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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
 /*
  * Interconnect framework core driver
  *
  * Copyright (c) 2017-2019, Linaro Ltd.
  * Author: Georgi Djakov <georgi.djakov@linaro.org>
  */
 
 #include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/interconnect.h>
 #include <linux/interconnect-provider.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/overflow.h>
 
 #include "internal.h"
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
 
 static DEFINE_IDR(icc_idr);
 static LIST_HEAD(icc_providers);
 static int providers_count;
 static bool synced_state;
 static DEFINE_MUTEX(icc_lock);
 static struct dentry *icc_debugfs_dir;
 
 static void icc_summary_show_one(struct seq_file *s, struct icc_node *n)
 {
     if (!n)
         return;
 
     seq_printf(s, "%-42s %12u %12u\n",
            n->name, n->avg_bw, n->peak_bw);
 }
 
 static int icc_summary_show(struct seq_file *s, void *data)
 {
     struct icc_provider *provider;
 
     seq_puts(s, " node                                  tag          avg         peak\n");
     seq_puts(s, "--------------------------------------------------------------------\n");
 
     mutex_lock(&icc_lock);
 
     list_for_each_entry(provider, &icc_providers, provider_list) {
         struct icc_node *n;
 
         list_for_each_entry(n, &provider->nodes, node_list) {
             struct icc_req *r;
 
             icc_summary_show_one(s, n);
             hlist_for_each_entry(r, &n->req_list, req_node) {
                 u32 avg_bw = 0, peak_bw = 0;
 
                 if (!r->dev)
                     continue;
 
                 if (r->enabled) {
                     avg_bw = r->avg_bw;
                     peak_bw = r->peak_bw;
                 }
 
                 seq_printf(s, "  %-27s %12u %12u %12u\n",
                        dev_name(r->dev), r->tag, avg_bw, peak_bw);
             }
         }
     }
 
     mutex_unlock(&icc_lock);
 
     return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(icc_summary);
 
 static void icc_graph_show_link(struct seq_file *s, int level,
                 struct icc_node *n, struct icc_node *m)
 {
     seq_printf(s, "%s\"%d:%s\" -> \"%d:%s\"\n",
            level == 2 ? "\t\t" : "\t",
            n->id, n->name, m->id, m->name);
 }
 
 static void icc_graph_show_node(struct seq_file *s, struct icc_node *n)
 {
     seq_printf(s, "\t\t\"%d:%s\" [label=\"%d:%s",
            n->id, n->name, n->id, n->name);
     seq_printf(s, "\n\t\t\t|avg_bw=%ukBps", n->avg_bw);
     seq_printf(s, "\n\t\t\t|peak_bw=%ukBps", n->peak_bw);
     seq_puts(s, "\"]\n");
 }
 
 static int icc_graph_show(struct seq_file *s, void *data)
 {
     struct icc_provider *provider;
     struct icc_node *n;
     int cluster_index = 0;
     int i;
 
     seq_puts(s, "digraph {\n\trankdir = LR\n\tnode [shape = record]\n");
     mutex_lock(&icc_lock);
 
     /* draw providers as cluster subgraphs */
     cluster_index = 0;
     list_for_each_entry(provider, &icc_providers, provider_list) {
         seq_printf(s, "\tsubgraph cluster_%d {\n", ++cluster_index);
         if (provider->dev)
             seq_printf(s, "\t\tlabel = \"%s\"\n",
                    dev_name(provider->dev));
 
         /* draw nodes */
         list_for_each_entry(n, &provider->nodes, node_list)
             icc_graph_show_node(s, n);
 
