Merge tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "Core & protocols:

   - Improve drop account scalability on NUMA hosts for RAW and UDP
     sockets and the backlog, almost doubling the Pps capacity under DoS

   - Optimize the UDP RX performance under stress, reducing contention,
     revisiting the binary layout of the involved data structs and
     implementing NUMA-aware locking. This improves UDP RX performance
     by an additional 50%, even more under extreme conditions

   - Add support for PSP encryption of TCP connections; this mechanism
     has some similarities with IPsec and TLS, but offers superior HW
     offloads capabilities

   - Ongoing work to support Accurate ECN for TCP. AccECN allows more
     than one congestion notification signal per RTT and is a building
     block for Low Latency, Low Loss, and Scalable Throughput (L4S)

   - Reorganize the TCP socket binary layout for data locality, reducing
     the number of touched cachelines in the fastpath

   - Refactor skb deferral free to better scale on large multi-NUMA
     hosts, this improves TCP and UDP RX performances significantly on
     such HW

   - Increase the default socket memory buffer limits from 256K to 4M to
     better fit modern link speeds

   - Improve handling of setups with a large number of nexthop, making
     dump operating scaling linearly and avoiding unneeded
     synchronize_rcu() on delete

   - Improve bridge handling of VLAN FDB, storing a single entry per
     bridge instead of one entry per port; this makes the dump order of
     magnitude faster on large switches

   - Restore IP ID correctly for encapsulated packets at GSO
     segmentation time, allowing GRO to merge packets in more scenarios

   - Improve netfilter matching performance on large sets

   - Improve MPTCP receive path performance by leveraging recently
     introduced core infrastructure (skb deferral free) and adopting
     recent TCP autotuning changes

   - Allow bridges to redirect to a backup port when the bridge port is
     administratively down

   - Introduce MPTCP 'laminar' endpoint that con be used only once per
     connection and simplify common MPTCP setups

   - Add RCU safety to dst->dev, closing a lot of possible races

   - A significant crypto library API for SCTP, MPTCP and IPv6 SR,
     reducing code duplication

   - Supports pulling data from an skb frag into the linear area of an
     XDP buffer

  Things we sprinkled into general kernel code:

   - Generate netlink documentation from YAML using an integrated YAML
     parser

  Driver API:

   - Support using IPv6 Flow Label in Rx hash computation and RSS queue
     selection

   - Introduce API for fetching the DMA device for a given queue,
     allowing TCP zerocopy RX on more H/W setups

   - Make XDP helpers compatible with unreadable memory, allowing more
     easily building DevMem-enabled drivers with a unified XDP/skbs
     datapath

   - Add a new dedicated ethtool callback enabling drivers to provide
     the number of RX rings directly, improving efficiency and clarity
     in RX ring queries and RSS configuration

   - Introduce a burst period for the health reporter, allowing better
     handling of multiple errors due to the same root cause

   - Support for DPLL phase offset exponential moving average,
     controlling the average smoothing factor

  Device drivers:

   - Add a new Huawei driver for 3rd gen NIC (hinic3)

   - Add a new SpacemiT driver for K1 ethernet MAC

   - Add a generic abstraction for shared memory communication
     devices (dibps)

   - Ethernet high-speed NICs:
      - nVidia/Mellanox:
         - Use multiple per-queue doorbell, to avoid MMIO contention
           issues
         - support adjacent functions, allowing them to delegate their
           SR-IOV VFs to sibling PFs
         - support RSS for IPSec offload
         - support exposing raw cycle counters in PTP and mlx5
         - support for disabling host PFs.
      - Intel (100G, ice, idpf):
         - ice: support for SRIOV VFs over an Active-Active link
           aggregate
         - ice: support for firmware logging via debugfs
         - ice: support for Earliest TxTime First (ETF) hardware offload
         - idpf: support basic XDP functionalities and XSk
      - Broadcom (bnxt):
         - support Hyper-V VF ID
         - dynamic SRIOV resource allocations for RoCE
      - Meta (fbnic):
         - support queue API, zero-copy Rx and Tx
         - support basic XDP functionalities
         - devlink health support for FW crashes and OTP mem corruptions
         - expand hardware stats coverage to FEC, PHY, and Pause
      - Wangxun:
         - support ethtool coalesce options
         - support for multiple RSS contexts

   - Ethernet virtual:
      - Macsec:
         - replace custom netlink attribute checks with policy-level
           checks
      - Bonding:
         - support aggregator selection based on port priority
      - Microsoft vNIC:
         - use page pool fragments for RX buffers instead of full pages
           to improve memory efficiency

