From: Marc Zyngier maz@kernel.org

mainline inclusion from mainline-v6.9-rc1 commit 6f57c6be2a0889cc0fd32b0cd2eb25dfee20dde3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

--------------------------------

It has become obvious that HCR_EL2.NV serves the exact same use as VCPU_HYP_CONTEXT, only in an architectural way. So just drop the flag for good.

Reviewed-by: Joey Gouly joey.gouly@arm.com Reviewed-by: Oliver Upton oliver.upton@linux.dev Link: https://lore.kernel.org/r/20240419102935.1935571-5-maz@kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Junhao He hejunhao3@huawei.com --- arch/arm64/include/asm/kvm_host.h | 2 -- arch/arm64/kvm/hyp/vhe/switch.c | 7 +------ 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index ac8115098ec9..a4a21911a78a 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -755,8 +755,6 @@ struct kvm_vcpu_arch { #define DEBUG_STATE_SAVE_SPE __vcpu_single_flag(iflags, BIT(5)) /* Save TRBE context if active */ #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) -/* vcpu running in HYP context */ -#define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7))

/* SVE enabled for host EL0 */ #define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 448b17080d36..def038487f2a 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -183,7 +183,7 @@ static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code) * If we were in HYP context on entry, adjust the PSTATE view * so that the usual helpers work correctly. */ - if (unlikely(vcpu_get_flag(vcpu, VCPU_HYP_CONTEXT))) { + if (vcpu_has_nv(vcpu) && (read_sysreg(hcr_el2) & HCR_NV)) { u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT);

switch (mode) { @@ -232,11 +232,6 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu) sysreg_restore_guest_state_vhe(guest_ctxt); __debug_switch_to_guest(vcpu);

- if (is_hyp_ctxt(vcpu)) - vcpu_set_flag(vcpu, VCPU_HYP_CONTEXT); - else - vcpu_clear_flag(vcpu, VCPU_HYP_CONTEXT); - do { /* Jump in the fire! */ exit_code = __guest_enter(vcpu);

From: Miguel Luis miguel.luis@oracle.com

mainline inclusion from mainline-v6.6-rc1 commit 41f6c9344713e6b895a77f2bdd596cf56d4cc197 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

--------------------------------

Some _EL2 encodings are missing. Add them.

Signed-off-by: Miguel Luis miguel.luis@oracle.com Reviewed-by: Eric Auger eric.auger@redhat.com [maz: dropped secure encodings] Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20231023095444.1587322-3-maz@kernel.org Signed-off-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Junhao He hejunhao3@huawei.com --- arch/arm64/include/asm/sysreg.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index cef20e5d105d..5e036fb4a4bf 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -272,6 +272,8 @@ /* ETM */ #define SYS_TRCOSLAR sys_reg(2, 1, 1, 0, 4)

+#define SYS_BRBCR_EL2 sys_reg(2, 4, 9, 0, 0) + #define SYS_MIDR_EL1 sys_reg(3, 0, 0, 0, 0) #define SYS_MPIDR_EL1 sys_reg(3, 0, 0, 0, 5) #define SYS_REVIDR_EL1 sys_reg(3, 0, 0, 0, 6) @@ -488,6 +490,7 @@

#define SYS_SCTLR_EL2 sys_reg(3, 4, 1, 0, 0) #define SYS_ACTLR_EL2 sys_reg(3, 4, 1, 0, 1) +#define SYS_SCTLR2_EL2 sys_reg(3, 4, 1, 0, 3) #define SYS_HCR_EL2 sys_reg(3, 4, 1, 1, 0) #define SYS_MDCR_EL2 sys_reg(3, 4, 1, 1, 1) #define SYS_CPTR_EL2 sys_reg(3, 4, 1, 1, 2) @@ -501,6 +504,7 @@ #define SYS_VTCR_EL2 sys_reg(3, 4, 2, 1, 2)

#define SYS_TRFCR_EL2 sys_reg(3, 4, 1, 2, 1) +#define SYS_VNCR_EL2 sys_reg(3, 4, 2, 2, 0) #define SYS_HAFGRTR_EL2 sys_reg(3, 4, 3, 1, 6) #define SYS_SPSR_EL2 sys_reg(3, 4, 4, 0, 0) #define SYS_ELR_EL2 sys_reg(3, 4, 4, 0, 1) @@ -518,6 +522,18 @@

#define SYS_MAIR_EL2 sys_reg(3, 4, 10, 2, 0) #define SYS_AMAIR_EL2 sys_reg(3, 4, 10, 3, 0) +#define SYS_MPAMHCR_EL2 sys_reg(3, 4, 10, 4, 0) +#define SYS_MPAMVPMV_EL2 sys_reg(3, 4, 10, 4, 1) +#define SYS_MPAM2_EL2 sys_reg(3, 4, 10, 5, 0) +#define __SYS__MPAMVPMx_EL2(x) sys_reg(3, 4, 10, 6, x) +#define SYS_MPAMVPM0_EL2 __SYS__MPAMVPMx_EL2(0) +#define SYS_MPAMVPM1_EL2 __SYS__MPAMVPMx_EL2(1) +#define SYS_MPAMVPM2_EL2 __SYS__MPAMVPMx_EL2(2) +#define SYS_MPAMVPM3_EL2 __SYS__MPAMVPMx_EL2(3) +#define SYS_MPAMVPM4_EL2 __SYS__MPAMVPMx_EL2(4) +#define SYS_MPAMVPM5_EL2 __SYS__MPAMVPMx_EL2(5) +#define SYS_MPAMVPM6_EL2 __SYS__MPAMVPMx_EL2(6) +#define SYS_MPAMVPM7_EL2 __SYS__MPAMVPMx_EL2(7)

#define SYS_MPAMHCR_EL2 sys_reg(3, 4, 10, 4, 0) #define SYS_MPAMVPMV_EL2 sys_reg(3, 4, 10, 4, 1) @@ -573,9 +589,23 @@

#define SYS_CONTEXTIDR_EL2 sys_reg(3, 4, 13, 0, 1) #define SYS_TPIDR_EL2 sys_reg(3, 4, 13, 0, 2) +#define SYS_SCXTNUM_EL2 sys_reg(3, 4, 13, 0, 7) + +#define __AMEV_op2(m) (m & 0x7) +#define __AMEV_CRm(n, m) (n | ((m & 0x8) >> 3)) +#define __SYS__AMEVCNTVOFF0n_EL2(m) sys_reg(3, 4, 13, __AMEV_CRm(0x8, m), __AMEV_op2(m)) +#define SYS_AMEVCNTVOFF0n_EL2(m) __SYS__AMEVCNTVOFF0n_EL2(m) +#define __SYS__AMEVCNTVOFF1n_EL2(m) sys_reg(3, 4, 13, __AMEV_CRm(0xA, m), __AMEV_op2(m)) +#define SYS_AMEVCNTVOFF1n_EL2(m) __SYS__AMEVCNTVOFF1n_EL2(m)

#define SYS_CNTVOFF_EL2 sys_reg(3, 4, 14, 0, 3) #define SYS_CNTHCTL_EL2 sys_reg(3, 4, 14, 1, 0) +#define SYS_CNTHP_TVAL_EL2 sys_reg(3, 4, 14, 2, 0) +#define SYS_CNTHP_CTL_EL2 sys_reg(3, 4, 14, 2, 1) +#define SYS_CNTHP_CVAL_EL2 sys_reg(3, 4, 14, 2, 2) +#define SYS_CNTHV_TVAL_EL2 sys_reg(3, 4, 14, 3, 0) +#define SYS_CNTHV_CTL_EL2 sys_reg(3, 4, 14, 3, 1) +#define SYS_CNTHV_CVAL_EL2 sys_reg(3, 4, 14, 3, 2)

/* VHE encodings for architectural EL0/1 system registers */ #define SYS_BRBCR_EL12 sys_reg(2, 5, 9, 0, 0)

From: Anshuman Khandual anshuman.khandual@arm.com

maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20240613061731.3109448-1-anshuman.k...

--------------------------------

This patch adds definitions related to the Branch Record Buffer Extension (BRBE) as per ARM DDI 0487K.a. These will be used by KVM and a BRBE driver in subsequent patches.

Some existing BRBE definitions in asm/sysreg.h are replaced with equivalent generated definitions.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Marc Zyngier maz@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Mark Rutland mark.rutland@arm.com Reviewed-by: Mark Brown broonie@kernel.org Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Junhao He hejunhao3@huawei.com --- arch/arm64/include/asm/sysreg.h | 14 ++-- arch/arm64/tools/sysreg | 131 ++++++++++++++++++++++++++++++++ 2 files changed, 137 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 5e036fb4a4bf..faba73f948b1 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -197,16 +197,8 @@ #define SYS_DBGVCR32_EL2 sys_reg(2, 4, 0, 7, 0)

#define SYS_BRBINF_EL1(n) sys_reg(2, 1, 8, (n & 15), (((n & 16) >> 2) | 0)) -#define SYS_BRBINFINJ_EL1 sys_reg(2, 1, 9, 1, 0) #define SYS_BRBSRC_EL1(n) sys_reg(2, 1, 8, (n & 15), (((n & 16) >> 2) | 1)) -#define SYS_BRBSRCINJ_EL1 sys_reg(2, 1, 9, 1, 1) #define SYS_BRBTGT_EL1(n) sys_reg(2, 1, 8, (n & 15), (((n & 16) >> 2) | 2)) -#define SYS_BRBTGTINJ_EL1 sys_reg(2, 1, 9, 1, 2) -#define SYS_BRBTS_EL1 sys_reg(2, 1, 9, 0, 2) - -#define SYS_BRBCR_EL1 sys_reg(2, 1, 9, 0, 0) -#define SYS_BRBFCR_EL1 sys_reg(2, 1, 9, 0, 1) -#define SYS_BRBIDR0_EL1 sys_reg(2, 1, 9, 2, 0)

#define SYS_TRCITECR_EL1 sys_reg(3, 0, 1, 2, 3) #define SYS_TRCACATR(m) sys_reg(2, 1, 2, ((m & 7) << 1), (2 | (m >> 3))) @@ -795,6 +787,12 @@ #define OP_DVP_RCTX sys_insn(1, 3, 7, 3, 5) #define OP_CPP_RCTX sys_insn(1, 3, 7, 3, 7)

+/* + * BRBE Instructions + */ +#define BRB_IALL_INSN __emit_inst(0xd5000000 | OP_BRB_IALL | (0x1f)) +#define BRB_INJ_INSN __emit_inst(0xd5000000 | OP_BRB_INJ | (0x1f)) + /* Common SCTLR_ELx flags. */ #define SCTLR_ELx_ENTP2 (BIT(60)) #define SCTLR_ELx_DSSBS (BIT(44)) diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg index 0e7d7f327410..17286210625b 100644 --- a/arch/arm64/tools/sysreg +++ b/arch/arm64/tools/sysreg @@ -1002,6 +1002,137 @@ UnsignedEnum 3:0 BT EndEnum EndSysreg

