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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // 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/nvmem-provider.h>
 #include <linux/pm_runtime.h>
 #include <linux/sched/signal.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 
 #include "tb.h"
 
 /* Switch NVM support */
 
 #define NVM_CSS         0x10
 
 struct nvm_auth_status {
     struct list_head list;
     uuid_t uuid;
     u32 status;
 };
 
 static bool clx_enabled = true;
 module_param_named(clx, clx_enabled, bool, 0444);
 MODULE_PARM_DESC(clx, "allow low power states on the high-speed lanes (default: true)");
 
 /*
  * 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, hdr_size;
     const u8 *buf = sw->nvm->buf;
     u16 ds_size;
     int ret;
 
     if (!buf)
         return -EINVAL;
 
     image_size = sw->nvm->buf_data_size;
     if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
         return -EINVAL;
 
     /*
      * FARB pointer must point inside the image and must at least
      * contain parts of the digital section we will be reading here.
      */
     hdr_size = (*(u32 *)buf) & 0xffffff;
     if (hdr_size + NVM_DEVID + 2 >= image_size)
         return -EINVAL;
 
     /* Digital section start should be aligned to 4k page */
     if (!IS_ALIGNED(hdr_size, SZ_4K))
         return -EINVAL;
 
     /*
      * Read digital section size and check that it also fits inside
      * the image.
      */
     ds_size = *(u16 *)(buf + hdr_size);
     if (ds_size >= image_size)
         return -EINVAL;
 
     if (!sw->safe_mode) {
         u16 device_id;
 
         /*
          * Make sure the device ID in the image matches the one
          * we read from the switch config space.
          */
         device_id = *(u16 *)(buf + hdr_size + NVM_DEVID);
         if (device_id != sw->config.device_id)
             return -EINVAL;
 
         if (sw->generation < 3) {
             /* Write CSS headers first */
             ret = dma_port_flash_write(sw->dma_port,
                 DMA_PORT_CSS_ADDRESS, buf + NVM_CSS,
                 DMA_PORT_CSS_MAX_SIZE);
             if (ret)
                 return ret;
         }
 
         /* Skip headers in the image */
         buf += hdr_size;
         image_size -= hdr_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)
         sw->nvm->flushed = true;
     return ret;
 }
 
 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 inline int 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_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);
     } else 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;
 }
 
 static int tb_switch_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 = 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 tb_switch_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;
     u32 val;
     int ret;
 
     if (!nvm_readable(sw))
         return 0;
 
     /*
      * The NVM format of non-Intel hardware is not known so
      * currently restrict NVM upgrade for Intel hardware. We may
      * relax this in the future when we learn other NVM formats.
      */
     if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL &&
         sw->config.vendor_id != 0x8087) {
         dev_info(&sw->dev,
              "NVM format of vendor %#x is not known, disabling NVM upgrade\n",
              sw->config.vendor_id);
         return 0;
     }
 
     nvm = tb_nvm_alloc(&sw->dev);
     if (IS_ERR(nvm))
         return PTR_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) {
         u32 nvm_size, hdr_size;
 
         ret = nvm_read(sw, NVM_FLASH_SIZE, &val, sizeof(val));
         if (ret)
             goto err_nvm;
 
         hdr_size = sw->generation < 3 ? SZ_8K : SZ_16K;
         nvm_size = (SZ_1M << (val & 7)) / 8;
         nvm_size = (nvm_size - hdr_size) / 2;
 
         ret = nvm_read(sw, NVM_VERSION, &val, sizeof(val));
         if (ret)
             goto err_nvm;
 
         nvm->major = val >> 16;
         nvm->minor = val >> 8;
 
         ret = tb_nvm_add_active(nvm, nvm_size, tb_switch_nvm_read);
         if (ret)
             goto err_nvm;
     }
 
     if (!sw->no_nvm_upgrade) {
         ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE,
                         tb_switch_nvm_write);
         if (ret)
             goto err_nvm;
     }
 
     sw->nvm = nvm;
     return 0;
 
