[PATCH v6 5/8] drivers/perf: riscv: Export PMU event info function
From: Atish Patra <hidden>
Date: 2025-09-09 07:03:30
Also in:
kvm, kvm-riscv, linux-riscv, lkml
Subsystem:
arm pmu profiling and debugging, risc-v pmu drivers, the rest · Maintainers:
Will Deacon, Mark Rutland, Atish Patra, Linus Torvalds
The event mapping function can be used in event info function to find out the corresponding SBI PMU event encoding during the get_event_info function as well. Refactor and export it so that it can be invoked from kvm and internal driver. Signed-off-by: Atish Patra <redacted> Reviewed-by: Anup Patel <anup@brainfault.org> --- drivers/perf/riscv_pmu_sbi.c | 122 ++++++++++++++++++++++------------------- include/linux/perf/riscv_pmu.h | 1 + 2 files changed, 68 insertions(+), 55 deletions(-)
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index a6c479f853e1..0392900d828e 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c@@ -100,6 +100,7 @@ static unsigned int riscv_pmu_irq; /* Cache the available counters in a bitmask */ static unsigned long cmask; +static int pmu_event_find_cache(u64 config); struct sbi_pmu_event_data { union { union {
@@ -412,6 +413,71 @@ static bool pmu_sbi_ctr_is_fw(int cidx) return (info->type == SBI_PMU_CTR_TYPE_FW) ? true : false; } +int riscv_pmu_get_event_info(u32 type, u64 config, u64 *econfig) +{ + int ret = -ENOENT; + + switch (type) { + case PERF_TYPE_HARDWARE: + if (config >= PERF_COUNT_HW_MAX) + return -EINVAL; + ret = pmu_hw_event_map[config].event_idx; + break; + case PERF_TYPE_HW_CACHE: + ret = pmu_event_find_cache(config); + break; + case PERF_TYPE_RAW: + /* + * As per SBI v0.3 specification, + * -- the upper 16 bits must be unused for a hardware raw event. + * As per SBI v2.0 specification, + * -- the upper 8 bits must be unused for a hardware raw event. + * Bits 63:62 are used to distinguish between raw events + * 00 - Hardware raw event + * 10 - SBI firmware events + * 11 - Risc-V platform specific firmware event + */ + switch (config >> 62) { + case 0: + if (sbi_v3_available) { + /* Return error any bits [56-63] is set as it is not allowed by the spec */ + if (!(config & ~RISCV_PMU_RAW_EVENT_V2_MASK)) { + if (econfig) + *econfig = config & RISCV_PMU_RAW_EVENT_V2_MASK; + ret = RISCV_PMU_RAW_EVENT_V2_IDX; + } + /* Return error any bits [48-63] is set as it is not allowed by the spec */ + } else if (!(config & ~RISCV_PMU_RAW_EVENT_MASK)) { + if (econfig) + *econfig = config & RISCV_PMU_RAW_EVENT_MASK; + ret = RISCV_PMU_RAW_EVENT_IDX; + } + break; + case 2: + ret = (config & 0xFFFF) | (SBI_PMU_EVENT_TYPE_FW << 16); + break; + case 3: + /* + * For Risc-V platform specific firmware events + * Event code - 0xFFFF + * Event data - raw event encoding + */ + ret = SBI_PMU_EVENT_TYPE_FW << 16 | RISCV_PLAT_FW_EVENT; + if (econfig) + *econfig = config & RISCV_PMU_PLAT_FW_EVENT_MASK; + break; + default: + break; + } + break; + default: + break; + } + + return ret; +} +EXPORT_SYMBOL_GPL(riscv_pmu_get_event_info); + /* * Returns the counter width of a programmable counter and number of hardware * counters. As we don't support heterogeneous CPUs yet, it is okay to just
@@ -577,7 +643,6 @@ static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig) { u32 type = event->attr.type; u64 config = event->attr.config; - int ret = -ENOENT; /* * Ensure we are finished checking standard hardware events for
@@ -585,60 +650,7 @@ static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig) */ flush_work(&check_std_events_work); - switch (type) { - case PERF_TYPE_HARDWARE: - if (config >= PERF_COUNT_HW_MAX) - return -EINVAL; - ret = pmu_hw_event_map[event->attr.config].event_idx; - break; - case PERF_TYPE_HW_CACHE: - ret = pmu_event_find_cache(config); - break; - case PERF_TYPE_RAW: - /* - * As per SBI v0.3 specification, - * -- the upper 16 bits must be unused for a hardware raw event. - * As per SBI v2.0 specification, - * -- the upper 8 bits must be unused for a hardware raw event. - * Bits 63:62 are used to distinguish between raw events - * 00 - Hardware raw event - * 10 - SBI firmware events - * 11 - Risc-V platform specific firmware event - */ - - switch (config >> 62) { - case 0: - if (sbi_v3_available) { - if (!(config & ~RISCV_PMU_RAW_EVENT_V2_MASK)) { - *econfig = config & RISCV_PMU_RAW_EVENT_V2_MASK; - ret = RISCV_PMU_RAW_EVENT_V2_IDX; - } - } else if (!(config & ~RISCV_PMU_RAW_EVENT_MASK)) { - *econfig = config & RISCV_PMU_RAW_EVENT_MASK; - ret = RISCV_PMU_RAW_EVENT_IDX; - } - break; - case 2: - ret = (config & 0xFFFF) | (SBI_PMU_EVENT_TYPE_FW << 16); - break; - case 3: - /* - * For Risc-V platform specific firmware events - * Event code - 0xFFFF - * Event data - raw event encoding - */ - ret = SBI_PMU_EVENT_TYPE_FW << 16 | RISCV_PLAT_FW_EVENT; - *econfig = config & RISCV_PMU_PLAT_FW_EVENT_MASK; - break; - default: - break; - } - break; - default: - break; - } - - return ret; + return riscv_pmu_get_event_info(type, config, econfig); } static void pmu_sbi_snapshot_free(struct riscv_pmu *pmu)
diff --git a/include/linux/perf/riscv_pmu.h b/include/linux/perf/riscv_pmu.h
index 701974639ff2..f82a28040594 100644
--- a/include/linux/perf/riscv_pmu.h
+++ b/include/linux/perf/riscv_pmu.h@@ -89,6 +89,7 @@ static inline void riscv_pmu_legacy_skip_init(void) {}; struct riscv_pmu *riscv_pmu_alloc(void); #ifdef CONFIG_RISCV_PMU_SBI int riscv_pmu_get_hpm_info(u32 *hw_ctr_width, u32 *num_hw_ctr); +int riscv_pmu_get_event_info(u32 type, u64 config, u64 *econfig); #endif #endif /* CONFIG_RISCV_PMU */
--
2.43.0