+ +SysregFields BRBINFx_EL1 +Res0 63:47 +Field 46 CCU +Field 45:32 CC +Res0 31:18 +Field 17 LASTFAILED +Field 16 T +Res0 15:14 +Enum 13:8 TYPE + 0b000000 DIRECT_UNCOND + 0b000001 INDIRECT + 0b000010 DIRECT_LINK + 0b000011 INDIRECT_LINK + 0b000101 RET + 0b000111 ERET + 0b001000 DIRECT_COND + 0b100001 DEBUG_HALT + 0b100010 CALL + 0b100011 TRAP + 0b100100 SERROR + 0b100110 INSN_DEBUG + 0b100111 DATA_DEBUG + 0b101010 ALIGN_FAULT + 0b101011 INSN_FAULT + 0b101100 DATA_FAULT + 0b101110 IRQ + 0b101111 FIQ + 0b110000 IMPDEF_TRAP_EL3 + 0b111001 DEBUG_EXIT +EndEnum +Enum 7:6 EL + 0b00 EL0 + 0b01 EL1 + 0b10 EL2 + 0b11 EL3 +EndEnum +Field 5 MPRED +Res0 4:2 +Enum 1:0 VALID + 0b00 NONE + 0b01 TARGET + 0b10 SOURCE + 0b11 FULL +EndEnum +EndSysregFields + +SysregFields BRBCR_ELx +Res0 63:24 +Field 23 EXCEPTION +Field 22 ERTN +Res0 21:10 +Field 9 FZPSS +Field 8 FZP +Res0 7 +Enum 6:5 TS + 0b01 VIRTUAL + 0b10 GUEST_PHYSICAL + 0b11 PHYSICAL +EndEnum +Field 4 MPRED +Field 3 CC +Res0 2 +Field 1 ExBRE +Field 0 E0BRE +EndSysregFields + +Sysreg BRBCR_EL1 2 1 9 0 0 +Fields BRBCR_ELx +EndSysreg + +Sysreg BRBFCR_EL1 2 1 9 0 1 +Res0 63:30 +Enum 29:28 BANK + 0b00 BANK_0 + 0b01 BANK_1 +EndEnum +Res0 27:23 +Field 22 CONDDIR +Field 21 DIRCALL +Field 20 INDCALL +Field 19 RTN +Field 18 INDIRECT +Field 17 DIRECT +Field 16 EnI +Res0 15:8 +Field 7 PAUSED +Field 6 LASTFAILED +Res0 5:0 +EndSysreg + +Sysreg BRBTS_EL1 2 1 9 0 2 +Field 63:0 TS +EndSysreg + +Sysreg BRBINFINJ_EL1 2 1 9 1 0 +Fields BRBINFx_EL1 +EndSysreg + +Sysreg BRBSRCINJ_EL1 2 1 9 1 1 +Field 63:0 ADDRESS +EndSysreg + +Sysreg BRBTGTINJ_EL1 2 1 9 1 2 +Field 63:0 ADDRESS +EndSysreg + +Sysreg BRBIDR0_EL1 2 1 9 2 0 +Res0 63:16 +Enum 15:12 CC + 0b0101 20_BIT +EndEnum +Enum 11:8 FORMAT + 0b0000 FORMAT_0 +EndEnum +Enum 7:0 NUMREC + 0b00001000 8 + 0b00010000 16 + 0b00100000 32 + 0b01000000 64 +EndEnum +EndSysreg + +Sysreg BRBCR_EL2 2 4 9 0 0 +Fields BRBCR_ELx +EndSysreg + +Sysreg BRBCR_EL12 2 5 9 0 0 +Fields BRBCR_ELx +EndSysreg + Sysreg ID_AA64ZFR0_EL1 3 0 0 4 4 Res0 63:60 UnsignedEnum 59:56 F64MM

From: Anshuman Khandual anshuman.khandual@arm.com

maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20240613061731.3109448-1-anshuman.k...

--------------------------------

In order to support the Branch Record Buffer Extension (BRBE), we need to extend the arm_pmu framework with some basic infrastructure for branch stack sampling which arm_pmu drivers can opt-in to using. Subsequent patches will use this to add support for BRBE in the PMUv3 driver.

With BRBE, the hardware records branches into a hardware FIFO, which will be sampled by software when perf events overflow. A task may be context- switched an arbitrary number of times between overflows, and to avoid losing samples we need to save the current records when a task is context- switched out. To do these we'll need to use the pmu::sched_task() callback, and we'll also need to allocate some per-task storage space via event flag PERF_ATTACH_TASK_DATA.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Junhao He hejunhao3@huawei.com --- drivers/perf/arm_pmu.c | 42 +++++++++++++++++++++++++++++++++--- include/linux/perf/arm_pmu.h | 32 ++++++++++++++++++++++++++- 2 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index f180148ea7cd..57cd2d1a9a18 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -289,6 +289,23 @@ static void armpmu_start(struct perf_event *event, int flags) { struct arm_pmu *armpmu = to_arm_pmu(event->pmu); struct hw_perf_event *hwc = &event->hw; + struct pmu_hw_events *cpuc = this_cpu_ptr(armpmu->hw_events); + int idx; + + /* + * Merge all branch filter requests from different perf + * events being added into this PMU. This includes both + * privilege and branch type filters. + */ + if (armpmu->has_branch_stack) { + cpuc->branch_sample_type = 0; + for (idx = 0; idx < ARMPMU_MAX_HWEVENTS; idx++) { + struct perf_event *event_idx = cpuc->events[idx]; + + if (event_idx && has_branch_stack(event_idx)) + cpuc->branch_sample_type |= event_idx->attr.branch_sample_type; + } + }

/* * ARM pmu always has to reprogram the period, so ignore @@ -317,6 +334,9 @@ armpmu_del(struct perf_event *event, int flags) struct hw_perf_event *hwc = &event->hw; int idx = hwc->idx;

+ if (has_branch_stack(event)) + armpmu->branch_stack_del(event, hw_events); + armpmu_stop(event, PERF_EF_UPDATE); hw_events->events[idx] = NULL; armpmu->clear_event_idx(hw_events, event); @@ -342,6 +362,9 @@ armpmu_add(struct perf_event *event, int flags) if (idx < 0) return idx;

+ if (has_branch_stack(event)) + armpmu->branch_stack_add(event, hw_events); + /* * If there is an event in the counter we are going to use then make * sure it is disabled. @@ -511,13 +534,25 @@ static int armpmu_event_init(struct perf_event *event) !cpumask_test_cpu(event->cpu, &armpmu->supported_cpus)) return -ENOENT;

- /* does not support taken branch sampling */ - if (has_branch_stack(event)) - return -EOPNOTSUPP; + if (has_branch_stack(event)) { + if (!armpmu->has_branch_stack) + return -EOPNOTSUPP; + + if (!armpmu->branch_stack_init(event)) + return -EOPNOTSUPP; + }

return __hw_perf_event_init(event); }

+static void armpmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) +{ + struct arm_pmu *armpmu = to_arm_pmu(pmu_ctx->pmu); + + if (armpmu->sched_task) + armpmu->sched_task(pmu_ctx, sched_in); +} + static void armpmu_enable(struct pmu *pmu) { struct arm_pmu *armpmu = to_arm_pmu(pmu); @@ -881,6 +916,7 @@ struct arm_pmu *armpmu_alloc(void) }

pmu->pmu = (struct pmu) { + .sched_task = armpmu_sched_task, .pmu_enable = armpmu_enable, .pmu_disable = armpmu_disable, .event_init = armpmu_event_init, diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 6fab6e84da43..9afe17653c5a 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -46,6 +46,18 @@ static_assert((PERF_EVENT_FLAG_ARCH & ARMPMU_EVT_63BIT) == ARMPMU_EVT_63BIT); }, \ }

+/* + * Maximum branch record entries which could be processed + * for core perf branch stack sampling support, regardless + * of the hardware support available on a given ARM PMU. + */ +#define MAX_BRANCH_RECORDS 64 + +struct branch_records { + struct perf_branch_stack branch_stack; + struct perf_branch_entry branch_entries[MAX_BRANCH_RECORDS]; +}; + /* The events for a given PMU register set. */ struct pmu_hw_events { /* @@ -72,6 +84,17 @@ struct pmu_hw_events { struct arm_pmu *percpu_pmu;

int irq; + + struct branch_records *branches; + + /* Active context for task events */ + void *branch_context; + + /* Active events requesting branch records */ + unsigned int branch_users; + + /* Active branch sample type filters */ + unsigned long branch_sample_type; };

enum armpmu_attr_groups { @@ -102,8 +125,15 @@ struct arm_pmu { void (*stop)(struct arm_pmu *); void (*reset)(void *); int (*map_event)(struct perf_event *event); + void (*sched_task)(struct perf_event_pmu_context *pmu_ctx, bool sched_in); + bool (*branch_stack_init)(struct perf_event *event); + void (*branch_stack_add)(struct perf_event *event, struct pmu_hw_events *cpuc); + void (*branch_stack_del)(struct perf_event *event, struct pmu_hw_events *cpuc); + void (*branch_stack_reset)(void); int num_events; - bool secure_access; /* 32-bit ARM only */ + unsigned int secure_access : 1, /* 32-bit ARM only */ + has_branch_stack: 1, /* 64-bit ARM only */ + reserved : 30; #define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40 DECLARE_BITMAP(pmceid_bitmap, ARMV8_PMUV3_MAX_COMMON_EVENTS); #define ARMV8_PMUV3_EXT_COMMON_EVENT_BASE 0x4000

From: Anshuman Khandual anshuman.khandual@arm.com

maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20240613061731.3109448-1-anshuman.k...

--------------------------------

This extends recently added branch stack sampling framework in ARMV8 PMU to enable such events via new architecture feature called Branch Record Buffer Extension aka BRBE. This implements all the armv8pmu_branch_xxx() callbacks as expected at ARMV8 PMU level required to drive perf branch stack sampling events. This adds a new config option CONFIG_ARM64_BRBE to encapsulate this BRBE based implementation, available only on ARM64 platforms.

BRBE hardware captures a branch record via three distinct system registers representing branch source address, branch target address, and other branch information. A BRBE buffer implementation is organized as multiple banks of 32 branch records each, which is a collection of BRBSRC_EL1, BRBTGT_EL1 and BRBINF_EL1 registers. Though total BRBE record entries i.e BRBE_MAX_ENTRIES cannot exceed MAX_BRANCH_RECORDS as defined for ARM PMU.

Branch stack sampling is enabled and disabled along with regular PMU events . This adds required function callbacks in armv8pmu_branch_xxx() format, to drive the PMU branch stack hardware when supported. This also adds fallback stub definitions for these callbacks for PMUs which would not have required support.

BRBE hardware attributes get captured in a new reg_brbidr element in struct arm_pmu during armv8pmu_branch_probe() which is called from broader probing function __armv8pmu_probe_pmu(). Attributes such as number of branch record entries implemented in the hardware can be derived from armpmu->reg_brbidr.

BRBE gets enabled via armv8pmu_branch_enable() where it also derives branch filter, and additional requirements from event's 'attr.branch_sample_type' and configures them via BRBFCR_EL1 and BRBCR_EL1 registers.

PMU event overflow triggers IRQ, where current branch records get captured, stitched along with older records available in 'task_ctx', before getting processed for core perf ring buffer. Task context switch outs incrementally save current branch records in event's 'pmu_ctx->task_ctx_data' to optimize workload's branch record samples.

In case multiple events with different branch sample type requests converge on the same PMU, BRBE gets enabled for the merged branch filter accommoding all those event's branch sample type. Captured branch records get filterted in software for an overflown event if BRBE hardware config does not match its branch sample type, while handling the PMU IRQ.

Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Junhao He hejunhao3@huawei.com --- drivers/perf/Kconfig | 11 + drivers/perf/Makefile | 1 + drivers/perf/arm_brbe.c | 1198 +++++++++++++++++++++++++++++++ drivers/perf/arm_pmuv3.c | 160 ++++- drivers/perf/arm_pmuv3_branch.h | 83 +++ include/linux/perf/arm_pmu.h | 5 + 6 files changed, 1457 insertions(+), 1 deletion(-) create mode 100644 drivers/perf/arm_brbe.c create mode 100644 drivers/perf/arm_pmuv3_branch.h

diff --git a/drivers/perf/Kconfig b/drivers/perf/Kconfig index 273d67ecf6d2..4cfafe375b17 100644 --- a/drivers/perf/Kconfig +++ b/drivers/perf/Kconfig @@ -180,6 +180,17 @@ config ARM_SPE_PMU Extension, which provides periodic sampling of operations in the CPU pipeline and reports this via the perf AUX interface.

