[net-next v2 00/15] can: dev: cleanup and add CAN frame length handling support

[net-next v2 00/15] can: dev: cleanup and add CAN frame length handling support

[Marc Kleine-Budde]

Hello,

this series splits the CAN driver related infrastructure into several files
(patches 1...6), followed by some cleanup patches (7, 8), and support for CAN
frame length handling (9...14). Totally unrelated is patch 15, which add
software tx timestamping.

I took the path and put the calculated frame length into the struct
can_skb_priv and extended the can_get_echo_skb() and
can_rx_offload_get_echo_skb() to optionally return the CAN frame length.

Marc

---

changes since v1:
- 04: changed copyright
- 05: add missing skb.o to Makefile
- 06: add missing netlink.o to Makefile
- 10: fix comment for CANFD_FRAME_LEN_MAX
- 12: new
- 15: new

[net-next v2 01/15] MAINTAINERS: CAN network layer: add missing header file can-ml.h

[Marc Kleine-Budde]

This patch add the can-ml.h to the list of maintained files of the CAN network
layer.

Fixes: ffd956eef69b ("can: introduce CAN midlayer private and allocate it automatically")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 54fcd5fe572d..c3091a91ebbf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3960,6 +3960,7 @@ W:	https://github.com/linux-can
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
 F:	Documentation/networking/can.rst
+F:	include/linux/can/can-ml.h
 F:	include/linux/can/core.h
 F:	include/linux/can/skb.h
 F:	include/net/netns/can.h
-- 
2.29.2

[net-next v2 02/15] can: dev: move driver related infrastructure into separate subdir

[Marc Kleine-Budde]

This patch moves the CAN driver related infrastructure into a separate subdir.
It will be split into more files in the coming patches.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/Makefile               | 7 +------
 drivers/net/can/dev/Makefile           | 7 +++++++
 drivers/net/can/{ => dev}/dev.c        | 0
 drivers/net/can/{ => dev}/rx-offload.c | 0
 4 files changed, 8 insertions(+), 6 deletions(-)
 create mode 100644 drivers/net/can/dev/Makefile
 rename drivers/net/can/{ => dev}/dev.c (100%)
 rename drivers/net/can/{ => dev}/rx-offload.c (100%)

diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index 22164300122d..a2b4463d8480 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -7,12 +7,7 @@ obj-$(CONFIG_CAN_VCAN)		+= vcan.o
 obj-$(CONFIG_CAN_VXCAN)		+= vxcan.o
 obj-$(CONFIG_CAN_SLCAN)		+= slcan.o
 
-obj-$(CONFIG_CAN_DEV)		+= can-dev.o
-can-dev-y			+= dev.o
-can-dev-y			+= rx-offload.o
-
-can-dev-$(CONFIG_CAN_LEDS)	+= led.o
-
+obj-y				+= dev/
 obj-y				+= rcar/
 obj-y				+= spi/
 obj-y				+= usb/
diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
new file mode 100644
index 000000000000..cba92e6bcf6f
--- /dev/null
+++ b/drivers/net/can/dev/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_CAN_DEV)		+= can-dev.o
+can-dev-y			+= dev.o
+can-dev-y			+= rx-offload.o
+
+can-dev-$(CONFIG_CAN_LEDS)	+= led.o
diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev/dev.c
similarity index 100%
rename from drivers/net/can/dev.c
rename to drivers/net/can/dev/dev.c
diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/dev/rx-offload.c
similarity index 100%
rename from drivers/net/can/rx-offload.c
rename to drivers/net/can/dev/rx-offload.c
-- 
2.29.2

[net-next v2 03/15] can: dev: move bittiming related code into seperate file

[Marc Kleine-Budde]

This patch moves the bittiming related code of the CAN device infrastructure
into a separate file.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 MAINTAINERS                     |   1 +
 drivers/net/can/dev/Makefile    |   1 +
 drivers/net/can/dev/bittiming.c | 261 ++++++++++++++++++++++++++++++++
 drivers/net/can/dev/dev.c       | 261 --------------------------------
 include/linux/can/bittiming.h   |  44 ++++++
 include/linux/can/dev.h         |  16 +-
 6 files changed, 308 insertions(+), 276 deletions(-)
 create mode 100644 drivers/net/can/dev/bittiming.c
 create mode 100644 include/linux/can/bittiming.h

diff --git a/MAINTAINERS b/MAINTAINERS
index c3091a91ebbf..d17662df1cd7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3943,6 +3943,7 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next.git
 F:	Documentation/devicetree/bindings/net/can/
 F:	drivers/net/can/
+F:	include/linux/can/bittiming.h
 F:	include/linux/can/dev.h
 F:	include/linux/can/led.h
 F:	include/linux/can/platform/
diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index cba92e6bcf6f..b5c6bb848d9d 100644
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_CAN_DEV)		+= can-dev.o
+can-dev-y			+= bittiming.o
 can-dev-y			+= dev.o
 can-dev-y			+= rx-offload.o
 
diff --git a/drivers/net/can/dev/bittiming.c b/drivers/net/can/dev/bittiming.c
new file mode 100644
index 000000000000..f7fe226bb395
--- /dev/null
+++ b/drivers/net/can/dev/bittiming.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/can/dev.h>
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
+
+/* Bit-timing calculation derived from:
+ *
+ * Code based on LinCAN sources and H8S2638 project
+ * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
+ * Copyright 2005      Stanislav Marek
+ * email: pisa@cmp.felk.cvut.cz
+ *
+ * Calculates proper bit-timing parameters for a specified bit-rate
+ * and sample-point, which can then be used to set the bit-timing
+ * registers of the CAN controller. You can find more information
+ * in the header file linux/can/netlink.h.
+ */
+static int
+can_update_sample_point(const struct can_bittiming_const *btc,
+			unsigned int sample_point_nominal, unsigned int tseg,
+			unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
+			unsigned int *sample_point_error_ptr)
+{
+	unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
+	unsigned int sample_point, best_sample_point = 0;
+	unsigned int tseg1, tseg2;
+	int i;
+
+	for (i = 0; i <= 1; i++) {
+		tseg2 = tseg + CAN_SYNC_SEG -
+			(sample_point_nominal * (tseg + CAN_SYNC_SEG)) /
+			1000 - i;
+		tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
+		tseg1 = tseg - tseg2;
+		if (tseg1 > btc->tseg1_max) {
+			tseg1 = btc->tseg1_max;
+			tseg2 = tseg - tseg1;
+		}
+
+		sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /
+			(tseg + CAN_SYNC_SEG);
+		sample_point_error = abs(sample_point_nominal - sample_point);
+
+		if (sample_point <= sample_point_nominal &&
+		    sample_point_error < best_sample_point_error) {
+			best_sample_point = sample_point;
+			best_sample_point_error = sample_point_error;
+			*tseg1_ptr = tseg1;
+			*tseg2_ptr = tseg2;
+		}
+	}
+
+	if (sample_point_error_ptr)
+		*sample_point_error_ptr = best_sample_point_error;
+
+	return best_sample_point;
+}
+
+int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		       const struct can_bittiming_const *btc)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	unsigned int bitrate;			/* current bitrate */
+	unsigned int bitrate_error;		/* difference between current and nominal value */
+	unsigned int best_bitrate_error = UINT_MAX;
+	unsigned int sample_point_error;	/* difference between current and nominal value */
+	unsigned int best_sample_point_error = UINT_MAX;
+	unsigned int sample_point_nominal;	/* nominal sample point */
+	unsigned int best_tseg = 0;		/* current best value for tseg */
+	unsigned int best_brp = 0;		/* current best value for brp */
+	unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
+	u64 v64;
+
+	/* Use CiA recommended sample points */
+	if (bt->sample_point) {
+		sample_point_nominal = bt->sample_point;
+	} else {
+		if (bt->bitrate > 800000)
+			sample_point_nominal = 750;
+		else if (bt->bitrate > 500000)
+			sample_point_nominal = 800;
+		else
+			sample_point_nominal = 875;
+	}
+
+	/* tseg even = round down, odd = round up */
+	for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
+	     tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
+		tsegall = CAN_SYNC_SEG + tseg / 2;
+
+		/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
+		brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
+
+		/* choose brp step which is possible in system */
+		brp = (brp / btc->brp_inc) * btc->brp_inc;
+		if (brp < btc->brp_min || brp > btc->brp_max)
+			continue;
+
+		bitrate = priv->clock.freq / (brp * tsegall);
+		bitrate_error = abs(bt->bitrate - bitrate);
+
+		/* tseg brp biterror */
+		if (bitrate_error > best_bitrate_error)
+			continue;
+
+		/* reset sample point error if we have a better bitrate */
+		if (bitrate_error < best_bitrate_error)
+			best_sample_point_error = UINT_MAX;
+
+		can_update_sample_point(btc, sample_point_nominal, tseg / 2,
+					&tseg1, &tseg2, &sample_point_error);
+		if (sample_point_error > best_sample_point_error)
+			continue;
+
+		best_sample_point_error = sample_point_error;
+		best_bitrate_error = bitrate_error;
+		best_tseg = tseg / 2;
+		best_brp = brp;
+
+		if (bitrate_error == 0 && sample_point_error == 0)
+			break;
+	}
+
+	if (best_bitrate_error) {
+		/* Error in one-tenth of a percent */
+		v64 = (u64)best_bitrate_error * 1000;
+		do_div(v64, bt->bitrate);
+		bitrate_error = (u32)v64;
+		if (bitrate_error > CAN_CALC_MAX_ERROR) {
+			netdev_err(dev,
+				   "bitrate error %d.%d%% too high\n",
+				   bitrate_error / 10, bitrate_error % 10);
+			return -EDOM;
+		}
+		netdev_warn(dev, "bitrate error %d.%d%%\n",
+			    bitrate_error / 10, bitrate_error % 10);
+	}
+
+	/* real sample point */
+	bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
+						   best_tseg, &tseg1, &tseg2,
+						   NULL);
+
+	v64 = (u64)best_brp * 1000 * 1000 * 1000;
+	do_div(v64, priv->clock.freq);
+	bt->tq = (u32)v64;
+	bt->prop_seg = tseg1 / 2;
+	bt->phase_seg1 = tseg1 - bt->prop_seg;
+	bt->phase_seg2 = tseg2;
+
+	/* check for sjw user settings */
+	if (!bt->sjw || !btc->sjw_max) {
+		bt->sjw = 1;
+	} else {
+		/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
+		if (bt->sjw > btc->sjw_max)
+			bt->sjw = btc->sjw_max;
+		/* bt->sjw must not be higher than tseg2 */
+		if (tseg2 < bt->sjw)
+			bt->sjw = tseg2;
+	}
+
+	bt->brp = best_brp;
+
+	/* real bitrate */
+	bt->bitrate = priv->clock.freq /
+		(bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2));
+
+	return 0;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+/* Checks the validity of the specified bit-timing parameters prop_seg,
+ * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
+ * prescaler value brp. You can find more information in the header
+ * file linux/can/netlink.h.
+ */
+static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
+			       const struct can_bittiming_const *btc)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	int tseg1, alltseg;
+	u64 brp64;
+
+	tseg1 = bt->prop_seg + bt->phase_seg1;
+	if (!bt->sjw)
+		bt->sjw = 1;
+	if (bt->sjw > btc->sjw_max ||
+	    tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
+	    bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
+		return -ERANGE;
+
+	brp64 = (u64)priv->clock.freq * (u64)bt->tq;
+	if (btc->brp_inc > 1)
+		do_div(brp64, btc->brp_inc);
+	brp64 += 500000000UL - 1;
+	do_div(brp64, 1000000000UL); /* the practicable BRP */
+	if (btc->brp_inc > 1)
+		brp64 *= btc->brp_inc;
+	bt->brp = (u32)brp64;
+
+	if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
+		return -EINVAL;
+
+	alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
+	bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
+	bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
+
+	return 0;
+}
+
+/* Checks the validity of predefined bitrate settings */
+static int
+can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
+		     const u32 *bitrate_const,
+		     const unsigned int bitrate_const_cnt)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	unsigned int i;
+
+	for (i = 0; i < bitrate_const_cnt; i++) {
+		if (bt->bitrate == bitrate_const[i])
+			break;
+	}
+
+	if (i >= priv->bitrate_const_cnt)
+		return -EINVAL;
+
+	return 0;
+}
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		      const struct can_bittiming_const *btc,
+		      const u32 *bitrate_const,
+		      const unsigned int bitrate_const_cnt)
+{
+	int err;
+
+	/* 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)
+		err = can_calc_bittiming(dev, bt, btc);
+	else if (bt->tq && !bt->bitrate && btc)
+		err = can_fixup_bittiming(dev, bt, btc);
+	else if (!bt->tq && bt->bitrate && bitrate_const)
+		err = can_validate_bitrate(dev, bt, bitrate_const,
+					   bitrate_const_cnt);
+	else
+		err = -EINVAL;
+
+	return err;
+}
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 3486704c8a95..1b3ab95b3fd1 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -58,267 +58,6 @@ u8 can_fd_len2dlc(u8 len)
 }
 EXPORT_SYMBOL_GPL(can_fd_len2dlc);
 
-#ifdef CONFIG_CAN_CALC_BITTIMING
-#define CAN_CALC_MAX_ERROR 50 /* in one-tenth of a percent */
-
-/* Bit-timing calculation derived from:
- *
- * Code based on LinCAN sources and H8S2638 project
- * Copyright 2004-2006 Pavel Pisa - DCE FELK CVUT cz
- * Copyright 2005      Stanislav Marek
- * email: pisa@cmp.felk.cvut.cz
- *
- * Calculates proper bit-timing parameters for a specified bit-rate
- * and sample-point, which can then be used to set the bit-timing
- * registers of the CAN controller. You can find more information
- * in the header file linux/can/netlink.h.
- */
-static int
-can_update_sample_point(const struct can_bittiming_const *btc,
-			unsigned int sample_point_nominal, unsigned int tseg,
-			unsigned int *tseg1_ptr, unsigned int *tseg2_ptr,
-			unsigned int *sample_point_error_ptr)
-{
-	unsigned int sample_point_error, best_sample_point_error = UINT_MAX;
-	unsigned int sample_point, best_sample_point = 0;
-	unsigned int tseg1, tseg2;
-	int i;
-
-	for (i = 0; i <= 1; i++) {
-		tseg2 = tseg + CAN_SYNC_SEG -
-			(sample_point_nominal * (tseg + CAN_SYNC_SEG)) /
-			1000 - i;
-		tseg2 = clamp(tseg2, btc->tseg2_min, btc->tseg2_max);
-		tseg1 = tseg - tseg2;
-		if (tseg1 > btc->tseg1_max) {
-			tseg1 = btc->tseg1_max;
-			tseg2 = tseg - tseg1;
-		}
-
-		sample_point = 1000 * (tseg + CAN_SYNC_SEG - tseg2) /
-			(tseg + CAN_SYNC_SEG);
-		sample_point_error = abs(sample_point_nominal - sample_point);
-
-		if (sample_point <= sample_point_nominal &&
-		    sample_point_error < best_sample_point_error) {
-			best_sample_point = sample_point;
-			best_sample_point_error = sample_point_error;
-			*tseg1_ptr = tseg1;
-			*tseg2_ptr = tseg2;
-		}
-	}
-
-	if (sample_point_error_ptr)
-		*sample_point_error_ptr = best_sample_point_error;
-
-	return best_sample_point;
-}
-
-static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
-			      const struct can_bittiming_const *btc)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	unsigned int bitrate;			/* current bitrate */
-	unsigned int bitrate_error;		/* difference between current and nominal value */
-	unsigned int best_bitrate_error = UINT_MAX;
-	unsigned int sample_point_error;	/* difference between current and nominal value */
-	unsigned int best_sample_point_error = UINT_MAX;
-	unsigned int sample_point_nominal;	/* nominal sample point */
-	unsigned int best_tseg = 0;		/* current best value for tseg */
-	unsigned int best_brp = 0;		/* current best value for brp */
-	unsigned int brp, tsegall, tseg, tseg1 = 0, tseg2 = 0;
-	u64 v64;
-
-	/* Use CiA recommended sample points */
-	if (bt->sample_point) {
-		sample_point_nominal = bt->sample_point;
-	} else {
-		if (bt->bitrate > 800000)
-			sample_point_nominal = 750;
-		else if (bt->bitrate > 500000)
-			sample_point_nominal = 800;
-		else
-			sample_point_nominal = 875;
-	}
-
-	/* tseg even = round down, odd = round up */
-	for (tseg = (btc->tseg1_max + btc->tseg2_max) * 2 + 1;
-	     tseg >= (btc->tseg1_min + btc->tseg2_min) * 2; tseg--) {
-		tsegall = CAN_SYNC_SEG + tseg / 2;
-
-		/* Compute all possible tseg choices (tseg=tseg1+tseg2) */
-		brp = priv->clock.freq / (tsegall * bt->bitrate) + tseg % 2;
-
-		/* choose brp step which is possible in system */
-		brp = (brp / btc->brp_inc) * btc->brp_inc;
-		if (brp < btc->brp_min || brp > btc->brp_max)
-			continue;
-
-		bitrate = priv->clock.freq / (brp * tsegall);
-		bitrate_error = abs(bt->bitrate - bitrate);
-
-		/* tseg brp biterror */
-		if (bitrate_error > best_bitrate_error)
-			continue;
-
-		/* reset sample point error if we have a better bitrate */
-		if (bitrate_error < best_bitrate_error)
-			best_sample_point_error = UINT_MAX;
-
-		can_update_sample_point(btc, sample_point_nominal, tseg / 2,
-					&tseg1, &tseg2, &sample_point_error);
-		if (sample_point_error > best_sample_point_error)
-			continue;
-
-		best_sample_point_error = sample_point_error;
-		best_bitrate_error = bitrate_error;
-		best_tseg = tseg / 2;
-		best_brp = brp;
-
-		if (bitrate_error == 0 && sample_point_error == 0)
-			break;
-	}
-
-	if (best_bitrate_error) {
-		/* Error in one-tenth of a percent */
-		v64 = (u64)best_bitrate_error * 1000;
-		do_div(v64, bt->bitrate);
-		bitrate_error = (u32)v64;
-		if (bitrate_error > CAN_CALC_MAX_ERROR) {
-			netdev_err(dev,
-				   "bitrate error %d.%d%% too high\n",
-				   bitrate_error / 10, bitrate_error % 10);
-			return -EDOM;
-		}
-		netdev_warn(dev, "bitrate error %d.%d%%\n",
-			    bitrate_error / 10, bitrate_error % 10);
-	}
-
-	/* real sample point */
-	bt->sample_point = can_update_sample_point(btc, sample_point_nominal,
-						   best_tseg, &tseg1, &tseg2,
-						   NULL);
-
-	v64 = (u64)best_brp * 1000 * 1000 * 1000;
-	do_div(v64, priv->clock.freq);
-	bt->tq = (u32)v64;
-	bt->prop_seg = tseg1 / 2;
-	bt->phase_seg1 = tseg1 - bt->prop_seg;
-	bt->phase_seg2 = tseg2;
-
-	/* check for sjw user settings */
-	if (!bt->sjw || !btc->sjw_max) {
-		bt->sjw = 1;
-	} else {
-		/* bt->sjw is at least 1 -> sanitize upper bound to sjw_max */
-		if (bt->sjw > btc->sjw_max)
-			bt->sjw = btc->sjw_max;
-		/* bt->sjw must not be higher than tseg2 */
-		if (tseg2 < bt->sjw)
-			bt->sjw = tseg2;
-	}
-
-	bt->brp = best_brp;
-
-	/* real bitrate */
-	bt->bitrate = priv->clock.freq /
-		(bt->brp * (CAN_SYNC_SEG + tseg1 + tseg2));
-
-	return 0;
-}
-#else /* !CONFIG_CAN_CALC_BITTIMING */
-static int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
-			      const struct can_bittiming_const *btc)
-{
-	netdev_err(dev, "bit-timing calculation not available\n");
-	return -EINVAL;
-}
-#endif /* CONFIG_CAN_CALC_BITTIMING */
-
-/* Checks the validity of the specified bit-timing parameters prop_seg,
- * phase_seg1, phase_seg2 and sjw and tries to determine the bitrate
- * prescaler value brp. You can find more information in the header
- * file linux/can/netlink.h.
- */
-static int can_fixup_bittiming(struct net_device *dev, struct can_bittiming *bt,
-			       const struct can_bittiming_const *btc)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	int tseg1, alltseg;
-	u64 brp64;
-
-	tseg1 = bt->prop_seg + bt->phase_seg1;
-	if (!bt->sjw)
-		bt->sjw = 1;
-	if (bt->sjw > btc->sjw_max ||
-	    tseg1 < btc->tseg1_min || tseg1 > btc->tseg1_max ||
-	    bt->phase_seg2 < btc->tseg2_min || bt->phase_seg2 > btc->tseg2_max)
-		return -ERANGE;
-
-	brp64 = (u64)priv->clock.freq * (u64)bt->tq;
-	if (btc->brp_inc > 1)
-		do_div(brp64, btc->brp_inc);
-	brp64 += 500000000UL - 1;
-	do_div(brp64, 1000000000UL); /* the practicable BRP */
-	if (btc->brp_inc > 1)
-		brp64 *= btc->brp_inc;
-	bt->brp = (u32)brp64;
-
-	if (bt->brp < btc->brp_min || bt->brp > btc->brp_max)
-		return -EINVAL;
-
-	alltseg = bt->prop_seg + bt->phase_seg1 + bt->phase_seg2 + 1;
-	bt->bitrate = priv->clock.freq / (bt->brp * alltseg);
-	bt->sample_point = ((tseg1 + 1) * 1000) / alltseg;
-
-	return 0;
-}
-
-/* Checks the validity of predefined bitrate settings */
-static int
-can_validate_bitrate(struct net_device *dev, struct can_bittiming *bt,
-		     const u32 *bitrate_const,
-		     const unsigned int bitrate_const_cnt)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	unsigned int i;
-
-	for (i = 0; i < bitrate_const_cnt; i++) {
-		if (bt->bitrate == bitrate_const[i])
-			break;
-	}
-
-	if (i >= priv->bitrate_const_cnt)
-		return -EINVAL;
-
-	return 0;
-}
-
-static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
-			     const struct can_bittiming_const *btc,
-			     const u32 *bitrate_const,
-			     const unsigned int bitrate_const_cnt)
-{
-	int err;
-
-	/* 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)
-		err = can_calc_bittiming(dev, bt, btc);
-	else if (bt->tq && !bt->bitrate && btc)
-		err = can_fixup_bittiming(dev, bt, btc);
-	else if (!bt->tq && bt->bitrate && bitrate_const)
-		err = can_validate_bitrate(dev, bt, bitrate_const,
-					   bitrate_const_cnt);
-	else
-		err = -EINVAL;
-
-	return err;
-}
-
 static void can_update_state_error_stats(struct net_device *dev,
 					 enum can_state new_state)
 {
diff --git a/include/linux/can/bittiming.h b/include/linux/can/bittiming.h
new file mode 100644
index 000000000000..707575c668f4
--- /dev/null
+++ b/include/linux/can/bittiming.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2020 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
+ */
+
+#ifndef _CAN_BITTIMING_H
+#define _CAN_BITTIMING_H
+
+#include <linux/netdevice.h>
+#include <linux/can/netlink.h>
+
+#define CAN_SYNC_SEG 1
+
+#ifdef CONFIG_CAN_CALC_BITTIMING
+int can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		       const struct can_bittiming_const *btc);
+#else /* !CONFIG_CAN_CALC_BITTIMING */
+static inline int
+can_calc_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		   const struct can_bittiming_const *btc)
+{
+	netdev_err(dev, "bit-timing calculation not available\n");
+	return -EINVAL;
+}
+#endif /* CONFIG_CAN_CALC_BITTIMING */
+
+int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt,
+		      const struct can_bittiming_const *btc,
+		      const u32 *bitrate_const,
+		      const unsigned int bitrate_const_cnt);
+
+/*
+ * can_bit_time() - Duration of one bit
+ *
+ * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
+ * additional information.
+ *
+ * Return: the number of time quanta in one bit.
+ */
+static inline unsigned int can_bit_time(const struct can_bittiming *bt)
+{
+	return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
+}
+
+#endif /* !_CAN_BITTIMING_H */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 197a79535cc2..054c3bed190b 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -15,6 +15,7 @@
 #define _CAN_DEV_H
 
