arm64: perf: Abstract system register accesses away

As we want to enable 32bit support, we need to distanciate the
PMUv3 driver from the AArch64 system register names.

This patch moves all system register accesses to an architecture
specific include file, allowing the 32bit counterpart to be
slotted in at a later time.

Signed-off-by: Marc Zyngier <[e-mail]>
Co-developed-by: Zaid Al-Bassam <[e-mail]>
Signed-off-by: Zaid Al-Bassam <[e-mail]>
Tested-by: Florian Fainelli <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Will Deacon <[e-mail]>

arch/arm64/include/asm/arm_pmuv3.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#ifndef __ASM_PMUV3_H
+#define __ASM_PMUV3_H
+
+#include <asm/cpufeature.h>
+#include <asm/sysreg.h>
+
+#define RETURN_READ_PMEVCNTRN(n) \
+	return read_sysreg(pmevcntr##n##_el0)
+static unsigned long read_pmevcntrn(int n)
+{
+	PMEVN_SWITCH(n, RETURN_READ_PMEVCNTRN);
+	return 0;
+}
+
+#define WRITE_PMEVCNTRN(n) \
+	write_sysreg(val, pmevcntr##n##_el0)
+static void write_pmevcntrn(int n, unsigned long val)
+{
+	PMEVN_SWITCH(n, WRITE_PMEVCNTRN);
+}
+
+#define WRITE_PMEVTYPERN(n) \
+	write_sysreg(val, pmevtyper##n##_el0)
+static void write_pmevtypern(int n, unsigned long val)
+{
+	PMEVN_SWITCH(n, WRITE_PMEVTYPERN);
+}
+
+static inline unsigned long read_pmmir(void)
+{
+	return read_cpuid(PMMIR_EL1);
+}
+
+static inline u32 read_pmuver(void)
+{
+	u64 dfr0 = read_sysreg(id_aa64dfr0_el1);
+
+	return cpuid_feature_extract_unsigned_field(dfr0,
+			ID_AA64DFR0_EL1_PMUVer_SHIFT);
+}
+
+static inline void write_pmcr(u32 val)
+{
+	write_sysreg(val, pmcr_el0);
+}
+
+static inline u32 read_pmcr(void)
+{
+	return read_sysreg(pmcr_el0);
+}
+
+static inline void write_pmselr(u32 val)
+{
+	write_sysreg(val, pmselr_el0);
+}
+
+static inline void write_pmccntr(u64 val)
+{
+	write_sysreg(val, pmccntr_el0);
+}
+
+static inline u64 read_pmccntr(void)
+{
+	return read_sysreg(pmccntr_el0);
+}
+
+static inline void write_pmxevcntr(u32 val)
+{
+	write_sysreg(val, pmxevcntr_el0);
+}
+
+static inline u32 read_pmxevcntr(void)
+{
+	return read_sysreg(pmxevcntr_el0);
+}
+
+static inline void write_pmxevtyper(u32 val)
+{
+	write_sysreg(val, pmxevtyper_el0);
+}
+
+static inline void write_pmcntenset(u32 val)
+{
+	write_sysreg(val, pmcntenset_el0);
+}
+
+static inline void write_pmcntenclr(u32 val)
+{
+	write_sysreg(val, pmcntenclr_el0);
+}
+
+static inline void write_pmintenset(u32 val)
+{
+	write_sysreg(val, pmintenset_el1);
+}
+
+static inline void write_pmintenclr(u32 val)
+{
+	write_sysreg(val, pmintenclr_el1);
+}
+
+static inline void write_pmccfiltr(u32 val)
+{
+	write_sysreg(val, pmccfiltr_el0);
+}
+
+static inline void write_pmovsclr(u32 val)
+{
+	write_sysreg(val, pmovsclr_el0);
+}
+
+static inline u32 read_pmovsclr(void)
+{
+	return read_sysreg(pmovsclr_el0);
+}
+
+static inline void write_pmuserenr(u32 val)
+{
+	write_sysreg(val, pmuserenr_el0);
+}
+
+static inline u32 read_pmceid0(void)
+{
+	return read_sysreg(pmceid0_el0);
+}
+
+static inline u32 read_pmceid1(void)
+{
+	return read_sysreg(pmceid1_el0);
+}
+
+#endif

drivers/perf/arm_pmuv3.c

···
 
 #include <asm/irq_regs.h>
 #include <asm/perf_event.h>
-#include <asm/sysreg.h>
 #include <asm/virt.h>
 
