x86/asm/tsc: Rename native_read_tsc() to rdtsc()

Now that there is no paravirt TSC, the "native" is
inappropriate. The function does RDTSC, so give it the obvious
name: rdtsc().

Suggested-by: Borislav Petkov <[e-mail]>
Signed-off-by: Andy Lutomirski <[e-mail]>
Signed-off-by: Borislav Petkov <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Brian Gerst <[e-mail]>
Cc: Denys Vlasenko <[e-mail]>
Cc: H. Peter Anvin <[e-mail]>
Cc: Huang Rui <[e-mail]>
Cc: John Stultz <[e-mail]>
Cc: Len Brown <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Ralf Baechle <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: kvm ML <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
[ Ported it to v4.2-rc1. ]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/boot/compressed/aslr.c

···
 
 	if (has_cpuflag(X86_FEATURE_TSC)) {
 		debug_putstr(" RDTSC");
-		raw = native_read_tsc();
+		raw = rdtsc();
 
 		random ^= raw;
 		use_i8254 = false;

arch/x86/entry/vdso/vclock_gettime.c

···
 	 * but no one has ever seen it happen.
 	 */
 	rdtsc_barrier();
-	ret = (cycle_t)native_read_tsc();
+	ret = (cycle_t)rdtsc();
 
 	last = gtod->cycle_last;
 

arch/x86/include/asm/msr.h

···
 extern int rdmsr_safe_regs(u32 regs[8]);
 extern int wrmsr_safe_regs(u32 regs[8]);
 
-static __always_inline unsigned long long native_read_tsc(void)
+/**
+ * rdtsc() - returns the current TSC without ordering constraints
+ *
+ * rdtsc() returns the result of RDTSC as a 64-bit integer.  The
+ * only ordering constraint it supplies is the ordering implied by
+ * "asm volatile": it will put the RDTSC in the place you expect.  The
+ * CPU can and will speculatively execute that RDTSC, though, so the
+ * results can be non-monotonic if compared on different CPUs.
+ */
+static __always_inline unsigned long long rdtsc(void)
 {
 	DECLARE_ARGS(val, low, high);
 

arch/x86/include/asm/pvclock.h

···
 static __always_inline
 u64 pvclock_get_nsec_offset(const struct pvclock_vcpu_time_info *src)
 {
-	u64 delta = native_read_tsc() - src->tsc_timestamp;
+	u64 delta = rdtsc() - src->tsc_timestamp;
 	return pvclock_scale_delta(delta, src->tsc_to_system_mul,
 				   src->tsc_shift);
 }

arch/x86/include/asm/stackprotector.h

···
 	 * on during the bootup the random pool has true entropy too.
 	 */
 	get_random_bytes(&canary, sizeof(canary));
-	tsc = native_read_tsc();
+	tsc = rdtsc();
 	canary += tsc + (tsc << 32UL);
 
 	current->stack_canary = canary;

arch/x86/include/asm/tsc.h

···
 		return 0;
 #endif
 
-	return native_read_tsc();
+	return rdtsc();
 }
 
 extern void tsc_init(void);

arch/x86/kernel/apb_timer.c

···
 
 	/* Verify whether apbt counter works */
 	t1 = dw_apb_clocksource_read(clocksource_apbt);
-	start = native_read_tsc();
+	start = rdtsc();
 
 	/*
 	 * We don't know the TSC frequency yet, but waiting for
···
 	 */
 	do {
 		rep_nop();
-		now = native_read_tsc();
+		now = rdtsc();
 	} while ((now - start) < 200000UL);
 
 	/* APBT is the only always on clocksource, it has to work! */
···
 	old = dw_apb_clocksource_read(clocksource_apbt);
 	old += loop;
 
-	t1 = native_read_tsc();
+	t1 = rdtsc();
 
 	do {
 		new = dw_apb_clocksource_read(clocksource_apbt);
 	} while (new < old);
 