         /* draw internal links */
         list_for_each_entry(n, &provider->nodes, node_list)
             for (i = 0; i < n->num_links; ++i)
                 if (n->provider == n->links[i]->provider)
                     icc_graph_show_link(s, 2, n,
                                 n->links[i]);
 
         seq_puts(s, "\t}\n");
     }
 
     /* draw external links */
     list_for_each_entry(provider, &icc_providers, provider_list)
         list_for_each_entry(n, &provider->nodes, node_list)
             for (i = 0; i < n->num_links; ++i)
                 if (n->provider != n->links[i]->provider)
                     icc_graph_show_link(s, 1, n,
                                 n->links[i]);
 
     mutex_unlock(&icc_lock);
     seq_puts(s, "}");
 
     return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(icc_graph);
 
 static struct icc_node *node_find(const int id)
 {
     return idr_find(&icc_idr, id);
 }
 
 static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
                   ssize_t num_nodes)
 {
     struct icc_node *node = dst;
     struct icc_path *path;
     int i;
 
     path = kzalloc(struct_size(path, reqs, num_nodes), GFP_KERNEL);
     if (!path)
         return ERR_PTR(-ENOMEM);
 
     path->num_nodes = num_nodes;
 
     for (i = num_nodes - 1; i >= 0; i--) {
         node->provider->users++;
         hlist_add_head(&path->reqs[i].req_node, &node->req_list);
         path->reqs[i].node = node;
         path->reqs[i].dev = dev;
         path->reqs[i].enabled = true;
         /* reference to previous node was saved during path traversal */
         node = node->reverse;
     }
 
     return path;
 }
 
 static struct icc_path *path_find(struct device *dev, struct icc_node *src,
                   struct icc_node *dst)
 {
     struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
     struct icc_node *n, *node = NULL;
     struct list_head traverse_list;
     struct list_head edge_list;
     struct list_head visited_list;
     size_t i, depth = 1;
     bool found = false;
 
     INIT_LIST_HEAD(&traverse_list);
     INIT_LIST_HEAD(&edge_list);
     INIT_LIST_HEAD(&visited_list);
 
     list_add(&src->search_list, &traverse_list);
     src->reverse = NULL;
 
     do {
         list_for_each_entry_safe(node, n, &traverse_list, search_list) {
             if (node == dst) {
                 found = true;
                 list_splice_init(&edge_list, &visited_list);
                 list_splice_init(&traverse_list, &visited_list);
                 break;
             }
             for (i = 0; i < node->num_links; i++) {
                 struct icc_node *tmp = node->links[i];
 
                 if (!tmp) {
                     path = ERR_PTR(-ENOENT);
                     goto out;
                 }
 
                 if (tmp->is_traversed)
                     continue;
 
                 tmp->is_traversed = true;
                 tmp->reverse = node;
                 list_add_tail(&tmp->search_list, &edge_list);
             }
         }
 
         if (found)
             break;
 
         list_splice_init(&traverse_list, &visited_list);
         list_splice_init(&edge_list, &traverse_list);
 
         /* count the hops including the source */
         depth++;
 
     } while (!list_empty(&traverse_list));
 
 out:
 
     /* reset the traversed state */
     list_for_each_entry_reverse(n, &visited_list, search_list)
         n->is_traversed = false;
 
     if (found)
         path = path_init(dev, dst, depth);
 
     return path;
 }
 
 /*
  * We want the path to honor all bandwidth requests, so the average and peak
  * bandwidth requirements from each consumer are aggregated at each node.
  * The aggregation is platform specific, so each platform can customize it by
  * implementing its own aggregate() function.
  */
 
 static int aggregate_requests(struct icc_node *node)
 {
     struct icc_provider *p = node->provider;
     struct icc_req *r;
     u32 avg_bw, peak_bw;
 
     node->avg_bw = 0;
     node->peak_bw = 0;
 
     if (p->pre_aggregate)
         p->pre_aggregate(node);
 
     hlist_for_each_entry(r, &node->req_list, req_node) {
         if (r->enabled) {
             avg_bw = r->avg_bw;
             peak_bw = r->peak_bw;
         } else {
             avg_bw = 0;
             peak_bw = 0;
         }
         p->aggregate(node, r->tag, avg_bw, peak_bw,
                  &node->avg_bw, &node->peak_bw);
 
         /* during boot use the initial bandwidth as a floor value */
         if (!synced_state) {
             node->avg_bw = max(node->avg_bw, node->init_avg);
             node->peak_bw = max(node->peak_bw, node->init_peak);
         }
     }
 
     return 0;
 }
 
 static int apply_constraints(struct icc_path *path)
 {
     struct icc_node *next, *prev = NULL;
     struct icc_provider *p;
     int ret = -EINVAL;
     int i;
 
     for (i = 0; i < path->num_nodes; i++) {
         next = path->reqs[i].node;
         p = next->provider;
 
