From: James Clark <james.clark@linaro.org> mainline inclusion from mainline-v6.18-rc1 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/9066 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ----------------------------------------------- FEAT_SPEv1p4 (optional from Armv8.8) adds some new filter bits and also makes some previously available bits unavailable again e.g: E[30], bit [30] When FEAT_SPEv1p4 is _not_ implemented ... Continuing to hard code the valid filter bits for each version isn't scalable, and it also doesn't work for filter bits that aren't related to SPE version. For example most bits have a further condition: E[15], bit [15] When ... and filtering on event 15 is supported: Whether "filtering on event 15" is implemented or not is only discoverable from the TRM of that specific CPU or by probing PMSEVFR_EL1. Instead of hard coding them, write all 1s to the PMSEVFR_EL1 register and read it back to discover the RES0 bits. Unsupported bits are RAZ/WI so should read as 0s. For any hardware that doesn't strictly follow RAZ/WI for unsupported filters: Any bits that should have been supported in a specific SPE version but now incorrectly appear to be RES0 wouldn't have worked anyway, so it's better to fail to open events that request them rather than behaving unexpectedly. Bits that aren't implemented but also aren't RAZ/WI will be incorrectly reported as supported, but allowing them to be used is harmless. Testing on N1SDP shows the probed RES0 bits to be the same as the hard coded ones. The FVP with SPEv1p4 shows only additional new RES0 bits, i.e. no previously hard coded RES0 bits are missing. Tested-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Signed-off-by: Yushan Wang <wangyushan12@huawei.com> Signed-off-by: Ying Jiang <jiangying44@h-partners.com> --- arch/arm64/include/asm/sysreg.h | 9 --------- drivers/perf/arm_spe_pmu.c | 23 +++++++---------------- 2 files changed, 7 insertions(+), 25 deletions(-) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 1cbbacb2482a..13354cdaf200 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -321,15 +321,6 @@ #define SYS_PAR_EL1_F BIT(0) #define SYS_PAR_EL1_FST GENMASK(6, 1) -/*** Statistical Profiling Extension ***/ -#define PMSEVFR_EL1_RES0_IMP \ - (GENMASK_ULL(47, 32) | GENMASK_ULL(23, 16) | GENMASK_ULL(11, 8) |\ - BIT_ULL(6) | BIT_ULL(4) | BIT_ULL(2) | BIT_ULL(0)) -#define PMSEVFR_EL1_RES0_V1P1 \ - (PMSEVFR_EL1_RES0_IMP & ~(BIT_ULL(18) | BIT_ULL(17) | BIT_ULL(11))) -#define PMSEVFR_EL1_RES0_V1P2 \ - (PMSEVFR_EL1_RES0_V1P1 & ~BIT_ULL(6)) - /* Buffer error reporting */ #define PMBSR_EL1_FAULT_FSC_SHIFT PMBSR_EL1_MSS_SHIFT #define PMBSR_EL1_FAULT_FSC_MASK PMBSR_EL1_MSS_MASK diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index 19a54371140c..d629c10629db 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -100,6 +100,7 @@ struct arm_spe_pmu { #define SPE_PMU_FEAT_DEV_PROBED (1UL << 63) u64 features; + u64 pmsevfr_res0; u16 max_record_sz; u16 align; struct perf_output_handle __percpu *handle; @@ -733,20 +734,6 @@ static irqreturn_t arm_spe_pmu_irq_handler(int irq, void *dev) return IRQ_HANDLED; } -static u64 arm_spe_pmsevfr_res0(u16 pmsver) -{ - switch (pmsver) { - case ID_AA64DFR0_EL1_PMSVer_IMP: - return PMSEVFR_EL1_RES0_IMP; - case ID_AA64DFR0_EL1_PMSVer_V1P1: - return PMSEVFR_EL1_RES0_V1P1; - case ID_AA64DFR0_EL1_PMSVer_V1P2: - /* Return the highest version we support in default */ - default: - return PMSEVFR_EL1_RES0_V1P2; - } -} - /* Perf callbacks */ static int arm_spe_pmu_event_init(struct perf_event *event) { @@ -762,10 +749,10 @@ static int arm_spe_pmu_event_init(struct perf_event *event) !cpumask_test_cpu(event->cpu, &spe_pmu->supported_cpus)) return -ENOENT; - if (arm_spe_event_to_pmsevfr(event) & arm_spe_pmsevfr_res0(spe_pmu->pmsver)) + if (arm_spe_event_to_pmsevfr(event) & spe_pmu->pmsevfr_res0) return -EOPNOTSUPP; - if (arm_spe_event_to_pmsnevfr(event) & arm_spe_pmsevfr_res0(spe_pmu->pmsver)) + if (arm_spe_event_to_pmsnevfr(event) & spe_pmu->pmsevfr_res0) return -EOPNOTSUPP; if (attr->exclude_idle) @@ -1157,6 +1144,10 @@ static void __arm_spe_pmu_dev_probe(void *info) spe_pmu->counter_sz = 16; } + /* Write all 1s and then read back. Unsupported filter bits are RAZ/WI. */ + write_sysreg_s(U64_MAX, SYS_PMSEVFR_EL1); + spe_pmu->pmsevfr_res0 = ~read_sysreg_s(SYS_PMSEVFR_EL1); + dev_info(dev, "probed SPEv1.%d for CPUs %*pbl [max_record_sz %u, align %u, features 0x%llx]\n", spe_pmu->pmsver - 1, cpumask_pr_args(&spe_pmu->supported_cpus), -- 2.33.0