lib: sbi: Fix counter index calculation for SBI_PMU_CFG_FLAG_SKIP_MATCH

As per the SBI specification, we should "unconditionally select the first
counter from the set of counters specified by the counter_idx_base and
counter_idx_mask", so implement this behaviour.

Suggested-by: Atish Patra <atishp@atishpatra.org>
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
This commit is contained in:
Alexandre Ghiti 2023-04-13 16:02:19 +02:00 committed by Anup Patel
parent bdb3c42bca
commit 674e0199b2

View file

@ -736,10 +736,15 @@ int sbi_pmu_ctr_cfg_match(unsigned long cidx_base, unsigned long cidx_mask,
/* The caller wants to skip the match because it already knows the
* counter idx for the given event. Verify that the counter idx
* is still valid.
* As per the specification, we should "unconditionally select
* the first counter from the set of counters specified by the
* counter_idx_base and counter_idx_mask".
*/
if (active_events[hartid][cidx_base] == SBI_PMU_EVENT_IDX_INVALID)
unsigned long cidx_first = cidx_base + sbi_ffs(cidx_mask);
if (active_events[hartid][cidx_first] == SBI_PMU_EVENT_IDX_INVALID)
return SBI_EINVAL;
ctr_idx = cidx_base;
ctr_idx = cidx_first;
goto skip_match;
}