| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Georgi Djakov | 2921 | 99.90% | 7 | 87.50% |
| Yangtao Li | 3 | 0.10% | 1 | 12.50% |
| Total | 2924 | 8 |
// 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> static DEFINE_IDR(icc_idr); static LIST_HEAD(icc_providers); static DEFINE_MUTEX(icc_lock); static struct dentry *icc_debugfs_dir; /** * struct icc_req - constraints that are attached to each node * @req_node: entry in list of requests for the particular @node * @node: the interconnect node to which this constraint applies * @dev: reference to the device that sets the constraints * @tag: path tag (optional) * @avg_bw: an integer describing the average bandwidth in kBps * @peak_bw: an integer describing the peak bandwidth in kBps */ struct icc_req { struct hlist_node req_node; struct icc_node *node; struct device *dev; u32 tag; u32 avg_bw; u32 peak_bw; }; /** * struct icc_path - interconnect path structure * @num_nodes: number of hops (nodes) * @reqs: array of the requests applicable to this path of nodes */ struct icc_path { size_t num_nodes; struct icc_req reqs[]; }; static void icc_summary_show_one(struct seq_file *s, struct icc_node *n) { if (!n) return; seq_printf(s, "%-30s %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 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) { if (!r->dev) continue; seq_printf(s, " %-26s %12u %12u\n", dev_name(r->dev), r->avg_bw, r->peak_bw); } } } mutex_unlock(&icc_lock); return 0; } DEFINE_SHOW_ATTRIBUTE(icc_summary); 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; /* 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; 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) p->aggregate(node, r->tag, r->avg_bw, r->peak_bw, &node->avg_bw, &node->peak_bw); return 0; } static int apply_constraints(struct icc_path *path) { struct icc_node *next, *prev = NULL; int ret = -EINVAL; int i; for (i = 0; i < path->num_nodes; i++) { next = path->reqs[i].node; /* * Both endpoints should be valid master-slave pairs of the * same interconnect provider that will be configured. */ if (!prev || next->provider != prev->provider) { prev = next; continue; } /* set the constraints */ ret = next->provider->set(prev, next); if (ret) goto out; prev = next; } out: return ret; } /* 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 on success or ERR_PTR() * on failure. */ static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec) { struct icc_node *node = ERR_PTR(-EPROBE_DEFER); struct icc_provider *provider; if (!spec || spec->args_count != 1) return ERR_PTR(-EINVAL); mutex_lock(&icc_lock); list_for_each_entry(provider, &icc_providers, provider_list) { if (provider->dev->of_node == spec->np) node = provider->xlate(spec, provider->data); if (!IS_ERR(node)) break; } mutex_unlock(&icc_lock); return node; } /** * 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 icc_path *path = ERR_PTR(-EPROBE_DEFER); struct icc_node *src_node, *dst_node; struct device_node *np = NULL; struct of_phandle_args src_args, dst_args; int idx = 0; 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. */ if (name) { idx = of_property_match_string(np, "interconnect-names", name); if (idx < 0) return ERR_PTR(idx); } 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_node = of_icc_get_from_provider(&src_args); if (IS_ERR(src_node)) { if (PTR_ERR(src_node) != -EPROBE_DEFER) dev_err(dev, "error finding src node: %ld\n", PTR_ERR(src_node)); return ERR_CAST(src_node); } dst_node = of_icc_get_from_provider(&dst_args); if (IS_ERR(dst_node)) { if (PTR_ERR(dst_node) != -EPROBE_DEFER) dev_err(dev, "error finding dst node: %ld\n", PTR_ERR(dst_node)); return ERR_CAST(dst_node); } mutex_lock(&icc_lock); path = path_find(dev, src_node, dst_node); if (IS_ERR(path)) dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); mutex_unlock(&icc_lock); return path; } 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_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 || !path->num_nodes) return 0; 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); } 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); return ret; } EXPORT_SYMBOL_GPL(icc_set_bw); /** * 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)); 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(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; 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) { mutex_lock(&icc_lock); node->provider = provider; list_add_tail(&node->node_list, &provider->nodes); 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_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)) 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 __init icc_init(void) { icc_debugfs_dir = debugfs_create_dir("interconnect", NULL); debugfs_create_file("interconnect_summary", 0444, icc_debugfs_dir, NULL, &icc_summary_fops); return 0; } static void __exit icc_exit(void) { debugfs_remove_recursive(icc_debugfs_dir); } module_init(icc_init); module_exit(icc_exit); MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); MODULE_DESCRIPTION("Interconnect Driver Core"); MODULE_LICENSE("GPL v2");
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