 #include <linux/can.h>
+#include <linux/can/bittiming.h>
 #include <linux/can/error.h>
 #include <linux/can/led.h>
 #include <linux/can/netlink.h>
@@ -82,21 +83,6 @@ struct can_priv {
 #endif
 };
 
-#define CAN_SYNC_SEG 1
-
-/*
- * can_bit_time() - Duration of one bit
- *
- * Please refer to ISO 11898-1:2015, section 11.3.1.1 "Bit time" for
- * additional information.
- *
- * Return: the number of time quanta in one bit.
- */
-static inline unsigned int can_bit_time(const struct can_bittiming *bt)
-{
-	return CAN_SYNC_SEG + bt->prop_seg + bt->phase_seg1 + bt->phase_seg2;
-}
-
 /*
  * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
  * Classical CAN frame into a valid data length of max. 8 bytes.
-- 
2.29.2

[net-next v2 04/15] can: dev: move length related code into seperate file

[Marc Kleine-Budde]

This patch moves all CAN frame length related code of the CAN device
infrastructure into a separate file.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 MAINTAINERS                  |  1 +
 drivers/net/can/dev/Makefile |  1 +
 drivers/net/can/dev/dev.c    | 33 -------------------------
 drivers/net/can/dev/length.c | 38 ++++++++++++++++++++++++++++
 include/linux/can/dev.h      | 41 +-----------------------------
 include/linux/can/length.h   | 48 ++++++++++++++++++++++++++++++++++++
 6 files changed, 89 insertions(+), 73 deletions(-)
 create mode 100644 drivers/net/can/dev/length.c
 create mode 100644 include/linux/can/length.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d17662df1cd7..21780c4e2e71 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3946,6 +3946,7 @@ F:	drivers/net/can/
 F:	include/linux/can/bittiming.h
 F:	include/linux/can/dev.h
 F:	include/linux/can/led.h
+F:	include/linux/can/length.h
 F:	include/linux/can/platform/
 F:	include/linux/can/rx-offload.h
 F:	include/uapi/linux/can/error.h
diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index b5c6bb848d9d..5c647951e06d 100644
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -3,6 +3,7 @@
 obj-$(CONFIG_CAN_DEV)		+= can-dev.o
 can-dev-y			+= bittiming.o
 can-dev-y			+= dev.o
+can-dev-y			+= length.o
 can-dev-y			+= rx-offload.o
 
 can-dev-$(CONFIG_CAN_LEDS)	+= led.o
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 1b3ab95b3fd1..3372e99d5db7 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -25,39 +25,6 @@ MODULE_DESCRIPTION(MOD_DESC);
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
 
-/* CAN DLC to real data length conversion helpers */
-
-static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
-			     8, 12, 16, 20, 24, 32, 48, 64};
-
-/* get data length from raw data length code (DLC) */
-u8 can_fd_dlc2len(u8 dlc)
-{
-	return dlc2len[dlc & 0x0F];
-}
-EXPORT_SYMBOL_GPL(can_fd_dlc2len);
-
-static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
-			     9, 9, 9, 9,			/* 9 - 12 */
-			     10, 10, 10, 10,			/* 13 - 16 */
-			     11, 11, 11, 11,			/* 17 - 20 */
-			     12, 12, 12, 12,			/* 21 - 24 */
-			     13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
-			     14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
-			     14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
-			     15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
-			     15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */
-
-/* map the sanitized data length to an appropriate data length code */
-u8 can_fd_len2dlc(u8 len)
-{
-	if (unlikely(len > 64))
-		return 0xF;
-
-	return len2dlc[len];
-}
-EXPORT_SYMBOL_GPL(can_fd_len2dlc);
-
 static void can_update_state_error_stats(struct net_device *dev,
 					 enum can_state new_state)
 {
diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c
new file mode 100644
index 000000000000..6fe18aa23ec9
--- /dev/null
+++ b/drivers/net/can/dev/length.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2012, 2020 Oliver Hartkopp <socketcan@hartkopp.net>
+ */
+
+#include <linux/can/dev.h>
+
+/* CAN DLC to real data length conversion helpers */
+
+static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
+			     8, 12, 16, 20, 24, 32, 48, 64};
+
+/* get data length from raw data length code (DLC) */
+u8 can_fd_dlc2len(u8 dlc)
+{
+	return dlc2len[dlc & 0x0F];
+}
+EXPORT_SYMBOL_GPL(can_fd_dlc2len);
+
+static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
+			     9, 9, 9, 9,			/* 9 - 12 */
+			     10, 10, 10, 10,			/* 13 - 16 */
+			     11, 11, 11, 11,			/* 17 - 20 */
+			     12, 12, 12, 12,			/* 21 - 24 */
+			     13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
+			     14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
+			     14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
+			     15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
+			     15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_fd_len2dlc(u8 len)
+{
+	if (unlikely(len > 64))
+		return 0xF;
+
+	return len2dlc[len];
+}
+EXPORT_SYMBOL_GPL(can_fd_len2dlc);
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 054c3bed190b..d75fba1d030a 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -18,6 +18,7 @@
 #include <linux/can/bittiming.h>
 #include <linux/can/error.h>
 #include <linux/can/led.h>
+#include <linux/can/length.h>
 #include <linux/can/netlink.h>
 #include <linux/can/skb.h>
 #include <linux/netdevice.h>
@@ -83,15 +84,6 @@ struct can_priv {
 #endif
 };
 
-/*
- * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
- * Classical CAN frame into a valid data length of max. 8 bytes.
- *
- * To be used in the CAN netdriver receive path to ensure conformance with
- * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
- */
-#define can_cc_dlc2len(dlc)	(min_t(u8, (dlc), CAN_MAX_DLEN))
-
 /* Check for outgoing skbs that have not been created by the CAN subsystem */
 static inline bool can_skb_headroom_valid(struct net_device *dev,
 					  struct sk_buff *skb)
@@ -156,31 +148,6 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
 	return skb->len == CANFD_MTU;
 }
 
-/* helper to get the data length code (DLC) for Classical CAN raw DLC access */
-static inline u8 can_get_cc_dlc(const struct can_frame *cf, const u32 ctrlmode)
-{
-	/* return len8_dlc as dlc value only if all conditions apply */
-	if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) &&
-	    (cf->len == CAN_MAX_DLEN) &&
-	    (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC))
-		return cf->len8_dlc;
-
-	/* return the payload length as dlc value */
-	return cf->len;
-}
-
-/* helper to set len and len8_dlc value for Classical CAN raw DLC access */
-static inline void can_frame_set_cc_len(struct can_frame *cf, const u8 dlc,
-					const u32 ctrlmode)
-{
-	/* the caller already ensured that dlc is a value from 0 .. 15 */
-	if (ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC && dlc > CAN_MAX_DLEN)
-		cf->len8_dlc = dlc;
-
-	/* limit the payload length 'len' to CAN_MAX_DLEN */
-	cf->len = can_cc_dlc2len(dlc);
-}
-
 /* helper to define static CAN controller features at device creation time */
 static inline void can_set_static_ctrlmode(struct net_device *dev,
 					   u32 static_mode)
@@ -196,12 +163,6 @@ static inline void can_set_static_ctrlmode(struct net_device *dev,
 		dev->mtu = CANFD_MTU;
 }
 
-/* get data length from raw data length code (DLC) */
-u8 can_fd_dlc2len(u8 dlc);
-
-/* map the sanitized data length to an appropriate data length code */
-u8 can_fd_len2dlc(u8 len);
-
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 				    unsigned int txqs, unsigned int rxqs);
 #define alloc_candev(sizeof_priv, echo_skb_max) \
diff --git a/include/linux/can/length.h b/include/linux/can/length.h
new file mode 100644
index 000000000000..156b9d17969a
--- /dev/null
+++ b/include/linux/can/length.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 Oliver Hartkopp <socketcan@hartkopp.net>
+ */
+
+#ifndef _CAN_LENGTH_H
+#define _CAN_LENGTH_H
+
+/*
+ * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
+ * Classical CAN frame into a valid data length of max. 8 bytes.
+ *
+ * To be used in the CAN netdriver receive path to ensure conformance with
+ * ISO 11898-1 Chapter 8.4.2.3 (DLC field)
+ */
+#define can_cc_dlc2len(dlc)	(min_t(u8, (dlc), CAN_MAX_DLEN))
+
+/* helper to get the data length code (DLC) for Classical CAN raw DLC access */
+static inline u8 can_get_cc_dlc(const struct can_frame *cf, const u32 ctrlmode)
+{
+	/* return len8_dlc as dlc value only if all conditions apply */
+	if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) &&
+	    (cf->len == CAN_MAX_DLEN) &&
+	    (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC))
+		return cf->len8_dlc;
+
+	/* return the payload length as dlc value */
+	return cf->len;
+}
+
+/* helper to set len and len8_dlc value for Classical CAN raw DLC access */
+static inline void can_frame_set_cc_len(struct can_frame *cf, const u8 dlc,
+					const u32 ctrlmode)
+{
+	/* the caller already ensured that dlc is a value from 0 .. 15 */
+	if (ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC && dlc > CAN_MAX_DLEN)
+		cf->len8_dlc = dlc;
+
+	/* limit the payload length 'len' to CAN_MAX_DLEN */
+	cf->len = can_cc_dlc2len(dlc);
+}
+
+/* get data length from raw data length code (DLC) */
+u8 can_fd_dlc2len(u8 dlc);
+
+/* map the sanitized data length to an appropriate data length code */
+u8 can_fd_len2dlc(u8 len);
+
+#endif /* !_CAN_LENGTH_H */
-- 
2.29.2

[net-next v2 05/15] can: dev: move skb related into seperate file

[Marc Kleine-Budde]

This patch moves the skb related code of the CAN device infrastructure into a
separate file.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/dev.c | 213 ------------------------------------
 drivers/net/can/dev/skb.c | 220 ++++++++++++++++++++++++++++++++++++++
 include/linux/can/dev.h   |  76 -------------
 include/linux/can/skb.h   |  77 +++++++++++++
 4 files changed, 297 insertions(+), 289 deletions(-)
 create mode 100644 drivers/net/can/dev/skb.c

diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index 3372e99d5db7..fe71ff9ef8c9 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -132,149 +132,6 @@ void can_change_state(struct net_device *dev, struct can_frame *cf,
 }
 EXPORT_SYMBOL_GPL(can_change_state);
 
-/* Local echo of CAN messages
- *
- * CAN network devices *should* support a local echo functionality
- * (see Documentation/networking/can.rst). To test the handling of CAN
- * interfaces that do not support the local echo both driver types are
- * implemented. In the case that the driver does not support the echo
- * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
- * to perform the echo as a fallback solution.
- */
-static void can_flush_echo_skb(struct net_device *dev)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	struct net_device_stats *stats = &dev->stats;
-	int i;
-
-	for (i = 0; i < priv->echo_skb_max; i++) {
-		if (priv->echo_skb[i]) {
-			kfree_skb(priv->echo_skb[i]);
-			priv->echo_skb[i] = NULL;
-			stats->tx_dropped++;
-			stats->tx_aborted_errors++;
-		}
-	}
-}
-
-/* Put the skb on the stack to be looped backed locally lateron
- *
- * The function is typically called in the start_xmit function
- * of the device driver. The driver must protect access to
- * priv->echo_skb, if necessary.
- */
-int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
-		     unsigned int idx)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	BUG_ON(idx >= priv->echo_skb_max);
-
-	/* check flag whether this packet has to be looped back */
-	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
-	    (skb->protocol != htons(ETH_P_CAN) &&
-	     skb->protocol != htons(ETH_P_CANFD))) {
-		kfree_skb(skb);
-		return 0;
-	}
-
-	if (!priv->echo_skb[idx]) {
-		skb = can_create_echo_skb(skb);
-		if (!skb)
-			return -ENOMEM;
-
-		/* make settings for echo to reduce code in irq context */
-		skb->pkt_type = PACKET_BROADCAST;
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-		skb->dev = dev;
-
-		/* save this skb for tx interrupt echo handling */
-		priv->echo_skb[idx] = skb;
-	} else {
-		/* locking problem with netif_stop_queue() ?? */
-		netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
-		kfree_skb(skb);
-		return -EBUSY;
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(can_put_echo_skb);
-
-struct sk_buff *
-__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	if (idx >= priv->echo_skb_max) {
-		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
-			   __func__, idx, priv->echo_skb_max);
-		return NULL;
-	}
-
-	if (priv->echo_skb[idx]) {
-		/* Using "struct canfd_frame::len" for the frame
-		 * length is supported on both CAN and CANFD frames.
-		 */
-		struct sk_buff *skb = priv->echo_skb[idx];
-		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
-
-		/* get the real payload length for netdev statistics */
-		if (cf->can_id & CAN_RTR_FLAG)
-			*len_ptr = 0;
-		else
-			*len_ptr = cf->len;
-
-		priv->echo_skb[idx] = NULL;
-
-		return skb;
-	}
-
-	return NULL;
-}
-
-/* Get the skb from the stack and loop it back locally
- *
- * The function is typically called when the TX done interrupt
- * is handled in the device driver. The driver must protect
- * access to priv->echo_skb, if necessary.
- */
-unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
-{
-	struct sk_buff *skb;
-	u8 len;
-
-	skb = __can_get_echo_skb(dev, idx, &len);
-	if (!skb)
-		return 0;
-
-	skb_get(skb);
-	if (netif_rx(skb) == NET_RX_SUCCESS)
-		dev_consume_skb_any(skb);
-	else
-		dev_kfree_skb_any(skb);
-
-	return len;
-}
-EXPORT_SYMBOL_GPL(can_get_echo_skb);
-
-/* Remove the skb from the stack and free it.
- *
- * The function is typically called when TX failed.
- */
-void can_free_echo_skb(struct net_device *dev, unsigned int idx)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	BUG_ON(idx >= priv->echo_skb_max);
-
-	if (priv->echo_skb[idx]) {
-		dev_kfree_skb_any(priv->echo_skb[idx]);
-		priv->echo_skb[idx] = NULL;
-	}
-}
-EXPORT_SYMBOL_GPL(can_free_echo_skb);
-
 /* CAN device restart for bus-off recovery */
 static void can_restart(struct net_device *dev)
 {
@@ -379,76 +236,6 @@ static void can_setup(struct net_device *dev)
 	dev->features = NETIF_F_HW_CSUM;
 }
 
-struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
-{
-	struct sk_buff *skb;
-
-	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-			       sizeof(struct can_frame));
-	if (unlikely(!skb))
-		return NULL;
-
-	skb->protocol = htons(ETH_P_CAN);
-	skb->pkt_type = PACKET_BROADCAST;
-	skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-	skb_reset_mac_header(skb);
-	skb_reset_network_header(skb);
-	skb_reset_transport_header(skb);
-
-	can_skb_reserve(skb);
-	can_skb_prv(skb)->ifindex = dev->ifindex;
-	can_skb_prv(skb)->skbcnt = 0;
-
-	*cf = skb_put_zero(skb, sizeof(struct can_frame));
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_can_skb);
-
-struct sk_buff *alloc_canfd_skb(struct net_device *dev,
-				struct canfd_frame **cfd)
-{
-	struct sk_buff *skb;
-
-	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
-			       sizeof(struct canfd_frame));
-	if (unlikely(!skb))
-		return NULL;
-
-	skb->protocol = htons(ETH_P_CANFD);
-	skb->pkt_type = PACKET_BROADCAST;
-	skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-	skb_reset_mac_header(skb);
-	skb_reset_network_header(skb);
-	skb_reset_transport_header(skb);
-
-	can_skb_reserve(skb);
-	can_skb_prv(skb)->ifindex = dev->ifindex;
-	can_skb_prv(skb)->skbcnt = 0;
-
-	*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_canfd_skb);
-
-struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
-{
-	struct sk_buff *skb;
-
-	skb = alloc_can_skb(dev, cf);
-	if (unlikely(!skb))
-		return NULL;
-
-	(*cf)->can_id = CAN_ERR_FLAG;
-	(*cf)->len = CAN_ERR_DLC;
-
-	return skb;
-}
-EXPORT_SYMBOL_GPL(alloc_can_err_skb);
-
 /* Allocate and setup space for the CAN network device */
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 				    unsigned int txqs, unsigned int rxqs)
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
new file mode 100644
index 000000000000..26cd597ff771
--- /dev/null
+++ b/drivers/net/can/dev/skb.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/can/dev.h>
+
+/* Local echo of CAN messages
+ *
+ * CAN network devices *should* support a local echo functionality
+ * (see Documentation/networking/can.rst). To test the handling of CAN
+ * interfaces that do not support the local echo both driver types are
+ * implemented. In the case that the driver does not support the echo
+ * the IFF_ECHO remains clear in dev->flags. This causes the PF_CAN core
+ * to perform the echo as a fallback solution.
+ */
+void can_flush_echo_skb(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct net_device_stats *stats = &dev->stats;
+	int i;
+
+	for (i = 0; i < priv->echo_skb_max; i++) {
+		if (priv->echo_skb[i]) {
+			kfree_skb(priv->echo_skb[i]);
+			priv->echo_skb[i] = NULL;
+			stats->tx_dropped++;
+			stats->tx_aborted_errors++;
+		}
+	}
+}
+
+/* Put the skb on the stack to be looped backed locally lateron
+ *
+ * The function is typically called in the start_xmit function
+ * of the device driver. The driver must protect access to
+ * priv->echo_skb, if necessary.
+ */
+int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
+		     unsigned int idx)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	BUG_ON(idx >= priv->echo_skb_max);
+
+	/* check flag whether this packet has to be looped back */
+	if (!(dev->flags & IFF_ECHO) || skb->pkt_type != PACKET_LOOPBACK ||
+	    (skb->protocol != htons(ETH_P_CAN) &&
+	     skb->protocol != htons(ETH_P_CANFD))) {
+		kfree_skb(skb);
+		return 0;
+	}
+
+	if (!priv->echo_skb[idx]) {
+		skb = can_create_echo_skb(skb);
+		if (!skb)
+			return -ENOMEM;
+
+		/* make settings for echo to reduce code in irq context */
+		skb->pkt_type = PACKET_BROADCAST;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		skb->dev = dev;
+
+		/* save this skb for tx interrupt echo handling */
+		priv->echo_skb[idx] = skb;
+	} else {
+		/* locking problem with netif_stop_queue() ?? */
+		netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx);
+		kfree_skb(skb);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_put_echo_skb);
+
+struct sk_buff *
+__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (idx >= priv->echo_skb_max) {
+		netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n",
+			   __func__, idx, priv->echo_skb_max);
+		return NULL;
+	}
+
+	if (priv->echo_skb[idx]) {
+		/* Using "struct canfd_frame::len" for the frame
+		 * length is supported on both CAN and CANFD frames.
+		 */
+		struct sk_buff *skb = priv->echo_skb[idx];
+		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+
+		/* get the real payload length for netdev statistics */
+		if (cf->can_id & CAN_RTR_FLAG)
+			*len_ptr = 0;
+		else
+			*len_ptr = cf->len;
+
+		priv->echo_skb[idx] = NULL;
+
+		return skb;
+	}
+
+	return NULL;
+}
+
+/* Get the skb from the stack and loop it back locally
+ *
+ * The function is typically called when the TX done interrupt
+ * is handled in the device driver. The driver must protect
+ * access to priv->echo_skb, if necessary.
+ */
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
+{
+	struct sk_buff *skb;
+	u8 len;
+
+	skb = __can_get_echo_skb(dev, idx, &len);
+	if (!skb)
+		return 0;
+
+	skb_get(skb);
+	if (netif_rx(skb) == NET_RX_SUCCESS)
+		dev_consume_skb_any(skb);
+	else
+		dev_kfree_skb_any(skb);
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(can_get_echo_skb);
+
+/* Remove the skb from the stack and free it.
+ *
+ * The function is typically called when TX failed.
+ */
+void can_free_echo_skb(struct net_device *dev, unsigned int idx)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	BUG_ON(idx >= priv->echo_skb_max);
+
+	if (priv->echo_skb[idx]) {
+		dev_kfree_skb_any(priv->echo_skb[idx]);
+		priv->echo_skb[idx] = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(can_free_echo_skb);
+
+struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+			       sizeof(struct can_frame));
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_CAN);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+
+	*cf = skb_put_zero(skb, sizeof(struct can_frame));
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_skb);
+
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+				struct canfd_frame **cfd)
+{
+	struct sk_buff *skb;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_skb_priv) +
+			       sizeof(struct canfd_frame));
+	if (unlikely(!skb))
+		return NULL;
+
+	skb->protocol = htons(ETH_P_CANFD);
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+	skb_reset_mac_header(skb);
+	skb_reset_network_header(skb);
+	skb_reset_transport_header(skb);
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+
+	*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_canfd_skb);
+
+struct sk_buff *alloc_can_err_skb(struct net_device *dev, struct can_frame **cf)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_can_skb(dev, cf);
+	if (unlikely(!skb))
+		return NULL;
+
+	(*cf)->can_id = CAN_ERR_FLAG;
+	(*cf)->len = CAN_ERR_DLC;
+
+	return skb;
+}
+EXPORT_SYMBOL_GPL(alloc_can_err_skb);
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index d75fba1d030a..4a26e128af7f 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -84,69 +84,6 @@ struct can_priv {
 #endif
 };
 
-/* Check for outgoing skbs that have not been created by the CAN subsystem */
-static inline bool can_skb_headroom_valid(struct net_device *dev,
-					  struct sk_buff *skb)
-{
-	/* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
-	if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
-		return false;
-
-	/* af_packet does not apply CAN skb specific settings */
-	if (skb->ip_summed == CHECKSUM_NONE) {
-		/* init headroom */
-		can_skb_prv(skb)->ifindex = dev->ifindex;
-		can_skb_prv(skb)->skbcnt = 0;
-
-		skb->ip_summed = CHECKSUM_UNNECESSARY;
-
-		/* perform proper loopback on capable devices */
-		if (dev->flags & IFF_ECHO)
-			skb->pkt_type = PACKET_LOOPBACK;
-		else
-			skb->pkt_type = PACKET_HOST;
-
-		skb_reset_mac_header(skb);
-		skb_reset_network_header(skb);
-		skb_reset_transport_header(skb);
-	}
-
-	return true;
-}
-
-/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
-static inline bool can_dropped_invalid_skb(struct net_device *dev,
-					  struct sk_buff *skb)
-{
-	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
-
-	if (skb->protocol == htons(ETH_P_CAN)) {
-		if (unlikely(skb->len != CAN_MTU ||
-			     cfd->len > CAN_MAX_DLEN))
-			goto inval_skb;
-	} else if (skb->protocol == htons(ETH_P_CANFD)) {
-		if (unlikely(skb->len != CANFD_MTU ||
-			     cfd->len > CANFD_MAX_DLEN))
-			goto inval_skb;
-	} else
-		goto inval_skb;
-
-	if (!can_skb_headroom_valid(dev, skb))
-		goto inval_skb;
-
-	return false;
-
-inval_skb:
-	kfree_skb(skb);
-	dev->stats.tx_dropped++;
-	return true;
-}
-
-static inline bool can_is_canfd_skb(const struct sk_buff *skb)
-{
-	/* the CAN specific type of skb is identified by its data length */
-	return skb->len == CANFD_MTU;
-}
 
 /* helper to define static CAN controller features at device creation time */
 static inline void can_set_static_ctrlmode(struct net_device *dev,
@@ -187,23 +124,10 @@ void can_bus_off(struct net_device *dev);
 void can_change_state(struct net_device *dev, struct can_frame *cf,
 		      enum can_state tx_state, enum can_state rx_state);
 
-int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
-		     unsigned int idx);
-struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
-				   u8 *len_ptr);
-unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
-void can_free_echo_skb(struct net_device *dev, unsigned int idx);
-
 #ifdef CONFIG_OF
 void of_can_transceiver(struct net_device *dev);
 #else
 static inline void of_can_transceiver(struct net_device *dev) { }
 #endif
 
-struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
-struct sk_buff *alloc_canfd_skb(struct net_device *dev,
-				struct canfd_frame **cfd);
-struct sk_buff *alloc_can_err_skb(struct net_device *dev,
-				  struct can_frame **cf);
-
 #endif /* !_CAN_DEV_H */
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index fc61cf4eff1c..c90ebbd3008c 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -16,6 +16,19 @@
 #include <linux/can.h>
 #include <net/sock.h>
 
+void can_flush_echo_skb(struct net_device *dev);
+int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
+		     unsigned int idx);
+struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
+				   u8 *len_ptr);
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
+void can_free_echo_skb(struct net_device *dev, unsigned int idx);
+struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+				struct canfd_frame **cfd);
+struct sk_buff *alloc_can_err_skb(struct net_device *dev,
+				  struct can_frame **cf);
+
 /*
  * The struct can_skb_priv is used to transport additional information along
  * with the stored struct can(fd)_frame that can not be contained in existing
@@ -74,4 +87,68 @@ static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb)
 	return nskb;
 }
 
+/* Check for outgoing skbs that have not been created by the CAN subsystem */
+static inline bool can_skb_headroom_valid(struct net_device *dev,
+					  struct sk_buff *skb)
+{
+	/* af_packet creates a headroom of HH_DATA_MOD bytes which is fine */
+	if (WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct can_skb_priv)))
+		return false;
+
+	/* af_packet does not apply CAN skb specific settings */
+	if (skb->ip_summed == CHECKSUM_NONE) {
+		/* init headroom */
+		can_skb_prv(skb)->ifindex = dev->ifindex;
+		can_skb_prv(skb)->skbcnt = 0;
+
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+		/* perform proper loopback on capable devices */
+		if (dev->flags & IFF_ECHO)
+			skb->pkt_type = PACKET_LOOPBACK;
+		else
+			skb->pkt_type = PACKET_HOST;
+
+		skb_reset_mac_header(skb);
+		skb_reset_network_header(skb);
+		skb_reset_transport_header(skb);
+	}
+
+	return true;
+}
+
+/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
+static inline bool can_dropped_invalid_skb(struct net_device *dev,
+					  struct sk_buff *skb)
+{
+	const struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
+
+	if (skb->protocol == htons(ETH_P_CAN)) {
+		if (unlikely(skb->len != CAN_MTU ||
+			     cfd->len > CAN_MAX_DLEN))
+			goto inval_skb;
+	} else if (skb->protocol == htons(ETH_P_CANFD)) {
+		if (unlikely(skb->len != CANFD_MTU ||
+			     cfd->len > CANFD_MAX_DLEN))
+			goto inval_skb;
+	} else
+		goto inval_skb;
+
+	if (!can_skb_headroom_valid(dev, skb))
+		goto inval_skb;
+
+	return false;
+
+inval_skb:
+	kfree_skb(skb);
+	dev->stats.tx_dropped++;
+	return true;
+}
+
+static inline bool can_is_canfd_skb(const struct sk_buff *skb)
+{
+	/* the CAN specific type of skb is identified by its data length */
+	return skb->len == CANFD_MTU;
+}
+
 #endif /* !_CAN_SKB_H */
-- 
2.29.2

Re: [net-next v2 05/15] can: dev: move skb related into seperate file

[Vincent MAILHOL]

On Mon. 11 Jan 2021 at 19:45, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> This patch moves the skb related code of the CAN device infrastructure into a
> separate file.
>
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/net/can/dev/dev.c | 213 ------------------------------------
>  drivers/net/can/dev/skb.c | 220 ++++++++++++++++++++++++++++++++++++++
>  include/linux/can/dev.h   |  76 -------------
>  include/linux/can/skb.h   |  77 +++++++++++++
>  4 files changed, 297 insertions(+), 289 deletions(-)
>  create mode 100644 drivers/net/can/dev/skb.c
>
> [...]

Sorry but the changes on drivers/net/can/dev/Makefile are still
missing for the skb patch (however, it is now OK for the
netlink).

diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index 5c647951e06d..2c38bd532157 100644
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -5,5 +5,6 @@ can-dev-y                       += bittiming.o
 can-dev-y                      += dev.o
 can-dev-y                      += length.o
 can-dev-y                      += rx-offload.o
+can-dev-y                      += skb.o

 can-dev-$(CONFIG_CAN_LEDS)     += led.o


Yours sincerely,
Vincent

Re: [net-next v2 05/15] can: dev: move skb related into seperate file

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 1202 bytes --]

On 1/11/21 1:51 PM, Vincent MAILHOL wrote:
> On Mon. 11 Jan 2021 at 19:45, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>>
>> This patch moves the skb related code of the CAN device infrastructure into a
>> separate file.
>>
>> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
>> ---
>>  drivers/net/can/dev/dev.c | 213 ------------------------------------
>>  drivers/net/can/dev/skb.c | 220 ++++++++++++++++++++++++++++++++++++++
>>  include/linux/can/dev.h   |  76 -------------
>>  include/linux/can/skb.h   |  77 +++++++++++++
>>  4 files changed, 297 insertions(+), 289 deletions(-)
>>  create mode 100644 drivers/net/can/dev/skb.c
>>
>> [...]
> 
> Sorry but the changes on drivers/net/can/dev/Makefile are still
> missing for the skb patch (however, it is now OK for the
> netlink).

Hopefully fixed this time. Seems I have to compile the whole kernel to notice
the missing symbols :/

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
Vertretung West/Dortmund         | Phone: +49-231-2826-924     |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-5555 |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: [net-next v2 05/15] can: dev: move skb related into seperate file

[Vincent MAILHOL]

On Mon. 11 Jan 2021 at 23:20, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> On 1/11/21 1:51 PM, Vincent MAILHOL wrote:
> > On Mon. 11 Jan 2021 at 19:45, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> >>
> >> This patch moves the skb related code of the CAN device infrastructure into a
> >> separate file.
> >>
> >> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> >> ---
> >>  drivers/net/can/dev/dev.c | 213 ------------------------------------
> >>  drivers/net/can/dev/skb.c | 220 ++++++++++++++++++++++++++++++++++++++
> >>  include/linux/can/dev.h   |  76 -------------
> >>  include/linux/can/skb.h   |  77 +++++++++++++
> >>  4 files changed, 297 insertions(+), 289 deletions(-)
> >>  create mode 100644 drivers/net/can/dev/skb.c
> >>
> >> [...]
> >
> > Sorry but the changes on drivers/net/can/dev/Makefile are still
> > missing for the skb patch (however, it is now OK for the
> > netlink).
>
> Hopefully fixed this time. Seems I have to compile the whole kernel to notice
> the missing symbols :/

Yep, no more compilation issues!

I will do a few more tests but your v3 seems to be the good
one.

Will also adapt the changes to the ES58x driver and send my v10,
probably tomorrow (it's time to go to bed here).


Yours sincerely,
Vincent

[net-next v2 06/15] can: dev: move netlink related code into seperate file

[Marc Kleine-Budde]

This patch moves the netlink related code of the CAN device infrastructure into
a separate file.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/Makefile  |   1 +
 drivers/net/can/dev/dev.c     | 370 +--------------------------------
 drivers/net/can/dev/netlink.c | 379 ++++++++++++++++++++++++++++++++++
 include/linux/can/dev.h       |   6 +
 4 files changed, 389 insertions(+), 367 deletions(-)
 create mode 100644 drivers/net/can/dev/netlink.c

diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index 5c647951e06d..e647704fbf4d 100644
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_CAN_DEV)		+= can-dev.o
 can-dev-y			+= bittiming.o
 can-dev-y			+= dev.o
 can-dev-y			+= length.o
+can-dev-y			+= netlink.o
 can-dev-y			+= rx-offload.o
 
 can-dev-$(CONFIG_CAN_LEDS)	+= led.o
diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index fe71ff9ef8c9..f580f0ac6497 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -14,10 +14,8 @@
 #include <linux/can/can-ml.h>
 #include <linux/can/dev.h>
 #include <linux/can/skb.h>
-#include <linux/can/netlink.h>
 #include <linux/can/led.h>
 #include <linux/of.h>
-#include <net/rtnetlink.h>
 
 #define MOD_DESC "CAN device driver interface"
 
@@ -223,7 +221,7 @@ void can_bus_off(struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(can_bus_off);
 
-static void can_setup(struct net_device *dev)
+void can_setup(struct net_device *dev)
 {
 	dev->type = ARPHRD_CAN;
 	dev->mtu = CAN_MTU;
@@ -399,368 +397,6 @@ void close_candev(struct net_device *dev)
 }
 EXPORT_SYMBOL_GPL(close_candev);
 
-/* CAN netlink interface */
-static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
-	[IFLA_CAN_STATE]	= { .type = NLA_U32 },
-	[IFLA_CAN_CTRLMODE]	= { .len = sizeof(struct can_ctrlmode) },
-	[IFLA_CAN_RESTART_MS]	= { .type = NLA_U32 },
-	[IFLA_CAN_RESTART]	= { .type = NLA_U32 },
-	[IFLA_CAN_BITTIMING]	= { .len = sizeof(struct can_bittiming) },
-	[IFLA_CAN_BITTIMING_CONST]
-				= { .len = sizeof(struct can_bittiming_const) },
-	[IFLA_CAN_CLOCK]	= { .len = sizeof(struct can_clock) },
-	[IFLA_CAN_BERR_COUNTER]	= { .len = sizeof(struct can_berr_counter) },
-	[IFLA_CAN_DATA_BITTIMING]
-				= { .len = sizeof(struct can_bittiming) },
-	[IFLA_CAN_DATA_BITTIMING_CONST]
-				= { .len = sizeof(struct can_bittiming_const) },
-	[IFLA_CAN_TERMINATION]	= { .type = NLA_U16 },
-};
-
-static int can_validate(struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
-{
-	bool is_can_fd = false;
-
-	/* Make sure that valid CAN FD configurations always consist of
-	 * - nominal/arbitration bittiming
-	 * - data bittiming
-	 * - control mode with CAN_CTRLMODE_FD set
-	 */
-
-	if (!data)
-		return 0;
-
-	if (data[IFLA_CAN_CTRLMODE]) {
-		struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
-
-		is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
-	}
-
-	if (is_can_fd) {
-		if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
-			return -EOPNOTSUPP;
-	}
-
-	if (data[IFLA_CAN_DATA_BITTIMING]) {
-		if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
-			return -EOPNOTSUPP;
-	}
-
-	return 0;
-}
-
-static int can_changelink(struct net_device *dev, struct nlattr *tb[],
-			  struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	int err;
-
-	/* We need synchronization with dev->stop() */
-	ASSERT_RTNL();
-
-	if (data[IFLA_CAN_BITTIMING]) {
-		struct can_bittiming bt;
-
-		/* Do not allow changing bittiming while running */
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-
-		/* Calculate bittiming parameters based on
-		 * bittiming_const if set, otherwise pass bitrate
-		 * directly via do_set_bitrate(). Bail out if neither
-		 * is given.
-		 */
-		if (!priv->bittiming_const && !priv->do_set_bittiming)
-			return -EOPNOTSUPP;
-
-		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
-		err = can_get_bittiming(dev, &bt,
-					priv->bittiming_const,
-					priv->bitrate_const,
-					priv->bitrate_const_cnt);
-		if (err)
-			return err;
-
-		if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
-			netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
-				   priv->bitrate_max);
-			return -EINVAL;
-		}
-
-		memcpy(&priv->bittiming, &bt, sizeof(bt));
-
-		if (priv->do_set_bittiming) {
-			/* Finally, set the bit-timing registers */
-			err = priv->do_set_bittiming(dev);
-			if (err)
-				return err;
-		}
-	}
-
-	if (data[IFLA_CAN_CTRLMODE]) {
-		struct can_ctrlmode *cm;
-		u32 ctrlstatic;
-		u32 maskedflags;
-
-		/* Do not allow changing controller mode while running */
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
-		ctrlstatic = priv->ctrlmode_static;
-		maskedflags = cm->flags & cm->mask;
-
-		/* check whether provided bits are allowed to be passed */
-		if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
-			return -EOPNOTSUPP;
-
-		/* do not check for static fd-non-iso if 'fd' is disabled */
-		if (!(maskedflags & CAN_CTRLMODE_FD))
-			ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
-
-		/* make sure static options are provided by configuration */
-		if ((maskedflags & ctrlstatic) != ctrlstatic)
-			return -EOPNOTSUPP;
-
-		/* clear bits to be modified and copy the flag values */
-		priv->ctrlmode &= ~cm->mask;
-		priv->ctrlmode |= maskedflags;
-
-		/* CAN_CTRLMODE_FD can only be set when driver supports FD */
-		if (priv->ctrlmode & CAN_CTRLMODE_FD)
-			dev->mtu = CANFD_MTU;
-		else
-			dev->mtu = CAN_MTU;
-	}
-
-	if (data[IFLA_CAN_RESTART_MS]) {
-		/* Do not allow changing restart delay while running */
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-		priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
-	}
-
-	if (data[IFLA_CAN_RESTART]) {
-		/* Do not allow a restart while not running */
-		if (!(dev->flags & IFF_UP))
-			return -EINVAL;
-		err = can_restart_now(dev);
-		if (err)
-			return err;
-	}
-
-	if (data[IFLA_CAN_DATA_BITTIMING]) {
-		struct can_bittiming dbt;
-
-		/* Do not allow changing bittiming while running */
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-
-		/* Calculate bittiming parameters based on
-		 * data_bittiming_const if set, otherwise pass bitrate
-		 * directly via do_set_bitrate(). Bail out if neither
-		 * is given.
-		 */
-		if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
-			return -EOPNOTSUPP;
-
-		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
-		       sizeof(dbt));
-		err = can_get_bittiming(dev, &dbt,
-					priv->data_bittiming_const,
-					priv->data_bitrate_const,
-					priv->data_bitrate_const_cnt);
-		if (err)
-			return err;
-
-		if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
-			netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
-				   priv->bitrate_max);
-			return -EINVAL;
-		}
-
-		memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
-
-		if (priv->do_set_data_bittiming) {
-			/* Finally, set the bit-timing registers */
-			err = priv->do_set_data_bittiming(dev);
-			if (err)
-				return err;
-		}
-	}
-
-	if (data[IFLA_CAN_TERMINATION]) {
-		const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
-		const unsigned int num_term = priv->termination_const_cnt;
-		unsigned int i;
-
-		if (!priv->do_set_termination)
-			return -EOPNOTSUPP;
-
-		/* check whether given value is supported by the interface */
-		for (i = 0; i < num_term; i++) {
-			if (termval == priv->termination_const[i])
-				break;
-		}
-		if (i >= num_term)
-			return -EINVAL;
-
-		/* Finally, set the termination value */
-		err = priv->do_set_termination(dev, termval);
-		if (err)
-			return err;
-
-		priv->termination = termval;
-	}
-
-	return 0;
-}
-
-static size_t can_get_size(const struct net_device *dev)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	size_t size = 0;
-
-	if (priv->bittiming.bitrate)				/* IFLA_CAN_BITTIMING */
-		size += nla_total_size(sizeof(struct can_bittiming));
-	if (priv->bittiming_const)				/* IFLA_CAN_BITTIMING_CONST */
-		size += nla_total_size(sizeof(struct can_bittiming_const));
-	size += nla_total_size(sizeof(struct can_clock));	/* IFLA_CAN_CLOCK */
-	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_STATE */
-	size += nla_total_size(sizeof(struct can_ctrlmode));	/* IFLA_CAN_CTRLMODE */
-	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_RESTART_MS */
-	if (priv->do_get_berr_counter)				/* IFLA_CAN_BERR_COUNTER */
-		size += nla_total_size(sizeof(struct can_berr_counter));
-	if (priv->data_bittiming.bitrate)			/* IFLA_CAN_DATA_BITTIMING */
-		size += nla_total_size(sizeof(struct can_bittiming));
-	if (priv->data_bittiming_const)				/* IFLA_CAN_DATA_BITTIMING_CONST */
-		size += nla_total_size(sizeof(struct can_bittiming_const));
-	if (priv->termination_const) {
-		size += nla_total_size(sizeof(priv->termination));		/* IFLA_CAN_TERMINATION */
-		size += nla_total_size(sizeof(*priv->termination_const) *	/* IFLA_CAN_TERMINATION_CONST */
-				       priv->termination_const_cnt);
-	}
-	if (priv->bitrate_const)				/* IFLA_CAN_BITRATE_CONST */
-		size += nla_total_size(sizeof(*priv->bitrate_const) *
-				       priv->bitrate_const_cnt);
-	if (priv->data_bitrate_const)				/* IFLA_CAN_DATA_BITRATE_CONST */
-		size += nla_total_size(sizeof(*priv->data_bitrate_const) *
-				       priv->data_bitrate_const_cnt);
-	size += sizeof(priv->bitrate_max);			/* IFLA_CAN_BITRATE_MAX */
-
-	return size;
-}
-
-static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
-{
-	struct can_priv *priv = netdev_priv(dev);
-	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
-	struct can_berr_counter bec;
-	enum can_state state = priv->state;
-
-	if (priv->do_get_state)
-		priv->do_get_state(dev, &state);
-
-	if ((priv->bittiming.bitrate &&
-	     nla_put(skb, IFLA_CAN_BITTIMING,
-		     sizeof(priv->bittiming), &priv->bittiming)) ||
-
-	    (priv->bittiming_const &&
-	     nla_put(skb, IFLA_CAN_BITTIMING_CONST,
-		     sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
-
-	    nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
-	    nla_put_u32(skb, IFLA_CAN_STATE, state) ||
-	    nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
-	    nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
-
-	    (priv->do_get_berr_counter &&
-	     !priv->do_get_berr_counter(dev, &bec) &&
-	     nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
-
-	    (priv->data_bittiming.bitrate &&
-	     nla_put(skb, IFLA_CAN_DATA_BITTIMING,
-		     sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
-
-	    (priv->data_bittiming_const &&
-	     nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
-		     sizeof(*priv->data_bittiming_const),
-		     priv->data_bittiming_const)) ||
-
-	    (priv->termination_const &&
-	     (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
-	      nla_put(skb, IFLA_CAN_TERMINATION_CONST,
-		      sizeof(*priv->termination_const) *
-		      priv->termination_const_cnt,
-		      priv->termination_const))) ||
-
-	    (priv->bitrate_const &&
-	     nla_put(skb, IFLA_CAN_BITRATE_CONST,
-		     sizeof(*priv->bitrate_const) *
-		     priv->bitrate_const_cnt,
-		     priv->bitrate_const)) ||
-
-	    (priv->data_bitrate_const &&
-	     nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
-		     sizeof(*priv->data_bitrate_const) *
-		     priv->data_bitrate_const_cnt,
-		     priv->data_bitrate_const)) ||
-
-	    (nla_put(skb, IFLA_CAN_BITRATE_MAX,
-		     sizeof(priv->bitrate_max),
-		     &priv->bitrate_max))
-	    )
-
-		return -EMSGSIZE;
-
-	return 0;
-}
-
-static size_t can_get_xstats_size(const struct net_device *dev)
-{
-	return sizeof(struct can_device_stats);
-}
-
-static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
-{
-	struct can_priv *priv = netdev_priv(dev);
-
-	if (nla_put(skb, IFLA_INFO_XSTATS,
-		    sizeof(priv->can_stats), &priv->can_stats))
-		goto nla_put_failure;
-	return 0;
-
-nla_put_failure:
-	return -EMSGSIZE;
-}
-
-static int can_newlink(struct net *src_net, struct net_device *dev,
-		       struct nlattr *tb[], struct nlattr *data[],
-		       struct netlink_ext_ack *extack)
-{
-	return -EOPNOTSUPP;
-}
-
-static void can_dellink(struct net_device *dev, struct list_head *head)
-{
-}
-
-static struct rtnl_link_ops can_link_ops __read_mostly = {
-	.kind		= "can",
-	.maxtype	= IFLA_CAN_MAX,
-	.policy		= can_policy,
-	.setup		= can_setup,
-	.validate	= can_validate,
-	.newlink	= can_newlink,
-	.changelink	= can_changelink,
-	.dellink	= can_dellink,
-	.get_size	= can_get_size,
-	.fill_info	= can_fill_info,
-	.get_xstats_size = can_get_xstats_size,
-	.fill_xstats	= can_fill_xstats,
-};
-
 /* Register the CAN network device */
 int register_candev(struct net_device *dev)
 {
@@ -812,7 +448,7 @@ static __init int can_dev_init(void)
 
 	can_led_notifier_init();
 
-	err = rtnl_link_register(&can_link_ops);
+	err = can_netlink_register();
 	if (!err)
 		pr_info(MOD_DESC "\n");
 
@@ -822,7 +458,7 @@ module_init(can_dev_init);
 
 static __exit void can_dev_exit(void)
 {
-	rtnl_link_unregister(&can_link_ops);
+	can_netlink_unregister();
 
 	can_led_notifier_exit();
 }
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
new file mode 100644
index 000000000000..3ae884cdf677
--- /dev/null
+++ b/drivers/net/can/dev/netlink.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2005 Marc Kleine-Budde, Pengutronix
+ * Copyright (C) 2006 Andrey Volkov, Varma Electronics
+ * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com>
+ */
+
+#include <linux/can/dev.h>
+#include <net/rtnetlink.h>
+
+static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
+	[IFLA_CAN_STATE]	= { .type = NLA_U32 },
+	[IFLA_CAN_CTRLMODE]	= { .len = sizeof(struct can_ctrlmode) },
+	[IFLA_CAN_RESTART_MS]	= { .type = NLA_U32 },
+	[IFLA_CAN_RESTART]	= { .type = NLA_U32 },
+	[IFLA_CAN_BITTIMING]	= { .len = sizeof(struct can_bittiming) },
+	[IFLA_CAN_BITTIMING_CONST]
+				= { .len = sizeof(struct can_bittiming_const) },
+	[IFLA_CAN_CLOCK]	= { .len = sizeof(struct can_clock) },
+	[IFLA_CAN_BERR_COUNTER]	= { .len = sizeof(struct can_berr_counter) },
+	[IFLA_CAN_DATA_BITTIMING]
+				= { .len = sizeof(struct can_bittiming) },
+	[IFLA_CAN_DATA_BITTIMING_CONST]
+				= { .len = sizeof(struct can_bittiming_const) },
+	[IFLA_CAN_TERMINATION]	= { .type = NLA_U16 },
+};
+
+static int can_validate(struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	bool is_can_fd = false;
+
+	/* Make sure that valid CAN FD configurations always consist of
+	 * - nominal/arbitration bittiming
+	 * - data bittiming
+	 * - control mode with CAN_CTRLMODE_FD set
+	 */
+
+	if (!data)
+		return 0;
+
+	if (data[IFLA_CAN_CTRLMODE]) {
+		struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+
+		is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
+	}
+
+	if (is_can_fd) {
+		if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
+			return -EOPNOTSUPP;
+	}
+
+	if (data[IFLA_CAN_DATA_BITTIMING]) {
+		if (!is_can_fd || !data[IFLA_CAN_BITTIMING])
+			return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int can_changelink(struct net_device *dev, struct nlattr *tb[],
+			  struct nlattr *data[],
+			  struct netlink_ext_ack *extack)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	int err;
+
+	/* We need synchronization with dev->stop() */
+	ASSERT_RTNL();
+
+	if (data[IFLA_CAN_BITTIMING]) {
+		struct can_bittiming bt;
+
+		/* Do not allow changing bittiming while running */
+		if (dev->flags & IFF_UP)
+			return -EBUSY;
+
+		/* Calculate bittiming parameters based on
+		 * bittiming_const if set, otherwise pass bitrate
+		 * directly via do_set_bitrate(). Bail out if neither
+		 * is given.
+		 */
+		if (!priv->bittiming_const && !priv->do_set_bittiming)
+			return -EOPNOTSUPP;
+
+		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
+		err = can_get_bittiming(dev, &bt,
+					priv->bittiming_const,
+					priv->bitrate_const,
+					priv->bitrate_const_cnt);
+		if (err)
+			return err;
+
+		if (priv->bitrate_max && bt.bitrate > priv->bitrate_max) {
+			netdev_err(dev, "arbitration bitrate surpasses transceiver capabilities of %d bps\n",
+				   priv->bitrate_max);
+			return -EINVAL;
+		}
+
+		memcpy(&priv->bittiming, &bt, sizeof(bt));
+
+		if (priv->do_set_bittiming) {
+			/* Finally, set the bit-timing registers */
+			err = priv->do_set_bittiming(dev);
+			if (err)
+				return err;
+		}
+	}
+
+	if (data[IFLA_CAN_CTRLMODE]) {
+		struct can_ctrlmode *cm;
+		u32 ctrlstatic;
+		u32 maskedflags;
+
+		/* Do not allow changing controller mode while running */
+		if (dev->flags & IFF_UP)
+			return -EBUSY;
+		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+		ctrlstatic = priv->ctrlmode_static;
+		maskedflags = cm->flags & cm->mask;
+
+		/* check whether provided bits are allowed to be passed */
+		if (cm->mask & ~(priv->ctrlmode_supported | ctrlstatic))
+			return -EOPNOTSUPP;
+
+		/* do not check for static fd-non-iso if 'fd' is disabled */
+		if (!(maskedflags & CAN_CTRLMODE_FD))
+			ctrlstatic &= ~CAN_CTRLMODE_FD_NON_ISO;
+
+		/* make sure static options are provided by configuration */
+		if ((maskedflags & ctrlstatic) != ctrlstatic)
+			return -EOPNOTSUPP;
+
+		/* clear bits to be modified and copy the flag values */
+		priv->ctrlmode &= ~cm->mask;
+		priv->ctrlmode |= maskedflags;
+
+		/* CAN_CTRLMODE_FD can only be set when driver supports FD */
+		if (priv->ctrlmode & CAN_CTRLMODE_FD)
+			dev->mtu = CANFD_MTU;
+		else
+			dev->mtu = CAN_MTU;
+	}
+
+	if (data[IFLA_CAN_RESTART_MS]) {
+		/* Do not allow changing restart delay while running */
+		if (dev->flags & IFF_UP)
+			return -EBUSY;
+		priv->restart_ms = nla_get_u32(data[IFLA_CAN_RESTART_MS]);
+	}
+
+	if (data[IFLA_CAN_RESTART]) {
+		/* Do not allow a restart while not running */
+		if (!(dev->flags & IFF_UP))
+			return -EINVAL;
+		err = can_restart_now(dev);
+		if (err)
+			return err;
+	}
+
+	if (data[IFLA_CAN_DATA_BITTIMING]) {
+		struct can_bittiming dbt;
+
+		/* Do not allow changing bittiming while running */
+		if (dev->flags & IFF_UP)
+			return -EBUSY;
+
+		/* Calculate bittiming parameters based on
+		 * data_bittiming_const if set, otherwise pass bitrate
+		 * directly via do_set_bitrate(). Bail out if neither
+		 * is given.
+		 */
+		if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)
+			return -EOPNOTSUPP;
+
+		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
+		       sizeof(dbt));
+		err = can_get_bittiming(dev, &dbt,
+					priv->data_bittiming_const,
+					priv->data_bitrate_const,
+					priv->data_bitrate_const_cnt);
+		if (err)
+			return err;
+
+		if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
+			netdev_err(dev, "canfd data bitrate surpasses transceiver capabilities of %d bps\n",
+				   priv->bitrate_max);
+			return -EINVAL;
+		}
+
+		memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));
+
+		if (priv->do_set_data_bittiming) {
+			/* Finally, set the bit-timing registers */
+			err = priv->do_set_data_bittiming(dev);
+			if (err)
+				return err;
+		}
+	}
+
+	if (data[IFLA_CAN_TERMINATION]) {
+		const u16 termval = nla_get_u16(data[IFLA_CAN_TERMINATION]);
+		const unsigned int num_term = priv->termination_const_cnt;
+		unsigned int i;
+
+		if (!priv->do_set_termination)
+			return -EOPNOTSUPP;
+
+		/* check whether given value is supported by the interface */
+		for (i = 0; i < num_term; i++) {
+			if (termval == priv->termination_const[i])
+				break;
+		}
+		if (i >= num_term)
+			return -EINVAL;
+
+		/* Finally, set the termination value */
+		err = priv->do_set_termination(dev, termval);
+		if (err)
+			return err;
+
+		priv->termination = termval;
+	}
+
+	return 0;
+}
+
+static size_t can_get_size(const struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	size_t size = 0;
+
+	if (priv->bittiming.bitrate)				/* IFLA_CAN_BITTIMING */
+		size += nla_total_size(sizeof(struct can_bittiming));
+	if (priv->bittiming_const)				/* IFLA_CAN_BITTIMING_CONST */
+		size += nla_total_size(sizeof(struct can_bittiming_const));
+	size += nla_total_size(sizeof(struct can_clock));	/* IFLA_CAN_CLOCK */
+	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_STATE */
+	size += nla_total_size(sizeof(struct can_ctrlmode));	/* IFLA_CAN_CTRLMODE */
+	size += nla_total_size(sizeof(u32));			/* IFLA_CAN_RESTART_MS */
+	if (priv->do_get_berr_counter)				/* IFLA_CAN_BERR_COUNTER */
+		size += nla_total_size(sizeof(struct can_berr_counter));
+	if (priv->data_bittiming.bitrate)			/* IFLA_CAN_DATA_BITTIMING */
+		size += nla_total_size(sizeof(struct can_bittiming));
+	if (priv->data_bittiming_const)				/* IFLA_CAN_DATA_BITTIMING_CONST */
+		size += nla_total_size(sizeof(struct can_bittiming_const));
+	if (priv->termination_const) {
+		size += nla_total_size(sizeof(priv->termination));		/* IFLA_CAN_TERMINATION */
+		size += nla_total_size(sizeof(*priv->termination_const) *	/* IFLA_CAN_TERMINATION_CONST */
+				       priv->termination_const_cnt);
+	}
+	if (priv->bitrate_const)				/* IFLA_CAN_BITRATE_CONST */
+		size += nla_total_size(sizeof(*priv->bitrate_const) *
+				       priv->bitrate_const_cnt);
+	if (priv->data_bitrate_const)				/* IFLA_CAN_DATA_BITRATE_CONST */
+		size += nla_total_size(sizeof(*priv->data_bitrate_const) *
+				       priv->data_bitrate_const_cnt);
+	size += sizeof(priv->bitrate_max);			/* IFLA_CAN_BITRATE_MAX */
+
+	return size;
+}
+
+static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct can_ctrlmode cm = {.flags = priv->ctrlmode};
+	struct can_berr_counter bec;
+	enum can_state state = priv->state;
+
+	if (priv->do_get_state)
+		priv->do_get_state(dev, &state);
+
+	if ((priv->bittiming.bitrate &&
+	     nla_put(skb, IFLA_CAN_BITTIMING,
+		     sizeof(priv->bittiming), &priv->bittiming)) ||
+
+	    (priv->bittiming_const &&
+	     nla_put(skb, IFLA_CAN_BITTIMING_CONST,
+		     sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
+
+	    nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
+	    nla_put_u32(skb, IFLA_CAN_STATE, state) ||
+	    nla_put(skb, IFLA_CAN_CTRLMODE, sizeof(cm), &cm) ||
+	    nla_put_u32(skb, IFLA_CAN_RESTART_MS, priv->restart_ms) ||
+
+	    (priv->do_get_berr_counter &&
+	     !priv->do_get_berr_counter(dev, &bec) &&
+	     nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
+
+	    (priv->data_bittiming.bitrate &&
+	     nla_put(skb, IFLA_CAN_DATA_BITTIMING,
+		     sizeof(priv->data_bittiming), &priv->data_bittiming)) ||
+
+	    (priv->data_bittiming_const &&
+	     nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
+		     sizeof(*priv->data_bittiming_const),
+		     priv->data_bittiming_const)) ||
+
+	    (priv->termination_const &&
+	     (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
+	      nla_put(skb, IFLA_CAN_TERMINATION_CONST,
+		      sizeof(*priv->termination_const) *
+		      priv->termination_const_cnt,
+		      priv->termination_const))) ||
+
+	    (priv->bitrate_const &&
+	     nla_put(skb, IFLA_CAN_BITRATE_CONST,
+		     sizeof(*priv->bitrate_const) *
+		     priv->bitrate_const_cnt,
+		     priv->bitrate_const)) ||
+
+	    (priv->data_bitrate_const &&
+	     nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
+		     sizeof(*priv->data_bitrate_const) *
+		     priv->data_bitrate_const_cnt,
+		     priv->data_bitrate_const)) ||
+
+	    (nla_put(skb, IFLA_CAN_BITRATE_MAX,
+		     sizeof(priv->bitrate_max),
+		     &priv->bitrate_max))
+	    )
+
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static size_t can_get_xstats_size(const struct net_device *dev)
+{
+	return sizeof(struct can_device_stats);
+}
+
+static int can_fill_xstats(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (nla_put(skb, IFLA_INFO_XSTATS,
+		    sizeof(priv->can_stats), &priv->can_stats))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static int can_newlink(struct net *src_net, struct net_device *dev,
+		       struct nlattr *tb[], struct nlattr *data[],
+		       struct netlink_ext_ack *extack)
+{
+	return -EOPNOTSUPP;
+}
+
+static void can_dellink(struct net_device *dev, struct list_head *head)
+{
+}
+
+struct rtnl_link_ops can_link_ops __read_mostly = {
+	.kind		= "can",
+	.maxtype	= IFLA_CAN_MAX,
+	.policy		= can_policy,
+	.setup		= can_setup,
+	.validate	= can_validate,
+	.newlink	= can_newlink,
+	.changelink	= can_changelink,
+	.dellink	= can_dellink,
+	.get_size	= can_get_size,
+	.fill_info	= can_fill_info,
+	.get_xstats_size = can_get_xstats_size,
+	.fill_xstats	= can_fill_xstats,
+};
+
+int can_netlink_register(void)
+{
+	return rtnl_link_register(&can_link_ops);
+}
+
+void can_netlink_unregister(void)
+{
+	rtnl_link_unregister(&can_link_ops);
+}
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 4a26e128af7f..7faf6a37d5b2 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -100,6 +100,8 @@ static inline void can_set_static_ctrlmode(struct net_device *dev,
 		dev->mtu = CANFD_MTU;
 }
 
+void can_setup(struct net_device *dev);
+
 struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max,
 				    unsigned int txqs, unsigned int rxqs);
 #define alloc_candev(sizeof_priv, echo_skb_max) \
@@ -130,4 +132,8 @@ void of_can_transceiver(struct net_device *dev);
 static inline void of_can_transceiver(struct net_device *dev) { }
 #endif
 
+extern struct rtnl_link_ops can_link_ops;
+int can_netlink_register(void);
+void can_netlink_unregister(void);
+
 #endif /* !_CAN_DEV_H */
-- 
2.29.2

[net-next v2 07/15] can: length: convert to kernel coding style

[Marc Kleine-Budde]

This patch converts the file into the kernel coding style.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/length.c | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c
index 6fe18aa23ec9..5e7d481717ea 100644
--- a/drivers/net/can/dev/length.c
+++ b/drivers/net/can/dev/length.c
@@ -6,8 +6,10 @@
 
 /* CAN DLC to real data length conversion helpers */
 
-static const u8 dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
-			     8, 12, 16, 20, 24, 32, 48, 64};
+static const u8 dlc2len[] = {
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 12, 16, 20, 24, 32, 48, 64
+};
 
 /* get data length from raw data length code (DLC) */
 u8 can_fd_dlc2len(u8 dlc)
@@ -16,16 +18,18 @@ u8 can_fd_dlc2len(u8 dlc)
 }
 EXPORT_SYMBOL_GPL(can_fd_dlc2len);
 
-static const u8 len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
-			     9, 9, 9, 9,			/* 9 - 12 */
-			     10, 10, 10, 10,			/* 13 - 16 */
-			     11, 11, 11, 11,			/* 17 - 20 */
-			     12, 12, 12, 12,			/* 21 - 24 */
-			     13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
-			     14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
-			     14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
-			     15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
-			     15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */
+static const u8 len2dlc[] = {
+	0, 1, 2, 3, 4, 5, 6, 7, 8,	/* 0 - 8 */
+	9, 9, 9, 9,			/* 9 - 12 */
+	10, 10, 10, 10,			/* 13 - 16 */
+	11, 11, 11, 11,			/* 17 - 20 */
+	12, 12, 12, 12,			/* 21 - 24 */
+	13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
+	14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
+	14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
+	15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
+	15, 15, 15, 15, 15, 15, 15, 15	/* 57 - 64 */
+};
 
 /* map the sanitized data length to an appropriate data length code */
 u8 can_fd_len2dlc(u8 len)
-- 
2.29.2

[net-next v2 08/15] can: length: can_fd_len2dlc(): simplify length calculcation

[Marc Kleine-Budde]

If the length paramter in len2dlc() exceeds the size of the len2dlc array, we
return 0xF. This is equal to the last 16 members of the array.

This patch removes these members from the array, uses ARRAY_SIZE() for the
length check, and returns CANFD_MAX_DLC (which is 0xf).

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/length.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c
index 5e7d481717ea..d695a3bee1ed 100644
--- a/drivers/net/can/dev/length.c
+++ b/drivers/net/can/dev/length.c
@@ -27,15 +27,13 @@ static const u8 len2dlc[] = {
 	13, 13, 13, 13, 13, 13, 13, 13,	/* 25 - 32 */
 	14, 14, 14, 14, 14, 14, 14, 14,	/* 33 - 40 */
 	14, 14, 14, 14, 14, 14, 14, 14,	/* 41 - 48 */
-	15, 15, 15, 15, 15, 15, 15, 15,	/* 49 - 56 */
-	15, 15, 15, 15, 15, 15, 15, 15	/* 57 - 64 */
 };
 
 /* map the sanitized data length to an appropriate data length code */
 u8 can_fd_len2dlc(u8 len)
 {
-	if (unlikely(len > 64))
-		return 0xF;
+	if (len > ARRAY_SIZE(len2dlc))
+		return CANFD_MAX_DLC;
 
 	return len2dlc[len];
 }
-- 
2.29.2

[net-next v2 09/15] can: length: canfd_sanitize_len(): add function to sanitize CAN-FD data length

[Marc Kleine-Budde]

The data field in CAN-FD frames have specifig frame length (0, 1, 2, 3, 4, 5,
6, 7, 8, 12, 16, 20, 24, 32, 48, 64). This function "rounds" up a given length
to the next valid CAN-FD frame length.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 include/linux/can/length.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/can/length.h b/include/linux/can/length.h
index 156b9d17969a..b2313b2a0b02 100644
--- a/include/linux/can/length.h
+++ b/include/linux/can/length.h
@@ -45,4 +45,10 @@ u8 can_fd_dlc2len(u8 dlc);
 /* map the sanitized data length to an appropriate data length code */
 u8 can_fd_len2dlc(u8 len);
 
+/* map the data length to an appropriate data link layer length */
+static inline u8 canfd_sanitize_len(u8 len)
+{
+	return can_fd_dlc2len(can_fd_len2dlc(len));
+}
+
 #endif /* !_CAN_LENGTH_H */
-- 
2.29.2

[net-next v2 10/15] can: length: can_skb_get_frame_len(): introduce function to get data length of frame in data link layer

[Marc Kleine-Budde]

From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

This patch adds the function can_skb_get_frame_len() which returns the length
of a CAN frame on the data link layer, including Start-of-frame, Identifier,
various other bits, the actual data, the CRC, the End-of-frame, the Inter frame
spacing.

Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Not-Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Co-developed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Not-Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Co-developed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/length.c |  50 +++++++++++++++
 include/linux/can/length.h   | 120 +++++++++++++++++++++++++++++++++++
 2 files changed, 170 insertions(+)

diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c
index d695a3bee1ed..20cd153a45a5 100644
--- a/drivers/net/can/dev/length.c
+++ b/drivers/net/can/dev/length.c
@@ -38,3 +38,53 @@ u8 can_fd_len2dlc(u8 len)
 	return len2dlc[len];
 }
 EXPORT_SYMBOL_GPL(can_fd_len2dlc);
+
+/**
+ * can_skb_get_frame_len() - Calculate the CAN Frame length in bytes
+ * 	of a given skb.
+ * @skb: socket buffer of a CAN message.
+ *
+ * Do a rough calculation: bit stuffing is ignored and length in bits
+ * is rounded up to a length in bytes.
+ *
+ * Rationale: this function is to be used for the BQL functions
+ * (netdev_sent_queue() and netdev_completed_queue()) which expect a
+ * value in bytes. Just using skb->len is insufficient because it will
+ * return the constant value of CAN(FD)_MTU. Doing the bit stuffing
+ * calculation would be too expensive in term of computing resources
+ * for no noticeable gain.
+ *
+ * Remarks: The payload of CAN FD frames with BRS flag are sent at a
+ * different bitrate. Currently, the can-utils canbusload tool does
+ * not support CAN-FD yet and so we could not run any benchmark to
+ * measure the impact. There might be possible improvement here.
+ *
+ * Return: length in bytes.
+ */
+unsigned int can_skb_get_frame_len(const struct sk_buff *skb)
+{
+	const struct canfd_frame *cf = (const struct canfd_frame *)skb->data;
+	u8 len;
+
+	if (can_is_canfd_skb(skb))
+		len = canfd_sanitize_len(cf->len);
+	else if (cf->can_id & CAN_RTR_FLAG)
+		len = 0;
+	else
+		len = cf->len;
+
+	if (can_is_canfd_skb(skb)) {
+		if (cf->can_id & CAN_EFF_FLAG)
+			len += CANFD_FRAME_OVERHEAD_EFF;
+		else
+			len += CANFD_FRAME_OVERHEAD_SFF;
+	} else {
+		if (cf->can_id & CAN_EFF_FLAG)
+			len += CAN_FRAME_OVERHEAD_EFF;
+		else
+			len += CAN_FRAME_OVERHEAD_SFF;
+	}
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(can_skb_get_frame_len);
diff --git a/include/linux/can/length.h b/include/linux/can/length.h
index b2313b2a0b02..6995092b774e 100644
--- a/include/linux/can/length.h
+++ b/include/linux/can/length.h
@@ -1,10 +1,127 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2020 Oliver Hartkopp <socketcan@hartkopp.net>
+ * Copyright (C) 2020 Marc Kleine-Budde <kernel@pengutronix.de>
  */
 
 #ifndef _CAN_LENGTH_H
 #define _CAN_LENGTH_H
 
+/*
+ * Size of a Classical CAN Standard Frame
+ *
+ * Name of Field			Bits
+ * ---------------------------------------------------------
+ * Start-of-frame			1
+ * Identifier				11
+ * Remote transmission request (RTR)	1
+ * Identifier extension bit (IDE)	1
+ * Reserved bit (r0)			1
+ * Data length code (DLC)		4
+ * Data field				0...64
+ * CRC					15
+ * CRC delimiter			1
+ * ACK slot				1
+ * ACK delimiter			1
+ * End-of-frame (EOF)			7
+ * Inter frame spacing			3
+ *
+ * rounded up and ignoring bitstuffing
+ */
+#define CAN_FRAME_OVERHEAD_SFF DIV_ROUND_UP(47, 8)
+
+/*
+ * Size of a Classical CAN Extended Frame
+ *
+ * Name of Field			Bits
+ * ---------------------------------------------------------
+ * Start-of-frame			1
+ * Identifier A				11
+ * Substitute remote request (SRR)	1
+ * Identifier extension bit (IDE)	1
+ * Identifier B				18
+ * Remote transmission request (RTR)	1
+ * Reserved bits (r1, r0)		2
+ * Data length code (DLC)		4
+ * Data field				0...64
+ * CRC					15
+ * CRC delimiter			1
+ * ACK slot				1
+ * ACK delimiter			1
+ * End-of-frame (EOF)			7
+ * Inter frame spacing			3
+ *
+ * rounded up and ignoring bitstuffing
+ */
+#define CAN_FRAME_OVERHEAD_EFF DIV_ROUND_UP(67, 8)
+
+/*
+ * Size of a CAN-FD Standard Frame
+ *
+ * Name of Field			Bits
+ * ---------------------------------------------------------
+ * Start-of-frame			1
+ * Identifier				11
+ * Reserved bit (r1)			1
+ * Identifier extension bit (IDE)	1
+ * Flexible data rate format (FDF)	1
+ * Reserved bit (r0)			1
+ * Bit Rate Switch (BRS)		1
+ * Error Status Indicator (ESI)		1
+ * Data length code (DLC)		4
+ * Data field				0...512
+ * Stuff Bit Count (SBC)		0...16: 4 20...64:5
+ * CRC					0...16: 17 20...64:21
+ * CRC delimiter (CD)			1
+ * ACK slot (AS)			1
+ * ACK delimiter (AD)			1
+ * End-of-frame (EOF)			7
+ * Inter frame spacing			3
+ *
+ * assuming CRC21, rounded up and ignoring bitstuffing
+ */
+#define CANFD_FRAME_OVERHEAD_SFF DIV_ROUND_UP(61, 8)
+
+/*
+ * Size of a CAN-FD Extended Frame
+ *
+ * Name of Field			Bits
+ * ---------------------------------------------------------
+ * Start-of-frame			1
+ * Identifier A				11
+ * Substitute remote request (SRR)	1
+ * Identifier extension bit (IDE)	1
+ * Identifier B				18
+ * Reserved bit (r1)			1
+ * Flexible data rate format (FDF)	1
+ * Reserved bit (r0)			1
+ * Bit Rate Switch (BRS)		1
+ * Error Status Indicator (ESI)		1
+ * Data length code (DLC)		4
+ * Data field				0...512
+ * Stuff Bit Count (SBC)		0...16: 4 20...64:5
+ * CRC					0...16: 17 20...64:21
+ * CRC delimiter (CD)			1
+ * ACK slot (AS)			1
+ * ACK delimiter (AD)			1
+ * End-of-frame (EOF)			7
+ * Inter frame spacing			3
+ *
+ * assuming CRC21, rounded up and ignoring bitstuffing
+ */
+#define CANFD_FRAME_OVERHEAD_EFF DIV_ROUND_UP(80, 8)
+
+/*
+ * Maximum size of a Classical CAN frame
+ * (rounded up and ignoring bitstuffing)
+ */
+#define CAN_FRAME_LEN_MAX (CAN_FRAME_OVERHEAD_EFF + CAN_MAX_DLEN)
+
+/*
+ * Maximum size of a CAN-FD frame
+ * (rounded up and ignoring bitstuffing)
+ */
+#define CANFD_FRAME_LEN_MAX (CANFD_FRAME_OVERHEAD_EFF + CANFD_MAX_DLEN)
+
 /*
  * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
  * Classical CAN frame into a valid data length of max. 8 bytes.
@@ -45,6 +162,9 @@ u8 can_fd_dlc2len(u8 dlc);
 /* map the sanitized data length to an appropriate data length code */
 u8 can_fd_len2dlc(u8 len);
 
+/* calculate the CAN Frame length in bytes of a given skb */
+unsigned int can_skb_get_frame_len(const struct sk_buff *skb);
+
 /* map the data length to an appropriate data link layer length */
 static inline u8 canfd_sanitize_len(u8 len)
 {
-- 
2.29.2

Re: [net-next v2 10/15] can: length: can_skb_get_frame_len(): introduce function to get data length of frame in data link layer

[Vincent MAILHOL]

