[PATCH RFC v2 8/8] component: track components via array rather than list
Russell King
rmk+kernel at arm.linux.org.uk
Tue Jun 24 12:29:33 PDT 2014
Since we now have an array which defines each component, maintain the
components to be bound in the array rather than a separate list. We
also need duplicate tracking so we can eliminate multiple bind calls
for the same component: we preserve the list-based component order in
that the first match which adds the component determines its position.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/base/component.c | 140 +++++++++++++++++++++--------------------------
1 file changed, 62 insertions(+), 78 deletions(-)
diff --git a/drivers/base/component.c b/drivers/base/component.c
index 0863cfeea769..8a1d784a9759 100644
--- a/drivers/base/component.c
+++ b/drivers/base/component.c
@@ -18,18 +18,21 @@
#include <linux/mutex.h>
#include <linux/slab.h>
+struct component;
+
struct component_match {
size_t alloc;
size_t num;
struct {
void *data;
int (*fn)(struct device *, void *);
+ struct component *component;
+ bool duplicate;
} compare[0];
};
struct master {
struct list_head node;
- struct list_head components;
bool bound;
const struct component_master_ops *ops;
@@ -39,7 +42,6 @@ struct master {
struct component {
struct list_head node;
- struct list_head master_node;
struct master *master;
bool bound;
@@ -63,46 +65,20 @@ 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.
- */
-static 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;
}
static int find_components(struct master *master)
@@ -116,26 +92,35 @@ static int find_components(struct master *master)
* 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 *c;
+
+ if (match->compare[i].component)
+ continue;
+
+ c = find_component(master, match->compare[i].fn,
+ match->compare[i].data);
+ if (!c) {
+ ret = -ENXIO;
break;
+ }
+
+ /* 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;
}
/*
@@ -150,37 +135,25 @@ static int try_to_bring_up_master(struct master *master,
{
int ret;
- if (find_components(master)) {
- /* Failed to find all components */
- ret = 0;
- goto out;
- }
+ if (find_components(master))
+ return 0;
- if (component && component->master != master) {
- ret = 0;
- goto out;
- }
+ if (component && component->master != master)
+ 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)
@@ -206,8 +179,6 @@ static void take_down_master(struct master *master)
devres_release_group(master->dev, NULL);
master->bound = false;
}
-
- master_remove_components(master);
}
static size_t component_match_size(size_t num)
@@ -265,6 +236,7 @@ void component_match_add(struct device *dev, struct component_match **matchptr,
match->compare[match->num].fn = compare;
match->compare[match->num].data = compare_data;
+ match->compare[match->num].component = NULL;
match->num++;
}
@@ -287,7 +259,6 @@ 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);
@@ -339,6 +310,7 @@ 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));
@@ -346,8 +318,12 @@ 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);
@@ -407,6 +383,7 @@ 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));
@@ -415,16 +392,21 @@ 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;
@@ -472,8 +454,10 @@ 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);
--
1.8.3.1
More information about the linux-arm-kernel
mailing list