PCI: pciehp: second try to get big range for pcie devices

Handle the case where the slot bridge that doesn't get a pre-allocated
resource big enough to handle its child resources..  For example pcie
devices need 256M, but the bridge only gets 2M preallocated.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 50 insertions, 1 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index b19a56b8b17a..ed545f669459 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -964,12 +964,61 @@ enable_and_dump:
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 {
         struct pci_bus *parent = bridge->subordinate;
+        int tried_times = 0;
+        struct resource_list_x head, *list;
         int retval;
+        unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                  IORESOURCE_PREFETCH;
+
+        head.next = NULL;
 
+again:
         pci_bus_size_bridges(parent);
-        __pci_bridge_assign_resources(bridge, NULL);
+        __pci_bridge_assign_resources(bridge, &head);
         retval = pci_reenable_device(bridge);
         pci_set_master(bridge);
         pci_enable_bridges(parent);
+
+        tried_times++;
+
+        if (!head.next)
+                return;
+
+        if (tried_times >= 2) {
+                /* still fail, don't need to try more */
+                free_failed_list(&head);
+                return;
+        }
+
+        printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
+                         tried_times + 1);
+
+        /*
+         * Try to release leaf bridge's resources that doesn't fit resource of
+         * child device under that bridge
+         */
+        for (list = head.next; list;) {
+                struct pci_bus *bus = list->dev->bus;
+                unsigned long flags = list->flags;
+
+                pci_bus_release_bridge_resources(bus, flags & type_mask,
+                                                 whole_subtree);
+                list = list->next;
+        }
+        /* restore size and flags */
+        for (list = head.next; list;) {
+                struct resource *res = list->res;
+
+                res->start = list->start;
+                res->end = list->end;
+                res->flags = list->flags;
+                if (list->dev->subordinate)
+                        res->flags = 0;
+
+                list = list->next;
+        }
+        free_failed_list(&head);
+
+        goto again;
 }
 EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);