+config ARM64_BRBE + bool "Enable support for branch stack sampling using FEAT_BRBE" + depends on PERF_EVENTS && ARM64 && ARM_PMU + default y + help + Enable perf support for Branch Record Buffer Extension (BRBE) which + records all branches taken in an execution path. This supports some + branch types and privilege based filtering. It captures additional + relevant information such as cycle count, misprediction and branch + type, branch privilege level etc. + config ARM_DMC620_PMU tristate "Enable PMU support for the ARM DMC-620 memory controller" depends on (ARM64 && ACPI) || COMPILE_TEST diff --git a/drivers/perf/Makefile b/drivers/perf/Makefile index 16b3ec4db916..a8b7bc22e3d6 100644 --- a/drivers/perf/Makefile +++ b/drivers/perf/Makefile @@ -18,6 +18,7 @@ obj-$(CONFIG_RISCV_PMU_SBI) += riscv_pmu_sbi.o obj-$(CONFIG_THUNDERX2_PMU) += thunderx2_pmu.o obj-$(CONFIG_XGENE_PMU) += xgene_pmu.o obj-$(CONFIG_ARM_SPE_PMU) += arm_spe_pmu.o +obj-$(CONFIG_ARM64_BRBE) += arm_brbe.o obj-$(CONFIG_ARM_DMC620_PMU) += arm_dmc620_pmu.o obj-$(CONFIG_MARVELL_CN10K_TAD_PMU) += marvell_cn10k_tad_pmu.o obj-$(CONFIG_MARVELL_CN10K_DDR_PMU) += marvell_cn10k_ddr_pmu.o diff --git a/drivers/perf/arm_brbe.c b/drivers/perf/arm_brbe.c new file mode 100644 index 000000000000..d795e8fd646f --- /dev/null +++ b/drivers/perf/arm_brbe.c @@ -0,0 +1,1198 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Branch Record Buffer Extension Driver. + * + * Copyright (C) 2022-2023 ARM Limited + * + * Author: Anshuman Khandual anshuman.khandual@arm.com + */ +#include "arm_pmuv3_branch.h" + +#define BRBFCR_EL1_BRANCH_FILTERS (BRBFCR_EL1_DIRECT | \ + BRBFCR_EL1_INDIRECT | \ + BRBFCR_EL1_RTN | \ + BRBFCR_EL1_INDCALL | \ + BRBFCR_EL1_DIRCALL | \ + BRBFCR_EL1_CONDDIR) + +#define BRBFCR_EL1_CONFIG_MASK (BRBFCR_EL1_BANK_MASK | \ + BRBFCR_EL1_PAUSED | \ + BRBFCR_EL1_EnI | \ + BRBFCR_EL1_BRANCH_FILTERS) + +/* + * BRBTS_EL1 is currently not used for branch stack implementation + * purpose but BRBCR_ELx.TS needs to have a valid value from all + * available options. BRBCR_ELx_TS_VIRTUAL is selected for this. + */ +#define BRBCR_ELx_DEFAULT_TS FIELD_PREP(BRBCR_ELx_TS_MASK, BRBCR_ELx_TS_VIRTUAL) + +#define BRBCR_ELx_CONFIG_MASK (BRBCR_ELx_EXCEPTION | \ + BRBCR_ELx_ERTN | \ + BRBCR_ELx_CC | \ + BRBCR_ELx_MPRED | \ + BRBCR_ELx_ExBRE | \ + BRBCR_ELx_E0BRE | \ + BRBCR_ELx_FZP | \ + BRBCR_ELx_TS_MASK) + +/* + * BRBE Buffer Organization + * + * BRBE buffer is arranged as multiple banks of 32 branch record + * entries each. An individual branch record in a given bank could + * be accessed, after selecting the bank in BRBFCR_EL1.BANK and + * accessing the registers i.e [BRBSRC, BRBTGT, BRBINF] set with + * indices [0..31]. + * + * Bank 0 + * + * --------------------------------- ------ + * | 00 | BRBSRC | BRBTGT | BRBINF | | 00 | + * --------------------------------- ------ + * | 01 | BRBSRC | BRBTGT | BRBINF | | 01 | + * --------------------------------- ------ + * | .. | BRBSRC | BRBTGT | BRBINF | | .. | + * --------------------------------- ------ + * | 31 | BRBSRC | BRBTGT | BRBINF | | 31 | + * --------------------------------- ------ + * + * Bank 1 + * + * --------------------------------- ------ + * | 32 | BRBSRC | BRBTGT | BRBINF | | 00 | + * --------------------------------- ------ + * | 33 | BRBSRC | BRBTGT | BRBINF | | 01 | + * --------------------------------- ------ + * | .. | BRBSRC | BRBTGT | BRBINF | | .. | + * --------------------------------- ------ + * | 63 | BRBSRC | BRBTGT | BRBINF | | 31 | + * --------------------------------- ------ + */ +#define BRBE_BANK_MAX_ENTRIES 32 +#define BRBE_MAX_BANK 2 +#define BRBE_MAX_ENTRIES (BRBE_BANK_MAX_ENTRIES * BRBE_MAX_BANK) + +#define BRBE_BANK0_IDX_MIN 0 +#define BRBE_BANK0_IDX_MAX 31 +#define BRBE_BANK1_IDX_MIN 32 +#define BRBE_BANK1_IDX_MAX 63 + +struct brbe_regset { + unsigned long brbsrc; + unsigned long brbtgt; + unsigned long brbinf; +}; + +#define PERF_BR_ARM64_MAX (PERF_BR_MAX + PERF_BR_NEW_MAX) + +struct arm64_perf_task_context { + struct brbe_regset store[BRBE_MAX_ENTRIES]; + int nr_brbe_records; + + /* + * Branch Filter Mask + * + * This mask represents all branch record types i.e PERF_BR_XXX + * (as defined in core perf ABI) that can be generated with the + * event's branch_sample_type request. The mask layout could be + * found here. Although the bit 15 i.e PERF_BR_EXTEND_ABI never + * gets set in the mask. + * + * 23 (PERF_BR_MAX + PERF_BR_NEW_MAX) 0 + * | | + * --------------------------------------------------------- + * | Extended ABI section | X | ABI section | + * --------------------------------------------------------- + */ + DECLARE_BITMAP(br_type_mask, PERF_BR_ARM64_MAX); +}; + +static void branch_mask_set_all(unsigned long *event_type_mask) +{ + int idx; + + for (idx = PERF_BR_UNKNOWN; idx < PERF_BR_EXTEND_ABI; idx++) + set_bit(idx, event_type_mask); + + for (idx = PERF_BR_NEW_FAULT_ALGN; idx < PERF_BR_NEW_MAX; idx++) + set_bit(PERF_BR_MAX + idx, event_type_mask); +} + +static void branch_mask_set_arch(unsigned long *event_type_mask) +{ + set_bit(PERF_BR_MAX + PERF_BR_NEW_FAULT_ALGN, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_NEW_FAULT_DATA, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_NEW_FAULT_INST, event_type_mask); + + set_bit(PERF_BR_MAX + PERF_BR_ARM64_FIQ, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_ARM64_DEBUG_HALT, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_ARM64_DEBUG_EXIT, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_ARM64_DEBUG_INST, event_type_mask); + set_bit(PERF_BR_MAX + PERF_BR_ARM64_DEBUG_DATA, event_type_mask); +} + +static void branch_entry_mask(struct perf_branch_entry *entry, + unsigned long *event_type_mask) +{ + u64 idx; + + bitmap_zero(event_type_mask, PERF_BR_ARM64_MAX); + for (idx = PERF_BR_UNKNOWN; idx < PERF_BR_EXTEND_ABI; idx++) { + if (entry->type == idx) + set_bit(idx, event_type_mask); + } + + if (entry->type == PERF_BR_EXTEND_ABI) { + for (idx = PERF_BR_NEW_FAULT_ALGN; idx < PERF_BR_NEW_MAX; idx++) { + if (entry->new_type == idx) + set_bit(PERF_BR_MAX + idx, event_type_mask); + } + } +} + +static void prepare_event_branch_type_mask(struct perf_event *event, + unsigned long *event_type_mask) +{ + u64 branch_sample = event->attr.branch_sample_type; + + bitmap_zero(event_type_mask, PERF_BR_ARM64_MAX); + + /* + * The platform specific branch types might not follow event's + * branch filter requests accurately. Let's add all of them as + * acceptible branch types during the filtering process. + */ + branch_mask_set_arch(event_type_mask); + + if (branch_sample & PERF_SAMPLE_BRANCH_ANY) { + branch_mask_set_all(event_type_mask); + return; + } + + if (branch_sample & PERF_SAMPLE_BRANCH_IND_JUMP) + set_bit(PERF_BR_IND, event_type_mask); + + set_bit(PERF_BR_UNCOND, event_type_mask); + if (branch_sample & PERF_SAMPLE_BRANCH_COND) { + clear_bit(PERF_BR_UNCOND, event_type_mask); + set_bit(PERF_BR_COND, event_type_mask); + } + + if (branch_sample & PERF_SAMPLE_BRANCH_CALL) + set_bit(PERF_BR_CALL, event_type_mask); + + if (branch_sample & PERF_SAMPLE_BRANCH_IND_CALL) + set_bit(PERF_BR_IND_CALL, event_type_mask); + + if (branch_sample & PERF_SAMPLE_BRANCH_ANY_CALL) { + set_bit(PERF_BR_CALL, event_type_mask); + set_bit(PERF_BR_IRQ, event_type_mask); + set_bit(PERF_BR_SYSCALL, event_type_mask); + set_bit(PERF_BR_SERROR, event_type_mask); + + if (branch_sample & PERF_SAMPLE_BRANCH_COND) + set_bit(PERF_BR_COND_CALL, event_type_mask); + } + + if (branch_sample & PERF_SAMPLE_BRANCH_ANY_RETURN) { + set_bit(PERF_BR_RET, event_type_mask); + set_bit(PERF_BR_ERET, event_type_mask); + set_bit(PERF_BR_SYSRET, event_type_mask); + + if (branch_sample & PERF_SAMPLE_BRANCH_COND) + set_bit(PERF_BR_COND_RET, event_type_mask); + } +} + +struct brbe_hw_attr { + int brbe_version; + int brbe_cc; + int brbe_nr; + int brbe_format; +}; + +#define RETURN_READ_BRBSRCN(n) \ + read_sysreg_s(SYS_BRBSRC_EL1(n)) + +#define RETURN_READ_BRBTGTN(n) \ + read_sysreg_s(SYS_BRBTGT_EL1(n)) + +#define RETURN_READ_BRBINFN(n) \ + read_sysreg_s(SYS_BRBINF_EL1(n)) + +#define BRBE_REGN_CASE(n, case_macro) \ + case n: return case_macro(n); break + +#define BRBE_REGN_SWITCH(x, case_macro) \ + do { \ + switch (x) { \ + BRBE_REGN_CASE(0, case_macro); \ + BRBE_REGN_CASE(1, case_macro); \ + BRBE_REGN_CASE(2, case_macro); \ + BRBE_REGN_CASE(3, case_macro); \ + BRBE_REGN_CASE(4, case_macro); \ + BRBE_REGN_CASE(5, case_macro); \ + BRBE_REGN_CASE(6, case_macro); \ + BRBE_REGN_CASE(7, case_macro); \ + BRBE_REGN_CASE(8, case_macro); \ + BRBE_REGN_CASE(9, case_macro); \ + BRBE_REGN_CASE(10, case_macro); \ + BRBE_REGN_CASE(11, case_macro); \ + BRBE_REGN_CASE(12, case_macro); \ + BRBE_REGN_CASE(13, case_macro); \ + BRBE_REGN_CASE(14, case_macro); \ + BRBE_REGN_CASE(15, case_macro); \ + BRBE_REGN_CASE(16, case_macro); \ + BRBE_REGN_CASE(17, case_macro); \ + BRBE_REGN_CASE(18, case_macro); \ + BRBE_REGN_CASE(19, case_macro); \ + BRBE_REGN_CASE(20, case_macro); \ + BRBE_REGN_CASE(21, case_macro); \ + BRBE_REGN_CASE(22, case_macro); \ + BRBE_REGN_CASE(23, case_macro); \ + BRBE_REGN_CASE(24, case_macro); \ + BRBE_REGN_CASE(25, case_macro); \ + BRBE_REGN_CASE(26, case_macro); \ + BRBE_REGN_CASE(27, case_macro); \ + BRBE_REGN_CASE(28, case_macro); \ + BRBE_REGN_CASE(29, case_macro); \ + BRBE_REGN_CASE(30, case_macro); \ + BRBE_REGN_CASE(31, case_macro); \ + default: \ + pr_warn("unknown register index\n"); \ + return -1; \ + } \ + } while (0) + +static inline int buffer_to_brbe_idx(int buffer_idx) +{ + return buffer_idx % BRBE_BANK_MAX_ENTRIES; +} + +static inline u64 get_brbsrc_reg(int buffer_idx) +{ + int brbe_idx = buffer_to_brbe_idx(buffer_idx); + + BRBE_REGN_SWITCH(brbe_idx, RETURN_READ_BRBSRCN); +} + +static inline u64 get_brbtgt_reg(int buffer_idx) +{ + int brbe_idx = buffer_to_brbe_idx(buffer_idx); + + BRBE_REGN_SWITCH(brbe_idx, RETURN_READ_BRBTGTN); +} + +static inline u64 get_brbinf_reg(int buffer_idx) +{ + int brbe_idx = buffer_to_brbe_idx(buffer_idx); + + BRBE_REGN_SWITCH(brbe_idx, RETURN_READ_BRBINFN); +} + +static inline u64 brbe_record_valid(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_VALID_MASK, brbinf); +} + +static inline bool brbe_invalid(u64 brbinf) +{ + return brbe_record_valid(brbinf) == BRBINFx_EL1_VALID_NONE; +} + +static inline bool brbe_record_is_complete(u64 brbinf) +{ + return brbe_record_valid(brbinf) == BRBINFx_EL1_VALID_FULL; +} + +static inline bool brbe_record_is_source_only(u64 brbinf) +{ + return brbe_record_valid(brbinf) == BRBINFx_EL1_VALID_SOURCE; +} + +static inline bool brbe_record_is_target_only(u64 brbinf) +{ + return brbe_record_valid(brbinf) == BRBINFx_EL1_VALID_TARGET; +} + +static inline int brbe_get_in_tx(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_T_MASK, brbinf); +} + +static inline int brbe_get_mispredict(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_MPRED_MASK, brbinf); +} + +static inline int brbe_get_lastfailed(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_LASTFAILED_MASK, brbinf); +} + +static inline int brbe_get_cycles(u64 brbinf) +{ + /* + * Captured cycle count is unknown and hence + * should not be passed on to the user space. + */ + if (brbinf & BRBINFx_EL1_CCU) + return 0; + + return FIELD_GET(BRBINFx_EL1_CC_MASK, brbinf); +} + +static inline int brbe_get_type(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_TYPE_MASK, brbinf); +} + +static inline int brbe_get_el(u64 brbinf) +{ + return FIELD_GET(BRBINFx_EL1_EL_MASK, brbinf); +} + +static inline int brbe_get_numrec(u64 brbidr) +{ + return FIELD_GET(BRBIDR0_EL1_NUMREC_MASK, brbidr); +} + +static inline int brbe_get_format(u64 brbidr) +{ + return FIELD_GET(BRBIDR0_EL1_FORMAT_MASK, brbidr); +} + +static inline int brbe_get_cc_bits(u64 brbidr) +{ + return FIELD_GET(BRBIDR0_EL1_CC_MASK, brbidr); +} + +void armv8pmu_branch_stack_reset(void) +{ + asm volatile(BRB_IALL_INSN); + isb(); +} + +void armv8pmu_branch_stack_add(struct perf_event *event, struct pmu_hw_events *hw_events) +{ + struct arm64_perf_task_context *task_ctx = event->pmu_ctx->task_ctx_data; + + if (event->ctx->task) + prepare_event_branch_type_mask(event, task_ctx->br_type_mask); + + /* + * Reset branch records buffer if a new CPU bound event + * gets scheduled