         /* both endpoints should be valid master-slave pairs */
         if (!prev || (p != prev->provider && !p->inter_set)) {
             prev = next;
             continue;
         }
 
         /* set the constraints */
         ret = p->set(prev, next);
         if (ret)
             goto out;
 
         prev = next;
     }
 out:
     return ret;
 }
 
 int icc_std_aggregate(struct icc_node *node, u32 tag, u32 avg_bw,
               u32 peak_bw, u32 *agg_avg, u32 *agg_peak)
 {
     *agg_avg += avg_bw;
     *agg_peak = max(*agg_peak, peak_bw);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(icc_std_aggregate);
 
 /* of_icc_xlate_onecell() - Translate function using a single index.
  * @spec: OF phandle args to map into an interconnect node.
  * @data: private data (pointer to struct icc_onecell_data)
  *
  * This is a generic translate function that can be used to model simple
  * interconnect providers that have one device tree node and provide
  * multiple interconnect nodes. A single cell is used as an index into
  * an array of icc nodes specified in the icc_onecell_data struct when
  * registering the provider.
  */
 struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec,
                       void *data)
 {
     struct icc_onecell_data *icc_data = data;
     unsigned int idx = spec->args[0];
 
     if (idx >= icc_data->num_nodes) {
         pr_err("%s: invalid index %u\n", __func__, idx);
         return ERR_PTR(-EINVAL);
     }
 
     return icc_data->nodes[idx];
 }
 EXPORT_SYMBOL_GPL(of_icc_xlate_onecell);
 
 /**
  * of_icc_get_from_provider() - Look-up interconnect node
  * @spec: OF phandle args to use for look-up
  *
  * Looks for interconnect provider under the node specified by @spec and if
  * found, uses xlate function of the provider to map phandle args to node.
  *
  * Returns a valid pointer to struct icc_node_data on success or ERR_PTR()
  * on failure.
  */
 struct icc_node_data *of_icc_get_from_provider(struct of_phandle_args *spec)
 {
     struct icc_node *node = ERR_PTR(-EPROBE_DEFER);
     struct icc_node_data *data = NULL;
     struct icc_provider *provider;
 
     if (!spec)
         return ERR_PTR(-EINVAL);
 
     mutex_lock(&icc_lock);
     list_for_each_entry(provider, &icc_providers, provider_list) {
         if (provider->dev->of_node == spec->np) {
             if (provider->xlate_extended) {
                 data = provider->xlate_extended(spec, provider->data);
                 if (!IS_ERR(data)) {
                     node = data->node;
                     break;
                 }
             } else {
                 node = provider->xlate(spec, provider->data);
                 if (!IS_ERR(node))
                     break;
             }
         }
     }
     mutex_unlock(&icc_lock);
 
     if (IS_ERR(node))
         return ERR_CAST(node);
 
     if (!data) {
         data = kzalloc(sizeof(*data), GFP_KERNEL);
         if (!data)
             return ERR_PTR(-ENOMEM);
         data->node = node;
     }
 
     return data;
 }
 EXPORT_SYMBOL_GPL(of_icc_get_from_provider);
 
 static void devm_icc_release(struct device *dev, void *res)
 {
     icc_put(*(struct icc_path **)res);
 }
 
 struct icc_path *devm_of_icc_get(struct device *dev, const char *name)
 {
     struct icc_path **ptr, *path;
 
     ptr = devres_alloc(devm_icc_release, sizeof(*ptr), GFP_KERNEL);
     if (!ptr)
         return ERR_PTR(-ENOMEM);
 
     path = of_icc_get(dev, name);
     if (!IS_ERR(path)) {
         *ptr = path;
         devres_add(dev, ptr);
     } else {
         devres_free(ptr);
     }
 
     return path;
 }
 EXPORT_SYMBOL_GPL(devm_of_icc_get);
 
