[PATCH] perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control
From: Rob Herring (Arm)
Date: Wed Oct 02 2024 - 14:44:30 EST
Armv8.9/9.4 PMUv3.9 adds per counter EL0 access controls. Per counter
access is enabled with the UEN bit in PMUSERENR_EL1 register. Individual
counters are enabled/disabled in the PMUACR_EL1 register. When UEN is
set, the CR/ER bits control EL0 write access and must be set to disable
write access.
With the access controls, the clearing of unused counters can be
skipped.
KVM also configures PMUSERENR_EL1 in order to trap to EL2. UEN does not
need to be set for it since only PMUv3.5 is exposed to guests.
Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
---
arch/arm/include/asm/arm_pmuv3.h | 6 ++++++
arch/arm64/include/asm/arm_pmuv3.h | 10 ++++++++++
arch/arm64/tools/sysreg | 8 ++++++++
drivers/perf/arm_pmuv3.c | 29 +++++++++++++++++++----------
include/linux/perf/arm_pmuv3.h | 1 +
5 files changed, 44 insertions(+), 10 deletions(-)
diff --git a/arch/arm/include/asm/arm_pmuv3.h b/arch/arm/include/asm/arm_pmuv3.h
index f63ba8986b24..d242b5e1ca0d 100644
--- a/arch/arm/include/asm/arm_pmuv3.h
+++ b/arch/arm/include/asm/arm_pmuv3.h
@@ -231,6 +231,7 @@ static inline void kvm_vcpu_pmu_resync_el0(void) {}
#define ARMV8_PMU_DFR_VER_V3P1 0x4
#define ARMV8_PMU_DFR_VER_V3P4 0x5
#define ARMV8_PMU_DFR_VER_V3P5 0x6
+#define ARMV8_PMU_DFR_VER_V3P9 0x9
#define ARMV8_PMU_DFR_VER_IMP_DEF 0xF
static inline bool pmuv3_implemented(int pmuver)
@@ -249,6 +250,11 @@ static inline bool is_pmuv3p5(int pmuver)
return pmuver >= ARMV8_PMU_DFR_VER_V3P5;
}
+static inline bool is_pmuv3p9(int pmuver)
+{
+ return pmuver >= ARMV8_PMU_DFR_VER_V3P9;
+}
+
static inline u64 read_pmceid0(void)
{
u64 val = read_sysreg(PMCEID0);
diff --git a/arch/arm64/include/asm/arm_pmuv3.h b/arch/arm64/include/asm/arm_pmuv3.h
index 468a049bc63b..8a777dec8d88 100644
--- a/arch/arm64/include/asm/arm_pmuv3.h
+++ b/arch/arm64/include/asm/arm_pmuv3.h
@@ -152,6 +152,11 @@ static inline void write_pmuserenr(u32 val)
write_sysreg(val, pmuserenr_el0);
}
+static inline void write_pmuacr(u64 val)
+{
+ write_sysreg_s(val, SYS_PMUACR_EL1);
+}
+
static inline u64 read_pmceid0(void)
{
return read_sysreg(pmceid0_el0);
@@ -178,4 +183,9 @@ static inline bool is_pmuv3p5(int pmuver)
return pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P5;
}
+static inline bool is_pmuv3p9(int pmuver)
+{
+ return pmuver >= ID_AA64DFR0_EL1_PMUVer_V3P9;
+}
+
#endif
diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg
index 8d637ac4b7c6..74fb5af91d4f 100644
--- a/arch/arm64/tools/sysreg
+++ b/arch/arm64/tools/sysreg
@@ -1238,6 +1238,7 @@ UnsignedEnum 11:8 PMUVer
0b0110 V3P5
0b0111 V3P7
0b1000 V3P8
+ 0b1001 V3P9
0b1111 IMP_DEF
EndEnum
UnsignedEnum 7:4 TraceVer
@@ -2178,6 +2179,13 @@ Field 4 P
Field 3:0 ALIGN
EndSysreg
+Sysreg PMUACR_EL1 3 0 9 14 4
+Res0 63:33
+Field 32 F0
+Field 31 C
+Field 30:0 P
+EndSysreg
+
Sysreg PMSELR_EL0 3 3 9 12 5
Res0 63:5
Field 4:0 SEL
diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index 0afe02f879b4..bb93d32b86ea 100644
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -770,18 +770,27 @@ static void armv8pmu_enable_user_access(struct arm_pmu *cpu_pmu)
int i;
struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
- /* Clear any unused counters to avoid leaking their contents */
- for_each_andnot_bit(i, cpu_pmu->cntr_mask, cpuc->used_mask,
- ARMPMU_MAX_HWEVENTS) {
- if (i == ARMV8_PMU_CYCLE_IDX)
- write_pmccntr(0);
- else if (i == ARMV8_PMU_INSTR_IDX)
- write_pmicntr(0);
- else
- armv8pmu_write_evcntr(i, 0);
+ if (is_pmuv3p9(cpu_pmu->pmuver)) {
+ u64 mask = 0;
+ for_each_set_bit(i, cpuc->used_mask, ARMPMU_MAX_HWEVENTS) {
+ if (armv8pmu_event_has_user_read(cpuc->events[i]))
+ mask |= BIT(i);
+ }
+ write_pmuacr(mask);
+ } else {
+ /* Clear any unused counters to avoid leaking their contents */
+ for_each_andnot_bit(i, cpu_pmu->cntr_mask, cpuc->used_mask,
+ ARMPMU_MAX_HWEVENTS) {
+ if (i == ARMV8_PMU_CYCLE_IDX)
+ write_pmccntr(0);
+ else if (i == ARMV8_PMU_INSTR_IDX)
+ write_pmicntr(0);
+ else
+ armv8pmu_write_evcntr(i, 0);
+ }
}
- update_pmuserenr(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR);
+ update_pmuserenr(ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_CR | ARMV8_PMU_USERENR_UEN);
}
static void armv8pmu_enable_event(struct perf_event *event)
diff --git a/include/linux/perf/arm_pmuv3.h b/include/linux/perf/arm_pmuv3.h
index 3372c1b56486..d698efba28a2 100644
--- a/include/linux/perf/arm_pmuv3.h
+++ b/include/linux/perf/arm_pmuv3.h
@@ -257,6 +257,7 @@
#define ARMV8_PMU_USERENR_SW (1 << 1) /* PMSWINC can be written at EL0 */
#define ARMV8_PMU_USERENR_CR (1 << 2) /* Cycle counter can be read at EL0 */
#define ARMV8_PMU_USERENR_ER (1 << 3) /* Event counter can be read at EL0 */
+#define ARMV8_PMU_USERENR_UEN (1 << 4) /* Fine grained per counter access at EL0 */
/* Mask for writable bits */
#define ARMV8_PMU_USERENR_MASK (ARMV8_PMU_USERENR_EN | ARMV8_PMU_USERENR_SW | \
ARMV8_PMU_USERENR_CR | ARMV8_PMU_USERENR_ER)
--
2.45.2