drivers: perf: added capabilities for legacy PMU

[ Upstream commit 65730fe ]

Added the PERF_PMU_CAP_NO_INTERRUPT flag because the legacy pmu driver
does not provide sampling capabilities

Added the PERF_PMU_CAP_NO_EXCLUDE flag because the legacy pmu driver
does not provide the ability to disable counter incrementation in
different privilege modes

Suggested-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Vadim Shakirov <vadim.shakirov@syntacore.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Fixes: 9b3e150 ("RISC-V: Add a simple platform driver for RISC-V  legacy perf")
Link: https://lore.kernel.org/r/20240227170002.188671-2-vadim.shakirov@syntacore.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/perf/riscv_pmu_legacy.c

@@ -117,6 +117,8 @@ static void pmu_legacy_init(struct riscv_pmu *pmu)
 	pmu->event_mapped = pmu_legacy_event_mapped;
 	pmu->event_unmapped = pmu_legacy_event_unmapped;
 	pmu->csr_index = pmu_legacy_csr_index;
+	pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+	pmu->pmu.capabilities |= PERF_PMU_CAP_NO_EXCLUDE;
 
 	perf_pmu_register(&pmu->pmu, "cpu", PERF_TYPE_RAW);
 }