 /**
  * of_icc_get_by_index() - get a path handle from a DT node based on index
  * @dev: device pointer for the consumer device
  * @idx: interconnect path index
  *
  * This function will search for a path between two endpoints and return an
  * icc_path handle on success. Use icc_put() to release constraints when they
  * are not needed anymore.
  * If the interconnect API is disabled, NULL is returned and the consumer
  * drivers will still build. Drivers are free to handle this specifically,
  * but they don't have to.
  *
  * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
  * when the API is disabled or the "interconnects" DT property is missing.
  */
 struct icc_path *of_icc_get_by_index(struct device *dev, int idx)
 {
     struct icc_path *path;
     struct icc_node_data *src_data, *dst_data;
     struct device_node *np;
     struct of_phandle_args src_args, dst_args;
     int ret;
 
     if (!dev || !dev->of_node)
         return ERR_PTR(-ENODEV);
 
     np = dev->of_node;
 
     /*
      * When the consumer DT node do not have "interconnects" property
      * return a NULL path to skip setting constraints.
      */
     if (!of_find_property(np, "interconnects", NULL))
         return NULL;
 
     /*
      * We use a combination of phandle and specifier for endpoint. For now
      * lets support only global ids and extend this in the future if needed
      * without breaking DT compatibility.
      */
     ret = of_parse_phandle_with_args(np, "interconnects",
                      "#interconnect-cells", idx * 2,
                      &src_args);
     if (ret)
         return ERR_PTR(ret);
 
     of_node_put(src_args.np);
 
     ret = of_parse_phandle_with_args(np, "interconnects",
                      "#interconnect-cells", idx * 2 + 1,
                      &dst_args);
     if (ret)
         return ERR_PTR(ret);
 
     of_node_put(dst_args.np);
 
     src_data = of_icc_get_from_provider(&src_args);
 
     if (IS_ERR(src_data)) {
         dev_err_probe(dev, PTR_ERR(src_data), "error finding src node\n");
         return ERR_CAST(src_data);
     }
 
     dst_data = of_icc_get_from_provider(&dst_args);
 
     if (IS_ERR(dst_data)) {
         dev_err_probe(dev, PTR_ERR(dst_data), "error finding dst node\n");
         kfree(src_data);
         return ERR_CAST(dst_data);
     }
 
     mutex_lock(&icc_lock);
     path = path_find(dev, src_data->node, dst_data->node);
     mutex_unlock(&icc_lock);
     if (IS_ERR(path)) {
         dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
         goto free_icc_data;
     }
 
     if (src_data->tag && src_data->tag == dst_data->tag)
         icc_set_tag(path, src_data->tag);
 
     path->name = kasprintf(GFP_KERNEL, "%s-%s",
                    src_data->node->name, dst_data->node->name);
     if (!path->name) {
         kfree(path);
         path = ERR_PTR(-ENOMEM);
     }
 
 free_icc_data:
     kfree(src_data);
     kfree(dst_data);
     return path;
 }
 EXPORT_SYMBOL_GPL(of_icc_get_by_index);
 
 /**
  * of_icc_get() - get a path handle from a DT node based on name
  * @dev: device pointer for the consumer device
  * @name: interconnect path name
  *
  * This function will search for a path between two endpoints and return an
  * icc_path handle on success. Use icc_put() to release constraints when they
  * are not needed anymore.
  * If the interconnect API is disabled, NULL is returned and the consumer
  * drivers will still build. Drivers are free to handle this specifically,
  * but they don't have to.
  *
  * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
  * when the API is disabled or the "interconnects" DT property is missing.
  */
 struct icc_path *of_icc_get(struct device *dev, const char *name)
 {
     struct device_node *np;
     int idx = 0;
 
     if (!dev || !dev->of_node)
         return ERR_PTR(-ENODEV);
 
     np = dev->of_node;
 
     /*
      * When the consumer DT node do not have "interconnects" property
      * return a NULL path to skip setting constraints.
      */
     if (!of_find_property(np, "interconnects", NULL))
         return NULL;
 
