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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 - path/tunnel functionality
  *
  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
  * Copyright (C) 2019, Intel Corporation
  */
 
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/ktime.h>
 
 #include "tb.h"
 
 static void tb_dump_hop(const struct tb_path_hop *hop, const struct tb_regs_hop *regs)
 {
     const struct tb_port *port = hop->in_port;
 
     tb_port_dbg(port, " In HopID: %d => Out port: %d Out HopID: %d\n",
             hop->in_hop_index, regs->out_port, regs->next_hop);
     tb_port_dbg(port, "  Weight: %d Priority: %d Credits: %d Drop: %d\n",
             regs->weight, regs->priority,
             regs->initial_credits, regs->drop_packages);
     tb_port_dbg(port, "   Counter enabled: %d Counter index: %d\n",
             regs->counter_enable, regs->counter);
     tb_port_dbg(port, "  Flow Control (In/Eg): %d/%d Shared Buffer (In/Eg): %d/%d\n",
             regs->ingress_fc, regs->egress_fc,
             regs->ingress_shared_buffer, regs->egress_shared_buffer);
     tb_port_dbg(port, "  Unknown1: %#x Unknown2: %#x Unknown3: %#x\n",
             regs->unknown1, regs->unknown2, regs->unknown3);
 }
 
 static struct tb_port *tb_path_find_dst_port(struct tb_port *src, int src_hopid,
                          int dst_hopid)
 {
     struct tb_port *port, *out_port = NULL;
     struct tb_regs_hop hop;
     struct tb_switch *sw;
     int i, ret, hopid;
 
     hopid = src_hopid;
     port = src;
 
     for (i = 0; port && i < TB_PATH_MAX_HOPS; i++) {
         sw = port->sw;
 
         ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hopid, 2);
         if (ret) {
             tb_port_warn(port, "failed to read path at %d\n", hopid);
             return NULL;
         }
 
         if (!hop.enable)
             return NULL;
 
         out_port = &sw->ports[hop.out_port];
         hopid = hop.next_hop;
         port = out_port->remote;
     }
 
     return out_port && hopid == dst_hopid ? out_port : NULL;
 }
 
 static int tb_path_find_src_hopid(struct tb_port *src,
     const struct tb_port *dst, int dst_hopid)
 {
     struct tb_port *out;
     int i;
 
     for (i = TB_PATH_MIN_HOPID; i <= src->config.max_in_hop_id; i++) {
         out = tb_path_find_dst_port(src, i, dst_hopid);
         if (out == dst)
             return i;
     }
 
     return 0;
 }
 
 /**
  * tb_path_discover() - Discover a path
  * @src: First input port of a path
  * @src_hopid: Starting HopID of a path (%-1 if don't care)
  * @dst: Expected destination port of the path (%NULL if don't care)
  * @dst_hopid: HopID to the @dst (%-1 if don't care)
  * @last: Last port is filled here if not %NULL
  * @name: Name of the path
  * @alloc_hopid: Allocate HopIDs for the ports
  *
  * Follows a path starting from @src and @src_hopid to the last output
  * port of the path. Allocates HopIDs for the visited ports (if
  * @alloc_hopid is true). Call tb_path_free() to release the path and
  * allocated HopIDs when the path is not needed anymore.
  *
  * Note function discovers also incomplete paths so caller should check
  * that the @dst port is the expected one. If it is not, the path can be
  * cleaned up by calling tb_path_deactivate() before tb_path_free().
  *
  * Return: Discovered path on success, %NULL in case of failure
  */
 struct tb_path *tb_path_discover(struct tb_port *src, int src_hopid,
                  struct tb_port *dst, int dst_hopid,
                  struct tb_port **last, const char *name,
                  bool alloc_hopid)
 {
     struct tb_port *out_port;
     struct tb_regs_hop hop;
     struct tb_path *path;
     struct tb_switch *sw;
     struct tb_port *p;
     size_t num_hops;
     int ret, i, h;
 
     if (src_hopid < 0 && dst) {
         /*
          * For incomplete paths the intermediate HopID can be
          * different from the one used by the protocol adapter
          * so in that case find a path that ends on @dst with
          * matching @dst_hopid. That should give us the correct
          * HopID for the @src.
          */
         src_hopid = tb_path_find_src_hopid(src, dst, dst_hopid);
         if (!src_hopid)
             return NULL;
     }
 
     p = src;
     h = src_hopid;
     num_hops = 0;
 
     for (i = 0; p && i < TB_PATH_MAX_HOPS; i++) {
         sw = p->sw;
 
         ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
         if (ret) {
             tb_port_warn(p, "failed to read path at %d\n", h);
             return NULL;
         }
 
