Align the PMU extension implementation with the error codes required
by the SBI v3.0 specification, chapter 11:
- sbi_pmu_counter_start and sbi_pmu_counter_stop (secs 11.9-11.10,
tables 39-42): the start_flags/stop_flags bits 2:(XLEN-1) are
reserved and must be zero, so return SBI_ERR_INVALID_PARAM when any
reserved flag bit is set. Introduce SBI_PMU_START_FLAGS_MASK and
SBI_PMU_STOP_FLAGS_MASK for the valid bits of each function.
- sbi_pmu_counter_start and sbi_pmu_counter_stop (tables 40 and 42):
return SBI_ERR_ALREADY_STARTED / SBI_ERR_ALREADY_STOPPED when the
set of counters includes a counter which is already started or
stopped, instead of ignoring the error returned for each counter.
- sbi_pmu_event_get_info (sec 11.14, table 47): the output word must
indicate whether the event is supported, but firmware events were
only matched against the hardware event map and were always
reported as unsupported. Report a validated firmware event as
supported.
Signed-off-by: David E. Garcia Porras <david.garcia@aheadcomputing.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20260818210023.466462-4-david.garcia@aheadcomputing.com
Signed-off-by: Anup Patel <anup@brainfault.org>