_sched *ts, ktime_t now)
-{
-#if 0
-	/* Switch back to 2.6.27 behaviour */
-	ktime_t delta;
-
-	/*
-	 * Do not touch the tick device, when the next expiry is either
-	 * already reached or less/equal than the tick period.
-	 */
-	delta =	ktime_sub(hrtimer_get_expires(&ts->sched_timer), now);
-	if (delta.tv64 <= tick_period.tv64)
-		return;
-
-	tick_nohz_restart(ts, now);
-#endif
-}
-
 static inline void tick_nohz_irq_enter(void)
 {
 	struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
···
 	now = ktime_get();
 	if (ts->idle_active)
 		tick_nohz_stop_idle(ts, now);
-	if (ts->tick_stopped) {
+	if (ts->tick_stopped)
 		tick_nohz_update_jiffies(now);
-		tick_nohz_kick_tick(ts, now);
-	}
 }
 
 #else
···
 	hrtimer_init(&ts->sched_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 	ts->sched_timer.function = tick_sched_timer;
 
-	/* Get the next period (per cpu) */
+	/* Get the next period (per-CPU) */
 	hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update());
 
 	/* Offset the tick to avert jiffies_lock contention. */

kernel/time/timeconv.c

···
 #define SECS_PER_DAY	(SECS_PER_HOUR * 24)
 
 /**
- * time_to_tm - converts the calendar time to local broken-down time
+ * time64_to_tm - converts the calendar time to local broken-down time
  *
  * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
  *		Coordinated Universal Time (UTC).
  * @offset	offset seconds adding to totalsecs.
  * @result	pointer to struct tm variable to receive broken-down time
  */
-void time_to_tm(time_t totalsecs, int offset, struct tm *result)
+void time64_to_tm(time64_t totalsecs, int offset, struct tm *result)
 {
 	long days, rem, y;
+	int remainder;
 	const unsigned short *ip;
 
-	days = totalsecs / SECS_PER_DAY;
-	rem = totalsecs % SECS_PER_DAY;
+	days = div_s64_rem(totalsecs, SECS_PER_DAY, &remainder);
+	rem = remainder;
 	rem += offset;
 	while (rem < 0) {
 		rem += SECS_PER_DAY;
···
 	result->tm_mon = y;
 	result->tm_mday = days + 1;
 }
-EXPORT_SYMBOL(time_to_tm);
+EXPORT_SYMBOL(time64_to_tm);

kernel/time/timekeeping.c

···
 	* users are removed, this can be killed.
 	*/
 	remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1);
-	tk->tkr_mono.xtime_nsec -= remainder;
-	tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift;
-	tk->ntp_error += remainder << tk->ntp_error_shift;
-	tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift;
+	if (remainder != 0) {
+		tk->tkr_mono.xtime_nsec -= remainder;
+		tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift;
+		tk->ntp_error += remainder << tk->ntp_error_shift;
+		tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift;
+	}
 }
 #else
 #define old_vsyscall_fixup(tk)

kernel/time/timer.c

···
 EXPORT_SYMBOL(jiffies_64);
 
 /*
- * per-CPU timer vector definitions:
+ * The timer wheel has LVL_DEPTH array levels. Each level provides an array of
+ * LVL_SIZE buckets. Each level is driven by its own clock and therefor each
+ * level has a different granularity.
+ *
+ * The level granularity is:		LVL_CLK_DIV ^ lvl
+ * The level clock frequency is:	HZ / (LVL_CLK_DIV ^ level)
+ *
+ * The array level of a newly armed timer depends on the relative expiry
+ * time. The farther the expiry time is away the higher the array level and
+ * therefor the granularity becomes.
+ *
+ * Contrary to the original timer wheel implementation, which aims for 'exact'
+ * expiry of the timers, this implementation removes the need for recascading
+ * the timers into the lower array levels. The previous 'classic' timer wheel
+ * implementation of the kernel already violated the 'exact' expiry by adding
+ * slack to the expiry time to provide batched expiration. The granularity
+ * levels provide implicit batching.
+ *
+ * This is an optimization of the original timer wheel implementation for the
+ * majority of the timer wheel use cases: timeouts. The vast majority of
+ * timeout timers (networking, disk I/O ...) are canceled before expiry. If
+ * the timeout expires it indicates that normal operation is disturbed, so it
+ * does not matter much whether the timeout comes with a slight delay.
+ *
+ * The only exception to this are networking timers with a small expiry
+ * time. They rely on the granularity. Those fit into the first wheel level,
+ * which has HZ granularity.
+ *
+ * We don't have cascading anymore. timers with a expiry time above the
+ * capacity of the last wheel level are force expired at the maximum timeout
+ * value of the last wheel level. From data sampling we know that the maximum
+ * value observed is 5 days (network connection tracking), so this should not
+ * be an issue.
+ *
+ * The currently chosen array constants values are a good compromise between
+ * array size and granularity.
+ *
+ * This results in the following granularity and range levels:
+ *
+ * HZ 1000 steps
+ * Level Offset  Granularity            Range
+ *  0      0         1 ms                0 ms -         63 ms
+ *  1     64         8 ms               64 ms -        511 ms
+ *  2    128        64 ms              512 ms -       4095 ms (512ms - ~4s)
+ *  3    192       512 ms             4096 ms -      32767 ms (~4s - ~32s)
+ *  4    256      4096 ms (~4s)      32768 ms -     262143 ms (~32s - ~4m)
+ *  5    320     32768 ms (~32s)    262144 ms -    2097151 ms (~4m - ~34m)
+ *  6    384    262144 ms (~4m)    2097152 ms -   16777215 ms (~34m - ~4h)
+ *  7    448   2097152 ms (~34m)  16777216 ms -  134217727 ms (~4h - ~1d)
+ *  8    512  16777216 ms (~4h)  134217728 ms - 1073741822 ms (~1d - ~12d)
+ *
+ * HZ  300
+ * Level Offset  Granularity            Range
+ *  0	   0         3 ms                0 ms -        210 ms
+ *  1	  64        26 ms              213 ms -       1703 ms (213ms - ~1s)
+ *  2	 128       213 ms             1706 ms -      13650 ms (~1s - ~13s)
+ *  3	 192      1706 ms (~1s)      13653 ms -     109223 ms (~13s - ~1m)
+ *  4	 256     13653 ms (~13s)    109226 ms -     873810 ms (~1m - ~14m)
+ *  5	 320    109226 ms (~1m)     873813 ms -    6990503 ms (~14m - ~1h)
+ *  6	 384    873813 ms (~14m)   6990506 ms -   55924050 ms (~1h - ~15h)
+ *  7	 448   6990506 ms (~1h)   55924053 ms -  447392423 ms (~15h - ~5d)
+ *  8    512  55924053 ms (~15h) 447392426 ms - 3579139406 ms (~5d - ~41d)
+ *
+ * HZ  250
+ * Level Offset  Granularity            Range
+ *  0	   0         4 ms                0 ms -        255 ms
+ *  1	  64        32 ms              256 ms -       2047 ms (256ms - ~2s)
+ *  2	 128       256 ms             2048 ms -      16383 ms (~2s - ~16s)
+ *  3	 192      2048 ms (~2s)      16384 ms -     131071 ms (~16s - ~2m)
+ *  4	 256     16384 ms (~16s)    131072 ms -    1048575 ms (~2m - ~17m)
+ *  5	 320    131072 ms (~2m)    1048576 ms -    8388607 ms (~17m - ~2h)
+ *  6	 384   1048576 ms (~17m)   8388608 ms -   67108863 ms (~2h - ~18h)
+ *  7	 448   8388608 ms (~2h)   67108864 ms -  536870911 ms (~18h - ~6d)
+ *  8    512  67108864 ms (~18h) 536870912 ms - 4294967288 ms (~6d - ~49d)
+ *
+ * HZ  100
+ * Level Offset  Granularity            Range
+ *  0	   0         10 ms               0 ms -        630 ms
+ *  1	  64         80 ms             640 ms -       5110 ms (640ms - ~5s)
+ *  2	 128        640 ms            5120 ms -      40950 ms (~5s - ~40s)
+ *  3	 192       5120 ms (~5s)     40960 ms -     327670 ms (~40s - ~5m)
+ *  4	 256      40960 ms (~40s)   327680 ms -    2621430 ms (~5m - ~43m)
+ *  5	 320     327680 ms (~5m)   2621440 ms -   20971510 ms (~43m - ~5h)
+ *  6	 384    2621440 ms (~43m) 20971520 ms -  167772150 ms (~5h - ~1d)
+ *  7	 448   20971520 ms (~5h) 167772160 ms - 1342177270 ms (~1d - ~15d)
  */
-#define TVN_BITS (CONFIG_BASE_SMALL ? 4 : 6)
-#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8)
-#define TVN_SIZE (1 << TVN_BITS)
-#define TVR_SIZE (1 << TVR_BITS)
-#define TVN_MASK (TVN_SIZE - 1)
-#define TVR_MASK (TVR_SIZE - 1)
-#define MAX_TVAL ((unsigned long)((1ULL << (TVR_BITS + 4*TVN_BITS)) - 1))
 