 #include <clocksource/arm_arch_timer.h>
···
 #include <linux/platform_device.h>
 #include <linux/sched_clock.h>
 #include <linux/smp.h>
+
+#include <asm/arm_pmuv3.h>
 
 /* ARMv8 Cortex-A53 specific event types. */
 #define ARMV8_A53_PERFCTR_PREF_LINEFILL				0xC2
···
 #define	ARMV8_IDX_TO_COUNTER(x)	\
 	(((x) - ARMV8_IDX_COUNTER0) & ARMV8_PMU_COUNTER_MASK)
 
-/*
- * This code is really good
- */
-
-#define PMEVN_CASE(n, case_macro) \
-	case n: case_macro(n); break
-
-#define PMEVN_SWITCH(x, case_macro)				\
-	do {							\
-		switch (x) {					\
-		PMEVN_CASE(0,  case_macro);			\
-		PMEVN_CASE(1,  case_macro);			\
-		PMEVN_CASE(2,  case_macro);			\
-		PMEVN_CASE(3,  case_macro);			\
-		PMEVN_CASE(4,  case_macro);			\
-		PMEVN_CASE(5,  case_macro);			\
-		PMEVN_CASE(6,  case_macro);			\
-		PMEVN_CASE(7,  case_macro);			\
-		PMEVN_CASE(8,  case_macro);			\
-		PMEVN_CASE(9,  case_macro);			\
-		PMEVN_CASE(10, case_macro);			\
-		PMEVN_CASE(11, case_macro);			\
-		PMEVN_CASE(12, case_macro);			\
-		PMEVN_CASE(13, case_macro);			\
-		PMEVN_CASE(14, case_macro);			\
-		PMEVN_CASE(15, case_macro);			\
-		PMEVN_CASE(16, case_macro);			\
-		PMEVN_CASE(17, case_macro);			\
-		PMEVN_CASE(18, case_macro);			\
-		PMEVN_CASE(19, case_macro);			\
-		PMEVN_CASE(20, case_macro);			\
-		PMEVN_CASE(21, case_macro);			\
-		PMEVN_CASE(22, case_macro);			\
-		PMEVN_CASE(23, case_macro);			\
-		PMEVN_CASE(24, case_macro);			\
-		PMEVN_CASE(25, case_macro);			\
-		PMEVN_CASE(26, case_macro);			\
-		PMEVN_CASE(27, case_macro);			\
-		PMEVN_CASE(28, case_macro);			\
-		PMEVN_CASE(29, case_macro);			\
-		PMEVN_CASE(30, case_macro);			\
-		default: WARN(1, "Invalid PMEV* index\n");	\
-		}						\
-	} while (0)
-
-#define RETURN_READ_PMEVCNTRN(n) \
-	return read_sysreg(pmevcntr##n##_el0)
-static unsigned long read_pmevcntrn(int n)
-{
-	PMEVN_SWITCH(n, RETURN_READ_PMEVCNTRN);
-	return 0;
-}
-
-#define WRITE_PMEVCNTRN(n) \
-	write_sysreg(val, pmevcntr##n##_el0)
-static void write_pmevcntrn(int n, unsigned long val)
-{
-	PMEVN_SWITCH(n, WRITE_PMEVCNTRN);
-}
-
-#define WRITE_PMEVTYPERN(n) \
-	write_sysreg(val, pmevtyper##n##_el0)
-static void write_pmevtypern(int n, unsigned long val)
-{
-	PMEVN_SWITCH(n, WRITE_PMEVTYPERN);
-}
-
 static inline u32 armv8pmu_pmcr_read(void)
 {
-	return read_sysreg(pmcr_el0);
+	return read_pmcr();
 }
 
 static inline void armv8pmu_pmcr_write(u32 val)
 {
 	val &= ARMV8_PMU_PMCR_MASK;
 	isb();
-	write_sysreg(val, pmcr_el0);
+	write_pmcr(val);
 }
 
 static inline int armv8pmu_has_overflowed(u32 pmovsr)
···
 	u64 value;
 
 	if (idx == ARMV8_IDX_CYCLE_COUNTER)
-		value = read_sysreg(pmccntr_el0);
+		value = read_pmccntr();
 	else
 		value = armv8pmu_read_hw_counter(event);
 
···
 	value = armv8pmu_bias_long_counter(event, value);
 
 	if (idx == ARMV8_IDX_CYCLE_COUNTER)
-		write_sysreg(value, pmccntr_el0);
+		write_pmccntr(value);
 	else
 		armv8pmu_write_hw_counter(event, value);
 }
···
 		armv8pmu_write_evtype(idx, chain_evt);
 	} else {
 		if (idx == ARMV8_IDX_CYCLE_COUNTER)
-			write_sysreg(hwc->config_base, pmccfiltr_el0);
+			write_pmccfiltr(hwc->config_base);
 		else
 			armv8pmu_write_evtype(idx, hwc->config_base);
 	}
···
 	 * enable the counter.
 	 * */
 	isb();
-	write_sysreg(mask, pmcntenset_el0);
+	write_pmcntenset(mask);
 }
 
 static inline void armv8pmu_enable_event_counter(struct perf_event *event)
···
 
 static inline void armv8pmu_disable_counter(u32 mask)
 {
-	write_sysreg(mask, pmcntenclr_el0);
+	write_pmcntenclr(mask);
 	/*
 	 * Make sure the effects of disabling the counter are visible before we
 	 * start configuring the event.
···
 
 static inline void armv8pmu_enable_intens(u32 mask)
 {
-	write_sysreg(mask, pmintenset_el1);
+	write_pmintenset(mask);
 }
 
 static inline void armv8pmu_enable_event_irq(struct perf_event *event)
···
 
 static inline void armv8pmu_disable_intens(u32 mask)
 {
-	write_sysreg(mask, pmintenclr_el1);
+	write_pmintenclr(mask);
 	isb();
 	/* Clear the overflow flag in case an interrupt is pending. */
-	write_sysreg(mask, pmovsclr_el0);
+	write_pmovsclr(mask);
 	isb();
 }
 
···
 	u32 value;
 
 	/* Read */
-	value = read_sysreg(pmovsclr_el0);
+	value = read_pmovsclr();
 
 	/* Write to clear flags */
 	value &= ARMV8_PMU_OVSR_MASK;
-	write_sysreg(value, pmovsclr_el0);
+	write_pmovsclr(value);
 
 	return value;
 }
 
 static void armv8pmu_disable_user_access(void)
 {
-	write_sysreg(0, pmuserenr_el0);
+	write_pmuserenr(0);
 }
 
 static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
···
 	/* Clear any unused counters to avoid leaking their contents */
 	for_each_clear_bit(i, cpuc->used_mask, cpu_pmu->num_events) {
 		if (i == ARMV8_IDX_CYCLE_COUNTER)
-			write_sysreg(0, pmccntr_el0);
+			write_pmccntr(0);
 		else
 			armv8pmu_write_evcntr(i, 0);
 	}
 
-	write_sysreg(0, pmuserenr_el0);
-	write_sysreg(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR, pmuserenr_el0);
+	write_pmuserenr(0);
+	write_pmuserenr(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR);
 }
 
 static void armv8pmu_enable_event(struct perf_event *event)
···
 {
 	struct armv8pmu_probe_info *probe = info;
 	struct arm_pmu *cpu_pmu = probe->pmu;
-	u64 dfr0;
 	u64 pmceid_raw[2];
 	u32 pmceid[2];
 	int pmuver;
 
