From 5eeec0ec931a01e85b3701ce121b7d8a1800ec60 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 22 Dec 2009 15:02:22 -0800 Subject: resource: add release_child_resources Useful for freeing a portion of the resource tree, e.g. when trying to reallocate resources more efficiently. Signed-off-by: Yinghai Lu Acked-by: Linus Torvalds Signed-off-by: Jesse Barnes --- include/linux/ioport.h | 1 + kernel/resource.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 4a811891dbe3..dda98410d588 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -112,6 +112,7 @@ extern struct resource iomem_resource; 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); diff --git a/kernel/resource.c b/kernel/resource.c index 7fd123ad00aa..24e9e60c1459 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -188,6 +188,36 @@ static int __release_resource(struct resource *old) return -EINVAL; } +static void __release_child_resources(struct resource *r) +{ + struct resource *tmp, *p; + resource_size_t size; + + p = r->child; + r->child = NULL; + while (p) { + tmp = p; + p = p->sibling; + + tmp->parent = NULL; + tmp->sibling = NULL; + __release_child_resources(tmp); + + printk(KERN_DEBUG "release child resource %pR\n", tmp); + /* need to restore size, and keep flags */ + size = resource_size(tmp); + tmp->start = 0; + tmp->end = size - 1; + } +} + +void release_child_resources(struct resource *r) +{ + write_lock(&resource_lock); + __release_child_resources(r); + write_unlock(&resource_lock); +} + /** * request_resource - request and reserve an I/O or memory resource * @root: root resource descriptor -- cgit v1.2.3