linux-kernel - Re: [RFT PATCH v2 03/10] drivers: qcom: rpmh-rsc: Fold tcs_ctrl

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]

Date:   Wed, 1 Apr 2020 13:47:55 +0530
From:   Maulik Shah <mkshah@...eaurora.org>
To:     Douglas Anderson <dianders@...omium.org>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     mka@...omium.org, Rajendra Nayak <rnayak@...eaurora.org>,
        evgreen@...omium.org, Lina Iyer <ilina@...eaurora.org>,
        swboyd@...omium.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [RFT PATCH v2 03/10] drivers: qcom: rpmh-rsc: Fold
 tcs_ctrl_write() into its single caller

Hi,

Tested-by: Maulik Shah <mkshah@...eaurora.org>

Thanks,
Maulik

On 3/12/2020 4:43 AM, Douglas Anderson wrote:
> I was trying to write documentation for the functions in rpmh-rsc and
> I got to tcs_ctrl_write().  The documentation for the function would
> have been: "This is the core of rpmh_rsc_write_ctrl_data(); all the
> caller does is error-check and then call this".
>
> Having the error checks in a separate function doesn't help for
> anything since:
> - There are no other callers that need to bypass the error checks.
> - It's less documenting.  When I read tcs_ctrl_write() I kept
>    wondering if I need to handle cases other than ACTIVE_ONLY or cases
>    with more commands than could fit in a TCS.  This is obvious when
>    the error checks and code are together.
> - The function just isn't that long, so there's no problem
>    understanding the combined function.
>
> Things were even more confusing because the two functions names didn't
> make obvious (at least to me) their relationship.
>
> Simplify by folding one function into the other.
>
> Signed-off-by: Douglas Anderson <dianders@...omium.org>
> Reviewed-by: Maulik Shah <mkshah@...eaurora.org>
> ---
>
> Changes in v2: None
>
>   drivers/soc/qcom/rpmh-rsc.c | 39 ++++++++++++++++---------------------
>   1 file changed, 17 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> index 02c8e0ffbbe4..799847b08038 100644
> --- a/drivers/soc/qcom/rpmh-rsc.c
> +++ b/drivers/soc/qcom/rpmh-rsc.c
> @@ -550,27 +550,6 @@ static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg,
>   	return 0;
>   }
>   
> -static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg)
> -{
> -	struct tcs_group *tcs;
> -	int tcs_id = 0, cmd_id = 0;
> -	unsigned long flags;
> -	int ret;
> -
> -	tcs = get_tcs_for_msg(drv, msg);
> -	if (IS_ERR(tcs))
> -		return PTR_ERR(tcs);
> -
> -	spin_lock_irqsave(&tcs->lock, flags);
> -	/* find the TCS id and the command in the TCS to write to */
> -	ret = find_slots(tcs, msg, &tcs_id, &cmd_id);
> -	if (!ret)
> -		__tcs_buffer_write(drv, tcs_id, cmd_id, msg);
> -	spin_unlock_irqrestore(&tcs->lock, flags);
> -
> -	return ret;
> -}
> -
>   /**
>    * rpmh_rsc_write_ctrl_data: Write request to the controller
>    *
> @@ -581,6 +560,11 @@ static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg)
>    */
>   int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
>   {
> +	struct tcs_group *tcs;
> +	int tcs_id = 0, cmd_id = 0;
> +	unsigned long flags;
> +	int ret;
> +
>   	if (!msg || !msg->cmds || !msg->num_cmds ||
>   	    msg->num_cmds > MAX_RPMH_PAYLOAD) {
>   		pr_err("Payload error\n");
> @@ -591,7 +575,18 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
>   	if (msg->state == RPMH_ACTIVE_ONLY_STATE)
>   		return -EINVAL;
>   
> -	return tcs_ctrl_write(drv, msg);
> +	tcs = get_tcs_for_msg(drv, msg);
> +	if (IS_ERR(tcs))
> +		return PTR_ERR(tcs);
> +
> +	spin_lock_irqsave(&tcs->lock, flags);
> +	/* find the TCS id and the command in the TCS to write to */
> +	ret = find_slots(tcs, msg, &tcs_id, &cmd_id);
> +	if (!ret)
> +		__tcs_buffer_write(drv, tcs_id, cmd_id, msg);
> +	spin_unlock_irqrestore(&tcs->lock, flags);
> +
> +	return ret;
>   }
>   
>   static int rpmh_probe_tcs_config(struct platform_device *pdev,

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation