Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 512 insertions, 0 deletions

diff --git a/drivers/thunderbolt/retimer.c b/drivers/thunderbolt/retimer.c
new file mode 100644
index 000000000..56008eb91
--- /dev/null
+++ b/drivers/thunderbolt/retimer.c
@@ -0,0 +1,512 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt/USB4 retimer support.
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Authors: Kranthi Kuntala <kranthi.kuntala@intel.com>
+ *	    Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/pm_runtime.h>
+#include <linux/sched/signal.h>
+
+#include "sb_regs.h"
+#include "tb.h"
+
+#define TB_MAX_RETIMER_INDEX	6
+
+/**
+ * tb_retimer_nvm_read() - Read contents of retimer NVM
+ * @rt: Retimer device
+ * @address: NVM address (in bytes) to start reading
+ * @buf: Data read from NVM is stored here
+ * @size: Number of bytes to read
+ *
+ * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
+ * read was successful and negative errno in case of failure.
+ */
+int tb_retimer_nvm_read(struct tb_retimer *rt, unsigned int address, void *buf,
+			size_t size)
+{
+	return usb4_port_retimer_nvm_read(rt->port, rt->index, address, buf, size);
+}
+
+static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct tb_nvm *nvm = priv;
+	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
+	int ret;
+
+	pm_runtime_get_sync(&rt->dev);
+
+	if (!mutex_trylock(&rt->tb->lock)) {
+		ret = restart_syscall();
+		goto out;
+	}
+
+	ret = tb_retimer_nvm_read(rt, offset, val, bytes);
+	mutex_unlock(&rt->tb->lock);
+
+out:
+	pm_runtime_mark_last_busy(&rt->dev);
+	pm_runtime_put_autosuspend(&rt->dev);
+
+	return ret;
+}
+
+static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct tb_nvm *nvm = priv;
+	struct tb_retimer *rt = tb_to_retimer(nvm->dev);
+	int ret = 0;
+
+	if (!mutex_trylock(&rt->tb->lock))
+		return restart_syscall();
+
+	ret = tb_nvm_write_buf(nvm, offset, val, bytes);
+	mutex_unlock(&rt->tb->lock);
+
+	return ret;
+}
+
+static int tb_retimer_nvm_add(struct tb_retimer *rt)
+{
+	struct tb_nvm *nvm;
+	int ret;
+
+	nvm = tb_nvm_alloc(&rt->dev);
+	if (IS_ERR(nvm)) {
+		ret = PTR_ERR(nvm) == -EOPNOTSUPP ? 0 : PTR_ERR(nvm);
+		goto err_nvm;
+	}
+
+	ret = tb_nvm_read_version(nvm);
+	if (ret)
+		goto err_nvm;
+
+	ret = tb_nvm_add_active(nvm, nvm_read);
+	if (ret)
+		goto err_nvm;
+
+	ret = tb_nvm_add_non_active(nvm, nvm_write);
+	if (ret)
+		goto err_nvm;
+
+	rt->nvm = nvm;
+	return 0;
+
+err_nvm:
+	dev_dbg(&rt->dev, "NVM upgrade disabled\n");
+	if (!IS_ERR(nvm))
+		tb_nvm_free(nvm);
+
+	return ret;
+}
+
+static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
+{
+	unsigned int image_size;
+	const u8 *buf;
+	int ret;
+
+	ret = tb_nvm_validate(rt->nvm);
+	if (ret)
+		return ret;
+
+	buf = rt->nvm->buf_data_start;
+	image_size = rt->nvm->buf_data_size;
+
+	ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
+					 image_size);
+	if (ret)
+		return ret;
+
+	rt->nvm->flushed = true;
+	return 0;
+}
+
+static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only)
+{
+	u32 status;
+	int ret;
+
+	if (auth_only) {
+		ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0);
+		if (ret)
+			return ret;
+	}
+
+	ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
+	if (ret)
+		return ret;
+
+	usleep_range(100, 150);
+
+	/*
+	 * Check the status now if we still can access the retimer. It
+	 * is expected that the below fails.
