[v4] riscv: Allow userspace to directly access perf counters

[PATCH v4 03/10] riscv: Make legacy counter enum match the HW numbering

Posted by Alexandre Ghiti 2 years, 7 months ago

RISCV_PMU_LEGACY_INSTRET used to be set to 1 whereas the offset of this
hardware counter from CSR_CYCLE is actually 2: make this offset match the
real hw offset so that we can directly expose those values to userspace.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
 drivers/perf/riscv_pmu_legacy.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c
index ca9e20bfc7ac..6a000abc28bb 100644
--- a/drivers/perf/riscv_pmu_legacy.c
+++ b/drivers/perf/riscv_pmu_legacy.c
@@ -13,7 +13,7 @@
 #include <linux/platform_device.h>
 
 #define RISCV_PMU_LEGACY_CYCLE		0
-#define RISCV_PMU_LEGACY_INSTRET	1
+#define RISCV_PMU_LEGACY_INSTRET	2
 
 static bool pmu_init_done;
 
-- 
2.39.2

Re: [PATCH v4 03/10] riscv: Make legacy counter enum match the HW numbering

Posted by Atish Patra 2 years, 7 months ago

On Mon, Jul 3, 2023 at 5:49 AM Alexandre Ghiti <alexghiti@rivosinc.com> wrote:
>
> RISCV_PMU_LEGACY_INSTRET used to be set to 1 whereas the offset of this
> hardware counter from CSR_CYCLE is actually 2: make this offset match the
> real hw offset so that we can directly expose those values to userspace.
>
> Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> ---
>  drivers/perf/riscv_pmu_legacy.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c
> index ca9e20bfc7ac..6a000abc28bb 100644
> --- a/drivers/perf/riscv_pmu_legacy.c
> +++ b/drivers/perf/riscv_pmu_legacy.c
> @@ -13,7 +13,7 @@
>  #include <linux/platform_device.h>
>
>  #define RISCV_PMU_LEGACY_CYCLE         0
> -#define RISCV_PMU_LEGACY_INSTRET       1
> +#define RISCV_PMU_LEGACY_INSTRET       2
>
>  static bool pmu_init_done;
>
> --
> 2.39.2
>

Reviewed-by: Atish Patra <atishp@rivosinc.com>

-- 
Regards,
Atish