[PATCH] Fix PCI ROM mapping

This fixes a problem with pci_map_rom() which doesn't properly
update the ROM BAR value with the address thas allocated for it by the
PCI code. This problem, among other, breaks boot on Mac laptops.

It'ss a new version based on Linus latest one with better error
checking.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 17 insertions, 7 deletions

diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index 713c78f3a65d..49bd21702314 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -21,13 +21,21 @@
  * between the ROM and other resources, so enabling it may disable access
  * to MMIO registers or other card memory.
  */
-static void pci_enable_rom(struct pci_dev *pdev)
+static int pci_enable_rom(struct pci_dev *pdev)
 {
+        struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
+        struct pci_bus_region region;
         u32 rom_addr;
 
+        if (!res->flags)
+                return -1;
+
+        pcibios_resource_to_bus(pdev, &region, res);
         pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
-        rom_addr |= PCI_ROM_ADDRESS_ENABLE;
+        rom_addr &= ~PCI_ROM_ADDRESS_MASK;
+        rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
         pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
+        return 0;
 }
 
 /**
@@ -71,19 +79,21 @@ void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
         } else {
                 if (res->flags & IORESOURCE_ROM_COPY) {
                         *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
-                        return (void __iomem *)pci_resource_start(pdev, PCI_ROM_RESOURCE);
+                        return (void __iomem *)pci_resource_start(pdev,
+                                                             PCI_ROM_RESOURCE);
                 } else {
                         /* assign the ROM an address if it doesn't have one */
-                        if (res->parent == NULL)
-                                pci_assign_resource(pdev, PCI_ROM_RESOURCE);
-
+                        if (res->parent == NULL &&
+                            pci_assign_resource(pdev,PCI_ROM_RESOURCE))
+                                return NULL;
                         start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
                         *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
                         if (*size == 0)
                                 return NULL;
 
                         /* Enable ROM space decodes */
-                        pci_enable_rom(pdev);
+                        if (pci_enable_rom(pdev))
+                                return NULL;
                 }
         }