Resguardo inicial

linux-7.2.3/drivers/net/can/dev/Makefile

@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_CAN_DEV) += can-dev.o
+
+can-dev-y += skb.o
+
+can-dev-$(CONFIG_CAN_CALC_BITTIMING) += calc_bittiming.o
+can-dev-$(CONFIG_CAN_NETLINK) += bittiming.o
+can-dev-$(CONFIG_CAN_NETLINK) += dev.o
+can-dev-$(CONFIG_CAN_NETLINK) += length.o
+can-dev-$(CONFIG_CAN_NETLINK) += netlink.o
+can-dev-$(CONFIG_CAN_RX_OFFLOAD) += rx-offload.o

linux-7.2.3/drivers/net/can/dev/bittiming.c

@@ -0,0 +1,216 @@
+// 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>
+ * Copyright (c) 2025 Vincent Mailhol <mailhol@kernel.org>
+ */
+
+#include <linux/can/dev.h>
+
+void can_sjw_set_default(struct can_bittiming *bt)
+{
+	if (bt->sjw)
+		return;
+
+	/* If user space provides no sjw, use sane default of phase_seg2 / 2 */
+	bt->sjw = max(1U, min(bt->phase_seg1, bt->phase_seg2 / 2));
+}
+
+int can_sjw_check(const struct net_device *dev, const struct can_bittiming *bt,
+		  const struct can_bittiming_const *btc, struct netlink_ext_ack *extack)
+{
+	if (bt->sjw > btc->sjw_max) {
+		NL_SET_ERR_MSG_FMT(extack, "sjw: %u greater than max sjw: %u",
+				   bt->sjw, btc->sjw_max);
+		return -EINVAL;
+	}
+
+	if (bt->sjw > bt->phase_seg1) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "sjw: %u greater than phase-seg1: %u",
+				   bt->sjw, bt->phase_seg1);
+		return -EINVAL;
+	}
+
+	if (bt->sjw > bt->phase_seg2) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "sjw: %u greater than phase-seg2: %u",
+				   bt->sjw, bt->phase_seg2);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* 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(const struct net_device *dev, struct can_bittiming *bt,
+			       const struct can_bittiming_const *btc,
+			       struct netlink_ext_ack *extack)
+{
+	const unsigned int tseg1 = bt->prop_seg + bt->phase_seg1;
+	const struct can_priv *priv = netdev_priv(dev);
+	u64 brp64;
+	int err;
+
+	if (tseg1 < btc->tseg1_min) {
+		NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u less than tseg1-min: %u",
+				   tseg1, btc->tseg1_min);
+		return -EINVAL;
+	}
+	if (tseg1 > btc->tseg1_max) {
+		NL_SET_ERR_MSG_FMT(extack, "prop-seg + phase-seg1: %u greater than tseg1-max: %u",
+				   tseg1, btc->tseg1_max);
+		return -EINVAL;
+	}
+	if (bt->phase_seg2 < btc->tseg2_min) {
+		NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u less than tseg2-min: %u",
+				   bt->phase_seg2, btc->tseg2_min);
+		return -EINVAL;
+	}
+	if (bt->phase_seg2 > btc->tseg2_max) {
+		NL_SET_ERR_MSG_FMT(extack, "phase-seg2: %u greater than tseg2-max: %u",
+				   bt->phase_seg2, btc->tseg2_max);
+		return -EINVAL;
+	}
+
+	can_sjw_set_default(bt);
+
+	err = can_sjw_check(dev, bt, btc, extack);
+	if (err)
+		return err;
+
+	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) {
+		NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u less than brp-min: %u",
+				   bt->brp, btc->brp_min);
+		return -EINVAL;
+	}
+	if (bt->brp > btc->brp_max) {
+		NL_SET_ERR_MSG_FMT(extack, "resulting brp: %u greater than brp-max: %u",
+				   bt->brp, btc->brp_max);
+		return -EINVAL;
+	}
+
+	bt->bitrate = priv->clock.freq / (bt->brp * can_bit_time(bt));
+	bt->sample_point = ((CAN_SYNC_SEG + tseg1) * 1000) / can_bit_time(bt);
+	bt->tq = DIV_U64_ROUND_CLOSEST(mul_u32_u32(bt->brp, NSEC_PER_SEC),
+				       priv->clock.freq);
+
+	return 0;
+}
+
+/* Checks the validity of predefined bitrate settings */
+static int
+can_validate_bitrate(const struct net_device *dev, const struct can_bittiming *bt,
+		     const u32 *bitrate_const,
+		     const unsigned int bitrate_const_cnt,
+		     struct netlink_ext_ack *extack)
+{
+	unsigned int i;
+
+	for (i = 0; i < bitrate_const_cnt; i++) {
+		if (bt->bitrate == bitrate_const[i])
+			return 0;
+	}
+
+	NL_SET_ERR_MSG_FMT(extack, "bitrate %u bps not supported",
+			   bt->brp);
+
+	return -EINVAL;
+}
+
+int can_get_bittiming(const struct net_device *dev, struct can_bittiming *bt,
+		      const struct can_bittiming_const *btc,
+		      const u32 *bitrate_const,
+		      const unsigned int bitrate_const_cnt,
+		      struct netlink_ext_ack *extack)
+{
+	/* Depending on the given can_bittiming parameter structure the CAN
+	 * timing parameters are calculated based on the provided bitrate OR
+	 * alternatively the CAN timing parameters (tq, prop_seg, etc.) are
+	 * provided directly which are then checked and fixed up.
