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devres: Make locking straight forward in release_nodes() 

It seems for the sake of saving stack memory of couple of pointers,
the locking in release_nodes() callers becomes interesting.

Replace this logic with a straight forward locking and unlocking scheme.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517122946.53161-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andy Shevchenko 2021-05-17 15:29:43 +03:00 committed by Greg Kroah-Hartman
parent d826e03651
commit bbc8f3e79e
1 changed files with 15 additions and 15 deletions
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30
drivers/base/devres.c
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@ -503,28 +503,18 @@ static int remove_nodes(struct device *dev,
return cnt;
}
static int release_nodes(struct device *dev, struct list_head *first,
struct list_head *end, unsigned long flags)
__releases(&dev->devres_lock)
static void release_nodes(struct device *dev, struct list_head *todo)
{
LIST_HEAD(todo);
int cnt;
struct devres *dr, *tmp;
cnt = remove_nodes(dev, first, end, &todo);
spin_unlock_irqrestore(&dev->devres_lock, flags);
/* Release. Note that both devres and devres_group are
* handled as devres in the following loop. This is safe.
*/
list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
list_for_each_entry_safe_reverse(dr, tmp, todo, node.entry) {
devres_log(dev, &dr->node, "REL");
dr->node.release(dev, dr->data);
kfree(dr);
}
return cnt;
}
/**
@ -537,13 +527,19 @@ static int release_nodes(struct device *dev, struct list_head *first,
int devres_release_all(struct device *dev)
{
unsigned long flags;
LIST_HEAD(todo);
int cnt;
/* Looks like an uninitialized device structure */
if (WARN_ON(dev->devres_head.next == NULL))
return -ENODEV;
spin_lock_irqsave(&dev->devres_lock, flags);
return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
flags);
cnt = remove_nodes(dev, dev->devres_head.next, &dev->devres_head, &todo);
spin_unlock_irqrestore(&dev->devres_lock, flags);
release_nodes(dev, &todo);
return cnt;
}
/**
@ -679,6 +675,7 @@ int devres_release_group(struct device *dev, void *id)
{
struct devres_group *grp;
unsigned long flags;
LIST_HEAD(todo);
int cnt = 0;
spin_lock_irqsave(&dev->devres_lock, flags);
@ -691,7 +688,10 @@ int devres_release_group(struct device *dev, void *id)
if (!list_empty(&grp->node[1].entry))
end = grp->node[1].entry.next;
cnt = release_nodes(dev, first, end, flags);
cnt = remove_nodes(dev, first, end, &todo);
spin_unlock_irqrestore(&dev->devres_lock, flags);
release_nodes(dev, &todo);
} else {
WARN_ON(1);
spin_unlock_irqrestore(&dev->devres_lock, flags);