Messages in this thread Patch in this message | | | From | Anshuman Khandual <> | Subject | [RFC V1 11/11] perf: Capture branch privilege information | Date | Mon, 24 Jan 2022 10:00:53 +0530 |
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Platforms like arm64 could capture privilege level information for all the branch records. Hence this adds a new element in the struct branch_entry to record the privilege level information, which could be requested through a new event.attr.branch_sample_type flag PERF_SAMPLE_BRANCH_PRIV_SAVE. While here, update the BRBE driver as required.
Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-perf-users@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> --- drivers/perf/arm_pmu_brbe.c | 28 ++++++++++++++++++++++++ include/linux/perf_event.h | 5 +++++ include/uapi/linux/perf_event.h | 13 ++++++++++- tools/include/uapi/linux/perf_event.h | 13 ++++++++++- tools/perf/Documentation/perf-record.txt | 1 + tools/perf/util/parse-branch-options.c | 1 + 6 files changed, 59 insertions(+), 2 deletions(-)
diff --git a/drivers/perf/arm_pmu_brbe.c b/drivers/perf/arm_pmu_brbe.c index 7cd1208c6c58..d4cbea74c148 100644 --- a/drivers/perf/arm_pmu_brbe.c +++ b/drivers/perf/arm_pmu_brbe.c @@ -270,6 +270,25 @@ static int brbe_fetch_perf_type(u64 brbinf) } } +static int brbe_fetch_perf_priv(u64 brbinf) +{ + int brbe_el = brbe_fetch_el(brbinf); + + switch (brbe_el) { + case BRBINF_EL_EL0: + return PERF_BR_USER; + case BRBINF_EL_EL1: + return PERF_BR_KERNEL; + case BRBINF_EL_EL2: + if (is_kernel_in_hyp_mode()) + return PERF_BR_KERNEL; + return PERF_BR_HV; + default: + pr_warn("unknown branch privilege captured\n"); + return -1; + } +} + static void capture_brbe_flags(struct pmu_hw_events *cpuc, struct perf_event *event, u64 brbinf, int idx) { @@ -302,6 +321,15 @@ static void capture_brbe_flags(struct pmu_hw_events *cpuc, struct perf_event *ev cpuc->brbe_entries[idx].in_tx = brbinf & BRBINF_TX; } } + + if (branch_sample_priv(event)) { + /* + * All these information (i.e branch privilege level) are not + * available for source only branch records. + */ + if (type != BRBINF_VALID_SOURCE) + cpuc->brbe_entries[idx].priv = brbe_fetch_perf_priv(brbinf); + } } /* diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 916ce5102b33..8021b6a30d86 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1688,4 +1688,9 @@ static inline bool branch_sample_hw_index(const struct perf_event *event) { return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_HW_INDEX; } + +static inline bool branch_sample_priv(const struct perf_event *event) +{ + return event->attr.branch_sample_type & PERF_SAMPLE_BRANCH_PRIV_SAVE; +} #endif /* _LINUX_PERF_EVENT_H */ diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 361fdc6b87a0..4d77710f7a4e 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift { PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT = 17, /* save low level index of raw branch records */ + PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privillege mode */ + PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */ }; @@ -233,6 +235,8 @@ enum perf_branch_sample_type { PERF_SAMPLE_BRANCH_HW_INDEX = 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT, + PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT, + PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT, }; @@ -265,6 +269,12 @@ enum { PERF_BR_MAX, }; +enum { + PERF_BR_USER = 0, + PERF_BR_KERNEL = 1, + PERF_BR_HV = 2, +}; + #define PERF_SAMPLE_BRANCH_PLM_ALL \ (PERF_SAMPLE_BRANCH_USER|\ PERF_SAMPLE_BRANCH_KERNEL|\ @@ -1377,7 +1387,8 @@ struct perf_branch_entry { abort:1, /* transaction abort */ cycles:16, /* cycle count to last branch */ type:6, /* branch type */ - reserved:38; + priv:2, /* privilege level */ + reserved:36; }; union perf_sample_weight { diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h index 9a82b8aaed93..a2208400b0b9 100644 --- a/tools/include/uapi/linux/perf_event.h +++ b/tools/include/uapi/linux/perf_event.h @@ -204,6 +204,8 @@ enum perf_branch_sample_type_shift { PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT = 17, /* save low level index of raw branch records */ + PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT = 18, /* save privillege mode */ + PERF_SAMPLE_BRANCH_MAX_SHIFT /* non-ABI */ }; @@ -233,6 +235,8 @@ enum perf_branch_sample_type { PERF_SAMPLE_BRANCH_HW_INDEX = 1U << PERF_SAMPLE_BRANCH_HW_INDEX_SHIFT, + PERF_SAMPLE_BRANCH_PRIV_SAVE = 1U << PERF_SAMPLE_BRANCH_PRIV_SAVE_SHIFT, + PERF_SAMPLE_BRANCH_MAX = 1U << PERF_SAMPLE_BRANCH_MAX_SHIFT, }; @@ -265,6 +269,12 @@ enum { PERF_BR_MAX, }; +enum { + PERF_BR_USER = 0, + PERF_BR_KERNEL = 1, + PERF_BR_HV = 2, +}; + #define PERF_SAMPLE_BRANCH_PLM_ALL \ (PERF_SAMPLE_BRANCH_USER|\ PERF_SAMPLE_BRANCH_KERNEL|\ @@ -1377,7 +1387,8 @@ struct perf_branch_entry { abort:1, /* transaction abort */ cycles:16, /* cycle count to last branch */ type:6, /* branch type */ - reserved:38; + priv:2, /* privilege level */ + reserved:36; }; union perf_sample_weight { diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 9ccc75935bc5..3e33686977a1 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -387,6 +387,7 @@ following filters are defined: - abort_tx: only when the target is a hardware transaction abort - cond: conditional branches - save_type: save branch type during sampling in case binary is not available later + - priv: save privilege state during sampling in case binary is not available later + The option requires at least one branch type among any, any_call, any_ret, ind_call, cond. diff --git a/tools/perf/util/parse-branch-options.c b/tools/perf/util/parse-branch-options.c index bb4aa88c50a8..00588b9db474 100644 --- a/tools/perf/util/parse-branch-options.c +++ b/tools/perf/util/parse-branch-options.c @@ -32,6 +32,7 @@ static const struct branch_mode branch_modes[] = { BRANCH_OPT("call", PERF_SAMPLE_BRANCH_CALL), BRANCH_OPT("save_type", PERF_SAMPLE_BRANCH_TYPE_SAVE), BRANCH_OPT("stack", PERF_SAMPLE_BRANCH_CALL_STACK), + BRANCH_OPT("priv", PERF_SAMPLE_BRANCH_PRIV_SAVE), BRANCH_END }; -- 2.25.1
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