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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-10-19 01:34:23 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-10-20 22:40:20 +1100 |
| commit | ea142e590aec55ba40c5affb4d49e68c713c63dc (patch) | |
| tree | 44dc69807c481f9b566a48b2f03e711b48dc742d /arch/powerpc | |
| parent | f01b0edd562ef5a05bae31fe3a296721f89af7d9 (diff) | |
| download | linux-ea142e590aec55ba40c5affb4d49e68c713c63dc.tar.gz linux-ea142e590aec55ba40c5affb4d49e68c713c63dc.tar.bz2 linux-ea142e590aec55ba40c5affb4d49e68c713c63dc.zip | |
powerpc/perf: Fix disabling BHRB and instruction sampling
When the PMU is disabled, MMCRA is not updated to disable BHRB and
instruction sampling. This can lead to those features remaining enabled,
which can slow down a real or emulated CPU.
Fixes: 1cade527f6e9 ("powerpc/perf: BHRB control to disable BHRB logic when not used")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231018153423.298373-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/perf/core-book3s.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 8c1f7def596e..10b946e9c6e7 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -1371,8 +1371,7 @@ static void power_pmu_disable(struct pmu *pmu) /* * Disable instruction sampling if it was enabled */ - if (cpuhw->mmcr.mmcra & MMCRA_SAMPLE_ENABLE) - val &= ~MMCRA_SAMPLE_ENABLE; + val &= ~MMCRA_SAMPLE_ENABLE; /* Disable BHRB via mmcra (BHRBRD) for p10 */ if (ppmu->flags & PPMU_ARCH_31) @@ -1383,7 +1382,7 @@ static void power_pmu_disable(struct pmu *pmu) * instruction sampling or BHRB. */ if (val != mmcra) { - mtspr(SPRN_MMCRA, mmcra); + mtspr(SPRN_MMCRA, val); mb(); isync(); } |