1 files changed, 56 insertions, 0 deletions
diff --git a/target/linux/lantiq/patches-3.0/995-backport-3.1-lookup_resource.patch b/target/linux/lantiq/patches-3.0/995-backport-3.1-lookup_resource.patch
new file mode 100644
index 0000000000..76c7135c09
--- /dev/null
+++ b/target/linux/lantiq/patches-3.0/995-backport-3.1-lookup_resource.patch
@@ -0,0 +1,56 @@
+commit 1c388919d89ca35741e9c4d3255adf87f76f0c06
+Author: Geert Uytterhoeven <geert@linux-m68k.org>
+Date:   Sat May 7 20:53:16 2011 +0200
+
+    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>
+
+diff --git a/include/linux/ioport.h b/include/linux/ioport.h
+index e9bb22c..63eb429 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);
+diff --git a/kernel/resource.c b/kernel/resource.c
+index 3ff4017..3b3cedc 100644
+--- a/kernel/resource.c
++++ b/kernel/resource.c
+@@ -553,6 +553,27 @@ 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())