 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);
         if (state < 0)
             return state;
         if (state == TB_PORT_DISABLED) {
             tb_port_dbg(port, "is disabled (state: 0)\n");
             return 0;
         }
         if (state == TB_PORT_UNPLUGGED) {
             if (wait_if_unplugged) {
                 /* used during resume */
                 tb_port_dbg(port,
                         "is unplugged (state: 7), retrying...\n");
                 msleep(100);
                 continue;
             }
             tb_port_dbg(port, "is unplugged (state: 7)\n");
             return 0;
         }
         if (state == TB_PORT_UP) {
             tb_port_dbg(port, "is connected, link is up (state: 2)\n");
             return 1;
         }
 
         /*
          * 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 %sabled\n", enable ? "en" : "dis");
     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 (tb_switch_is_usb4(port->sw)) {
             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;
     return speed == LANE_ADP_CS_1_CURRENT_SPEED_GEN3 ? 20 : 10;
 }
 
 /**
  * tb_port_get_link_width() - Get current link width
  * @port: Port to check (USB4 or CIO)
  *
  * Returns link width. Return values can be 1 (Single-Lane), 2 (Dual-Lane)
  * 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;
 
     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, int width)
 {
     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);
 }
 
 /**
  * tb_port_set_link_width() - Set target link width of the lane adapter
  * @port: Lane adapter
  * @width: Target link width (%1 or %2)
  *
  * 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, unsigned int 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 1:
         val |= LANE_ADP_CS_1_TARGET_WIDTH_SINGLE <<
             LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
         break;
     case 2:
         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.
  *
  * As a side effect sets @port->bonding accordingly (and does the same
  * for lane 1 too).
  *
  * Return: %0 in case of success and negative errno in case of error
  */
 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;
 
     ret = tb_port_write(port, &val, TB_CFG_PORT,
                 port->cap_phy + LANE_ADP_CS_1, 1);
     if (ret)
         return ret;
 
     /*
      * When lane 0 bonding is set it will affect lane 1 too so
      * update both.
      */
     port->bonded = bonding;
     port->dual_link_port->bonded = bonding;
 
     return 0;
 }
 
 /**
  * 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)
 {
     int ret;
 
     /*
      * Enable lane bonding for both links if not already enabled by
      * for example the boot firmware.
      */
     ret = tb_port_get_link_width(port);
     if (ret == 1) {
         ret = tb_port_set_link_width(port, 2);
         if (ret)
             goto err_lane0;
     }
 
     ret = tb_port_get_link_width(port->dual_link_port);
     if (ret == 1) {
         ret = tb_port_set_link_width(port->dual_link_port, 2);
         if (ret)
             goto err_lane0;
     }
 
     ret = tb_port_set_lane_bonding(port, true);
     if (ret)
         goto err_lane1;
 
     return 0;
 
 err_lane1:
     tb_port_set_link_width(port->dual_link_port, 1);
 err_lane0:
     tb_port_set_link_width(port, 1);
     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, 1);
     tb_port_set_link_width(port, 1);
 }
 
 /**
  * tb_port_wait_for_link_width() - Wait until link reaches specific width
  * @port: Port to wait for
  * @width: Expected link width (%1 or %2)
  * @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.
  */
 int tb_port_wait_for_link_width(struct tb_port *port, int width,
                 int timeout_msec)
 {
     ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
     int ret;
 
     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) {
             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 sprintf(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 sprintf(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 sprintf(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 sprintf(buf, "%s\n", sw->device_name ? 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 sprintf(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 = sprintf(buf, "%*phN\n", TB_SWITCH_KEY_SIZE, sw->key);
     else
         ret = sprintf(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 sprintf(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 lanes_show(struct device *dev, struct device_attribute *attr,
               char *buf)
 {
     struct tb_switch *sw = tb_to_switch(dev);
 
     return sprintf(buf, "%u\n", sw->link_width);
 }
 
 /*
  * Currently link has same amount of lanes both directions (1 or 2) but
  * expose them separately to allow possible asymmetric links in the future.
  */
 static DEVICE_ATTR(rx_lanes, 0444, lanes_show, NULL);
 static DEVICE_ATTR(tx_lanes, 0444, 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 sprintf(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 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 = sprintf(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 sprintf(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 sprintf(buf, "%s\n", sw->vendor_name ? 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 sprintf(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(struct device *dev, struct kobj_uevent_env *env)
 {
     struct tb_switch *sw = tb_to_switch(dev);
     const char *type;
 
     if (sw->config.thunderbolt_version == USB4_VERSION_1_0) {
         if (add_uevent_var(env, "USB4_VERSION=1.0"))
             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)
 {
     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;
 
     default:
         if (tb_switch_is_usb4(sw))
             return 4;
 