-	t2 = native_read_tsc();
+	t2 = rdtsc();
 
 	shift = 5;
 	if (unlikely(loop >> shift == 0)) {

arch/x86/kernel/apic/apic.c

···
 {
 	u64 tsc;
 
-	tsc = native_read_tsc();
+	tsc = rdtsc();
 	wrmsrl(MSR_IA32_TSC_DEADLINE, tsc + (((u64) delta) * TSC_DIVISOR));
 	return 0;
 }
···
 	unsigned long pm = acpi_pm_read_early();
 
 	if (cpu_has_tsc)
-		tsc = native_read_tsc();
+		tsc = rdtsc();
 
 	switch (lapic_cal_loops++) {
 	case 0:
···
 	long long max_loops = cpu_khz ? cpu_khz : 1000000;
 
 	if (cpu_has_tsc)
-		tsc = native_read_tsc();
+		tsc = rdtsc();
 
 	if (disable_apic) {
 		disable_ioapic_support();
···
 		}
 		if (queued) {
 			if (cpu_has_tsc && cpu_khz) {
-				ntsc = native_read_tsc();
+				ntsc = rdtsc();
 				max_loops = (cpu_khz << 10) - (ntsc - tsc);
 			} else
 				max_loops--;

arch/x86/kernel/cpu/amd.c

···
 
 		n = K6_BUG_LOOP;
 		f_vide = vide;
-		d = native_read_tsc();
+		d = rdtsc();
 		while (n--)
 			f_vide();
-		d2 = native_read_tsc();
+		d2 = rdtsc();
 		d = d2-d;
 
 		if (d > 20*K6_BUG_LOOP)

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

···
 {
 	memset(m, 0, sizeof(struct mce));
 	m->cpu = m->extcpu = smp_processor_id();
-	m->tsc = native_read_tsc();
+	m->tsc = rdtsc();
 	/* We hope get_seconds stays lockless */
 	m->time = get_seconds();
 	m->cpuvendor = boot_cpu_data.x86_vendor;
···
 {
 	unsigned long *cpu_tsc = (unsigned long *)data;
 
-	cpu_tsc[smp_processor_id()] = native_read_tsc();
+	cpu_tsc[smp_processor_id()] = rdtsc();
 }
 
 static int mce_apei_read_done;

arch/x86/kernel/espfix_64.c

···
 	 */
 	if (!arch_get_random_long(&rand)) {
 		/* The constant is an arbitrary large prime */
-		rand = native_read_tsc();
+		rand = rdtsc();
 		rand *= 0xc345c6b72fd16123UL;
 	}
 

arch/x86/kernel/hpet.c

···
 
 	/* Verify whether hpet counter works */
 	t1 = hpet_readl(HPET_COUNTER);
-	start = native_read_tsc();
+	start = rdtsc();
 
 	/*
 	 * We don't know the TSC frequency yet, but waiting for
···
 	 */
 	do {
 		rep_nop();
-		now = native_read_tsc();
+		now = rdtsc();
 	} while ((now - start) < 200000UL);
 
 	if (t1 == hpet_readl(HPET_COUNTER)) {

arch/x86/kernel/trace_clock.c

···
 	u64 ret;
 
 	rdtsc_barrier();
-	ret = native_read_tsc();
+	ret = rdtsc();
 
 	return ret;
 }

arch/x86/kernel/tsc.c

···
 
 	data = cyc2ns_write_begin(cpu);
 
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 	ns_now = cycles_2_ns(tsc_now);
 
 	/*
···
 	}
 
 	/* read the Time Stamp Counter: */
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 
 	/* return the value in ns */
 	return cycles_2_ns(tsc_now);

arch/x86/kvm/lapic.c

···
 
 	tsc_deadline = apic->lapic_timer.expired_tscdeadline;
 	apic->lapic_timer.expired_tscdeadline = 0;
-	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+	guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, rdtsc());
 	trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline);
 
