[MIPS] IP27: Switch to dynamic interrupt routing avoding panic on error.

pcibios_map_irq is no way of returning an error but on IP27 an interrupt
is possibly not routable when running out of resources.  So do the
interrupt routing at pcibios_enable_device time.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 31 insertions, 9 deletions

diff --git a/arch/mips/pci/pci-ip27.c b/arch/mips/pci/pci-ip27.c
index bd78368c82bf..f97ab1461012 100644
--- a/arch/mips/pci/pci-ip27.c
+++ b/arch/mips/pci/pci-ip27.c
@@ -143,25 +143,47 @@ int __cpuinit bridge_probe(nasid_t nasid, int widget_id, int masterwid)
  */
 int __devinit pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 {
+        return 0;
+}
+
+/* Most MIPS systems have straight-forward swizzling needs.  */
+static inline u8 bridge_swizzle(u8 pin, u8 slot)
+{
+        return (((pin - 1) + slot) % 4) + 1;
+}
+
+static inline struct pci_dev *bridge_root_dev(struct pci_dev *dev)
+{
+        while (dev->bus->parent) {
+                /* Move up the chain of bridges. */
+                dev = dev->bus->self;
+        }
+
+        return dev;
+}
+
+/* Do platform specific device initialization at pci_enable_device() time */
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
         struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
-        int irq = bc->pci_int[slot];
+        struct pci_dev *rdev = bridge_root_dev(dev);
+        int slot = PCI_SLOT(rdev->devfn);
+        int irq;
 
+        irq = bc->pci_int[slot];
         if (irq == -1) {
-                irq = bc->pci_int[slot] = request_bridge_irq(bc);
+                irq = request_bridge_irq(bc);
                 if (irq < 0)
-                        panic("Can't allocate interrupt for PCI device %s\n",
-                              pci_name(dev));
+                        return irq;
+
+                bc->pci_int[slot] = irq;
         }
 
         irq_to_bridge[irq] = bc;
         irq_to_slot[irq] = slot;
 
-        return irq;
-}
+        dev->irq = irq;
 
-/* Do platform specific device initialization at pci_enable_device() time */
-int pcibios_plat_dev_init(struct pci_dev *dev)
-{
         return 0;
 }