drivers/perf: riscv: Fix Platform firmware event data

Platform firmware event data field is allowed to be 62 bits for
Linux as uppper most two bits are reserved to indicate SBI fw or
platform specific firmware events.
However, the event data field is masked as per the hardware raw
event mask which is not correct.

Fix the platform firmware event data field with proper mask.

Fixes: f0c9363 ("perf/riscv-sbi: Add platform specific firmware event handling")

Signed-off-by: Atish Patra <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

Author: atishp04

arch/riscv/include/asm/sbi.h

@@ -159,6 +159,7 @@ struct riscv_pmu_snapshot_data {
 };
 
 #define RISCV_PMU_RAW_EVENT_MASK GENMASK_ULL(47, 0)
+#define RISCV_PMU_PLAT_FW_EVENT_MASK GENMASK_ULL(61, 0)
 #define RISCV_PMU_RAW_EVENT_IDX 0x20000
 #define RISCV_PLAT_FW_EVENT	0xFFFF
 

drivers/perf/riscv_pmu_sbi.c

@@ -507,7 +507,6 @@ static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
 {
 	u32 type = event->attr.type;
 	u64 config = event->attr.config;
-	u64 raw_config_val;
 	int ret;
 
 	/*
@@ -528,21 +527,20 @@ static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
 	case PERF_TYPE_RAW:
 		/*
 		 * As per SBI specification, the upper 16 bits must be unused
-		 * for a raw event.
+		 * 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
 		 */
-		raw_config_val = config & RISCV_PMU_RAW_EVENT_MASK;
+
 		switch (config >> 62) {
 		case 0:
 			ret = RISCV_PMU_RAW_EVENT_IDX;
-			*econfig = raw_config_val;
+			*econfig = config & RISCV_PMU_RAW_EVENT_MASK;
 			break;
 		case 2:
-			ret = (raw_config_val & 0xFFFF) |
-				(SBI_PMU_EVENT_TYPE_FW << 16);
+			ret = (config & 0xFFFF) | (SBI_PMU_EVENT_TYPE_FW << 16);
 			break;
 		case 3:
 			/*
@@ -551,7 +549,7 @@ static int pmu_sbi_event_map(struct perf_event *event, u64 *econfig)
 			 * Event data - raw event encoding
 			 */
 			ret = SBI_PMU_EVENT_TYPE_FW << 16 | RISCV_PLAT_FW_EVENT;
-			*econfig = raw_config_val;
+			*econfig = config & RISCV_PMU_PLAT_FW_EVENT_MASK;
 			break;
 		}
 		break;