can: bittiming: can_changelink() pass extack down callstack

This is a preparation patch.

In order to pass warning/error messages during netlink calls back to
user space, pass the extack struct down the callstack of
can_changelink(), the actual error messages will be added in the
following ptaches.

Link: https://lore.kernel.org/all/20230202110854.2318594-10-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/dev/bittiming.c

@@ -12,7 +12,8 @@
  * file linux/can/netlink.h.
  */
 static int can_fixup_bittiming(const struct net_device *dev, struct can_bittiming *bt,
-			       const struct can_bittiming_const *btc)
+			       const struct can_bittiming_const *btc,
+			       struct netlink_ext_ack *extack)
 {
 	const struct can_priv *priv = netdev_priv(dev);
 	unsigned int tseg1;
@@ -50,7 +51,8 @@ static int can_fixup_bittiming(const struct net_device *dev, struct can_bittimin
 static int
 can_validate_bitrate(const struct net_device *dev, const struct can_bittiming *bt,
 		     const u32 *bitrate_const,
-		     const unsigned int bitrate_const_cnt)
+		     const unsigned int bitrate_const_cnt,
+		     struct netlink_ext_ack *extack)
 {
 	unsigned int i;
 
@@ -65,20 +67,21 @@ can_validate_bitrate(const struct net_device *dev, const struct can_bittiming *b
 int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
 		      const struct can_bittiming_const *btc,
 		      const u32 *bitrate_const,
-		      const unsigned int bitrate_const_cnt)
+		      const unsigned int bitrate_const_cnt,
+		      struct netlink_ext_ack *extack)
 {
 	/* Depending on the given can_bittiming parameter structure the CAN
 	 * timing parameters are calculated based on the provided bitrate OR
 	 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
 	 * provided directly which are then checked and fixed up.
 	 */
 	if (!bt->tq && bt->bitrate && btc)
-		return can_calc_bittiming(dev, bt, btc);
+		return can_calc_bittiming(dev, bt, btc, extack);
 	if (bt->tq && !bt->bitrate && btc)
-		return can_fixup_bittiming(dev, bt, btc);
+		return can_fixup_bittiming(dev, bt, btc, extack);
 	if (!bt->tq && bt->bitrate && bitrate_const)
 		return can_validate_bitrate(dev, bt, bitrate_const,
-					    bitrate_const_cnt);
+					    bitrate_const_cnt, extack);
 
 	return -EINVAL;
 }

drivers/net/can/dev/calc_bittiming.c

@@ -63,7 +63,7 @@ can_update_sample_point(const struct can_bittiming_const *btc,
 }
 
 int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt,
-		       const struct can_bittiming_const *btc)
+		       const struct can_bittiming_const *btc, struct netlink_ext_ack *extack)
 {
 	struct can_priv *priv = netdev_priv(dev);
 	unsigned int bitrate;			/* current bitrate */

drivers/net/can/dev/netlink.c

@@ -215,7 +215,8 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 		err = can_get_bittiming(dev, &bt,
 					priv->bittiming_const,
 					priv->bitrate_const,
-					priv->bitrate_const_cnt);
+					priv->bitrate_const_cnt,
+					extack);
 		if (err)
 			return err;
 
@@ -320,7 +321,8 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 		err = can_get_bittiming(dev, &dbt,
 					priv->data_bittiming_const,
 					priv->data_bitrate_const,
-					priv->data_bitrate_const_cnt);
+					priv->data_bitrate_const_cnt,
+					extack);
 		if (err)
 			return err;
 

include/linux/can/bittiming.h

@@ -116,7 +116,7 @@ struct can_tdc_const {
 
 #ifdef CONFIG_CAN_CALC_BITTIMING
 int can_calc_bittiming(const struct net_device *dev, struct can_bittiming *bt,
-		       const struct can_bittiming_const *btc);
+		       const struct can_bittiming_const *btc, struct netlink_ext_ack *extack);
 
 void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
 		   const struct can_bittiming *dbt,
@@ -141,7 +141,8 @@ can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
 int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
 		      const struct can_bittiming_const *btc,
 		      const u32 *bitrate_const,
-		      const unsigned int bitrate_const_cnt);
+		      const unsigned int bitrate_const_cnt,
+		      struct netlink_ext_ack *extack);
 
 /*
  * can_bit_time() - Duration of one bit