diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-10 10:34:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-09-10 10:34:46 -0700 |
| commit | e79dbf03d87b2d9978d76ddc1c06424b07b215ad (patch) | |
| tree | d806ba91d1843cd29a97beaf2fb5e587ecc677e1 /arch | |
| parent | 535a265d7f0dd50d8c3a4f8b4f3a452d56bd160f (diff) | |
| parent | 6f7f984fa85b305799076a1bcec941b9377587de (diff) | |
Merge tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf event fix from Ingo Molnar:
"Work around a firmware bug in the uncore PMU driver, affecting certain
Intel systems"
* tag 'perf-urgent-2023-09-10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/uncore: Correct the number of CHAs on EMR
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/events/intel/uncore_snbep.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c index 4d349986f76a..8250f0f59c2b 100644 --- a/arch/x86/events/intel/uncore_snbep.c +++ b/arch/x86/events/intel/uncore_snbep.c @@ -6474,8 +6474,18 @@ void spr_uncore_cpu_init(void) type = uncore_find_type_by_id(uncore_msr_uncores, UNCORE_SPR_CHA); if (type) { + /* + * The value from the discovery table (stored in the type->num_boxes + * of UNCORE_SPR_CHA) is incorrect on some SPR variants because of a + * firmware bug. Using the value from SPR_MSR_UNC_CBO_CONFIG to replace it. + */ rdmsrl(SPR_MSR_UNC_CBO_CONFIG, num_cbo); - type->num_boxes = num_cbo; + /* + * The MSR doesn't work on the EMR XCC, but the firmware bug doesn't impact + * the EMR XCC. Don't let the value from the MSR replace the existing value. + */ + if (num_cbo) + type->num_boxes = num_cbo; } spr_uncore_iio_free_running.num_boxes = uncore_type_max_boxes(uncore_msr_uncores, UNCORE_SPR_IIO); } |