This is a note to let you know that I've just added the patch titled
drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-perf-riscv-reset-the-counter-to-hpmevent-map.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e8c4641877371370976eb2462e0cce0cbbdd13c7
Author: Samuel Holland <samuel.holland@xxxxxxxxxx>
Date: Fri Jun 28 00:51:42 2024 -0700
drivers/perf: riscv: Reset the counter to hpmevent mapping while starting cpus
[ Upstream commit 7dd646cf745c34d31e7ed2a52265e9ca8308f58f ]
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@xxxxxxxxxx>
Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240628-misc_perf_fixes-v4-2-e01cfddcf035@xxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/perf/riscv_pmu_sbi.c b/drivers/perf/riscv_pmu_sbi.c
index d80b4b09152df..ae16ecb15f2d9 100644
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -611,7 +611,7 @@ 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)