-struct tvec {
-	struct hlist_head vec[TVN_SIZE];
-};
+/* Clock divisor for the next level */
+#define LVL_CLK_SHIFT	3
+#define LVL_CLK_DIV	(1UL << LVL_CLK_SHIFT)
+#define LVL_CLK_MASK	(LVL_CLK_DIV - 1)
+#define LVL_SHIFT(n)	((n) * LVL_CLK_SHIFT)
+#define LVL_GRAN(n)	(1UL << LVL_SHIFT(n))
 
-struct tvec_root {
-	struct hlist_head vec[TVR_SIZE];
-};
+/*
+ * The time start value for each level to select the bucket at enqueue
+ * time.
+ */
+#define LVL_START(n)	((LVL_SIZE - 1) << (((n) - 1) * LVL_CLK_SHIFT))
 
-struct tvec_base {
-	spinlock_t lock;
-	struct timer_list *running_timer;
-	unsigned long timer_jiffies;
-	unsigned long next_timer;
-	unsigned long active_timers;
-	unsigned long all_timers;
-	int cpu;
-	bool migration_enabled;
-	bool nohz_active;
-	struct tvec_root tv1;
-	struct tvec tv2;
-	struct tvec tv3;
-	struct tvec tv4;
-	struct tvec tv5;
+/* Size of each clock level */
+#define LVL_BITS	6
+#define LVL_SIZE	(1UL << LVL_BITS)
+#define LVL_MASK	(LVL_SIZE - 1)
+#define LVL_OFFS(n)	((n) * LVL_SIZE)
+
+/* Level depth */
+#if HZ > 100
+# define LVL_DEPTH	9
+# else
+# define LVL_DEPTH	8
+#endif
+
+/* The cutoff (max. capacity of the wheel) */
+#define WHEEL_TIMEOUT_CUTOFF	(LVL_START(LVL_DEPTH))
+#define WHEEL_TIMEOUT_MAX	(WHEEL_TIMEOUT_CUTOFF - LVL_GRAN(LVL_DEPTH - 1))
+
+/*
+ * The resulting wheel size. If NOHZ is configured we allocate two
+ * wheels so we have a separate storage for the deferrable timers.
+ */
+#define WHEEL_SIZE	(LVL_SIZE * LVL_DEPTH)
+
+#ifdef CONFIG_NO_HZ_COMMON
+# define NR_BASES	2
+# define BASE_STD	0
+# define BASE_DEF	1
+#else
+# define NR_BASES	1
+# define BASE_STD	0
+# define BASE_DEF	0
+#endif
+
+struct timer_base {
+	spinlock_t		lock;
+	struct timer_list	*running_timer;
+	unsigned long		clk;
+	unsigned long		next_expiry;
+	unsigned int		cpu;
+	bool			migration_enabled;
+	bool			nohz_active;
+	bool			is_idle;
+	DECLARE_BITMAP(pending_map, WHEEL_SIZE);
+	struct hlist_head	vectors[WHEEL_SIZE];
 } ____cacheline_aligned;
 
-
-static DEFINE_PER_CPU(struct tvec_base, tvec_bases);
+static DEFINE_PER_CPU(struct timer_base, timer_bases[NR_BASES]);
 
 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
 unsigned int sysctl_timer_migration = 1;
···
 	unsigned int cpu;
 
 	/* Avoid the loop, if nothing to update */
-	if (this_cpu_read(tvec_bases.migration_enabled) == on)
+	if (this_cpu_read(timer_bases[BASE_STD].migration_enabled) == on)
 		return;
 
 	for_each_possible_cpu(cpu) {
-		per_cpu(tvec_bases.migration_enabled, cpu) = on;
+		per_cpu(timer_bases[BASE_STD].migration_enabled, cpu) = on;
+		per_cpu(timer_bases[BASE_DEF].migration_enabled, cpu) = on;
 		per_cpu(hrtimer_bases.migration_enabled, cpu) = on;
 		if (!update_nohz)
 			continue;
-		per_cpu(tvec_bases.nohz_active, cpu) = true;
+		per_cpu(timer_bases[BASE_STD].nohz_active, cpu) = true;
+		per_cpu(timer_bases[BASE_DEF].nohz_active, cpu) = true;
 		per_cpu(hrtimer_bases.nohz_active, cpu) = true;
 	}
 }
···
 		timers_update_migration(false);
 	mutex_unlock(&mutex);
 	return ret;
-}
-
-static inline struct tvec_base *get_target_base(struct tvec_base *base,
-						int pinned)
-{
-	if (pinned || !base->migration_enabled)
-		return this_cpu_ptr(&tvec_bases);
-	return per_cpu_ptr(&tvec_bases, get_nohz_timer_target());
-}
-#else
-static inline struct tvec_base *get_target_base(struct tvec_base *base,
-						int pinned)
-{
-	return this_cpu_ptr(&tvec_bases);
 }
 #endif
 
···
 }
 EXPORT_SYMBOL_GPL(round_jiffies_up_relative);
 