on a PMU. Otherwise existing branch + * records present in the buffer might just leak into + * such events. + * + * Also reset current 'hw_events->branch_context' because + * any previous task bound event now would have lost an + * opportunity for continuous branch records. + */ + if (!event->ctx->task) { + hw_events->branch_context = NULL; + armv8pmu_branch_stack_reset(); + } + + /* + * Reset branch records buffer if a new task event gets + * scheduled on a PMU which might have existing records. + * Otherwise older branch records present in the buffer + * might leak into the new task event. + */ + if (event->ctx->task && hw_events->branch_context != event->ctx) { + hw_events->branch_context = event->ctx; + armv8pmu_branch_stack_reset(); + } + hw_events->branch_users++; +} + +void armv8pmu_branch_stack_del(struct perf_event *event, struct pmu_hw_events *hw_events) +{ + WARN_ON_ONCE(!hw_events->branch_users); + hw_events->branch_users--; + if (!hw_events->branch_users) { + hw_events->branch_context = NULL; + hw_events->branch_sample_type = 0; + } +} + +static bool valid_brbe_nr(int brbe_nr) +{ + return brbe_nr == BRBIDR0_EL1_NUMREC_8 || + brbe_nr == BRBIDR0_EL1_NUMREC_16 || + brbe_nr == BRBIDR0_EL1_NUMREC_32 || + brbe_nr == BRBIDR0_EL1_NUMREC_64; +} + +static bool valid_brbe_cc(int brbe_cc) +{ + return brbe_cc == BRBIDR0_EL1_CC_20_BIT; +} + +static bool valid_brbe_format(int brbe_format) +{ + return brbe_format == BRBIDR0_EL1_FORMAT_FORMAT_0; +} + +static bool valid_brbe_version(int brbe_version) +{ + return brbe_version == ID_AA64DFR0_EL1_BRBE_IMP || + brbe_version == ID_AA64DFR0_EL1_BRBE_BRBE_V1P1; +} + +static void select_brbe_bank(int bank) +{ + u64 brbfcr; + + WARN_ON(bank > 1); + brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); + brbfcr &= ~BRBFCR_EL1_BANK_MASK; + brbfcr |= SYS_FIELD_PREP(BRBFCR_EL1, BANK, bank); + write_sysreg_s(brbfcr, SYS_BRBFCR_EL1); + isb(); +} + +static bool __read_brbe_regset(struct brbe_regset *entry, int idx) +{ + entry->brbinf = get_brbinf_reg(idx); + + if (brbe_invalid(entry->brbinf)) + return false; + + entry->brbsrc = get_brbsrc_reg(idx); + entry->brbtgt = get_brbtgt_reg(idx); + return true; +} + +/* + * Read all BRBE entries in HW until the first invalid entry. + * + * The caller must ensure that the BRBE is not concurrently modifying these + * branch entries. + */ +static int capture_brbe_regset(struct brbe_regset *buf, int nr_hw_entries) +{ + int idx = 0; + + select_brbe_bank(0); + while (idx < nr_hw_entries && idx <= BRBE_BANK0_IDX_MAX) { + if (!__read_brbe_regset(&buf[idx], idx)) + return idx; + idx++; + } + + select_brbe_bank(1); + while (idx < nr_hw_entries && idx <= BRBE_BANK1_IDX_MAX) { + if (!__read_brbe_regset(&buf[idx], idx)) + return idx; + idx++; + } + return idx; +} + +/* + * This function concatenates branch records from stored and live buffer + * up to maximum nr_max records and the stored buffer holds the resultant + * buffer. The concatenated buffer contains all the branch records from + * the live buffer but might contain some from stored buffer considering + * the maximum combined length does not exceed 'nr_max'. + * + * Stored records Live records + * ------------------------------------------------^ + * | S0 | L0 | Newest | + * --------------------------------- | + * | S1 | L1 | | + * --------------------------------- | + * | S2 | L2 | | + * --------------------------------- | + * | S3 | L3 | | + * --------------------------------- | + * | S4 | L4 | nr_max + * --------------------------------- | + * | | L5 | | + * --------------------------------- | + * | | L6 | | + * --------------------------------- | + * | | L7 | | + * --------------------------------- | + * | | | | + * --------------------------------- | + * | | | Oldest | + * ------------------------------------------------V + * + * + * S0 is the newest in the stored records, where as L7 is the oldest in + * the live records. Unless the live buffer is detected as being full + * thus potentially dropping off some older records, L7 and S0 records + * are contiguous in time for a user task context. The stitched buffer + * here represents maximum possible branch records, contiguous in time. + * + * Stored records Live records + * ------------------------------------------------^ + * | L0 | L0 | Newest | + * --------------------------------- | + * | L1 | L1 | | + * --------------------------------- | + * | L2 | L2 | | + * --------------------------------- | + * | L3 | L3 | | + * --------------------------------- | + * | L4 | L4 | nr_max + * --------------------------------- | + * | L5 | L5 | | + * --------------------------------- | + * | L6 | L6 | | + * --------------------------------- | + * | L7 | L7 | | + * --------------------------------- | + * | S0 | | | + * --------------------------------- | + * | S1 | | Oldest | + * ------------------------------------------------V + * | S2 | <----| + * ----------------- | + * | S3 | <----| Dropped off after nr_max + * ----------------- | + * | S4 | <----| + * ----------------- + */ +static int stitch_stored_live_entries(struct brbe_regset *stored, + struct brbe_regset *live, + int nr_stored, int nr_live, + int nr_max) +{ + int nr_move = min(nr_stored, nr_max - nr_live); + + /* Move the tail of the buffer to make room for the new entries */ + memmove(&stored[nr_live], &stored[0], nr_move * sizeof(*stored)); + + /* Copy the new entries into the head of the buffer */ + memcpy(&stored[0], &live[0], nr_live * sizeof(*stored)); + + /* Return the number of entries in the stitched buffer */ + return min(nr_live + nr_stored, nr_max); +} + +static int brbe_branch_save(struct brbe_regset *live, int nr_hw_entries) +{ + u64 brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); + int nr_live; + + write_sysreg_s(brbfcr | BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); + isb(); + + nr_live = capture_brbe_regset(live, nr_hw_entries); + + write_sysreg_s(brbfcr & ~BRBFCR_EL1_PAUSED, SYS_BRBFCR_EL1); + isb(); + + return nr_live; +} + +void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx) +{ + struct arm64_perf_task_context *task_ctx = ctx; + struct brbe_regset live[BRBE_MAX_ENTRIES]; + int nr_live, nr_store, nr_hw_entries; + + nr_hw_entries = brbe_get_numrec(arm_pmu->reg_brbidr); + nr_live = brbe_branch_save(live, nr_hw_entries); + nr_store = task_ctx->nr_brbe_records; + nr_store = stitch_stored_live_entries(task_ctx->store, live, nr_store, + nr_live, nr_hw_entries); + task_ctx->nr_brbe_records = nr_store; +} + +/* + * Generic perf branch filters supported on BRBE + * + * New branch filters need to be evaluated whether they could be supported on + * BRBE. This ensures that such branch filters would not just be accepted, to + * fail silently. PERF_SAMPLE_BRANCH_HV is a special case that is selectively + * supported only on platforms where kernel is in hyp mode. + */ +#define BRBE_EXCLUDE_BRANCH_FILTERS (PERF_SAMPLE_BRANCH_ABORT_TX | \ + PERF_SAMPLE_BRANCH_IN_TX | \ + PERF_SAMPLE_BRANCH_NO_TX | \ + PERF_SAMPLE_BRANCH_CALL_STACK | \ + PERF_SAMPLE_BRANCH_COUNTERS) + +#define BRBE_ALLOWED_BRANCH_FILTERS (PERF_SAMPLE_BRANCH_USER | \ + PERF_SAMPLE_BRANCH_KERNEL | \ + PERF_SAMPLE_BRANCH_HV | \ + PERF_SAMPLE_BRANCH_ANY | \ + PERF_SAMPLE_BRANCH_ANY_CALL | \ + PERF_SAMPLE_BRANCH_ANY_RETURN | \ + PERF_SAMPLE_BRANCH_IND_CALL | \ + PERF_SAMPLE_BRANCH_COND | \ + PERF_SAMPLE_BRANCH_IND_JUMP | \ + PERF_SAMPLE_BRANCH_CALL | \ + PERF_SAMPLE_BRANCH_NO_FLAGS | \ + PERF_SAMPLE_BRANCH_NO_CYCLES | \ + PERF_SAMPLE_BRANCH_TYPE_SAVE | \ + PERF_SAMPLE_BRANCH_HW_INDEX | \ + PERF_SAMPLE_BRANCH_PRIV_SAVE) + +#define BRBE_PERF_BRANCH_FILTERS (BRBE_ALLOWED_BRANCH_FILTERS | \ + BRBE_EXCLUDE_BRANCH_FILTERS) + +bool armv8pmu_branch_attr_valid(struct perf_event *event) +{ + u64 branch_type = event->attr.branch_sample_type; + + /* + * Ensure both perf branch filter allowed and exclude + * masks are always in sync with the generic perf ABI. + */ + BUILD_BUG_ON(BRBE_PERF_BRANCH_FILTERS != (PERF_SAMPLE_BRANCH_MAX - 1)); + + if (branch_type & ~BRBE_ALLOWED_BRANCH_FILTERS) { + pr_debug_once("requested branch filter not supported 0x%llx\n", branch_type); + return false; + } + + /* + * If the event does not have at least one of the privilege + * branch filters as in PERF_SAMPLE_BRANCH_PLM_ALL, the core + * perf will adjust its value based on perf event's existing + * privilege level via attr.exclude_[user|kernel|hv]. + * + * As event->attr.branch_sample_type might have been changed + * when the event reaches here, it is not possible to figure + * out whether the event originally had HV privilege request + * or got added via the core perf. Just report this situation + * once and continue ignoring if there are other instances. + */ + if ((branch_type & PERF_SAMPLE_BRANCH_HV) && !is_kernel_in_hyp_mode()) + pr_debug_once("hypervisor privilege filter not supported 0x%llx\n", branch_type); + + return true; +} + +int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu) +{ + size_t size = sizeof(struct arm64_perf_task_context); + + arm_pmu->pmu.task_ctx_cache = kmem_cache_create("arm64_brbe_task_ctx", size, 0, 0, NULL); + if (!arm_pmu->pmu.task_ctx_cache) + return -ENOMEM; + return 0; +} + +void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu) +{ + kmem_cache_destroy(arm_pmu->pmu.task_ctx_cache); +} + +static int brbe_attributes_probe(struct arm_pmu *armpmu, u32 brbe) +{ + u64 brbidr = read_sysreg_s(SYS_BRBIDR0_EL1); + int brbe_version, brbe_format, brbe_cc, brbe_nr; + + brbe_version = brbe; + brbe_format = brbe_get_format(brbidr); + brbe_cc = brbe_get_cc_bits(brbidr); + brbe_nr = brbe_get_numrec(brbidr); + armpmu->reg_brbidr = brbidr; + + if (!valid_brbe_version(brbe_version) || + !valid_brbe_format(brbe_format) || + !valid_brbe_cc(brbe_cc) || + !valid_brbe_nr(brbe_nr)) + return -EOPNOTSUPP; + return 0; +} + +void armv8pmu_branch_probe(struct arm_pmu *armpmu) +{ + u64 aa64dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1); + u32 brbe; + + /* + * BRBE implementation's branch entries cannot exceed maximum + * branch records supported at the ARM PMU level abstraction. + * Otherwise there is always a possibility of array overflow, + * while processing BRBE branch records. + */ + BUILD_BUG_ON(BRBE_BANK_MAX_ENTRIES > MAX_BRANCH_RECORDS); + + brbe = cpuid_feature_extract_unsigned_field(aa64dfr0, ID_AA64DFR0_EL1_BRBE_SHIFT); + if (!brbe) + return; + + if (brbe_attributes_probe(armpmu, brbe)) + return; + + armpmu->has_branch_stack = 1; +} + +/* + * BRBE supports the following functional branch type filters while + * generating branch records. These branch filters can be enabled, + * either individually or as a group i.e ORing multiple filters + * with each other. + * + * BRBFCR_EL1_CONDDIR - Conditional direct branch + * BRBFCR_EL1_DIRCALL - Direct call + * BRBFCR_EL1_INDCALL - Indirect call + * BRBFCR_EL1_INDIRECT - Indirect branch + * BRBFCR_EL1_DIRECT - Direct branch + * BRBFCR_EL1_RTN - Subroutine return + */ +static u64 branch_type_to_brbfcr(int branch_type) +{ + u64 brbfcr = 0; + + if (branch_type & PERF_SAMPLE_BRANCH_ANY) { + brbfcr |= BRBFCR_EL1_BRANCH_FILTERS; + return brbfcr; + } + + if (branch_type & PERF_SAMPLE_BRANCH_ANY_CALL) { + brbfcr |= BRBFCR_EL1_INDCALL; + brbfcr |= BRBFCR_EL1_DIRCALL; + } + + if (branch_type & PERF_SAMPLE_BRANCH_ANY_RETURN) + brbfcr |= BRBFCR_EL1_RTN; + + if (branch_type & PERF_SAMPLE_BRANCH_IND_CALL) + brbfcr |= BRBFCR_EL1_INDCALL; + + if (branch_type & PERF_SAMPLE_BRANCH_COND) + brbfcr |= BRBFCR_EL1_CONDDIR; + + if (branch_type & PERF_SAMPLE_BRANCH_IND_JUMP) + brbfcr |= BRBFCR_EL1_INDIRECT; + + if (branch_type & PERF_SAMPLE_BRANCH_CALL) + brbfcr |= BRBFCR_EL1_DIRCALL; + + return brbfcr & BRBFCR_EL1_CONFIG_MASK; +} + +/* + * BRBE supports the following privilege mode filters while generating + * branch records. + * + * BRBCR_ELx_E0BRE - EL0 branch records + * BRBCR_ELx_ExBRE - EL1/EL2 branch records + * + * BRBE also supports the following additional functional branch type + * filters while generating branch records. + * + * BRBCR_ELx_EXCEPTION - Exception + * BRBCR_ELx_ERTN - Exception return + */ +static u64 branch_type_to_brbcr(int branch_type) +{ + u64 brbcr = BRBCR_ELx_DEFAULT_TS; + + /* + * BRBE should be paused on PMU interrupt while tracing kernel + * space to stop capturing further branch records. Otherwise + * interrupt handler branch records might get into the samples + * which is not desired. + * + * BRBE need not be paused on PMU interrupt while tracing only + * the user space, because it will automatically be inside the + * prohibited region. But even after PMU overflow occurs, the + * interrupt could still take much more cycles, before it can + * be taken and by that time BRBE will have been overwritten. + * Hence enable pause on PMU interrupt mechanism even for user + * only traces as well. + */ + brbcr |= BRBCR_ELx_FZP; + + if (branch_type & PERF_SAMPLE_BRANCH_USER) + brbcr |= BRBCR_ELx_E0BRE; + + /* + * When running in the hyp mode, writing into BRBCR_EL1 + * actually writes into BRBCR_EL2 instead. Field E2BRE + * is also at the same position as E1BRE. + */ + if (branch_type & PERF_SAMPLE_BRANCH_KERNEL) + brbcr |= BRBCR_ELx_ExBRE; + + if (branch_type & PERF_SAMPLE_BRANCH_HV) { + if (is_kernel_in_hyp_mode()) + brbcr |= BRBCR_ELx_ExBRE; + } + + if (!