diff options
author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2010-03-12 03:01:09 +0300 |
---|---|---|
committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2010-03-23 23:33:50 +0300 |
commit | 66f1207bce10fd80ee8ce99b67d617644612f05e (patch) | |
tree | 3031bb74dce8c54af69dcd4aa7e566f40a5511ce | |
parent | 7c9e2b1c4784c6e574f69dbd904b2822f2e04d6e (diff) | |
download | linux-66f1207bce10fd80ee8ce99b67d617644612f05e.tar.xz |
resources: add interfaces that return conflict information
request_resource() and insert_resource() only return success or failure,
which no information about what existing resource conflicted with the
proposed new reservation. This patch adds request_resource_conflict()
and insert_resource_conflict(), which return the conflicting resource.
Callers may use this for better error messages or to adjust the new
resource and retry the request.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r-- | include/linux/ioport.h | 2 | ||||
-rw-r--r-- | kernel/resource.c | 44 |
2 files changed, 39 insertions, 7 deletions
diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 71ab79da7e7f..26fad187d661 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -112,12 +112,14 @@ struct resource_list { extern struct resource ioport_resource; extern struct resource iomem_resource; +extern struct resource *request_resource_conflict(struct resource *root, struct resource *new); extern int request_resource(struct resource *root, struct resource *new); extern int release_resource(struct resource *new); void release_child_resources(struct resource *new); extern void reserve_region_with_split(struct resource *root, resource_size_t start, resource_size_t end, const char *name); +extern struct resource *insert_resource_conflict(struct resource *parent, struct resource *new); extern int insert_resource(struct resource *parent, struct resource *new); extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new); extern int allocate_resource(struct resource *root, struct resource *new, diff --git a/kernel/resource.c b/kernel/resource.c index 2d5be5d9bf5f..9c358e263534 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -219,19 +219,34 @@ void release_child_resources(struct resource *r) } /** - * request_resource - request and reserve an I/O or memory resource + * request_resource_conflict - request and reserve an I/O or memory resource * @root: root resource descriptor * @new: resource descriptor desired by caller * - * Returns 0 for success, negative error code on error. + * Returns 0 for success, conflict resource on error. */ -int request_resource(struct resource *root, struct resource *new) +struct resource *request_resource_conflict(struct resource *root, struct resource *new) { struct resource *conflict; write_lock(&resource_lock); conflict = __request_resource(root, new); write_unlock(&resource_lock); + return conflict; +} + +/** + * request_resource - request and reserve an I/O or memory resource + * @root: root resource descriptor + * @new: resource descriptor desired by caller + * + * Returns 0 for success, negative error code on error. + */ +int request_resource(struct resource *root, struct resource *new) +{ + struct resource *conflict; + + conflict = request_resource_conflict(root, new); return conflict ? -EBUSY : 0; } @@ -474,25 +489,40 @@ static struct resource * __insert_resource(struct resource *parent, struct resou } /** - * insert_resource - Inserts a resource in the resource tree + * insert_resource_conflict - Inserts resource in the resource tree * @parent: parent of the new resource * @new: new resource to insert * - * Returns 0 on success, -EBUSY if the resource can't be inserted. + * Returns 0 on success, conflict resource if the resource can't be inserted. * - * This function is equivalent to request_resource when no conflict + * This function is equivalent to request_resource_conflict when no conflict * happens. If a conflict happens, and the conflicting resources * entirely fit within the range of the new resource, then the new * resource is inserted and the conflicting resources become children of * the new resource. */ -int insert_resource(struct resource *parent, struct resource *new) +struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) { struct resource *conflict; write_lock(&resource_lock); conflict = __insert_resource(parent, new); write_unlock(&resource_lock); + return conflict; +} + +/** + * insert_resource - Inserts a resource in the resource tree + * @parent: parent of the new resource + * @new: new resource to insert + * + * Returns 0 on success, -EBUSY if the resource can't be inserted. + */ +int insert_resource(struct resource *parent, struct resource *new) +{ + struct resource *conflict; + + conflict = insert_resource_conflict(parent, new); return conflict ? -EBUSY : 0; } |