-/**
- * set_timer_slack - set the allowed slack for a timer
- * @timer: the timer to be modified
- * @slack_hz: the amount of time (in jiffies) allowed for rounding
- *
- * Set the amount of time, in jiffies, that a certain timer has
- * in terms of slack. By setting this value, the timer subsystem
- * will schedule the actual timer somewhere between
- * the time mod_timer() asks for, and that time plus the slack.
- *
- * By setting the slack to -1, a percentage of the delay is used
- * instead.
- */
-void set_timer_slack(struct timer_list *timer, int slack_hz)
+
+static inline unsigned int timer_get_idx(struct timer_list *timer)
 {
-	timer->slack = slack_hz;
+	return (timer->flags & TIMER_ARRAYMASK) >> TIMER_ARRAYSHIFT;
 }
-EXPORT_SYMBOL_GPL(set_timer_slack);
+
+static inline void timer_set_idx(struct timer_list *timer, unsigned int idx)
+{
+	timer->flags = (timer->flags & ~TIMER_ARRAYMASK) |
+			idx << TIMER_ARRAYSHIFT;
+}
+
+/*
+ * Helper function to calculate the array index for a given expiry
+ * time.
+ */
+static inline unsigned calc_index(unsigned expires, unsigned lvl)
+{
+	expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl);
+	return LVL_OFFS(lvl) + (expires & LVL_MASK);
+}
+
+static int calc_wheel_index(unsigned long expires, unsigned long clk)
+{
+	unsigned long delta = expires - clk;
+	unsigned int idx;
+
+	if (delta < LVL_START(1)) {
+		idx = calc_index(expires, 0);
+	} else if (delta < LVL_START(2)) {
+		idx = calc_index(expires, 1);
+	} else if (delta < LVL_START(3)) {
+		idx = calc_index(expires, 2);
+	} else if (delta < LVL_START(4)) {
+		idx = calc_index(expires, 3);
+	} else if (delta < LVL_START(5)) {
+		idx = calc_index(expires, 4);
+	} else if (delta < LVL_START(6)) {
+		idx = calc_index(expires, 5);
+	} else if (delta < LVL_START(7)) {
+		idx = calc_index(expires, 6);
+	} else if (LVL_DEPTH > 8 && delta < LVL_START(8)) {
+		idx = calc_index(expires, 7);
+	} else if ((long) delta < 0) {
+		idx = clk & LVL_MASK;
+	} else {
+		/*
+		 * Force expire obscene large timeouts to expire at the
+		 * capacity limit of the wheel.
+		 */
+		if (expires >= WHEEL_TIMEOUT_CUTOFF)
+			expires = WHEEL_TIMEOUT_MAX;
+
+		idx = calc_index(expires, LVL_DEPTH - 1);
+	}
+	return idx;
+}
+
+/*
+ * Enqueue the timer into the hash bucket, mark it pending in
+ * the bitmap and store the index in the timer flags.
+ */
+static void enqueue_timer(struct timer_base *base, struct timer_list *timer,
+			  unsigned int idx)
+{
+	hlist_add_head(&timer->entry, base->vectors + idx);
+	__set_bit(idx, base->pending_map);
+	timer_set_idx(timer, idx);
+}
 
 static void
-__internal_add_timer(struct tvec_base *base, struct timer_list *timer)
+__internal_add_timer(struct timer_base *base, struct timer_list *timer)
 {
-	unsigned long expires = timer->expires;
-	unsigned long idx = expires - base->timer_jiffies;
-	struct hlist_head *vec;
+	unsigned int idx;
 
-	if (idx < TVR_SIZE) {
-		int i = expires & TVR_MASK;
-		vec = base->tv1.vec + i;
-	} else if (idx < 1 << (TVR_BITS + TVN_BITS)) {
-		int i = (expires >> TVR_BITS) & TVN_MASK;
-		vec = base->tv2.vec + i;
-	} else if (idx < 1 << (TVR_BITS + 2 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + TVN_BITS)) & TVN_MASK;
-		vec = base->tv3.vec + i;
-	} else if (idx < 1 << (TVR_BITS + 3 * TVN_BITS)) {
-		int i = (expires >> (TVR_BITS + 2 * TVN_BITS)) & TVN_MASK;
-		vec = base->tv4.vec + i;
-	} else if ((signed long) idx < 0) {
-		/*
-		 * Can happen if you add a timer with expires == jiffies,
-		 * or you set a timer to go off in the past
-		 */
-		vec = base->tv1.vec + (base->timer_jiffies & TVR_MASK);
-	} else {
-		int i;
-		/* If the timeout is larger than MAX_TVAL (on 64-bit
-		 * architectures or with CONFIG_BASE_SMALL=1) then we
-		 * use the maximum timeout.
-		 */
-		if (idx > MAX_TVAL) {
-			idx = MAX_TVAL;
-			expires = idx + base->timer_jiffies;
-		}
-		i = (expires >> (TVR_BITS + 3 * TVN_BITS)) & TVN_MASK;
-		vec = base->tv5.vec + i;
-	}
-
-	hlist_add_head(&timer->entry, vec);
+	idx = calc_wheel_index(timer->expires, base->clk);
+	enqueue_timer(base, timer, idx);
 }
 
-static void internal_add_timer(struct tvec_base *base, struct timer_list *timer)
+static void
+trigger_dyntick_cpu(struct timer_base *base, struct timer_list *timer)
 {
-	/* Advance base->jiffies, if the base is empty */
-	if (!base->all_timers++)
-		base->timer_jiffies = jiffies;
-
-	__internal_add_timer(base, timer);
-	/*
-	 * Update base->active_timers and base->next_timer
-	 */
-	if (!(timer->flags & TIMER_DEFERRABLE)) {
-		if (!base->active_timers++ ||
-		    time_before(timer->expires, base->next_timer))
-			base->next_timer = timer->expires;
-	}
+	if (!IS_ENABLED(CONFIG_NO_HZ_COMMON) || !base->nohz_active)
+		return;
 
 	/*
-	 * Check whether the other CPU is in dynticks mode and needs
-	 * to be triggered to reevaluate the timer wheel.
-	 * We are protected against the other CPU fiddling
-	 * with the timer by holding the timer base lock. This also
-	 * makes sure that a CPU on the way to stop its tick can not
-	 * evaluate the timer wheel.
-	 *
-	 * Spare the IPI for deferrable timers on idle targets though.
-	 * The next busy ticks will take care of it. Except full dynticks
-	 * require special care against races with idle_cpu(), lets deal
-	 * with that later.
+	 * TODO: This wants some optimizing similar to the code below, but we
+	 * will do that when we switch from push to pull for deferrable timers.
 	 */
-	if (base->nohz_active) {
-		if (!(timer->flags & TIMER_DEFERRABLE) ||
-		    tick_nohz_full_cpu(base->cpu))
+	if (timer->flags & TIMER_DEFERRABLE) {
+		if (tick_nohz_full_cpu(base->cpu))
 			wake_up_nohz_cpu(base->cpu);
+		return;
 	}
+
+	/*
+	 * We might have to IPI the remote CPU if the base is idle and the
+	 * timer is not deferrable. If the other CPU is on the way to idle
+	 * then it can't set base->is_idle as we hold the base lock:
+	 */
+	if (!base->is_idle)
+		return;
+
+	/* Check whether this is the new first expiring timer: */
+	if (time_after_eq(timer->expires, base->next_expiry))
+		return;
+
+	/*
+	 * Set the next expiry time and kick the CPU so it can reevaluate the
+	 * wheel:
+	 */
+	base->next_expiry = timer->expires;
+		wake_up_nohz_cpu(base->cpu);
+}
+
+static void
+internal_add_timer(struct timer_base *base, struct timer_list *timer)
+{
+	__internal_add_timer(base, timer);
+	trigger_dyntick_cpu(base, timer);
 }
 
