2 files changed, 167 insertions, 147 deletions

diff --git a/drivers/base/component.c b/drivers/base/component.c
index f748430bb654..89f5cf68d80a 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -18,18 +18,24 @@
 #include <linux/mutex.h>
 #include <linux/slab.h>
 
+struct component;
+
+struct component_match_array {
+	void *data;
+	int (*compare)(struct device *, void *);
+	void (*release)(struct device *, void *);
+	struct component *component;
+	bool duplicate;
+};
+
 struct component_match {
 	size_t alloc;
 	size_t num;
-	struct {
-		void *data;
-		int (*fn)(struct device *, void *);
-	} compare[0];
+	struct component_match_array *compare;
 };
 
 struct master {
 	struct list_head node;
-	struct list_head components;
 	bool bound;
 
 	const struct component_master_ops *ops;
@@ -39,7 +45,6 @@ struct master {
 
 struct component {
 	struct list_head node;
-	struct list_head master_node;
 	struct master *master;
 	bool bound;
 
@@ -63,48 +68,21 @@ static struct master *__master_find(struct device *dev,
 	return NULL;
 }
 
-/* Attach an unattached component to a master. */
-static void component_attach_master(struct master *master, struct component *c)
-{
-	c->master = master;
-
-	list_add_tail(&c->master_node, &master->components);
-}
-
-/* Detach a component from a master. */
-static void component_detach_master(struct master *master, struct component *c)
-{
-	list_del(&c->master_node);
-
-	c->master = NULL;
-}
-
-/*
- * Add a component to a master, finding the component via the compare
- * function and compare data.  This is safe to call for duplicate matches
- * and will not result in the same component being added multiple times.
- */
-int component_master_add_child(struct master *master,
+static struct component *find_component(struct master *master,
 	int (*compare)(struct device *, void *), void *compare_data)
 {
 	struct component *c;
-	int ret = -ENXIO;
 
 	list_for_each_entry(c, &component_list, node) {
 		if (c->master && c->master != master)
 			continue;
 
-		if (compare(c->dev, compare_data)) {
-			if (!c->master)
-				component_attach_master(master, c);
-			ret = 0;
-			break;
-		}
+		if (compare(c->dev, compare_data))
+			return c;
 	}
 
-	return ret;
+	return NULL;
 }
-EXPORT_SYMBOL_GPL(component_master_add_child);
 
 static int find_components(struct master *master)
 {
@@ -112,39 +90,44 @@ static int find_components(struct master *master)
 	size_t i;
 	int ret = 0;
 
-	if (!match) {
-		/*
-		 * Search the list of components, looking for components that
-		 * belong to this master, and attach them to the master.
-		 */
-		return master->ops->add_components(master->dev, master);
-	}
-
 	/*
 	 * Scan the array of match functions and attach
 	 * any components which are found to this master.
 	 */
 	for (i = 0; i < match->num; i++) {
-		ret = component_master_add_child(master,
-						 match->compare[i].fn,
-						 match->compare[i].data);
-		if (ret)
+		struct component_match_array *mc = &match->compare[i];
+		struct component *c;
+
+		dev_dbg(master->dev, "Looking for component %zu\n", i);
+
+		if (match->compare[i].component)
+			continue;
+
+		c = find_component(master, mc->compare, mc->data);
+		if (!c) {
+			ret = -ENXIO;
 			break;
+		}
+
+		dev_dbg(master->dev, "found component %s, duplicate %u\n", dev_name(c->dev), !!c->master);
+
+		/* Attach this component to the master */
+		match->compare[i].duplicate = !!c->master;
+		match->compare[i].component = c;
+		c->master = master;
 	}
 	return ret;
 }
 
-/* Detach all attached components from this master */
-static void master_remove_components(struct master *master)
+/* Detach component from associated master */
+static void remove_component(struct master *master, struct component *c)
 {
-	while (!list_empty(&master->components)) {
-		struct component *c = list_first_entry(&master->components,
-					struct component, master_node);
-
-		WARN_ON(c->master != master);
+	size_t i;
 
-		component_detach_master(master, c);
-	}
+	/* Detach the component from this master. */
+	for (i = 0; i < master->match->num; i++)
+		if (master->match->compare[i].component == c)
+			master->match->compare[i].component = NULL;
 }
 
 /*
@@ -159,44 +142,32 @@ static int try_to_bring_up_master(struct master *master,
 {
 	int ret;
 
-	if (master->bound)
-		return 0;
+	dev_dbg(master->dev, "trying to bring up master\n");
 
-	/*
-	 * Search the list of components, looking for components that
-	 * belong to this master, and attach them to the master.
-	 */
 	if (find_components(master)) {
-		/* Failed to find all components */
-		ret = 0;
-		goto out;
+		dev_dbg(master->dev, "master has incomplete components\n");
+		return 0;
 	}
 
 	if (component && component->master != master) {
-		ret = 0;
-		goto out;
+		dev_dbg(master->dev, "master is not for this component (%s)\n",
+			dev_name(component->dev));
+		return 0;
 	}
 
-	if (!devres_open_group(master->dev, NULL, GFP_KERNEL)) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!devres_open_group(master->dev, NULL, GFP_KERNEL))
+		return -ENOMEM;
 
 	/* Found all components */
 	ret = master->ops->bind(master->dev);
 	if (ret < 0) {
 		devres_release_group(master->dev, NULL);
 		dev_info(master->dev, "master bind failed: %d\n", ret);
-		goto out;
+		return ret;
 	}
 
 	master->bound = true;
 	return 1;
-
-out:
-	master_remove_components(master);
-
-	return ret;
 }
 
 static int try_to_bring_up_masters(struct component *component)
@@ -205,9 +176,11 @@ static int try_to_bring_up_masters(struct component *component)
 	int ret = 0;
 
 	list_for_each_entry(m, &masters, node) {
-		ret = try_to_bring_up_master(m, component);
-		if (ret != 0)
-			break;
+		if (!m->bound) {
+			ret = try_to_bring_up_master(m, component);
+			if (ret != 0)
+				break;
+		}
 	}
 
 	return ret;
@@ -220,45 +193,57 @@ static void take_down_master(struct master *master)
 		devres_release_group(master->dev, NULL);
 		master->bound = false;
 	}
+}
 
-	master_remove_components(master);
+static void component_match_release(struct device *master,
+	struct component_match *match)
+{
+	unsigned int i;
+
+	for (i = 0; i < match->num; i++) {
+		struct component_match_array *mc = &match->compare[i];
+
+		if (mc->release)
+			mc->release(master, mc->data);
+	}
 }
 
-static size_t component_match_size(size_t num)
+static void devm_component_match_release(struct device *dev, void *res)
 {
-	return offsetof(struct component_match, compare[num]);
+	component_match_release(dev, res);
 }
 
-static struct component_match *component_match_realloc(struct device *dev,
+static int component_match_realloc(struct device *dev,
 	struct component_match *match, size_t num)
 {
-	struct component_match *new;
+	struct component_match_array *new;
 
-	if (match && match->alloc == num)
-		return match;
+	if (match->alloc == num)
+		return 0;
 
-	new = devm_kmalloc(dev, component_match_size(num), GFP_KERNEL);
+	new = devm_kmalloc_array(dev, num, sizeof(*new), GFP_KERNEL);
 	if (!new)
-		return ERR_PTR(-ENOMEM);
+		return -ENOMEM;
 
-	if (match) {
-		memcpy(new, match, component_match_size(min(match->num, num)));
-		devm_kfree(dev, match);
-	} else {
-		new->num = 0;
+	if (match->compare) {
+		memcpy(new, match->compare, sizeof(*new) *
+					    min(match->num, num));
+		devm_kfree(dev, match->compare);
 	}
+	match->compare = new;
+	match->alloc = num;
 