+	 */
+	if (!bt->tq && bt->bitrate && btc)
+		return can_calc_bittiming(dev, bt, btc, extack);
+	if (bt->tq && !bt->bitrate && btc)
+		return can_fixup_bittiming(dev, bt, btc, extack);
+	if (!bt->tq && bt->bitrate && bitrate_const)
+		return can_validate_bitrate(dev, bt, bitrate_const,
+					    bitrate_const_cnt, extack);
+
+	return -EINVAL;
+}
+
+int can_validate_pwm_bittiming(const struct net_device *dev,
+			       const struct can_pwm *pwm,
+			       struct netlink_ext_ack *extack)
+{
+	const struct can_priv *priv = netdev_priv(dev);
+	u32 xl_bit_time_tqmin = can_bit_time_tqmin(&priv->xl.data_bittiming);
+	u32 nom_bit_time_tqmin = can_bit_time_tqmin(&priv->bittiming);
+	u32 pwms_ns = can_tqmin_to_ns(pwm->pwms, priv->clock.freq);
+	u32 pwml_ns = can_tqmin_to_ns(pwm->pwml, priv->clock.freq);
+
+	if (pwms_ns + pwml_ns > CAN_PWM_NS_MAX) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "The PWM symbol duration: %u ns may not exceed %u ns",
+				   pwms_ns + pwml_ns, CAN_PWM_NS_MAX);
+		return -EINVAL;
+	}
+
+	if (pwms_ns < CAN_PWM_DECODE_NS) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "PWMS: %u ns shall be at least %u ns",
+				   pwms_ns, CAN_PWM_DECODE_NS);
+		return -EINVAL;
+	}
+
+	if (pwm->pwms >= pwm->pwml) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "PWMS: %u tqmin shall be smaller than PWML: %u tqmin",
+				   pwm->pwms, pwm->pwml);
+		return -EINVAL;
+	}
+
+	if (pwml_ns - pwms_ns < 2 * CAN_PWM_DECODE_NS) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "At least %u ns shall separate PWMS: %u ns from PMWL: %u ns",
+				   2 * CAN_PWM_DECODE_NS, pwms_ns, pwml_ns);
+		return -EINVAL;
+	}
+
+	if (xl_bit_time_tqmin % (pwm->pwms + pwm->pwml) != 0) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "PWM duration: %u tqmin does not divide XL's bit time: %u tqmin",
+				   pwm->pwms + pwm->pwml, xl_bit_time_tqmin);
+		return -EINVAL;
+	}
+
+	if (pwm->pwmo >= pwm->pwms + pwm->pwml) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "PWMO: %u tqmin can not be greater than PWMS + PWML: %u tqmin",
+				   pwm->pwmo, pwm->pwms + pwm->pwml);
+		return -EINVAL;
+	}
+
+	if (nom_bit_time_tqmin % (pwm->pwms + pwm->pwml) != pwm->pwmo) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "Can not assemble nominal bit time: %u tqmin out of PWMS + PMWL and PWMO",
+				   nom_bit_time_tqmin);
+		return -EINVAL;
+	}
+
+	return 0;
+}

linux-7.2.3/drivers/net/can/dev/calc_bittiming.c

@@ -0,0 +1,262 @@
+// 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>
+ * Copyright (C) 2021-2025 Vincent Mailhol <mailhol@kernel.org>
+ */
+
+#include <linux/units.h>
+#include <linux/can/dev.h>
+
+#define CAN_CALC_MAX_ERROR 500 /* max error 5% */
+
+/* CiA recommended sample points for Non Return to Zero encoding. */
+static int can_calc_sample_point_nrz(const struct can_bittiming *bt)
+{
+	if (bt->bitrate > 800 * KILO /* BPS */)
+		return 750;
+
+	if (bt->bitrate > 500 * KILO /* BPS */)
+		return 800;
+
+	return 875;
+}
+
+/* Sample points for Pulse-Width Modulation encoding. */
+static int can_calc_sample_point_pwm(const struct can_bittiming *bt)
+{
+	if (bt->bitrate > 15 * MEGA /* BPS */)
+		return 625;
+
+	if (bt->bitrate > 9 * MEGA /* BPS */)
+		return 600;
+
+	if (bt->bitrate > 4 * MEGA /* BPS */)
+		return 560;
+
+	return 520;
+}
+
+/* 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,
+			const unsigned int sample_point_reference, const 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_reference * (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_reference - sample_point);
+
+		if (sample_point <= sample_point_reference &&
+		    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(const struct net_device *dev, struct can_bittiming *bt,
+		       const struct can_bittiming_const *btc, struct netlink_ext_ack *extack)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	unsigned int bitrate;			/* current bitrate */
+	unsigned int bitrate_error;		/* diff between calculated and reference value */
+	unsigned int best_bitrate_error = UINT_MAX;
+	unsigned int sample_point_error;	/* diff between calculated and reference value */
+	unsigned int best_sample_point_error = UINT_MAX;
+	unsigned int sample_point_reference;	/* reference 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;
+	int err;
+
+	if (bt->sample_point)
+		sample_point_reference = bt->sample_point;
+	else if (btc == priv->xl.data_bittiming_const &&
+		 (priv->ctrlmode & CAN_CTRLMODE_XL_TMS))
+		sample_point_reference = can_calc_sample_point_pwm(bt);
+	else
+		sample_point_reference = can_calc_sample_point_nrz(bt);
+
+	/* 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_reference, 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-hundredth of a percent */
+		v64 = (u64)best_bitrate_error * 10000;
+		do_div(v64, bt->bitrate);
+		bitrate_error = (u32)v64;
+		/* print at least 0.01% if the error is smaller */
+		bitrate_error = max(bitrate_error, 1U);
+		if (bitrate_error > CAN_CALC_MAX_ERROR) {
+			NL_SET_ERR_MSG_FMT(extack,
+					   "bitrate error: %u.%02u%% too high",
+					   bitrate_error / 100,
+					   bitrate_error % 100);
+			return -EINVAL;
+		}
+		NL_SET_ERR_MSG_FMT(extack,
+				   "bitrate error: %u.%02u%%",
+				   bitrate_error / 100, bitrate_error % 100);
+	}
+
+	/* real sample point */
+	bt->sample_point = can_update_sample_point(btc, sample_point_reference,
+						   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;
+
+	can_sjw_set_default(bt);
+
+	err = can_sjw_check(dev, bt, btc, extack);
+	if (err)
+		return err;
+
+	bt->brp = best_brp;
+
+	/* real bitrate */
+	bt->bitrate = priv->clock.freq /
+		(bt->brp * can_bit_time(bt));
+
+	return 0;
+}
+
+void can_calc_tdco(struct can_tdc *tdc, const struct can_tdc_const *tdc_const,
+		   const struct can_bittiming *dbt,
+		   u32 tdc_mask, u32 *ctrlmode, u32 ctrlmode_supported)
+
+{
+	u32 tdc_auto = tdc_mask & CAN_CTRLMODE_TDC_AUTO_MASK;
+
+	if (!tdc_const || !(ctrlmode_supported & tdc_auto))
+		return;
+
+	*ctrlmode &= ~tdc_mask;
+
+	/* As specified in ISO 11898-1 section 11.3.3 "Transmitter
+	 * delay compensation" (TDC) is only applicable if data BRP is
+	 * one or two.