         /*
          * 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.
          */
         sw->config.cmuv = USB4_VERSION_1_0;
         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);
 }
 
 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_switch *parent = tb_to_switch(sw->dev.parent);
     struct tb_port *up, *down;
     u64 route = tb_route(sw);
     int ret;
 
     if (!route)
         return 0;
 
     if (!tb_switch_lane_bonding_possible(sw))
         return 0;
 
     up = tb_upstream_port(sw);
     down = tb_port_at(route, parent);
 
     if (!tb_port_is_width_supported(up, 2) ||
         !tb_port_is_width_supported(down, 2))
         return 0;
 
     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;
     }
 
     ret = tb_port_wait_for_link_width(down, 2, 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_switch *parent = tb_to_switch(sw->dev.parent);
     struct tb_port *up, *down;
 
     if (!tb_route(sw))
         return;
 
     up = tb_upstream_port(sw);
     if (!up->bonded)
         return;
 
     down = tb_port_at(tb_route(sw), parent);
 
     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.
      */
     if (tb_port_wait_for_link_width(down, 1, 100) == -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");
 }
 
 /**
  * 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);
 
         tb_check_quirks(sw);
 
         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_switch_default_link_ports(sw);
 
         ret = tb_switch_update_link_attributes(sw);
         if (ret)
             return ret;
 
         ret = tb_switch_tmu_init(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.
      * CL0s and CL1 are enabled and supported together.
      */
     if (tb_switch_is_clx_enabled(sw, TB_CL1)) {
         if (tb_switch_disable_clx(sw, TB_CL1))
             tb_sw_warn(sw, "failed to disable %s on upstream port\n",
                    tb_switch_clx_name(TB_CL1));
     }
 
     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;
 }
 
 static int __tb_port_pm_secondary_set(struct tb_port *port, bool secondary)
 {
     u32 phy;
     int ret;
 
     ret = tb_port_read(port, &phy, TB_CFG_PORT,
                port->cap_phy + LANE_ADP_CS_1, 1);
     if (ret)
         return ret;
 
     if (secondary)
         phy |= LANE_ADP_CS_1_PMS;
     else
         phy &= ~LANE_ADP_CS_1_PMS;
 
     return tb_port_write(port, &phy, TB_CFG_PORT,
                  port->cap_phy + LANE_ADP_CS_1, 1);
 }
 
 static int tb_port_pm_secondary_enable(struct tb_port *port)
 {
     return __tb_port_pm_secondary_set(port, true);
 }
 
 static int tb_port_pm_secondary_disable(struct tb_port *port)
 {
     return __tb_port_pm_secondary_set(port, false);
 }
 
 static int tb_switch_pm_secondary_resolve(struct tb_switch *sw)
 {
     struct tb_switch *parent = tb_switch_parent(sw);
     struct tb_port *up, *down;
     int ret;
 
     if (!tb_route(sw))
         return 0;
 
     up = tb_upstream_port(sw);
     down = tb_port_at(tb_route(sw), parent);
     ret = tb_port_pm_secondary_enable(up);
     if (ret)
         return ret;
 
     return tb_port_pm_secondary_disable(down);
 }
 
 /* Called for USB4 or Titan Ridge routers only */
 static bool tb_port_clx_supported(struct tb_port *port, enum tb_clx clx)
 {
     u32 mask, val;
     bool ret;
 
     /* Don't enable CLx in case of two single-lane links */
     if (!port->bonded && port->dual_link_port)
         return false;
 
     /* Don't enable CLx in case of inter-domain link */
     if (port->xdomain)
         return false;
 
     if (tb_switch_is_usb4(port->sw)) {
         if (!usb4_port_clx_supported(port))
             return false;
     } else if (!tb_lc_is_clx_supported(port)) {
         return false;
     }
 
     switch (clx) {
     case TB_CL1:
         /* CL0s and CL1 are enabled and supported together */
         mask = LANE_ADP_CS_0_CL0S_SUPPORT | LANE_ADP_CS_0_CL1_SUPPORT;
         break;
 
