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authorPu Lehui <pulehui@huawei.com>2024-03-12 02:20:53 +0100
committerPalmer Dabbelt <palmer@rivosinc.com>2024-03-26 22:09:18 +0100
commitea6873118493019474abbf57d5a800da365734df (patch)
treee9f7091a893941b07b47c536ff37bcc58a43ce1a /drivers
parentriscv: compat_vdso: install compat_vdso.so.dbg to /lib/modules/*/vdso/ (diff)
downloadlinux-ea6873118493019474abbf57d5a800da365734df.tar.xz
linux-ea6873118493019474abbf57d5a800da365734df.zip
drivers/perf: riscv: Disable PERF_SAMPLE_BRANCH_* while not supported
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 <pulehui@huawei.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240312012053.1178140-1-pulehui@huaweicloud.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/perf/riscv_pmu.c4
1 files changed, 4 insertions, 0 deletions
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) {