   - Ethernet NICs consumer, and embedded:
      - Qualcomm: support Ethernet function for IPQ9574 SoC
      - Airoha: implement wlan offloading via NPU
      - Freescale
         - enetc: add NETC timer PTP driver and add PTP support
         - fec: enable the Jumbo frame support for i.MX8QM
      - Renesas (R-Car S4):
         - support HW offloading for layer 2 switching
         - support for RZ/{T2H, N2H} SoCs
      - Cadence (macb): support TAPRIO traffic scheduling
      - TI:
         - support for Gigabit ICSS ethernet SoC (icssm-prueth)
      - Synopsys (stmmac): a lot of cleanups

   - Ethernet PHYs:
      - Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS
        driver
      - Support bcm63268 GPHY power control
      - Support for Micrel lan8842 PHY and PTP
      - Support for Aquantia AQR412 and AQR115

   - CAN:
      - a large CAN-XL preparation work
      - reorganize raw_sock and uniqframe struct to minimize memory
        usage
      - rcar_canfd: update the CAN-FD handling

   - WiFi:
      - extended Neighbor Awareness Networking (NAN) support
      - S1G channel representation cleanup
      - improve S1G support

   - WiFi drivers:
      - Intel (iwlwifi):
         - major refactor and cleanup
      - Broadcom (brcm80211):
         - support for AP isolation
      - RealTek (rtw88/89) rtw88/89:
         - preparation work for RTL8922DE support
      - MediaTek (mt76):
         - HW restart improvements
         - MLO support
      - Qualcomm/Atheros (ath10k):
         - GTK rekey fixes

   - Bluetooth drivers:
      - btusb: support for several new IDs for MT7925
      - btintel: support for BlazarIW core
      - btintel_pcie: support for _suspend() / _resume()
      - btintel_pcie: support for Scorpious, Panther Lake-H484 IDs"

* tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1536 commits)
  net: stmmac: Add support for Allwinner A523 GMAC200
  dt-bindings: net: sun8i-emac: Add A523 GMAC200 compatible
  Revert "Documentation: net: add flow control guide and document ethtool API"
  octeontx2-pf: fix bitmap leak
  octeontx2-vf: fix bitmap leak
  net/mlx5e: Use extack in set rxfh callback
  net/mlx5e: Introduce mlx5e_rss_params for RSS configuration
  net/mlx5e: Introduce mlx5e_rss_init_params
  net/mlx5e: Remove unused mdev param from RSS indir init
  net/mlx5: Improve QoS error messages with actual depth values
  net/mlx5e: Prevent entering switchdev mode with inconsistent netns
  net/mlx5: HWS, Generalize complex matchers
  net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs
  selftests/net: add tcp_port_share to .gitignore
  Revert "net/mlx5e: Update and set Xon/Xoff upon MTU set"
  net: add NUMA awareness to skb_attempt_defer_free()
  net: use llist for sd->defer_list
  net: make softnet_data.defer_count an atomic
  selftests: drv-net: psp: add tests for destroying devices
  selftests: drv-net: psp: add test for auto-adjusting TCP MSS
  ...

1 files changed, 373 insertions, 219 deletions

diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index d9f6ab3efb97..0591406b6f32 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -36,116 +36,245 @@ static const struct nla_policy can_tdc_policy[IFLA_CAN_TDC_MAX + 1] = {
 	[IFLA_CAN_TDC_TDCF] = { .type = NLA_U32 },
 };
 
-static int can_validate_bittiming(const struct can_bittiming *bt,
-				  struct netlink_ext_ack *extack)
+static int can_validate_bittiming(struct nlattr *data[],
+				  struct netlink_ext_ack *extack,
+				  int ifla_can_bittiming)
 {
+	struct can_bittiming *bt;
+
+	if (!data[ifla_can_bittiming])
+		return 0;
+
+	static_assert(__alignof__(*bt) <= NLA_ALIGNTO);
+	bt = nla_data(data[ifla_can_bittiming]);
+
 	/* sample point is in one-tenth of a percent */
 	if (bt->sample_point >= 1000) {
 		NL_SET_ERR_MSG(extack, "sample point must be between 0 and 100%");
-
 		return -EINVAL;
 	}
 