+	 */
+	if (dbt->brp == 1 || dbt->brp == 2) {
+		/* Sample point in clock periods */
+		u32 sample_point_in_tc = (CAN_SYNC_SEG + dbt->prop_seg +
+					  dbt->phase_seg1) * dbt->brp;
+
+		if (sample_point_in_tc < tdc_const->tdco_min)
+			return;
+		tdc->tdco = min(sample_point_in_tc, tdc_const->tdco_max);
+		*ctrlmode |= tdc_auto;
+	}
+}
+
+int can_calc_pwm(struct net_device *dev, struct netlink_ext_ack *extack)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	const struct can_pwm_const *pwm_const = priv->xl.pwm_const;
+	struct can_pwm *pwm = &priv->xl.pwm;
+	u32 xl_tqmin = can_bit_time_tqmin(&priv->xl.data_bittiming);
+	u32 xl_ns = can_tqmin_to_ns(xl_tqmin, priv->clock.freq);
+	u32 nom_tqmin = can_bit_time_tqmin(&priv->bittiming);
+	int pwm_per_bit_max = xl_tqmin / (pwm_const->pwms_min + pwm_const->pwml_min);
+	int pwm_per_bit;
+	u32 pwm_tqmin;
+
+	/* For 5 MB/s databitrate or greater, xl_ns < CAN_PWM_NS_MAX
+	 * giving us a pwm_per_bit of 1 and the loop immediately breaks
+	 */
+	for (pwm_per_bit = DIV_ROUND_UP(xl_ns, CAN_PWM_NS_MAX);
+	     pwm_per_bit <= pwm_per_bit_max; pwm_per_bit++)
+		if (xl_tqmin % pwm_per_bit == 0)
+			break;
+
+	if (pwm_per_bit > pwm_per_bit_max) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "Can not divide the XL data phase's bit time: %u tqmin into multiple PWM symbols",
+				   xl_tqmin);
+		return -EINVAL;
+	}
+
+	pwm_tqmin = xl_tqmin / pwm_per_bit;
+	pwm->pwms = DIV_ROUND_UP_POW2(pwm_tqmin, 4);
+	pwm->pwml = pwm_tqmin - pwm->pwms;
+	pwm->pwmo = nom_tqmin % pwm_tqmin;
+
+	return 0;
+}

linux-7.2.3/drivers/net/can/dev/dev.c

@@ -0,0 +1,689 @@
+// 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.h>
+#include <linux/can/can-ml.h>
+#include <linux/can/dev.h>
+#include <linux/can/skb.h>
+#include <linux/gpio/consumer.h>
+#include <linux/if_arp.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+static void can_update_state_error_stats(struct net_device *dev,
+					 enum can_state new_state)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (new_state <= priv->state)
+		return;
+
+	switch (new_state) {
+	case CAN_STATE_ERROR_WARNING:
+		priv->can_stats.error_warning++;
+		break;
+	case CAN_STATE_ERROR_PASSIVE:
+		priv->can_stats.error_passive++;
+		break;
+	case CAN_STATE_BUS_OFF:
+		priv->can_stats.bus_off++;
+		break;
+	default:
+		break;
+	}
+}
+
+static int can_tx_state_to_frame(struct net_device *dev, enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return CAN_ERR_CRTL_ACTIVE;
+	case CAN_STATE_ERROR_WARNING:
+		return CAN_ERR_CRTL_TX_WARNING;
+	case CAN_STATE_ERROR_PASSIVE:
+		return CAN_ERR_CRTL_TX_PASSIVE;
+	default:
+		return 0;
+	}
+}
+
+static int can_rx_state_to_frame(struct net_device *dev, enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return CAN_ERR_CRTL_ACTIVE;
+	case CAN_STATE_ERROR_WARNING:
+		return CAN_ERR_CRTL_RX_WARNING;
+	case CAN_STATE_ERROR_PASSIVE:
+		return CAN_ERR_CRTL_RX_PASSIVE;
+	default:
+		return 0;
+	}
+}
+
+const char *can_get_state_str(const enum can_state state)
+{
+	switch (state) {
+	case CAN_STATE_ERROR_ACTIVE:
+		return "Error Active";
+	case CAN_STATE_ERROR_WARNING:
+		return "Error Warning";
+	case CAN_STATE_ERROR_PASSIVE:
+		return "Error Passive";
+	case CAN_STATE_BUS_OFF:
+		return "Bus Off";
+	case CAN_STATE_STOPPED:
+		return "Stopped";
+	case CAN_STATE_SLEEPING:
+		return "Sleeping";
+	default:
+		return "<unknown>";
+	}
+}
+EXPORT_SYMBOL_GPL(can_get_state_str);
+
+const char *can_get_ctrlmode_str(u32 ctrlmode)
+{
+	switch (ctrlmode & ~(ctrlmode - 1)) {
+	case 0:
+		return "(none)";
+	case CAN_CTRLMODE_LOOPBACK:
+		return "LOOPBACK";
+	case CAN_CTRLMODE_LISTENONLY:
+		return "LISTEN-ONLY";
+	case CAN_CTRLMODE_3_SAMPLES:
+		return "TRIPLE-SAMPLING";
+	case CAN_CTRLMODE_ONE_SHOT:
+		return "ONE-SHOT";
+	case CAN_CTRLMODE_BERR_REPORTING:
+		return "BERR-REPORTING";
+	case CAN_CTRLMODE_FD:
+		return "FD";
+	case CAN_CTRLMODE_PRESUME_ACK:
+		return "PRESUME-ACK";
+	case CAN_CTRLMODE_FD_NON_ISO:
+		return "FD-NON-ISO";
+	case CAN_CTRLMODE_CC_LEN8_DLC:
+		return "CC-LEN8-DLC";
+	case CAN_CTRLMODE_TDC_AUTO:
+		return "TDC-AUTO";
+	case CAN_CTRLMODE_TDC_MANUAL:
+		return "TDC-MANUAL";
+	case CAN_CTRLMODE_RESTRICTED:
+		return "RESTRICTED";
+	case CAN_CTRLMODE_XL:
+		return "XL";
+	case CAN_CTRLMODE_XL_TDC_AUTO:
+		return "XL-TDC-AUTO";
+	case CAN_CTRLMODE_XL_TDC_MANUAL:
+		return "XL-TDC-MANUAL";
+	case CAN_CTRLMODE_XL_TMS:
+		return "TMS";
+	default:
+		return "<unknown>";
+	}
+}
+EXPORT_SYMBOL_GPL(can_get_ctrlmode_str);
+
+static enum can_state can_state_err_to_state(u16 err)
+{
+	if (err < CAN_ERROR_WARNING_THRESHOLD)
+		return CAN_STATE_ERROR_ACTIVE;
+	if (err < CAN_ERROR_PASSIVE_THRESHOLD)
+		return CAN_STATE_ERROR_WARNING;
+	if (err < CAN_BUS_OFF_THRESHOLD)
+		return CAN_STATE_ERROR_PASSIVE;
+
+	return CAN_STATE_BUS_OFF;
+}
+
+void can_state_get_by_berr_counter(const struct net_device *dev,
+				   const struct can_berr_counter *bec,
+				   enum can_state *tx_state,
+				   enum can_state *rx_state)
+{
+	*tx_state = can_state_err_to_state(bec->txerr);
+	*rx_state = can_state_err_to_state(bec->rxerr);
+}
+EXPORT_SYMBOL_GPL(can_state_get_by_berr_counter);
+
+void can_change_state(struct net_device *dev, struct can_frame *cf,
+		      enum can_state tx_state, enum can_state rx_state)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	enum can_state new_state = max(tx_state, rx_state);
+
+	if (unlikely(new_state == priv->state)) {
+		netdev_warn(dev, "%s: oops, state did not change", __func__);
+		return;
+	}
+
+	netdev_dbg(dev, "Controller changed from %s State (%d) into %s State (%d).\n",
+		   can_get_state_str(priv->state), priv->state,
+		   can_get_state_str(new_state), new_state);
+
+	can_update_state_error_stats(dev, new_state);
+	priv->state = new_state;
+
+	if (!cf)
+		return;
+
+	if (unlikely(new_state == CAN_STATE_BUS_OFF)) {
+		cf->can_id |= CAN_ERR_BUSOFF;
+		return;
+	}
+
+	cf->can_id |= CAN_ERR_CRTL;
+	cf->data[1] |= tx_state >= rx_state ?
+		       can_tx_state_to_frame(dev, tx_state) : 0;
+	cf->data[1] |= tx_state <= rx_state ?
+		       can_rx_state_to_frame(dev, rx_state) : 0;
+}
+EXPORT_SYMBOL_GPL(can_change_state);
+
+/* CAN device restart for bus-off recovery */
+static int can_restart(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct sk_buff *skb;
+	struct can_frame *cf;
+	int err;
+
+	if (!priv->do_set_mode)
+		return -EOPNOTSUPP;
+
+	if (netif_carrier_ok(dev))
+		netdev_err(dev, "Attempt to restart for bus-off recovery, but carrier is OK?\n");
+
+	/* No synchronization needed because the device is bus-off and
+	 * no messages can come in or go out.
+	 */
+	can_flush_echo_skb(dev);
+
+	/* send restart message upstream */
+	skb = alloc_can_err_skb(dev, &cf);
+	if (skb) {
+		cf->can_id |= CAN_ERR_RESTARTED;
+		netif_rx(skb);
+	}
+
+	/* Now restart the device */
+	netif_carrier_on(dev);
+	err = priv->do_set_mode(dev, CAN_MODE_START);
+	if (err) {
+		netdev_err(dev, "Restart failed, error %pe\n", ERR_PTR(err));
+		netif_carrier_off(dev);
+
+		return err;
+	} else {
+		netdev_dbg(dev, "Restarted\n");
+		priv->can_stats.restarts++;
+	}
+
+	return 0;
+}
+
+static void can_restart_work(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct can_priv *priv = container_of(dwork, struct can_priv,
+					     restart_work);
+
+	can_restart(priv->dev);
+}
+
+int can_restart_now(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	/* A manual restart is only permitted if automatic restart is
+	 * disabled and the device is in the bus-off state
+	 */
+	if (priv->restart_ms)
+		return -EINVAL;
+	if (priv->state != CAN_STATE_BUS_OFF)
+		return -EBUSY;
+
+	cancel_delayed_work_sync(&priv->restart_work);
+
+	return can_restart(dev);
+}
+
+/* CAN bus-off
+ *
+ * This functions should be called when the device goes bus-off to
+ * tell the netif layer that no more packets can be sent or received.
+ * If enabled, a timer is started to trigger bus-off recovery.
+ */
+void can_bus_off(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (priv->restart_ms)
+		netdev_info(dev, "bus-off, scheduling restart in %d ms\n",
+			    priv->restart_ms);
+	else
+		netdev_info(dev, "bus-off\n");
+
+	netif_carrier_off(dev);
+
+	if (priv->restart_ms)
+		schedule_delayed_work(&priv->restart_work,
+				      msecs_to_jiffies(priv->restart_ms));
+}
+EXPORT_SYMBOL_GPL(can_bus_off);
+
+void can_setup(struct net_device *dev)
+{
+	dev->type = ARPHRD_CAN;
+	dev->mtu = CAN_MTU;
+	dev->min_mtu = CAN_MTU;
+	dev->max_mtu = CAN_MTU;
+	dev->hard_header_len = 0;
+	dev->addr_len = 0;
+	dev->tx_queue_len = 10;
+
+	/* New-style flags. */
+	dev->flags = IFF_NOARP;
+	dev->features = NETIF_F_HW_CSUM;
+}
+
+/* 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)
+{
+	struct can_ml_priv *can_ml;
+	struct net_device *dev;
+	struct can_priv *priv;
+	int size;
+
+	/* We put the driver's priv, the CAN mid layer priv and the
+	 * echo skb into the netdevice's priv. The memory layout for
+	 * the netdev_priv is like this:
+	 *
+	 * +-------------------------+
+	 * | driver's priv           |
+	 * +-------------------------+
+	 * | struct can_ml_priv      |
+	 * +-------------------------+
+	 * | array of struct sk_buff |
+	 * +-------------------------+
+	 */
+
+	size = ALIGN(sizeof_priv, NETDEV_ALIGN) + sizeof(struct can_ml_priv);
+
+	if (echo_skb_max)
+		size = ALIGN(size, sizeof(struct sk_buff *)) +
+			echo_skb_max * sizeof(struct sk_buff *);
+
+	dev = alloc_netdev_mqs(size, "can%d", NET_NAME_UNKNOWN, can_setup,
+			       txqs, rxqs);
+	if (!dev)
+		return NULL;
+
+	priv = netdev_priv(dev);
+	priv->dev = dev;
+
+	can_ml = (void *)priv + ALIGN(sizeof_priv, NETDEV_ALIGN);
+	can_set_ml_priv(dev, can_ml);
+	can_set_cap(dev, CAN_CAP_CC);
+
+	if (echo_skb_max) {
+		priv->echo_skb_max = echo_skb_max;
+		priv->echo_skb = (void *)priv +
+			(size - echo_skb_max * sizeof(struct sk_buff *));
+	}
+
+	priv->state = CAN_STATE_STOPPED;
+
+	INIT_DELAYED_WORK(&priv->restart_work, can_restart_work);
+
+	return dev;
+}
+EXPORT_SYMBOL_GPL(alloc_candev_mqs);
+
+/* Free space of the CAN network device */
+void free_candev(struct net_device *dev)
+{
+	free_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(free_candev);
+
+void can_set_default_mtu(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (priv->ctrlmode & CAN_CTRLMODE_XL) {
+		if (can_is_canxl_dev_mtu(dev->mtu))
+			return;
+		dev->mtu = CANXL_MTU;
+		dev->min_mtu = CANXL_MIN_MTU;
+		dev->max_mtu = CANXL_MAX_MTU;
+	} else if (priv->ctrlmode & CAN_CTRLMODE_FD) {
+		dev->mtu = CANFD_MTU;
+		dev->min_mtu = CANFD_MTU;
+		dev->max_mtu = CANFD_MTU;
+	} else {
+		dev->mtu = CAN_MTU;
+		dev->min_mtu = CAN_MTU;
+		dev->max_mtu = CAN_MTU;
+	}
+}
+
+void can_set_cap_info(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	u32 can_cap;
+
+	if (can_dev_in_xl_only_mode(priv)) {
+		/* XL only mode => no CC/FD capability */
+		can_cap = CAN_CAP_XL;
+	} else {
+		/* mixed mode => CC + FD/XL capability */
+		can_cap = CAN_CAP_CC;
+
+		if (priv->ctrlmode & CAN_CTRLMODE_FD)
+			can_cap |= CAN_CAP_FD;
+
+		if (priv->ctrlmode & CAN_CTRLMODE_XL)
+			can_cap |= CAN_CAP_XL;
+	}
+
+	if (priv->ctrlmode & (CAN_CTRLMODE_LISTENONLY |
+			      CAN_CTRLMODE_RESTRICTED))
+		can_cap |= CAN_CAP_RO;
+
+	can_set_cap(dev, can_cap);
+}
+
+/* helper to define static CAN controller features at device creation time */
+int can_set_static_ctrlmode(struct net_device *dev, u32 static_mode)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	/* alloc_candev() succeeded => netdev_priv() is valid at this point */
+	if (priv->ctrlmode_supported & static_mode) {
+		netdev_warn(dev,
+			    "Controller features can not be supported and static at the same time\n");
+		return -EINVAL;
+	}
+	priv->ctrlmode = static_mode;
+
+	/* override MTU which was set by default in can_setup()? */
+	can_set_default_mtu(dev);
+	can_set_cap_info(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_set_static_ctrlmode);
+
+/* generic implementation of netdev_ops::ndo_hwtstamp_get for CAN devices
+ * supporting hardware timestamps
+ */
+int can_hwtstamp_get(struct net_device *netdev,
+		     struct kernel_hwtstamp_config *cfg)
+{
+	cfg->tx_type = HWTSTAMP_TX_ON;
+	cfg->rx_filter = HWTSTAMP_FILTER_ALL;
+
+	return 0;
+}
+EXPORT_SYMBOL(can_hwtstamp_get);
+
+/* generic implementation of netdev_ops::ndo_hwtstamp_set for CAN devices
+ * supporting hardware timestamps
+ */
+int can_hwtstamp_set(struct net_device *netdev,
+		     struct kernel_hwtstamp_config *cfg,
+		     struct netlink_ext_ack *extack)
+{
+	if (cfg->tx_type == HWTSTAMP_TX_ON &&
+	    cfg->rx_filter == HWTSTAMP_FILTER_ALL)
+		return 0;
+	NL_SET_ERR_MSG_MOD(extack, "Only TX on and RX all packets filter supported");
+	return -ERANGE;
+}
+EXPORT_SYMBOL(can_hwtstamp_set);
+
+/* generic implementation of ethtool_ops::get_ts_info for CAN devices
+ * supporting hardware timestamps
+ */
+int can_ethtool_op_get_ts_info_hwts(struct net_device *dev,
+				    struct kernel_ethtool_ts_info *info)
+{
+	info->so_timestamping =
+		SOF_TIMESTAMPING_TX_SOFTWARE |
+		SOF_TIMESTAMPING_TX_HARDWARE |
+		SOF_TIMESTAMPING_RX_HARDWARE |
+		SOF_TIMESTAMPING_RAW_HARDWARE;
+	info->tx_types = BIT(HWTSTAMP_TX_ON);
+	info->rx_filters = BIT(HWTSTAMP_FILTER_ALL);
+
+	return 0;
+}
+EXPORT_SYMBOL(can_ethtool_op_get_ts_info_hwts);
+
+/* Common open function when the device gets opened.
+ *
+ * This function should be called in the open function of the device
+ * driver.
+ */
+int open_candev(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	if (!priv->bittiming.bitrate) {
+		netdev_err(dev, "bit-timing not yet defined\n");
+		return -EINVAL;
+	}
+
+	/* For CAN FD the data bitrate has to be >= the arbitration bitrate */
+	if ((priv->ctrlmode & CAN_CTRLMODE_FD) &&
+	    (!priv->fd.data_bittiming.bitrate ||
+	     priv->fd.data_bittiming.bitrate < priv->bittiming.bitrate)) {
+		netdev_err(dev, "incorrect/missing data bit-timing\n");
+		return -EINVAL;
+	}
+
+	/* Switch carrier on if device was stopped while in bus-off state */
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(open_candev);
+
+#ifdef CONFIG_OF
+/* Common function that can be used to understand the limitation of
+ * a transceiver when it provides no means to determine these limitations
+ * at runtime.
+ */
+void of_can_transceiver(struct net_device *dev)
+{
+	struct device_node *dn;
+	struct can_priv *priv = netdev_priv(dev);
+	struct device_node *np = dev->dev.parent->of_node;
+	int ret;
+
+	dn = of_get_child_by_name(np, "can-transceiver");
+	if (!dn)
+		return;
+
+	ret = of_property_read_u32(dn, "max-bitrate", &priv->bitrate_max);
+	of_node_put(dn);
+	if ((ret && ret != -EINVAL) || (!ret && !priv->bitrate_max))
+		netdev_warn(dev, "Invalid value for transceiver max bitrate. Ignoring bitrate limit.\n");
+}
+EXPORT_SYMBOL_GPL(of_can_transceiver);
+#endif
+
+/* Common close function for cleanup before the device gets closed.
+ *
+ * This function should be called in the close function of the device
+ * driver.
+ */
+void close_candev(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+
+	cancel_delayed_work_sync(&priv->restart_work);
+	can_flush_echo_skb(dev);
+}
+EXPORT_SYMBOL_GPL(close_candev);
+
+static int can_set_termination(struct net_device *ndev, u16 term)
+{
+	struct can_priv *priv = netdev_priv(ndev);
+	int set;
+
+	if (term == priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED])
+		set = 1;
+	else
+		set = 0;
+
+	gpiod_set_value_cansleep(priv->termination_gpio, set);
+
+	return 0;
+}
+
+static int can_get_termination(struct net_device *ndev)
+{
+	struct can_priv *priv = netdev_priv(ndev);
+	struct device *dev = ndev->dev.parent;
+	struct gpio_desc *gpio;
+	u32 term;
+	int ret;
+
+	/* Disabling termination by default is the safe choice: Else if many
+	 * bus participants enable it, no communication is possible at all.
+	 */
+	gpio = devm_gpiod_get_optional(dev, "termination", GPIOD_OUT_LOW);
+	if (IS_ERR(gpio))
+		return dev_err_probe(dev, PTR_ERR(gpio),
+				     "Cannot get termination-gpios\n");
+
+	if (!gpio)
+		return 0;
+
+	ret = device_property_read_u32(dev, "termination-ohms", &term);
+	if (ret) {
+		netdev_err(ndev, "Cannot get termination-ohms: %pe\n",
+			   ERR_PTR(ret));
+		return ret;
+	}
+
+	if (term > U16_MAX) {
+		netdev_err(ndev, "Invalid termination-ohms value (%u > %u)\n",
+			   term, U16_MAX);
+		return -EINVAL;
+	}
+
+	priv->termination_const_cnt = ARRAY_SIZE(priv->termination_gpio_ohms);
+	priv->termination_const = priv->termination_gpio_ohms;
+	priv->termination_gpio = gpio;
+	priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_DISABLED] =
+		CAN_TERMINATION_DISABLED;
+	priv->termination_gpio_ohms[CAN_TERMINATION_GPIO_ENABLED] = term;
+	priv->do_set_termination = can_set_termination;
+
+	return 0;
+}
+
+static bool
+can_bittiming_const_valid(const struct can_bittiming_const *btc)
+{
+	if (!btc)
+		return true;
+
+	if (!btc->sjw_max)
+		return false;
+
+	return true;
+}
+
+/* Register the CAN network device */
+int register_candev(struct net_device *dev)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	int err;
+
+	/* Ensure termination_const, termination_const_cnt and
+	 * do_set_termination consistency. All must be either set or
+	 * unset.
+	 */
+	if ((!priv->termination_const != !priv->termination_const_cnt) ||
+	    (!priv->termination_const != !priv->do_set_termination))
+		return -EINVAL;
+
+	if (!priv->bitrate_const != !priv->bitrate_const_cnt)
+		return -EINVAL;
+
+	if (!priv->fd.data_bitrate_const != !priv->fd.data_bitrate_const_cnt)
+		return -EINVAL;
+
+	/* We only support either fixed bit rates or bit timing const. */
+	if ((priv->bitrate_const || priv->fd.data_bitrate_const) &&
+	    (priv->bittiming_const || priv->fd.data_bittiming_const))
+		return -EINVAL;
+
+	if (!can_bittiming_const_valid(priv->bittiming_const) ||
+	    !can_bittiming_const_valid(priv->fd.data_bittiming_const))
+		return -EINVAL;
+
+	if (!priv->termination_const) {
+		err = can_get_termination(dev);
+		if (err)
+			return err;
+	}
+
+	dev->rtnl_link_ops = &can_link_ops;
+	netif_carrier_off(dev);
+
+	return register_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(register_candev);
+
+/* Unregister the CAN network device */
+void unregister_candev(struct net_device *dev)
+{
+	unregister_netdev(dev);
+}
+EXPORT_SYMBOL_GPL(unregister_candev);
+
+/* Test if a network device is a candev based device
+ * and return the can_priv* if so.
+ */
+struct can_priv *safe_candev_priv(struct net_device *dev)
+{
+	if (dev->type != ARPHRD_CAN || dev->rtnl_link_ops != &can_link_ops)
+		return NULL;
+
+	return netdev_priv(dev);
+}
+EXPORT_SYMBOL_GPL(safe_candev_priv);
+
+static __init int can_dev_init(void)
+{
+	int err;
+
+	err = can_netlink_register();
+	if (!err)
+		pr_info("CAN device driver interface\n");
+
+	return err;
+}
+module_init(can_dev_init);
+
+static __exit void can_dev_exit(void)
+{
+	can_netlink_unregister();
+}
+module_exit(can_dev_exit);
+
+MODULE_ALIAS_RTNL_LINK("can");

linux-7.2.3/drivers/net/can/dev/length.c

@@ -0,0 +1,84 @@
+// 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)
+{
+	/* check for length mapping table size at build time */
+	BUILD_BUG_ON(ARRAY_SIZE(len2dlc) != CANFD_MAX_DLEN + 1);
+
+	if (unlikely(len > CANFD_MAX_DLEN))
+		return CANFD_MAX_DLC;
+
+	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;
+
+	return can_frame_bytes(can_is_canfd_skb(skb), cf->can_id & CAN_EFF_FLAG,
+			       false, len);
+}
+EXPORT_SYMBOL_GPL(can_skb_get_frame_len);

linux-7.2.3/drivers/net/can/dev/rx-offload.c

@@ -0,0 +1,427 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2014      Protonic Holland,
+ *                         David Jander
+ * Copyright (C) 2014-2021, 2023 Pengutronix,
+ *                         Marc Kleine-Budde <kernel@pengutronix.de>
+ */
+
+#include <linux/can/dev.h>
+#include <linux/can/rx-offload.h>
+
+struct can_rx_offload_cb {
+	u32 timestamp;
+};
+
+static inline struct can_rx_offload_cb *
+can_rx_offload_get_cb(struct sk_buff *skb)
+{
+	BUILD_BUG_ON(sizeof(struct can_rx_offload_cb) > sizeof(skb->cb));
+
+	return (struct can_rx_offload_cb *)skb->cb;
+}
+
+static inline bool
+can_rx_offload_le(struct can_rx_offload *offload,
+		  unsigned int a, unsigned int b)
+{
+	if (offload->inc)
+		return a <= b;
+	else
+		return a >= b;
+}
+
+static inline unsigned int
+can_rx_offload_inc(struct can_rx_offload *offload, unsigned int *val)
+{
+	if (offload->inc)
+		return (*val)++;
+	else
+		return (*val)--;
+}
+
+static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota)
+{
+	struct can_rx_offload *offload = container_of(napi,
+						      struct can_rx_offload,
+						      napi);
+	struct net_device *dev = offload->dev;
+	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *skb;
+	int work_done = 0;
+
+	while ((work_done < quota) &&
+	       (skb = skb_dequeue(&offload->skb_queue))) {
+		struct can_frame *cf = (struct can_frame *)skb->data;
+
+		work_done++;
+		if (!(cf->can_id & CAN_ERR_FLAG)) {
+			stats->rx_packets++;
+			if (!(cf->can_id & CAN_RTR_FLAG))
+				stats->rx_bytes += cf->len;
+		}
+		netif_receive_skb(skb);
+	}
+
+	if (work_done < quota) {
+		napi_complete_done(napi, work_done);
+
+		/* Check if there was another interrupt */
+		if (!skb_queue_empty(&offload->skb_queue))
+			napi_schedule(&offload->napi);
+	}
+
+	return work_done;
+}
+
+static inline void
+__skb_queue_add_sort(struct sk_buff_head *head, struct sk_buff *new,
+		     int (*compare)(struct sk_buff *a, struct sk_buff *b))
+{
+	struct sk_buff *pos, *insert = NULL;
+
+	skb_queue_reverse_walk(head, pos) {
+		const struct can_rx_offload_cb *cb_pos, *cb_new;
+
+		cb_pos = can_rx_offload_get_cb(pos);
+		cb_new = can_rx_offload_get_cb(new);
+
+		netdev_dbg(new->dev,
+			   "%s: pos=0x%08x, new=0x%08x, diff=%10d, queue_len=%d\n",
+			   __func__,
+			   cb_pos->timestamp, cb_new->timestamp,
+			   cb_new->timestamp - cb_pos->timestamp,
+			   skb_queue_len(head));
+
+		if (compare(pos, new) < 0)
+			continue;
+		insert = pos;
+		break;
+	}
+	if (!insert)
+		__skb_queue_head(head, new);
+	else
+		__skb_queue_after(head, insert, new);
+}
+
+static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b)
+{
+	const struct can_rx_offload_cb *cb_a, *cb_b;
+
+	cb_a = can_rx_offload_get_cb(a);
+	cb_b = can_rx_offload_get_cb(b);
+
+	/* Subtract two u32 and return result as int, to keep
+	 * difference steady around the u32 overflow.
+	 */
+	return cb_b->timestamp - cb_a->timestamp;
+}
+
+/**
+ * can_rx_offload_offload_one() - Read one CAN frame from HW
+ * @offload: pointer to rx_offload context
+ * @n: number of mailbox to read
+ *
+ * The task of this function is to read a CAN frame from mailbox @n
+ * from the device and return the mailbox's content as a struct
+ * sk_buff.
+ *
+ * If the struct can_rx_offload::skb_queue exceeds the maximal queue
+ * length (struct can_rx_offload::skb_queue_len_max) or no skb can be
+ * allocated, the mailbox contents is discarded by reading it into an
+ * overflow buffer. This way the mailbox is marked as free by the
+ * driver.
+ *
+ * Return: A pointer to skb containing the CAN frame on success.
+ *
+ *         NULL if the mailbox @n is empty.
+ *
+ *         ERR_PTR() in case of an error
+ */
+static struct sk_buff *
+can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
+{
+	struct sk_buff *skb;
+	struct can_rx_offload_cb *cb;
+	bool drop = false;
+	u32 timestamp;
+
+	/* If queue is full drop frame */
+	if (unlikely(skb_queue_len(&offload->skb_queue) >
+		     offload->skb_queue_len_max))
+		drop = true;
+
+	skb = offload->mailbox_read(offload, n, &timestamp, drop);
+	/* Mailbox was empty. */
+	if (unlikely(!skb))
+		return NULL;
+
+	/* There was a problem reading the mailbox, propagate
+	 * error value.
+	 */
+	if (IS_ERR(skb)) {
+		offload->dev->stats.rx_dropped++;
+		offload->dev->stats.rx_fifo_errors++;
+
+		return skb;
+	}
+
+	/* Mailbox was read. */
+	cb = can_rx_offload_get_cb(skb);
+	cb->timestamp = timestamp;
+
+	return skb;
+}
+
+int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload,
+					 u64 pending)
+{
+	unsigned int i;
+	int received = 0;
+
+	for (i = offload->mb_first;
+	     can_rx_offload_le(offload, i, offload->mb_last);
+	     can_rx_offload_inc(offload, &i)) {
+		struct sk_buff *skb;
+
+		if (!(pending & BIT_ULL(i)))
+			continue;
+
+		skb = can_rx_offload_offload_one(offload, i);
+		if (IS_ERR_OR_NULL(skb))
+			continue;
+
+		__skb_queue_add_sort(&offload->skb_irq_queue, skb,
+				     can_rx_offload_compare);
+		received++;
+	}
+
+	return received;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_timestamp);
+
+int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload)
+{
+	struct sk_buff *skb;
+	int received = 0;
+
+	while (1) {
+		skb = can_rx_offload_offload_one(offload, 0);
+		if (IS_ERR(skb))
+			continue;
+		if (!skb)
+			break;
+
+		__skb_queue_tail(&offload->skb_irq_queue, skb);
+		received++;
+	}
+
+	return received;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_fifo);
+
+int can_rx_offload_queue_timestamp(struct can_rx_offload *offload,
+				   struct sk_buff *skb, u32 timestamp)
+{
+	struct can_rx_offload_cb *cb;
+
+	if (skb_queue_len(&offload->skb_queue) >
+	    offload->skb_queue_len_max) {
+		dev_kfree_skb_any(skb);
+		return -ENOBUFS;
+	}
+
+	cb = can_rx_offload_get_cb(skb);
+	cb->timestamp = timestamp;
+
+	__skb_queue_add_sort(&offload->skb_irq_queue, skb,
+			     can_rx_offload_compare);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_queue_timestamp);
+
+unsigned int
+can_rx_offload_get_echo_skb_queue_timestamp(struct can_rx_offload *offload,
+					    unsigned int idx, u32 timestamp,
+					    unsigned int *frame_len_ptr)
+{
+	struct net_device *dev = offload->dev;
+	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *skb;
+	unsigned int len;
+	int err;
+
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
+	if (!skb)
+		return 0;
+
+	err = can_rx_offload_queue_timestamp(offload, skb, timestamp);
+	if (err) {
+		stats->rx_errors++;
+		stats->tx_fifo_errors++;
+	}
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_get_echo_skb_queue_timestamp);
+
+int can_rx_offload_queue_tail(struct can_rx_offload *offload,
+			      struct sk_buff *skb)
+{
+	if (skb_queue_len(&offload->skb_queue) >
+	    offload->skb_queue_len_max) {
+		dev_kfree_skb_any(skb);
+		return -ENOBUFS;
+	}
+
+	__skb_queue_tail(&offload->skb_irq_queue, skb);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_queue_tail);
+
+unsigned int
+can_rx_offload_get_echo_skb_queue_tail(struct can_rx_offload *offload,
+				       unsigned int idx,
+				       unsigned int *frame_len_ptr)
+{
+	struct net_device *dev = offload->dev;
+	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *skb;
+	unsigned int len;
+	int err;
+
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
+	if (!skb)
+		return 0;
+
+	err = can_rx_offload_queue_tail(offload, skb);
+	if (err) {
+		stats->rx_errors++;
+		stats->tx_fifo_errors++;
+	}
+
+	return len;
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_get_echo_skb_queue_tail);
+
+void can_rx_offload_irq_finish(struct can_rx_offload *offload)
+{
+	unsigned long flags;
+	int queue_len;
+
+	if (skb_queue_empty_lockless(&offload->skb_irq_queue))
+		return;
+
+	spin_lock_irqsave(&offload->skb_queue.lock, flags);
+	skb_queue_splice_tail_init(&offload->skb_irq_queue, &offload->skb_queue);
+	spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
+
+	queue_len = skb_queue_len(&offload->skb_queue);
+	if (queue_len > offload->skb_queue_len_max / 8)
+		netdev_dbg(offload->dev, "%s: queue_len=%d\n",
+			   __func__, queue_len);
+
+	napi_schedule(&offload->napi);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_irq_finish);
+
+void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload)
+{
+	unsigned long flags;
+	int queue_len;
+
+	if (skb_queue_empty_lockless(&offload->skb_irq_queue))
+		return;
+
+	spin_lock_irqsave(&offload->skb_queue.lock, flags);
+	skb_queue_splice_tail_init(&offload->skb_irq_queue, &offload->skb_queue);
+	spin_unlock_irqrestore(&offload->skb_queue.lock, flags);
+
+	queue_len = skb_queue_len(&offload->skb_queue);
+	if (queue_len > offload->skb_queue_len_max / 8)
+		netdev_dbg(offload->dev, "%s: queue_len=%d\n",
+			   __func__, queue_len);
+
+	local_bh_disable();
+	napi_schedule(&offload->napi);
+	local_bh_enable();
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_threaded_irq_finish);
+
+static int can_rx_offload_init_queue(struct net_device *dev,
+				     struct can_rx_offload *offload,
+				     unsigned int weight)
+{
+	offload->dev = dev;
+
+	/* Limit queue len to 4x the weight (rounded to next power of two) */
+	offload->skb_queue_len_max = 2 << fls(weight);
+	offload->skb_queue_len_max *= 4;
+	skb_queue_head_init(&offload->skb_queue);
+	__skb_queue_head_init(&offload->skb_irq_queue);
+
+	netif_napi_add_weight(dev, &offload->napi, can_rx_offload_napi_poll,
+			      weight);
+
+	dev_dbg(dev->dev.parent, "%s: skb_queue_len_max=%d\n",
+		__func__, offload->skb_queue_len_max);
+
+	return 0;
+}
+
+int can_rx_offload_add_timestamp(struct net_device *dev,
+				 struct can_rx_offload *offload)
+{
+	unsigned int weight;
+
+	if (offload->mb_first > BITS_PER_LONG_LONG ||
+	    offload->mb_last > BITS_PER_LONG_LONG || !offload->mailbox_read)
+		return -EINVAL;
+
+	if (offload->mb_first < offload->mb_last) {
+		offload->inc = true;
+		weight = offload->mb_last - offload->mb_first;
+	} else {
+		offload->inc = false;
+		weight = offload->mb_first - offload->mb_last;
+	}
+
+	return can_rx_offload_init_queue(dev, offload, weight);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_add_timestamp);
+
+int can_rx_offload_add_fifo(struct net_device *dev,
+			    struct can_rx_offload *offload, unsigned int weight)
+{
+	if (!offload->mailbox_read)
+		return -EINVAL;
+
+	return can_rx_offload_init_queue(dev, offload, weight);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_add_fifo);
+
+int can_rx_offload_add_manual(struct net_device *dev,
+			      struct can_rx_offload *offload,
+			      unsigned int weight)
+{
+	if (offload->mailbox_read)
+		return -EINVAL;
+
+	return can_rx_offload_init_queue(dev, offload, weight);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_add_manual);
+