 #ifdef CONFIG_TIMER_STATS
···
 {
 	timer->entry.pprev = NULL;
 	timer->flags = flags | raw_smp_processor_id();
-	timer->slack = -1;
 #ifdef CONFIG_TIMER_STATS
 	timer->start_site = NULL;
 	timer->start_pid = -1;
···
 	entry->next = LIST_POISON2;
 }
 
-static inline void
-detach_expired_timer(struct timer_list *timer, struct tvec_base *base)
-{
-	detach_timer(timer, true);
-	if (!(timer->flags & TIMER_DEFERRABLE))
-		base->active_timers--;
-	base->all_timers--;
-}
-
-static int detach_if_pending(struct timer_list *timer, struct tvec_base *base,
+static int detach_if_pending(struct timer_list *timer, struct timer_base *base,
 			     bool clear_pending)
 {
+	unsigned idx = timer_get_idx(timer);
+
 	if (!timer_pending(timer))
 		return 0;
 
+	if (hlist_is_singular_node(&timer->entry, base->vectors + idx))
+		__clear_bit(idx, base->pending_map);
+
 	detach_timer(timer, clear_pending);
-	if (!(timer->flags & TIMER_DEFERRABLE)) {
-		base->active_timers--;
-		if (timer->expires == base->next_timer)
-			base->next_timer = base->timer_jiffies;
-	}
-	/* If this was the last timer, advance base->jiffies */
-	if (!--base->all_timers)
-		base->timer_jiffies = jiffies;
 	return 1;
 }
 
+static inline struct timer_base *get_timer_cpu_base(u32 tflags, u32 cpu)
+{
+	struct timer_base *base = per_cpu_ptr(&timer_bases[BASE_STD], cpu);
+
+	/*
+	 * If the timer is deferrable and nohz is active then we need to use
+	 * the deferrable base.
+	 */
+	if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active &&
+	    (tflags & TIMER_DEFERRABLE))
+		base = per_cpu_ptr(&timer_bases[BASE_DEF], cpu);
+	return base;
+}
+
+static inline struct timer_base *get_timer_this_cpu_base(u32 tflags)
+{
+	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
+
+	/*
+	 * If the timer is deferrable and nohz is active then we need to use
+	 * the deferrable base.
+	 */
+	if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active &&
+	    (tflags & TIMER_DEFERRABLE))
+		base = this_cpu_ptr(&timer_bases[BASE_DEF]);
+	return base;
+}
+
+static inline struct timer_base *get_timer_base(u32 tflags)
+{
+	return get_timer_cpu_base(tflags, tflags & TIMER_CPUMASK);
+}
+
+#ifdef CONFIG_NO_HZ_COMMON
+static inline struct timer_base *
+__get_target_base(struct timer_base *base, unsigned tflags)
+{
+#ifdef CONFIG_SMP
+	if ((tflags & TIMER_PINNED) || !base->migration_enabled)
+		return get_timer_this_cpu_base(tflags);
+	return get_timer_cpu_base(tflags, get_nohz_timer_target());
+#else
+	return get_timer_this_cpu_base(tflags);
+#endif
+}
+
+static inline void forward_timer_base(struct timer_base *base)
+{
+	/*
+	 * We only forward the base when it's idle and we have a delta between
+	 * base clock and jiffies.
+	 */
+	if (!base->is_idle || (long) (jiffies - base->clk) < 2)
+		return;
+
+	/*
+	 * If the next expiry value is > jiffies, then we fast forward to
+	 * jiffies otherwise we forward to the next expiry value.
+	 */
+	if (time_after(base->next_expiry, jiffies))
+		base->clk = jiffies;
+	else
+		base->clk = base->next_expiry;
+}
+#else
+static inline struct timer_base *
+__get_target_base(struct timer_base *base, unsigned tflags)
+{
+	return get_timer_this_cpu_base(tflags);
+}
+
+static inline void forward_timer_base(struct timer_base *base) { }
+#endif
+
+static inline struct timer_base *
+get_target_base(struct timer_base *base, unsigned tflags)
+{
+	struct timer_base *target = __get_target_base(base, tflags);
+
+	forward_timer_base(target);
+	return target;
+}
+
 /*
- * We are using hashed locking: holding per_cpu(tvec_bases).lock
- * means that all timers which are tied to this base via timer->base are
- * locked, and the base itself is locked too.
+ * We are using hashed locking: Holding per_cpu(timer_bases[x]).lock means
+ * that all timers which are tied to this base are locked, and the base itself
+ * is locked too.
  *
  * So __run_timers/migrate_timers can safely modify all timers which could
- * be found on ->tvX lists.
+ * be found in the base->vectors array.
  *
- * When the timer's base is locked and removed from the list, the
- * TIMER_MIGRATING flag is set, FIXME
+ * When a timer is migrating then the TIMER_MIGRATING flag is set and we need
+ * to wait until the migration is done.
  */
-static struct tvec_base *lock_timer_base(struct timer_list *timer,
-					unsigned long *flags)
+static struct timer_base *lock_timer_base(struct timer_list *timer,
+					  unsigned long *flags)
 	__acquires(timer->base->lock)
 {
 	for (;;) {
+		struct timer_base *base;
 		u32 tf = timer->flags;
-		struct tvec_base *base;
 
 		if (!(tf & TIMER_MIGRATING)) {
-			base = per_cpu_ptr(&tvec_bases, tf & TIMER_CPUMASK);
+			base = get_timer_base(tf);
 			spin_lock_irqsave(&base->lock, *flags);
 			if (timer->flags == tf)
 				return base;
···
 }
 
 static inline int
-__mod_timer(struct timer_list *timer, unsigned long expires,
-	    bool pending_only, int pinned)
+__mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
 {
-	struct tvec_base *base, *new_base;
-	unsigned long flags;
+	struct timer_base *base, *new_base;
+	unsigned int idx = UINT_MAX;
+	unsigned long clk = 0, flags;
 	int ret = 0;
+
+	/*
+	 * This is a common optimization triggered by the networking code - if
+	 * the timer is re-modified to have the same timeout or ends up in the
+	 * same array bucket then just return:
+	 */
+	if (timer_pending(timer)) {
+		if (timer->expires == expires)
+			return 1;
+		/*
+		 * Take the current timer_jiffies of base, but without holding
+		 * the lock!
+		 */
+		base = get_timer_base(timer->flags);
+		clk = base->clk;
+
+		idx = calc_wheel_index(expires, clk);
+
+		/*
+		 * Retrieve and compare the array index of the pending
+		 * timer. If it matches set the expiry to the new value so a
+		 * subsequent call will exit in the expires check above.
+		 */
+		if (idx == timer_get_idx(timer)) {
+			timer->expires = expires;
+			return 1;
+		}
+	}
 
 	timer_stats_timer_set_start_info(timer);
 	BUG_ON(!timer->function);
···
 
 	debug_activate(timer, expires);
 
