[PATCH v4 0/2] perf/arm-cmn: Add workarounds for CMN-S3 on Graviton5
Aviv Bakal
avivb at amazon.com
Sun May 31 04:04:45 PDT 2026
This series adds support for Graviton5's customised CMN-S3 which has
zeroed discovery registers.
Patch 1 is based on Robin's suggestion [1] to move the DTM index and
watchpoint bitmaps out of hw_perf_event into separate allocations,
removing the size constraint that prevented increasing CMN_MAX_DIMENSION.
Two fixes were applied on top: the kzalloc size now accounts for
sizeof(u64), and bitmap_zero() is used instead of a raw memset for
wp_idx.
Patch 2 adds the Graviton5 workarounds.
[1] https://lore.kernel.org/all/c1d27212-8e2b-4820-bee6-ad7e7de81238@arm.com/
Changes since v3:
- Replace patch 1/2 with Robin's approach: dynamically allocate
dtm_idx and wp_idx instead of moving the struct into perf_event.h
Changes since v2:
- Revert DTC logical ID assignment back to xp->logid (per Robin's
review)
Aviv Bakal (2):
perf/arm-cmn: Move DTM index data out of hw_perf_event
perf/arm-cmn: Add workarounds for CMN-S3 on Graviton5
drivers/perf/arm-cmn.c | 121 ++++++++++++++++++++++++++++++-----------
1 file changed, 90 insertions(+), 31 deletions(-)
--
2.47.3
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