-	new->alloc = num;
-
-	return new;
+	return 0;
 }
 
 /*
- * Add a component to be matched.
+ * Add a component to be matched, with a release function.
  *
  * The match array is first created or extended if necessary.
  */
-void component_match_add(struct device *dev, struct component_match **matchptr,
+void component_match_add_release(struct device *master,
+	struct component_match **matchptr,
+	void (*release)(struct device *, void *),
 	int (*compare)(struct device *, void *), void *compare_data)
 {
 	struct component_match *match = *matchptr;
@@ -266,22 +251,37 @@ void component_match_add(struct device *dev, struct component_match **matchptr,
 	if (IS_ERR(match))
 		return;
 
-	if (!match || match->num == match->alloc) {
-		size_t new_size = match ? match->alloc + 16 : 15;
+	if (!match) {
+		match = devres_alloc(devm_component_match_release,
+				     sizeof(*match), GFP_KERNEL);
+		if (!match) {
+			*matchptr = ERR_PTR(-ENOMEM);
+			return;
+		}
 
-		match = component_match_realloc(dev, match, new_size);
+		devres_add(master, match);
 
 		*matchptr = match;
+	}
+
+	if (match->num == match->alloc) {
+		size_t new_size = match ? match->alloc + 16 : 15;
+		int ret;
 
-		if (IS_ERR(match))
+		ret = component_match_realloc(master, match, new_size);
+		if (ret) {
+			*matchptr = ERR_PTR(ret);
 			return;
+		}
 	}
 
-	match->compare[match->num].fn = compare;
+	match->compare[match->num].compare = compare;
+	match->compare[match->num].release = release;
 	match->compare[match->num].data = compare_data;
+	match->compare[match->num].component = NULL;
 	match->num++;
 }
-EXPORT_SYMBOL(component_match_add);
+EXPORT_SYMBOL(component_match_add_release);
 
 int component_master_add_with_match(struct device *dev,
 	const struct component_master_ops *ops,
@@ -290,15 +290,10 @@ int component_master_add_with_match(struct device *dev,
 	struct master *master;
 	int ret;
 
-	if (ops->add_components && match)
-		return -EINVAL;
-
-	if (match) {
-		/* Reallocate the match array for its true size */
-		match = component_match_realloc(dev, match, match->num);
-		if (IS_ERR(match))
-			return PTR_ERR(match);
-	}
+	/* Reallocate the match array for its true size */
+	ret = component_match_realloc(dev, match, match->num);
+	if (ret)
+		return ret;
 
 	master = kzalloc(sizeof(*master), GFP_KERNEL);
 	if (!master)
@@ -307,7 +302,6 @@ int component_master_add_with_match(struct device *dev,
 	master->dev = dev;
 	master->ops = ops;
 	master->match = match;
-	INIT_LIST_HEAD(&master->components);
 
 	/* Add to the list of available masters. */
 	mutex_lock(&component_mutex);
@@ -326,24 +320,28 @@ int component_master_add_with_match(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(component_master_add_with_match);
 
-int component_master_add(struct device *dev,
-	const struct component_master_ops *ops)
-{
-	return component_master_add_with_match(dev, ops, NULL);
-}
-EXPORT_SYMBOL_GPL(component_master_add);
-
 void component_master_del(struct device *dev,
 	const struct component_master_ops *ops)
 {
 	struct master *master;
+	int i;
 
 	mutex_lock(&component_mutex);
 	master = __master_find(dev, ops);
 	if (master) {
+		struct component_match *match = master->match;
+
 		take_down_master(master);
 
 		list_del(&master->node);
+
+		if (match) {
+			for (i = 0; i < match->num; i++) {
+				struct component *c = match->compare[i].component;
+				if (c)
+					c->master = NULL;
+			}
+		}
 		kfree(master);
 	}
 	mutex_unlock(&component_mutex);
@@ -366,6 +364,7 @@ void component_unbind_all(struct device *master_dev, void *data)
 {
 	struct master *master;
 	struct component *c;
+	size_t i;
 
 	WARN_ON(!mutex_is_locked(&component_mutex));
 
@@ -373,8 +372,12 @@ void component_unbind_all(struct device *master_dev, void *data)
 	if (!master)
 		return;
 
