[PATCH v5 0/2] perf/x86/amd: Fix for LBR Freeze

From: Sandipan Das
Date: Mon Mar 25 2024 - 09:28:20 EST


Contains a fix for usage of LBR Freeze.

Previous versions can be found at:
v4: https://lore.kernel.org/all/cover.1710836172.git.sandipan.das@xxxxxxx/
v3: https://lore.kernel.org/all/cover.1706526029.git.sandipan.das@xxxxxxx/
v2: https://lore.kernel.org/all/cover.1704103399.git.sandipan.das@xxxxxxx/
v1: https://lore.kernel.org/all/cover.1702833179.git.sandipan.das@xxxxxxx/

Changes in v5:
- Restore previously moved scattered bits and instead create a new
Linux-defined feature word for new scattered bits as suggested by
Boris and Ingo.

Changes in v4:
- Move scattered feature bits from CPUID 0x80000022[EAX] to a dedicated
word as suggested by Ingo.
- Remove patches that have been merged (patch 2 and 3 from v3).

Changes in v3:
- As suggested by Boris, update the commit message of the first patch
with the reason behind making the LBR and PMC Freeze feature bit
visible in /proc/cpuinfo.

Changes in v2:
- Make the LBR and PMC Freeze feature bit visible in /proc/cpuinfo. As
suggested by Stephane, this will be useful to determine if it is
feasible to perform kernel FDO on a system.

Sandipan Das (2):
x86/cpufeatures: Add new word for scattered features
perf/x86/amd/lbr: Use freeze based on availability

arch/x86/events/amd/core.c | 4 ++--
arch/x86/events/amd/lbr.c | 16 ++++++++++------
arch/x86/include/asm/cpufeature.h | 6 ++++--
arch/x86/include/asm/cpufeatures.h | 10 +++++++++-
arch/x86/include/asm/disabled-features.h | 3 ++-
arch/x86/include/asm/required-features.h | 3 ++-
arch/x86/kernel/cpu/scattered.c | 1 +
7 files changed, 30 insertions(+), 13 deletions(-)

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2.34.1