[patch V2 02/13] ptp: Split out PTP_EXTTS_REQUEST ioctl code

[Thomas Gleixner <tglx@linutronix.de>]

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>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

---
 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: