Merge patch series "SBI PMU event related fixes"

Atish Patra <atishp@rivosinc.com> says:

Here are two minor improvement/fixes in the PMU event path. The first patch
was part of the series[1]. The 2nd patch was suggested during the series
review.

While the series can only be merged once SBI v3.0 is frozen, these two
patches can be independent of SBI v3.0 and can be merged sooner. Hence, these
two patches are sent as a separate series.

* b4-shazam-merge:
  drivers/perf: riscv: Do not allow invalid raw event config
  drivers/perf: riscv: Return error for default case
  drivers/perf: riscv: Fix Platform firmware event data

Link: https://lore.kernel.org/r/20241212-pmu_event_fixes_v2-v2-0-813e8a4f5962@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: palmer-dabbelt

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

@@ -507,8 +507,7 @@ 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;
+	int ret = -ENOENT;
 
 	/*
 	 * Ensure we are finished checking standard hardware events for
@@ -528,21 +527,23 @@ 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;
+			/* Return error any bits [48-63] is set  as it is not allowed by the spec */
+			if (!(config & ~RISCV_PMU_RAW_EVENT_MASK)) {
+				*econfig = config & RISCV_PMU_RAW_EVENT_MASK;
+				ret = RISCV_PMU_RAW_EVENT_IDX;
+			}
 			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:
 			/*
@@ -551,12 +552,13 @@ 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;
+		default:
 			break;
 		}
 		break;
 	default:
-		ret = -ENOENT;
 		break;
 	}