     /* For now we support only CL0s and CL1. Not CL2 */
     case TB_CL2:
     default:
         return false;
     }
 
     ret = tb_port_read(port, &val, TB_CFG_PORT,
                port->cap_phy + LANE_ADP_CS_0, 1);
     if (ret)
         return false;
 
     return !!(val & mask);
 }
 
 static int __tb_port_clx_set(struct tb_port *port, enum tb_clx clx, bool enable)
 {
     u32 phy, mask;
     int ret;
 
     /* CL0s and CL1 are enabled and supported together */
     if (clx == TB_CL1)
         mask = LANE_ADP_CS_1_CL0S_ENABLE | LANE_ADP_CS_1_CL1_ENABLE;
     else
         /* For now we support only CL0s and CL1. Not CL2 */
         return -EOPNOTSUPP;
 
     ret = tb_port_read(port, &phy, TB_CFG_PORT,
                port->cap_phy + LANE_ADP_CS_1, 1);
     if (ret)
         return ret;
 
     if (enable)
         phy |= mask;
     else
         phy &= ~mask;
 
     return tb_port_write(port, &phy, TB_CFG_PORT,
                  port->cap_phy + LANE_ADP_CS_1, 1);
 }
 
 static int tb_port_clx_disable(struct tb_port *port, enum tb_clx clx)
 {
     return __tb_port_clx_set(port, clx, false);
 }
 
 static int tb_port_clx_enable(struct tb_port *port, enum tb_clx clx)
 {
     return __tb_port_clx_set(port, clx, true);
 }
 
 static int __tb_switch_enable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
     struct tb_switch *parent = tb_switch_parent(sw);
     bool up_clx_support, down_clx_support;
     struct tb_port *up, *down;
     int ret;
 
     if (!tb_switch_is_clx_supported(sw))
         return 0;
 
     /*
      * Enable CLx for host router's downstream port as part of the
      * downstream router enabling procedure.
      */
     if (!tb_route(sw))
         return 0;
 
     /* Enable CLx only for first hop router (depth = 1) */
     if (tb_route(parent))
         return 0;
 
     ret = tb_switch_pm_secondary_resolve(sw);
     if (ret)
         return ret;
 
     up = tb_upstream_port(sw);
     down = tb_port_at(tb_route(sw), parent);
 
     up_clx_support = tb_port_clx_supported(up, clx);
     down_clx_support = tb_port_clx_supported(down, clx);
 
     tb_port_dbg(up, "%s %ssupported\n", tb_switch_clx_name(clx),
             up_clx_support ? "" : "not ");
     tb_port_dbg(down, "%s %ssupported\n", tb_switch_clx_name(clx),
             down_clx_support ? "" : "not ");
 
     if (!up_clx_support || !down_clx_support)
         return -EOPNOTSUPP;
 
     ret = tb_port_clx_enable(up, clx);
     if (ret)
         return ret;
 
     ret = tb_port_clx_enable(down, clx);
     if (ret) {
         tb_port_clx_disable(up, clx);
         return ret;
     }
 
     ret = tb_switch_mask_clx_objections(sw);
     if (ret) {
         tb_port_clx_disable(up, clx);
         tb_port_clx_disable(down, clx);
         return ret;
     }
 
     sw->clx = clx;
 
     tb_port_dbg(up, "%s enabled\n", tb_switch_clx_name(clx));
     return 0;
 }
 
 /**
  * tb_switch_enable_clx() - Enable CLx on upstream port of specified router
  * @sw: Router to enable CLx for
  * @clx: The CLx state to enable
  *
  * Enable CLx state only for first hop router. That is the most common
  * use-case, that is intended for better thermal management, and so helps
  * to improve performance. CLx is enabled only if both sides of the link
  * support CLx, and if both sides of the link are not configured as two
  * single lane links and only if the link is not inter-domain link. The
  * complete set of conditions is described in CM Guide 1.0 section 8.1.
  *
  * Return: Returns 0 on success or an error code on failure.
  */
 int tb_switch_enable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
     struct tb_switch *root_sw = sw->tb->root_switch;
 
     if (!clx_enabled)
         return 0;
 
