Merge branch 'component' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

Pull component updates from Russell King:
 "Updates for the component helper merged last year.

  This update removes the old add_components method of detecting and
  looking up the components associated with a master device.  Last time
  I checked during the 4.4-rc cycle, there were no users of the old
  interfaces, as has been the case for some time now.  Breakage due to
  conflicting development is possible, in which case this pull will have
  to be reverted - however, these changes have been in linux-next since
  Dec 7th without any problems reported.

  Removal of that then allows us to change the way we track components
  internally, allowing us to release data that has been used for
  matching at the appropriate time, thereby allowing any resource leaks
  caused by that missing functionality to be resolved"

* 'component' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  component: add support for releasing match data
  component: track components via array rather than list
  component: move check for unbound master into try_to_bring_up_masters()
  component: remove old add_components method

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