Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+11
-1
+11
-1
arch/x86/events/intel/uncore_snbep.c
+11
-1
arch/x86/events/intel/uncore_snbep.c
···
6474
6474
6475
6475
type = uncore_find_type_by_id(uncore_msr_uncores, UNCORE_SPR_CHA);
6476
6476
if (type) {
6477
+
/*
6478
+
* The value from the discovery table (stored in the type->num_boxes
6479
+
* of UNCORE_SPR_CHA) is incorrect on some SPR variants because of a
6480
+
* firmware bug. Using the value from SPR_MSR_UNC_CBO_CONFIG to replace it.
6481
+
*/
6477
6482
rdmsrl(SPR_MSR_UNC_CBO_CONFIG, num_cbo);
6478
-
type->num_boxes = num_cbo;
6483
+
/*
6484
+
* The MSR doesn't work on the EMR XCC, but the firmware bug doesn't impact
6485
+
* the EMR XCC. Don't let the value from the MSR replace the existing value.
6486
+
*/
6487
+
if (num_cbo)
6488
+
type->num_boxes = num_cbo;
6479
6489
}
6480
6490
spr_uncore_iio_free_running.num_boxes = uncore_type_max_boxes(uncore_msr_uncores, UNCORE_SPR_IIO);
6481
6491
}