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-rw-r--r--kernel/resource.c49
1 files changed, 32 insertions, 17 deletions
diff --git a/kernel/resource.c b/kernel/resource.c
index d22423e85cf8..7ea4306503c5 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -326,7 +326,7 @@ EXPORT_SYMBOL(release_resource);
*
* If a resource is found, returns 0 and @*res is overwritten with the part
* of the resource that's within [@start..@end]; if none is found, returns
- * -1 or -EINVAL for other invalid parameters.
+ * -ENODEV. Returns -EINVAL for invalid parameters.
*
* This function walks the whole tree and not just first level children
* unless @first_lvl is true.
@@ -342,6 +342,7 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
unsigned long flags, unsigned long desc,
bool first_lvl, struct resource *res)
{
+ bool siblings_only = true;
struct resource *p;
if (!res)
@@ -352,29 +353,43 @@ static int find_next_iomem_res(resource_size_t start, resource_size_t end,
read_lock(&resource_lock);
- for (p = iomem_resource.child; p; p = next_resource(p, first_lvl)) {
- if ((p->flags & flags) != flags)
- continue;
- if ((desc != IORES_DESC_NONE) && (desc != p->desc))
- continue;
+ for (p = iomem_resource.child; p; p = next_resource(p, siblings_only)) {
+ /* If we passed the resource we are looking for, stop */
if (p->start > end) {
p = NULL;
break;
}
- if ((p->end >= start) && (p->start <= end))
- break;
+
+ /* Skip until we find a range that matches what we look for */
+ if (p->end < start)
+ continue;
+
+ /*
+ * Now that we found a range that matches what we look for,
+ * check the flags and the descriptor. If we were not asked to
+ * use only the first level, start looking at children as well.
+ */
+ siblings_only = first_lvl;
+
+ if ((p->flags & flags) != flags)
+ continue;
+ if ((desc != IORES_DESC_NONE) && (desc != p->desc))
+ continue;
+
+ /* Found a match, break */
+ break;
+ }
+
+ if (p) {
+ /* copy data */
+ res->start = max(start, p->start);
+ res->end = min(end, p->end);
+ res->flags = p->flags;
+ res->desc = p->desc;
}
read_unlock(&resource_lock);
- if (!p)
- return -1;
-
- /* copy data */
- res->start = max(start, p->start);
- res->end = min(end, p->end);
- res->flags = p->flags;
- res->desc = p->desc;
- return 0;
+ return p ? 0 : -ENODEV;
}
static int __walk_iomem_res_desc(resource_size_t start, resource_size_t end,