Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3585 insertions, 0 deletions

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
new file mode 100644
index 0000000000..509b99af50
--- /dev/null
+++ b/drivers/thunderbolt/switch.c
@@ -0,0 +1,3585 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Thunderbolt driver - switch/port utility functions
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ * Copyright (C) 2018, Intel Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/pm_runtime.h>
+#include <linux/sched/signal.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/string_helpers.h>
+
+#include "tb.h"
+
+/* Switch NVM support */
+
+struct nvm_auth_status {
+	struct list_head list;
+	uuid_t uuid;
+	u32 status;
+};
+
+/*
+ * Hold NVM authentication failure status per switch This information
+ * needs to stay around even when the switch gets power cycled so we
+ * keep it separately.
+ */
+static LIST_HEAD(nvm_auth_status_cache);
+static DEFINE_MUTEX(nvm_auth_status_lock);
+
+static struct nvm_auth_status *__nvm_get_auth_status(const struct tb_switch *sw)
+{
+	struct nvm_auth_status *st;
+
+	list_for_each_entry(st, &nvm_auth_status_cache, list) {
+		if (uuid_equal(&st->uuid, sw->uuid))
+			return st;
+	}
+
+	return NULL;
+}
+
+static void nvm_get_auth_status(const struct tb_switch *sw, u32 *status)
+{
+	struct nvm_auth_status *st;
+
+	mutex_lock(&nvm_auth_status_lock);
+	st = __nvm_get_auth_status(sw);
+	mutex_unlock(&nvm_auth_status_lock);
+
+	*status = st ? st->status : 0;
+}
+
+static void nvm_set_auth_status(const struct tb_switch *sw, u32 status)
+{
+	struct nvm_auth_status *st;
+
+	if (WARN_ON(!sw->uuid))
+		return;
+
+	mutex_lock(&nvm_auth_status_lock);
+	st = __nvm_get_auth_status(sw);
+
+	if (!st) {
+		st = kzalloc(sizeof(*st), GFP_KERNEL);
+		if (!st)
+			goto unlock;
+
+		memcpy(&st->uuid, sw->uuid, sizeof(st->uuid));
+		INIT_LIST_HEAD(&st->list);
+		list_add_tail(&st->list, &nvm_auth_status_cache);
+	}
+
+	st->status = status;
+unlock:
+	mutex_unlock(&nvm_auth_status_lock);
+}
+
+static void nvm_clear_auth_status(const struct tb_switch *sw)
+{
+	struct nvm_auth_status *st;
+
+	mutex_lock(&nvm_auth_status_lock);
+	st = __nvm_get_auth_status(sw);
+	if (st) {
+		list_del(&st->list);
+		kfree(st);
+	}
+	mutex_unlock(&nvm_auth_status_lock);
+}
+
+static int nvm_validate_and_write(struct tb_switch *sw)
+{
+	unsigned int image_size;
+	const u8 *buf;
+	int ret;
+
+	ret = tb_nvm_validate(sw->nvm);
+	if (ret)
+		return ret;
+
+	ret = tb_nvm_write_headers(sw->nvm);
+	if (ret)
+		return ret;
+
+	buf = sw->nvm->buf_data_start;
+	image_size = sw->nvm->buf_data_size;
+
+	if (tb_switch_is_usb4(sw))
+		ret = usb4_switch_nvm_write(sw, 0, buf, image_size);
+	else
+		ret = dma_port_flash_write(sw->dma_port, 0, buf, image_size);
+	if (ret)
+		return ret;
+
+	sw->nvm->flushed = true;
+	return 0;
+}
+
+static int nvm_authenticate_host_dma_port(struct tb_switch *sw)
+{
+	int ret = 0;
+
+	/*
+	 * Root switch NVM upgrade requires that we disconnect the
+	 * existing paths first (in case it is not in safe mode
+	 * already).
+	 */
+	if (!sw->safe_mode) {
+		u32 status;
+
+		ret = tb_domain_disconnect_all_paths(sw->tb);
+		if (ret)
+			return ret;
+		/*
+		 * The host controller goes away pretty soon after this if
+		 * everything goes well so getting timeout is expected.
+		 */
+		ret = dma_port_flash_update_auth(sw->dma_port);
+		if (!ret || ret == -ETIMEDOUT)
+			return 0;
+
+		/*
+		 * Any error from update auth operation requires power
+		 * cycling of the host router.
+		 */
+		tb_sw_warn(sw, "failed to authenticate NVM, power cycling\n");
+		if (dma_port_flash_update_auth_status(sw->dma_port, &status) > 0)
+			nvm_set_auth_status(sw, status);
+	}
+
+	/*
+	 * From safe mode we can get out by just power cycling the
+	 * switch.
+	 */
+	dma_port_power_cycle(sw->dma_port);
+	return ret;
+}
+
+static int nvm_authenticate_device_dma_port(struct tb_switch *sw)
+{
+	int ret, retries = 10;
+
+	ret = dma_port_flash_update_auth(sw->dma_port);
+	switch (ret) {
+	case 0:
+	case -ETIMEDOUT:
+	case -EACCES:
+	case -EINVAL:
+		/* Power cycle is required */
+		break;
+	default:
+		return ret;
+	}
+
+	/*
+	 * Poll here for the authentication status. It takes some time
+	 * for the device to respond (we get timeout for a while). Once
+	 * we get response the device needs to be power cycled in order
+	 * to the new NVM to be taken into use.
+	 */
+	do {
+		u32 status;
+
+		ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
+		if (ret < 0 && ret != -ETIMEDOUT)
+			return ret;
+		if (ret > 0) {
+			if (status) {
+				tb_sw_warn(sw, "failed to authenticate NVM\n");
+				nvm_set_auth_status(sw, status);
+			}
+
+			tb_sw_info(sw, "power cycling the switch now\n");
+			dma_port_power_cycle(sw->dma_port);
+			return 0;
+		}
+
+		msleep(500);
+	} while (--retries);
+
+	return -ETIMEDOUT;
+}
+
+static void nvm_authenticate_start_dma_port(struct tb_switch *sw)
+{
+	struct pci_dev *root_port;
+
+	/*
+	 * During host router NVM upgrade we should not allow root port to
+	 * go into D3cold because some root ports cannot trigger PME
+	 * itself. To be on the safe side keep the root port in D0 during
+	 * the whole upgrade process.
+	 */
+	root_port = pcie_find_root_port(sw->tb->nhi->pdev);
+	if (root_port)
+		pm_runtime_get_noresume(&root_port->dev);
+}
+
+static void nvm_authenticate_complete_dma_port(struct tb_switch *sw)
+{
+	struct pci_dev *root_port;
+
+	root_port = pcie_find_root_port(sw->tb->nhi->pdev);
+	if (root_port)
+		pm_runtime_put(&root_port->dev);
+}
+
+static inline bool nvm_readable(struct tb_switch *sw)
+{
+	if (tb_switch_is_usb4(sw)) {
+		/*
+		 * USB4 devices must support NVM operations but it is
+		 * optional for hosts. Therefore we query the NVM sector
+		 * size here and if it is supported assume NVM
+		 * operations are implemented.
+		 */
+		return usb4_switch_nvm_sector_size(sw) > 0;
+	}
+
+	/* Thunderbolt 2 and 3 devices support NVM through DMA port */
+	return !!sw->dma_port;
+}
+
+static inline bool nvm_upgradeable(struct tb_switch *sw)
+{
+	if (sw->no_nvm_upgrade)
+		return false;
+	return nvm_readable(sw);
+}
+
+static int nvm_authenticate(struct tb_switch *sw, bool auth_only)
+{
+	int ret;
+
+	if (tb_switch_is_usb4(sw)) {
+		if (auth_only) {
+			ret = usb4_switch_nvm_set_offset(sw, 0);
+			if (ret)
+				return ret;
+		}
+		sw->nvm->authenticating = true;
+		return usb4_switch_nvm_authenticate(sw);
+	}
+	if (auth_only)
+		return -EOPNOTSUPP;
+
+	sw->nvm->authenticating = true;
+	if (!tb_route(sw)) {
+		nvm_authenticate_start_dma_port(sw);
+		ret = nvm_authenticate_host_dma_port(sw);
+	} else {
+		ret = nvm_authenticate_device_dma_port(sw);
+	}
+
+	return ret;
+}
+
+/**
+ * tb_switch_nvm_read() - Read router NVM
+ * @sw: Router whose NVM to read
+ * @address: Start address on the NVM
+ * @buf: Buffer where the read data is copied
+ * @size: Size of the buffer in bytes
+ *
+ * Reads from router NVM and returns the requested data in @buf. Locking
+ * is up to the caller. Returns %0 in success and negative errno in case
+ * of failure.
+ */
+int tb_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
+		       size_t size)
+{
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_nvm_read(sw, address, buf, size);
+	return dma_port_flash_read(sw->dma_port, address, buf, size);
+}
+
+static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct tb_nvm *nvm = priv;
+	struct tb_switch *sw = tb_to_switch(nvm->dev);
+	int ret;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (!mutex_trylock(&sw->tb->lock)) {
+		ret = restart_syscall();
+		goto out;
+	}
+
+	ret = tb_switch_nvm_read(sw, offset, val, bytes);
+	mutex_unlock(&sw->tb->lock);
+
+out:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+
+static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes)
+{
+	struct tb_nvm *nvm = priv;
+	struct tb_switch *sw = tb_to_switch(nvm->dev);
+	int ret;
+
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
+
+	/*
+	 * Since writing the NVM image might require some special steps,
+	 * for example when CSS headers are written, we cache the image
+	 * locally here and handle the special cases when the user asks
+	 * us to authenticate the image.
+	 */
+	ret = tb_nvm_write_buf(nvm, offset, val, bytes);
+	mutex_unlock(&sw->tb->lock);
+
+	return ret;
+}
+
+static int tb_switch_nvm_add(struct tb_switch *sw)
+{
+	struct tb_nvm *nvm;
+	int ret;
+
+	if (!nvm_readable(sw))
+		return 0;
+
+	nvm = tb_nvm_alloc(&sw->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;
+
+	/*
+	 * If the switch is in safe-mode the only accessible portion of
+	 * the NVM is the non-active one where userspace is expected to
+	 * write new functional NVM.
+	 */
+	if (!sw->safe_mode) {
+		ret = tb_nvm_add_active(nvm, nvm_read);
+		if (ret)
+			goto err_nvm;
+	}
+
+	if (!sw->no_nvm_upgrade) {
+		ret = tb_nvm_add_non_active(nvm, nvm_write);
+		if (ret)
+			goto err_nvm;
+	}
+
+	sw->nvm = nvm;
+	return 0;
+
+err_nvm:
+	tb_sw_dbg(sw, "NVM upgrade disabled\n");
+	sw->no_nvm_upgrade = true;
+	if (!IS_ERR(nvm))
+		tb_nvm_free(nvm);
+
+	return ret;
+}
+
+static void tb_switch_nvm_remove(struct tb_switch *sw)
+{
+	struct tb_nvm *nvm;
+
+	nvm = sw->nvm;
+	sw->nvm = NULL;
+
+	if (!nvm)
+		return;
+
+	/* Remove authentication status in case the switch is unplugged */
+	if (!nvm->authenticating)
+		nvm_clear_auth_status(sw);
+
+	tb_nvm_free(nvm);
+}
+
+/* port utility functions */
+
+static const char *tb_port_type(const struct tb_regs_port_header *port)
+{
+	switch (port->type >> 16) {
+	case 0:
+		switch ((u8) port->type) {
+		case 0:
+			return "Inactive";
+		case 1:
+			return "Port";
+		case 2:
+			return "NHI";
+		default:
+			return "unknown";
+		}
+	case 0x2:
+		return "Ethernet";
+	case 0x8:
+		return "SATA";
+	case 0xe:
+		return "DP/HDMI";
+	case 0x10:
+		return "PCIe";
+	case 0x20:
+		return "USB";
+	default:
+		return "unknown";
+	}
+}
+
+static void tb_dump_port(struct tb *tb, const struct tb_port *port)
+{
+	const struct tb_regs_port_header *regs = &port->config;
+
+	tb_dbg(tb,
+	       " Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
+	       regs->port_number, regs->vendor_id, regs->device_id,
+	       regs->revision, regs->thunderbolt_version, tb_port_type(regs),
+	       regs->type);
+	tb_dbg(tb, "  Max hop id (in/out): %d/%d\n",
+	       regs->max_in_hop_id, regs->max_out_hop_id);
+	tb_dbg(tb, "  Max counters: %d\n", regs->max_counters);
+	tb_dbg(tb, "  NFC Credits: %#x\n", regs->nfc_credits);
+	tb_dbg(tb, "  Credits (total/control): %u/%u\n", port->total_credits,
+	       port->ctl_credits);
+}
+
+/**
+ * tb_port_state() - get connectedness state of a port
+ * @port: the port to check
+ *
+ * The port must have a TB_CAP_PHY (i.e. it should be a real port).
+ *
+ * Return: Returns an enum tb_port_state on success or an error code on failure.
