acrn-kernel/arch/x86/events
Kan Liang cc8a853c2d perf/x86/uncore: Correct the number of CHAs on EMR
commit 6f7f984fa8 upstream.

Starting from SPR, the basic uncore PMON information is retrieved from
the discovery table (resides in an MMIO space populated by BIOS). It is
called the discovery method. The existing value of the type->num_boxes
is from the discovery table.

On some SPR variants, there is a firmware bug that makes the value from the
discovery table incorrect. We use the value from the
SPR_MSR_UNC_CBO_CONFIG MSR to replace the one from the discovery table:

   38776cc45e ("perf/x86/uncore: Correct the number of CHAs on SPR")

Unfortunately, the SPR_MSR_UNC_CBO_CONFIG isn't available for the EMR
XCC (Always returns 0), but the above firmware bug doesn't impact the
EMR XCC.

Don't let the value from the MSR replace the existing value from the
discovery table.

Fixes: 38776cc45e ("perf/x86/uncore: Correct the number of CHAs on SPR")
Reported-by: Stephane Eranian <eranian@google.com>
Reported-by: Yunying Sun <yunying.sun@intel.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Yunying Sun <yunying.sun@intel.com>
Link: https://lore.kernel.org/r/20230905134248.496114-1-kan.liang@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-13 09:43:04 +02:00
..
amd perf/ibs: Fix interface via core pmu events 2023-07-19 16:21:02 +02:00
intel perf/x86/uncore: Correct the number of CHAs on EMR 2023-09-13 09:43:04 +02:00
zhaoxin
Kconfig
Makefile
core.c
msr.c
perf_event.h
perf_event_flags.h
probe.c
probe.h
rapl.c
utils.c