         /* If the hop is not enabled we got an incomplete path */
         if (!hop.enable)
             break;
 
         out_port = &sw->ports[hop.out_port];
         if (last)
             *last = out_port;
 
         h = hop.next_hop;
         p = out_port->remote;
         num_hops++;
     }
 
     path = kzalloc(sizeof(*path), GFP_KERNEL);
     if (!path)
         return NULL;
 
     path->name = name;
     path->tb = src->sw->tb;
     path->path_length = num_hops;
     path->activated = true;
     path->alloc_hopid = alloc_hopid;
 
     path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
     if (!path->hops) {
         kfree(path);
         return NULL;
     }
 
     tb_dbg(path->tb, "discovering %s path starting from %llx:%u\n",
            path->name, tb_route(src->sw), src->port);
 
     p = src;
     h = src_hopid;
 
     for (i = 0; i < num_hops; i++) {
         int next_hop;
 
         sw = p->sw;
 
         ret = tb_port_read(p, &hop, TB_CFG_HOPS, 2 * h, 2);
         if (ret) {
             tb_port_warn(p, "failed to read path at %d\n", h);
             goto err;
         }
 
         if (alloc_hopid && tb_port_alloc_in_hopid(p, h, h) < 0)
             goto err;
 
         out_port = &sw->ports[hop.out_port];
         next_hop = hop.next_hop;
 
         if (alloc_hopid &&
             tb_port_alloc_out_hopid(out_port, next_hop, next_hop) < 0) {
             tb_port_release_in_hopid(p, h);
             goto err;
         }
 
         path->hops[i].in_port = p;
         path->hops[i].in_hop_index = h;
         path->hops[i].in_counter_index = -1;
         path->hops[i].out_port = out_port;
         path->hops[i].next_hop_index = next_hop;
 
         tb_dump_hop(&path->hops[i], &hop);
 
         h = next_hop;
         p = out_port->remote;
     }
 
     tb_dbg(path->tb, "path discovery complete\n");
     return path;
 
 err:
     tb_port_warn(src, "failed to discover path starting at HopID %d\n",
              src_hopid);
     tb_path_free(path);
     return NULL;
 }
 
 /**
  * tb_path_alloc() - allocate a thunderbolt path between two ports
  * @tb: Domain pointer
  * @src: Source port of the path
  * @src_hopid: HopID used for the first ingress port in the path
  * @dst: Destination port of the path
  * @dst_hopid: HopID used for the last egress port in the path
  * @link_nr: Preferred link if there are dual links on the path
  * @name: Name of the path
  *
  * Creates path between two ports starting with given @src_hopid. Reserves
  * HopIDs for each port (they can be different from @src_hopid depending on
  * how many HopIDs each port already have reserved). If there are dual
  * links on the path, prioritizes using @link_nr but takes into account
  * that the lanes may be bonded.
  *
  * Return: Returns a tb_path on success or NULL on failure.
  */
 struct tb_path *tb_path_alloc(struct tb *tb, struct tb_port *src, int src_hopid,
                   struct tb_port *dst, int dst_hopid, int link_nr,
                   const char *name)
 {
     struct tb_port *in_port, *out_port, *first_port, *last_port;
     int in_hopid, out_hopid;
     struct tb_path *path;
     size_t num_hops;
     int i, ret;
 
     path = kzalloc(sizeof(*path), GFP_KERNEL);
     if (!path)
         return NULL;
 
     first_port = last_port = NULL;
     i = 0;
     tb_for_each_port_on_path(src, dst, in_port) {
         if (!first_port)
             first_port = in_port;
         last_port = in_port;
         i++;
     }
 
     /* Check that src and dst are reachable */
     if (first_port != src || last_port != dst) {
         kfree(path);
         return NULL;
     }
 
     /* Each hop takes two ports */
     num_hops = i / 2;
 
     path->hops = kcalloc(num_hops, sizeof(*path->hops), GFP_KERNEL);
     if (!path->hops) {
         kfree(path);
         return NULL;
     }
 
     path->alloc_hopid = true;
 
     in_hopid = src_hopid;
     out_port = NULL;
 
     for (i = 0; i < num_hops; i++) {
         in_port = tb_next_port_on_path(src, dst, out_port);
         if (!in_port)
             goto err;
 
         /* When lanes are bonded primary link must be used */
         if (!in_port->bonded && in_port->dual_link_port &&
             in_port->link_nr != link_nr)
             in_port = in_port->dual_link_port;
 
         ret = tb_port_alloc_in_hopid(in_port, in_hopid, in_hopid);
         if (ret < 0)
             goto err;
         in_hopid = ret;
 
         out_port = tb_next_port_on_path(src, dst, in_port);
         if (!out_port)
             goto err;
 
