linux-kernel - Re: [PATCH v2 03/10] riscv: Make legacy counter enum match the HW numbering

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20230531-ddb2d631e152526102f41d5e@orel>
Date:   Wed, 31 May 2023 16:01:25 +0200
From:   Andrew Jones <ajones@...tanamicro.com>
To:     Alexandre Ghiti <alexghiti@...osinc.com>
Cc:     Jonathan Corbet <corbet@....net>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Ian Rogers <irogers@...gle.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Atish Patra <atishp@...shpatra.org>,
        Anup Patel <anup@...infault.org>,
        Will Deacon <will@...nel.org>, Rob Herring <robh@...nel.org>,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-perf-users@...r.kernel.org, linux-riscv@...ts.infradead.org,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 03/10] riscv: Make legacy counter enum match the HW
 numbering

On Fri, May 12, 2023 at 10:53:14AM +0200, Alexandre Ghiti 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@...osinc.com>
> ---
>  drivers/perf/riscv_pmu_legacy.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/perf/riscv_pmu_legacy.c b/drivers/perf/riscv_pmu_legacy.c
> index ca9e20bfc7ac..0d8c9d8849ee 100644
> --- a/drivers/perf/riscv_pmu_legacy.c
> +++ b/drivers/perf/riscv_pmu_legacy.c
> @@ -12,8 +12,11 @@
>  #include <linux/perf/riscv_pmu.h>
>  #include <linux/platform_device.h>
>  
> -#define RISCV_PMU_LEGACY_CYCLE		0
> -#define RISCV_PMU_LEGACY_INSTRET	1
> +enum {
> +	RISCV_PMU_LEGACY_CYCLE,
> +	RISCV_PMU_LEGACY_TIME,
> +	RISCV_PMU_LEGACY_INSTRET
> +};

I guess this doesn't hurt, since these are just indices internal to this
driver, but it's a bit odd to also have a RISCV_PMU_LEGACY_TIME, when
the driver is only for cycle and instret, as its Kconfig help text says.

Thanks,
drew