drivers/perf: riscv: Export PMU event info function

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 <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Acked-by: Paul Walmsley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Anup Patel <[email protected]>

Author: atishp04

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
@@ -577,68 +643,14 @@ 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
 	 * validity before allowing userspace to configure any events.
 	 */
 	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)

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 */