     /*
      * We use a combination of phandle and specifier for endpoint. For now
      * lets support only global ids and extend this in the future if needed
      * without breaking DT compatibility.
      */
     if (name) {
         idx = of_property_match_string(np, "interconnect-names", name);
         if (idx < 0)
             return ERR_PTR(idx);
     }
 
     return of_icc_get_by_index(dev, idx);
 }
 EXPORT_SYMBOL_GPL(of_icc_get);
 
 /**
  * icc_set_tag() - set an optional tag on a path
  * @path: the path we want to tag
  * @tag: the tag value
  *
  * This function allows consumers to append a tag to the requests associated
  * with a path, so that a different aggregation could be done based on this tag.
  */
 void icc_set_tag(struct icc_path *path, u32 tag)
 {
     int i;
 
     if (!path)
         return;
 
     mutex_lock(&icc_lock);
 
     for (i = 0; i < path->num_nodes; i++)
         path->reqs[i].tag = tag;
 
     mutex_unlock(&icc_lock);
 }
 EXPORT_SYMBOL_GPL(icc_set_tag);
 
 /**
  * icc_get_name() - Get name of the icc path
  * @path: reference to the path returned by icc_get()
  *
  * This function is used by an interconnect consumer to get the name of the icc
  * path.
  *
  * Returns a valid pointer on success, or NULL otherwise.
  */
 const char *icc_get_name(struct icc_path *path)
 {
     if (!path)
         return NULL;
 
     return path->name;
 }
 EXPORT_SYMBOL_GPL(icc_get_name);
 
 /**
  * icc_set_bw() - set bandwidth constraints on an interconnect path
  * @path: reference to the path returned by icc_get()
  * @avg_bw: average bandwidth in kilobytes per second
  * @peak_bw: peak bandwidth in kilobytes per second
  *
  * This function is used by an interconnect consumer to express its own needs
  * in terms of bandwidth for a previously requested path between two endpoints.
  * The requests are aggregated and each node is updated accordingly. The entire
  * path is locked by a mutex to ensure that the set() is completed.
  * The @path can be NULL when the "interconnects" DT properties is missing,
  * which will mean that no constraints will be set.
  *
  * Returns 0 on success, or an appropriate error code otherwise.
  */
 int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 {
     struct icc_node *node;
     u32 old_avg, old_peak;
     size_t i;
     int ret;
 
     if (!path)
         return 0;
 
     if (WARN_ON(IS_ERR(path) || !path->num_nodes))
         return -EINVAL;
 
     mutex_lock(&icc_lock);
 
     old_avg = path->reqs[0].avg_bw;
     old_peak = path->reqs[0].peak_bw;
 
     for (i = 0; i < path->num_nodes; i++) {
         node = path->reqs[i].node;
 
         /* update the consumer request for this path */
         path->reqs[i].avg_bw = avg_bw;
         path->reqs[i].peak_bw = peak_bw;
 
         /* aggregate requests for this node */
         aggregate_requests(node);
 
         trace_icc_set_bw(path, node, i, avg_bw, peak_bw);
     }
 
     ret = apply_constraints(path);
     if (ret) {
         pr_debug("interconnect: error applying constraints (%d)\n",
              ret);
 
         for (i = 0; i < path->num_nodes; i++) {
             node = path->reqs[i].node;
             path->reqs[i].avg_bw = old_avg;
             path->reqs[i].peak_bw = old_peak;
             aggregate_requests(node);
         }
         apply_constraints(path);
     }
 
     mutex_unlock(&icc_lock);
 
     trace_icc_set_bw_end(path, ret);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(icc_set_bw);
 
 static int __icc_enable(struct icc_path *path, bool enable)
 {
     int i;
 
     if (!path)
         return 0;
 
     if (WARN_ON(IS_ERR(path) || !path->num_nodes))
         return -EINVAL;
 
     mutex_lock(&icc_lock);
 
     for (i = 0; i < path->num_nodes; i++)
         path->reqs[i].enabled = enable;
 
     mutex_unlock(&icc_lock);
 
     return icc_set_bw(path, path->reqs[0].avg_bw,
               path->reqs[0].peak_bw);
 }
 
 int icc_enable(struct icc_path *path)
 {
     return __icc_enable(path, true);
 }
 EXPORT_SYMBOL_GPL(icc_enable);
 
 int icc_disable(struct icc_path *path)
 {
     return __icc_enable(path, false);
 }
 EXPORT_SYMBOL_GPL(icc_disable);
 