Le lun. 11 janv. 2021 à 19:45, Marc Kleine-Budde <mkl@pengutronix.de> a écrit :
>
> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>
> This patch adds the function can_skb_get_frame_len() which returns the length
> of a CAN frame on the data link layer, including Start-of-frame, Identifier,
> various other bits, the actual data, the CRC, the End-of-frame, the Inter frame
> spacing.
>
> Co-developed-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
> Not-Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
> Co-developed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Not-Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Co-developed-by: Marc Kleine-Budde <mkl@pengutronix.de>
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/net/can/dev/length.c |  50 +++++++++++++++
>  include/linux/can/length.h   | 120 +++++++++++++++++++++++++++++++++++
>  2 files changed, 170 insertions(+)
>
> diff --git a/drivers/net/can/dev/length.c b/drivers/net/can/dev/length.c
> index d695a3bee1ed..20cd153a45a5 100644
> --- a/drivers/net/can/dev/length.c
> +++ b/drivers/net/can/dev/length.c
> @@ -38,3 +38,53 @@ u8 can_fd_len2dlc(u8 len)
>         return len2dlc[len];
>  }
>  EXPORT_SYMBOL_GPL(can_fd_len2dlc);
> +
> +/**
> + * can_skb_get_frame_len() - Calculate the CAN Frame length in bytes
> + *     of a given skb.
> + * @skb: socket buffer of a CAN message.
> + *
> + * Do a rough calculation: bit stuffing is ignored and length in bits
> + * is rounded up to a length in bytes.
> + *
> + * Rationale: this function is to be used for the BQL functions
> + * (netdev_sent_queue() and netdev_completed_queue()) which expect a
> + * value in bytes. Just using skb->len is insufficient because it will
> + * return the constant value of CAN(FD)_MTU. Doing the bit stuffing
> + * calculation would be too expensive in term of computing resources
> + * for no noticeable gain.
> + *
> + * Remarks: The payload of CAN FD frames with BRS flag are sent at a
> + * different bitrate. Currently, the can-utils canbusload tool does
> + * not support CAN-FD yet and so we could not run any benchmark to
> + * measure the impact. There might be possible improvement here.
> + *
> + * Return: length in bytes.
> + */
> +unsigned int can_skb_get_frame_len(const struct sk_buff *skb)
> +{
> +       const struct canfd_frame *cf = (const struct canfd_frame *)skb->data;
> +       u8 len;
> +
> +       if (can_is_canfd_skb(skb))
> +               len = canfd_sanitize_len(cf->len);
> +       else if (cf->can_id & CAN_RTR_FLAG)
> +               len = 0;
> +       else
> +               len = cf->len;
> +
> +       if (can_is_canfd_skb(skb)) {
> +               if (cf->can_id & CAN_EFF_FLAG)
> +                       len += CANFD_FRAME_OVERHEAD_EFF;
> +               else
> +                       len += CANFD_FRAME_OVERHEAD_SFF;
> +       } else {
> +               if (cf->can_id & CAN_EFF_FLAG)
> +                       len += CAN_FRAME_OVERHEAD_EFF;
> +               else
> +                       len += CAN_FRAME_OVERHEAD_SFF;
> +       }
> +
> +       return len;
> +}
> +EXPORT_SYMBOL_GPL(can_skb_get_frame_len);
> diff --git a/include/linux/can/length.h b/include/linux/can/length.h
> index b2313b2a0b02..6995092b774e 100644
> --- a/include/linux/can/length.h
> +++ b/include/linux/can/length.h
> @@ -1,10 +1,127 @@
>  /* SPDX-License-Identifier: GPL-2.0 */
>  /* Copyright (C) 2020 Oliver Hartkopp <socketcan@hartkopp.net>
> + * Copyright (C) 2020 Marc Kleine-Budde <kernel@pengutronix.de>
>   */
>
>  #ifndef _CAN_LENGTH_H
>  #define _CAN_LENGTH_H
>
> +/*
> + * Size of a Classical CAN Standard Frame
> + *
> + * Name of Field                       Bits
> + * ---------------------------------------------------------
> + * Start-of-frame                      1
> + * Identifier                          11
> + * Remote transmission request (RTR)   1
> + * Identifier extension bit (IDE)      1
> + * Reserved bit (r0)                   1
> + * Data length code (DLC)              4
> + * Data field                          0...64
> + * CRC                                 15
> + * CRC delimiter                       1
> + * ACK slot                            1
> + * ACK delimiter                       1
> + * End-of-frame (EOF)                  7
> + * Inter frame spacing                 3
> + *
> + * rounded up and ignoring bitstuffing
> + */
> +#define CAN_FRAME_OVERHEAD_SFF DIV_ROUND_UP(47, 8)
> +
> +/*
> + * Size of a Classical CAN Extended Frame
> + *
> + * Name of Field                       Bits
> + * ---------------------------------------------------------
> + * Start-of-frame                      1
> + * Identifier A                                11
> + * Substitute remote request (SRR)     1
> + * Identifier extension bit (IDE)      1
> + * Identifier B                                18
> + * Remote transmission request (RTR)   1
> + * Reserved bits (r1, r0)              2
> + * Data length code (DLC)              4
> + * Data field                          0...64
> + * CRC                                 15
> + * CRC delimiter                       1
> + * ACK slot                            1
> + * ACK delimiter                       1
> + * End-of-frame (EOF)                  7
> + * Inter frame spacing                 3
> + *
> + * rounded up and ignoring bitstuffing
> + */
> +#define CAN_FRAME_OVERHEAD_EFF DIV_ROUND_UP(67, 8)
> +
> +/*
> + * Size of a CAN-FD Standard Frame
> + *
> + * Name of Field                       Bits
> + * ---------------------------------------------------------
> + * Start-of-frame                      1
> + * Identifier                          11
> + * Reserved bit (r1)                   1
> + * Identifier extension bit (IDE)      1
> + * Flexible data rate format (FDF)     1
> + * Reserved bit (r0)                   1
> + * Bit Rate Switch (BRS)               1
> + * Error Status Indicator (ESI)                1
> + * Data length code (DLC)              4
> + * Data field                          0...512
> + * Stuff Bit Count (SBC)               0...16: 4 20...64:5
> + * CRC                                 0...16: 17 20...64:21
> + * CRC delimiter (CD)                  1
> + * ACK slot (AS)                       1
> + * ACK delimiter (AD)                  1
> + * End-of-frame (EOF)                  7
> + * Inter frame spacing                 3
> + *
> + * assuming CRC21, rounded up and ignoring bitstuffing
> + */
> +#define CANFD_FRAME_OVERHEAD_SFF DIV_ROUND_UP(61, 8)
> +
> +/*
> + * Size of a CAN-FD Extended Frame
> + *
> + * Name of Field                       Bits
> + * ---------------------------------------------------------
> + * Start-of-frame                      1
> + * Identifier A                                11
> + * Substitute remote request (SRR)     1
> + * Identifier extension bit (IDE)      1
> + * Identifier B                                18
> + * Reserved bit (r1)                   1
> + * Flexible data rate format (FDF)     1
> + * Reserved bit (r0)                   1
> + * Bit Rate Switch (BRS)               1
> + * Error Status Indicator (ESI)                1
> + * Data length code (DLC)              4
> + * Data field                          0...512
> + * Stuff Bit Count (SBC)               0...16: 4 20...64:5
> + * CRC                                 0...16: 17 20...64:21
> + * CRC delimiter (CD)                  1
> + * ACK slot (AS)                       1
> + * ACK delimiter (AD)                  1
> + * End-of-frame (EOF)                  7
> + * Inter frame spacing                 3
> + *
> + * assuming CRC21, rounded up and ignoring bitstuffing
> + */
> +#define CANFD_FRAME_OVERHEAD_EFF DIV_ROUND_UP(80, 8)
> +
> +/*
> + * Maximum size of a Classical CAN frame
> + * (rounded up and ignoring bitstuffing)
> + */
> +#define CAN_FRAME_LEN_MAX (CAN_FRAME_OVERHEAD_EFF + CAN_MAX_DLEN)
> +
> +/*
> + * Maximum size of a CAN-FD frame
> + * (rounded up and ignoring bitstuffing)
> + */
> +#define CANFD_FRAME_LEN_MAX (CANFD_FRAME_OVERHEAD_EFF + CANFD_MAX_DLEN)
> +
>  /*
>   * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
>   * Classical CAN frame into a valid data length of max. 8 bytes.
> @@ -45,6 +162,9 @@ u8 can_fd_dlc2len(u8 dlc);
>  /* map the sanitized data length to an appropriate data length code */
>  u8 can_fd_len2dlc(u8 len);
>
> +/* calculate the CAN Frame length in bytes of a given skb */
> +unsigned int can_skb_get_frame_len(const struct sk_buff *skb);
> +
>  /* map the data length to an appropriate data link layer length */
>  static inline u8 canfd_sanitize_len(u8 len)
>  {
> --
> 2.29.2
>

Signed-off-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Thanks Marc!

[net-next v2 11/15] can: dev: extend struct can_skb_priv to hold CAN frame length

[Marc Kleine-Budde]

In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend the struct can_skb_priv to hold
the length of the CAN frame and extend __can_get_echo_skb() to return that
value.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/rx-offload.c | 2 +-
 drivers/net/can/dev/skb.c        | 9 +++++++--
 include/linux/can/skb.h          | 4 +++-
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c
index 3c1912c0430b..6a26b5282df1 100644
--- a/drivers/net/can/dev/rx-offload.c
+++ b/drivers/net/can/dev/rx-offload.c
@@ -271,7 +271,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
 	u8 len;
 	int err;
 
-	skb = __can_get_echo_skb(dev, idx, &len);
+	skb = __can_get_echo_skb(dev, idx, &len, NULL);
 	if (!skb)
 		return 0;
 
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 26cd597ff771..24f782a23409 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -76,7 +76,8 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 EXPORT_SYMBOL_GPL(can_put_echo_skb);
 
 struct sk_buff *
-__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
+__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
+		   unsigned int *frame_len_ptr)
 {
 	struct can_priv *priv = netdev_priv(dev);
 
@@ -91,6 +92,7 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 		 * length is supported on both CAN and CANFD frames.
 		 */
 		struct sk_buff *skb = priv->echo_skb[idx];
+		struct can_skb_priv *can_skb_priv = can_skb_prv(skb);
 		struct canfd_frame *cf = (struct canfd_frame *)skb->data;
 
 		/* get the real payload length for netdev statistics */
@@ -99,6 +101,9 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr)
 		else
 			*len_ptr = cf->len;
 
+		if (frame_len_ptr)
+			*frame_len_ptr = can_skb_priv->frame_len;
+
 		priv->echo_skb[idx] = NULL;
 
 		return skb;
@@ -118,7 +123,7 @@ unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 	struct sk_buff *skb;
 	u8 len;
 
-	skb = __can_get_echo_skb(dev, idx, &len);
+	skb = __can_get_echo_skb(dev, idx, &len, NULL);
 	if (!skb)
 		return 0;
 
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index c90ebbd3008c..5db9da30843c 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -20,7 +20,7 @@ void can_flush_echo_skb(struct net_device *dev);
 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 		     unsigned int idx);
 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
-				   u8 *len_ptr);
+				   u8 *len_ptr, unsigned int *frame_len_ptr);
 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
@@ -42,11 +42,13 @@ struct sk_buff *alloc_can_err_skb(struct net_device *dev,
  * struct can_skb_priv - private additional data inside CAN sk_buffs
  * @ifindex:	ifindex of the first interface the CAN frame appeared on
  * @skbcnt:	atomic counter to have an unique id together with skb pointer
+ * @frame_len:	length of CAN frame in data link layer
  * @cf:		align to the following CAN frame at skb->data
  */
 struct can_skb_priv {
 	int ifindex;
 	int skbcnt;
+	unsigned int frame_len;
 	struct can_frame cf[];
 };
 
-- 
2.29.2

[net-next v2 12/15] can: dev: can_put_echo_skb(): extend to handle frame_len

[Marc Kleine-Budde]

From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Add a frame_len argument to can_put_echo_skb() which is used to save length of
the CAN frame into field frame_len of struct can_skb_priv so that it can be
later used after transmission completion. Convert all users of this function,
too.

Drivers which implement BQL call can_put_echo_skb() with the output of
can_skb_get_frame_len(skb) and drivers which do not simply pass zero as an
input (in the same way that NULL would be given to can_get_echo_skb()). This
way, we have a nice symmetry between the two echo functions.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210111061335.39983-1-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/at91_can.c                       | 2 +-
 drivers/net/can/c_can/c_can.c                    | 2 +-
 drivers/net/can/cc770/cc770.c                    | 2 +-
 drivers/net/can/dev/skb.c                        | 5 ++++-
 drivers/net/can/flexcan.c                        | 2 +-
 drivers/net/can/grcan.c                          | 2 +-
 drivers/net/can/ifi_canfd/ifi_canfd.c            | 2 +-
 drivers/net/can/kvaser_pciefd.c                  | 2 +-
 drivers/net/can/m_can/m_can.c                    | 4 ++--
 drivers/net/can/mscan/mscan.c                    | 2 +-
 drivers/net/can/pch_can.c                        | 2 +-
 drivers/net/can/peak_canfd/peak_canfd.c          | 2 +-
 drivers/net/can/rcar/rcar_can.c                  | 2 +-
 drivers/net/can/rcar/rcar_canfd.c                | 2 +-
 drivers/net/can/sja1000/sja1000.c                | 2 +-
 drivers/net/can/softing/softing_main.c           | 2 +-
 drivers/net/can/spi/hi311x.c                     | 2 +-
 drivers/net/can/spi/mcp251x.c                    | 2 +-
 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c   | 2 +-
 drivers/net/can/sun4i_can.c                      | 2 +-
 drivers/net/can/ti_hecc.c                        | 2 +-
 drivers/net/can/usb/ems_usb.c                    | 2 +-
 drivers/net/can/usb/esd_usb2.c                   | 2 +-
 drivers/net/can/usb/gs_usb.c                     | 2 +-
 drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c | 2 +-
 drivers/net/can/usb/mcba_usb.c                   | 2 +-
 drivers/net/can/usb/peak_usb/pcan_usb_core.c     | 2 +-
 drivers/net/can/usb/ucan.c                       | 2 +-
 drivers/net/can/usb/usb_8dev.c                   | 2 +-
 drivers/net/can/xilinx_can.c                     | 4 ++--
 include/linux/can/skb.h                          | 2 +-
 31 files changed, 36 insertions(+), 33 deletions(-)

diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 5284f0ab3b06..90b223a80ed4 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -484,7 +484,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	stats->tx_bytes += cf->len;
 
 	/* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
-	can_put_echo_skb(skb, dev, mb - get_mb_tx_first(priv));
+	can_put_echo_skb(skb, dev, mb - get_mb_tx_first(priv), 0);
 
 	/*
 	 * we have to stop the queue and deliver all messages in case
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 63f48b016ecd..13638954a25c 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -476,7 +476,7 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb,
 	 */
 	c_can_setup_tx_object(dev, IF_TX, frame, idx);
 	priv->dlc[idx] = frame->len;
-	can_put_echo_skb(skb, dev, idx);
+	can_put_echo_skb(skb, dev, idx, 0);
 
 	/* Update the active bits */
 	atomic_add((1 << idx), &priv->tx_active);
diff --git a/drivers/net/can/cc770/cc770.c b/drivers/net/can/cc770/cc770.c
index 8d9f332c35e0..e53ca338368a 100644
--- a/drivers/net/can/cc770/cc770.c
+++ b/drivers/net/can/cc770/cc770.c
@@ -702,7 +702,7 @@ static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
 	stats->tx_bytes += cf->len;
 	stats->tx_packets++;
 
-	can_put_echo_skb(priv->tx_skb, dev, 0);
+	can_put_echo_skb(priv->tx_skb, dev, 0, 0);
 	can_get_echo_skb(dev, 0);
 	priv->tx_skb = NULL;
 
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 24f782a23409..c184b4dce19e 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -38,7 +38,7 @@ void can_flush_echo_skb(struct net_device *dev)
  * priv->echo_skb, if necessary.
  */
 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
-		     unsigned int idx)
+		     unsigned int idx, unsigned int frame_len)
 {
 	struct can_priv *priv = netdev_priv(dev);
 
@@ -62,6 +62,9 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 		skb->dev = dev;
 
+		/* save frame_len to reuse it when transmission is completed */
+		can_skb_prv(skb)->frame_len = frame_len;
+
 		/* save this skb for tx interrupt echo handling */
 		priv->echo_skb[idx] = skb;
 	} else {
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 7ab20a6b0d1d..202d08f8e1a4 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -815,7 +815,7 @@ static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *de
 		priv->write(data, &priv->tx_mb->data[i / sizeof(u32)]);
 	}
 
-	can_put_echo_skb(skb, dev, 0);
+	can_put_echo_skb(skb, dev, 0, 0);
 
 	priv->write(can_id, &priv->tx_mb->can_id);
 	priv->write(ctrl, &priv->tx_mb->can_ctrl);
diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index f5d94a692576..8086cdc10000 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -1448,7 +1448,7 @@ static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
 	 * taken.
 	 */
 	priv->txdlc[slotindex] = cf->len; /* Store dlc for statistics */
-	can_put_echo_skb(skb, dev, slotindex);
+	can_put_echo_skb(skb, dev, slotindex, 0);
 
 	/* Make sure everything is written before allowing hardware to
 	 * read from the memory
diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 86b0e1406a21..56ac9e1dace7 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -922,7 +922,7 @@ static netdev_tx_t ifi_canfd_start_xmit(struct sk_buff *skb,
 	writel(0, priv->base + IFI_CANFD_TXFIFO_REPEATCOUNT);
 	writel(0, priv->base + IFI_CANFD_TXFIFO_SUSPEND_US);
 
-	can_put_echo_skb(skb, ndev, 0);
+	can_put_echo_skb(skb, ndev, 0, 0);
 
 	/* Start the transmission */
 	writel(IFI_CANFD_TXSTCMD_ADD_MSG, priv->base + IFI_CANFD_TXSTCMD);
diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 969cedb9b0b6..0cf82f0646a3 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -778,7 +778,7 @@ static netdev_tx_t kvaser_pciefd_start_xmit(struct sk_buff *skb,
 	spin_lock_irqsave(&can->echo_lock, irq_flags);
 
 	/* Prepare and save echo skb in internal slot */
-	can_put_echo_skb(skb, netdev, can->echo_idx);
+	can_put_echo_skb(skb, netdev, can->echo_idx, 0);
 
 	/* Move echo index to the next slot */
 	can->echo_idx = (can->echo_idx + 1) % can->can.echo_skb_max;
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index da551fd0f502..fff7432103cb 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1483,7 +1483,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 					 M_CAN_FIFO_DATA(i / 4),
 					 *(u32 *)(cf->data + i));
 
-		can_put_echo_skb(skb, dev, 0);
+		can_put_echo_skb(skb, dev, 0, 0);
 
 		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
 			cccr = m_can_read(cdev, M_CAN_CCCR);
@@ -1554,7 +1554,7 @@ static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 		/* Push loopback echo.
 		 * Will be looped back on TX interrupt based on message marker
 		 */
-		can_put_echo_skb(skb, dev, putidx);
+		can_put_echo_skb(skb, dev, putidx, 0);
 
 		/* Enable TX FIFO element to start transfer  */
 		m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index 5ed00a1558e1..a28fdaa411c6 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -270,7 +270,7 @@ static netdev_tx_t mscan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	list_add_tail(&priv->tx_queue[buf_id].list, &priv->tx_head);
 
-	can_put_echo_skb(skb, dev, buf_id);
+	can_put_echo_skb(skb, dev, buf_id, 0);
 
 	/* Enable interrupt. */
 	priv->tx_active |= 1 << buf_id;
diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 4f9e7ec192aa..a4c35b48d8e9 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -924,7 +924,7 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
 			  &priv->regs->ifregs[1].data[i / 2]);
 	}
 
-	can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1);
+	can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1, 0);
 
