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| author | Rob Herring (Arm) <robh@kernel.org> | 2024-10-02 13:43:24 -0500 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-10-28 17:27:15 +0000 |
| commit | 0bbff9ed81654d5f06bfca484681756ee407f924 (patch) | |
| tree | 10ab083995cee3f3802c0ffa2b076dfcfa50d08a /drivers/perf | |
| parent | 759b5fc6cc3e3c5841f6a3e4638b39534b0fc716 (diff) | |
| download | lwn-0bbff9ed81654d5f06bfca484681756ee407f924.tar.gz lwn-0bbff9ed81654d5f06bfca484681756ee407f924.zip | |
perf/arm_pmuv3: Add PMUv3.9 per counter EL0 access control
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@kernel.org>
Link: https://lore.kernel.org/r/20241002184326.1105499-1-robh@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/perf')
| -rw-r--r-- | drivers/perf/arm_pmuv3.c | 29 |
1 files changed, 19 insertions, 10 deletions
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) |