-	dfr0 = read_sysreg(id_aa64dfr0_el1);
-	pmuver = cpuid_feature_extract_unsigned_field(dfr0,
-			ID_AA64DFR0_EL1_PMUVer_SHIFT);
+	pmuver = read_pmuver();
 	if (pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF ||
 	    pmuver == ID_AA64DFR0_EL1_PMUVer_NI)
 		return;
···
 	/* Add the CPU cycles counter */
 	cpu_pmu->num_events += 1;
 
-	pmceid[0] = pmceid_raw[0] = read_sysreg(pmceid0_el0);
-	pmceid[1] = pmceid_raw[1] = read_sysreg(pmceid1_el0);
+	pmceid[0] = pmceid_raw[0] = read_pmceid0();
+	pmceid[1] = pmceid_raw[1] = read_pmceid1();
 
 	bitmap_from_arr32(cpu_pmu->pmceid_bitmap,
 			     pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
···
 	bitmap_from_arr32(cpu_pmu->pmceid_ext_bitmap,
 			     pmceid, ARMV8_PMUV3_MAX_COMMON_EVENTS);
 
-	/* store PMMIR_EL1 register for sysfs */
+	/* store PMMIR register for sysfs */
 	if (pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P4 && (pmceid_raw[1] & BIT(31)))
-		cpu_pmu->reg_pmmir = read_cpuid(PMMIR_EL1);
+		cpu_pmu->reg_pmmir = read_pmmir();
 	else
 		cpu_pmu->reg_pmmir = 0;
 }

include/linux/perf/arm_pmuv3.h

···
 #define ARMV8_PMU_BUS_WIDTH_SHIFT 16
 #define ARMV8_PMU_BUS_WIDTH_MASK 0xf
 
+/*
+ * This code is really good
+ */
+
+#define PMEVN_CASE(n, case_macro) \
+	case n: case_macro(n); break
+
+#define PMEVN_SWITCH(x, case_macro)				\
+	do {							\
+		switch (x) {					\
+		PMEVN_CASE(0,  case_macro);			\
+		PMEVN_CASE(1,  case_macro);			\
+		PMEVN_CASE(2,  case_macro);			\
+		PMEVN_CASE(3,  case_macro);			\
+		PMEVN_CASE(4,  case_macro);			\
+		PMEVN_CASE(5,  case_macro);			\
+		PMEVN_CASE(6,  case_macro);			\
+		PMEVN_CASE(7,  case_macro);			\
+		PMEVN_CASE(8,  case_macro);			\
+		PMEVN_CASE(9,  case_macro);			\
+		PMEVN_CASE(10, case_macro);			\
+		PMEVN_CASE(11, case_macro);			\
+		PMEVN_CASE(12, case_macro);			\
+		PMEVN_CASE(13, case_macro);			\
+		PMEVN_CASE(14, case_macro);			\
+		PMEVN_CASE(15, case_macro);			\
+		PMEVN_CASE(16, case_macro);			\
+		PMEVN_CASE(17, case_macro);			\
+		PMEVN_CASE(18, case_macro);			\
+		PMEVN_CASE(19, case_macro);			\
+		PMEVN_CASE(20, case_macro);			\
+		PMEVN_CASE(21, case_macro);			\
+		PMEVN_CASE(22, case_macro);			\
+		PMEVN_CASE(23, case_macro);			\
+		PMEVN_CASE(24, case_macro);			\
+		PMEVN_CASE(25, case_macro);			\
+		PMEVN_CASE(26, case_macro);			\
+		PMEVN_CASE(27, case_macro);			\
+		PMEVN_CASE(28, case_macro);			\
+		PMEVN_CASE(29, case_macro);			\
+		PMEVN_CASE(30, case_macro);			\
+		default: WARN(1, "Invalid PMEV* index\n");	\
+		}						\
+	} while (0)
+
 #endif