-	list_for_each_entry_reverse(c, &master->components, master_node)
-		component_unbind(c, master, data);
+	/* Unbind components in reverse order */
+	for (i = master->match->num; i--; )
+		if (!master->match->compare[i].duplicate) {
+			c = master->match->compare[i].component;
+			component_unbind(c, master, data);
+		}
 }
 EXPORT_SYMBOL_GPL(component_unbind_all);
 
@@ -434,6 +437,7 @@ int component_bind_all(struct device *master_dev, void *data)
 {
 	struct master *master;
 	struct component *c;
+	size_t i;
 	int ret = 0;
 
 	WARN_ON(!mutex_is_locked(&component_mutex));
@@ -442,16 +446,21 @@ int component_bind_all(struct device *master_dev, void *data)
 	if (!master)
 		return -EINVAL;
 
-	list_for_each_entry(c, &master->components, master_node) {
-		ret = component_bind(c, master, data);
-		if (ret)
-			break;
-	}
+	/* Bind components in match order */
+	for (i = 0; i < master->match->num; i++)
+		if (!master->match->compare[i].duplicate) {
+			c = master->match->compare[i].component;
+			ret = component_bind(c, master, data);
+			if (ret)
+				break;
+		}
 
 	if (ret != 0) {
-		list_for_each_entry_continue_reverse(c, &master->components,
-						     master_node)
-			component_unbind(c, master, data);
+		for (; i--; )
+			if (!master->match->compare[i].duplicate) {
+				c = master->match->compare[i].component;
+				component_unbind(c, master, data);
+			}
 	}
 
 	return ret;
@@ -499,8 +508,10 @@ void component_del(struct device *dev, const struct component_ops *ops)
 			break;
 		}
 
-	if (component && component->master)
+	if (component && component->master) {
 		take_down_master(component->master);
+		remove_component(component->master, component);
+	}
 
 	mutex_unlock(&component_mutex);
 
diff --git a/include/linux/component.h b/include/linux/component.h
index c00dcc302611..a559eebc0e0f 100644
--- a/include/linux/component.h
+++ b/include/linux/component.h
@@ -1,39 +1,48 @@
 #ifndef COMPONENT_H
 #define COMPONENT_H
 
+#include <linux/stddef.h>
+
 struct device;
 
 struct component_ops {
-	int (*bind)(struct device *, struct device *, void *);
-	void (*unbind)(struct device *, struct device *, void *);
+	int (*bind)(struct device *comp, struct device *master,
+		    void *master_data);
+	void (*unbind)(struct device *comp, struct device *master,
+		       void *master_data);
 };
 
 int component_add(struct device *, const struct component_ops *);
 void component_del(struct device *, const struct component_ops *);
 
-int component_bind_all(struct device *, void *);
-void component_unbind_all(struct device *, void *);
+int component_bind_all(struct device *master, void *master_data);
+void component_unbind_all(struct device *master, void *master_data);
 
 struct master;
 
 struct component_master_ops {
-	int (*add_components)(struct device *, struct master *);
-	int (*bind)(struct device *);
-	void (*unbind)(struct device *);
+	int (*bind)(struct device *master);
+	void (*unbind)(struct device *master);
 };
 
-int component_master_add(struct device *, const struct component_master_ops *);
 void component_master_del(struct device *,
 	const struct component_master_ops *);
 
-int component_master_add_child(struct master *master,
-	int (*compare)(struct device *, void *), void *compare_data);
-
 struct component_match;
 
 int component_master_add_with_match(struct device *,
 	const struct component_master_ops *, struct component_match *);
-void component_match_add(struct device *, struct component_match **,
+void component_match_add_release(struct device *master,
+	struct component_match **matchptr,
+	void (*release)(struct device *, void *),
 	int (*compare)(struct device *, void *), void *compare_data);
 
+static inline void component_match_add(struct device *master,
+	struct component_match **matchptr,
+	int (*compare)(struct device *, void *), void *compare_data)
+{
+	component_match_add_release(master, matchptr, NULL, compare,
+				    compare_data);
+}
+
 #endif