It will not hold lock, so we could use it in other functions that hold the resource lock already.
-v2: according to Linus, using "bool lock" as parameter aka "conditionally take lock" is *wrong*. Signed-off-by: Yinghai Lu <ying...@kernel.org> Acked-by: Linus Torvalds <torva...@linux-foundation.org> --- kernel/resource.c | 70 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 50 insertions(+), 20 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index fed052a..67b58a5 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -619,7 +619,7 @@ static int find_resource(struct resource *root, struct resource *new, } /** - * reallocate_resource - allocate a slot in the resource tree given range & alignment. + * __reallocate_resource - allocate a slot in the resource tree given range & alignment. * The resource will be relocated if the new size cannot be reallocated in the * current location. * @@ -628,7 +628,7 @@ static int find_resource(struct resource *root, struct resource *new, * @newsize: new size of the resource descriptor * @constraint: the size and alignment constraints to be met. */ -static int reallocate_resource(struct resource *root, struct resource *old, +static int __reallocate_resource(struct resource *root, struct resource *old, resource_size_t newsize, struct resource_constraint *constraint) { @@ -636,8 +636,6 @@ static int reallocate_resource(struct resource *root, struct resource *old, struct resource new = *old; struct resource *conflict; - write_lock(&resource_lock); - if ((err = __find_resource(root, old, &new, newsize, constraint))) goto out; @@ -662,14 +660,13 @@ static int reallocate_resource(struct resource *root, struct resource *old, BUG_ON(conflict); } out: - write_unlock(&resource_lock); return err; } - /** - * allocate_resource - allocate empty slot in the resource tree given range & alignment. - * The resource will be reallocated with a new size if it was already allocated + * __allocate_resource - allocate empty slot in the resource tree given range & alignment. + * The resource will be reallocated with a new size if it was already + * allocated * @root: root resource descriptor * @new: resource descriptor desired by caller * @size: requested resource region size @@ -678,15 +675,17 @@ out: * @align: alignment requested, in bytes * @alignf: alignment function, optional, called if not NULL * @alignf_data: arbitrary data to pass to the @alignf function + * + * Caller need to hold resource_lock if needed. */ -int allocate_resource(struct resource *root, struct resource *new, - resource_size_t size, resource_size_t min, - resource_size_t max, resource_size_t align, - resource_size_t (*alignf)(void *, - const struct resource *, - resource_size_t, - resource_size_t), - void *alignf_data) +static int __allocate_resource(struct resource *root, struct resource *new, + resource_size_t size, resource_size_t min, + resource_size_t max, resource_size_t align, + resource_size_t (*alignf)(void *, + const struct resource *, + resource_size_t, + resource_size_t), + void *alignf_data) { int err; struct resource_constraint constraint; @@ -700,20 +699,51 @@ int allocate_resource(struct resource *root, struct resource *new, constraint.alignf = alignf; constraint.alignf_data = alignf_data; - if ( new->parent ) { + if (new->parent) { /* resource is already allocated, try reallocating with the new constraints */ - return reallocate_resource(root, new, size, &constraint); + return __reallocate_resource(root, new, size, &constraint); } - write_lock(&resource_lock); err = find_resource(root, new, size, &constraint); if (err >= 0 && __request_resource(root, new)) err = -EBUSY; - write_unlock(&resource_lock); + return err; } +/** + * allocate_resource - allocate empty slot in the resource tree given range & alignment. + * The resource will be reallocated with a new size if it was already + * allocated + * @root: root resource descriptor + * @new: resource descriptor desired by caller + * @size: requested resource region size + * @min: minimum boundary to allocate + * @max: maximum boundary to allocate + * @align: alignment requested, in bytes + * @alignf: alignment function, optional, called if not NULL + * @alignf_data: arbitrary data to pass to the @alignf function + */ +int allocate_resource(struct resource *root, struct resource *new, + resource_size_t size, resource_size_t min, + resource_size_t max, resource_size_t align, + resource_size_t (*alignf)(void *, + const struct resource *, + resource_size_t, + resource_size_t), + void *alignf_data) +{ + int ret; + + write_lock(&resource_lock); + ret = __allocate_resource(root, new, size, min, max, align, + alignf, alignf_data); + write_unlock(&resource_lock); + + return ret; +} + EXPORT_SYMBOL(allocate_resource); /** -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/