 	return 0;
 }
 
-static int can_validate(struct nlattr *tb[], struct nlattr *data[],
-			struct netlink_ext_ack *extack)
+static int can_validate_tdc(struct nlattr *data_tdc,
+			    struct netlink_ext_ack *extack, u32 tdc_flags)
 {
-	bool is_can_fd = false;
+	bool tdc_manual = tdc_flags & CAN_CTRLMODE_TDC_MANUAL_MASK;
+	bool tdc_auto = tdc_flags & CAN_CTRLMODE_TDC_AUTO_MASK;
+	int err;
+
+	if (tdc_auto && tdc_manual) {
+		NL_SET_ERR_MSG(extack,
+			       "TDC manual and auto modes are mutually exclusive");
+		return -EOPNOTSUPP;
+	}
+
+	/* If one of the CAN_CTRLMODE_TDC_* flag is set then TDC
+	 * must be set and vice-versa
+	 */
+	if ((tdc_auto || tdc_manual) && !data_tdc) {
+		NL_SET_ERR_MSG(extack, "TDC parameters are missing");
+		return -EOPNOTSUPP;
+	}
+	if (!(tdc_auto || tdc_manual) && data_tdc) {
+		NL_SET_ERR_MSG(extack, "TDC mode (auto or manual) is missing");
+		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 (data_tdc) {
+		struct nlattr *tb_tdc[IFLA_CAN_TDC_MAX + 1];
+
+		err = nla_parse_nested(tb_tdc, IFLA_CAN_TDC_MAX,
+				       data_tdc, can_tdc_policy, extack);
+		if (err)
+			return err;
+
+		if (tb_tdc[IFLA_CAN_TDC_TDCV]) {
+			if (tdc_auto) {
+				NL_SET_ERR_MSG(extack,
+					       "TDCV is incompatible with TDC auto mode");
+				return -EOPNOTSUPP;
+			}
+		} else {
+			if (tdc_manual) {
+				NL_SET_ERR_MSG(extack,
+					       "TDC manual mode requires TDCV");
+				return -EOPNOTSUPP;
+			}
+		}
+
+		if (!tb_tdc[IFLA_CAN_TDC_TDCO]) {
+			NL_SET_ERR_MSG(extack, "TDCO is missing");
+			return -EOPNOTSUPP;
+		}
+	}
+
+	return 0;
+}
+
+static int can_validate_databittiming(struct nlattr *data[],
+				      struct netlink_ext_ack *extack,
+				      int ifla_can_data_bittiming, u32 flags)
+{
+	struct nlattr *data_tdc;
+	const char *type;
+	u32 tdc_flags;
+	bool is_on;
 	int err;
 
 	/* Make sure that valid CAN FD configurations always consist of
 	 * - nominal/arbitration bittiming
 	 * - data bittiming
 	 * - control mode with CAN_CTRLMODE_FD set
-	 * - TDC parameters are coherent (details below)
+	 * - TDC parameters are coherent (details in can_validate_tdc())
 	 */
 
+	if (ifla_can_data_bittiming == IFLA_CAN_DATA_BITTIMING) {
+		data_tdc = data[IFLA_CAN_TDC];
+		tdc_flags = flags & CAN_CTRLMODE_FD_TDC_MASK;
+		is_on = flags & CAN_CTRLMODE_FD;
+		type = "FD";
+	} else {
+		return -EOPNOTSUPP; /* Place holder for CAN XL */
+	}
+
+	if (is_on) {
+		if (!data[IFLA_CAN_BITTIMING] || !data[ifla_can_data_bittiming]) {
+			NL_SET_ERR_MSG_FMT(extack,
+					   "Provide both nominal and %s data bittiming",
+					   type);
+			return -EOPNOTSUPP;
+		}
+	} else {
+		if (data[ifla_can_data_bittiming]) {
+			NL_SET_ERR_MSG_FMT(extack,
+					   "%s data bittiming requires CAN %s",
+					   type, type);
+			return -EOPNOTSUPP;
+		}
+		if (data_tdc) {
+			NL_SET_ERR_MSG_FMT(extack,
+					   "%s TDC requires CAN %s",
+					   type, type);
+			return -EOPNOTSUPP;
+		}
+	}
+
+	err = can_validate_bittiming(data, extack, ifla_can_data_bittiming);
+	if (err)
+		return err;
+
+	err = can_validate_tdc(data_tdc, extack, tdc_flags);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int can_validate(struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	u32 flags = 0;
+	int err;
+
 	if (!data)
 		return 0;
 
 	if (data[IFLA_CAN_CTRLMODE]) {
 		struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
-		u32 tdc_flags = cm->flags & CAN_CTRLMODE_FD_TDC_MASK;
 
-		is_can_fd = cm->flags & cm->mask & CAN_CTRLMODE_FD;
+		flags = cm->flags & cm->mask;
+	}
 