 /**
  * icc_get() - return a handle for path between two endpoints
  * @dev: the device requesting the path
  * @src_id: source device port id
  * @dst_id: destination device port id
  *
  * This function will search for a path between two endpoints and return an
  * icc_path handle on success. Use icc_put() to release
  * constraints when they are not needed anymore.
  * If the interconnect API is disabled, NULL is returned and the consumer
  * drivers will still build. Drivers are free to handle this specifically,
  * but they don't have to.
  *
  * Return: icc_path pointer on success, ERR_PTR() on error or NULL if the
  * interconnect API is disabled.
  */
 struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id)
 {
     struct icc_node *src, *dst;
     struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
 
     mutex_lock(&icc_lock);
 
     src = node_find(src_id);
     if (!src)
         goto out;
 
     dst = node_find(dst_id);
     if (!dst)
         goto out;
 
     path = path_find(dev, src, dst);
     if (IS_ERR(path)) {
         dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path));
         goto out;
     }
 
     path->name = kasprintf(GFP_KERNEL, "%s-%s", src->name, dst->name);
     if (!path->name) {
         kfree(path);
         path = ERR_PTR(-ENOMEM);
     }
 out:
     mutex_unlock(&icc_lock);
     return path;
 }
 EXPORT_SYMBOL_GPL(icc_get);
 
 /**
  * icc_put() - release the reference to the icc_path
  * @path: interconnect path
  *
  * Use this function to release the constraints on a path when the path is
  * no longer needed. The constraints will be re-aggregated.
  */
 void icc_put(struct icc_path *path)
 {
     struct icc_node *node;
     size_t i;
     int ret;
 
     if (!path || WARN_ON(IS_ERR(path)))
         return;
 
     ret = icc_set_bw(path, 0, 0);
     if (ret)
         pr_err("%s: error (%d)\n", __func__, ret);
 
     mutex_lock(&icc_lock);
     for (i = 0; i < path->num_nodes; i++) {
         node = path->reqs[i].node;
         hlist_del(&path->reqs[i].req_node);
         if (!WARN_ON(!node->provider->users))
             node->provider->users--;
     }
     mutex_unlock(&icc_lock);
 
     kfree_const(path->name);
     kfree(path);
 }
 EXPORT_SYMBOL_GPL(icc_put);
 
 static struct icc_node *icc_node_create_nolock(int id)
 {
     struct icc_node *node;
 
     /* check if node already exists */
     node = node_find(id);
     if (node)
         return node;
 
     node = kzalloc(sizeof(*node), GFP_KERNEL);
     if (!node)
         return ERR_PTR(-ENOMEM);
 
     id = idr_alloc(&icc_idr, node, id, id + 1, GFP_KERNEL);
     if (id < 0) {
         WARN(1, "%s: couldn't get idr\n", __func__);
         kfree(node);
         return ERR_PTR(id);
     }
 
     node->id = id;
 
     return node;
 }
 
 /**
  * icc_node_create() - create a node
  * @id: node id
  *
  * Return: icc_node pointer on success, or ERR_PTR() on error
  */
 struct icc_node *icc_node_create(int id)
 {
     struct icc_node *node;
 
     mutex_lock(&icc_lock);
 
     node = icc_node_create_nolock(id);
 
     mutex_unlock(&icc_lock);
 
     return node;
 }
 EXPORT_SYMBOL_GPL(icc_node_create);
 
 /**
  * icc_node_destroy() - destroy a node
  * @id: node id
  */
 void icc_node_destroy(int id)
 {
     struct icc_node *node;
 
     mutex_lock(&icc_lock);
 
     node = node_find(id);
     if (node) {
         idr_remove(&icc_idr, node->id);
         WARN_ON(!hlist_empty(&node->req_list));
     }
 
     mutex_unlock(&icc_lock);
 
     kfree(node);
 }
 EXPORT_SYMBOL_GPL(icc_node_destroy);
 
