From 041fd5189fe066b70049e59a8046ca31ac14d4dd Mon Sep 17 00:00:00 2001 From: Pu Lehui Date: Tue, 12 Mar 2024 01:20:53 +0000 Subject: [PATCH] drivers/perf: riscv: Disable PERF_SAMPLE_BRANCH_* while not supported [ Upstream commit ea6873118493019474abbf57d5a800da365734df ] RISC-V perf driver does not yet support branch sampling. Although the specification is in the works [0], it is best to disable such events until support is available, otherwise we will get unexpected results. Due to this reason, two riscv bpf testcases get_branch_snapshot and perf_branches/perf_branches_hw fail. Link: https://github.com/riscv/riscv-control-transfer-records [0] Fixes: f5bfa23f576f ("RISC-V: Add a perf core library for pmu drivers") Signed-off-by: Pu Lehui Reviewed-by: Atish Patra Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20240312012053.1178140-1-pulehui@huaweicloud.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- drivers/perf/riscv_pmu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/perf/riscv_pmu.c b/drivers/perf/riscv_pmu.c index c78a6fd6c57f..b4efdddb2ad9 100644 --- a/drivers/perf/riscv_pmu.c +++ b/drivers/perf/riscv_pmu.c @@ -313,6 +313,10 @@ static int riscv_pmu_event_init(struct perf_event *event) u64 event_config = 0; uint64_t cmask; + /* driver does not support branch stack sampling */ + if (has_branch_stack(event)) + return -EOPNOTSUPP; + hwc->flags = 0; mapped_event = rvpmu->event_map(event, &event_config); if (mapped_event < 0) {