-		/* CAN_CTRLMODE_TDC_{AUTO,MANUAL} are mutually exclusive */
-		if (tdc_flags == CAN_CTRLMODE_FD_TDC_MASK)
-			return -EOPNOTSUPP;
-		/* If one of the CAN_CTRLMODE_TDC_* flag is set then
-		 * TDC must be set and vice-versa
-		 */
-		if (!!tdc_flags != !!data[IFLA_CAN_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 (data[IFLA_CAN_TDC]) {
-			struct nlattr *tb_tdc[IFLA_CAN_TDC_MAX + 1];
+	err = can_validate_bittiming(data, extack, IFLA_CAN_BITTIMING);
+	if (err)
+		return err;
 
-			err = nla_parse_nested(tb_tdc, IFLA_CAN_TDC_MAX,
-					       data[IFLA_CAN_TDC],
-					       can_tdc_policy, extack);
-			if (err)
-				return err;
+	err = can_validate_databittiming(data, extack,
+					 IFLA_CAN_DATA_BITTIMING, flags);
+	if (err)
+		return err;
 
-			if (tb_tdc[IFLA_CAN_TDC_TDCV]) {
-				if (tdc_flags & CAN_CTRLMODE_TDC_AUTO)
-					return -EOPNOTSUPP;
-			} else {
-				if (tdc_flags & CAN_CTRLMODE_TDC_MANUAL)
-					return -EOPNOTSUPP;
-			}
+	return 0;
+}
 
-			if (!tb_tdc[IFLA_CAN_TDC_TDCO])
-				return -EOPNOTSUPP;
-		}
-	}
+static int can_ctrlmode_changelink(struct net_device *dev,
+				   struct nlattr *data[],
+				   struct netlink_ext_ack *extack)
+{
+	struct can_priv *priv = netdev_priv(dev);
+	struct can_ctrlmode *cm;
+	u32 ctrlstatic, maskedflags, notsupp, ctrlstatic_missing;
 
-	if (data[IFLA_CAN_BITTIMING]) {
-		struct can_bittiming bt;
+	if (!data[IFLA_CAN_CTRLMODE])
+		return 0;
 
-		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));
-		err = can_validate_bittiming(&bt, extack);
-		if (err)
-			return err;
-	}
+	/* Do not allow changing controller mode while running */
+	if (dev->flags & IFF_UP)
+		return -EBUSY;
 
-	if (is_can_fd) {
-		if (!data[IFLA_CAN_BITTIMING] || !data[IFLA_CAN_DATA_BITTIMING])
-			return -EOPNOTSUPP;
+	cm = nla_data(data[IFLA_CAN_CTRLMODE]);
+	ctrlstatic = can_get_static_ctrlmode(priv);
+	maskedflags = cm->flags & cm->mask;
+	notsupp = maskedflags & ~(priv->ctrlmode_supported | ctrlstatic);
+	ctrlstatic_missing = (maskedflags & ctrlstatic) ^ ctrlstatic;
+
+	if (notsupp) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "requested control mode %s not supported",
+				   can_get_ctrlmode_str(notsupp));
+		return -EOPNOTSUPP;
 	}
 
-	if (data[IFLA_CAN_DATA_BITTIMING] || data[IFLA_CAN_TDC]) {
-		if (!is_can_fd)
-			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;
+
+	if (ctrlstatic_missing) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "missing required %s static control mode",
+				   can_get_ctrlmode_str(ctrlstatic_missing));
+		return -EOPNOTSUPP;
 	}
 
-	if (data[IFLA_CAN_DATA_BITTIMING]) {
-		struct can_bittiming bt;
+	/* If a top dependency flag is provided, reset all its dependencies */
+	if (cm->mask & CAN_CTRLMODE_FD)
+		priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK;
 
-		memcpy(&bt, nla_data(data[IFLA_CAN_DATA_BITTIMING]), sizeof(bt));
-		err = can_validate_bittiming(&bt, extack);
-		if (err)
-			return err;
+	/* 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 */
+	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));
 	}
 
+	can_set_default_mtu(dev);
+
 	return 0;
 }
 
-static int can_tdc_changelink(struct can_priv *priv, const struct nlattr *nla,
+static int can_tdc_changelink(struct data_bittiming_params *dbt_params,
+			      const struct nlattr *nla,
 			      struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb_tdc[IFLA_CAN_TDC_MAX + 1];
 	struct can_tdc tdc = { 0 };
-	const struct can_tdc_const *tdc_const = priv->fd.tdc_const;
+	const struct can_tdc_const *tdc_const = dbt_params->tdc_const;
 	int err;
 