-	new_base = get_target_base(base, pinned);
+	new_base = get_target_base(base, timer->flags);
 
 	if (base != new_base) {
 		/*
-		 * We are trying to schedule the timer on the local CPU.
+		 * We are trying to schedule the timer on the new base.
 		 * However we can't change timer's base while it is running,
 		 * otherwise del_timer_sync() can't detect that the timer's
-		 * handler yet has not finished. This also guarantees that
-		 * the timer is serialized wrt itself.
+		 * handler yet has not finished. This also guarantees that the
+		 * timer is serialized wrt itself.
 		 */
 		if (likely(base->running_timer != timer)) {
 			/* See the comment in lock_timer_base() */
···
 	}
 
 	timer->expires = expires;
-	internal_add_timer(base, timer);
+	/*
+	 * If 'idx' was calculated above and the base time did not advance
+	 * between calculating 'idx' and taking the lock, only enqueue_timer()
+	 * and trigger_dyntick_cpu() is required. Otherwise we need to
+	 * (re)calculate the wheel index via internal_add_timer().
+	 */
+	if (idx != UINT_MAX && clk == base->clk) {
+		enqueue_timer(base, timer, idx);
+		trigger_dyntick_cpu(base, timer);
+	} else {
+		internal_add_timer(base, timer);
+	}
 
 out_unlock:
 	spin_unlock_irqrestore(&base->lock, flags);
···
  */
 int mod_timer_pending(struct timer_list *timer, unsigned long expires)
 {
-	return __mod_timer(timer, expires, true, TIMER_NOT_PINNED);
+	return __mod_timer(timer, expires, true);
 }
 EXPORT_SYMBOL(mod_timer_pending);
-
-/*
- * Decide where to put the timer while taking the slack into account
- *
- * Algorithm:
- *   1) calculate the maximum (absolute) time
- *   2) calculate the highest bit where the expires and new max are different
- *   3) use this bit to make a mask
- *   4) use the bitmask to round down the maximum time, so that all last
- *      bits are zeros
- */
-static inline
-unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
-{
-	unsigned long expires_limit, mask;
-	int bit;
-
-	if (timer->slack >= 0) {
-		expires_limit = expires + timer->slack;
-	} else {
-		long delta = expires - jiffies;
-
-		if (delta < 256)
-			return expires;
-
-		expires_limit = expires + delta / 256;
-	}
-	mask = expires ^ expires_limit;
-	if (mask == 0)
-		return expires;
-
-	bit = __fls(mask);
-
-	mask = (1UL << bit) - 1;
-
-	expires_limit = expires_limit & ~(mask);
-
-	return expires_limit;
-}
 
 /**
  * mod_timer - modify a timer's timeout
···
  */
 int mod_timer(struct timer_list *timer, unsigned long expires)
 {
-	expires = apply_slack(timer, expires);
-
-	/*
-	 * This is a common optimization triggered by the
-	 * networking code - if the timer is re-modified
-	 * to be the same thing then just return:
-	 */
-	if (timer_pending(timer) && timer->expires == expires)
-		return 1;
-
-	return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
+	return __mod_timer(timer, expires, false);
 }
 EXPORT_SYMBOL(mod_timer);
-
-/**
- * mod_timer_pinned - modify a timer's timeout
- * @timer: the timer to be modified
- * @expires: new timeout in jiffies
- *
- * mod_timer_pinned() is a way to update the expire field of an
- * active timer (if the timer is inactive it will be activated)
- * and to ensure that the timer is scheduled on the current CPU.
- *
- * Note that this does not prevent the timer from being migrated
- * when the current CPU goes offline.  If this is a problem for
- * you, use CPU-hotplug notifiers to handle it correctly, for
- * example, cancelling the timer when the corresponding CPU goes
- * offline.
- *
- * mod_timer_pinned(timer, expires) is equivalent to:
- *
- *     del_timer(timer); timer->expires = expires; add_timer(timer);
- */
-int mod_timer_pinned(struct timer_list *timer, unsigned long expires)
-{
-	if (timer->expires == expires && timer_pending(timer))
-		return 1;
-
-	return __mod_timer(timer, expires, false, TIMER_PINNED);
-}
-EXPORT_SYMBOL(mod_timer_pinned);
 
 /**
  * add_timer - start a timer
···
  */
 void add_timer_on(struct timer_list *timer, int cpu)
 {
-	struct tvec_base *new_base = per_cpu_ptr(&tvec_bases, cpu);
-	struct tvec_base *base;
+	struct timer_base *new_base, *base;
 	unsigned long flags;
 
 	timer_stats_timer_set_start_info(timer);
 	BUG_ON(timer_pending(timer) || !timer->function);
+
+	new_base = get_timer_cpu_base(timer->flags, cpu);
 
 	/*
 	 * If @timer was on a different CPU, it should be migrated with the
···
  */
 int del_timer(struct timer_list *timer)
 {
-	struct tvec_base *base;
+	struct timer_base *base;
 	unsigned long flags;
 	int ret = 0;
 
···
  */
 int try_to_del_timer_sync(struct timer_list *timer)
 {
-	struct tvec_base *base;
+	struct timer_base *base;
 	unsigned long flags;
 	int ret = -1;
 
···
 EXPORT_SYMBOL(del_timer_sync);
 #endif
 
-static int cascade(struct tvec_base *base, struct tvec *tv, int index)
-{
-	/* cascade all the timers from tv up one level */
-	struct timer_list *timer;
-	struct hlist_node *tmp;
-	struct hlist_head tv_list;
-
-	hlist_move_list(tv->vec + index, &tv_list);
-
-	/*
-	 * We are removing _all_ timers from the list, so we
-	 * don't have to detach them individually.
-	 */
-	hlist_for_each_entry_safe(timer, tmp, &tv_list, entry) {
-		/* No accounting, while moving them */
-		__internal_add_timer(base, timer);
-	}
-
-	return index;
-}
-
 static void call_timer_fn(struct timer_list *timer, void (*fn)(unsigned long),
 			  unsigned long data)
 {
···
 	}
 }
 
-#define INDEX(N) ((base->timer_jiffies >> (TVR_BITS + (N) * TVN_BITS)) & TVN_MASK)
-
-/**
- * __run_timers - run all expired timers (if any) on this CPU.
- * @base: the timer vector to be processed.
- *
- * This function cascades all vectors and executes all expired timer
- * vectors.
- */
-static inline void __run_timers(struct tvec_base *base)
+static void expire_timers(struct timer_base *base, struct hlist_head *head)
 {
-	struct timer_list *timer;
+	while (!hlist_empty(head)) {
+		struct timer_list *timer;
+		void (*fn)(unsigned long);
+		unsigned long data;
 
