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

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>

0 files changed, 0 insertions, 0 deletions