 /**
  * icc_link_create() - create a link between two nodes
  * @node: source node id
  * @dst_id: destination node id
  *
  * Create a link between two nodes. The nodes might belong to different
  * interconnect providers and the @dst_id node might not exist (if the
  * provider driver has not probed yet). So just create the @dst_id node
  * and when the actual provider driver is probed, the rest of the node
  * data is filled.
  *
  * Return: 0 on success, or an error code otherwise
  */
 int icc_link_create(struct icc_node *node, const int dst_id)
 {
     struct icc_node *dst;
     struct icc_node **new;
     int ret = 0;
 
     if (!node->provider)
         return -EINVAL;
 
     mutex_lock(&icc_lock);
 
     dst = node_find(dst_id);
     if (!dst) {
         dst = icc_node_create_nolock(dst_id);
 
         if (IS_ERR(dst)) {
             ret = PTR_ERR(dst);
             goto out;
         }
     }
 
     new = krealloc(node->links,
                (node->num_links + 1) * sizeof(*node->links),
                GFP_KERNEL);
     if (!new) {
         ret = -ENOMEM;
         goto out;
     }
 
     node->links = new;
     node->links[node->num_links++] = dst;
 
 out:
     mutex_unlock(&icc_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(icc_link_create);
 
 /**
  * icc_link_destroy() - destroy a link between two nodes
  * @src: pointer to source node
  * @dst: pointer to destination node
  *
  * Return: 0 on success, or an error code otherwise
  */
 int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
 {
     struct icc_node **new;
     size_t slot;
     int ret = 0;
 
     if (IS_ERR_OR_NULL(src))
         return -EINVAL;
 
     if (IS_ERR_OR_NULL(dst))
         return -EINVAL;
 
     mutex_lock(&icc_lock);
 
     for (slot = 0; slot < src->num_links; slot++)
         if (src->links[slot] == dst)
             break;
 
     if (WARN_ON(slot == src->num_links)) {
         ret = -ENXIO;
         goto out;
     }
 
     src->links[slot] = src->links[--src->num_links];
 
     new = krealloc(src->links, src->num_links * sizeof(*src->links),
                GFP_KERNEL);
     if (new)
         src->links = new;
     else
         ret = -ENOMEM;
 
 out:
     mutex_unlock(&icc_lock);
 
     return ret;
 }
 EXPORT_SYMBOL_GPL(icc_link_destroy);
 
 /**
  * icc_node_add() - add interconnect node to interconnect provider
  * @node: pointer to the interconnect node
  * @provider: pointer to the interconnect provider
  */
 void icc_node_add(struct icc_node *node, struct icc_provider *provider)
 {
     if (WARN_ON(node->provider))
         return;
 
     mutex_lock(&icc_lock);
 
     node->provider = provider;
     list_add_tail(&node->node_list, &provider->nodes);
 
     /* get the initial bandwidth values and sync them with hardware */
     if (provider->get_bw) {
         provider->get_bw(node, &node->init_avg, &node->init_peak);
     } else {
         node->init_avg = INT_MAX;
         node->init_peak = INT_MAX;
     }
     node->avg_bw = node->init_avg;
     node->peak_bw = node->init_peak;
 
     if (provider->pre_aggregate)
         provider->pre_aggregate(node);
 
     if (provider->aggregate)
         provider->aggregate(node, 0, node->init_avg, node->init_peak,
                     &node->avg_bw, &node->peak_bw);
 
     provider->set(node, node);
     node->avg_bw = 0;
     node->peak_bw = 0;
 
     mutex_unlock(&icc_lock);
 }
 EXPORT_SYMBOL_GPL(icc_node_add);
 
 /**
  * icc_node_del() - delete interconnect node from interconnect provider
  * @node: pointer to the interconnect node
  */
 void icc_node_del(struct icc_node *node)
 {
     mutex_lock(&icc_lock);
 
     list_del(&node->node_list);
 
     mutex_unlock(&icc_lock);
 }
 EXPORT_SYMBOL_GPL(icc_node_del);
 
