can: netlink: add initial CAN XL support

CAN XL uses bittiming parameters different from Classical CAN and CAN
FD. Thus, all the data bittiming parameters, including TDC, need to be
duplicated for CAN XL.

Add the CAN XL netlink interface for all the features which are common
with CAN FD. Any new CAN XL specific features are added later on.

The first time CAN XL is activated, the MTU is set by default to
CANXL_MAX_MTU. The user may then configure a custom MTU within the
CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU
value will be kept as long as CAN XL remains active.

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

2 files changed, 73 insertions, 17 deletions

diff --git a/drivers/net/can/dev/dev.c b/drivers/net/can/dev/dev.c
index b6980d32e5b4..bdec2c52c8ec 100644
--- a/drivers/net/can/dev/dev.c
+++ b/drivers/net/can/dev/dev.c
@@ -117,6 +117,12 @@ const char *can_get_ctrlmode_str(u32 ctrlmode)
 		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";
 	default:
 		return "<unknown>";
 	}
@@ -350,7 +356,13 @@ void can_set_default_mtu(struct net_device *dev)
 {
 	struct can_priv *priv = netdev_priv(dev);
 
-	if (priv->ctrlmode & CAN_CTRLMODE_FD) {
+	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;
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index 87e731527dd7..fdd1fa7cf93a 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -2,7 +2,7 @@
 /* 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 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
+ * Copyright (C) 2021-2025 Vincent Mailhol <mailhol@kernel.org>
  */
 
 #include <linux/can/dev.h>
@@ -22,6 +22,9 @@ static const struct nla_policy can_policy[IFLA_CAN_MAX + 1] = {
 	[IFLA_CAN_TERMINATION] = { .type = NLA_U16 },
 	[IFLA_CAN_TDC] = { .type = NLA_NESTED },
 	[IFLA_CAN_CTRLMODE_EXT] = { .type = NLA_NESTED },
+	[IFLA_CAN_XL_DATA_BITTIMING] = { .len = sizeof(struct can_bittiming) },
+	[IFLA_CAN_XL_DATA_BITTIMING_CONST] = { .len = sizeof(struct can_bittiming_const) },
+	[IFLA_CAN_XL_TDC] = { .type = NLA_NESTED },
 };
 
 static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = {
@@ -70,7 +73,7 @@ static int can_validate_tdc(struct nlattr *data_tdc,
 		return -EOPNOTSUPP;
 	}
 
-	/* If one of the CAN_CTRLMODE_TDC_* flag is set then TDC
+	/* If one of the CAN_CTRLMODE_{,XL}_TDC_* flags is set then TDC
 	 * must be set and vice-versa
 	 */
 	if ((tdc_auto || tdc_manual) && !data_tdc) {
@@ -82,8 +85,8 @@ static int can_validate_tdc(struct nlattr *data_tdc,
 		return -EOPNOTSUPP;
 	}
 
-	/* If providing TDC parameters, at least TDCO is needed. TDCV
-	 * is needed if and only if CAN_CTRLMODE_TDC_MANUAL is set
+	/* If providing TDC parameters, at least TDCO is needed. TDCV is
+	 * needed if and only if CAN_CTRLMODE_{,XL}_TDC_MANUAL is set
 	 */
 	if (data_tdc) {
 		struct nlattr *tb_tdc[IFLA_CAN_TDC_MAX + 1];
@@ -126,10 +129,10 @@ static int can_validate_databittiming(struct nlattr *data[],
 	bool is_on;
 	int err;
 
-	/* Make sure that valid CAN FD configurations always consist of
+	/* Make sure that valid CAN FD/XL configurations always consist of
 	 * - nominal/arbitration bittiming
 	 * - data bittiming
-	 * - control mode with CAN_CTRLMODE_FD set
+	 * - control mode with CAN_CTRLMODE_{FD,XL} set
 	 * - TDC parameters are coherent (details in can_validate_tdc())
 	 */
 
@@ -139,7 +142,10 @@ static int can_validate_databittiming(struct nlattr *data[],
 		is_on = flags & CAN_CTRLMODE_FD;
 		type = "FD";
 	} else {
-		return -EOPNOTSUPP; /* Place holder for CAN XL */
+		data_tdc = data[IFLA_CAN_XL_TDC];
+		tdc_flags = flags & CAN_CTRLMODE_XL_TDC_MASK;
+		is_on = flags & CAN_CTRLMODE_XL;
+		type = "XL";
 	}
 
 	if (is_on) {
@@ -206,6 +212,11 @@ static int can_validate(struct nlattr *tb[], struct nlattr *data[],
 	if (err)
 		return err;
 
+	err = can_validate_databittiming(data, extack,
+					 IFLA_CAN_XL_DATA_BITTIMING, flags);
+	if (err)
+		return err;
+
 	return 0;
 }
 
@@ -251,18 +262,26 @@ static int can_ctrlmode_changelink(struct net_device *dev,
 	/* If a top dependency flag is provided, reset all its dependencies */
 	if (cm->mask & CAN_CTRLMODE_FD)
 		priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK;
+	if (cm->mask & CAN_CTRLMODE_XL)
+		priv->ctrlmode &= ~(CAN_CTRLMODE_XL_TDC_MASK);
 
 	/* clear bits to be modified and copy the flag values */
 	priv->ctrlmode &= ~cm->mask;
 	priv->ctrlmode |= maskedflags;
 
-	/* Wipe potential leftovers from previous CAN FD config */
+	/* Wipe potential leftovers from previous CAN FD/XL config */
 	if (!(priv->ctrlmode & CAN_CTRLMODE_FD)) {
 		memset(&priv->fd.data_bittiming, 0,
 		       sizeof(priv->fd.data_bittiming));
 		priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK;
 		memset(&priv->fd.tdc, 0, sizeof(priv->fd.tdc));
 	}
+	if (!(priv->ctrlmode & CAN_CTRLMODE_XL)) {
+		memset(&priv->xl.data_bittiming, 0,
+		       sizeof(priv->fd.data_bittiming));
+		priv->ctrlmode &= ~CAN_CTRLMODE_XL_TDC_MASK;
+		memset(&priv->xl.tdc, 0, sizeof(priv->xl.tdc));
+	}
 
 	can_set_default_mtu(dev);
 
@@ -337,7 +356,10 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[],
 		dbt_params = &priv->fd;
 		tdc_mask = CAN_CTRLMODE_FD_TDC_MASK;
 	} else {
-		return -EOPNOTSUPP; /* Place holder for CAN XL */
+		data_bittiming = data[IFLA_CAN_XL_DATA_BITTIMING];
+		data_tdc = data[IFLA_CAN_XL_TDC];
+		dbt_params = &priv->xl;
+		tdc_mask = CAN_CTRLMODE_XL_TDC_MASK;
 	}
 
 	if (!data_bittiming)
@@ -388,7 +410,7 @@ static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[],
 		 */
 		can_calc_tdco(&dbt_params->tdc, dbt_params->tdc_const, &dbt,
 			      tdc_mask, &priv->ctrlmode, priv->ctrlmode_supported);
-	} /* else: both CAN_CTRLMODE_TDC_{AUTO,MANUAL} are explicitly
+	} /* else: both CAN_CTRLMODE_{,XL}_TDC_{AUTO,MANUAL} are explicitly
 	   * turned off. TDC is disabled: do nothing
 	   */
 
@@ -493,6 +515,11 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (err)
 		return err;
 
+	/* CAN XL */
+	err = can_dbt_changelink(dev, data, false, extack);
+	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;
@@ -560,14 +587,14 @@ static size_t can_data_bittiming_get_size(struct data_bittiming_params *dbt_para
 {
 	size_t size = 0;
 
-	if (dbt_params->data_bittiming.bitrate)		/* IFLA_CAN_DATA_BITTIMING */
+	if (dbt_params->data_bittiming.bitrate)		/* IFLA_CAN_{,XL}_DATA_BITTIMING */
 		size += nla_total_size(sizeof(dbt_params->data_bittiming));
-	if (dbt_params->data_bittiming_const)		/* IFLA_CAN_DATA_BITTIMING_CONST */
+	if (dbt_params->data_bittiming_const)		/* IFLA_CAN_{,XL}_DATA_BITTIMING_CONST */
 		size += nla_total_size(sizeof(*dbt_params->data_bittiming_const));
-	if (dbt_params->data_bitrate_const)		/* IFLA_CAN_DATA_BITRATE_CONST */
+	if (dbt_params->data_bitrate_const)		/* IFLA_CAN_{,XL}_DATA_BITRATE_CONST */
 		size += nla_total_size(sizeof(*dbt_params->data_bitrate_const) *
 				       dbt_params->data_bitrate_const_cnt);
-	size += can_tdc_get_size(dbt_params, tdc_flags);/* IFLA_CAN_TDC */
+	size += can_tdc_get_size(dbt_params, tdc_flags);/* IFLA_CAN_{,XL}_TDC */
 
 	return size;
 }
@@ -607,6 +634,9 @@ static size_t can_get_size(const struct net_device *dev)
 	size += can_data_bittiming_get_size(&priv->fd,
 					    priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK);
 
+	size += can_data_bittiming_get_size(&priv->xl,
+					    priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MASK);
+
 	return size;
 }
 
@@ -651,7 +681,9 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev,
 		tdc_is_enabled = can_fd_tdc_is_enabled(priv);
 		tdc_manual = priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL;
 	} else {
-		return -EOPNOTSUPP; /* Place holder for CAN XL */
+		dbt_params = &priv->xl;
+		tdc_is_enabled = can_xl_tdc_is_enabled(priv);
+		tdc_manual = priv->ctrlmode & CAN_CTRLMODE_XL_TDC_MANUAL;
 	}
 	tdc_const = dbt_params->tdc_const;
 	tdc = &dbt_params->tdc;
@@ -773,7 +805,19 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 
 	    can_tdc_fill_info(skb, dev, IFLA_CAN_TDC) ||
 
-	    can_ctrlmode_ext_fill_info(skb, priv)
+	    can_ctrlmode_ext_fill_info(skb, priv) ||
+
+	    can_bittiming_fill_info(skb, IFLA_CAN_XL_DATA_BITTIMING,
+				    &priv->xl.data_bittiming) ||
+
+	    can_bittiming_const_fill_info(skb, IFLA_CAN_XL_DATA_BITTIMING_CONST,
+					  priv->xl.data_bittiming_const) ||
+
+	    can_bitrate_const_fill_info(skb, IFLA_CAN_XL_DATA_BITRATE_CONST,
+					priv->xl.data_bitrate_const,
+					priv->xl.data_bitrate_const_cnt) ||
+
+	    can_tdc_fill_info(skb, dev, IFLA_CAN_XL_TDC)
 	    )
 
 		return -EMSGSIZE;