resources: Add lookup_resource()

Add a function to find an existing resource by a resource start address.
This allows to implement simple allocators (with a malloc/free-alike API)
on top of the resource system.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index e9bb22cba764..63eb429ecbe6 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -132,6 +132,7 @@ extern int allocate_resource(struct resource *root, struct resource *new,
                                                        resource_size_t,
                                                        resource_size_t),
                              void *alignf_data);
+struct resource *lookup_resource(struct resource *root, resource_size_t start);
 int adjust_resource(struct resource *res, resource_size_t start,
                     resource_size_t size);
 resource_size_t resource_alignment(struct resource *res);