 	/* Set the size of the data. Update if2_mcont */
 	iowrite32(cf->len | PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT |
diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c
index c5334b0c3038..179a8e10fbb8 100644
--- a/drivers/net/can/peak_canfd/peak_canfd.c
+++ b/drivers/net/can/peak_canfd/peak_canfd.c
@@ -716,7 +716,7 @@ static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
 	spin_lock_irqsave(&priv->echo_lock, flags);
 
 	/* prepare and save echo skb in internal slot */
-	can_put_echo_skb(skb, ndev, priv->echo_idx);
+	can_put_echo_skb(skb, ndev, priv->echo_idx, 0);
 
 	/* move echo index to the next slot */
 	priv->echo_idx = (priv->echo_idx + 1) % priv->can.echo_skb_max;
diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c
index c803327f8f79..0b7e488bc4fe 100644
--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -617,7 +617,7 @@ static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
 	writeb(cf->len, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
 
 	priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->len;
-	can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
+	can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH, 0);
 	priv->tx_head++;
 	/* Start Tx: write 0xff to the TFPCR register to increment
 	 * the CPU-side pointer for the transmit FIFO to the next
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 2778ed5c61d1..38376f29bc56 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1390,7 +1390,7 @@ static netdev_tx_t rcar_canfd_start_xmit(struct sk_buff *skb,
 	}
 
 	priv->tx_len[priv->tx_head % RCANFD_FIFO_DEPTH] = cf->len;
-	can_put_echo_skb(skb, ndev, priv->tx_head % RCANFD_FIFO_DEPTH);
+	can_put_echo_skb(skb, ndev, priv->tx_head % RCANFD_FIFO_DEPTH, 0);
 
 	spin_lock_irqsave(&priv->tx_lock, flags);
 	priv->tx_head++;
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index b6a7003c51d2..e98482c7bf33 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -318,7 +318,7 @@ static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
 	for (i = 0; i < cf->len; i++)
 		priv->write_reg(priv, dreg++, cf->data[i]);
 
-	can_put_echo_skb(skb, dev, 0);
+	can_put_echo_skb(skb, dev, 0, 0);
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 		cmd_reg_val |= CMD_AT;
diff --git a/drivers/net/can/softing/softing_main.c b/drivers/net/can/softing/softing_main.c
index 40070c930202..a5314448c5ae 100644
--- a/drivers/net/can/softing/softing_main.c
+++ b/drivers/net/can/softing/softing_main.c
@@ -104,7 +104,7 @@ static netdev_tx_t softing_netdev_start_xmit(struct sk_buff *skb,
 	card->tx.last_bus = priv->index;
 	++card->tx.pending;
 	++priv->tx.pending;
-	can_put_echo_skb(skb, dev, priv->tx.echo_put);
+	can_put_echo_skb(skb, dev, priv->tx.echo_put, 0);
 	++priv->tx.echo_put;
 	if (priv->tx.echo_put >= TX_ECHO_SKB_MAX)
 		priv->tx.echo_put = 0;
diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
index f9455de94786..8c83a9e5a9e4 100644
--- a/drivers/net/can/spi/hi311x.c
+++ b/drivers/net/can/spi/hi311x.c
@@ -586,7 +586,7 @@ static void hi3110_tx_work_handler(struct work_struct *ws)
 			frame = (struct can_frame *)priv->tx_skb->data;
 			hi3110_hw_tx(spi, frame);
 			priv->tx_len = 1 + frame->len;
-			can_put_echo_skb(priv->tx_skb, net, 0);
+			can_put_echo_skb(priv->tx_skb, net, 0, 0);
 			priv->tx_skb = NULL;
 		}
 	}
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 25859d16d06f..40866754aafc 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -1002,7 +1002,7 @@ static void mcp251x_tx_work_handler(struct work_struct *ws)
 				frame->len = CAN_FRAME_MAX_DATA_LEN;
 			mcp251x_hw_tx(spi, frame, 0);
 			priv->tx_len = 1 + frame->len;
-			can_put_echo_skb(priv->tx_skb, net, 0);
+			can_put_echo_skb(priv->tx_skb, net, 0, 0);
 			priv->tx_skb = NULL;
 		}
 	}
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 36235afb0bc6..95bba456a4cd 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -2436,7 +2436,7 @@ static netdev_tx_t mcp251xfd_start_xmit(struct sk_buff *skb,
 	if (tx_ring->head - tx_ring->tail >= tx_ring->obj_num)
 		netif_stop_queue(ndev);
 
-	can_put_echo_skb(skb, ndev, tx_head);
+	can_put_echo_skb(skb, ndev, tx_head, 0);
 
 	err = mcp251xfd_tx_obj_write(priv, tx_obj);
 	if (err)
diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
index 783b63218b7b..b75175d59104 100644
--- a/drivers/net/can/sun4i_can.c
+++ b/drivers/net/can/sun4i_can.c
@@ -448,7 +448,7 @@ static netdev_tx_t sun4ican_start_xmit(struct sk_buff *skb, struct net_device *d
 
 	writel(msg_flag_n, priv->base + SUN4I_REG_BUF0_ADDR);
 
-	can_put_echo_skb(skb, dev, 0);
+	can_put_echo_skb(skb, dev, 0, 0);
 
 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 		sun4i_can_write_cmdreg(priv, SUN4I_CMD_SELF_RCV_REQ);
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index a6850ff0b55b..485c19bc98c2 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -513,7 +513,7 @@ static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev)
 			       be32_to_cpu(*(__be32 *)(cf->data + 4)));
 	else
 		*(u32 *)(cf->data + 4) = 0;
-	can_put_echo_skb(skb, ndev, mbxno);
+	can_put_echo_skb(skb, ndev, mbxno, 0);
 
 	spin_lock_irqsave(&priv->mbx_lock, flags);
 	--priv->tx_head;
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 25eee4466364..5e5330060464 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -801,7 +801,7 @@ static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *ne
 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	usb_anchor_urb(urb, &dev->tx_submitted);
 
-	can_put_echo_skb(skb, netdev, context->echo_index);
+	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 
 	atomic_inc(&dev->active_tx_urbs);
 
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index 9eed75a4b678..68d8a85f00c4 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -783,7 +783,7 @@ static netdev_tx_t esd_usb2_start_xmit(struct sk_buff *skb,
 
 	usb_anchor_urb(urb, &priv->tx_submitted);
 
-	can_put_echo_skb(skb, netdev, context->echo_index);
+	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 
 	atomic_inc(&priv->active_tx_jobs);
 
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 0487095e1fd0..5ce9ba5d29d6 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -525,7 +525,7 @@ static netdev_tx_t gs_can_start_xmit(struct sk_buff *skb,
 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	usb_anchor_urb(urb, &dev->tx_submitted);
 
-	can_put_echo_skb(skb, netdev, idx);
+	can_put_echo_skb(skb, netdev, idx, 0);
 
 	atomic_inc(&dev->active_tx_urbs);
 
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
index e2d58846c40c..2b7efd296758 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -578,7 +578,7 @@ static netdev_tx_t kvaser_usb_start_xmit(struct sk_buff *skb,
 
 	context->priv = priv;
 
-	can_put_echo_skb(skb, netdev, context->echo_index);
+	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 
 	usb_fill_bulk_urb(urb, dev->udev,
 			  usb_sndbulkpipe(dev->udev,
diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
index df54eb7d4b36..5347c89992ce 100644
--- a/drivers/net/can/usb/mcba_usb.c
+++ b/drivers/net/can/usb/mcba_usb.c
@@ -355,7 +355,7 @@ static netdev_tx_t mcba_usb_start_xmit(struct sk_buff *skb,
 	if (cf->can_id & CAN_RTR_FLAG)
 		usb_msg.dlc |= MCBA_DLC_RTR_MASK;
 
-	can_put_echo_skb(skb, priv->netdev, ctx->ndx);
+	can_put_echo_skb(skb, priv->netdev, ctx->ndx, 0);
 
 	err = mcba_usb_xmit(priv, (struct mcba_usb_msg *)&usb_msg, ctx);
 	if (err)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index 251835ea15aa..95672750419a 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -365,7 +365,7 @@ static netdev_tx_t peak_usb_ndo_start_xmit(struct sk_buff *skb,
 
 	usb_anchor_urb(urb, &dev->tx_submitted);
 
-	can_put_echo_skb(skb, netdev, context->echo_index);
+	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 
 	atomic_inc(&dev->active_tx_urbs);
 
diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index 7d92da8954fe..5add27614e2b 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -1137,7 +1137,7 @@ static netdev_tx_t ucan_start_xmit(struct sk_buff *skb,
 
 	/* put the skb on can loopback stack */
 	spin_lock_irqsave(&up->echo_skb_lock, flags);
-	can_put_echo_skb(skb, up->netdev, echo_index);
+	can_put_echo_skb(skb, up->netdev, echo_index, 0);
 	spin_unlock_irqrestore(&up->echo_skb_lock, flags);
 
 	/* transmit it */
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index 44478304ff46..2e824d9d8167 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -664,7 +664,7 @@ static netdev_tx_t usb_8dev_start_xmit(struct sk_buff *skb,
 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	usb_anchor_urb(urb, &priv->tx_submitted);
 
-	can_put_echo_skb(skb, netdev, context->echo_index);
+	can_put_echo_skb(skb, netdev, context->echo_index, 0);
 
 	atomic_inc(&priv->active_tx_urbs);
 
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 3f54edee92eb..8d5132a3f2c9 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -592,9 +592,9 @@ static void xcan_write_frame(struct net_device *ndev, struct sk_buff *skb,
 
 	if (!(priv->devtype.flags & XCAN_FLAG_TX_MAILBOXES) &&
 	    (priv->devtype.flags & XCAN_FLAG_TXFEMP))
-		can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
+		can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max, 0);
 	else
-		can_put_echo_skb(skb, ndev, 0);
+		can_put_echo_skb(skb, ndev, 0, 0);
 
 	priv->tx_head++;
 
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index 5db9da30843c..eaac4a637ae0 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -18,7 +18,7 @@
 
 void can_flush_echo_skb(struct net_device *dev);
 int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
-		     unsigned int idx);
+		     unsigned int idx, unsigned int frame_len);
 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 				   u8 *len_ptr, unsigned int *frame_len_ptr);
 unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
-- 
2.29.2

[net-next v2 13/15] can: dev: can_get_echo_skb(): extend to return can frame length

[Marc Kleine-Budde]

In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_get_echo_skb() to return
that value. Convert all users of this function, too.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/at91_can.c                        | 2 +-
 drivers/net/can/c_can/c_can.c                     | 2 +-
 drivers/net/can/cc770/cc770.c                     | 2 +-
 drivers/net/can/dev/skb.c                         | 5 +++--
 drivers/net/can/grcan.c                           | 2 +-
 drivers/net/can/ifi_canfd/ifi_canfd.c             | 2 +-
 drivers/net/can/kvaser_pciefd.c                   | 4 ++--
 drivers/net/can/m_can/m_can.c                     | 4 ++--
 drivers/net/can/mscan/mscan.c                     | 2 +-
 drivers/net/can/pch_can.c                         | 2 +-
 drivers/net/can/peak_canfd/peak_canfd.c           | 2 +-
 drivers/net/can/rcar/rcar_can.c                   | 2 +-
 drivers/net/can/rcar/rcar_canfd.c                 | 2 +-
 drivers/net/can/sja1000/sja1000.c                 | 2 +-
 drivers/net/can/softing/softing_main.c            | 2 +-
 drivers/net/can/spi/hi311x.c                      | 2 +-
 drivers/net/can/spi/mcp251x.c                     | 2 +-
 drivers/net/can/sun4i_can.c                       | 2 +-
 drivers/net/can/usb/ems_usb.c                     | 2 +-
 drivers/net/can/usb/esd_usb2.c                    | 2 +-
 drivers/net/can/usb/gs_usb.c                      | 2 +-
 drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c | 2 +-
 drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c  | 2 +-
 drivers/net/can/usb/mcba_usb.c                    | 2 +-
 drivers/net/can/usb/peak_usb/pcan_usb_core.c      | 2 +-
 drivers/net/can/usb/ucan.c                        | 2 +-
 drivers/net/can/usb/usb_8dev.c                    | 2 +-
 drivers/net/can/xilinx_can.c                      | 2 +-
 include/linux/can/skb.h                           | 3 ++-
 29 files changed, 34 insertions(+), 32 deletions(-)

diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 90b223a80ed4..9ad9b39f480e 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -856,7 +856,7 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr)
 		if (likely(reg_msr & AT91_MSR_MRDY &&
 			   ~reg_msr & AT91_MSR_MABT)) {
 			/* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
-			can_get_echo_skb(dev, mb - get_mb_tx_first(priv));
+			can_get_echo_skb(dev, mb - get_mb_tx_first(priv), NULL);
 			dev->stats.tx_packets++;
 			can_led_event(dev, CAN_LED_EVENT_TX);
 		}
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index 13638954a25c..ef474bae47a1 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -733,7 +733,7 @@ static void c_can_do_tx(struct net_device *dev)
 		pend &= ~(1 << idx);
 		obj = idx + C_CAN_MSG_OBJ_TX_FIRST;
 		c_can_inval_tx_object(dev, IF_RX, obj);
-		can_get_echo_skb(dev, idx);
+		can_get_echo_skb(dev, idx, NULL);
 		bytes += priv->dlc[idx];
 		pkts++;
 	}
diff --git a/drivers/net/can/cc770/cc770.c b/drivers/net/can/cc770/cc770.c
index e53ca338368a..f8a130f594e2 100644
--- a/drivers/net/can/cc770/cc770.c
+++ b/drivers/net/can/cc770/cc770.c
@@ -703,7 +703,7 @@ static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
 	stats->tx_packets++;
 
 	can_put_echo_skb(priv->tx_skb, dev, 0, 0);
-	can_get_echo_skb(dev, 0);
+	can_get_echo_skb(dev, 0, NULL);
 	priv->tx_skb = NULL;
 
 	netif_wake_queue(dev);
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index c184b4dce19e..53683d4312f1 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -121,12 +121,13 @@ __can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 *len_ptr,
  * is handled in the device driver. The driver must protect
  * access to priv->echo_skb, if necessary.
  */
-unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
+			      unsigned int *frame_len_ptr)
 {
 	struct sk_buff *skb;
 	u8 len;
 
-	skb = __can_get_echo_skb(dev, idx, &len, NULL);
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
 	if (!skb)
 		return 0;
 
diff --git a/drivers/net/can/grcan.c b/drivers/net/can/grcan.c
index 8086cdc10000..4a8453290530 100644
--- a/drivers/net/can/grcan.c
+++ b/drivers/net/can/grcan.c
@@ -517,7 +517,7 @@ static int catch_up_echo_skb(struct net_device *dev, int budget, bool echo)
 			stats->tx_packets++;
 			stats->tx_bytes += priv->txdlc[i];
 			priv->txdlc[i] = 0;
-			can_get_echo_skb(dev, i);
+			can_get_echo_skb(dev, i, NULL);
 		} else {
 			/* For cleanup of untransmitted messages */
 			can_free_echo_skb(dev, i);
diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 56ac9e1dace7..5bb957a26bc6 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -629,7 +629,7 @@ static irqreturn_t ifi_canfd_isr(int irq, void *dev_id)
 
 	/* TX IRQ */
 	if (isr & IFI_CANFD_INTERRUPT_TXFIFO_REMOVE) {
-		stats->tx_bytes += can_get_echo_skb(ndev, 0);
+		stats->tx_bytes += can_get_echo_skb(ndev, 0, NULL);
 		stats->tx_packets++;
 		can_led_event(ndev, CAN_LED_EVENT_TX);
 	}
diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 0cf82f0646a3..37e05010ca91 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -1467,7 +1467,7 @@ static int kvaser_pciefd_handle_eack_packet(struct kvaser_pciefd *pcie,
 				  can->reg_base + KVASER_PCIEFD_KCAN_CTRL_REG);
 	} else {
 		int echo_idx = p->header[0] & KVASER_PCIEFD_PACKET_SEQ_MSK;
-		int dlc = can_get_echo_skb(can->can.dev, echo_idx);
+		int dlc = can_get_echo_skb(can->can.dev, echo_idx, NULL);
 		struct net_device_stats *stats = &can->can.dev->stats;
 
 		stats->tx_bytes += dlc;
@@ -1533,7 +1533,7 @@ static int kvaser_pciefd_handle_ack_packet(struct kvaser_pciefd *pcie,
 		netdev_dbg(can->can.dev, "Packet was flushed\n");
 	} else {
 		int echo_idx = p->header[0] & KVASER_PCIEFD_PACKET_SEQ_MSK;
-		int dlc = can_get_echo_skb(can->can.dev, echo_idx);
+		int dlc = can_get_echo_skb(can->can.dev, echo_idx, NULL);
 		u8 count = ioread32(can->reg_base +
 				    KVASER_PCIEFD_KCAN_TX_NPACKETS_REG) & 0xff;
 
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index fff7432103cb..3752520a7d4b 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -930,7 +930,7 @@ static void m_can_echo_tx_event(struct net_device *dev)
 						(fgi << TXEFA_EFAI_SHIFT)));
 
 		/* update stats */
-		stats->tx_bytes += can_get_echo_skb(dev, msg_mark);
+		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
 		stats->tx_packets++;
 	}
 }
@@ -972,7 +972,7 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	if (cdev->version == 30) {
 		if (ir & IR_TC) {
 			/* Transmission Complete Interrupt*/
-			stats->tx_bytes += can_get_echo_skb(dev, 0);
+			stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
 			stats->tx_packets++;
 			can_led_event(dev, CAN_LED_EVENT_TX);
 			netif_wake_queue(dev);
diff --git a/drivers/net/can/mscan/mscan.c b/drivers/net/can/mscan/mscan.c
index a28fdaa411c6..fa32e418eb29 100644
--- a/drivers/net/can/mscan/mscan.c
+++ b/drivers/net/can/mscan/mscan.c
@@ -448,7 +448,7 @@ static irqreturn_t mscan_isr(int irq, void *dev_id)
 			out_8(&regs->cantbsel, mask);
 			stats->tx_bytes += in_8(&regs->tx.dlr);
 			stats->tx_packets++;
-			can_get_echo_skb(dev, entry->id);
+			can_get_echo_skb(dev, entry->id, NULL);
 			priv->tx_active &= ~mask;
 			list_del(pos);
 		}
diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index a4c35b48d8e9..92a54a5fd4c5 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -711,7 +711,7 @@ static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
 	struct net_device_stats *stats = &(priv->ndev->stats);
 	u32 dlc;
 
-	can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
+	can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1, NULL);
 	iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
 		  &priv->regs->ifregs[1].cmask);
 	pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, int_stat);
diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c
index 179a8e10fbb8..00847cbaf7b6 100644
--- a/drivers/net/can/peak_canfd/peak_canfd.c
+++ b/drivers/net/can/peak_canfd/peak_canfd.c
@@ -266,7 +266,7 @@ static int pucan_handle_can_rx(struct peak_canfd_priv *priv,
 		unsigned long flags;
 
 		spin_lock_irqsave(&priv->echo_lock, flags);
-		can_get_echo_skb(priv->ndev, msg->client);
+		can_get_echo_skb(priv->ndev, msg->client, NULL);
 