 	/* __delay is delay_tsc whenever the hardware has TSC, thus always.  */
···
 		local_irq_save(flags);
 
 		now = apic->lapic_timer.timer.base->get_time();
-		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, native_read_tsc());
+		guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu, rdtsc());
 		if (likely(tscdeadline > guest_tsc)) {
 			ns = (tscdeadline - guest_tsc) * 1000000ULL;
 			do_div(ns, this_tsc_khz);

arch/x86/kvm/svm.c

···
 {
 	u64 tsc;
 
-	tsc = svm_scale_tsc(vcpu, native_read_tsc());
+	tsc = svm_scale_tsc(vcpu, rdtsc());
 
 	return target_tsc - tsc;
 }
···
 	switch (msr_info->index) {
 	case MSR_IA32_TSC: {
 		msr_info->data = svm->vmcb->control.tsc_offset +
-			svm_scale_tsc(vcpu, native_read_tsc());
+			svm_scale_tsc(vcpu, rdtsc());
 
 		break;
 	}

arch/x86/kvm/vmx.c

···
 {
 	u64 host_tsc, tsc_offset;
 
-	host_tsc = native_read_tsc();
+	host_tsc = rdtsc();
 	tsc_offset = vmcs_read64(TSC_OFFSET);
 	return host_tsc + tsc_offset;
 }
···
 
 static u64 vmx_compute_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
 {
-	return target_tsc - native_read_tsc();
+	return target_tsc - rdtsc();
 }
 
 static bool guest_cpuid_has_vmx(struct kvm_vcpu *vcpu)

arch/x86/kvm/x86.c

···
 	 * but no one has ever seen it happen.
 	 */
 	rdtsc_barrier();
-	ret = (cycle_t)native_read_tsc();
+	ret = (cycle_t)rdtsc();
 
 	last = pvclock_gtod_data.clock.cycle_last;
 
···
 		return 1;
 	}
 	if (!use_master_clock) {
-		host_tsc = native_read_tsc();
+		host_tsc = rdtsc();
 		kernel_ns = get_kernel_ns();
 	}
 
···
 
 	if (unlikely(vcpu->cpu != cpu) || check_tsc_unstable()) {
 		s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
-				native_read_tsc() - vcpu->arch.last_host_tsc;
+				rdtsc() - vcpu->arch.last_host_tsc;
 		if (tsc_delta < 0)
 			mark_tsc_unstable("KVM discovered backwards TSC");
 		if (check_tsc_unstable()) {
···
 {
 	kvm_x86_ops->vcpu_put(vcpu);
 	kvm_put_guest_fpu(vcpu);
-	vcpu->arch.last_host_tsc = native_read_tsc();
+	vcpu->arch.last_host_tsc = rdtsc();
 }
 
 static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
···
 		hw_breakpoint_restore();
 
 	vcpu->arch.last_guest_tsc = kvm_x86_ops->read_l1_tsc(vcpu,
-							   native_read_tsc());
+							   rdtsc());
 
 	vcpu->mode = OUTSIDE_GUEST_MODE;
 	smp_wmb();
···
 	if (ret != 0)
 		return ret;
 
-	local_tsc = native_read_tsc();
+	local_tsc = rdtsc();
 	stable = !check_tsc_unstable();
 	list_for_each_entry(kvm, &vm_list, vm_list) {
 		kvm_for_each_vcpu(i, vcpu, kvm) {

arch/x86/lib/delay.c

···
 	preempt_disable();
 	cpu = smp_processor_id();
 	rdtsc_barrier();
-	bclock = native_read_tsc();
+	bclock = rdtsc();
 	for (;;) {
 		rdtsc_barrier();
-		now = native_read_tsc();
+		now = rdtsc();
 		if ((now - bclock) >= loops)
 			break;
 
