summaryrefslogtreecommitdiffstats
path: root/kernel/resource.c
diff options
context:
space:
mode:
authorToshi Kani <toshi.kani@hpe.com>2016-03-09 20:47:04 +0100
committerDan Williams <dan.j.williams@intel.com>2016-03-09 20:07:20 +0100
commitff3cc952d3f009e6c376cc40651b87187ce364a6 (patch)
treec0b685a62ea8908bfdab98dc372bfe75fd0f291e /kernel/resource.c
parentresource: Change __request_region to inherit from immediate parent (diff)
downloadlinux-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.c51
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)
{