 /**
  * icc_nodes_remove() - remove all previously added nodes from provider
  * @provider: the interconnect provider we are removing nodes from
  *
  * Return: 0 on success, or an error code otherwise
  */
 int icc_nodes_remove(struct icc_provider *provider)
 {
     struct icc_node *n, *tmp;
 
     if (WARN_ON(IS_ERR_OR_NULL(provider)))
         return -EINVAL;
 
     list_for_each_entry_safe_reverse(n, tmp, &provider->nodes, node_list) {
         icc_node_del(n);
         icc_node_destroy(n->id);
     }
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(icc_nodes_remove);
 
 /**
  * icc_provider_add() - add a new interconnect provider
  * @provider: the interconnect provider that will be added into topology
  *
  * Return: 0 on success, or an error code otherwise
  */
 int icc_provider_add(struct icc_provider *provider)
 {
     if (WARN_ON(!provider->set))
         return -EINVAL;
     if (WARN_ON(!provider->xlate && !provider->xlate_extended))
         return -EINVAL;
 
     mutex_lock(&icc_lock);
 
     INIT_LIST_HEAD(&provider->nodes);
     list_add_tail(&provider->provider_list, &icc_providers);
 
     mutex_unlock(&icc_lock);
 
     dev_dbg(provider->dev, "interconnect provider added to topology\n");
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(icc_provider_add);
 
 /**
  * icc_provider_del() - delete previously added interconnect provider
  * @provider: the interconnect provider that will be removed from topology
  *
  * Return: 0 on success, or an error code otherwise
  */
 int icc_provider_del(struct icc_provider *provider)
 {
     mutex_lock(&icc_lock);
     if (provider->users) {
         pr_warn("interconnect provider still has %d users\n",
             provider->users);
         mutex_unlock(&icc_lock);
         return -EBUSY;
     }
 
     if (!list_empty(&provider->nodes)) {
         pr_warn("interconnect provider still has nodes\n");
         mutex_unlock(&icc_lock);
         return -EBUSY;
     }
 
     list_del(&provider->provider_list);
     mutex_unlock(&icc_lock);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(icc_provider_del);
 
 static int of_count_icc_providers(struct device_node *np)
 {
     struct device_node *child;
     int count = 0;
     const struct of_device_id __maybe_unused ignore_list[] = {
         { .compatible = "qcom,sc7180-ipa-virt" },
         { .compatible = "qcom,sdx55-ipa-virt" },
         {}
     };
 
     for_each_available_child_of_node(np, child) {
         if (of_property_read_bool(child, "#interconnect-cells") &&
             likely(!of_match_node(ignore_list, child)))
             count++;
         count += of_count_icc_providers(child);
     }
 
     return count;
 }
 
 void icc_sync_state(struct device *dev)
 {
     struct icc_provider *p;
     struct icc_node *n;
     static int count;
 
     count++;
 
     if (count < providers_count)
         return;
 
     mutex_lock(&icc_lock);
     synced_state = true;
     list_for_each_entry(p, &icc_providers, provider_list) {
         dev_dbg(p->dev, "interconnect provider is in synced state\n");
         list_for_each_entry(n, &p->nodes, node_list) {
             if (n->init_avg || n->init_peak) {
                 n->init_avg = 0;
                 n->init_peak = 0;
                 aggregate_requests(n);
                 p->set(n, n);
             }
         }
     }
     mutex_unlock(&icc_lock);
 }
 EXPORT_SYMBOL_GPL(icc_sync_state);
 
 static int __init icc_init(void)
 {
     struct device_node *root = of_find_node_by_path("/");
 
     providers_count = of_count_icc_providers(root);
     of_node_put(root);
 
     icc_debugfs_dir = debugfs_create_dir("interconnect", NULL);
     debugfs_create_file("interconnect_summary", 0444,
                 icc_debugfs_dir, NULL, &icc_summary_fops);
     debugfs_create_file("interconnect_graph", 0444,
                 icc_debugfs_dir, NULL, &icc_graph_fops);
     return 0;
 }
 
 device_initcall(icc_init);
 
 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
 MODULE_DESCRIPTION("Interconnect Driver Core");
 MODULE_LICENSE("GPL v2");

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