-	if (!tdc_const || !can_fd_tdc_is_enabled(priv))
+	if (!tdc_const) {
+		NL_SET_ERR_MSG(extack, "The device does not support TDC");
 		return -EOPNOTSUPP;
+	}
 
 	err = nla_parse_nested(tb_tdc, IFLA_CAN_TDC_MAX, nla,
 			       can_tdc_policy, extack);
@@ -179,69 +308,107 @@ static int can_tdc_changelink(struct can_priv *priv, const struct nlattr *nla,
 		tdc.tdcf = tdcf;
 	}
 
-	priv->fd.tdc = tdc;
+	dbt_params->tdc = tdc;
 
 	return 0;
 }
 
-static int can_changelink(struct net_device *dev, struct nlattr *tb[],
-			  struct nlattr *data[],
-			  struct netlink_ext_ack *extack)
+static int can_dbt_changelink(struct net_device *dev, struct nlattr *data[],
+			      bool fd, struct netlink_ext_ack *extack)
 {
+	struct nlattr *data_bittiming, *data_tdc;
 	struct can_priv *priv = netdev_priv(dev);
-	bool fd_tdc_flag_provided = false;
+	struct data_bittiming_params *dbt_params;
+	struct can_bittiming dbt;
+	bool need_tdc_calc = false;
+	u32 tdc_mask;
 	int err;
 
-	/* We need synchronization with dev->stop() */
-	ASSERT_RTNL();
+	if (fd) {
+		data_bittiming = data[IFLA_CAN_DATA_BITTIMING];
+		data_tdc = data[IFLA_CAN_TDC];
+		dbt_params = &priv->fd;
+		tdc_mask = CAN_CTRLMODE_FD_TDC_MASK;
+	} else {
+		return -EOPNOTSUPP; /* Place holder for CAN XL */
+	}
 
-	if (data[IFLA_CAN_CTRLMODE]) {
-		struct can_ctrlmode *cm;
-		u32 ctrlstatic;
-		u32 maskedflags;
+	if (!data_bittiming)
+		return 0;
 
-		/* Do not allow changing controller mode while running */
-		if (dev->flags & IFF_UP)
-			return -EBUSY;
-		cm = nla_data(data[IFLA_CAN_CTRLMODE]);
-		ctrlstatic = can_get_static_ctrlmode(priv);
-		maskedflags = cm->flags & cm->mask;
+	/* Do not allow changing bittiming while running */
+	if (dev->flags & IFF_UP)
+		return -EBUSY;
 
-		/* check whether provided bits are allowed to be passed */
-		if (maskedflags & ~(priv->ctrlmode_supported | ctrlstatic))
-			return -EOPNOTSUPP;
+	/* 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 (!dbt_params->data_bittiming_const && !dbt_params->do_set_data_bittiming &&
+	    !dbt_params->data_bitrate_const)
+		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;
+	memcpy(&dbt, nla_data(data_bittiming), sizeof(dbt));
+	err = can_get_bittiming(dev, &dbt, dbt_params->data_bittiming_const,
+				dbt_params->data_bitrate_const,
+				dbt_params->data_bitrate_const_cnt, extack);
+	if (err)
+		return err;
 
-		/* make sure static options are provided by configuration */
-		if ((maskedflags & ctrlstatic) != ctrlstatic)
-			return -EOPNOTSUPP;
+	if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
+		NL_SET_ERR_MSG_FMT(extack,
+				   "CAN data bitrate %u bps surpasses transceiver capabilities of %u bps",
+				   dbt.bitrate, priv->bitrate_max);
+		return -EINVAL;
+	}
 
-		/* clear bits to be modified and copy the flag values */
-		priv->ctrlmode &= ~cm->mask;
-		priv->ctrlmode |= maskedflags;
+	memset(&dbt_params->tdc, 0, sizeof(dbt_params->tdc));
+	if (data[IFLA_CAN_CTRLMODE]) {
+		struct can_ctrlmode *cm = nla_data(data[IFLA_CAN_CTRLMODE]);
 
-		/* 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;
-			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));
+		need_tdc_calc = !(cm->mask & tdc_mask);
+	}
+	if (data_tdc) {
+		/* TDC parameters are provided: use them */
+		err = can_tdc_changelink(dbt_params, data_tdc, extack);
+		if (err) {
+			priv->ctrlmode &= ~tdc_mask;
+			return err;
 		}
-
-		fd_tdc_flag_provided = cm->mask & CAN_CTRLMODE_FD_TDC_MASK;
-		/* CAN_CTRLMODE_TDC_{AUTO,MANUAL} are mutually
-		 * exclusive: make sure to turn the other one off
+	} else if (need_tdc_calc) {
+		/* Neither of TDC parameters nor TDC flags are provided:
+		 * do calculation
 		 */
-		if (fd_tdc_flag_provided)
-			priv->ctrlmode &= cm->flags | ~CAN_CTRLMODE_FD_TDC_MASK;
+		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
+	   * turned off. TDC is disabled: do nothing
+	   */
+
+	memcpy(&dbt_params->data_bittiming, &dbt, sizeof(dbt));
+
+	if (dbt_params->do_set_data_bittiming) {
+		/* Finally, set the bit-timing registers */
+		err = dbt_params->do_set_data_bittiming(dev);
+		if (err)
+			return err;
 	}
 