(branch_type & PERF_SAMPLE_BRANCH_NO_CYCLES)) + brbcr |= BRBCR_ELx_CC; + + if (!(branch_type & PERF_SAMPLE_BRANCH_NO_FLAGS)) + brbcr |= BRBCR_ELx_MPRED; + + /* + * The exception and exception return branches could be + * captured, irrespective of the perf event's privilege. + * If the perf event does not have enough privilege for + * a given exception level, then addresses which falls + * under that exception level will be reported as zero + * for the captured branch record, creating source only + * or target only records. + */ + if (branch_type & PERF_SAMPLE_BRANCH_ANY) { + brbcr |= BRBCR_ELx_EXCEPTION; + brbcr |= BRBCR_ELx_ERTN; + } + + if (branch_type & PERF_SAMPLE_BRANCH_ANY_CALL) + brbcr |= BRBCR_ELx_EXCEPTION; + + if (branch_type & PERF_SAMPLE_BRANCH_ANY_RETURN) + brbcr |= BRBCR_ELx_ERTN; + + return brbcr & BRBCR_ELx_CONFIG_MASK; +} + +void armv8pmu_branch_enable(struct arm_pmu *arm_pmu) +{ + struct pmu_hw_events *cpuc = this_cpu_ptr(arm_pmu->hw_events); + u64 brbfcr, brbcr; + + if (!(cpuc->branch_sample_type && cpuc->branch_users)) + return; + + /* + * BRBE gets configured with a new mismatched branch sample + * type request, overriding any previous branch filters. + */ + brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); + brbfcr &= ~BRBFCR_EL1_CONFIG_MASK; + brbfcr |= branch_type_to_brbfcr(cpuc->branch_sample_type); + write_sysreg_s(brbfcr, SYS_BRBFCR_EL1); + isb(); + + brbcr = read_sysreg_s(SYS_BRBCR_EL1); + brbcr &= ~BRBCR_ELx_CONFIG_MASK; + brbcr |= branch_type_to_brbcr(cpuc->branch_sample_type); + write_sysreg_s(brbcr, SYS_BRBCR_EL1); + isb(); +} + +void armv8pmu_branch_disable(void) +{ + u64 brbfcr, brbcr; + + brbcr = read_sysreg_s(SYS_BRBCR_EL1); + brbfcr = read_sysreg_s(SYS_BRBFCR_EL1); + brbcr &= ~(BRBCR_ELx_E0BRE | BRBCR_ELx_ExBRE); + brbfcr |= BRBFCR_EL1_PAUSED; + write_sysreg_s(brbcr, SYS_BRBCR_EL1); + write_sysreg_s(brbfcr, SYS_BRBFCR_EL1); + isb(); +} + +static void brbe_set_perf_entry_type(struct perf_branch_entry *entry, u64 brbinf) +{ + int brbe_type = brbe_get_type(brbinf); + + switch (brbe_type) { + case BRBINFx_EL1_TYPE_DIRECT_UNCOND: + entry->type = PERF_BR_UNCOND; + break; + case BRBINFx_EL1_TYPE_INDIRECT: + entry->type = PERF_BR_IND; + break; + case BRBINFx_EL1_TYPE_DIRECT_LINK: + entry->type = PERF_BR_CALL; + break; + case BRBINFx_EL1_TYPE_INDIRECT_LINK: + entry->type = PERF_BR_IND_CALL; + break; + case BRBINFx_EL1_TYPE_RET: + entry->type = PERF_BR_RET; + break; + case BRBINFx_EL1_TYPE_DIRECT_COND: + entry->type = PERF_BR_COND; + break; + case BRBINFx_EL1_TYPE_CALL: + entry->type = PERF_BR_CALL; + break; + case BRBINFx_EL1_TYPE_TRAP: + entry->type = PERF_BR_SYSCALL; + break; + case BRBINFx_EL1_TYPE_ERET: + entry->type = PERF_BR_ERET; + break; + case BRBINFx_EL1_TYPE_IRQ: + entry->type = PERF_BR_IRQ; + break; + case BRBINFx_EL1_TYPE_DEBUG_HALT: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_ARM64_DEBUG_HALT; + break; + case BRBINFx_EL1_TYPE_SERROR: + entry->type = PERF_BR_SERROR; + break; + case BRBINFx_EL1_TYPE_INSN_DEBUG: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_ARM64_DEBUG_INST; + break; + case BRBINFx_EL1_TYPE_DATA_DEBUG: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_ARM64_DEBUG_DATA; + break; + case BRBINFx_EL1_TYPE_ALIGN_FAULT: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_NEW_FAULT_ALGN; + break; + case BRBINFx_EL1_TYPE_INSN_FAULT: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_NEW_FAULT_INST; + break; + case BRBINFx_EL1_TYPE_DATA_FAULT: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_NEW_FAULT_DATA; + break; + case BRBINFx_EL1_TYPE_FIQ: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_ARM64_FIQ; + break; + case BRBINFx_EL1_TYPE_DEBUG_EXIT: + entry->type = PERF_BR_EXTEND_ABI; + entry->new_type = PERF_BR_ARM64_DEBUG_EXIT; + break; + default: + pr_warn_once("%d - unknown branch type captured\n", brbe_type); + entry->type = PERF_BR_UNKNOWN; + break; + } +} + +static int brbe_get_perf_priv(u64 brbinf) +{ + int brbe_el = brbe_get_el(brbinf); + + switch (brbe_el) { + case BRBINFx_EL1_EL_EL0: + return PERF_BR_PRIV_USER; + case BRBINFx_EL1_EL_EL1: + return PERF_BR_PRIV_KERNEL; + case BRBINFx_EL1_EL_EL2: + if (is_kernel_in_hyp_mode()) + return PERF_BR_PRIV_KERNEL; + return PERF_BR_PRIV_HV; + default: + pr_warn_once("%d - unknown branch privilege captured\n", brbe_el); + return PERF_BR_PRIV_UNKNOWN; + } +} + +static void capture_brbe_flags(struct perf_branch_entry *entry, struct perf_event *event, + u64 brbinf) +{ + brbe_set_perf_entry_type(entry, brbinf); + + if (!branch_sample_no_cycles(event)) + entry->cycles = brbe_get_cycles(brbinf); + + if (!branch_sample_no_flags(event)) { + /* + * BRBINFx_EL1.LASTFAILED indicates that a TME transaction failed (or + * was cancelled) prior to this record, and some number of records + * prior to this one, may have been generated during an attempt to + * execute the transaction. + */ + entry->abort = brbe_get_lastfailed(brbinf); + + /* + * All these information (i.e transaction state and mispredicts) + * are available for source only and complete branch records. + */ + if (brbe_record_is_complete(brbinf) || + brbe_record_is_source_only(brbinf)) { + entry->mispred = brbe_get_mispredict(brbinf); + entry->predicted = !entry->mispred; + entry->in_tx = brbe_get_in_tx(brbinf); + } + + /* + * Currently TME feature is neither implemented in any hardware + * nor it is being supported in the kernel. Just warn here once + * if TME related information shows up rather unexpectedly. + */ + if (entry->abort || entry->in_tx) + pr_warn_once("Unknown transaction states %d %d\n", + entry->abort, entry->in_tx); + } + + /* + * All these information (i.e branch privilege level) are + * available for target only and complete branch records. + */ + if (brbe_record_is_complete(brbinf) || + brbe_record_is_target_only(brbinf)) + entry->priv = brbe_get_perf_priv(brbinf); +} + +static void brbe_regset_branch_entries(struct pmu_hw_events *cpuc, struct perf_event *event, + struct brbe_regset *regset, int idx) +{ + struct perf_branch_entry *entry = &cpuc->branches->branch_entries[idx]; + u64 brbinf = regset[idx].brbinf; + + perf_clear_branch_entry_bitfields(entry); + if (brbe_record_is_complete(brbinf)) { + entry->from = regset[idx].brbsrc; + entry->to = regset[idx].brbtgt; + } else if (brbe_record_is_source_only(brbinf)) { + entry->from = regset[idx].brbsrc; + entry->to = 0; + } else if (brbe_record_is_target_only(brbinf)) { + entry->from = 0; + entry->to = regset[idx].brbtgt; + } + capture_brbe_flags(entry, event, brbinf); +} + +static void process_branch_entries(struct pmu_hw_events *cpuc, struct perf_event *event, + struct brbe_regset *regset, int nr_regset) +{ + int idx; + + for (idx = 0; idx < nr_regset; idx++) + brbe_regset_branch_entries(cpuc, event, regset, idx); + + cpuc->branches->branch_stack.nr = nr_regset; + cpuc->branches->branch_stack.hw_idx = -1ULL; +} + +void armv8pmu_branch_read(struct pmu_hw_events *cpuc, struct perf_event *event) +{ + struct arm64_perf_task_context *task_ctx = event->pmu_ctx->task_ctx_data; + struct brbe_regset live[BRBE_MAX_ENTRIES]; + int nr_live, nr_store, nr_hw_entries; + + nr_hw_entries = brbe_get_numrec(cpuc->percpu_pmu->reg_brbidr); + nr_live = capture_brbe_regset(live, nr_hw_entries); + if (event->ctx->task) { + nr_store = task_ctx->nr_brbe_records; + nr_store = stitch_stored_live_entries(task_ctx->store, live, nr_store, + nr_live, nr_hw_entries); + process_branch_entries(cpuc, event, task_ctx->store, nr_store); + task_ctx->nr_brbe_records = 0; + } else { + process_branch_entries(cpuc, event, live, nr_live); + } +} + +static bool filter_branch_privilege(struct perf_branch_entry *entry, u64 branch_sample_type) +{ + /* + * Retrieve the privilege level branch filter requests + * from the overall branch sample type. + */ + branch_sample_type &= PERF_SAMPLE_BRANCH_PLM_ALL; + + /* + * The privilege information do not always get captured + * successfully for given BRBE branch record. Hence the + * entry->priv could be analyzed for filtering when the + * information has really been captured. + */ + if (entry->priv) { + if (entry->priv == PERF_BR_PRIV_USER) { + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_USER)) + return false; + } + + if (entry->priv == PERF_BR_PRIV_KERNEL) { + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_KERNEL)) { + if (!is_kernel_in_hyp_mode()) + return false; + + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_HV)) + return false; + } + } + + if (entry->priv == PERF_BR_PRIV_HV) { + /* + * PERF_SAMPLE_BRANCH_HV request actually gets configured + * similar to PERF_SAMPLE_BRANCH_KERNEL when kernel is in + * hyp mode. In that case PERF_BR_PRIV_KERNEL should have + * been reported for corresponding branch records. + */ + pr_warn_once("PERF_BR_PRIV_HV should not have been captured\n"); + } + return true; + } + + if (is_ttbr0_addr(entry->from) || is_ttbr0_addr(entry->to)) { + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_USER)) + return false; + } + + if (is_ttbr1_addr(entry->from) || is_ttbr1_addr(entry->to)) { + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_KERNEL)) { + if (!is_kernel_in_hyp_mode()) + return false; + + if (!(branch_sample_type & PERF_SAMPLE_BRANCH_HV)) + return false; + } + } + return true; +} + +static bool filter_branch_record(struct pmu_hw_events *cpuc, + struct perf_event *event, + struct perf_branch_entry *entry) +{ + struct arm64_perf_task_context *task_ctx = event->pmu_ctx->task_ctx_data; + u64 branch_sample = event->attr.branch_sample_type; + DECLARE_BITMAP(entry_type_mask, PERF_BR_ARM64_MAX); + DECLARE_BITMAP(event_type_mask, PERF_BR_ARM64_MAX); + + if (!filter_branch_privilege(entry, branch_sample)) + return false; + + if (entry->type == PERF_BR_UNKNOWN) + return true; + + if (branch_sample & PERF_SAMPLE_BRANCH_ANY) + return true; + + /* + * Both PMU and event branch filters match here except the privilege + * filters - which have already been tested earlier. Skip functional + * branch type test and just return success. + */ + if ((cpuc->branch_sample_type & ~PERF_SAMPLE_BRANCH_PLM_ALL) == + event->attr.branch_sample_type) + return true; + + branch_entry_mask(entry, entry_type_mask); + if (task_ctx) + return bitmap_subset(entry_type_mask, task_ctx->br_type_mask, PERF_BR_ARM64_MAX); + + prepare_event_branch_type_mask(event, event_type_mask); + return bitmap_subset(entry_type_mask, event_type_mask, PERF_BR_ARM64_MAX); +} + +void arm64_filter_branch_records(struct pmu_hw_events *cpuc, + struct perf_event *event, + struct branch_records *event_records) +{ + struct perf_branch_entry *entry; + int idx, count = 0; + + memset(event_records, 0, sizeof(*event_records)); + for (idx = 0; idx < cpuc->branches->branch_stack.nr; idx++) { + entry = &cpuc->branches->branch_entries[idx]; + if (!filter_branch_record(cpuc, event, entry)) + continue; + + memcpy(&event_records->branch_entries[count], entry, sizeof(*entry)); + count++; + } + event_records->branch_stack.nr = count; +} diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 21ea93740f65..baa700ab5e03 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -26,6 +26,7 @@ #include <linux/nmi.h>

