Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

[platform/kernel/linux-starfive.git] / drivers / interconnect / core.c

diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c
index 5fac448..dfab160 100644 (file)
--- a/drivers/interconnect/core.c
+++ b/drivers/interconnect/core.c
@@ -28,6 +28,7 @@ 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)
@@ -147,6 +148,21 @@ static struct icc_node *node_find(const int id)
        return idr_find(&icc_idr, id);
 }
 
+static struct icc_node *node_find_by_name(const char *name)
+{
+       struct icc_provider *provider;
+       struct icc_node *n;
+
+       list_for_each_entry(provider, &icc_providers, provider_list) {
+               list_for_each_entry(n, &provider->nodes, node_list) {
+                       if (!strcmp(n->name, name))
+                               return n;
+               }
+       }
+
+       return NULL;
+}
+
 static struct icc_path *path_init(struct device *dev, struct icc_node *dst,
                                  ssize_t num_nodes)
 {
@@ -562,6 +578,54 @@ struct icc_path *of_icc_get(struct device *dev, const char *name)
 EXPORT_SYMBOL_GPL(of_icc_get);
 
 /**
+ * icc_get() - get a path handle between two endpoints
+ * @dev: device pointer for the consumer device
+ * @src: source node name
+ * @dst: destination node 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.
+ *
+ * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned
+ * when the API is disabled.
+ */
+struct icc_path *icc_get(struct device *dev, const char *src, const char *dst)
+{
+       struct icc_node *src_node, *dst_node;
+       struct icc_path *path = ERR_PTR(-EPROBE_DEFER);
+
+       mutex_lock(&icc_lock);
+
+       src_node = node_find_by_name(src);
+       if (!src_node) {
+               dev_err(dev, "%s: invalid src=%s\n", __func__, src);
+               goto out;
+       }
+
+       dst_node = node_find_by_name(dst);
+       if (!dst_node) {
+               dev_err(dev, "%s: invalid dst=%s\n", __func__, dst);
+               goto out;
+       }
+
+       path = path_find(dev, src_node, dst_node);
+       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_node->name, dst_node->name);
+       if (!path->name) {
+               kfree(path);
+               path = ERR_PTR(-ENOMEM);
+       }
+out:
+       mutex_unlock(&icc_lock);
+       return path;
+}
+
+/**
  * icc_set_tag() - set an optional tag on a path
  * @path: the path we want to tag
  * @tag: the tag value
@@ -631,7 +695,7 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
        if (WARN_ON(IS_ERR(path) || !path->num_nodes))
                return -EINVAL;
 
-       mutex_lock(&icc_lock);
+       mutex_lock(&icc_bw_lock);
 
        old_avg = path->reqs[0].avg_bw;
        old_peak = path->reqs[0].peak_bw;
@@ -663,7 +727,7 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
                apply_constraints(path);
        }
 
-       mutex_unlock(&icc_lock);
+       mutex_unlock(&icc_bw_lock);
 
        trace_icc_set_bw_end(path, ret);
 
@@ -872,6 +936,7 @@ void icc_node_add(struct icc_node *node, struct icc_provider *provider)
                return;
 
        mutex_lock(&icc_lock);
+       mutex_lock(&icc_bw_lock);
 
        node->provider = provider;
        list_add_tail(&node->node_list, &provider->nodes);
@@ -900,6 +965,7 @@ void icc_node_add(struct icc_node *node, struct icc_provider *provider)
        node->avg_bw = 0;
        node->peak_bw = 0;
 
+       mutex_unlock(&icc_bw_lock);
        mutex_unlock(&icc_lock);
 }
 EXPORT_SYMBOL_GPL(icc_node_add);
@@ -1025,6 +1091,7 @@ void icc_sync_state(struct device *dev)
                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");
@@ -1037,13 +1104,21 @@ void icc_sync_state(struct device *dev)
                        }
                }
        }
+       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 = of_find_node_by_path("/");
+       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);
@@ -1053,6 +1128,9 @@ static int __init icc_init(void)
                            icc_debugfs_dir, NULL, &icc_summary_fops);
        debugfs_create_file("interconnect_graph", 0444,
                            icc_debugfs_dir, NULL, &icc_graph_fops);
+
+       icc_debugfs_client_init(icc_debugfs_dir);
+
        return 0;
 }