[PATCH 02/14] resource: add release_child_resources

From: Yinghai Lu
Date: Tue Dec 22 2009 - 18:04:02 EST


-v2: change name to release_child_resources according to Jesse
-v3: according to Linus, move release_child_resources to resource.c
also need to put the lock around them all to avoid recursive deep.
(my test case only have one level that need to be released)
-v4: seperate to another patch

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Acked-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/ioport.h | 1 +
kernel/resource.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 83aa812..23a5fd1 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 dc15686..5051617 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
--
1.6.0.2

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