diff options
Diffstat (limited to 'kernel/resource.c')
| -rw-r--r-- | kernel/resource.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/kernel/resource.c b/kernel/resource.c index 3ff40178dce..c8dc249da5c 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -419,6 +419,9 @@ static int __find_resource(struct resource *root, struct resource *old, else tmp.end = root->end; + if (tmp.end < tmp.start) + goto next; + resource_clip(&tmp, constraint->min, constraint->max); arch_remove_reservations(&tmp); @@ -436,8 +439,10 @@ static int __find_resource(struct resource *root, struct resource *old, return 0; } } - if (!this) + +next: if (!this || this->end == root->end) break; + if (this != old) tmp.start = this->end + 1; this = this->sibling; @@ -553,6 +558,27 @@ int allocate_resource(struct resource *root, struct resource *new, EXPORT_SYMBOL(allocate_resource); +/** + * lookup_resource - find an existing resource by a resource start address + * @root: root resource descriptor + * @start: resource start address + * + * Returns a pointer to the resource if found, NULL otherwise + */ +struct resource *lookup_resource(struct resource *root, resource_size_t start) +{ + struct resource *res; + + read_lock(&resource_lock); + for (res = root->child; res; res = res->sibling) { + if (res->start == start) + break; + } + read_unlock(&resource_lock); + + return res; +} + /* * Insert a resource into the resource tree. If successful, return NULL, * otherwise return the conflicting resource (compare to __request_resource()) |