+void can_rx_offload_enable(struct can_rx_offload *offload)
+{
+	napi_enable(&offload->napi);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_enable);
+
+void can_rx_offload_del(struct can_rx_offload *offload)
+{
+	netif_napi_del(&offload->napi);
+	skb_queue_purge(&offload->skb_queue);
+	__skb_queue_purge(&offload->skb_irq_queue);
+}
+EXPORT_SYMBOL_GPL(can_rx_offload_del);

linux-7.2.3/drivers/net/can/dev/skb.c

@@ -0,0 +1,405 @@
+// 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 <linux/module.h>
+#include <net/can.h>
+
+#define MOD_DESC "CAN device driver interface"
+
+MODULE_DESCRIPTION(MOD_DESC);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
+
+/* 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, unsigned int frame_len)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct can_skb_ext *csx;
+
+	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 -EINVAL;
+	}
+
+	/* check flag whether this packet has to be looped back */
+	if (!(dev->flags & IFF_ECHO) ||
+	    (skb->protocol != htons(ETH_P_CAN) &&
+	     skb->protocol != htons(ETH_P_CANFD) &&
+	     skb->protocol != htons(ETH_P_CANXL))) {
+		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->ip_summed = CHECKSUM_UNNECESSARY;
+		skb->dev = dev;
+
+		/* save frame_len to reuse it when transmission is completed */
+		csx = can_skb_ext_find(skb);
+		if (csx)
+			csx->can_framelen = frame_len;
+
+		if (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP)
+			skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+
+		skb_tx_timestamp(skb);
+
+		/* 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,
+		   unsigned int *len_ptr, unsigned int *frame_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 can_skb_ext *csx;
+
+		if (skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)
+			skb_tstamp_tx(skb, skb_hwtstamps(skb));
+
+		/* get the real payload length for netdev statistics */
+		*len_ptr = can_skb_get_data_len(skb);
+
+		if (frame_len_ptr) {
+			csx = can_skb_ext_find(skb);
+			if (csx)
+				*frame_len_ptr = csx->can_framelen;
+			else
+				*frame_len_ptr = 0;
+		}
+
+		priv->echo_skb[idx] = NULL;
+
+		if (skb->pkt_type == PACKET_LOOPBACK) {
+			skb->pkt_type = PACKET_BROADCAST;
+		} else {
+			dev_consume_skb_any(skb);
+			return 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,
+			      unsigned int *frame_len_ptr)
+{
+	struct sk_buff *skb;
+	unsigned int len;
+
+	skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr);
+	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,
+		       unsigned int *frame_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;
+	}
+
+	if (priv->echo_skb[idx]) {
+		struct sk_buff *skb = priv->echo_skb[idx];
+		struct can_skb_ext *csx;
+
+		if (frame_len_ptr) {
+			csx = can_skb_ext_find(skb);
+			if (csx)
+				*frame_len_ptr = csx->can_framelen;
+			else
+				*frame_len_ptr = 0;
+		}
+
+		dev_kfree_skb_any(skb);
+		priv->echo_skb[idx] = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(can_free_echo_skb);
+
+/* fill common values for CAN sk_buffs */
+static void init_can_skb(struct sk_buff *skb)
+{
+	skb->pkt_type = PACKET_BROADCAST;
+	skb->ip_summed = CHECKSUM_UNNECESSARY;
+}
+
+struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct can_frame));
+	if (unlikely(!skb))
+		goto out_error_cc;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		goto out_error_cc;
+	}
+
+	skb->protocol = htons(ETH_P_CAN);
+	init_can_skb(skb);
+	csx->can_iif = dev->ifindex;
+
+	*cf = skb_put_zero(skb, sizeof(struct can_frame));
+
+	return skb;
+
+out_error_cc:
+	*cf = NULL;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(alloc_can_skb);
+
+struct sk_buff *alloc_canfd_skb(struct net_device *dev,
+				struct canfd_frame **cfd)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+
+	skb = netdev_alloc_skb(dev, sizeof(struct canfd_frame));
+	if (unlikely(!skb))
+		goto out_error_fd;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		goto out_error_fd;
+	}
+
+	skb->protocol = htons(ETH_P_CANFD);
+	init_can_skb(skb);
+	csx->can_iif = dev->ifindex;
+
+	*cfd = skb_put_zero(skb, sizeof(struct canfd_frame));
+
+	/* set CAN FD flag by default */
+	(*cfd)->flags = CANFD_FDF;
+
+	return skb;
+
+out_error_fd:
+	*cfd = NULL;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(alloc_canfd_skb);
+
+struct sk_buff *alloc_canxl_skb(struct net_device *dev,
+				struct canxl_frame **cxl,
+				unsigned int data_len)
+{
+	struct sk_buff *skb;
+	struct can_skb_ext *csx;
+
+	if (data_len < CANXL_MIN_DLEN || data_len > CANXL_MAX_DLEN)
+		goto out_error_xl;
+
+	skb = netdev_alloc_skb(dev, CANXL_HDR_SIZE + data_len);
+	if (unlikely(!skb))
+		goto out_error_xl;
+
+	csx = can_skb_ext_add(skb);
+	if (!csx) {
+		kfree_skb(skb);
+		goto out_error_xl;
+	}
+
+	skb->protocol = htons(ETH_P_CANXL);
+	init_can_skb(skb);
+	csx->can_iif = dev->ifindex;
+
+	*cxl = skb_put_zero(skb, CANXL_HDR_SIZE + data_len);
+
+	/* set CAN XL flag and length information by default */
+	(*cxl)->flags = CANXL_XLF;
+	(*cxl)->len = data_len;
+
+	return skb;
+
+out_error_xl:
+	*cxl = NULL;
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(alloc_canxl_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);
+
+/* Check for outgoing skbs that have not been created by the CAN subsystem */
+static bool can_skb_init_valid(struct net_device *dev, struct sk_buff *skb)
+{
+	struct can_skb_ext *csx = can_skb_ext_find(skb);
+
+	/* af_packet does not apply CAN skb specific settings */
+	if (skb->ip_summed == CHECKSUM_NONE || !csx) {
+		/* init CAN skb content */
+		if (!csx) {
+			csx = can_skb_ext_add(skb);
+			if (!csx)
+				return false;
+		}
+
+		csx->can_iif = dev->ifindex;
+		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);
+
+		/* set CANFD_FDF flag for CAN FD frames */
+		if (can_is_canfd_skb(skb)) {
+			struct canfd_frame *cfd;
+
+			cfd = (struct canfd_frame *)skb->data;
+			cfd->flags |= CANFD_FDF;
+		}
+	}
+
+	return true;
+}
+
+/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
+bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
+{
+	switch (ntohs(skb->protocol)) {
+	case ETH_P_CAN:
+		if (!can_is_can_skb(skb))
+			goto inval_skb;
+		break;
+
+	case ETH_P_CANFD:
+		if (!can_is_canfd_skb(skb))
+			goto inval_skb;
+		break;
+
+	case ETH_P_CANXL:
+		if (!can_is_canxl_skb(skb))
+			goto inval_skb;
+		break;
+
+	default:
+		goto inval_skb;
+	}
+
+	if (!can_skb_init_valid(dev, skb))
+		goto inval_skb;
+
+	return false;
+
+inval_skb:
+	kfree_skb(skb);
+	dev->stats.tx_dropped++;
+	return true;
+}
+EXPORT_SYMBOL_GPL(can_dropped_invalid_skb);