+	 */
+	ret = usb4_port_retimer_nvm_authenticate_status(rt->port, rt->index,
+							&status);
+	if (!ret) {
+		rt->auth_status = status;
+		return status ? -EINVAL : 0;
+	}
+
+	return 0;
+}
+
+static ssize_t device_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+
+	return sysfs_emit(buf, "%#x\n", rt->device);
+}
+static DEVICE_ATTR_RO(device);
+
+static ssize_t nvm_authenticate_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+	int ret;
+
+	if (!mutex_trylock(&rt->tb->lock))
+		return restart_syscall();
+
+	if (!rt->nvm)
+		ret = -EAGAIN;
+	else if (rt->no_nvm_upgrade)
+		ret = -EOPNOTSUPP;
+	else
+		ret = sysfs_emit(buf, "%#x\n", rt->auth_status);
+
+	mutex_unlock(&rt->tb->lock);
+
+	return ret;
+}
+
+static ssize_t nvm_authenticate_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+	int val, ret;
+
+	pm_runtime_get_sync(&rt->dev);
+
+	if (!mutex_trylock(&rt->tb->lock)) {
+		ret = restart_syscall();
+		goto exit_rpm;
+	}
+
+	if (!rt->nvm) {
+		ret = -EAGAIN;
+		goto exit_unlock;
+	}
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		goto exit_unlock;
+
+	/* Always clear status */
+	rt->auth_status = 0;
+
+	if (val) {
+		if (val == AUTHENTICATE_ONLY) {
+			ret = tb_retimer_nvm_authenticate(rt, true);
+		} else {
+			if (!rt->nvm->flushed) {
+				if (!rt->nvm->buf) {
+					ret = -EINVAL;
+					goto exit_unlock;
+				}
+
+				ret = tb_retimer_nvm_validate_and_write(rt);
+				if (ret || val == WRITE_ONLY)
+					goto exit_unlock;
+			}
+			if (val == WRITE_AND_AUTHENTICATE)
+				ret = tb_retimer_nvm_authenticate(rt, false);
+		}
+	}
+
+exit_unlock:
+	mutex_unlock(&rt->tb->lock);
+exit_rpm:
+	pm_runtime_mark_last_busy(&rt->dev);
+	pm_runtime_put_autosuspend(&rt->dev);
+
+	if (ret)
+		return ret;
+	return count;
+}
+static DEVICE_ATTR_RW(nvm_authenticate);
+
+static ssize_t nvm_version_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+	int ret;
+
+	if (!mutex_trylock(&rt->tb->lock))
+		return restart_syscall();
+
+	if (!rt->nvm)
+		ret = -EAGAIN;
+	else
+		ret = sysfs_emit(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);
+
+	mutex_unlock(&rt->tb->lock);
+	return ret;
+}
+static DEVICE_ATTR_RO(nvm_version);
+
+static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+
+	return sysfs_emit(buf, "%#x\n", rt->vendor);
+}
+static DEVICE_ATTR_RO(vendor);
+
+static struct attribute *retimer_attrs[] = {
+	&dev_attr_device.attr,
+	&dev_attr_nvm_authenticate.attr,
+	&dev_attr_nvm_version.attr,
+	&dev_attr_vendor.attr,
+	NULL
+};
+
+static const struct attribute_group retimer_group = {
+	.attrs = retimer_attrs,
+};
+
+static const struct attribute_group *retimer_groups[] = {
+	&retimer_group,
+	NULL
+};
+
+static void tb_retimer_release(struct device *dev)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+
+	kfree(rt);
+}
+
+struct device_type tb_retimer_type = {
+	.name = "thunderbolt_retimer",
+	.groups = retimer_groups,
+	.release = tb_retimer_release,
+};
+
+static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status)
+{
+	struct tb_retimer *rt;
+	u32 vendor, device;
+	int ret;
+
+	ret = usb4_port_retimer_read(port, index, USB4_SB_VENDOR_ID, &vendor,
+				     sizeof(vendor));
+	if (ret) {
+		if (ret != -ENODEV)
+			tb_port_warn(port, "failed read retimer VendorId: %d\n", ret);
+		return ret;
+	}
+
+	ret = usb4_port_retimer_read(port, index, USB4_SB_PRODUCT_ID, &device,
+				     sizeof(device));
+	if (ret) {
+		if (ret != -ENODEV)
+			tb_port_warn(port, "failed read retimer ProductId: %d\n", ret);
+		return ret;
+	}
+
+	if (vendor != PCI_VENDOR_ID_INTEL && vendor != 0x8087) {
+		tb_port_info(port, "retimer NVM format of vendor %#x is not supported\n",
+			     vendor);
+		return -EOPNOTSUPP;
+	}
+
+	/*
+	 * Check that it supports NVM operations. If not then don't add
+	 * the device at all.