+ */
+int tb_port_state(struct tb_port *port)
+{
+	struct tb_cap_phy phy;
+	int res;
+	if (port->cap_phy == 0) {
+		tb_port_WARN(port, "does not have a PHY\n");
+		return -EINVAL;
+	}
+	res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
+	if (res)
+		return res;
+	return phy.state;
+}
+
+/**
+ * tb_wait_for_port() - wait for a port to become ready
+ * @port: Port to wait
+ * @wait_if_unplugged: Wait also when port is unplugged
+ *
+ * Wait up to 1 second for a port to reach state TB_PORT_UP. If
+ * wait_if_unplugged is set then we also wait if the port is in state
+ * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
+ * switch resume). Otherwise we only wait if a device is registered but the link
+ * has not yet been established.
+ *
+ * Return: Returns an error code on failure. Returns 0 if the port is not
+ * connected or failed to reach state TB_PORT_UP within one second. Returns 1
+ * if the port is connected and in state TB_PORT_UP.
+ */
+int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
+{
+	int retries = 10;
+	int state;
+	if (!port->cap_phy) {
+		tb_port_WARN(port, "does not have PHY\n");
+		return -EINVAL;
+	}
+	if (tb_is_upstream_port(port)) {
+		tb_port_WARN(port, "is the upstream port\n");
+		return -EINVAL;
+	}
+
+	while (retries--) {
+		state = tb_port_state(port);
+		switch (state) {
+		case TB_PORT_DISABLED:
+			tb_port_dbg(port, "is disabled (state: 0)\n");
+			return 0;
+
+		case TB_PORT_UNPLUGGED:
+			if (wait_if_unplugged) {
+				/* used during resume */
+				tb_port_dbg(port,
+					    "is unplugged (state: 7), retrying...\n");
+				msleep(100);
+				break;
+			}
+			tb_port_dbg(port, "is unplugged (state: 7)\n");
+			return 0;
+
+		case TB_PORT_UP:
+		case TB_PORT_TX_CL0S:
+		case TB_PORT_RX_CL0S:
+		case TB_PORT_CL1:
+		case TB_PORT_CL2:
+			tb_port_dbg(port, "is connected, link is up (state: %d)\n", state);
+			return 1;
+
+		default:
+			if (state < 0)
+				return state;
+
+			/*
+			 * After plug-in the state is TB_PORT_CONNECTING. Give it some
+			 * time.
+			 */
+			tb_port_dbg(port,
+				    "is connected, link is not up (state: %d), retrying...\n",
+				    state);
+			msleep(100);
+		}
+
+	}
+	tb_port_warn(port,
+		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
+	return 0;
+}
+
+/**
+ * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
+ * @port: Port to add/remove NFC credits
+ * @credits: Credits to add/remove
+ *
+ * Change the number of NFC credits allocated to @port by @credits. To remove
+ * NFC credits pass a negative amount of credits.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_port_add_nfc_credits(struct tb_port *port, int credits)
+{
+	u32 nfc_credits;
+
+	if (credits == 0 || port->sw->is_unplugged)
+		return 0;
+
+	/*
+	 * USB4 restricts programming NFC buffers to lane adapters only
+	 * so skip other ports.
+	 */
+	if (tb_switch_is_usb4(port->sw) && !tb_port_is_null(port))
+		return 0;
+
+	nfc_credits = port->config.nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK;
+	if (credits < 0)
+		credits = max_t(int, -nfc_credits, credits);
+
+	nfc_credits += credits;
+
+	tb_port_dbg(port, "adding %d NFC credits to %lu", credits,
+		    port->config.nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK);
+
+	port->config.nfc_credits &= ~ADP_CS_4_NFC_BUFFERS_MASK;
+	port->config.nfc_credits |= nfc_credits;
+
+	return tb_port_write(port, &port->config.nfc_credits,
+			     TB_CFG_PORT, ADP_CS_4, 1);
+}
+
+/**
+ * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
+ * @port: Port whose counters to clear
+ * @counter: Counter index to clear
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_port_clear_counter(struct tb_port *port, int counter)
+{
+	u32 zero[3] = { 0, 0, 0 };
+	tb_port_dbg(port, "clearing counter %d\n", counter);
+	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
+}
+
+/**
+ * tb_port_unlock() - Unlock downstream port
+ * @port: Port to unlock
+ *
+ * Needed for USB4 but can be called for any CIO/USB4 ports. Makes the
+ * downstream router accessible for CM.
+ */
+int tb_port_unlock(struct tb_port *port)
+{
+	if (tb_switch_is_icm(port->sw))
+		return 0;
+	if (!tb_port_is_null(port))
+		return -EINVAL;
+	if (tb_switch_is_usb4(port->sw))
+		return usb4_port_unlock(port);
+	return 0;
+}
+
+static int __tb_port_enable(struct tb_port *port, bool enable)
+{
+	int ret;
+	u32 phy;
+
+	if (!tb_port_is_null(port))
+		return -EINVAL;
+
+	ret = tb_port_read(port, &phy, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	if (enable)
+		phy &= ~LANE_ADP_CS_1_LD;
+	else
+		phy |= LANE_ADP_CS_1_LD;
+
+
+	ret = tb_port_write(port, &phy, TB_CFG_PORT,
+			    port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	tb_port_dbg(port, "lane %s\n", str_enabled_disabled(enable));
+	return 0;
+}
+
+/**
+ * tb_port_enable() - Enable lane adapter
+ * @port: Port to enable (can be %NULL)
+ *
+ * This is used for lane 0 and 1 adapters to enable it.
+ */
+int tb_port_enable(struct tb_port *port)
+{
+	return __tb_port_enable(port, true);
+}
+
+/**
+ * tb_port_disable() - Disable lane adapter
+ * @port: Port to disable (can be %NULL)
+ *
+ * This is used for lane 0 and 1 adapters to disable it.
+ */
+int tb_port_disable(struct tb_port *port)
+{
+	return __tb_port_enable(port, false);
+}
+
+/*
+ * tb_init_port() - initialize a port
+ *
+ * This is a helper method for tb_switch_alloc. Does not check or initialize
+ * any downstream switches.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_init_port(struct tb_port *port)
+{
+	int res;
+	int cap;
+
+	INIT_LIST_HEAD(&port->list);
+
+	/* Control adapter does not have configuration space */
+	if (!port->port)
+		return 0;
+
+	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
+	if (res) {
+		if (res == -ENODEV) {
+			tb_dbg(port->sw->tb, " Port %d: not implemented\n",
+			       port->port);
+			port->disabled = true;
+			return 0;
+		}
+		return res;
+	}
+
+	/* Port 0 is the switch itself and has no PHY. */
+	if (port->config.type == TB_TYPE_PORT) {
+		cap = tb_port_find_cap(port, TB_PORT_CAP_PHY);
+
+		if (cap > 0)
+			port->cap_phy = cap;
+		else
+			tb_port_WARN(port, "non switch port without a PHY\n");
+
+		cap = tb_port_find_cap(port, TB_PORT_CAP_USB4);
+		if (cap > 0)
+			port->cap_usb4 = cap;
+
+		/*
+		 * USB4 ports the buffers allocated for the control path
+		 * can be read from the path config space. Legacy
+		 * devices we use hard-coded value.
+		 */
+		if (port->cap_usb4) {
+			struct tb_regs_hop hop;
+
+			if (!tb_port_read(port, &hop, TB_CFG_HOPS, 0, 2))
+				port->ctl_credits = hop.initial_credits;
+		}
+		if (!port->ctl_credits)
+			port->ctl_credits = 2;
+
+	} else {
+		cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
+		if (cap > 0)
+			port->cap_adap = cap;
+	}
+
+	port->total_credits =
+		(port->config.nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
+		ADP_CS_4_TOTAL_BUFFERS_SHIFT;
+
+	tb_dump_port(port->sw->tb, port);
+	return 0;
+}
+
+static int tb_port_alloc_hopid(struct tb_port *port, bool in, int min_hopid,
+			       int max_hopid)
+{
+	int port_max_hopid;
+	struct ida *ida;
+
+	if (in) {
+		port_max_hopid = port->config.max_in_hop_id;
+		ida = &port->in_hopids;
+	} else {
+		port_max_hopid = port->config.max_out_hop_id;
+		ida = &port->out_hopids;
+	}
+
+	/*
+	 * NHI can use HopIDs 1-max for other adapters HopIDs 0-7 are
+	 * reserved.
+	 */
+	if (!tb_port_is_nhi(port) && min_hopid < TB_PATH_MIN_HOPID)
+		min_hopid = TB_PATH_MIN_HOPID;
+
+	if (max_hopid < 0 || max_hopid > port_max_hopid)
+		max_hopid = port_max_hopid;
+
+	return ida_simple_get(ida, min_hopid, max_hopid + 1, GFP_KERNEL);
+}
+
+/**
+ * tb_port_alloc_in_hopid() - Allocate input HopID from port
+ * @port: Port to allocate HopID for
+ * @min_hopid: Minimum acceptable input HopID
+ * @max_hopid: Maximum acceptable input HopID
+ *
+ * Return: HopID between @min_hopid and @max_hopid or negative errno in
+ * case of error.
+ */
+int tb_port_alloc_in_hopid(struct tb_port *port, int min_hopid, int max_hopid)
+{
+	return tb_port_alloc_hopid(port, true, min_hopid, max_hopid);
+}
+
+/**
+ * tb_port_alloc_out_hopid() - Allocate output HopID from port
+ * @port: Port to allocate HopID for
+ * @min_hopid: Minimum acceptable output HopID
+ * @max_hopid: Maximum acceptable output HopID
+ *
+ * Return: HopID between @min_hopid and @max_hopid or negative errno in
+ * case of error.
+ */
+int tb_port_alloc_out_hopid(struct tb_port *port, int min_hopid, int max_hopid)
+{
+	return tb_port_alloc_hopid(port, false, min_hopid, max_hopid);
+}
+
+/**
+ * tb_port_release_in_hopid() - Release allocated input HopID from port
+ * @port: Port whose HopID to release
+ * @hopid: HopID to release
+ */
+void tb_port_release_in_hopid(struct tb_port *port, int hopid)
+{
+	ida_simple_remove(&port->in_hopids, hopid);
+}
+
+/**
+ * tb_port_release_out_hopid() - Release allocated output HopID from port
+ * @port: Port whose HopID to release
+ * @hopid: HopID to release
+ */
+void tb_port_release_out_hopid(struct tb_port *port, int hopid)
+{
+	ida_simple_remove(&port->out_hopids, hopid);
+}
+
+static inline bool tb_switch_is_reachable(const struct tb_switch *parent,
+					  const struct tb_switch *sw)
+{
+	u64 mask = (1ULL << parent->config.depth * 8) - 1;
+	return (tb_route(parent) & mask) == (tb_route(sw) & mask);
+}
+
+/**
+ * tb_next_port_on_path() - Return next port for given port on a path
+ * @start: Start port of the walk
+ * @end: End port of the walk
+ * @prev: Previous port (%NULL if this is the first)
+ *
+ * This function can be used to walk from one port to another if they
+ * are connected through zero or more switches. If the @prev is dual
+ * link port, the function follows that link and returns another end on
+ * that same link.
+ *
+ * If the @end port has been reached, return %NULL.
+ *
+ * Domain tb->lock must be held when this function is called.
+ */
+struct tb_port *tb_next_port_on_path(struct tb_port *start, struct tb_port *end,
+				     struct tb_port *prev)
+{
+	struct tb_port *next;
+
+	if (!prev)
+		return start;
+
+	if (prev->sw == end->sw) {
+		if (prev == end)
+			return NULL;
+		return end;
+	}
+
+	if (tb_switch_is_reachable(prev->sw, end->sw)) {
+		next = tb_port_at(tb_route(end->sw), prev->sw);
+		/* Walk down the topology if next == prev */
+		if (prev->remote &&
+		    (next == prev || next->dual_link_port == prev))
+			next = prev->remote;
+	} else {
+		if (tb_is_upstream_port(prev)) {
+			next = prev->remote;
+		} else {
+			next = tb_upstream_port(prev->sw);
+			/*
+			 * Keep the same link if prev and next are both
+			 * dual link ports.
+			 */
+			if (next->dual_link_port &&
+			    next->link_nr != prev->link_nr) {
+				next = next->dual_link_port;
+			}
+		}
+	}
+
+	return next != prev ? next : NULL;
+}
+
+/**
+ * tb_port_get_link_speed() - Get current link speed
+ * @port: Port to check (USB4 or CIO)
+ *
+ * Returns link speed in Gb/s or negative errno in case of failure.
+ */
+int tb_port_get_link_speed(struct tb_port *port)
+{
+	u32 val, speed;
+	int ret;
+
+	if (!port->cap_phy)
+		return -EINVAL;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	speed = (val & LANE_ADP_CS_1_CURRENT_SPEED_MASK) >>
+		LANE_ADP_CS_1_CURRENT_SPEED_SHIFT;
+
+	switch (speed) {
+	case LANE_ADP_CS_1_CURRENT_SPEED_GEN4:
+		return 40;
+	case LANE_ADP_CS_1_CURRENT_SPEED_GEN3:
+		return 20;
+	default:
+		return 10;
+	}
+}
+
+/**
+ * tb_port_get_link_width() - Get current link width
+ * @port: Port to check (USB4 or CIO)
+ *
+ * Returns link width. Return the link width as encoded in &enum
+ * tb_link_width or negative errno in case of failure.
+ */
+int tb_port_get_link_width(struct tb_port *port)
+{
+	u32 val;
+	int ret;
+
+	if (!port->cap_phy)
+		return -EINVAL;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	/* Matches the values in enum tb_link_width */
+	return (val & LANE_ADP_CS_1_CURRENT_WIDTH_MASK) >>
+		LANE_ADP_CS_1_CURRENT_WIDTH_SHIFT;
+}
+
+static bool tb_port_is_width_supported(struct tb_port *port,
+				       unsigned int width_mask)
+{
+	u32 phy, widths;
+	int ret;
+
+	if (!port->cap_phy)
+		return false;
+
+	ret = tb_port_read(port, &phy, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_0, 1);
+	if (ret)
+		return false;
+
+	widths = (phy & LANE_ADP_CS_0_SUPPORTED_WIDTH_MASK) >>
+		LANE_ADP_CS_0_SUPPORTED_WIDTH_SHIFT;
+
+	return widths & width_mask;
+}
+
+static bool is_gen4_link(struct tb_port *port)
+{
+	return tb_port_get_link_speed(port) > 20;
+}
+
+/**
+ * tb_port_set_link_width() - Set target link width of the lane adapter
+ * @port: Lane adapter
+ * @width: Target link width
+ *
+ * Sets the target link width of the lane adapter to @width. Does not
+ * enable/disable lane bonding. For that call tb_port_set_lane_bonding().
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width)
+{
+	u32 val;
+	int ret;
+
+	if (!port->cap_phy)
+		return -EINVAL;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	val &= ~LANE_ADP_CS_1_TARGET_WIDTH_MASK;
+	switch (width) {
+	case TB_LINK_WIDTH_SINGLE:
+		/* Gen 4 link cannot be single */
+		if (is_gen4_link(port))
+			return -EOPNOTSUPP;
+		val |= LANE_ADP_CS_1_TARGET_WIDTH_SINGLE <<
+			LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
+		break;
+	case TB_LINK_WIDTH_DUAL:
+		val |= LANE_ADP_CS_1_TARGET_WIDTH_DUAL <<
+			LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_phy + LANE_ADP_CS_1, 1);
+}
+
+/**
+ * tb_port_set_lane_bonding() - Enable/disable lane bonding
+ * @port: Lane adapter
+ * @bonding: enable/disable bonding
+ *
+ * Enables or disables lane bonding. This should be called after target
+ * link width has been set (tb_port_set_link_width()). Note in most
+ * cases one should use tb_port_lane_bonding_enable() instead to enable
+ * lane bonding.
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+static int tb_port_set_lane_bonding(struct tb_port *port, bool bonding)
+{
+	u32 val;
+	int ret;
+
+	if (!port->cap_phy)
+		return -EINVAL;
+
+	ret = tb_port_read(port, &val, TB_CFG_PORT,
+			   port->cap_phy + LANE_ADP_CS_1, 1);
+	if (ret)
+		return ret;
+
+	if (bonding)
+		val |= LANE_ADP_CS_1_LB;
+	else
+		val &= ~LANE_ADP_CS_1_LB;
+
+	return tb_port_write(port, &val, TB_CFG_PORT,
+			     port->cap_phy + LANE_ADP_CS_1, 1);
+}
+
+/**
+ * tb_port_lane_bonding_enable() - Enable bonding on port
+ * @port: port to enable
+ *
+ * Enable bonding by setting the link width of the port and the other
+ * port in case of dual link port. Does not wait for the link to
+ * actually reach the bonded state so caller needs to call
+ * tb_port_wait_for_link_width() before enabling any paths through the
+ * link to make sure the link is in expected state.
+ *
+ * Return: %0 in case of success and negative errno in case of error
+ */
+int tb_port_lane_bonding_enable(struct tb_port *port)
+{
+	enum tb_link_width width;
+	int ret;
+
+	/*
+	 * Enable lane bonding for both links if not already enabled by
+	 * for example the boot firmware.
+	 */
+	width = tb_port_get_link_width(port);
+	if (width == TB_LINK_WIDTH_SINGLE) {
+		ret = tb_port_set_link_width(port, TB_LINK_WIDTH_DUAL);
+		if (ret)
+			goto err_lane0;
+	}
+
+	width = tb_port_get_link_width(port->dual_link_port);
+	if (width == TB_LINK_WIDTH_SINGLE) {
+		ret = tb_port_set_link_width(port->dual_link_port,
+					     TB_LINK_WIDTH_DUAL);
+		if (ret)
+			goto err_lane0;
+	}
+
+	/*
+	 * Only set bonding if the link was not already bonded. This
+	 * avoids the lane adapter to re-enter bonding state.
+	 */
+	if (width == TB_LINK_WIDTH_SINGLE && !tb_is_upstream_port(port)) {
+		ret = tb_port_set_lane_bonding(port, true);
+		if (ret)
+			goto err_lane1;
+	}
+
+	/*
+	 * When lane 0 bonding is set it will affect lane 1 too so
+	 * update both.
+	 */
+	port->bonded = true;
+	port->dual_link_port->bonded = true;
+
+	return 0;
+
+err_lane1:
+	tb_port_set_link_width(port->dual_link_port, TB_LINK_WIDTH_SINGLE);
+err_lane0:
+	tb_port_set_link_width(port, TB_LINK_WIDTH_SINGLE);
+
+	return ret;
+}
+
+/**
+ * tb_port_lane_bonding_disable() - Disable bonding on port
+ * @port: port to disable
+ *
+ * Disable bonding by setting the link width of the port and the
+ * other port in case of dual link port.
+ */
+void tb_port_lane_bonding_disable(struct tb_port *port)
+{
+	tb_port_set_lane_bonding(port, false);
+	tb_port_set_link_width(port->dual_link_port, TB_LINK_WIDTH_SINGLE);
+	tb_port_set_link_width(port, TB_LINK_WIDTH_SINGLE);
+	port->dual_link_port->bonded = false;
+	port->bonded = false;
+}
+
+/**
+ * tb_port_wait_for_link_width() - Wait until link reaches specific width
+ * @port: Port to wait for
+ * @width_mask: Expected link width mask
+ * @timeout_msec: Timeout in ms how long to wait
+ *
+ * Should be used after both ends of the link have been bonded (or
+ * bonding has been disabled) to wait until the link actually reaches
+ * the expected state. Returns %-ETIMEDOUT if the width was not reached
+ * within the given timeout, %0 if it did. Can be passed a mask of
+ * expected widths and succeeds if any of the widths is reached.
+ */
+int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
+				int timeout_msec)
+{
+	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+	int ret;
+
+	/* Gen 4 link does not support single lane */
+	if ((width_mask & TB_LINK_WIDTH_SINGLE) && is_gen4_link(port))
+		return -EOPNOTSUPP;
+
+	do {
+		ret = tb_port_get_link_width(port);
+		if (ret < 0) {
+			/*
+			 * Sometimes we get port locked error when
+			 * polling the lanes so we can ignore it and
+			 * retry.
+			 */
+			if (ret != -EACCES)
+				return ret;
+		} else if (ret & width_mask) {
+			return 0;
+		}
+
+		usleep_range(1000, 2000);
+	} while (ktime_before(ktime_get(), timeout));
+
+	return -ETIMEDOUT;
+}
+
+static int tb_port_do_update_credits(struct tb_port *port)
+{
+	u32 nfc_credits;
+	int ret;
+
+	ret = tb_port_read(port, &nfc_credits, TB_CFG_PORT, ADP_CS_4, 1);
+	if (ret)
+		return ret;
+
+	if (nfc_credits != port->config.nfc_credits) {
+		u32 total;
+
+		total = (nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
+			ADP_CS_4_TOTAL_BUFFERS_SHIFT;
+
+		tb_port_dbg(port, "total credits changed %u -> %u\n",
+			    port->total_credits, total);
+
+		port->config.nfc_credits = nfc_credits;
+		port->total_credits = total;
+	}
+
+	return 0;
+}
+
+/**
+ * tb_port_update_credits() - Re-read port total credits
+ * @port: Port to update
+ *
+ * After the link is bonded (or bonding was disabled) the port total
+ * credits may change, so this function needs to be called to re-read
+ * the credits. Updates also the second lane adapter.
+ */
+int tb_port_update_credits(struct tb_port *port)
+{
+	int ret;
+
+	ret = tb_port_do_update_credits(port);
+	if (ret)
+		return ret;
+	return tb_port_do_update_credits(port->dual_link_port);
+}
+
+static int tb_port_start_lane_initialization(struct tb_port *port)
+{
+	int ret;
+
+	if (tb_switch_is_usb4(port->sw))
+		return 0;
+
+	ret = tb_lc_start_lane_initialization(port);
+	return ret == -EINVAL ? 0 : ret;
+}
+
+/*
+ * Returns true if the port had something (router, XDomain) connected
+ * before suspend.
+ */
+static bool tb_port_resume(struct tb_port *port)
+{
+	bool has_remote = tb_port_has_remote(port);
+
+	if (port->usb4) {
+		usb4_port_device_resume(port->usb4);
+	} else if (!has_remote) {
+		/*
+		 * For disconnected downstream lane adapters start lane
+		 * initialization now so we detect future connects.
+		 *
+		 * For XDomain start the lane initialzation now so the
+		 * link gets re-established.
+		 *
+		 * This is only needed for non-USB4 ports.
+		 */
+		if (!tb_is_upstream_port(port) || port->xdomain)
+			tb_port_start_lane_initialization(port);
+	}
+
+	return has_remote || port->xdomain;
+}
+
+/**
+ * tb_port_is_enabled() - Is the adapter port enabled
+ * @port: Port to check
+ */
+bool tb_port_is_enabled(struct tb_port *port)
+{
+	switch (port->config.type) {
+	case TB_TYPE_PCIE_UP:
+	case TB_TYPE_PCIE_DOWN:
+		return tb_pci_port_is_enabled(port);
+
+	case TB_TYPE_DP_HDMI_IN:
+	case TB_TYPE_DP_HDMI_OUT:
+		return tb_dp_port_is_enabled(port);
+
+	case TB_TYPE_USB3_UP:
+	case TB_TYPE_USB3_DOWN:
+		return tb_usb3_port_is_enabled(port);
+
+	default:
+		return false;
+	}
+}
+
+/**
+ * tb_usb3_port_is_enabled() - Is the USB3 adapter port enabled
+ * @port: USB3 adapter port to check
+ */
+bool tb_usb3_port_is_enabled(struct tb_port *port)
+{
+	u32 data;
+
+	if (tb_port_read(port, &data, TB_CFG_PORT,
+			 port->cap_adap + ADP_USB3_CS_0, 1))
+		return false;
+
+	return !!(data & ADP_USB3_CS_0_PE);
+}
+
+/**
+ * tb_usb3_port_enable() - Enable USB3 adapter port
+ * @port: USB3 adapter port to enable
+ * @enable: Enable/disable the USB3 adapter
+ */
+int tb_usb3_port_enable(struct tb_port *port, bool enable)
+{
+	u32 word = enable ? (ADP_USB3_CS_0_PE | ADP_USB3_CS_0_V)
+			  : ADP_USB3_CS_0_V;
+
+	if (!port->cap_adap)
+		return -ENXIO;
+	return tb_port_write(port, &word, TB_CFG_PORT,
+			     port->cap_adap + ADP_USB3_CS_0, 1);
+}
+
+/**
+ * tb_pci_port_is_enabled() - Is the PCIe adapter port enabled
+ * @port: PCIe port to check
+ */
+bool tb_pci_port_is_enabled(struct tb_port *port)
+{
+	u32 data;
+
+	if (tb_port_read(port, &data, TB_CFG_PORT,
+			 port->cap_adap + ADP_PCIE_CS_0, 1))
+		return false;
+
+	return !!(data & ADP_PCIE_CS_0_PE);
+}
+
+/**
+ * tb_pci_port_enable() - Enable PCIe adapter port
+ * @port: PCIe port to enable
+ * @enable: Enable/disable the PCIe adapter
+ */
+int tb_pci_port_enable(struct tb_port *port, bool enable)
+{
+	u32 word = enable ? ADP_PCIE_CS_0_PE : 0x0;
+	if (!port->cap_adap)
+		return -ENXIO;
+	return tb_port_write(port, &word, TB_CFG_PORT,
+			     port->cap_adap + ADP_PCIE_CS_0, 1);
+}
+
+/**
+ * tb_dp_port_hpd_is_active() - Is HPD already active
+ * @port: DP out port to check
+ *
+ * Checks if the DP OUT adapter port has HDP bit already set.
+ */
+int tb_dp_port_hpd_is_active(struct tb_port *port)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_2, 1);
+	if (ret)
+		return ret;
+
+	return !!(data & ADP_DP_CS_2_HDP);
+}
+
+/**
+ * tb_dp_port_hpd_clear() - Clear HPD from DP IN port
+ * @port: Port to clear HPD
+ *
+ * If the DP IN port has HDP set, this function can be used to clear it.
+ */
+int tb_dp_port_hpd_clear(struct tb_port *port)
+{
+	u32 data;
+	int ret;
+
+	ret = tb_port_read(port, &data, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_3, 1);
+	if (ret)
+		return ret;
+
+	data |= ADP_DP_CS_3_HDPC;
+	return tb_port_write(port, &data, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_3, 1);
+}
+
+/**
+ * tb_dp_port_set_hops() - Set video/aux Hop IDs for DP port
+ * @port: DP IN/OUT port to set hops
+ * @video: Video Hop ID
+ * @aux_tx: AUX TX Hop ID
+ * @aux_rx: AUX RX Hop ID
+ *
+ * Programs specified Hop IDs for DP IN/OUT port. Can be called for USB4
+ * router DP adapters too but does not program the values as the fields
+ * are read-only.
+ */
+int tb_dp_port_set_hops(struct tb_port *port, unsigned int video,
+			unsigned int aux_tx, unsigned int aux_rx)
+{
+	u32 data[2];
+	int ret;
+
+	if (tb_switch_is_usb4(port->sw))
+		return 0;
+
+	ret = tb_port_read(port, data, TB_CFG_PORT,
+			   port->cap_adap + ADP_DP_CS_0, ARRAY_SIZE(data));
+	if (ret)
+		return ret;
+
+	data[0] &= ~ADP_DP_CS_0_VIDEO_HOPID_MASK;
+	data[1] &= ~ADP_DP_CS_1_AUX_RX_HOPID_MASK;
+	data[1] &= ~ADP_DP_CS_1_AUX_RX_HOPID_MASK;
+
+	data[0] |= (video << ADP_DP_CS_0_VIDEO_HOPID_SHIFT) &
+		ADP_DP_CS_0_VIDEO_HOPID_MASK;
+	data[1] |= aux_tx & ADP_DP_CS_1_AUX_TX_HOPID_MASK;
+	data[1] |= (aux_rx << ADP_DP_CS_1_AUX_RX_HOPID_SHIFT) &
+		ADP_DP_CS_1_AUX_RX_HOPID_MASK;
+
+	return tb_port_write(port, data, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_0, ARRAY_SIZE(data));
+}
+
+/**
+ * tb_dp_port_is_enabled() - Is DP adapter port enabled
+ * @port: DP adapter port to check
+ */
+bool tb_dp_port_is_enabled(struct tb_port *port)
+{
+	u32 data[2];
+
+	if (tb_port_read(port, data, TB_CFG_PORT, port->cap_adap + ADP_DP_CS_0,
+			 ARRAY_SIZE(data)))
+		return false;
+
+	return !!(data[0] & (ADP_DP_CS_0_VE | ADP_DP_CS_0_AE));
+}
+
+/**
+ * tb_dp_port_enable() - Enables/disables DP paths of a port
+ * @port: DP IN/OUT port
+ * @enable: Enable/disable DP path
+ *
+ * Once Hop IDs are programmed DP paths can be enabled or disabled by
+ * calling this function.
+ */
+int tb_dp_port_enable(struct tb_port *port, bool enable)
+{
+	u32 data[2];
+	int ret;
+
+	ret = tb_port_read(port, data, TB_CFG_PORT,
+			  port->cap_adap + ADP_DP_CS_0, ARRAY_SIZE(data));
+	if (ret)
+		return ret;
+
+	if (enable)
+		data[0] |= ADP_DP_CS_0_VE | ADP_DP_CS_0_AE;
+	else
+		data[0] &= ~(ADP_DP_CS_0_VE | ADP_DP_CS_0_AE);
+
+	return tb_port_write(port, data, TB_CFG_PORT,
+			     port->cap_adap + ADP_DP_CS_0, ARRAY_SIZE(data));
+}
+
+/* switch utility functions */
+
+static const char *tb_switch_generation_name(const struct tb_switch *sw)
+{
+	switch (sw->generation) {
+	case 1:
+		return "Thunderbolt 1";
+	case 2:
+		return "Thunderbolt 2";
+	case 3:
+		return "Thunderbolt 3";
+	case 4:
+		return "USB4";
+	default:
+		return "Unknown";
+	}
+}
+
+static void tb_dump_switch(const struct tb *tb, const struct tb_switch *sw)
+{
+	const struct tb_regs_switch_header *regs = &sw->config;
+
+	tb_dbg(tb, " %s Switch: %x:%x (Revision: %d, TB Version: %d)\n",
+	       tb_switch_generation_name(sw), regs->vendor_id, regs->device_id,
+	       regs->revision, regs->thunderbolt_version);
+	tb_dbg(tb, "  Max Port Number: %d\n", regs->max_port_number);
+	tb_dbg(tb, "  Config:\n");
+	tb_dbg(tb,
+		"   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
+	       regs->upstream_port_number, regs->depth,
+	       (((u64) regs->route_hi) << 32) | regs->route_lo,
+	       regs->enabled, regs->plug_events_delay);
+	tb_dbg(tb, "   unknown1: %#x unknown4: %#x\n",
+	       regs->__unknown1, regs->__unknown4);
+}
+
+/**
+ * tb_switch_reset() - reconfigure route, enable and send TB_CFG_PKG_RESET
+ * @sw: Switch to reset
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_switch_reset(struct tb_switch *sw)
+{
+	struct tb_cfg_result res;
+
+	if (sw->generation > 1)
+		return 0;
+
+	tb_sw_dbg(sw, "resetting switch\n");
+
+	res.err = tb_sw_write(sw, ((u32 *) &sw->config) + 2,
+			      TB_CFG_SWITCH, 2, 2);
+	if (res.err)
+		return res.err;
+	res = tb_cfg_reset(sw->tb->ctl, tb_route(sw));
+	if (res.err > 0)
+		return -EIO;
+	return res.err;
+}
+
+/**
+ * tb_switch_wait_for_bit() - Wait for specified value of bits in offset
+ * @sw: Router to read the offset value from
+ * @offset: Offset in the router config space to read from
+ * @bit: Bit mask in the offset to wait for
+ * @value: Value of the bits to wait for
+ * @timeout_msec: Timeout in ms how long to wait
+ *
+ * Wait till the specified bits in specified offset reach specified value.
+ * Returns %0 in case of success, %-ETIMEDOUT if the @value was not reached
+ * within the given timeout or a negative errno in case of failure.
+ */
+int tb_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
+			   u32 value, int timeout_msec)
+{
+	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
+
+	do {
+		u32 val;
+		int ret;
+
+		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
+		if (ret)
+			return ret;
+
+		if ((val & bit) == value)
+			return 0;
+
+		usleep_range(50, 100);
+	} while (ktime_before(ktime_get(), timeout));
+
+	return -ETIMEDOUT;
+}
+
+/*
+ * tb_plug_events_active() - enable/disable plug events on a switch
+ *
+ * Also configures a sane plug_events_delay of 255ms.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_plug_events_active(struct tb_switch *sw, bool active)
+{
+	u32 data;
+	int res;
+
+	if (tb_switch_is_icm(sw) || tb_switch_is_usb4(sw))
+		return 0;
+
+	sw->config.plug_events_delay = 0xff;
+	res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
+	if (res)
+		return res;
+
+	res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
+	if (res)
+		return res;
+
+	if (active) {
+		data = data & 0xFFFFFF83;
+		switch (sw->config.device_id) {
+		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
+		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
+		case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
+			break;
+		default:
+			/*
+			 * Skip Alpine Ridge, it needs to have vendor
+			 * specific USB hotplug event enabled for the
+			 * internal xHCI to work.
+			 */
+			if (!tb_switch_is_alpine_ridge(sw))
+				data |= TB_PLUG_EVENTS_USB_DISABLE;
+		}
+	} else {
+		data = data | 0x7c;
+	}
+	return tb_sw_write(sw, &data, TB_CFG_SWITCH,
+			   sw->cap_plug_events + 1, 1);
+}
+
+static ssize_t authorized_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%u\n", sw->authorized);
+}
+
+static int disapprove_switch(struct device *dev, void *not_used)
+{
+	char *envp[] = { "AUTHORIZED=0", NULL };
+	struct tb_switch *sw;
+
+	sw = tb_to_switch(dev);
+	if (sw && sw->authorized) {
+		int ret;
+
+		/* First children */
+		ret = device_for_each_child_reverse(&sw->dev, NULL, disapprove_switch);
+		if (ret)
+			return ret;
+
+		ret = tb_domain_disapprove_switch(sw->tb, sw);
+		if (ret)
+			return ret;
+
+		sw->authorized = 0;
+		kobject_uevent_env(&sw->dev.kobj, KOBJ_CHANGE, envp);
+	}
+
+	return 0;
+}
+
+static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
+{
+	char envp_string[13];
+	int ret = -EINVAL;
+	char *envp[] = { envp_string, NULL };
+
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
+
+	if (!!sw->authorized == !!val)
+		goto unlock;
+
+	switch (val) {
+	/* Disapprove switch */
+	case 0:
+		if (tb_route(sw)) {
+			ret = disapprove_switch(&sw->dev, NULL);
+			goto unlock;
+		}
+		break;
+
+	/* Approve switch */
+	case 1:
+		if (sw->key)
+			ret = tb_domain_approve_switch_key(sw->tb, sw);
+		else
+			ret = tb_domain_approve_switch(sw->tb, sw);
+		break;
+
+	/* Challenge switch */
+	case 2:
+		if (sw->key)
+			ret = tb_domain_challenge_switch_key(sw->tb, sw);
+		break;
+
+	default:
+		break;
+	}
+
+	if (!ret) {
+		sw->authorized = val;
+		/*
+		 * Notify status change to the userspace, informing the new
+		 * value of /sys/bus/thunderbolt/devices/.../authorized.
+		 */
+		sprintf(envp_string, "AUTHORIZED=%u", sw->authorized);
+		kobject_uevent_env(&sw->dev.kobj, KOBJ_CHANGE, envp);
+	}
+
+unlock:
+	mutex_unlock(&sw->tb->lock);
+	return ret;
+}
+
+static ssize_t authorized_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	unsigned int val;
+	ssize_t ret;
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret)
+		return ret;
+	if (val > 2)
+		return -EINVAL;
+
+	pm_runtime_get_sync(&sw->dev);
+	ret = tb_switch_set_authorized(sw, val);
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret ? ret : count;
+}
+static DEVICE_ATTR_RW(authorized);
+
+static ssize_t boot_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%u\n", sw->boot);
+}
+static DEVICE_ATTR_RO(boot);
+
+static ssize_t device_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%#x\n", sw->device);
+}
+static DEVICE_ATTR_RO(device);
+
+static ssize_t
+device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%s\n", sw->device_name ?: "");
+}
+static DEVICE_ATTR_RO(device_name);
+
+static ssize_t
+generation_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%u\n", sw->generation);
+}
+static DEVICE_ATTR_RO(generation);
+
+static ssize_t key_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	ssize_t ret;
+
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
+
+	if (sw->key)
+		ret = sysfs_emit(buf, "%*phN\n", TB_SWITCH_KEY_SIZE, sw->key);
+	else
+		ret = sysfs_emit(buf, "\n");
+
+	mutex_unlock(&sw->tb->lock);
+	return ret;
+}
+
+static ssize_t key_store(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	u8 key[TB_SWITCH_KEY_SIZE];
+	ssize_t ret = count;
+	bool clear = false;
+
+	if (!strcmp(buf, "\n"))
+		clear = true;
+	else if (hex2bin(key, buf, sizeof(key)))
+		return -EINVAL;
+
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
+
+	if (sw->authorized) {
+		ret = -EBUSY;
+	} else {
+		kfree(sw->key);
+		if (clear) {
+			sw->key = NULL;
+		} else {
+			sw->key = kmemdup(key, sizeof(key), GFP_KERNEL);
+			if (!sw->key)
+				ret = -ENOMEM;
+		}
+	}
+
+	mutex_unlock(&sw->tb->lock);
+	return ret;
+}
+static DEVICE_ATTR(key, 0600, key_show, key_store);
+
+static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%u.0 Gb/s\n", sw->link_speed);
+}
+
+/*
+ * Currently all lanes must run at the same speed but we expose here
+ * both directions to allow possible asymmetric links in the future.
+ */
+static DEVICE_ATTR(rx_speed, 0444, speed_show, NULL);
+static DEVICE_ATTR(tx_speed, 0444, speed_show, NULL);
+
+static ssize_t rx_lanes_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	unsigned int width;
+
+	switch (sw->link_width) {
+	case TB_LINK_WIDTH_SINGLE:
+	case TB_LINK_WIDTH_ASYM_TX:
+		width = 1;
+		break;
+	case TB_LINK_WIDTH_DUAL:
+		width = 2;
+		break;
+	case TB_LINK_WIDTH_ASYM_RX:
+		width = 3;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%u\n", width);
+}
+static DEVICE_ATTR(rx_lanes, 0444, rx_lanes_show, NULL);
+
+static ssize_t tx_lanes_show(struct device *dev, struct device_attribute *attr,
+			     char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	unsigned int width;
+
+	switch (sw->link_width) {
+	case TB_LINK_WIDTH_SINGLE:
+	case TB_LINK_WIDTH_ASYM_RX:
+		width = 1;
+		break;
+	case TB_LINK_WIDTH_DUAL:
+		width = 2;
+		break;
+	case TB_LINK_WIDTH_ASYM_TX:
+		width = 3;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return -EINVAL;
+	}
+
+	return sysfs_emit(buf, "%u\n", width);
+}
+static DEVICE_ATTR(tx_lanes, 0444, tx_lanes_show, NULL);
+
+static ssize_t nvm_authenticate_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	u32 status;
+
+	nvm_get_auth_status(sw, &status);
+	return sysfs_emit(buf, "%#x\n", status);
+}
+
+static ssize_t nvm_authenticate_sysfs(struct device *dev, const char *buf,
+				      bool disconnect)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	int val, ret;
+
+	pm_runtime_get_sync(&sw->dev);
+
+	if (!mutex_trylock(&sw->tb->lock)) {
+		ret = restart_syscall();
+		goto exit_rpm;
+	}
+
+	if (sw->no_nvm_upgrade) {
+		ret = -EOPNOTSUPP;
+		goto exit_unlock;
+	}
+
+	/* If NVMem devices are not yet added */
+	if (!sw->nvm) {
+		ret = -EAGAIN;
+		goto exit_unlock;
+	}
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		goto exit_unlock;
+
+	/* Always clear the authentication status */
+	nvm_clear_auth_status(sw);
+
+	if (val > 0) {
+		if (val == AUTHENTICATE_ONLY) {
+			if (disconnect)
+				ret = -EINVAL;
+			else
+				ret = nvm_authenticate(sw, true);
+		} else {
+			if (!sw->nvm->flushed) {
+				if (!sw->nvm->buf) {
+					ret = -EINVAL;
+					goto exit_unlock;
+				}
+
+				ret = nvm_validate_and_write(sw);
+				if (ret || val == WRITE_ONLY)
+					goto exit_unlock;
+			}
+			if (val == WRITE_AND_AUTHENTICATE) {
+				if (disconnect)
+					ret = tb_lc_force_power(sw);
+				else
+					ret = nvm_authenticate(sw, false);
+			}
+		}
+	}
+
+exit_unlock:
+	mutex_unlock(&sw->tb->lock);
+exit_rpm:
+	pm_runtime_mark_last_busy(&sw->dev);
+	pm_runtime_put_autosuspend(&sw->dev);
+
+	return ret;
+}
+
+static ssize_t nvm_authenticate_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	int ret = nvm_authenticate_sysfs(dev, buf, false);
+	if (ret)
+		return ret;
+	return count;
+}
+static DEVICE_ATTR_RW(nvm_authenticate);
+
+static ssize_t nvm_authenticate_on_disconnect_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	return nvm_authenticate_show(dev, attr, buf);
+}
+
+static ssize_t nvm_authenticate_on_disconnect_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	int ret;
+
+	ret = nvm_authenticate_sysfs(dev, buf, true);
+	return ret ? ret : count;
+}
+static DEVICE_ATTR_RW(nvm_authenticate_on_disconnect);
+
+static ssize_t nvm_version_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	int ret;
+
+	if (!mutex_trylock(&sw->tb->lock))
+		return restart_syscall();
+
+	if (sw->safe_mode)
+		ret = -ENODATA;
+	else if (!sw->nvm)
+		ret = -EAGAIN;
+	else
+		ret = sysfs_emit(buf, "%x.%x\n", sw->nvm->major, sw->nvm->minor);
+
+	mutex_unlock(&sw->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_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%#x\n", sw->vendor);
+}
+static DEVICE_ATTR_RO(vendor);
+
+static ssize_t
+vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%s\n", sw->vendor_name ?: "");
+}
+static DEVICE_ATTR_RO(vendor_name);
+
+static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	return sysfs_emit(buf, "%pUb\n", sw->uuid);
+}
+static DEVICE_ATTR_RO(unique_id);
+
+static struct attribute *switch_attrs[] = {
+	&dev_attr_authorized.attr,
+	&dev_attr_boot.attr,
+	&dev_attr_device.attr,
+	&dev_attr_device_name.attr,
+	&dev_attr_generation.attr,
+	&dev_attr_key.attr,
+	&dev_attr_nvm_authenticate.attr,
+	&dev_attr_nvm_authenticate_on_disconnect.attr,
+	&dev_attr_nvm_version.attr,
+	&dev_attr_rx_speed.attr,
+	&dev_attr_rx_lanes.attr,
+	&dev_attr_tx_speed.attr,
+	&dev_attr_tx_lanes.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_vendor_name.attr,
+	&dev_attr_unique_id.attr,
+	NULL,
+};
+
+static umode_t switch_attr_is_visible(struct kobject *kobj,
+				      struct attribute *attr, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct tb_switch *sw = tb_to_switch(dev);
+
+	if (attr == &dev_attr_authorized.attr) {
+		if (sw->tb->security_level == TB_SECURITY_NOPCIE ||
+		    sw->tb->security_level == TB_SECURITY_DPONLY)
+			return 0;
+	} else if (attr == &dev_attr_device.attr) {
+		if (!sw->device)
+			return 0;
+	} else if (attr == &dev_attr_device_name.attr) {
+		if (!sw->device_name)
+			return 0;
+	} else if (attr == &dev_attr_vendor.attr)  {
+		if (!sw->vendor)
+			return 0;
+	} else if (attr == &dev_attr_vendor_name.attr)  {
+		if (!sw->vendor_name)
+			return 0;
+	} else if (attr == &dev_attr_key.attr) {
+		if (tb_route(sw) &&
+		    sw->tb->security_level == TB_SECURITY_SECURE &&
+		    sw->security_level == TB_SECURITY_SECURE)
+			return attr->mode;
+		return 0;
+	} else if (attr == &dev_attr_rx_speed.attr ||
+		   attr == &dev_attr_rx_lanes.attr ||
+		   attr == &dev_attr_tx_speed.attr ||
+		   attr == &dev_attr_tx_lanes.attr) {
+		if (tb_route(sw))
+			return attr->mode;
+		return 0;
+	} else if (attr == &dev_attr_nvm_authenticate.attr) {
+		if (nvm_upgradeable(sw))
+			return attr->mode;
+		return 0;
+	} else if (attr == &dev_attr_nvm_version.attr) {
+		if (nvm_readable(sw))
+			return attr->mode;
+		return 0;
+	} else if (attr == &dev_attr_boot.attr) {
+		if (tb_route(sw))
+			return attr->mode;
+		return 0;
+	} else if (attr == &dev_attr_nvm_authenticate_on_disconnect.attr) {
+		if (sw->quirks & QUIRK_FORCE_POWER_LINK_CONTROLLER)
+			return attr->mode;
+		return 0;
+	}
+
+	return sw->safe_mode ? 0 : attr->mode;
+}
+
+static const struct attribute_group switch_group = {
+	.is_visible = switch_attr_is_visible,
+	.attrs = switch_attrs,
+};
+
+static const struct attribute_group *switch_groups[] = {
+	&switch_group,
+	NULL,
+};
+
+static void tb_switch_release(struct device *dev)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	struct tb_port *port;
+
+	dma_port_free(sw->dma_port);
+
+	tb_switch_for_each_port(sw, port) {
+		ida_destroy(&port->in_hopids);
+		ida_destroy(&port->out_hopids);
+	}
+
+	kfree(sw->uuid);
+	kfree(sw->device_name);
+	kfree(sw->vendor_name);
+	kfree(sw->ports);
+	kfree(sw->drom);
+	kfree(sw->key);
+	kfree(sw);
+}
+
+static int tb_switch_uevent(const struct device *dev, struct kobj_uevent_env *env)
+{
+	const struct tb_switch *sw = tb_to_switch(dev);
+	const char *type;
+
+	if (tb_switch_is_usb4(sw)) {
+		if (add_uevent_var(env, "USB4_VERSION=%u.0",
+				   usb4_switch_version(sw)))
+			return -ENOMEM;
+	}
+
+	if (!tb_route(sw)) {
+		type = "host";
+	} else {
+		const struct tb_port *port;
+		bool hub = false;
+
+		/* Device is hub if it has any downstream ports */
+		tb_switch_for_each_port(sw, port) {
+			if (!port->disabled && !tb_is_upstream_port(port) &&
+			     tb_port_is_null(port)) {
+				hub = true;
+				break;
+			}
+		}
+
+		type = hub ? "hub" : "device";
+	}
+
+	if (add_uevent_var(env, "USB4_TYPE=%s", type))
+		return -ENOMEM;
+	return 0;
+}
+
+/*
+ * Currently only need to provide the callbacks. Everything else is handled
+ * in the connection manager.
+ */
+static int __maybe_unused tb_switch_runtime_suspend(struct device *dev)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
+
+	if (cm_ops->runtime_suspend_switch)
+		return cm_ops->runtime_suspend_switch(sw);
+
+	return 0;
+}
+
+static int __maybe_unused tb_switch_runtime_resume(struct device *dev)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
+
+	if (cm_ops->runtime_resume_switch)
+		return cm_ops->runtime_resume_switch(sw);
+	return 0;
+}
+
+static const struct dev_pm_ops tb_switch_pm_ops = {
+	SET_RUNTIME_PM_OPS(tb_switch_runtime_suspend, tb_switch_runtime_resume,
+			   NULL)
+};
+
+struct device_type tb_switch_type = {
+	.name = "thunderbolt_device",
+	.release = tb_switch_release,
+	.uevent = tb_switch_uevent,
+	.pm = &tb_switch_pm_ops,
+};
+
+static int tb_switch_get_generation(struct tb_switch *sw)
+{
+	if (tb_switch_is_usb4(sw))
+		return 4;
+
+	if (sw->config.vendor_id == PCI_VENDOR_ID_INTEL) {
+		switch (sw->config.device_id) {
+		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
+		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
+		case PCI_DEVICE_ID_INTEL_LIGHT_PEAK:
+		case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_2C:
+		case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
+		case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
+		case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_4C_BRIDGE:
+			return 1;
+
+		case PCI_DEVICE_ID_INTEL_WIN_RIDGE_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE:
+			return 2;
+
+		case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_DD_BRIDGE:
+		case PCI_DEVICE_ID_INTEL_ICL_NHI0:
+		case PCI_DEVICE_ID_INTEL_ICL_NHI1:
+			return 3;
+		}
+	}
+
+	/*
+	 * For unknown switches assume generation to be 1 to be on the
+	 * safe side.
+	 */
+	tb_sw_warn(sw, "unsupported switch device id %#x\n",
+		   sw->config.device_id);
+	return 1;
+}
+
+static bool tb_switch_exceeds_max_depth(const struct tb_switch *sw, int depth)
+{
+	int max_depth;
+
+	if (tb_switch_is_usb4(sw) ||
+	    (sw->tb->root_switch && tb_switch_is_usb4(sw->tb->root_switch)))
+		max_depth = USB4_SWITCH_MAX_DEPTH;
+	else
+		max_depth = TB_SWITCH_MAX_DEPTH;
+
+	return depth > max_depth;
+}
+
+/**
+ * tb_switch_alloc() - allocate a switch
+ * @tb: Pointer to the owning domain
+ * @parent: Parent device for this switch
+ * @route: Route string for this switch
+ *
+ * Allocates and initializes a switch. Will not upload configuration to
+ * the switch. For that you need to call tb_switch_configure()
+ * separately. The returned switch should be released by calling
+ * tb_switch_put().
+ *
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of
+ * failure.
+ */
+struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
+				  u64 route)
+{
+	struct tb_switch *sw;
+	int upstream_port;
+	int i, ret, depth;
+
+	/* Unlock the downstream port so we can access the switch below */
+	if (route) {
+		struct tb_switch *parent_sw = tb_to_switch(parent);
+		struct tb_port *down;
+
+		down = tb_port_at(route, parent_sw);
+		tb_port_unlock(down);
+	}
+
+	depth = tb_route_length(route);
+
+	upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
+	if (upstream_port < 0)
+		return ERR_PTR(upstream_port);
+
+	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
+	if (!sw)
+		return ERR_PTR(-ENOMEM);
+
+	sw->tb = tb;
+	ret = tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5);
+	if (ret)
+		goto err_free_sw_ports;
+
+	sw->generation = tb_switch_get_generation(sw);
+
+	tb_dbg(tb, "current switch config:\n");
+	tb_dump_switch(tb, sw);
+
+	/* configure switch */
+	sw->config.upstream_port_number = upstream_port;
+	sw->config.depth = depth;
+	sw->config.route_hi = upper_32_bits(route);
+	sw->config.route_lo = lower_32_bits(route);
+	sw->config.enabled = 0;
+
+	/* Make sure we do not exceed maximum topology limit */
+	if (tb_switch_exceeds_max_depth(sw, depth)) {
+		ret = -EADDRNOTAVAIL;
+		goto err_free_sw_ports;
+	}
+
+	/* initialize ports */
+	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
+				GFP_KERNEL);
+	if (!sw->ports) {
+		ret = -ENOMEM;
+		goto err_free_sw_ports;
+	}
+
+	for (i = 0; i <= sw->config.max_port_number; i++) {
+		/* minimum setup for tb_find_cap and tb_drom_read to work */
+		sw->ports[i].sw = sw;
+		sw->ports[i].port = i;
+
+		/* Control port does not need HopID allocation */
+		if (i) {
+			ida_init(&sw->ports[i].in_hopids);
+			ida_init(&sw->ports[i].out_hopids);
+		}
+	}
+
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
+	if (ret > 0)
+		sw->cap_plug_events = ret;
+
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_TIME2);
+	if (ret > 0)
+		sw->cap_vsec_tmu = ret;
+
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
+	if (ret > 0)
+		sw->cap_lc = ret;
+
+	ret = tb_switch_find_vse_cap(sw, TB_VSE_CAP_CP_LP);
+	if (ret > 0)
+		sw->cap_lp = ret;
+
+	/* Root switch is always authorized */
+	if (!route)
+		sw->authorized = true;
+
+	device_initialize(&sw->dev);
+	sw->dev.parent = parent;
+	sw->dev.bus = &tb_bus_type;
+	sw->dev.type = &tb_switch_type;
+	sw->dev.groups = switch_groups;
+	dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
+
+	return sw;
+
+err_free_sw_ports:
+	kfree(sw->ports);
+	kfree(sw);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * tb_switch_alloc_safe_mode() - allocate a switch that is in safe mode
+ * @tb: Pointer to the owning domain
+ * @parent: Parent device for this switch
+ * @route: Route string for this switch
+ *
+ * This creates a switch in safe mode. This means the switch pretty much
+ * lacks all capabilities except DMA configuration port before it is
+ * flashed with a valid NVM firmware.
+ *
+ * The returned switch must be released by calling tb_switch_put().
+ *
+ * Return: Pointer to the allocated switch or ERR_PTR() in case of failure
+ */
+struct tb_switch *
+tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
+{
+	struct tb_switch *sw;
+
+	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
+	if (!sw)
+		return ERR_PTR(-ENOMEM);
+
+	sw->tb = tb;
+	sw->config.depth = tb_route_length(route);
+	sw->config.route_hi = upper_32_bits(route);
+	sw->config.route_lo = lower_32_bits(route);
+	sw->safe_mode = true;
+
+	device_initialize(&sw->dev);
+	sw->dev.parent = parent;
+	sw->dev.bus = &tb_bus_type;
+	sw->dev.type = &tb_switch_type;
+	sw->dev.groups = switch_groups;
+	dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
+
+	return sw;
+}
+
+/**
+ * tb_switch_configure() - Uploads configuration to the switch
+ * @sw: Switch to configure
+ *
+ * Call this function before the switch is added to the system. It will
+ * upload configuration to the switch and makes it available for the
+ * connection manager to use. Can be called to the switch again after
+ * resume from low power states to re-initialize it.
+ *
+ * Return: %0 in case of success and negative errno in case of failure
+ */
+int tb_switch_configure(struct tb_switch *sw)
+{
+	struct tb *tb = sw->tb;
+	u64 route;
+	int ret;
+
+	route = tb_route(sw);
+
+	tb_dbg(tb, "%s Switch at %#llx (depth: %d, up port: %d)\n",
+	       sw->config.enabled ? "restoring" : "initializing", route,
+	       tb_route_length(route), sw->config.upstream_port_number);
+
+	sw->config.enabled = 1;
+
+	if (tb_switch_is_usb4(sw)) {
+		/*
+		 * For USB4 devices, we need to program the CM version
+		 * accordingly so that it knows to expose all the
+		 * additional capabilities. Program it according to USB4
+		 * version to avoid changing existing (v1) routers behaviour.
+		 */
+		if (usb4_switch_version(sw) < 2)
+			sw->config.cmuv = ROUTER_CS_4_CMUV_V1;
+		else
+			sw->config.cmuv = ROUTER_CS_4_CMUV_V2;
+		sw->config.plug_events_delay = 0xa;
+
+		/* Enumerate the switch */
+		ret = tb_sw_write(sw, (u32 *)&sw->config + 1, TB_CFG_SWITCH,
+				  ROUTER_CS_1, 4);
+		if (ret)
+			return ret;
+
+		ret = usb4_switch_setup(sw);
+	} else {
+		if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
+			tb_sw_warn(sw, "unknown switch vendor id %#x\n",
+				   sw->config.vendor_id);
+
+		if (!sw->cap_plug_events) {
+			tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
+			return -ENODEV;
+		}
+
+		/* Enumerate the switch */
+		ret = tb_sw_write(sw, (u32 *)&sw->config + 1, TB_CFG_SWITCH,
+				  ROUTER_CS_1, 3);
+	}
+	if (ret)
+		return ret;
+
+	return tb_plug_events_active(sw, true);
+}
+
+/**
+ * tb_switch_configuration_valid() - Set the tunneling configuration to be valid
+ * @sw: Router to configure
+ *
+ * Needs to be called before any tunnels can be setup through the
+ * router. Can be called to any router.
+ *
+ * Returns %0 in success and negative errno otherwise.
+ */
+int tb_switch_configuration_valid(struct tb_switch *sw)
+{
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_configuration_valid(sw);
+	return 0;
+}
+
+static int tb_switch_set_uuid(struct tb_switch *sw)
+{
+	bool uid = false;
+	u32 uuid[4];
+	int ret;
+
+	if (sw->uuid)
+		return 0;
+
+	if (tb_switch_is_usb4(sw)) {
+		ret = usb4_switch_read_uid(sw, &sw->uid);
+		if (ret)
+			return ret;
+		uid = true;
+	} else {
+		/*
+		 * The newer controllers include fused UUID as part of
+		 * link controller specific registers
+		 */
+		ret = tb_lc_read_uuid(sw, uuid);
+		if (ret) {
+			if (ret != -EINVAL)
+				return ret;
+			uid = true;
+		}
+	}
+
+	if (uid) {
+		/*
+		 * ICM generates UUID based on UID and fills the upper
+		 * two words with ones. This is not strictly following
+		 * UUID format but we want to be compatible with it so
+		 * we do the same here.
+		 */
+		uuid[0] = sw->uid & 0xffffffff;
+		uuid[1] = (sw->uid >> 32) & 0xffffffff;
+		uuid[2] = 0xffffffff;
+		uuid[3] = 0xffffffff;
+	}
+
+	sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
+	if (!sw->uuid)
+		return -ENOMEM;
+	return 0;
+}
+
+static int tb_switch_add_dma_port(struct tb_switch *sw)
+{
+	u32 status;
+	int ret;
+
+	switch (sw->generation) {
+	case 2:
+		/* Only root switch can be upgraded */
+		if (tb_route(sw))
+			return 0;
+
+		fallthrough;
+	case 3:
+	case 4:
+		ret = tb_switch_set_uuid(sw);
+		if (ret)
+			return ret;
+		break;
+
+	default:
+		/*
+		 * DMA port is the only thing available when the switch
+		 * is in safe mode.
+		 */
+		if (!sw->safe_mode)
+			return 0;
+		break;
+	}
+
+	if (sw->no_nvm_upgrade)
+		return 0;
+
+	if (tb_switch_is_usb4(sw)) {
+		ret = usb4_switch_nvm_authenticate_status(sw, &status);
+		if (ret)
+			return ret;
+
+		if (status) {
+			tb_sw_info(sw, "switch flash authentication failed\n");
+			nvm_set_auth_status(sw, status);
+		}
+
+		return 0;
+	}
+
+	/* Root switch DMA port requires running firmware */
+	if (!tb_route(sw) && !tb_switch_is_icm(sw))
+		return 0;
+
+	sw->dma_port = dma_port_alloc(sw);
+	if (!sw->dma_port)
+		return 0;
+
+	/*
+	 * If there is status already set then authentication failed
+	 * when the dma_port_flash_update_auth() returned. Power cycling
+	 * is not needed (it was done already) so only thing we do here
+	 * is to unblock runtime PM of the root port.
+	 */
+	nvm_get_auth_status(sw, &status);
+	if (status) {
+		if (!tb_route(sw))
+			nvm_authenticate_complete_dma_port(sw);
+		return 0;
+	}
+
+	/*
+	 * Check status of the previous flash authentication. If there
+	 * is one we need to power cycle the switch in any case to make
+	 * it functional again.
+	 */
+	ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
+	if (ret <= 0)
+		return ret;
+
+	/* Now we can allow root port to suspend again */
+	if (!tb_route(sw))
+		nvm_authenticate_complete_dma_port(sw);
+
+	if (status) {
+		tb_sw_info(sw, "switch flash authentication failed\n");
+		nvm_set_auth_status(sw, status);
+	}
+
+	tb_sw_info(sw, "power cycling the switch now\n");
+	dma_port_power_cycle(sw->dma_port);
+
+	/*
+	 * We return error here which causes the switch adding failure.
+	 * It should appear back after power cycle is complete.
+	 */
+	return -ESHUTDOWN;
+}
+
+static void tb_switch_default_link_ports(struct tb_switch *sw)
+{
+	int i;
+
+	for (i = 1; i <= sw->config.max_port_number; i++) {
+		struct tb_port *port = &sw->ports[i];
+		struct tb_port *subordinate;
+
+		if (!tb_port_is_null(port))
+			continue;
+
+		/* Check for the subordinate port */
+		if (i == sw->config.max_port_number ||
+		    !tb_port_is_null(&sw->ports[i + 1]))
+			continue;
+
+		/* Link them if not already done so (by DROM) */
+		subordinate = &sw->ports[i + 1];
+		if (!port->dual_link_port && !subordinate->dual_link_port) {
+			port->link_nr = 0;
+			port->dual_link_port = subordinate;
+			subordinate->link_nr = 1;
+			subordinate->dual_link_port = port;
+
+			tb_sw_dbg(sw, "linked ports %d <-> %d\n",
+				  port->port, subordinate->port);
+		}
+	}
+}
+
+static bool tb_switch_lane_bonding_possible(struct tb_switch *sw)
+{
+	const struct tb_port *up = tb_upstream_port(sw);
+
+	if (!up->dual_link_port || !up->dual_link_port->remote)
+		return false;
+
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_lane_bonding_possible(sw);
+	return tb_lc_lane_bonding_possible(sw);
+}
+
+static int tb_switch_update_link_attributes(struct tb_switch *sw)
+{
+	struct tb_port *up;
+	bool change = false;
+	int ret;
+
+	if (!tb_route(sw) || tb_switch_is_icm(sw))
+		return 0;
+
+	up = tb_upstream_port(sw);
+
+	ret = tb_port_get_link_speed(up);
+	if (ret < 0)
+		return ret;
+	if (sw->link_speed != ret)
+		change = true;
+	sw->link_speed = ret;
+
+	ret = tb_port_get_link_width(up);
+	if (ret < 0)
+		return ret;
+	if (sw->link_width != ret)
+		change = true;
+	sw->link_width = ret;
+
+	/* Notify userspace that there is possible link attribute change */
+	if (device_is_registered(&sw->dev) && change)
+		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);
+
+	return 0;
+}
+
+/**
+ * tb_switch_lane_bonding_enable() - Enable lane bonding
+ * @sw: Switch to enable lane bonding
+ *
+ * Connection manager can call this function to enable lane bonding of a
+ * switch. If conditions are correct and both switches support the feature,
+ * lanes are bonded. It is safe to call this to any switch.
+ */
+int tb_switch_lane_bonding_enable(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	u64 route = tb_route(sw);
+	unsigned int width_mask;
+	int ret;
+
+	if (!route)
+		return 0;
+
+	if (!tb_switch_lane_bonding_possible(sw))
+		return 0;
+
+	up = tb_upstream_port(sw);
+	down = tb_switch_downstream_port(sw);
+
+	if (!tb_port_is_width_supported(up, TB_LINK_WIDTH_DUAL) ||
+	    !tb_port_is_width_supported(down, TB_LINK_WIDTH_DUAL))
+		return 0;
+
+	/*
+	 * Both lanes need to be in CL0. Here we assume lane 0 already be in
+	 * CL0 and check just for lane 1.
+	 */
+	if (tb_wait_for_port(down->dual_link_port, false) <= 0)
+		return -ENOTCONN;
+
+	ret = tb_port_lane_bonding_enable(up);
+	if (ret) {
+		tb_port_warn(up, "failed to enable lane bonding\n");
+		return ret;
+	}
+
+	ret = tb_port_lane_bonding_enable(down);
+	if (ret) {
+		tb_port_warn(down, "failed to enable lane bonding\n");
+		tb_port_lane_bonding_disable(up);
+		return ret;
+	}
+
+	/* Any of the widths are all bonded */
+	width_mask = TB_LINK_WIDTH_DUAL | TB_LINK_WIDTH_ASYM_TX |
+		     TB_LINK_WIDTH_ASYM_RX;
+
+	ret = tb_port_wait_for_link_width(down, width_mask, 100);
+	if (ret) {
+		tb_port_warn(down, "timeout enabling lane bonding\n");
+		return ret;
+	}
+
+	tb_port_update_credits(down);
+	tb_port_update_credits(up);
+	tb_switch_update_link_attributes(sw);
+
+	tb_sw_dbg(sw, "lane bonding enabled\n");
+	return ret;
+}
+
+/**
+ * tb_switch_lane_bonding_disable() - Disable lane bonding
+ * @sw: Switch whose lane bonding to disable
+ *
+ * Disables lane bonding between @sw and parent. This can be called even
+ * if lanes were not bonded originally.
+ */
+void tb_switch_lane_bonding_disable(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	int ret;
+
+	if (!tb_route(sw))
+		return;
+
+	up = tb_upstream_port(sw);
+	if (!up->bonded)
+		return;
+
+	down = tb_switch_downstream_port(sw);
+
+	tb_port_lane_bonding_disable(up);
+	tb_port_lane_bonding_disable(down);
+
+	/*
+	 * It is fine if we get other errors as the router might have
+	 * been unplugged.
+	 */
+	ret = tb_port_wait_for_link_width(down, TB_LINK_WIDTH_SINGLE, 100);
+	if (ret == -ETIMEDOUT)
+		tb_sw_warn(sw, "timeout disabling lane bonding\n");
+
+	tb_port_update_credits(down);
+	tb_port_update_credits(up);
+	tb_switch_update_link_attributes(sw);
+
+	tb_sw_dbg(sw, "lane bonding disabled\n");
+}
+
+/**
+ * tb_switch_configure_link() - Set link configured
+ * @sw: Switch whose link is configured
+ *
+ * Sets the link upstream from @sw configured (from both ends) so that
+ * it will not be disconnected when the domain exits sleep. Can be
+ * called for any switch.
+ *
+ * It is recommended that this is called after lane bonding is enabled.
+ *
+ * Returns %0 on success and negative errno in case of error.
+ */
+int tb_switch_configure_link(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+	int ret;
+
+	if (!tb_route(sw) || tb_switch_is_icm(sw))
+		return 0;
+
+	up = tb_upstream_port(sw);
+	if (tb_switch_is_usb4(up->sw))
+		ret = usb4_port_configure(up);
+	else
+		ret = tb_lc_configure_port(up);
+	if (ret)
+		return ret;
+
+	down = up->remote;
+	if (tb_switch_is_usb4(down->sw))
+		return usb4_port_configure(down);
+	return tb_lc_configure_port(down);
+}
+
+/**
+ * tb_switch_unconfigure_link() - Unconfigure link
+ * @sw: Switch whose link is unconfigured
+ *
+ * Sets the link unconfigured so the @sw will be disconnected if the
+ * domain exists sleep.
+ */
+void tb_switch_unconfigure_link(struct tb_switch *sw)
+{
+	struct tb_port *up, *down;
+
+	if (sw->is_unplugged)
+		return;
+	if (!tb_route(sw) || tb_switch_is_icm(sw))
+		return;
+
+	up = tb_upstream_port(sw);
+	if (tb_switch_is_usb4(up->sw))
+		usb4_port_unconfigure(up);
+	else
+		tb_lc_unconfigure_port(up);
+
+	down = up->remote;
+	if (tb_switch_is_usb4(down->sw))
+		usb4_port_unconfigure(down);
+	else
+		tb_lc_unconfigure_port(down);
+}
+
+static void tb_switch_credits_init(struct tb_switch *sw)
+{
+	if (tb_switch_is_icm(sw))
+		return;
+	if (!tb_switch_is_usb4(sw))
+		return;
+	if (usb4_switch_credits_init(sw))
+		tb_sw_info(sw, "failed to determine preferred buffer allocation, using defaults\n");
+}
+
+static int tb_switch_port_hotplug_enable(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	if (tb_switch_is_icm(sw))
+		return 0;
+
+	tb_switch_for_each_port(sw, port) {
+		int res;
+
+		if (!port->cap_usb4)
+			continue;
+
+		res = usb4_port_hotplug_enable(port);
+		if (res)
+			return res;
+	}
+	return 0;
+}
+
+/**
+ * tb_switch_add() - Add a switch to the domain
+ * @sw: Switch to add
+ *
+ * This is the last step in adding switch to the domain. It will read
+ * identification information from DROM and initializes ports so that
+ * they can be used to connect other switches. The switch will be
+ * exposed to the userspace when this function successfully returns. To
+ * remove and release the switch, call tb_switch_remove().
+ *
+ * Return: %0 in case of success and negative errno in case of failure
+ */
+int tb_switch_add(struct tb_switch *sw)
+{
+	int i, ret;
+
+	/*
+	 * Initialize DMA control port now before we read DROM. Recent
+	 * host controllers have more complete DROM on NVM that includes
+	 * vendor and model identification strings which we then expose
+	 * to the userspace. NVM can be accessed through DMA
+	 * configuration based mailbox.
+	 */
+	ret = tb_switch_add_dma_port(sw);
+	if (ret) {
+		dev_err(&sw->dev, "failed to add DMA port\n");
+		return ret;
+	}
+
+	if (!sw->safe_mode) {
+		tb_switch_credits_init(sw);
+
+		/* read drom */
+		ret = tb_drom_read(sw);
+		if (ret)
+			dev_warn(&sw->dev, "reading DROM failed: %d\n", ret);
+		tb_sw_dbg(sw, "uid: %#llx\n", sw->uid);
+
+		ret = tb_switch_set_uuid(sw);
+		if (ret) {
+			dev_err(&sw->dev, "failed to set UUID\n");
+			return ret;
+		}
+
+		for (i = 0; i <= sw->config.max_port_number; i++) {
+			if (sw->ports[i].disabled) {
+				tb_port_dbg(&sw->ports[i], "disabled by eeprom\n");
+				continue;
+			}
+			ret = tb_init_port(&sw->ports[i]);
+			if (ret) {
+				dev_err(&sw->dev, "failed to initialize port %d\n", i);
+				return ret;
+			}
+		}
+
+		tb_check_quirks(sw);
+
+		tb_switch_default_link_ports(sw);
+
+		ret = tb_switch_update_link_attributes(sw);
+		if (ret)
+			return ret;
+
+		ret = tb_switch_clx_init(sw);
+		if (ret)
+			return ret;
+
+		ret = tb_switch_tmu_init(sw);
+		if (ret)
+			return ret;
+	}
+
+	ret = tb_switch_port_hotplug_enable(sw);
+	if (ret)
+		return ret;
+
+	ret = device_add(&sw->dev);
+	if (ret) {
+		dev_err(&sw->dev, "failed to add device: %d\n", ret);
+		return ret;
+	}
+
+	if (tb_route(sw)) {
+		dev_info(&sw->dev, "new device found, vendor=%#x device=%#x\n",
+			 sw->vendor, sw->device);
+		if (sw->vendor_name && sw->device_name)
+			dev_info(&sw->dev, "%s %s\n", sw->vendor_name,
+				 sw->device_name);
+	}
+
+	ret = usb4_switch_add_ports(sw);
+	if (ret) {
+		dev_err(&sw->dev, "failed to add USB4 ports\n");
+		goto err_del;
+	}
+
+	ret = tb_switch_nvm_add(sw);
+	if (ret) {
+		dev_err(&sw->dev, "failed to add NVM devices\n");
+		goto err_ports;
+	}
+
+	/*
+	 * Thunderbolt routers do not generate wakeups themselves but
+	 * they forward wakeups from tunneled protocols, so enable it
+	 * here.
+	 */
+	device_init_wakeup(&sw->dev, true);
+
+	pm_runtime_set_active(&sw->dev);
+	if (sw->rpm) {
+		pm_runtime_set_autosuspend_delay(&sw->dev, TB_AUTOSUSPEND_DELAY);
+		pm_runtime_use_autosuspend(&sw->dev);
+		pm_runtime_mark_last_busy(&sw->dev);
+		pm_runtime_enable(&sw->dev);
+		pm_request_autosuspend(&sw->dev);
+	}
+
+	tb_switch_debugfs_init(sw);
+	return 0;
+
+err_ports:
+	usb4_switch_remove_ports(sw);
+err_del:
+	device_del(&sw->dev);
+
+	return ret;
+}
+
+/**
+ * tb_switch_remove() - Remove and release a switch
+ * @sw: Switch to remove
+ *
+ * This will remove the switch from the domain and release it after last
+ * reference count drops to zero. If there are switches connected below
+ * this switch, they will be removed as well.
+ */
+void tb_switch_remove(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	tb_switch_debugfs_remove(sw);
+
+	if (sw->rpm) {
+		pm_runtime_get_sync(&sw->dev);
+		pm_runtime_disable(&sw->dev);
+	}
+
+	/* port 0 is the switch itself and never has a remote */
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port)) {
+			tb_switch_remove(port->remote->sw);
+			port->remote = NULL;
+		} else if (port->xdomain) {
+			tb_xdomain_remove(port->xdomain);
+			port->xdomain = NULL;
+		}
+
+		/* Remove any downstream retimers */
+		tb_retimer_remove_all(port);
+	}
+
+	if (!sw->is_unplugged)
+		tb_plug_events_active(sw, false);
+
+	tb_switch_nvm_remove(sw);
+	usb4_switch_remove_ports(sw);
+
+	if (tb_route(sw))
+		dev_info(&sw->dev, "device disconnected\n");
+	device_unregister(&sw->dev);
+}
+
+/**
+ * tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
+ * @sw: Router to mark unplugged
+ */
+void tb_sw_set_unplugged(struct tb_switch *sw)
+{
+	struct tb_port *port;
+
+	if (sw == sw->tb->root_switch) {
+		tb_sw_WARN(sw, "cannot unplug root switch\n");
+		return;
+	}
+	if (sw->is_unplugged) {
+		tb_sw_WARN(sw, "is_unplugged already set\n");
+		return;
+	}
+	sw->is_unplugged = true;
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port))
+			tb_sw_set_unplugged(port->remote->sw);
+		else if (port->xdomain)
+			port->xdomain->is_unplugged = true;
+	}
+}
+
+static int tb_switch_set_wake(struct tb_switch *sw, unsigned int flags)
+{
+	if (flags)
+		tb_sw_dbg(sw, "enabling wakeup: %#x\n", flags);
+	else
+		tb_sw_dbg(sw, "disabling wakeup\n");
+
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_set_wake(sw, flags);
+	return tb_lc_set_wake(sw, flags);
+}
+
+int tb_switch_resume(struct tb_switch *sw)
+{
+	struct tb_port *port;
+	int err;
+
+	tb_sw_dbg(sw, "resuming switch\n");
+
+	/*
+	 * Check for UID of the connected switches except for root
+	 * switch which we assume cannot be removed.
+	 */
+	if (tb_route(sw)) {
+		u64 uid;
+
+		/*
+		 * Check first that we can still read the switch config
+		 * space. It may be that there is now another domain
+		 * connected.
+		 */
+		err = tb_cfg_get_upstream_port(sw->tb->ctl, tb_route(sw));
+		if (err < 0) {
+			tb_sw_info(sw, "switch not present anymore\n");
+			return err;
+		}
+
+		/* We don't have any way to confirm this was the same device */
+		if (!sw->uid)
+			return -ENODEV;
+
+		if (tb_switch_is_usb4(sw))
+			err = usb4_switch_read_uid(sw, &uid);
+		else
+			err = tb_drom_read_uid_only(sw, &uid);
+		if (err) {
+			tb_sw_warn(sw, "uid read failed\n");
+			return err;
+		}
+		if (sw->uid != uid) {
+			tb_sw_info(sw,
+				"changed while suspended (uid %#llx -> %#llx)\n",
+				sw->uid, uid);
+			return -ENODEV;
+		}
+	}
+
+	err = tb_switch_configure(sw);
+	if (err)
+		return err;
+
+	/* Disable wakes */
+	tb_switch_set_wake(sw, 0);
+
+	err = tb_switch_tmu_init(sw);
+	if (err)
+		return err;
+
+	/* check for surviving downstream switches */
+	tb_switch_for_each_port(sw, port) {
+		if (!tb_port_is_null(port))
+			continue;
+
+		if (!tb_port_resume(port))
+			continue;
+
+		if (tb_wait_for_port(port, true) <= 0) {
+			tb_port_warn(port,
+				     "lost during suspend, disconnecting\n");
+			if (tb_port_has_remote(port))
+				tb_sw_set_unplugged(port->remote->sw);
+			else if (port->xdomain)
+				port->xdomain->is_unplugged = true;
+		} else {
+			/*
+			 * Always unlock the port so the downstream
+			 * switch/domain is accessible.
+			 */
+			if (tb_port_unlock(port))
+				tb_port_warn(port, "failed to unlock port\n");
+			if (port->remote && tb_switch_resume(port->remote->sw)) {
+				tb_port_warn(port,
+					     "lost during suspend, disconnecting\n");
+				tb_sw_set_unplugged(port->remote->sw);
+			}
+		}
+	}
+	return 0;
+}
+
+/**
+ * tb_switch_suspend() - Put a switch to sleep
+ * @sw: Switch to suspend
+ * @runtime: Is this runtime suspend or system sleep
+ *
+ * Suspends router and all its children. Enables wakes according to
+ * value of @runtime and then sets sleep bit for the router. If @sw is
+ * host router the domain is ready to go to sleep once this function
+ * returns.
+ */
+void tb_switch_suspend(struct tb_switch *sw, bool runtime)
+{
+	unsigned int flags = 0;
+	struct tb_port *port;
+	int err;
+
+	tb_sw_dbg(sw, "suspending switch\n");
+
+	/*
+	 * Actually only needed for Titan Ridge but for simplicity can be
+	 * done for USB4 device too as CLx is re-enabled at resume.
+	 */
+	tb_switch_clx_disable(sw);
+
+	err = tb_plug_events_active(sw, false);
+	if (err)
+		return;
+
+	tb_switch_for_each_port(sw, port) {
+		if (tb_port_has_remote(port))
+			tb_switch_suspend(port->remote->sw, runtime);
+	}
+
+	if (runtime) {
+		/* Trigger wake when something is plugged in/out */
+		flags |= TB_WAKE_ON_CONNECT | TB_WAKE_ON_DISCONNECT;
+		flags |= TB_WAKE_ON_USB4;
+		flags |= TB_WAKE_ON_USB3 | TB_WAKE_ON_PCIE | TB_WAKE_ON_DP;
+	} else if (device_may_wakeup(&sw->dev)) {
+		flags |= TB_WAKE_ON_USB4 | TB_WAKE_ON_USB3 | TB_WAKE_ON_PCIE;
+	}
+
+	tb_switch_set_wake(sw, flags);
+
+	if (tb_switch_is_usb4(sw))
+		usb4_switch_set_sleep(sw);
+	else
+		tb_lc_set_sleep(sw);
+}
+
+/**
+ * tb_switch_query_dp_resource() - Query availability of DP resource
+ * @sw: Switch whose DP resource is queried
+ * @in: DP IN port
+ *
+ * Queries availability of DP resource for DP tunneling using switch
+ * specific means. Returns %true if resource is available.
+ */
+bool tb_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	if (tb_switch_is_usb4(sw))
+		return usb4_switch_query_dp_resource(sw, in);
+	return tb_lc_dp_sink_query(sw, in);
+}
+
+/**
+ * tb_switch_alloc_dp_resource() - Allocate available DP resource
+ * @sw: Switch whose DP resource is allocated
+ * @in: DP IN port
+ *
+ * Allocates DP resource for DP tunneling. The resource must be
+ * available for this to succeed (see tb_switch_query_dp_resource()).
+ * Returns %0 in success and negative errno otherwise.
+ */
+int tb_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	int ret;
+
+	if (tb_switch_is_usb4(sw))
+		ret = usb4_switch_alloc_dp_resource(sw, in);
+	else
+		ret = tb_lc_dp_sink_alloc(sw, in);
+
+	if (ret)
+		tb_sw_warn(sw, "failed to allocate DP resource for port %d\n",
+			   in->port);
+	else
+		tb_sw_dbg(sw, "allocated DP resource for port %d\n", in->port);
+
+	return ret;
+}
+
+/**
+ * tb_switch_dealloc_dp_resource() - De-allocate DP resource
+ * @sw: Switch whose DP resource is de-allocated
+ * @in: DP IN port
+ *
+ * De-allocates DP resource that was previously allocated for DP
+ * tunneling.
+ */
+void tb_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
+{
+	int ret;
+
+	if (tb_switch_is_usb4(sw))
+		ret = usb4_switch_dealloc_dp_resource(sw, in);
+	else
+		ret = tb_lc_dp_sink_dealloc(sw, in);
+
+	if (ret)
+		tb_sw_warn(sw, "failed to de-allocate DP resource for port %d\n",
+			   in->port);
+	else
+		tb_sw_dbg(sw, "released DP resource for port %d\n", in->port);
+}
+
+struct tb_sw_lookup {
+	struct tb *tb;
+	u8 link;
+	u8 depth;
+	const uuid_t *uuid;
+	u64 route;
+};
+
+static int tb_switch_match(struct device *dev, const void *data)
+{
+	struct tb_switch *sw = tb_to_switch(dev);
+	const struct tb_sw_lookup *lookup = data;
+
+	if (!sw)
+		return 0;
+	if (sw->tb != lookup->tb)
+		return 0;
+
+	if (lookup->uuid)
+		return !memcmp(sw->uuid, lookup->uuid, sizeof(*lookup->uuid));
+
+	if (lookup->route) {
+		return sw->config.route_lo == lower_32_bits(lookup->route) &&
+		       sw->config.route_hi == upper_32_bits(lookup->route);
+	}
+
+	/* Root switch is matched only by depth */
+	if (!lookup->depth)
+		return !sw->depth;
+
+	return sw->link == lookup->link && sw->depth == lookup->depth;
+}
+
+/**
+ * tb_switch_find_by_link_depth() - Find switch by link and depth
+ * @tb: Domain the switch belongs
+ * @link: Link number the switch is connected
+ * @depth: Depth of the switch in link
+ *
+ * Returned switch has reference count increased so the caller needs to
+ * call tb_switch_put() when done with the switch.
+ */
+struct tb_switch *tb_switch_find_by_link_depth(struct tb *tb, u8 link, u8 depth)
+{
+	struct tb_sw_lookup lookup;
+	struct device *dev;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.tb = tb;
+	lookup.link = link;
+	lookup.depth = depth;
+
+	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
+	if (dev)
+		return tb_to_switch(dev);
+
+	return NULL;
+}
+
+/**
+ * tb_switch_find_by_uuid() - Find switch by UUID
+ * @tb: Domain the switch belongs
+ * @uuid: UUID to look for
+ *
+ * Returned switch has reference count increased so the caller needs to
+ * call tb_switch_put() when done with the switch.
+ */
+struct tb_switch *tb_switch_find_by_uuid(struct tb *tb, const uuid_t *uuid)
+{
+	struct tb_sw_lookup lookup;
+	struct device *dev;
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.tb = tb;
+	lookup.uuid = uuid;
+
+	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
+	if (dev)
+		return tb_to_switch(dev);
+
+	return NULL;
+}
+
+/**
+ * tb_switch_find_by_route() - Find switch by route string
+ * @tb: Domain the switch belongs
+ * @route: Route string to look for
+ *
+ * Returned switch has reference count increased so the caller needs to
+ * call tb_switch_put() when done with the switch.
+ */
+struct tb_switch *tb_switch_find_by_route(struct tb *tb, u64 route)
+{
+	struct tb_sw_lookup lookup;
+	struct device *dev;
+
+	if (!route)
+		return tb_switch_get(tb->root_switch);
+
+	memset(&lookup, 0, sizeof(lookup));
+	lookup.tb = tb;
+	lookup.route = route;
+
+	dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
+	if (dev)
+		return tb_to_switch(dev);
+
+	return NULL;
+}
+
+/**
+ * tb_switch_find_port() - return the first port of @type on @sw or NULL
+ * @sw: Switch to find the port from
+ * @type: Port type to look for
+ */
+struct tb_port *tb_switch_find_port(struct tb_switch *sw,
+				    enum tb_port_type type)
+{
+	struct tb_port *port;
+
+	tb_switch_for_each_port(sw, port) {
+		if (port->config.type == type)
+			return port;
+	}
+
+	return NULL;
+}
+
+/*
+ * Can be used for read/write a specified PCIe bridge for any Thunderbolt 3
+ * device. For now used only for Titan Ridge.
+ */
+static int tb_switch_pcie_bridge_write(struct tb_switch *sw, unsigned int bridge,
+				       unsigned int pcie_offset, u32 value)
+{
+	u32 offset, command, val;
+	int ret;
+
+	if (sw->generation != 3)
+		return -EOPNOTSUPP;
+
+	offset = sw->cap_plug_events + TB_PLUG_EVENTS_PCIE_WR_DATA;
+	ret = tb_sw_write(sw, &value, TB_CFG_SWITCH, offset, 1);
+	if (ret)
+		return ret;
+
+	command = pcie_offset & TB_PLUG_EVENTS_PCIE_CMD_DW_OFFSET_MASK;
+	command |= BIT(bridge + TB_PLUG_EVENTS_PCIE_CMD_BR_SHIFT);
+	command |= TB_PLUG_EVENTS_PCIE_CMD_RD_WR_MASK;
+	command |= TB_PLUG_EVENTS_PCIE_CMD_COMMAND_VAL
+			<< TB_PLUG_EVENTS_PCIE_CMD_COMMAND_SHIFT;
+	command |= TB_PLUG_EVENTS_PCIE_CMD_REQ_ACK_MASK;
+
+	offset = sw->cap_plug_events + TB_PLUG_EVENTS_PCIE_CMD;
+
+	ret = tb_sw_write(sw, &command, TB_CFG_SWITCH, offset, 1);
+	if (ret)
+		return ret;
+
+	ret = tb_switch_wait_for_bit(sw, offset,
+				     TB_PLUG_EVENTS_PCIE_CMD_REQ_ACK_MASK, 0, 100);
+	if (ret)
+		return ret;
+
+	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
+	if (ret)
+		return ret;
+
+	if (val & TB_PLUG_EVENTS_PCIE_CMD_TIMEOUT_MASK)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+/**
+ * tb_switch_pcie_l1_enable() - Enable PCIe link to enter L1 state
+ * @sw: Router to enable PCIe L1
+ *
+ * For Titan Ridge switch to enter CLx state, its PCIe bridges shall enable
+ * entry to PCIe L1 state. Shall be called after the upstream PCIe tunnel
+ * was configured. Due to Intel platforms limitation, shall be called only
+ * for first hop switch.
+ */
+int tb_switch_pcie_l1_enable(struct tb_switch *sw)
+{
+	struct tb_switch *parent = tb_switch_parent(sw);
+	int ret;
+
+	if (!tb_route(sw))
+		return 0;
+
+	if (!tb_switch_is_titan_ridge(sw))
+		return 0;
+
+	/* Enable PCIe L1 enable only for first hop router (depth = 1) */
+	if (tb_route(parent))
+		return 0;
+
+	/* Write to downstream PCIe bridge #5 aka Dn4 */
+	ret = tb_switch_pcie_bridge_write(sw, 5, 0x143, 0x0c7806b1);
+	if (ret)
+		return ret;
+
+	/* Write to Upstream PCIe bridge #0 aka Up0 */
+	return tb_switch_pcie_bridge_write(sw, 0, 0x143, 0x0c5806b1);
+}
+
+/**
+ * tb_switch_xhci_connect() - Connect internal xHCI
+ * @sw: Router whose xHCI to connect
+ *
+ * Can be called to any router. For Alpine Ridge and Titan Ridge
+ * performs special flows that bring the xHCI functional for any device
+ * connected to the type-C port. Call only after PCIe tunnel has been
+ * established. The function only does the connect if not done already
+ * so can be called several times for the same router.
+ */
+int tb_switch_xhci_connect(struct tb_switch *sw)
+{
+	struct tb_port *port1, *port3;
+	int ret;
+
+	if (sw->generation != 3)
+		return 0;
+
+	port1 = &sw->ports[1];
+	port3 = &sw->ports[3];
+
+	if (tb_switch_is_alpine_ridge(sw)) {
+		bool usb_port1, usb_port3, xhci_port1, xhci_port3;
+
+		usb_port1 = tb_lc_is_usb_plugged(port1);
+		usb_port3 = tb_lc_is_usb_plugged(port3);
+		xhci_port1 = tb_lc_is_xhci_connected(port1);
+		xhci_port3 = tb_lc_is_xhci_connected(port3);
+
+		/* Figure out correct USB port to connect */
+		if (usb_port1 && !xhci_port1) {
+			ret = tb_lc_xhci_connect(port1);
+			if (ret)
+				return ret;
+		}
+		if (usb_port3 && !xhci_port3)
+			return tb_lc_xhci_connect(port3);
+	} else if (tb_switch_is_titan_ridge(sw)) {
+		ret = tb_lc_xhci_connect(port1);
+		if (ret)
+			return ret;
+		return tb_lc_xhci_connect(port3);
+	}
+
+	return 0;
+}
+
+/**
+ * tb_switch_xhci_disconnect() - Disconnect internal xHCI
+ * @sw: Router whose xHCI to disconnect
+ *
+ * The opposite of tb_switch_xhci_connect(). Disconnects xHCI on both
+ * ports.
+ */
+void tb_switch_xhci_disconnect(struct tb_switch *sw)
+{
+	if (sw->generation == 3) {
+		struct tb_port *port1 = &sw->ports[1];
+		struct tb_port *port3 = &sw->ports[3];
+
+		tb_lc_xhci_disconnect(port1);
+		tb_port_dbg(port1, "disconnected xHCI\n");
+		tb_lc_xhci_disconnect(port3);
+		tb_port_dbg(port3, "disconnected xHCI\n");
+	}
+}