 		/* count bytes of the echo instead of skb */
 		stats->tx_bytes += cf_len;
diff --git a/drivers/net/can/rcar/rcar_can.c b/drivers/net/can/rcar/rcar_can.c
index 0b7e488bc4fe..4870c4ea190a 100644
--- a/drivers/net/can/rcar/rcar_can.c
+++ b/drivers/net/can/rcar/rcar_can.c
@@ -386,7 +386,7 @@ static void rcar_can_tx_done(struct net_device *ndev)
 		stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
 						RCAR_CAN_FIFO_DEPTH];
 		priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
-		can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
+		can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH, NULL);
 		priv->tx_tail++;
 		netif_wake_queue(ndev);
 	}
diff --git a/drivers/net/can/rcar/rcar_canfd.c b/drivers/net/can/rcar/rcar_canfd.c
index 38376f29bc56..d8d233e62990 100644
--- a/drivers/net/can/rcar/rcar_canfd.c
+++ b/drivers/net/can/rcar/rcar_canfd.c
@@ -1044,7 +1044,7 @@ static void rcar_canfd_tx_done(struct net_device *ndev)
 		stats->tx_packets++;
 		stats->tx_bytes += priv->tx_len[sent];
 		priv->tx_len[sent] = 0;
-		can_get_echo_skb(ndev, sent);
+		can_get_echo_skb(ndev, sent, NULL);
 
 		spin_lock_irqsave(&priv->tx_lock, flags);
 		priv->tx_tail++;
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index e98482c7bf33..9e86488ba55f 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c
@@ -531,7 +531,7 @@ irqreturn_t sja1000_interrupt(int irq, void *dev_id)
 				stats->tx_bytes +=
 					priv->read_reg(priv, SJA1000_FI) & 0xf;
 				stats->tx_packets++;
-				can_get_echo_skb(dev, 0);
+				can_get_echo_skb(dev, 0, NULL);
 			}
 			netif_wake_queue(dev);
 			can_led_event(dev, CAN_LED_EVENT_TX);
diff --git a/drivers/net/can/softing/softing_main.c b/drivers/net/can/softing/softing_main.c
index a5314448c5ae..c44f3411e561 100644
--- a/drivers/net/can/softing/softing_main.c
+++ b/drivers/net/can/softing/softing_main.c
@@ -284,7 +284,7 @@ static int softing_handle_1(struct softing *card)
 			skb = priv->can.echo_skb[priv->tx.echo_get];
 			if (skb)
 				skb->tstamp = ktime;
-			can_get_echo_skb(netdev, priv->tx.echo_get);
+			can_get_echo_skb(netdev, priv->tx.echo_get, NULL);
 			++priv->tx.echo_get;
 			if (priv->tx.echo_get >= TX_ECHO_SKB_MAX)
 				priv->tx.echo_get = 0;
diff --git a/drivers/net/can/spi/hi311x.c b/drivers/net/can/spi/hi311x.c
index 8c83a9e5a9e4..c3e020c90111 100644
--- a/drivers/net/can/spi/hi311x.c
+++ b/drivers/net/can/spi/hi311x.c
@@ -725,7 +725,7 @@ static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 			net->stats.tx_bytes += priv->tx_len - 1;
 			can_led_event(net, CAN_LED_EVENT_TX);
 			if (priv->tx_len) {
-				can_get_echo_skb(net, 0);
+				can_get_echo_skb(net, 0, NULL);
 				priv->tx_len = 0;
 			}
 			netif_wake_queue(net);
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 40866754aafc..f69fb4238a65 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -1171,7 +1171,7 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
 			net->stats.tx_bytes += priv->tx_len - 1;
 			can_led_event(net, CAN_LED_EVENT_TX);
 			if (priv->tx_len) {
-				can_get_echo_skb(net, 0);
+				can_get_echo_skb(net, 0, NULL);
 				priv->tx_len = 0;
 			}
 			netif_wake_queue(net);
diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
index b75175d59104..54aa7c25c4de 100644
--- a/drivers/net/can/sun4i_can.c
+++ b/drivers/net/can/sun4i_can.c
@@ -655,7 +655,7 @@ static irqreturn_t sun4i_can_interrupt(int irq, void *dev_id)
 			    readl(priv->base +
 				  SUN4I_REG_RBUF_RBACK_START_ADDR) & 0xf;
 			stats->tx_packets++;
-			can_get_echo_skb(dev, 0);
+			can_get_echo_skb(dev, 0, NULL);
 			netif_wake_queue(dev);
 			can_led_event(dev, CAN_LED_EVENT_TX);
 		}
diff --git a/drivers/net/can/usb/ems_usb.c b/drivers/net/can/usb/ems_usb.c
index 5e5330060464..18f40eb20360 100644
--- a/drivers/net/can/usb/ems_usb.c
+++ b/drivers/net/can/usb/ems_usb.c
@@ -518,7 +518,7 @@ static void ems_usb_write_bulk_callback(struct urb *urb)
 	netdev->stats.tx_packets++;
 	netdev->stats.tx_bytes += context->dlc;
 
-	can_get_echo_skb(netdev, context->echo_index);
+	can_get_echo_skb(netdev, context->echo_index, NULL);
 
 	/* Release context */
 	context->echo_index = MAX_TX_URBS;
diff --git a/drivers/net/can/usb/esd_usb2.c b/drivers/net/can/usb/esd_usb2.c
index 68d8a85f00c4..562acbf454fd 100644
--- a/drivers/net/can/usb/esd_usb2.c
+++ b/drivers/net/can/usb/esd_usb2.c
@@ -357,7 +357,7 @@ static void esd_usb2_tx_done_msg(struct esd_usb2_net_priv *priv,
 	if (!msg->msg.txdone.status) {
 		stats->tx_packets++;
 		stats->tx_bytes += context->len;
-		can_get_echo_skb(netdev, context->echo_index);
+		can_get_echo_skb(netdev, context->echo_index, NULL);
 	} else {
 		stats->tx_errors++;
 		can_free_echo_skb(netdev, context->echo_index);
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 5ce9ba5d29d6..a00dc1904415 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -370,7 +370,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb)
 			goto resubmit_urb;
 		}
 
-		can_get_echo_skb(netdev, hf->echo_id);
+		can_get_echo_skb(netdev, hf->echo_id, NULL);
 
 		gs_free_tx_context(txc);
 
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
index 480bd2ecb296..dcee8dc828ec 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_hydra.c
@@ -1151,7 +1151,7 @@ static void kvaser_usb_hydra_tx_acknowledge(const struct kvaser_usb *dev,
 
 	spin_lock_irqsave(&priv->tx_contexts_lock, irq_flags);
 
-	can_get_echo_skb(priv->netdev, context->echo_index);
+	can_get_echo_skb(priv->netdev, context->echo_index, NULL);
 	context->echo_index = dev->max_tx_urbs;
 	--priv->active_tx_contexts;
 	netif_wake_queue(priv->netdev);
diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
index 98c016ef0607..59ba7c7beec0 100644
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_leaf.c
@@ -594,7 +594,7 @@ static void kvaser_usb_leaf_tx_acknowledge(const struct kvaser_usb *dev,
 
 	spin_lock_irqsave(&priv->tx_contexts_lock, flags);
 
-	can_get_echo_skb(priv->netdev, context->echo_index);
+	can_get_echo_skb(priv->netdev, context->echo_index, NULL);
 	context->echo_index = dev->max_tx_urbs;
 	--priv->active_tx_contexts;
 	netif_wake_queue(priv->netdev);
diff --git a/drivers/net/can/usb/mcba_usb.c b/drivers/net/can/usb/mcba_usb.c
index 5347c89992ce..4232a7126c1b 100644
--- a/drivers/net/can/usb/mcba_usb.c
+++ b/drivers/net/can/usb/mcba_usb.c
@@ -237,7 +237,7 @@ static void mcba_usb_write_bulk_callback(struct urb *urb)
 		netdev->stats.tx_bytes += ctx->dlc;
 
 		can_led_event(netdev, CAN_LED_EVENT_TX);
-		can_get_echo_skb(netdev, ctx->ndx);
+		can_get_echo_skb(netdev, ctx->ndx, NULL);
 	}
 
 	if (urb->status)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
index 95672750419a..573b11559d73 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c
@@ -309,7 +309,7 @@ static void peak_usb_write_bulk_callback(struct urb *urb)
 	}
 
 	/* should always release echo skb and corresponding context */
-	can_get_echo_skb(netdev, context->echo_index);
+	can_get_echo_skb(netdev, context->echo_index, NULL);
 	context->echo_index = PCAN_USB_MAX_TX_URBS;
 
 	/* do wakeup tx queue in case of success only */
diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index 5add27614e2b..fa403c080871 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -672,7 +672,7 @@ static void ucan_tx_complete_msg(struct ucan_priv *up,
 			/* update statistics */
 			up->netdev->stats.tx_packets++;
 			up->netdev->stats.tx_bytes += dlc;
-			can_get_echo_skb(up->netdev, echo_index);
+			can_get_echo_skb(up->netdev, echo_index, NULL);
 		} else {
 			up->netdev->stats.tx_dropped++;
 			can_free_echo_skb(up->netdev, echo_index);
diff --git a/drivers/net/can/usb/usb_8dev.c b/drivers/net/can/usb/usb_8dev.c
index 2e824d9d8167..e8c42430a4fc 100644
--- a/drivers/net/can/usb/usb_8dev.c
+++ b/drivers/net/can/usb/usb_8dev.c
@@ -585,7 +585,7 @@ static void usb_8dev_write_bulk_callback(struct urb *urb)
 	netdev->stats.tx_packets++;
 	netdev->stats.tx_bytes += context->dlc;
 
-	can_get_echo_skb(netdev, context->echo_index);
+	can_get_echo_skb(netdev, context->echo_index, NULL);
 
 	can_led_event(netdev, CAN_LED_EVENT_TX);
 
diff --git a/drivers/net/can/xilinx_can.c b/drivers/net/can/xilinx_can.c
index 8d5132a3f2c9..37fa19c62d73 100644
--- a/drivers/net/can/xilinx_can.c
+++ b/drivers/net/can/xilinx_can.c
@@ -1292,7 +1292,7 @@ static void xcan_tx_interrupt(struct net_device *ndev, u32 isr)
 
 	while (frames_sent--) {
 		stats->tx_bytes += can_get_echo_skb(ndev, priv->tx_tail %
-						    priv->tx_max);
+						    priv->tx_max, NULL);
 		priv->tx_tail++;
 		stats->tx_packets++;
 	}
diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h
index eaac4a637ae0..685f34cfba20 100644
--- a/include/linux/can/skb.h
+++ b/include/linux/can/skb.h
@@ -21,7 +21,8 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 		     unsigned int idx, unsigned int frame_len);
 struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx,
 				   u8 *len_ptr, unsigned int *frame_len_ptr);
-unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx);
+unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx,
+			      unsigned int *frame_len_ptr);
 void can_free_echo_skb(struct net_device *dev, unsigned int idx);
 struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf);
 struct sk_buff *alloc_canfd_skb(struct net_device *dev,
-- 
2.29.2

[net-next v2 14/15] can: dev: can_rx_offload_get_echo_skb(): extend to return can frame length

[Marc Kleine-Budde]

In order to implement byte queue limits (bql) in CAN drivers, the length of the
CAN frame needs to be passed into the networking stack after queueing and after
transmission completion.

To avoid to calculate this length twice, extend can_rx_offload_get_echo_skb()
to return that value. Convert all users of this function, too.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/rx-offload.c               | 5 +++--
 drivers/net/can/flexcan.c                      | 5 +++--
 drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 2 +-
 drivers/net/can/ti_hecc.c                      | 2 +-
 include/linux/can/rx-offload.h                 | 3 ++-
 5 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/net/can/dev/rx-offload.c b/drivers/net/can/dev/rx-offload.c
index 6a26b5282df1..ab2c1543786c 100644
--- a/drivers/net/can/dev/rx-offload.c
+++ b/drivers/net/can/dev/rx-offload.c
@@ -263,7 +263,8 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 EXPORT_SYMBOL_GPL(can_rx_offload_queue_sorted);
 
 unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
-					 unsigned int idx, u32 timestamp)
+					 unsigned int idx, u32 timestamp,
+					 unsigned int *frame_len_ptr)
 {
 	struct net_device *dev = offload->dev;
 	struct net_device_stats *stats = &dev->stats;
@@ -271,7 +272,7 @@ unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
 	u8 len;
 	int err;
 
-	skb = __can_get_echo_skb(dev, idx, &len, NULL);
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
 	if (!skb)
 		return 0;
 
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 202d08f8e1a4..5d9157c655e9 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1122,8 +1122,9 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 		u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
 
 		handled = IRQ_HANDLED;
-		stats->tx_bytes += can_rx_offload_get_echo_skb(&priv->offload,
-							       0, reg_ctrl << 16);
+		stats->tx_bytes +=
+			can_rx_offload_get_echo_skb(&priv->offload, 0,
+						    reg_ctrl << 16, NULL);
 		stats->tx_packets++;
 		can_led_event(dev, CAN_LED_EVENT_TX);
 
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 95bba456a4cd..63bbe0930e53 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -1271,7 +1271,7 @@ mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
 	stats->tx_bytes +=
 		can_rx_offload_get_echo_skb(&priv->offload,
 					    mcp251xfd_get_tef_tail(priv),
-					    hw_tef_obj->ts);
+					    hw_tef_obj->ts, NULL);
 	stats->tx_packets++;
 	priv->tef->tail++;
 
diff --git a/drivers/net/can/ti_hecc.c b/drivers/net/can/ti_hecc.c
index 485c19bc98c2..73245d8836a9 100644
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -757,7 +757,7 @@ static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id)
 			stamp = hecc_read_stamp(priv, mbxno);
 			stats->tx_bytes +=
 				can_rx_offload_get_echo_skb(&priv->offload,
-							    mbxno, stamp);
+							    mbxno, stamp, NULL);
 			stats->tx_packets++;
 			can_led_event(ndev, CAN_LED_EVENT_TX);
 			--priv->tx_tail;
diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h
index f1b38088b765..40882df7105e 100644
--- a/include/linux/can/rx-offload.h
+++ b/include/linux/can/rx-offload.h
@@ -44,7 +44,8 @@ int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload);
 int can_rx_offload_queue_sorted(struct can_rx_offload *offload,
 				struct sk_buff *skb, u32 timestamp);
 unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload,
-					 unsigned int idx, u32 timestamp);
+					 unsigned int idx, u32 timestamp,
+					 unsigned int *frame_len_ptr);
 int can_rx_offload_queue_tail(struct can_rx_offload *offload,
 			      struct sk_buff *skb);
 void can_rx_offload_del(struct can_rx_offload *offload);
-- 
2.29.2

[net-next v2 15/15] can: dev: add software tx timestamps

[Marc Kleine-Budde]

From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

Call skb_tx_timestamp() within can_put_echo_skb() so that a software
tx timestamp gets attached on the skb.

There two main reasons to include this call in can_put_echo_skb():

  * It easily allow to enable the tx timestamp on all devices with
    just one small change.

  * According to Documentation/networking/timestamping.rst, the tx
    timestamps should be generated in the device driver as close as
    possible, but always prior to passing the packet to the network
    interface. During the call to can_put_echo_skb(), the skb gets
    cloned meaning that the driver should not dereference the skb
    variable anymore after can_put_echo_skb() returns. This makes
    can_put_echo_skb() the very last place we can use the skb without
    having to access the echo_skb[] array.

Remarks:

  * By default, skb_tx_timestamp() does nothing. It needs to be
    activated by passing the SOF_TIMESTAMPING_TX_SOFTWARE flag either
    through socket options or control messages.

  * The hardware rx timestamp of a local loopback message is the
    hardware tx timestamp. This means that there are no needs to
    implement SOF_TIMESTAMPING_TX_HARDWARE for CAN sockets.

References:

Support for the error queue in CAN RAW sockets (which is needed for tx
timestamps) was introduced in:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb88531bdbfaafb827192d1fc6c5a3fcc4fadd96

Put the call to skb_tx_timestamp() just before adding it to the array:
https://lkml.org/lkml/2021/1/10/54

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/r/20210110124903.109773-2-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev/skb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index 53683d4312f1..f858f994cd49 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -61,6 +61,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
 		skb->pkt_type = PACKET_BROADCAST;
 		skb->ip_summed = CHECKSUM_UNNECESSARY;
 		skb->dev = dev;
+		skb_tx_timestamp(skb);
 
 		/* save frame_len to reuse it when transmission is completed */
 		can_skb_prv(skb)->frame_len = frame_len;
-- 
2.29.2

Re: [net-next v2 15/15] can: dev: add software tx timestamps

[Vincent MAILHOL]

On Mon. 11 Jan 2021 at 19:45, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
>
> From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
>
> Call skb_tx_timestamp() within can_put_echo_skb() so that a software
> tx timestamp gets attached on the skb.
>
> There two main reasons to include this call in can_put_echo_skb():
>
>   * It easily allow to enable the tx timestamp on all devices with
>     just one small change.
>
>   * According to Documentation/networking/timestamping.rst, the tx
>     timestamps should be generated in the device driver as close as
>     possible, but always prior to passing the packet to the network
>     interface. During the call to can_put_echo_skb(), the skb gets
>     cloned meaning that the driver should not dereference the skb
>     variable anymore after can_put_echo_skb() returns. This makes
>     can_put_echo_skb() the very last place we can use the skb without
>     having to access the echo_skb[] array.
>
> Remarks:
>
>   * By default, skb_tx_timestamp() does nothing. It needs to be
>     activated by passing the SOF_TIMESTAMPING_TX_SOFTWARE flag either
>     through socket options or control messages.
>
>   * The hardware rx timestamp of a local loopback message is the
>     hardware tx timestamp. This means that there are no needs to
>     implement SOF_TIMESTAMPING_TX_HARDWARE for CAN sockets.
>
> References:
>
> Support for the error queue in CAN RAW sockets (which is needed for tx
> timestamps) was introduced in:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eb88531bdbfaafb827192d1fc6c5a3fcc4fadd96
>
> Put the call to skb_tx_timestamp() just before adding it to the array:
> https://lkml.org/lkml/2021/1/10/54
>
> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
> Link: https://lore.kernel.org/r/20210110124903.109773-2-mailhol.vincent@wanadoo.fr
> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
> ---
>  drivers/net/can/dev/skb.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
> index 53683d4312f1..f858f994cd49 100644
> --- a/drivers/net/can/dev/skb.c
> +++ b/drivers/net/can/dev/skb.c
> @@ -61,6 +61,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev,
>                 skb->pkt_type = PACKET_BROADCAST;
>                 skb->ip_summed = CHECKSUM_UNNECESSARY;
>                 skb->dev = dev;
> +               skb_tx_timestamp(skb);
>
>                 /* save frame_len to reuse it when transmission is completed */
>                 can_skb_prv(skb)->frame_len = frame_len;
> --
> 2.29.2
>
>

A small detail, I would prefer to see the call to
skb_tx_timestamp() at the bottom just before we put the skb in
the array. The reason is that the later we do the timestamp, the
better it is.

        /* make settings for echo to reduce code in irq context */
        skb->pkt_type = PACKET_BROADCAST;
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->dev = dev;

        /* save frame_len to reuse it when transmission is completed */
        can_skb_prv(skb)->frame_len = frame_len;

+        skb_tx_timestamp(skb);

        /* save this skb for tx interrupt echo handling */
        priv->echo_skb[idx] = skb;

But it does not really matter.


Yours sincerely,
Vincent