     /*
      * CLx is not enabled and validated on Intel USB4 platforms before
      * Alder Lake.
      */
     if (root_sw->generation < 4 || tb_switch_is_tiger_lake(root_sw))
         return 0;
 
     switch (clx) {
     case TB_CL1:
         /* CL0s and CL1 are enabled and supported together */
         return __tb_switch_enable_clx(sw, clx);
 
     default:
         return -EOPNOTSUPP;
     }
 }
 
 static int __tb_switch_disable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
     struct tb_switch *parent = tb_switch_parent(sw);
     struct tb_port *up, *down;
     int ret;
 
     if (!tb_switch_is_clx_supported(sw))
         return 0;
 
     /*
      * Disable CLx for host router's downstream port as part of the
      * downstream router enabling procedure.
      */
     if (!tb_route(sw))
         return 0;
 
     /* Disable CLx only for first hop router (depth = 1) */
     if (tb_route(parent))
         return 0;
 
     up = tb_upstream_port(sw);
     down = tb_port_at(tb_route(sw), parent);
     ret = tb_port_clx_disable(up, clx);
     if (ret)
         return ret;
 
     ret = tb_port_clx_disable(down, clx);
     if (ret)
         return ret;
 
     sw->clx = TB_CLX_DISABLE;
 
     tb_port_dbg(up, "%s disabled\n", tb_switch_clx_name(clx));
     return 0;
 }
 
 /**
  * tb_switch_disable_clx() - Disable CLx on upstream port of specified router
  * @sw: Router to disable CLx for
  * @clx: The CLx state to disable
  *
  * Return: Returns 0 on success or an error code on failure.
  */
 int tb_switch_disable_clx(struct tb_switch *sw, enum tb_clx clx)
 {
     if (!clx_enabled)
         return 0;
 
     switch (clx) {
     case TB_CL1:
         /* CL0s and CL1 are enabled and supported together */
         return __tb_switch_disable_clx(sw, clx);
 
     default:
         return -EOPNOTSUPP;
     }
 }
 
 /**
  * tb_switch_mask_clx_objections() - Mask CLx objections for a router
  * @sw: Router to mask objections for
  *
  * Mask the objections coming from the second depth routers in order to
  * stop these objections from interfering with the CLx states of the first
  * depth link.
  */
 int tb_switch_mask_clx_objections(struct tb_switch *sw)
 {
     int up_port = sw->config.upstream_port_number;
     u32 offset, val[2], mask_obj, unmask_obj;
     int ret, i;
 
     /* Only Titan Ridge of pre-USB4 devices support CLx states */
     if (!tb_switch_is_titan_ridge(sw))
         return 0;
 
     if (!tb_route(sw))
         return 0;
 
     /*
      * In Titan Ridge there are only 2 dual-lane Thunderbolt ports:
      * Port A consists of lane adapters 1,2 and
      * Port B consists of lane adapters 3,4
      * If upstream port is A, (lanes are 1,2), we mask objections from
      * port B (lanes 3,4) and unmask objections from Port A and vice-versa.
      */
     if (up_port == 1) {
         mask_obj = TB_LOW_PWR_C0_PORT_B_MASK;
         unmask_obj = TB_LOW_PWR_C1_PORT_A_MASK;
         offset = TB_LOW_PWR_C1_CL1;
     } else {
         mask_obj = TB_LOW_PWR_C1_PORT_A_MASK;
         unmask_obj = TB_LOW_PWR_C0_PORT_B_MASK;
         offset = TB_LOW_PWR_C3_CL1;
     }
 
     ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
              sw->cap_lp + offset, ARRAY_SIZE(val));
     if (ret)
         return ret;
 
     for (i = 0; i < ARRAY_SIZE(val); i++) {
         val[i] |= mask_obj;
         val[i] &= ~unmask_obj;
     }
 
     return tb_sw_write(sw, &val, TB_CFG_SWITCH,
                sw->cap_lp + offset, ARRAY_SIZE(val));
 }
 
 /*
  * 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");
     }
 }