         /*
          * Pick up right port when going from non-bonded to
          * bonded or from bonded to non-bonded.
          */
         if (out_port->dual_link_port) {
             if (!in_port->bonded && out_port->bonded &&
                 out_port->link_nr) {
                 /*
                  * Use primary link when going from
                  * non-bonded to bonded.
                  */
                 out_port = out_port->dual_link_port;
             } else if (!out_port->bonded &&
                    out_port->link_nr != link_nr) {
                 /*
                  * If out port is not bonded follow
                  * link_nr.
                  */
                 out_port = out_port->dual_link_port;
             }
         }
 
         if (i == num_hops - 1)
             ret = tb_port_alloc_out_hopid(out_port, dst_hopid,
                               dst_hopid);
         else
             ret = tb_port_alloc_out_hopid(out_port, -1, -1);
 
         if (ret < 0)
             goto err;
         out_hopid = ret;
 
         path->hops[i].in_hop_index = in_hopid;
         path->hops[i].in_port = in_port;
         path->hops[i].in_counter_index = -1;
         path->hops[i].out_port = out_port;
         path->hops[i].next_hop_index = out_hopid;
 
         in_hopid = out_hopid;
     }
 
     path->tb = tb;
     path->path_length = num_hops;
     path->name = name;
 
     return path;
 
 err:
     tb_path_free(path);
     return NULL;
 }
 
 /**
  * tb_path_free() - free a path
  * @path: Path to free
  *
  * Frees a path. The path does not need to be deactivated.
  */
 void tb_path_free(struct tb_path *path)
 {
     if (path->alloc_hopid) {
         int i;
 
         for (i = 0; i < path->path_length; i++) {
             const struct tb_path_hop *hop = &path->hops[i];
 
             if (hop->in_port)
                 tb_port_release_in_hopid(hop->in_port,
                              hop->in_hop_index);
             if (hop->out_port)
                 tb_port_release_out_hopid(hop->out_port,
                               hop->next_hop_index);
         }
     }
 
     kfree(path->hops);
     kfree(path);
 }
 
 static void __tb_path_deallocate_nfc(struct tb_path *path, int first_hop)
 {
     int i, res;
     for (i = first_hop; i < path->path_length; i++) {
         res = tb_port_add_nfc_credits(path->hops[i].in_port,
                           -path->hops[i].nfc_credits);
         if (res)
             tb_port_warn(path->hops[i].in_port,
                      "nfc credits deallocation failed for hop %d\n",
                      i);
     }
 }
 
 static int __tb_path_deactivate_hop(struct tb_port *port, int hop_index,
                     bool clear_fc)
 {
     struct tb_regs_hop hop;
     ktime_t timeout;
     int ret;
 
     /* Disable the path */
     ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
     if (ret)
         return ret;
 
     /* Already disabled */
     if (!hop.enable)
         return 0;
 
     hop.enable = 0;
 
     ret = tb_port_write(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
     if (ret)
         return ret;
 
     /* Wait until it is drained */
     timeout = ktime_add_ms(ktime_get(), 500);
     do {
         ret = tb_port_read(port, &hop, TB_CFG_HOPS, 2 * hop_index, 2);
         if (ret)
             return ret;
 
         if (!hop.pending) {
             if (clear_fc) {
                 /*
                  * Clear flow control. Protocol adapters
                  * IFC and ISE bits are vendor defined
                  * in the USB4 spec so we clear them
                  * only for pre-USB4 adapters.
                  */
                 if (!tb_switch_is_usb4(port->sw)) {
                     hop.ingress_fc = 0;
                     hop.ingress_shared_buffer = 0;
                 }
                 hop.egress_fc = 0;
                 hop.egress_shared_buffer = 0;
 
                 return tb_port_write(port, &hop, TB_CFG_HOPS,
                              2 * hop_index, 2);
             }
 
             return 0;
         }
 
         usleep_range(10, 20);
     } while (ktime_before(ktime_get(), timeout));
 
     return -ETIMEDOUT;
 }
 
 static void __tb_path_deactivate_hops(struct tb_path *path, int first_hop)
 {
     int i, res;
 
     for (i = first_hop; i < path->path_length; i++) {
         res = __tb_path_deactivate_hop(path->hops[i].in_port,
                            path->hops[i].in_hop_index,
                            path->clear_fc);
         if (res && res != -ENODEV)
             tb_port_warn(path->hops[i].in_port,
                      "hop deactivation failed for hop %d, index %d\n",
                      i, path->hops[i].in_hop_index);
     }
 }
 
 void tb_path_deactivate(struct tb_path *path)
 {
     if (!path->activated) {
         tb_WARN(path->tb, "trying to deactivate an inactive path\n");
         return;
     }
     tb_dbg(path->tb,
            "deactivating %s path from %llx:%u to %llx:%u\n",
            path->name, tb_route(path->hops[0].in_port->sw),
            path->hops[0].in_port->port,
            tb_route(path->hops[path->path_length - 1].out_port->sw),
            path->hops[path->path_length - 1].out_port->port);
     __tb_path_deactivate_hops(path, 0);
     __tb_path_deallocate_nfc(path, 0);
     path->activated = false;
 }
 
