ACPI: CPPC: add paired FFH feedback-counter read hook

Browse source

cppc_get_perf_ctrs() reads the delivered and reference performance
counters one at a time.

Allow architectures to provide both FFH feedback counters in one
operation when that either narrows the sampling window or avoids extra
cross-CPU reads. Add a small FFH-specific hook for that case and fall
back to the existing per-register reads when unsupported.

Tested-by: Sumit Gupta <sumitg@nvidia.com>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Tested-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Reviewed-by: Vanshidhar Konda <vanshikonda@os.amperecomputing.com>
Signed-off-by: Pengjie Zhang <zhangpengjie2@huawei.com>
Acked-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

...

This commit is contained in:

Pengjie Zhang 2026-07-08 16:28:17 +08:00 • committed by Will Deacon

parent a13c140cc2

commit 9aa7df5205

2 changed files with 52 additions and 5 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

50

drivers/acpi/cppc_acpi.c

View file

7

include/acpi/cppc_acpi.h

View file