@@ -64,6 +64,49 @@ void pci_bus_remove_resources(struct pci_bus *bus)
}
}
+/*
+ * Find the highest-address bus resource below the cursor "res". If the
+ * cursor is NULL, return the highest resource.
+ */
+static struct resource *pci_bus_find_resource_prev(struct pci_bus *bus,
+ unsigned int type,
+ struct resource *res)
+{
+ struct resource *r, *prev = NULL;
+ int i;
+
+ pci_bus_for_each_resource(bus, r, i) {
+ if (!r)
+ continue;
+
+ if ((r->flags & IORESOURCE_TYPE_BITS) != type)
+ continue;
+
+ /* If this resource is at or past the cursor, skip it */
+ if (res) {
+ if (r == res)
+ continue;
+ if (r->end > res->end)
+ continue;
+ if (r->end == res->end && r->start > res->start)
+ continue;
+ }
+
+ if (!prev)
+ prev = r;
+
+ /*
+ * A small resource is higher than a large one that ends at
+ * the same address.
+ */
+ if (r->end > prev->end ||
+ (r->end == prev->end && r->start > prev->start))
+ prev = r;
+ }
+
+ return prev;
+}
+
/**
* pci_bus_alloc_resource - allocate a resource from a parent bus
* @bus: PCI bus
@@ -89,9 +132,10 @@ pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
resource_size_t),
void *alignf_data)
{
- int i, ret = -ENOMEM;
+ int ret = -ENOMEM;
struct resource *r;
resource_size_t max = -1;
+ unsigned int type = res->flags & IORESOURCE_TYPE_BITS;
type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
@@ -99,10 +143,9 @@ pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
if (!(res->flags & IORESOURCE_MEM_64))
max = PCIBIOS_MAX_MEM_32;
- pci_bus_for_each_resource(bus, r, i) {
- if (!r)
- continue;
-
+ /* Look for space at highest addresses first */
+ r = pci_bus_find_resource_prev(bus, type, NULL);
+ for ( ; r; r = pci_bus_find_resource_prev(bus, type, r)) {
/* type_mask must match */
if ((res->flags ^ r->flags) & type_mask)
continue;