···
 			loops -= (now - bclock);
 			cpu = smp_processor_id();
 			rdtsc_barrier();
-			bclock = native_read_tsc();
+			bclock = rdtsc();
 		}
 	}
 	preempt_enable();
···
 int read_current_timer(unsigned long *timer_val)
 {
 	if (delay_fn == delay_tsc) {
-		*timer_val = native_read_tsc();
+		*timer_val = rdtsc();
 		return 0;
 	}
 	return -1;

drivers/cpufreq/intel_pstate.c

···
 	local_irq_save(flags);
 	rdmsrl(MSR_IA32_APERF, aperf);
 	rdmsrl(MSR_IA32_MPERF, mperf);
-	tsc = native_read_tsc();
+	tsc = rdtsc();
 	local_irq_restore(flags);
 
 	cpu->last_sample_time = cpu->sample.time;

drivers/input/gameport/gameport.c

···
 
 	for(i = 0; i < 50; i++) {
 		local_irq_save(flags);
-		t1 = native_read_tsc();
+		t1 = rdtsc();
 		for (t = 0; t < 50; t++) gameport_read(gameport);
-		t2 = native_read_tsc();
+		t2 = rdtsc();
 		local_irq_restore(flags);
 		udelay(i * 10);
 		if (t2 - t1 < tx) tx = t2 - t1;

drivers/input/joystick/analog.c

···
 
 #include <linux/i8253.h>
 
-#define GET_TIME(x)	do { if (cpu_has_tsc) x = (unsigned int)native_read_tsc(); else x = get_time_pit(); } while (0)
+#define GET_TIME(x)	do { if (cpu_has_tsc) x = (unsigned int)rdtsc(); else x = get_time_pit(); } while (0)
 #define DELTA(x,y)	(cpu_has_tsc ? ((y) - (x)) : ((x) - (y) + ((x) < (y) ? PIT_TICK_RATE / HZ : 0)))
 #define TIME_NAME	(cpu_has_tsc?"TSC":"PIT")
 static unsigned int get_time_pit(void)
···
         return count;
 }
 #elif defined(__x86_64__)
-#define GET_TIME(x)	do { x = (unsigned int)native_read_tsc(); } while (0)
+#define GET_TIME(x)	do { x = (unsigned int)rdtsc(); } while (0)
 #define DELTA(x,y)	((y)-(x))
 #define TIME_NAME	"TSC"
 #elif defined(__alpha__) || defined(CONFIG_MN10300) || defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_TILE)

drivers/net/hamradio/baycom_epp.c

···
 #define GETTICK(x)                                                \
 ({                                                                \
 	if (cpu_has_tsc)                                          \
-		x = (unsigned int)native_read_tsc();		  \
+		x = (unsigned int)rdtsc();		  \
 })
 #else /* __i386__ */
 #define GETTICK(x)

drivers/thermal/intel_powerclamp.c

···
 
 	/* check result for the last window */
 	msr_now = pkg_state_counter();
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 
 	/* calculate pkg cstate vs tsc ratio */
 	if (!msr_last || !tsc_last)
···
 	u64 val64;
 
 	msr_now = pkg_state_counter();
-	tsc_now = native_read_tsc();
+	tsc_now = rdtsc();
 	jiffies_now = jiffies;
 
 	/* calculate pkg cstate vs tsc ratio */

tools/power/cpupower/debug/kernel/cpufreq-test_tsc.c

···
 
 	printk(KERN_DEBUG "start--> \n");
 	then = read_pmtmr();
-	then_tsc = native_read_tsc();
+	then_tsc = rdtsc();
 	for (i=0;i<20;i++) {
 		mdelay(100);
 		now = read_pmtmr();
-		now_tsc = native_read_tsc();
+		now_tsc = rdtsc();
 		diff = (now - then) & 0xFFFFFF;
 		diff_tsc = now_tsc - then_tsc;
 		printk(KERN_DEBUG "t1: %08u t2: %08u diff_pmtmr: %08u diff_tsc: %016llu\n", then, now, diff, diff_tsc);