-	spin_lock_irq(&base->lock);
+		timer = hlist_entry(head->first, struct timer_list, entry);
+		timer_stats_account_timer(timer);
 
-	while (time_after_eq(jiffies, base->timer_jiffies)) {
-		struct hlist_head work_list;
-		struct hlist_head *head = &work_list;
-		int index;
+		base->running_timer = timer;
+		detach_timer(timer, true);
 
-		if (!base->all_timers) {
-			base->timer_jiffies = jiffies;
-			break;
-		}
+		fn = timer->function;
+		data = timer->data;
 
-		index = base->timer_jiffies & TVR_MASK;
-
-		/*
-		 * Cascade timers:
-		 */
-		if (!index &&
-			(!cascade(base, &base->tv2, INDEX(0))) &&
-				(!cascade(base, &base->tv3, INDEX(1))) &&
-					!cascade(base, &base->tv4, INDEX(2)))
-			cascade(base, &base->tv5, INDEX(3));
-		++base->timer_jiffies;
-		hlist_move_list(base->tv1.vec + index, head);
-		while (!hlist_empty(head)) {
-			void (*fn)(unsigned long);
-			unsigned long data;
-			bool irqsafe;
-
-			timer = hlist_entry(head->first, struct timer_list, entry);
-			fn = timer->function;
-			data = timer->data;
-			irqsafe = timer->flags & TIMER_IRQSAFE;
-
-			timer_stats_account_timer(timer);
-
-			base->running_timer = timer;
-			detach_expired_timer(timer, base);
-
-			if (irqsafe) {
-				spin_unlock(&base->lock);
-				call_timer_fn(timer, fn, data);
-				spin_lock(&base->lock);
-			} else {
-				spin_unlock_irq(&base->lock);
-				call_timer_fn(timer, fn, data);
-				spin_lock_irq(&base->lock);
-			}
+		if (timer->flags & TIMER_IRQSAFE) {
+			spin_unlock(&base->lock);
+			call_timer_fn(timer, fn, data);
+			spin_lock(&base->lock);
+		} else {
+			spin_unlock_irq(&base->lock);
+			call_timer_fn(timer, fn, data);
+			spin_lock_irq(&base->lock);
 		}
 	}
-	base->running_timer = NULL;
-	spin_unlock_irq(&base->lock);
+}
+
+static int __collect_expired_timers(struct timer_base *base,
+				    struct hlist_head *heads)
+{
+	unsigned long clk = base->clk;
+	struct hlist_head *vec;
+	int i, levels = 0;
+	unsigned int idx;
+
+	for (i = 0; i < LVL_DEPTH; i++) {
+		idx = (clk & LVL_MASK) + i * LVL_SIZE;
+
+		if (__test_and_clear_bit(idx, base->pending_map)) {
+			vec = base->vectors + idx;
+			hlist_move_list(vec, heads++);
+			levels++;
+		}
+		/* Is it time to look at the next level? */
+		if (clk & LVL_CLK_MASK)
+			break;
+		/* Shift clock for the next level granularity */
+		clk >>= LVL_CLK_SHIFT;
+	}
+	return levels;
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
 /*
- * Find out when the next timer event is due to happen. This
- * is used on S/390 to stop all activity when a CPU is idle.
- * This function needs to be called with interrupts disabled.
+ * Find the next pending bucket of a level. Search from level start (@offset)
+ * + @clk upwards and if nothing there, search from start of the level
+ * (@offset) up to @offset + clk.
  */
-static unsigned long __next_timer_interrupt(struct tvec_base *base)
+static int next_pending_bucket(struct timer_base *base, unsigned offset,
+			       unsigned clk)
 {
-	unsigned long timer_jiffies = base->timer_jiffies;
-	unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA;
-	int index, slot, array, found = 0;
-	struct timer_list *nte;
-	struct tvec *varray[4];
+	unsigned pos, start = offset + clk;
+	unsigned end = offset + LVL_SIZE;
 
-	/* Look for timer events in tv1. */
-	index = slot = timer_jiffies & TVR_MASK;
-	do {
-		hlist_for_each_entry(nte, base->tv1.vec + slot, entry) {
-			if (nte->flags & TIMER_DEFERRABLE)
-				continue;
+	pos = find_next_bit(base->pending_map, end, start);
+	if (pos < end)
+		return pos - start;
 
-			found = 1;
-			expires = nte->expires;
-			/* Look at the cascade bucket(s)? */
-			if (!index || slot < index)
-				goto cascade;
-			return expires;
+	pos = find_next_bit(base->pending_map, start, offset);
+	return pos < start ? pos + LVL_SIZE - start : -1;
+}
+
+/*
+ * Search the first expiring timer in the various clock levels. Caller must
+ * hold base->lock.
+ */
+static unsigned long __next_timer_interrupt(struct timer_base *base)
+{
+	unsigned long clk, next, adj;
+	unsigned lvl, offset = 0;
+
+	next = base->clk + NEXT_TIMER_MAX_DELTA;
+	clk = base->clk;
+	for (lvl = 0; lvl < LVL_DEPTH; lvl++, offset += LVL_SIZE) {
+		int pos = next_pending_bucket(base, offset, clk & LVL_MASK);
+
+		if (pos >= 0) {
+			unsigned long tmp = clk + (unsigned long) pos;
+
+			tmp <<= LVL_SHIFT(lvl);
+			if (time_before(tmp, next))
+				next = tmp;
 		}
-		slot = (slot + 1) & TVR_MASK;
-	} while (slot != index);
-
-cascade:
-	/* Calculate the next cascade event */
-	if (index)
-		timer_jiffies += TVR_SIZE - index;
-	timer_jiffies >>= TVR_BITS;
-
-	/* Check tv2-tv5. */
-	varray[0] = &base->tv2;
-	varray[1] = &base->tv3;
-	varray[2] = &base->tv4;
-	varray[3] = &base->tv5;
-
-	for (array = 0; array < 4; array++) {
-		struct tvec *varp = varray[array];
-
-		index = slot = timer_jiffies & TVN_MASK;
-		do {
-			hlist_for_each_entry(nte, varp->vec + slot, entry) {
-				if (nte->flags & TIMER_DEFERRABLE)
-					continue;
-
-				found = 1;
-				if (time_before(nte->expires, expires))
-					expires = nte->expires;
-			}
-			/*
-			 * Do we still search for the first timer or are
-			 * we looking up the cascade buckets ?
-			 */
-			if (found) {
-				/* Look at the cascade bucket(s)? */
-				if (!index || slot < index)
-					break;
-				return expires;
-			}
-			slot = (slot + 1) & TVN_MASK;
-		} while (slot != index);
-
-		if (index)
-			timer_jiffies += TVN_SIZE - index;
-		timer_jiffies >>= TVN_BITS;
+		/*
+		 * Clock for the next level. If the current level clock lower
+		 * bits are zero, we look at the next level as is. If not we
+		 * need to advance it by one because that's going to be the
+		 * next expiring bucket in that level. base->clk is the next
+		 * expiring jiffie. So in case of:
+		 *
+		 * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
+		 *  0    0    0    0    0    0
+		 *
+		 * we have to look at all levels @index 0. With
+		 *
+		 * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
+		 *  0    0    0    0    0    2
+		 *
+		 * LVL0 has the next expiring bucket @index 2. The upper
+		 * levels have the next expiring bucket @index 1.
+		 *
+		 * In case that the propagation wraps the next level the same
+		 * rules apply:
+		 *
+		 * LVL5 LVL4 LVL3 LVL2 LVL1 LVL0
+		 *  0    0    0    0    F    2
+		 *
+		 * So after looking at LVL0 we get:
+		 *
+		 * LVL5 LVL4 LVL3 LVL2 LVL1
+		 *  0    0    0    1    0
+		 *
+		 * So no propagation from LVL1 to LVL2 because that happened
+		 * with the add already, but then we need to propagate further
+		 * from LVL2 to LVL3.
+		 *
+		 * So the simple check whether the lower bits of the current
+		 * level are 0 or not is sufficient for all cases.
+		 */
+		adj = clk & LVL_CLK_MASK ? 1 : 0;
+		clk >>= LVL_CLK_SHIFT;
+		clk += adj;
 	}
-	return expires;
+	return next;
 }
 
