diff options
author | Toshi Kani <toshi.kani@hpe.com> | 2016-03-09 20:47:04 +0100 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2016-03-09 20:07:20 +0100 |
commit | ff3cc952d3f009e6c376cc40651b87187ce364a6 (patch) | |
tree | c0b685a62ea8908bfdab98dc372bfe75fd0f291e /kernel/resource.c | |
parent | resource: Change __request_region to inherit from immediate parent (diff) | |
download | linux-ff3cc952d3f009e6c376cc40651b87187ce364a6.tar.xz linux-ff3cc952d3f009e6c376cc40651b87187ce364a6.zip |
resource: Add remove_resource interface
insert_resource() and insert_resource_conflict() are called
by resource producers to insert a new resource. When there
is any conflict, they move conflicting resources down to the
children of the new resource. There is no destructor of these
interfaces, however.
Add remove_resource(), which removes a resource previously
inserted by insert_resource() or insert_resource_conflict(),
and moves the children up to where they were before.
__release_resource() is changed to have @release_child, so
that this function can be used for remove_resource() as well.
Also add comments to clarify that these functions are intended
for producers of resources to avoid any confusion with
request/release_resource() for consumers.
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'kernel/resource.c')
-rw-r--r-- | kernel/resource.c | 51 |
1 files changed, 46 insertions, 5 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 5a56e8f24058..effb6ee2c3e8 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -233,9 +233,9 @@ static struct resource * __request_resource(struct resource *root, struct resour } } -static int __release_resource(struct resource *old) +static int __release_resource(struct resource *old, bool release_child) { - struct resource *tmp, **p; + struct resource *tmp, **p, *chd; p = &old->parent->child; for (;;) { @@ -243,7 +243,17 @@ static int __release_resource(struct resource *old) if (!tmp) break; if (tmp == old) { - *p = tmp->sibling; + if (release_child || !(tmp->child)) { + *p = tmp->sibling; + } else { + for (chd = tmp->child;; chd = chd->sibling) { + chd->parent = tmp->parent; + if (!(chd->sibling)) + break; + } + *p = tmp->child; + chd->sibling = tmp->sibling; + } old->parent = NULL; return 0; } @@ -325,7 +335,7 @@ int release_resource(struct resource *old) int retval; write_lock(&resource_lock); - retval = __release_resource(old); + retval = __release_resource(old, true); write_unlock(&resource_lock); return retval; } @@ -679,7 +689,7 @@ static int reallocate_resource(struct resource *root, struct resource *old, old->start = new.start; old->end = new.end; } else { - __release_resource(old); + __release_resource(old, true); *old = new; conflict = __request_resource(root, old); BUG_ON(conflict); @@ -825,6 +835,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou * 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. + * + * This function is intended for producers of resources, such as FW modules + * and bus drivers. */ struct resource *insert_resource_conflict(struct resource *parent, struct resource *new) { @@ -842,6 +855,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour * @new: new resource to insert * * Returns 0 on success, -EBUSY if the resource can't be inserted. + * + * This function is intended for producers of resources, such as FW modules + * and bus drivers. */ int insert_resource(struct resource *parent, struct resource *new) { @@ -885,6 +901,31 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new) write_unlock(&resource_lock); } +/** + * remove_resource - Remove a resource in the resource tree + * @old: resource to remove + * + * Returns 0 on success, -EINVAL if the resource is not valid. + * + * This function removes a resource previously inserted by insert_resource() + * or insert_resource_conflict(), and moves the children (if any) up to + * where they were before. insert_resource() and insert_resource_conflict() + * insert a new resource, and move any conflicting resources down to the + * children of the new resource. + * + * insert_resource(), insert_resource_conflict() and remove_resource() are + * intended for producers of resources, such as FW modules and bus drivers. + */ +int remove_resource(struct resource *old) +{ + int retval; + + write_lock(&resource_lock); + retval = __release_resource(old, false); + write_unlock(&resource_lock); + return retval; +} + static int __adjust_resource(struct resource *res, resource_size_t start, resource_size_t size) { |