Re: [patch 02/13] ptp: Split out PTP_EXTTS_REQUEST ioctl code

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 20/06/2025 14:24, Thomas Gleixner wrote:
> Continue the ptp_ioctl() cleanup by splitting out the PTP_EXTTS_REQUEST
> ioctl code into a helper function. Convert to a lock guard while at it.
> 
> No functional change intended.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>   drivers/ptp/ptp_chardev.c |  105 +++++++++++++++++++++-------------------------
>   1 file changed, 50 insertions(+), 55 deletions(-)
> 
> --- a/drivers/ptp/ptp_chardev.c
> +++ b/drivers/ptp/ptp_chardev.c
> @@ -177,12 +177,57 @@ static long ptp_clock_getcaps(struct ptp
>   	return copy_to_user(arg, &caps, sizeof(caps)) ? -EFAULT : 0;
>   }
>   
> +static long ptp_extts_request(struct ptp_clock *ptp, unsigned int cmd, void __user *arg)
> +{
> +	struct ptp_clock_request req = { .type = PTP_CLK_REQ_EXTTS };
> +	struct ptp_clock_info *ops = ptp->info;
> +	unsigned int supported_extts_flags;
> +
> +	if (copy_from_user(&req.extts, arg, sizeof(req.extts)))
> +		return -EFAULT;
> +
> +	if (cmd == PTP_EXTTS_REQUEST2) {
> +		/* Tell the drivers to check the flags carefully. */
> +		req.extts.flags |= PTP_STRICT_FLAGS;
> +		/* Make sure no reserved bit is set. */
> +		if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
> +		    req.extts.rsv[0] || req.extts.rsv[1])
> +			return -EINVAL;
> +
> +		/* Ensure one of the rising/falling edge bits is set. */
> +		if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
> +		    (req.extts.flags & PTP_EXTTS_EDGES) == 0)
> +			return -EINVAL;
> +	} else {
> +		req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
> +		memset(req.extts.rsv, 0, sizeof(req.extts.rsv));
> +	}
> +
> +	if (req.extts.index >= ops->n_ext_ts)
> +		return -EINVAL;
> +
> +	supported_extts_flags = ptp->info->supported_extts_flags;
> +	/* The PTP_ENABLE_FEATURE flag is always supported. */
> +	supported_extts_flags |= PTP_ENABLE_FEATURE;
> +	/* If the driver does not support strictly checking flags, the
> +	 * PTP_RISING_EDGE and PTP_FALLING_EDGE flags are merely hints
> +	 * which are not enforced.
> +	 */
> +	if (!(supported_extts_flags & PTP_STRICT_FLAGS))
> +		supported_extts_flags |= PTP_EXTTS_EDGES;
> +	/* Reject unsupported flags */
> +	if (req.extts.flags & ~supported_extts_flags)
> +		return -EOPNOTSUPP;
> +
> +	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &ptp->pincfg_mux)
> +		return ops->enable(ops, &req, req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0);
> +}
> +
>   long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
>   	       unsigned long arg)
>   {
>   	struct ptp_clock *ptp =
>   		container_of(pccontext->clk, struct ptp_clock, clock);
> -	unsigned int i, pin_index, supported_extts_flags;
>   	struct ptp_sys_offset_extended *extoff = NULL;
>   	struct ptp_sys_offset_precise precise_offset;
>   	struct system_device_crosststamp xtstamp;
> @@ -192,6 +237,7 @@ long ptp_ioctl(struct posix_clock_contex
>   	struct ptp_system_timestamp sts;
>   	struct ptp_clock_request req;
>   	struct ptp_clock_time *pct;
> +	unsigned int i, pin_index;
>   	struct ptp_pin_desc pd;
>   	struct timespec64 ts;
>   	int enable, err = 0;
> @@ -210,60 +256,9 @@ long ptp_ioctl(struct posix_clock_contex
>   
>   	case PTP_EXTTS_REQUEST:
>   	case PTP_EXTTS_REQUEST2:
> -		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0) {
> -			err = -EACCES;
> -			break;
> -		}
> -		memset(&req, 0, sizeof(req));
> -
> -		if (copy_from_user(&req.extts, (void __user *)arg,
> -				   sizeof(req.extts))) {
> -			err = -EFAULT;
> -			break;
> -		}
> -		if (cmd == PTP_EXTTS_REQUEST2) {
> -			/* Tell the drivers to check the flags carefully. */
> -			req.extts.flags |= PTP_STRICT_FLAGS;
> -			/* Make sure no reserved bit is set. */
> -			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
> -			    req.extts.rsv[0] || req.extts.rsv[1]) {
> -				err = -EINVAL;
> -				break;
> -			}
> -			/* Ensure one of the rising/falling edge bits is set. */
> -			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
> -			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
> -				err = -EINVAL;
> -				break;
> -			}
> -		} else if (cmd == PTP_EXTTS_REQUEST) {
> -			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
> -			req.extts.rsv[0] = 0;
> -			req.extts.rsv[1] = 0;
> -		}
> -		if (req.extts.index >= ops->n_ext_ts) {
> -			err = -EINVAL;
> -			break;
> -		}
> -		supported_extts_flags = ptp->info->supported_extts_flags;
> -		/* The PTP_ENABLE_FEATURE flag is always supported. */
> -		supported_extts_flags |= PTP_ENABLE_FEATURE;
> -		/* If the driver does not support strictly checking flags, the
> -		 * PTP_RISING_EDGE and PTP_FALLING_EDGE flags are merely
> -		 * hints which are not enforced.
> -		 */
> -		if (!(supported_extts_flags & PTP_STRICT_FLAGS))
> -			supported_extts_flags |= PTP_EXTTS_EDGES;
> -		/* Reject unsupported flags */
> -		if (req.extts.flags & ~supported_extts_flags)
> -			return -EOPNOTSUPP;
> -		req.type = PTP_CLK_REQ_EXTTS;
> -		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
> -		if (mutex_lock_interruptible(&ptp->pincfg_mux))
> -			return -ERESTARTSYS;
> -		err = ops->enable(ops, &req, enable);
> -		mutex_unlock(&ptp->pincfg_mux);
> -		break;
> +		if ((pccontext->fp->f_mode & FMODE_WRITE) == 0)
> +			return -EACCES;
> +		return ptp_extts_request(ptp, cmd, argptr);
>   
>   	case PTP_PEROUT_REQUEST:
>   	case PTP_PEROUT_REQUEST2:
> 
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>