+	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();
+
+	can_ctrlmode_changelink(dev, data, extack);
+
 	if (data[IFLA_CAN_BITTIMING]) {
 		struct can_bittiming bt;
 
@@ -312,75 +479,21 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 			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->fd.data_bittiming_const && !priv->fd.do_set_data_bittiming &&
-		    !priv->fd.data_bitrate_const)
-			return -EOPNOTSUPP;
-
-		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),
-		       sizeof(dbt));
-		err = can_get_bittiming(dev, &dbt,
-					priv->fd.data_bittiming_const,
-					priv->fd.data_bitrate_const,
-					priv->fd.data_bitrate_const_cnt,
-					extack);
-		if (err)
-			return err;
-
-		if (priv->bitrate_max && dbt.bitrate > priv->bitrate_max) {
-			NL_SET_ERR_MSG_FMT(extack,
-					   "CANFD data bitrate %u bps surpasses transceiver capabilities of %u bps",
-					   dbt.bitrate, priv->bitrate_max);
-			return -EINVAL;
-		}
-
-		memset(&priv->fd.tdc, 0, sizeof(priv->fd.tdc));
-		if (data[IFLA_CAN_TDC]) {
-			/* TDC parameters are provided: use them */
-			err = can_tdc_changelink(priv, data[IFLA_CAN_TDC],
-						 extack);
-			if (err) {
-				priv->ctrlmode &= ~CAN_CTRLMODE_FD_TDC_MASK;
-				return err;
-			}
-		} else if (!fd_tdc_flag_provided) {
-			/* Neither of TDC parameters nor TDC flags are
-			 * provided: do calculation
-			 */
-			can_calc_tdco(&priv->fd.tdc, priv->fd.tdc_const, &dbt,
-				      &priv->ctrlmode, priv->ctrlmode_supported);
-		} /* else: both CAN_CTRLMODE_TDC_{AUTO,MANUAL} are explicitly
-		   * turned off. TDC is disabled: do nothing
-		   */
-
-		memcpy(&priv->fd.data_bittiming, &dbt, sizeof(dbt));
-
-		if (priv->fd.do_set_data_bittiming) {
-			/* Finally, set the bit-timing registers */
-			err = priv->fd.do_set_data_bittiming(dev);
-			if (err)
-				return err;
-		}
-	}
+	/* CAN FD */
+	err = can_dbt_changelink(dev, data, true, 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;
 		unsigned int i;
 
-		if (!priv->do_set_termination)
+		if (!priv->do_set_termination) {
+			NL_SET_ERR_MSG(extack,
+				       "Termination is not configurable on this device");
 			return -EOPNOTSUPP;
+		}
 
 		/* check whether given value is supported by the interface */
 		for (i = 0; i < num_term; i++) {
@@ -401,38 +514,55 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 	return 0;
 }
 
-static size_t can_tdc_get_size(const struct net_device *dev)
+static size_t can_tdc_get_size(struct data_bittiming_params *dbt_params,
+			       u32 tdc_flags)
 {
-	struct can_priv *priv = netdev_priv(dev);
+	bool tdc_manual = tdc_flags & CAN_CTRLMODE_TDC_MANUAL_MASK;
 	size_t size;
 
-	if (!priv->fd.tdc_const)
+	if (!dbt_params->tdc_const)
 		return 0;
 
 	size = nla_total_size(0);			/* nest IFLA_CAN_TDC */
-	if (priv->ctrlmode_supported & CAN_CTRLMODE_TDC_MANUAL) {
+	if (tdc_manual) {
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV_MIN */
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV_MAX */
 	}
 	size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO_MIN */
 	size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO_MAX */
-	if (priv->fd.tdc_const->tdcf_max) {
+	if (dbt_params->tdc_const->tdcf_max) {
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF_MIN */
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF_MAX */
 	}
 
