linux-kernel - Re: [PATCH v3 08/15] coresight: etm4x: Cleanup TRCSTALLCTLR register accesses

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Date:   Tue, 12 Apr 2022 10:18:18 +0100
From:   Mike Leach <mike.leach@...aro.org>
To:     James Clark <James.Clark@....com>
Cc:     suzuki.poulose@....com, coresight@...ts.linaro.org,
        Anshuman.Khandual@....com, mathieu.poirier@...aro.org,
        leo.yan@...aro.com, Leo Yan <leo.yan@...aro.org>,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 08/15] coresight: etm4x: Cleanup TRCSTALLCTLR register accesses

On Fri, 4 Mar 2022 at 17:19, James Clark <james.clark@....com> wrote:
>
> This is a no-op change for style and consistency and has no effect on
> the binary output by the compiler. In sysreg.h fields are defined as
> the register name followed by the field name and then _MASK. This
> allows for grepping for fields by name rather than using magic numbers.
>
> Signed-off-by: James Clark <james.clark@....com>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 12 ++++++------
>  drivers/hwtracing/coresight/coresight-etm4x.h       |  4 ++++
>  2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index 2d29e9daf515..cd24590ea38a 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -397,22 +397,22 @@ static ssize_t mode_store(struct device *dev,
>
>         /* bit[8], Instruction stall bit */
>         if ((config->mode & ETM_MODE_ISTALL_EN) && (drvdata->stallctl == true))
> -               config->stall_ctrl |= BIT(8);
> +               config->stall_ctrl |= TRCSTALLCTLR_ISTALL;
>         else
> -               config->stall_ctrl &= ~BIT(8);
> +               config->stall_ctrl &= ~TRCSTALLCTLR_ISTALL;
>
>         /* bit[10], Prioritize instruction trace bit */
>         if (config->mode & ETM_MODE_INSTPRIO)
> -               config->stall_ctrl |= BIT(10);
> +               config->stall_ctrl |= TRCSTALLCTLR_INSTPRIORITY;
>         else
> -               config->stall_ctrl &= ~BIT(10);
> +               config->stall_ctrl &= ~TRCSTALLCTLR_INSTPRIORITY;
>
>         /* bit[13], Trace overflow prevention bit */
>         if ((config->mode & ETM_MODE_NOOVERFLOW) &&
>                 (drvdata->nooverflow == true))
> -               config->stall_ctrl |= BIT(13);
> +               config->stall_ctrl |= TRCSTALLCTLR_NOOVERFLOW;
>         else
> -               config->stall_ctrl &= ~BIT(13);
> +               config->stall_ctrl &= ~TRCSTALLCTLR_NOOVERFLOW;
>
>         /* bit[9] Start/stop logic control bit */
>         if (config->mode & ETM_MODE_VIEWINST_STARTSTOP)
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index cbba46f14ada..36934056a5dc 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -196,6 +196,10 @@
>  #define TRCEVENTCTL1R_ATB                      BIT(11)
>  #define TRCEVENTCTL1R_LPOVERRIDE               BIT(12)
>
> +#define TRCSTALLCTLR_ISTALL                    BIT(8)
> +#define TRCSTALLCTLR_INSTPRIORITY              BIT(10)
> +#define TRCSTALLCTLR_NOOVERFLOW                        BIT(13)
> +
>  /*
>   * System instructions to access ETM registers.
>   * See ETMv4.4 spec ARM IHI0064F section 4.3.6 System instructions
> --
> 2.28.0
>

Reviewed-by: Mike Leach <mike.leach@...aro.org>

-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK