resource: Add resource_contains()

We have two identical copies of resource_contains() already, and more
places that could use it.  This moves it to ioport.h where it can be
shared.

resource_contains(struct resource *r1, struct resource *r2) returns true
iff r1 and r2 are the same type (most callers already checked this
separately) and the r1 address range completely contains r2.

In addition, the new resource_contains() checks that both r1 and r2 have
addresses assigned to them.  If a resource is IORESOURCE_UNSET, it doesn't
have a valid address and can't contain or be contained by another resource.
Some callers already check this or for res->start.

No functional change.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host-bridge.c

@@ -32,11 +32,6 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 	bridge->release_data = release_data;
 }
 
-static bool resource_contains(struct resource *res1, struct resource *res2)
-{
-	return res1->start <= res2->start && res1->end >= res2->end;
-}
-
 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 			     struct resource *res)
 {
@@ -45,9 +40,6 @@ void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 	resource_size_t offset = 0;
 
 	list_for_each_entry(window, &bridge->windows, list) {
-		if (resource_type(res) != resource_type(window->res))
-			continue;
-
 		if (resource_contains(window->res, res)) {
 			offset = window->offset;
 			break;

include/linux/ioport.h

@@ -169,6 +169,16 @@ static inline unsigned long resource_type(const struct resource *res)
 {
 	return res->flags & IORESOURCE_TYPE_BITS;
 }
+/* True iff r1 completely contains r2 */
+static inline bool resource_contains(struct resource *r1, struct resource *r2)
+{
+	if (resource_type(r1) != resource_type(r2))
+		return false;
+	if (r1->flags & IORESOURCE_UNSET || r2->flags & IORESOURCE_UNSET)
+		return false;
+	return r1->start <= r2->start && r1->end >= r2->end;
+}
+
 
 /* Convenience shorthand with allocation */
 #define request_region(start,n,name)		__request_region(&ioport_resource, (start), (n), (name), 0)

kernel/resource.c

@@ -432,11 +432,6 @@ static void resource_clip(struct resource *res, resource_size_t min,
 		res->end = max;
 }
 
-static bool resource_contains(struct resource *res1, struct resource *res2)
-{
-	return res1->start <= res2->start && res1->end >= res2->end;
-}
-
 /*
  * Find empty slot in the resource tree with the given range and
  * alignment constraints
@@ -471,10 +466,11 @@ static int __find_resource(struct resource *root, struct resource *old,
 		arch_remove_reservations(&tmp);
 
 		/* Check for overflow after ALIGN() */
-		avail = *new;
 		avail.start = ALIGN(tmp.start, constraint->align);
 		avail.end = tmp.end;
+		avail.flags = new->flags & ~IORESOURCE_UNSET;
 		if (avail.start >= tmp.start) {
+			alloc.flags = avail.flags;
 			alloc.start = constraint->alignf(constraint->alignf_data, &avail,
 					size, constraint->align);
 			alloc.end = alloc.start + size - 1;