[POWERPC] Disable PCI IO/Mem on a device when resources can't be allocated

This patch changes the PowerPC PCI code to disable IO and/or Memory
decoding on a PCI device when a resource of that type failed to be
allocated.  This is done to avoid having unallocated dangling BARs
enabled that might try to decode on top of other devices.

If a proper resource is assigned later on, then pci_enable_device()
will take care of re-enabling decoding.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 1037b3a093eecc6ae808851295343bda43d44a32..88838b0f8b90b90d86d40f3f2199a59a79f7637f 100644 (file)
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1034,7 +1034,7 @@ clear_resource:
        }
 }
 
-static inline void __devinit alloc_resource(struct pci_dev *dev, int idx)
+static inline int __devinit alloc_resource(struct pci_dev *dev, int idx)
 {
        struct resource *pr, *r = &dev->resource[idx];
 
@@ -1058,7 +1058,10 @@ static inline void __devinit alloc_resource(struct pci_dev *dev, int idx)
                r->flags |= IORESOURCE_UNSET;
                r->end -= r->start;
                r->start = 0;
+
+               return -EBUSY;
        }
+       return 0;
 }
 
 static void __init pcibios_allocate_resources(int pass)
@@ -1080,8 +1083,12 @@ static void __init pcibios_allocate_resources(int pass)
                                disabled = !(command & PCI_COMMAND_IO);
                        else
                                disabled = !(command & PCI_COMMAND_MEMORY);
-                       if (pass == disabled)
-                               alloc_resource(dev, idx);
+                       if (pass == disabled && alloc_resource(dev, idx)) {
+                               command &= ~(r->flags & (IORESOURCE_IO |
+                                                        IORESOURCE_MEM));
+                               pci_write_config_word(dev,
+                                                     PCI_COMMAND, command);
+                       }
                }
                if (pass)
                        continue;