Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1184 insertions, 0 deletions

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
new file mode 100644
index 000000000..1d9494f64
--- /dev/null
+++ b/drivers/interconnect/core.c
@@ -0,0 +1,1184 @@
+// 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 DEFINE_MUTEX(icc_bw_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 (!node)
+		return ERR_PTR(-EINVAL);
+
+	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_bw_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_bw_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);
+
+	if (!node)
+		return;
+
+	kfree(node->links);
+	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);
+	mutex_lock(&icc_bw_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_bw_lock);
+	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_init() - initialize a new interconnect provider
+ * @provider: the interconnect provider to initialize
+ *
+ * Must be called before adding nodes to the provider.
+ */
+void icc_provider_init(struct icc_provider *provider)
+{
+	WARN_ON(!provider->set);
+
+	INIT_LIST_HEAD(&provider->nodes);
+}
+EXPORT_SYMBOL_GPL(icc_provider_init);
+
+/**
+ * icc_provider_register() - register a new interconnect provider
+ * @provider: the interconnect provider to register
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+int icc_provider_register(struct icc_provider *provider)
+{
+	if (WARN_ON(!provider->xlate && !provider->xlate_extended))
+		return -EINVAL;
+
+	mutex_lock(&icc_lock);
+	list_add_tail(&provider->provider_list, &icc_providers);
+	mutex_unlock(&icc_lock);
+
+	dev_dbg(provider->dev, "interconnect provider registered\n");
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(icc_provider_register);
+
+/**
+ * icc_provider_deregister() - deregister an interconnect provider
+ * @provider: the interconnect provider to deregister
+ */
+void icc_provider_deregister(struct icc_provider *provider)
+{
+	mutex_lock(&icc_lock);
+	WARN_ON(provider->users);
+
+	list_del(&provider->provider_list);
+	mutex_unlock(&icc_lock);
+}
+EXPORT_SYMBOL_GPL(icc_provider_deregister);
+
+int icc_provider_add(struct icc_provider *provider)
+{
+	icc_provider_init(provider);
+
+	return icc_provider_register(provider);
+}
+EXPORT_SYMBOL_GPL(icc_provider_add);
+
+void icc_provider_del(struct icc_provider *provider)
+{
+	WARN_ON(!list_empty(&provider->nodes));
+
+	icc_provider_deregister(provider);
+}
+EXPORT_SYMBOL_GPL(icc_provider_del);
+
+static const struct of_device_id __maybe_unused ignore_list[] = {
+	{ .compatible = "qcom,sc7180-ipa-virt" },
+	{ .compatible = "qcom,sdx55-ipa-virt" },
+	{ .compatible = "qcom,sm8150-ipa-virt" },
+	{}
+};
+
+static int of_count_icc_providers(struct device_node *np)
+{
+	struct device_node *child;
+	int count = 0;
+
+	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);
+	mutex_lock(&icc_bw_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_bw_lock);
+	mutex_unlock(&icc_lock);
+}
+EXPORT_SYMBOL_GPL(icc_sync_state);
+
+static int __init icc_init(void)
+{
+	struct device_node *root;
+
+	/* Teach lockdep about lock ordering wrt. shrinker: */
+	fs_reclaim_acquire(GFP_KERNEL);
+	might_lock(&icc_bw_lock);
+	fs_reclaim_release(GFP_KERNEL);
+
+	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");