[PATCH V2 2/7] arm64/perf: Update struct arm_pmu for BRBE
From: Anshuman Khandual <hidden>
Date: 2022-09-08 05:11:15
Also in:
linux-perf-users, lkml
Subsystem:
arm pmu profiling and debugging, arm64 port (aarch64 architecture), performance events subsystem, the rest · Maintainers:
Will Deacon, Mark Rutland, Catalin Marinas, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
Although BRBE is an armv8 speciifc HW feature, abstracting out its various function callbacks at the struct arm_pmu level is preferred, as it cleaner , easier to follow and maintain. Besides some helpers i.e brbe_supported(), brbe_probe() and brbe_reset() might not fit seamlessly, when tried to be embedded via existing arm_pmu helpers in the armv8 implementation. Updates the struct arm_pmu to include all required helpers that will drive BRBE functionality for a given PMU implementation. These are the following. - brbe_filter : Convert perf event filters into BRBE HW filters - brbe_probe : Probe BRBE HW and capture its attributes - brbe_enable : Enable BRBE HW with a given config - brbe_disable : Disable BRBE HW - brbe_read : Read BRBE buffer for captured branch records - brbe_reset : Reset BRBE buffer - brbe_supported: Whether BRBE is supported or not A BRBE driver implementation needs to provide these functionalities. 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: Catalin Marinas <catalin.marinas@arm.com> 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 <redacted> --- arch/arm64/kernel/perf_event.c | 36 ++++++++++++++++++++++++++++++++++ include/linux/perf/arm_pmu.h | 21 ++++++++++++++++++++ 2 files changed, 57 insertions(+)
diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index cb69ff1e6138..e7013699171f 100644
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c@@ -1025,6 +1025,35 @@ static int armv8pmu_filter_match(struct perf_event *event) return evtype != ARMV8_PMUV3_PERFCTR_CHAIN; } +static void armv8pmu_brbe_filter(struct pmu_hw_events *hw_event, struct perf_event *event) +{ +} + +static void armv8pmu_brbe_enable(struct pmu_hw_events *hw_event) +{ +} + +static void armv8pmu_brbe_disable(struct pmu_hw_events *hw_event) +{ +} + +static void armv8pmu_brbe_read(struct pmu_hw_events *hw_event, struct perf_event *event) +{ +} + +static void armv8pmu_brbe_probe(struct pmu_hw_events *hw_event) +{ +} + +static void armv8pmu_brbe_reset(struct pmu_hw_events *hw_event) +{ +} + +static bool armv8pmu_brbe_supported(struct perf_event *event) +{ + return false; +} + static void armv8pmu_reset(void *info) { struct arm_pmu *cpu_pmu = (struct arm_pmu *)info;
@@ -1257,6 +1286,13 @@ static int armv8_pmu_init(struct arm_pmu *cpu_pmu, char *name, cpu_pmu->pmu.event_idx = armv8pmu_user_event_idx; + cpu_pmu->brbe_filter = armv8pmu_brbe_filter; + cpu_pmu->brbe_enable = armv8pmu_brbe_enable; + cpu_pmu->brbe_disable = armv8pmu_brbe_disable; + cpu_pmu->brbe_read = armv8pmu_brbe_read; + cpu_pmu->brbe_probe = armv8pmu_brbe_probe; + cpu_pmu->brbe_reset = armv8pmu_brbe_reset; + cpu_pmu->brbe_supported = armv8pmu_brbe_supported; cpu_pmu->name = name; cpu_pmu->map_event = map_event; cpu_pmu->attr_groups[ARMPMU_ATTR_GROUP_EVENTS] = events ?
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index 0407a38b470a..3d427ac0ca45 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h@@ -100,6 +100,27 @@ struct arm_pmu { void (*reset)(void *); int (*map_event)(struct perf_event *event); int (*filter_match)(struct perf_event *event); + + /* Convert perf event filters into BRBE HW filters */ + void (*brbe_filter)(struct pmu_hw_events *hw_events, struct perf_event *event); + + /* Probe BRBE HW and capture its attributes */ + void (*brbe_probe)(struct pmu_hw_events *hw_events); + + /* Enable BRBE HW with a given config */ + void (*brbe_enable)(struct pmu_hw_events *hw_events); + + /* Disable BRBE HW */ + void (*brbe_disable)(struct pmu_hw_events *hw_events); + + /* Process BRBE buffer for captured branch records */ + void (*brbe_read)(struct pmu_hw_events *hw_events, struct perf_event *event); + + /* Reset BRBE buffer */ + void (*brbe_reset)(struct pmu_hw_events *hw_events); + + /* Check whether BRBE is supported */ + bool (*brbe_supported)(struct perf_event *event); int num_events; bool secure_access; /* 32-bit ARM only */ #define ARMV8_PMUV3_MAX_COMMON_EVENTS 0x40
--
2.25.1
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