-	if (can_fd_tdc_is_enabled(priv)) {
-		if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL ||
-		    priv->fd.do_get_auto_tdcv)
+	if (tdc_flags) {
+		if (tdc_manual || dbt_params->do_get_auto_tdcv)
 			size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV */
 		size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO */
-		if (priv->fd.tdc_const->tdcf_max)
+		if (dbt_params->tdc_const->tdcf_max)
 			size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF */
 	}
 
 	return size;
 }
 
+static size_t can_data_bittiming_get_size(struct data_bittiming_params *dbt_params,
+					  u32 tdc_flags)
+{
+	size_t size = 0;
+
+	if (dbt_params->data_bittiming.bitrate)		/* IFLA_CAN_DATA_BITTIMING */
+		size += nla_total_size(sizeof(dbt_params->data_bittiming));
+	if (dbt_params->data_bittiming_const)		/* IFLA_CAN_DATA_BITTIMING_CONST */
+		size += nla_total_size(sizeof(*dbt_params->data_bittiming_const));
+	if (dbt_params->data_bitrate_const)		/* IFLA_CAN_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 */
+
+	return size;
+}
+
 static size_t can_ctrlmode_ext_get_size(void)
 {
 	return nla_total_size(0) +		/* nest IFLA_CAN_CTRLMODE_EXT */
@@ -454,10 +584,6 @@ static size_t can_get_size(const struct net_device *dev)
 	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->fd.data_bittiming.bitrate)			/* IFLA_CAN_DATA_BITTIMING */
-		size += nla_total_size(sizeof(struct can_bittiming));
-	if (priv->fd.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 */
@@ -466,31 +592,69 @@ static size_t can_get_size(const struct net_device *dev)
 	if (priv->bitrate_const)				/* IFLA_CAN_BITRATE_CONST */
 		size += nla_total_size(sizeof(*priv->bitrate_const) *
 				       priv->bitrate_const_cnt);
-	if (priv->fd.data_bitrate_const)			/* IFLA_CAN_DATA_BITRATE_CONST */
-		size += nla_total_size(sizeof(*priv->fd.data_bitrate_const) *
-				       priv->fd.data_bitrate_const_cnt);
 	size += sizeof(priv->bitrate_max);			/* IFLA_CAN_BITRATE_MAX */
-	size += can_tdc_get_size(dev);				/* IFLA_CAN_TDC */
 	size += can_ctrlmode_ext_get_size();			/* IFLA_CAN_CTRLMODE_EXT */
 
+	size += can_data_bittiming_get_size(&priv->fd,
+					    priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK);
+
 	return size;
 }
 
-static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev)
+static int can_bittiming_fill_info(struct sk_buff *skb, int ifla_can_bittiming,
+				   struct can_bittiming *bittiming)
+{
+	return bittiming->bitrate != CAN_BITRATE_UNSET &&
+		bittiming->bitrate != CAN_BITRATE_UNKNOWN &&
+		nla_put(skb, ifla_can_bittiming, sizeof(*bittiming), bittiming);
+}
+
+static int can_bittiming_const_fill_info(struct sk_buff *skb,
+					 int ifla_can_bittiming_const,
+					 const struct can_bittiming_const *bittiming_const)
+{
+	return bittiming_const &&
+		nla_put(skb, ifla_can_bittiming_const,
+			sizeof(*bittiming_const), bittiming_const);
+}
+
+static int can_bitrate_const_fill_info(struct sk_buff *skb,
+				       int ifla_can_bitrate_const,
+				       const u32 *bitrate_const, unsigned int cnt)
+{
+	return bitrate_const &&
+		nla_put(skb, ifla_can_bitrate_const,
+			sizeof(*bitrate_const) * cnt, bitrate_const);
+}
+
+static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev,
+			     int ifla_can_tdc)
 {
-	struct nlattr *nest;
 	struct can_priv *priv = netdev_priv(dev);
-	struct can_tdc *tdc = &priv->fd.tdc;
-	const struct can_tdc_const *tdc_const = priv->fd.tdc_const;
+	struct data_bittiming_params *dbt_params;
+	const struct can_tdc_const *tdc_const;
+	struct can_tdc *tdc;
+	struct nlattr *nest;
+	bool tdc_is_enabled, tdc_manual;
+
+	if (ifla_can_tdc == IFLA_CAN_TDC) {
+		dbt_params = &priv->fd;
+		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 */
+	}
+	tdc_const = dbt_params->tdc_const;
+	tdc = &dbt_params->tdc;
 
 	if (!tdc_const)
 		return 0;
 
-	nest = nla_nest_start(skb, IFLA_CAN_TDC);
+	nest = nla_nest_start(skb, ifla_can_tdc);
 	if (!nest)
 		return -EMSGSIZE;
 