#include <asm/arm_pmuv3.h> +#include "arm_pmuv3_branch.h"

/* ARMv8 Cortex-A53 specific event types. */ #define ARMV8_A53_PERFCTR_PREF_LINEFILL 0xC2 @@ -834,14 +835,70 @@ static void armv8pmu_start(struct arm_pmu *cpu_pmu) armv8pmu_pmcr_write(armv8pmu_pmcr_read() | ARMV8_PMU_PMCR_E);

kvm_vcpu_pmu_resync_el0(); + if (cpu_pmu->has_branch_stack) + armv8pmu_branch_enable(cpu_pmu); }

static void armv8pmu_stop(struct arm_pmu *cpu_pmu) { + if (cpu_pmu->has_branch_stack) + armv8pmu_branch_disable(); + /* Disable all counters */ armv8pmu_pmcr_write(armv8pmu_pmcr_read() & ~ARMV8_PMU_PMCR_E); }

+static void read_branch_records(struct pmu_hw_events *cpuc, + struct perf_event *event, + struct perf_sample_data *data, + bool *branch_captured) +{ + struct branch_records event_records; + + /* + * CPU specific branch records buffer must have been allocated already + * for the hardware records to be captured and processed further. + */ + if (WARN_ON(!cpuc->branches)) + return; + + /* + * When the current task context does not match with the PMU overflown + * event, the captured branch records here cannot be co-related to the + * overflowed event. Report to the user - as if no branch records have + * been captured, and flush branch records. + */ + if (event->ctx->task && (cpuc->branch_context != event->ctx)) + return; + + /* + * Read the branch records from the hardware once after the PMU IRQ + * has been triggered but subsequently same records can be used for + * other events that might have been overflowed simultaneously thus + * saving much CPU cycles. + */ + if (!*branch_captured) { + armv8pmu_branch_read(cpuc, event); + *branch_captured = true; + } + + /* + * Filter captured branch records + * + * PMU captured branch records would contain samples applicable for + * the aggregated branch filters, for all events that got scheduled + * on this PMU simultaneously. Hence these branch records need to + * be filtered first so that each individual event get samples they + * had requested originally. + */ + if (cpuc->branch_sample_type != event->attr.branch_sample_type) { + arm64_filter_branch_records(cpuc, event, &event_records); + perf_sample_save_brstack(data, event, &event_records.branch_stack, NULL); + return; + } + perf_sample_save_brstack(data, event, &cpuc->branches->branch_stack, NULL); +} + static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) { u32 pmovsr; @@ -849,6 +906,7 @@ static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events); struct pt_regs *regs; int idx; + bool branch_captured = false;

/* * Get and reset the IRQ flags @@ -892,6 +950,13 @@ static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) if (!armpmu_event_set_period(event)) continue;

+ /* + * PMU IRQ should remain asserted until all branch records + * are captured and processed into struct perf_sample_data. + */ + if (has_branch_stack(event) && cpu_pmu->has_branch_stack) + read_branch_records(cpuc, event, &data, &branch_captured); + /* * Perf event overflow will queue the processing of the event as * an irq_work which will be taken care of in the handling of @@ -901,6 +966,8 @@ static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu) cpu_pmu->disable(event); } armv8pmu_start(cpu_pmu); + if (cpu_pmu->has_branch_stack) + armv8pmu_branch_stack_reset();

return IRQ_HANDLED; } @@ -991,6 +1058,40 @@ static int armv8pmu_user_event_idx(struct perf_event *event) return event->hw.idx; }

+static bool armv8pmu_branch_stack_init(struct perf_event *event) +{ + if (armv8pmu_branch_attr_valid(event)) { + /* + * If a task gets scheduled out, the current branch records + * get saved in the task's context data, which can be later + * used to fill in the records upon an event overflow. Let's + * enable PERF_ATTACH_TASK_DATA in 'event->attach_state' for + * all branch stack sampling perf events. + */ + event->attach_state |= PERF_ATTACH_TASK_DATA; + return true; + } + return false; +} + +static void armv8pmu_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_in) +{ + struct arm_pmu *armpmu = to_arm_pmu(pmu_ctx->pmu); + void *task_ctx = pmu_ctx->task_ctx_data; + + if (armpmu->has_branch_stack) { + /* Save branch records in task_ctx on sched out */ + if (task_ctx && !sched_in) { + armv8pmu_branch_save(armpmu, task_ctx); + return; + } + + /* Reset branch records on sched in */ + if (sched_in) + armv8pmu_branch_stack_reset(); + } +} + /* * Add an event filter to a given event. */ @@ -1083,6 +1184,9 @@ static void armv8pmu_reset(void *info) pmcr |= ARMV8_PMU_PMCR_LP;

armv8pmu_pmcr_write(pmcr); + + if (cpu_pmu->has_branch_stack) + armv8pmu_branch_stack_reset(); }

static int __armv8_pmuv3_map_event_id(struct arm_pmu *armpmu, @@ -1235,6 +1339,41 @@ static void __armv8pmu_probe_pmu(void *info) cpu_pmu->reg_pmmir = read_pmmir(); else cpu_pmu->reg_pmmir = 0; + + /* + * BRBE is being probed on a single cpu for a + * given PMU. The remaining cpus, are assumed + * to have the exact same BRBE implementation. + */ + armv8pmu_branch_probe(cpu_pmu); +} + +static int branch_records_alloc(struct arm_pmu *armpmu) +{ + struct branch_records __percpu *records; + int cpu; + + records = alloc_percpu_gfp(struct branch_records, GFP_KERNEL); + if (!records) + return -ENOMEM; + + /* + * percpu memory allocated for 'records' gets completely consumed + * here, and never required to be freed up later. So permanently + * losing access to this anchor i.e 'records' is acceptable. + * + * Otherwise this allocation handle would have to be saved up for + * free_percpu() release later if required. + */ + for_each_possible_cpu(cpu) { + struct pmu_hw_events *events_cpu; + struct branch_records *records_cpu; + + events_cpu = per_cpu_ptr(armpmu->hw_events, cpu); + records_cpu = per_cpu_ptr(records, cpu); + events_cpu->branches = records_cpu; + } + return 0; }

static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu) @@ -1251,7 +1390,21 @@ static int armv8pmu_probe_pmu(struct arm_pmu *cpu_pmu) if (ret) return ret;

- return probe.present ? 0 : -ENODEV; + if (!probe.present) + return -ENODEV; + + if (cpu_pmu->has_branch_stack) { + ret = armv8pmu_task_ctx_cache_alloc(cpu_pmu); + if (ret) + return ret; + + ret = branch_records_alloc(cpu_pmu); + if (ret) { + armv8pmu_task_ctx_cache_free(cpu_pmu); + return ret; + } + } + return 0; }

static void armv8pmu_disable_user_access_ipi(void *unused) @@ -1311,6 +1464,11 @@ static int armv8_pmu_init(struct arm_pmu *cpu_pmu, char *name, cpu_pmu->set_event_filter = armv8pmu_set_event_filter;

cpu_pmu->pmu.event_idx = armv8pmu_user_event_idx; + cpu_pmu->sched_task = armv8pmu_sched_task; + cpu_pmu->branch_stack_init = armv8pmu_branch_stack_init; + cpu_pmu->branch_stack_add = armv8pmu_branch_stack_add; + cpu_pmu->branch_stack_del = armv8pmu_branch_stack_del; + cpu_pmu->branch_stack_reset = armv8pmu_branch_stack_reset;

cpu_pmu->name = name; cpu_pmu->map_event = map_event; diff --git a/drivers/perf/arm_pmuv3_branch.h b/drivers/perf/arm_pmuv3_branch.h new file mode 100644 index 000000000000..4142da38cfb5 --- /dev/null +++ b/drivers/perf/arm_pmuv3_branch.h @@ -0,0 +1,83 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Branch Record Buffer Extension Helpers. + * + * Copyright (C) 2022-2023 ARM Limited + * + * Author: Anshuman Khandual anshuman.khandual@arm.com + */ +#include <linux/perf/arm_pmu.h> + +#ifdef CONFIG_ARM64_BRBE +void armv8pmu_branch_stack_add(struct perf_event *event, struct pmu_hw_events *cpuc); +void armv8pmu_branch_stack_del(struct perf_event *event, struct pmu_hw_events *cpuc); +void armv8pmu_branch_stack_reset(void); +void armv8pmu_branch_probe(struct arm_pmu *arm_pmu); +bool armv8pmu_branch_attr_valid(struct perf_event *event); +void armv8pmu_branch_enable(struct arm_pmu *arm_pmu); +void armv8pmu_branch_disable(void); +void armv8pmu_branch_read(struct pmu_hw_events *cpuc, + struct perf_event *event); +void arm64_filter_branch_records(struct pmu_hw_events *cpuc, + struct perf_event *event, + struct branch_records *event_records); +void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx); +int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu); +void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu); +#else +static inline void armv8pmu_branch_stack_add(struct perf_event *event, struct pmu_hw_events *cpuc) +{ +} + +static inline void armv8pmu_branch_stack_del(struct perf_event *event, struct pmu_hw_events *cpuc) +{ +} + +static inline void armv8pmu_branch_stack_reset(void) +{ +} + +static inline void armv8pmu_branch_probe(struct arm_pmu *arm_pmu) +{ +} + +static inline bool armv8pmu_branch_attr_valid(struct perf_event *event) +{ + WARN_ON_ONCE(!has_branch_stack(event)); + return false; +} + +static inline void armv8pmu_branch_enable(struct arm_pmu *arm_pmu) +{ +} + +static inline void armv8pmu_branch_disable(void) +{ +} + +static inline void armv8pmu_branch_read(struct pmu_hw_events *cpuc, + struct perf_event *event) +{ + WARN_ON_ONCE(!has_branch_stack(event)); +} + +static inline void arm64_filter_branch_records(struct pmu_hw_events *cpuc, + struct perf_event *event, + struct branch_records *event_records) +{ + +} + +static inline void armv8pmu_branch_save(struct arm_pmu *arm_pmu, void *ctx) +{ +} + +static inline int armv8pmu_task_ctx_cache_alloc(struct arm_pmu *arm_pmu) +{ + return 0; +} + +static inline void armv8pmu_task_ctx_cache_free(struct arm_pmu *arm_pmu) +{ +} +#endif diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h index 9afe17653c5a..47e07e3db6a4 100644 --- a/include/linux/perf/arm_pmu.h +++ b/include/linux/perf/arm_pmu.h @@ -147,6 +147,11 @@ struct arm_pmu { /* store the PMMIR_EL1 to expose slots */ u64 reg_pmmir;

+#ifdef CONFIG_ARM64_BRBE + /* store the BRBIDR0_EL1 capturing attributes */ + u64 reg_brbidr; +#endif + /* Only to be used by ACPI probing code */ unsigned long acpi_cpuid; };

From: James Clark james.clark@arm.com

maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20240613061731.3109448-1-anshuman.k...

