drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus

SiFiveHolland · palmer-dabbelt · commit 7dd646cf745c · 2024-07-03T12:56:21.000-07:00
Currently, we stop all the counters while a new cpu is brought online. However, the hpmevent to counter mappings are not reset. The firmware may have some stale encoding in their mapping structure which may lead to undesirable results. We have not encountered such scenario though. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240628-misc_perf_fixes-v4-2-e01cfddcf035@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
@@ -762,7 +762,7 @@ static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)
 	 * which may include counters that are not enabled yet.
 	 */
 	sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,
-		  0, pmu->cmask, 0, 0, 0, 0);
+		  0, pmu->cmask, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);
 }
 
 static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)

Original file line number	Diff line number	Diff line change
`@@ -762,7 +762,7 @@ static inline void pmu_sbi_stop_all(struct riscv_pmu *pmu)`
`762`	`762`	`* which may include counters that are not enabled yet.`
`763`	`763`	`*/`
`764`	`764`	`sbi_ecall(SBI_EXT_PMU, SBI_EXT_PMU_COUNTER_STOP,`
`765`		`- 0, pmu->cmask, 0, 0, 0, 0);`
	`765`	`+ 0, pmu->cmask, SBI_PMU_STOP_FLAG_RESET, 0, 0, 0);`
`766`	`766`	`}`
`767`	`767`
`768`	`768`	`static inline void pmu_sbi_stop_hw_ctrs(struct riscv_pmu *pmu)`