+	 */
+	ret = usb4_port_retimer_nvm_sector_size(port, index);
+	if (ret < 0)
+		return ret;
+
+	rt = kzalloc(sizeof(*rt), GFP_KERNEL);
+	if (!rt)
+		return -ENOMEM;
+
+	rt->index = index;
+	rt->vendor = vendor;
+	rt->device = device;
+	rt->auth_status = auth_status;
+	rt->port = port;
+	rt->tb = port->sw->tb;
+
+	rt->dev.parent = &port->usb4->dev;
+	rt->dev.bus = &tb_bus_type;
+	rt->dev.type = &tb_retimer_type;
+	dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev),
+		     port->port, index);
+
+	ret = device_register(&rt->dev);
+	if (ret) {
+		dev_err(&rt->dev, "failed to register retimer: %d\n", ret);
+		put_device(&rt->dev);
+		return ret;
+	}
+
+	ret = tb_retimer_nvm_add(rt);
+	if (ret) {
+		dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret);
+		device_unregister(&rt->dev);
+		return ret;
+	}
+
+	dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n",
+		 rt->vendor, rt->device);
+
+	pm_runtime_no_callbacks(&rt->dev);
+	pm_runtime_set_active(&rt->dev);
+	pm_runtime_enable(&rt->dev);
+	pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY);
+	pm_runtime_mark_last_busy(&rt->dev);
+	pm_runtime_use_autosuspend(&rt->dev);
+
+	return 0;
+}
+
+static void tb_retimer_remove(struct tb_retimer *rt)
+{
+	dev_info(&rt->dev, "retimer disconnected\n");
+	tb_nvm_free(rt->nvm);
+	device_unregister(&rt->dev);
+}
+
+struct tb_retimer_lookup {
+	const struct tb_port *port;
+	u8 index;
+};
+
+static int retimer_match(struct device *dev, void *data)
+{
+	const struct tb_retimer_lookup *lookup = data;
+	struct tb_retimer *rt = tb_to_retimer(dev);
+
+	return rt && rt->port == lookup->port && rt->index == lookup->index;
+}
+
+static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
+{
+	struct tb_retimer_lookup lookup = { .port = port, .index = index };
+	struct device *dev;
+
+	dev = device_find_child(&port->usb4->dev, &lookup, retimer_match);
+	if (dev)
+		return tb_to_retimer(dev);
+
+	return NULL;
+}
+
+/**
+ * tb_retimer_scan() - Scan for on-board retimers under port
+ * @port: USB4 port to scan
+ * @add: If true also registers found retimers
+ *
+ * Brings the sideband into a state where retimers can be accessed.
+ * Then Tries to enumerate on-board retimers connected to @port. Found
+ * retimers are registered as children of @port if @add is set.  Does
+ * not scan for cable retimers for now.
+ */
+int tb_retimer_scan(struct tb_port *port, bool add)
+{
+	u32 status[TB_MAX_RETIMER_INDEX + 1] = {};
+	int ret, i, last_idx = 0;
+
+	/*
+	 * Send broadcast RT to make sure retimer indices facing this
+	 * port are set.
+	 */
+	ret = usb4_port_enumerate_retimers(port);
+	if (ret)
+		return ret;
+
+	/*
+	 * Enable sideband channel for each retimer. We can do this
+	 * regardless whether there is device connected or not.
+	 */
+	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
+		usb4_port_retimer_set_inbound_sbtx(port, i);
+
+	/*
+	 * Before doing anything else, read the authentication status.
+	 * If the retimer has it set, store it for the new retimer
+	 * device instance.
+	 */
+	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
+		usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]);
+
+	for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
+		/*
+		 * Last retimer is true only for the last on-board
+		 * retimer (the one connected directly to the Type-C
+		 * port).
+		 */
+		ret = usb4_port_retimer_is_last(port, i);
+		if (ret > 0)
+			last_idx = i;
+		else if (ret < 0)
+			break;
+	}
+
+	if (!last_idx)
+		return 0;
+
+	/* Add on-board retimers if they do not exist already */
+	ret = 0;
+	for (i = 1; i <= last_idx; i++) {
+		struct tb_retimer *rt;
+
+		rt = tb_port_find_retimer(port, i);
+		if (rt) {
+			put_device(&rt->dev);
+		} else if (add) {
+			ret = tb_retimer_add(port, i, status[i]);
+			if (ret && ret != -EOPNOTSUPP)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static int remove_retimer(struct device *dev, void *data)
+{
+	struct tb_retimer *rt = tb_to_retimer(dev);
+	struct tb_port *port = data;
+
+	if (rt && rt->port == port)
+		tb_retimer_remove(rt);
+	return 0;
+}
+
+/**
+ * tb_retimer_remove_all() - Remove all retimers under port
+ * @port: USB4 port whose retimers to remove
+ *
+ * This removes all previously added retimers under @port.
+ */
+void tb_retimer_remove_all(struct tb_port *port)
+{
+	struct usb4_port *usb4;
+
+	usb4 = port->usb4;
+	if (usb4)
+		device_for_each_child_reverse(&usb4->dev, port,
+					      remove_retimer);
+}