-	if (priv->ctrlmode_supported & CAN_CTRLMODE_TDC_MANUAL &&
+	if (tdc_manual &&
 	    (nla_put_u32(skb, IFLA_CAN_TDC_TDCV_MIN, tdc_const->tdcv_min) ||
 	     nla_put_u32(skb, IFLA_CAN_TDC_TDCV_MAX, tdc_const->tdcv_max)))
 		goto err_cancel;
@@ -502,15 +666,15 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	     nla_put_u32(skb, IFLA_CAN_TDC_TDCF_MAX, tdc_const->tdcf_max)))
 		goto err_cancel;
 
-	if (can_fd_tdc_is_enabled(priv)) {
+	if (tdc_is_enabled) {
 		u32 tdcv;
 		int err = -EINVAL;
 
-		if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL) {
+		if (tdc_manual) {
 			tdcv = tdc->tdcv;
 			err = 0;
-		} else if (priv->fd.do_get_auto_tdcv) {
-			err = priv->fd.do_get_auto_tdcv(dev, &tdcv);
+		} else if (dbt_params->do_get_auto_tdcv) {
+			err = dbt_params->do_get_auto_tdcv(dev, &tdcv);
 		}
 		if (!err && nla_put_u32(skb, IFLA_CAN_TDC_TDCV, tdcv))
 			goto err_cancel;
@@ -558,14 +722,11 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	if (priv->do_get_state)
 		priv->do_get_state(dev, &state);
 
-	if ((priv->bittiming.bitrate != CAN_BITRATE_UNSET &&
-	     priv->bittiming.bitrate != CAN_BITRATE_UNKNOWN &&
-	     nla_put(skb, IFLA_CAN_BITTIMING,
-		     sizeof(priv->bittiming), &priv->bittiming)) ||
+	if (can_bittiming_fill_info(skb, IFLA_CAN_BITTIMING,
+				    &priv->bittiming) ||
 
-	    (priv->bittiming_const &&
-	     nla_put(skb, IFLA_CAN_BITTIMING_CONST,
-		     sizeof(*priv->bittiming_const), priv->bittiming_const)) ||
+	    can_bittiming_const_fill_info(skb, IFLA_CAN_BITTIMING_CONST,
+					  priv->bittiming_const) ||
 
 	    nla_put(skb, IFLA_CAN_CLOCK, sizeof(priv->clock), &priv->clock) ||
 	    nla_put_u32(skb, IFLA_CAN_STATE, state) ||
@@ -576,14 +737,11 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	     !priv->do_get_berr_counter(dev, &bec) &&
 	     nla_put(skb, IFLA_CAN_BERR_COUNTER, sizeof(bec), &bec)) ||
 
-	    (priv->fd.data_bittiming.bitrate &&
-	     nla_put(skb, IFLA_CAN_DATA_BITTIMING,
-		     sizeof(priv->fd.data_bittiming), &priv->fd.data_bittiming)) ||
+	    can_bittiming_fill_info(skb, IFLA_CAN_DATA_BITTIMING,
+				    &priv->fd.data_bittiming) ||
 
-	    (priv->fd.data_bittiming_const &&
-	     nla_put(skb, IFLA_CAN_DATA_BITTIMING_CONST,
-		     sizeof(*priv->fd.data_bittiming_const),
-		     priv->fd.data_bittiming_const)) ||
+	    can_bittiming_const_fill_info(skb, IFLA_CAN_DATA_BITTIMING_CONST,
+					  priv->fd.data_bittiming_const) ||
 
 	    (priv->termination_const &&
 	     (nla_put_u16(skb, IFLA_CAN_TERMINATION, priv->termination) ||
@@ -592,23 +750,19 @@ static int can_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		      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)) ||
+	    can_bitrate_const_fill_info(skb, IFLA_CAN_BITRATE_CONST,
+					priv->bitrate_const,
+					priv->bitrate_const_cnt) ||
 
-	    (priv->fd.data_bitrate_const &&
-	     nla_put(skb, IFLA_CAN_DATA_BITRATE_CONST,
-		     sizeof(*priv->fd.data_bitrate_const) *
-		     priv->fd.data_bitrate_const_cnt,
-		     priv->fd.data_bitrate_const)) ||
+	    can_bitrate_const_fill_info(skb, IFLA_CAN_DATA_BITRATE_CONST,
+					priv->fd.data_bitrate_const,
+					priv->fd.data_bitrate_const_cnt) ||
 
 	    (nla_put(skb, IFLA_CAN_BITRATE_MAX,
 		     sizeof(priv->bitrate_max),
 		     &priv->bitrate_max)) ||
 
-	    can_tdc_fill_info(skb, dev) ||
+	    can_tdc_fill_info(skb, dev, IFLA_CAN_TDC) ||
 
 	    can_ctrlmode_ext_fill_info(skb, priv)
 	    )