--------------------------------

The test runs quite slowly in the model, so replace "xargs -n1" with "tr ' ' '\n'" which does the same thing but in single digit minutes instead of double digit minutes.

Also reduce the number of loops in the test application. Unfortunately this causes intermittent failures on x86, presumably because the sampling interval is too big to pickup any loops, so keep it the same there.

Cc: Mark Rutland mark.rutland@arm.com Cc: Arnaldo Carvalho de Melo acme@kernel.org Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: James Clark james.clark@arm.com Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Junhao He hejunhao3@huawei.com --- tools/perf/tests/shell/test_brstack.sh | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh index 09908d71c994..283c9a902bbf 100755 --- a/tools/perf/tests/shell/test_brstack.sh +++ b/tools/perf/tests/shell/test_brstack.sh @@ -12,7 +12,6 @@ if ! perf record -o- --no-buildid --branch-filter any,save_type,u -- true > /dev fi

TMPDIR=$(mktemp -d /tmp/__perf_test.program.XXXXX) -TESTPROG="perf test -w brstack"

cleanup() { rm -rf $TMPDIR @@ -20,11 +19,21 @@ cleanup() {

trap cleanup EXIT TERM INT

+is_arm64() { + uname -m | grep -q aarch64 +} + +if is_arm64; then + TESTPROG="perf test -w brstack 5000" +else + TESTPROG="perf test -w brstack" +fi + test_user_branches() { echo "Testing user branch stack sampling"

perf record -o $TMPDIR/perf.data --branch-filter any,save_type,u -- ${TESTPROG} > /dev/null 2>&1 - perf script -i $TMPDIR/perf.data --fields brstacksym | xargs -n1 > $TMPDIR/perf.script + perf script -i $TMPDIR/perf.data --fields brstacksym | tr ' ' '\n' > $TMPDIR/perf.script

# example of branch entries: # brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL @@ -53,7 +62,7 @@ test_filter() { echo "Testing branch stack filtering permutation ($test_filter_filter,$test_filter_expect)"

perf record -o $TMPDIR/perf.data --branch-filter $test_filter_filter,save_type,u -- ${TESTPROG} > /dev/null 2>&1 - perf script -i $TMPDIR/perf.data --fields brstack | xargs -n1 > $TMPDIR/perf.script + perf script -i $TMPDIR/perf.data --fields brstack | tr ' ' '\n' > $TMPDIR/perf.script

# fail if we find any branch type that doesn't match any of the expected ones # also consider UNKNOWN branch types (-)

From: James Clark james.clark@arm.com

maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8EC9K CVE: NA

Reference: https://lore.kernel.org/linux-arm-kernel/20240613061731.3109448-1-anshuman.k...

--------------------------------

Add Arm64 BRBE-specific testing to the existing branch stack sampling test. The test currently passes on the Arm FVP RevC model, but no hardware has been tested yet.

Cc: Mark Rutland mark.rutland@arm.com Cc: Arnaldo Carvalho de Melo acme@kernel.org Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org Co-developed-by: German Gomez german.gomez@arm.com Signed-off-by: German Gomez german.gomez@arm.com Signed-off-by: James Clark james.clark@arm.com Signed-off-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Junhao He hejunhao3@huawei.com --- tools/perf/tests/builtin-test.c | 1 + tools/perf/tests/shell/test_brstack.sh | 42 ++++++++++++++++++++++++-- tools/perf/tests/tests.h | 1 + tools/perf/tests/workloads/Build | 2 ++ tools/perf/tests/workloads/traploop.c | 39 ++++++++++++++++++++++++ 5 files changed, 82 insertions(+), 3 deletions(-) create mode 100644 tools/perf/tests/workloads/traploop.c

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c index cb6f1dd00dc4..7d9e0a311ef9 100644 --- a/tools/perf/tests/builtin-test.c +++ b/tools/perf/tests/builtin-test.c @@ -139,6 +139,7 @@ static struct test_workload *workloads[] = { &workload__sqrtloop, &workload__brstack, &workload__datasym, + &workload__traploop };

static int num_subtests(const struct test_suite *t) diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh index b1fe29bb71b3..b0c96bfae304 100755 --- a/tools/perf/tests/shell/test_brstack.sh +++ b/tools/perf/tests/shell/test_brstack.sh @@ -47,12 +47,43 @@ test_user_branches() { grep -E -m1 "^brstack_foo+[^ ]*/brstack_bench+[^ ]*/RET/.*$" $TMPDIR/perf.script grep -E -m1 "^brstack_bench+[^ ]*/brstack_bench+[^ ]*/COND/.*$" $TMPDIR/perf.script grep -E -m1 "^brstack+[^ ]*/brstack+[^ ]*/UNCOND/.*$" $TMPDIR/perf.script + + if is_arm64; then + # in arm64 with BRBE, we get IRQ entries that correspond + # to any point in the process + grep -m1 "/IRQ/" $TMPDIR/perf.script + fi set +x

# some branch types are still not being tested: # IND COND_CALL COND_RET SYSCALL SYSRET IRQ SERROR NO_TX }

+test_arm64_trap_eret_branches() { + echo "Testing trap & eret branches (arm64 brbe)" + perf record -o $TMPDIR/perf.data --branch-filter any,save_type,u -- \ + perf test -w traploop 250 + perf script -i $TMPDIR/perf.data --fields brstacksym | tr ' ' '\n' > $TMPDIR/perf.script + set -x + # BRBINF<n>.TYPE == TRAP are mapped to PERF_BR_SYSCALL by the BRBE driver + grep -E -m1 "^trap_bench+[^ ]*/[unknown][^ ]*/SYSCALL/" $TMPDIR/perf.script + grep -E -m1 "^[unknown][^ ]*/trap_bench+[^ ]*/ERET/" $TMPDIR/perf.script + set +x +} + +test_arm64_kernel_branches() { + echo "Testing kernel branches (arm64 brbe)" + # skip if perf doesn't have enough privileges + if ! perf record --branch-filter any,k -o- -- true > /dev/null; then + echo "[skipped: not enough privileges]" + return 0 + fi + perf record -o $TMPDIR/perf.data --branch-filter any,k -- uname -a + perf script -i $TMPDIR/perf.data --fields brstack | tr ' ' '\n' > $TMPDIR/perf.script + grep -E -m1 "0xffff[0-9a-f]{12}" $TMPDIR/perf.script + ! egrep -E -m1 "0x0000[0-9a-f]{12}" $TMPDIR/perf.script +} + # first argument <arg0> is the argument passed to "--branch-stack <arg0>,save_type,u" # second argument are the expected branch types for the given filter test_filter() { @@ -75,11 +106,16 @@ set -e

test_user_branches

-test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ" +if is_arm64; then + test_arm64_trap_eret_branches + test_arm64_kernel_branches +fi + +test_filter "any_call" "CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|FAULT_DATA|FAULT_INST" test_filter "call" "CALL|SYSCALL" test_filter "cond" "COND" test_filter "any_ret" "RET|COND_RET|SYSRET|ERET"

test_filter "call,cond" "CALL|SYSCALL|COND" -test_filter "any_call,cond" "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND" -test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET" +test_filter "any_call,cond" "CALL|IND_CALL|COND_CALL|IRQ|SYSCALL|COND|FAULT_DATA|FAULT_INST" +test_filter "cond,any_call,any_ret" "COND|CALL|IND_CALL|COND_CALL|SYSCALL|IRQ|RET|COND_RET|SYSRET|ERET|FAULT_DATA|FAULT_INST" diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h index b394f3ac2d66..c65455da4eaf 100644 --- a/tools/perf/tests/tests.h +++ b/tools/perf/tests/tests.h @@ -205,6 +205,7 @@ DECLARE_WORKLOAD(leafloop); DECLARE_WORKLOAD(sqrtloop); DECLARE_WORKLOAD(brstack); DECLARE_WORKLOAD(datasym); +DECLARE_WORKLOAD(traploop);

extern const char *dso_to_test;

diff --git a/tools/perf/tests/workloads/Build b/tools/perf/tests/workloads/Build index a1f34d5861e3..a9dc93d8468b 100644 --- a/tools/perf/tests/workloads/Build +++ b/tools/perf/tests/workloads/Build @@ -6,8 +6,10 @@ perf-y += leafloop.o perf-y += sqrtloop.o perf-y += brstack.o perf-y += datasym.o +perf-y += traploop.o

CFLAGS_sqrtloop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE CFLAGS_leafloop.o = -g -O0 -fno-inline -fno-omit-frame-pointer -U_FORTIFY_SOURCE CFLAGS_brstack.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE CFLAGS_datasym.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE +CFLAGS_traploop.o = -g -O0 -fno-inline -U_FORTIFY_SOURCE diff --git a/tools/perf/tests/workloads/traploop.c b/tools/perf/tests/workloads/traploop.c new file mode 100644 index 000000000000..7dac94897e49 --- /dev/null +++ b/tools/perf/tests/workloads/traploop.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdlib.h> +#include "../tests.h" + +#define BENCH_RUNS 999999 + +static volatile int cnt; + +#ifdef __aarch64__ +static void trap_bench(void) +{ + unsigned long val; + + asm("mrs %0, ID_AA64ISAR0_EL1" : "=r" (val)); /* TRAP + ERET */ +} +#else +static void trap_bench(void) +{ + +} +#endif + +static int traploop(int argc, const char **argv) +{ + int num_loops = BENCH_RUNS; + + if (argc > 0) + num_loops = atoi(argv[0]); + + while (1) { + if ((cnt++) > num_loops) + break; + + trap_bench(); + } + return 0; +} + +DEFINE_WORKLOAD(traploop);