 /*
···
  */
 u64 get_next_timer_interrupt(unsigned long basej, u64 basem)
 {
-	struct tvec_base *base = this_cpu_ptr(&tvec_bases);
+	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 	u64 expires = KTIME_MAX;
 	unsigned long nextevt;
 
···
 		return expires;
 
 	spin_lock(&base->lock);
-	if (base->active_timers) {
-		if (time_before_eq(base->next_timer, base->timer_jiffies))
-			base->next_timer = __next_timer_interrupt(base);
-		nextevt = base->next_timer;
-		if (time_before_eq(nextevt, basej))
-			expires = basem;
-		else
-			expires = basem + (nextevt - basej) * TICK_NSEC;
+	nextevt = __next_timer_interrupt(base);
+	base->next_expiry = nextevt;
+	/*
+	 * We have a fresh next event. Check whether we can forward the base:
+	 */
+	if (time_after(nextevt, jiffies))
+		base->clk = jiffies;
+	else if (time_after(nextevt, base->clk))
+		base->clk = nextevt;
+
+	if (time_before_eq(nextevt, basej)) {
+		expires = basem;
+		base->is_idle = false;
+	} else {
+		expires = basem + (nextevt - basej) * TICK_NSEC;
+		/*
+		 * If we expect to sleep more than a tick, mark the base idle:
+		 */
+		if ((expires - basem) > TICK_NSEC)
+			base->is_idle = true;
 	}
 	spin_unlock(&base->lock);
 
 	return cmp_next_hrtimer_event(basem, expires);
+}
+
+/**
+ * timer_clear_idle - Clear the idle state of the timer base
+ *
+ * Called with interrupts disabled
+ */
+void timer_clear_idle(void)
+{
+	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
+
+	/*
+	 * We do this unlocked. The worst outcome is a remote enqueue sending
+	 * a pointless IPI, but taking the lock would just make the window for
+	 * sending the IPI a few instructions smaller for the cost of taking
+	 * the lock in the exit from idle path.
+	 */
+	base->is_idle = false;
+}
+
+static int collect_expired_timers(struct timer_base *base,
+				  struct hlist_head *heads)
+{
+	/*
+	 * NOHZ optimization. After a long idle sleep we need to forward the
+	 * base to current jiffies. Avoid a loop by searching the bitfield for
+	 * the next expiring timer.
+	 */
+	if ((long)(jiffies - base->clk) > 2) {
+		unsigned long next = __next_timer_interrupt(base);
+
+		/*
+		 * If the next timer is ahead of time forward to current
+		 * jiffies, otherwise forward to the next expiry time:
+		 */
+		if (time_after(next, jiffies)) {
+			/* The call site will increment clock! */
+			base->clk = jiffies - 1;
+			return 0;
+		}
+		base->clk = next;
+	}
+	return __collect_expired_timers(base, heads);
+}
+#else
+static inline int collect_expired_timers(struct timer_base *base,
+					 struct hlist_head *heads)
+{
+	return __collect_expired_timers(base, heads);
 }
 #endif
 
···
 	run_posix_cpu_timers(p);
 }
 
+/**
+ * __run_timers - run all expired timers (if any) on this CPU.
+ * @base: the timer vector to be processed.
+ */
+static inline void __run_timers(struct timer_base *base)
+{
+	struct hlist_head heads[LVL_DEPTH];
+	int levels;
+
+	if (!time_after_eq(jiffies, base->clk))
+		return;
+
+	spin_lock_irq(&base->lock);
+
+	while (time_after_eq(jiffies, base->clk)) {
+
+		levels = collect_expired_timers(base, heads);
+		base->clk++;
+
+		while (levels--)
+			expire_timers(base, heads + levels);
+	}
+	base->running_timer = NULL;
+	spin_unlock_irq(&base->lock);
+}
+
 /*
  * This function runs timers and the timer-tq in bottom half context.
  */
 static void run_timer_softirq(struct softirq_action *h)
 {
-	struct tvec_base *base = this_cpu_ptr(&tvec_bases);
+	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
 
-	if (time_after_eq(jiffies, base->timer_jiffies))
-		__run_timers(base);
+	__run_timers(base);
+	if (IS_ENABLED(CONFIG_NO_HZ_COMMON) && base->nohz_active)
+		__run_timers(this_cpu_ptr(&timer_bases[BASE_DEF]));
 }
 
 /*
···
  */
 void run_local_timers(void)
 {
+	struct timer_base *base = this_cpu_ptr(&timer_bases[BASE_STD]);
+
 	hrtimer_run_queues();
+	/* Raise the softirq only if required. */
+	if (time_before(jiffies, base->clk)) {
+		if (!IS_ENABLED(CONFIG_NO_HZ_COMMON) || !base->nohz_active)
+			return;
+		/* CPU is awake, so check the deferrable base. */
+		base++;
+		if (time_before(jiffies, base->clk))
+			return;
+	}
 	raise_softirq(TIMER_SOFTIRQ);
 }
 
···
 	expire = timeout + jiffies;
 
 	setup_timer_on_stack(&timer, process_timeout, (unsigned long)current);
-	__mod_timer(&timer, expire, false, TIMER_NOT_PINNED);
+	__mod_timer(&timer, expire, false);
 	schedule();
 	del_singleshot_timer_sync(&timer);
 
···
 EXPORT_SYMBOL(schedule_timeout_idle);
 
 #ifdef CONFIG_HOTPLUG_CPU
-static void migrate_timer_list(struct tvec_base *new_base, struct hlist_head *head)
+static void migrate_timer_list(struct timer_base *new_base, struct hlist_head *head)
 {
 	struct timer_list *timer;
 	int cpu = new_base->cpu;
 
 	while (!hlist_empty(head)) {
 		timer = hlist_entry(head->first, struct timer_list, entry);
-		/* We ignore the accounting on the dying cpu */
 		detach_timer(timer, false);
 		timer->flags = (timer->flags & ~TIMER_BASEMASK) | cpu;
 		internal_add_timer(new_base, timer);
···
 
 static void migrate_timers(int cpu)
 {
-	struct tvec_base *old_base;
-	struct tvec_base *new_base;
-	int i;
+	struct timer_base *old_base;
+	struct timer_base *new_base;
+	int b, i;
 
 	BUG_ON(cpu_online(cpu));
-	old_base = per_cpu_ptr(&tvec_bases, cpu);
-	new_base = get_cpu_ptr(&tvec_bases);
-	/*
-	 * The caller is globally serialized and nobody else
-	 * takes two locks at once, deadlock is not possible.
-	 */
-	spin_lock_irq(&new_base->lock);
-	spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
-	BUG_ON(old_base->running_timer);
+	for (b = 0; b < NR_BASES; b++) {
+		old_base = per_cpu_ptr(&timer_bases[b], cpu);
+		new_base = get_cpu_ptr(&timer_bases[b]);
+		/*
+		 * The caller is globally serialized and nobody else
+		 * takes two locks at once, deadlock is not possible.
+		 */
+		spin_lock_irq(&new_base->lock);
+		spin_lock_nested(&old_base->lock, SINGLE_DEPTH_NESTING);
 
-	for (i = 0; i < TVR_SIZE; i++)
-		migrate_timer_list(new_base, old_base->tv1.vec + i);
-	for (i = 0; i < TVN_SIZE; i++) {
-		migrate_timer_list(new_base, old_base->tv2.vec + i);
-		migrate_timer_list(new_base, old_base->tv3.vec + i);
-		migrate_timer_list(new_base, old_base->tv4.vec + i);
-		migrate_timer_list(new_base, old_base->tv5.vec + i);
+		BUG_ON(old_base->running_timer);
+
+		for (i = 0; i < WHEEL_SIZE; i++)
+			migrate_timer_list(new_base, old_base->vectors + i);
+
+		spin_unlock(&old_base->lock);
+		spin_unlock_irq(&new_base->lock);
+		put_cpu_ptr(&timer_bases);
 	}
-
-	old_base->active_timers = 0;
-	old_base->all_timers = 0;
-
-	spin_unlock(&old_base->lock);
-	spin_unlock_irq(&new_base->lock);
-	put_cpu_ptr(&tvec_bases);
 }
 
 static int timer_cpu_notify(struct notifier_block *self,
···
 
 static void __init init_timer_cpu(int cpu)
 {
-	struct tvec_base *base = per_cpu_ptr(&tvec_bases, cpu);
+	struct timer_base *base;
+	int i;
 
-	base->cpu = cpu;
-	spin_lock_init(&base->lock);
-
-	base->timer_jiffies = jiffies;
-	base->next_timer = base->timer_jiffies;
+	for (i = 0; i < NR_BASES; i++) {
+		base = per_cpu_ptr(&timer_bases[i], cpu);
+		base->cpu = cpu;
+		spin_lock_init(&base->lock);
+		base->clk = jiffies;
+	}
 }
 
 static void __init init_timer_cpus(void)
···
 }
 
 /**
- * usleep_range - Drop in replacement for udelay where wakeup is flexible
+ * usleep_range - Sleep for an approximate time
  * @min: Minimum time in usecs to sleep
  * @max: Maximum time in usecs to sleep
+ *
+ * In non-atomic context where the exact wakeup time is flexible, use
+ * usleep_range() instead of udelay().  The sleep improves responsiveness
+ * by avoiding the CPU-hogging busy-wait of udelay(), and the range reduces
+ * power usage by allowing hrtimers to take advantage of an already-
+ * scheduled interrupt instead of scheduling a new one just for this sleep.
  */
 void __sched usleep_range(unsigned long min, unsigned long max)
 {

kernel/time/timer_stats.c

···
 
 static int tstats_show(struct seq_file *m, void *v)
 {
-	struct timespec period;
+	struct timespec64 period;
 	struct entry *entry;
 	unsigned long ms;
 	long events = 0;
···
 
 	time = ktime_sub(time_stop, time_start);
 
-	period = ktime_to_timespec(time);
+	period = ktime_to_timespec64(time);
 	ms = period.tv_nsec / 1000000;
 
 	seq_puts(m, "Timer Stats Version: v0.3\n");
-	seq_printf(m, "Sample period: %ld.%03ld s\n", period.tv_sec, ms);
+	seq_printf(m, "Sample period: %ld.%03ld s\n", (long)period.tv_sec, ms);
 	if (atomic_read(&overflow_count))
 		seq_printf(m, "Overflow: %d entries\n", atomic_read(&overflow_count));
 	seq_printf(m, "Collection: %s\n", timer_stats_active ? "active" : "inactive");

lib/random32.c

···
 
 static void __init __prandom_start_seed_timer(void)
 {
-	set_timer_slack(&seed_timer, HZ);
 	seed_timer.expires = jiffies + msecs_to_jiffies(40 * MSEC_PER_SEC);
 	add_timer(&seed_timer);
 }

net/ipv4/inet_connection_sock.c

···
 		if (req->num_timeout++ == 0)
 			atomic_dec(&queue->young);
 		timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX);
-		mod_timer_pinned(&req->rsk_timer, jiffies + timeo);
+		mod_timer(&req->rsk_timer, jiffies + timeo);
 		return;
 	}
 drop:
···
 	req->num_timeout = 0;
 	req->sk = NULL;
 
-	setup_timer(&req->rsk_timer, reqsk_timer_handler, (unsigned long)req);
-	mod_timer_pinned(&req->rsk_timer, jiffies + timeout);
+	setup_pinned_timer(&req->rsk_timer, reqsk_timer_handler,
+			    (unsigned long)req);
+	mod_timer(&req->rsk_timer, jiffies + timeout);
 
 	inet_ehash_insert(req_to_sk(req), NULL);
 	/* before letting lookups find us, make sure all req fields

net/ipv4/inet_timewait_sock.c

···
 		tw->tw_prot	    = sk->sk_prot_creator;
 		atomic64_set(&tw->tw_cookie, atomic64_read(&sk->sk_cookie));
 		twsk_net_set(tw, sock_net(sk));
-		setup_timer(&tw->tw_timer, tw_timer_handler, (unsigned long)tw);
+		setup_pinned_timer(&tw->tw_timer, tw_timer_handler,
+				   (unsigned long)tw);
 		/*
 		 * Because we use RCU lookups, we should not set tw_refcnt
 		 * to a non null value before everything is setup for this
···
 
 	tw->tw_kill = timeo <= 4*HZ;
 	if (!rearm) {
-		BUG_ON(mod_timer_pinned(&tw->tw_timer, jiffies + timeo));
+		BUG_ON(mod_timer(&tw->tw_timer, jiffies + timeo));
 		atomic_inc(&tw->tw_dr->tw_count);
 	} else {
 		mod_timer_pending(&tw->tw_timer, jiffies + timeo);