 /**
  * tb_path_activate() - activate a path
  * @path: Path to activate
  *
  * Activate a path starting with the last hop and iterating backwards. The
  * caller must fill path->hops before calling tb_path_activate().
  *
  * Return: Returns 0 on success or an error code on failure.
  */
 int tb_path_activate(struct tb_path *path)
 {
     int i, res;
     enum tb_path_port out_mask, in_mask;
     if (path->activated) {
         tb_WARN(path->tb, "trying to activate already activated path\n");
         return -EINVAL;
     }
 
     tb_dbg(path->tb,
            "activating %s path from %llx:%u to %llx:%u\n",
            path->name, tb_route(path->hops[0].in_port->sw),
            path->hops[0].in_port->port,
            tb_route(path->hops[path->path_length - 1].out_port->sw),
            path->hops[path->path_length - 1].out_port->port);
 
     /* Clear counters. */
     for (i = path->path_length - 1; i >= 0; i--) {
         if (path->hops[i].in_counter_index == -1)
             continue;
         res = tb_port_clear_counter(path->hops[i].in_port,
                         path->hops[i].in_counter_index);
         if (res)
             goto err;
     }
 
     /* Add non flow controlled credits. */
     for (i = path->path_length - 1; i >= 0; i--) {
         res = tb_port_add_nfc_credits(path->hops[i].in_port,
                           path->hops[i].nfc_credits);
         if (res) {
             __tb_path_deallocate_nfc(path, i);
             goto err;
         }
     }
 
     /* Activate hops. */
     for (i = path->path_length - 1; i >= 0; i--) {
         struct tb_regs_hop hop = { 0 };
 
         /* If it is left active deactivate it first */
         __tb_path_deactivate_hop(path->hops[i].in_port,
                 path->hops[i].in_hop_index, path->clear_fc);
 
         /* dword 0 */
         hop.next_hop = path->hops[i].next_hop_index;
         hop.out_port = path->hops[i].out_port->port;
         hop.initial_credits = path->hops[i].initial_credits;
         hop.unknown1 = 0;
         hop.enable = 1;
 
         /* dword 1 */
         out_mask = (i == path->path_length - 1) ?
                 TB_PATH_DESTINATION : TB_PATH_INTERNAL;
         in_mask = (i == 0) ? TB_PATH_SOURCE : TB_PATH_INTERNAL;
         hop.weight = path->weight;
         hop.unknown2 = 0;
         hop.priority = path->priority;
         hop.drop_packages = path->drop_packages;
         hop.counter = path->hops[i].in_counter_index;
         hop.counter_enable = path->hops[i].in_counter_index != -1;
         hop.ingress_fc = path->ingress_fc_enable & in_mask;
         hop.egress_fc = path->egress_fc_enable & out_mask;
         hop.ingress_shared_buffer = path->ingress_shared_buffer
                         & in_mask;
         hop.egress_shared_buffer = path->egress_shared_buffer
                         & out_mask;
         hop.unknown3 = 0;
 
         tb_port_dbg(path->hops[i].in_port, "Writing hop %d\n", i);
         tb_dump_hop(&path->hops[i], &hop);
         res = tb_port_write(path->hops[i].in_port, &hop, TB_CFG_HOPS,
                     2 * path->hops[i].in_hop_index, 2);
         if (res) {
             __tb_path_deactivate_hops(path, i);
             __tb_path_deallocate_nfc(path, 0);
             goto err;
         }
     }
     path->activated = true;
     tb_dbg(path->tb, "path activation complete\n");
     return 0;
 err:
     tb_WARN(path->tb, "path activation failed\n");
     return res;
 }
 
 /**
  * tb_path_is_invalid() - check whether any ports on the path are invalid
  * @path: Path to check
  *
  * Return: Returns true if the path is invalid, false otherwise.
  */
 bool tb_path_is_invalid(struct tb_path *path)
 {
     int i = 0;
     for (i = 0; i < path->path_length; i++) {
         if (path->hops[i].in_port->sw->is_unplugged)
             return true;
         if (path->hops[i].out_port->sw->is_unplugged)
             return true;
     }
     return false;
 }
 
 /**
  * tb_path_port_on_path() - Does the path go through certain port
  * @path: Path to check
  * @port: Switch to check
  *
  * Goes over all hops on path and checks if @port is any of them.
  * Direction does not matter.
  */
 bool tb_path_port_on_path(const struct tb_path *path, const struct tb_port *port)
 {
     int i;
 
     for (i = 0; i < path->path_length; i++) {
         if (path->hops[i].in_port == port ||
             path->hops[i].out_port == port)
             return true;
     }
 
     return false;
 }

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