[PATCH] enable PCI bridges in MIPS ip32

[Giuseppe Sacco <giuseppe@eppesuigoccas.homedns.org>]

Use bus numbering when addressing device with MACE chipset
in order to support PCI bridges.
Changes in chkslot() and mkaddr() #defines.

Signed-off-by: Giuseppe Sacco <eppesuig@debian.org>
---

Hi Ralf,
I managed to create a patch against current 2.6.23-rc9 git tree
for supporting PCI bridges on SGI ip32 machines.
This is my first kernel patch, so I am usure about the correct way
to send a patch. Please let me know if anything is wrong.

Bye,
Giuseppe

diff --git a/arch/mips/pci/ops-mace.c b/arch/mips/pci/ops-mace.c
index 8008e31..18a7159 100644
--- a/arch/mips/pci/ops-mace.c
+++ b/arch/mips/pci/ops-mace.c
@@ -31,20 +31,21 @@
 
 #define chkslot(_bus,_devfn)                                   \
 do {                                                           \
-       if ((_bus)->number > 0 || PCI_SLOT (_devfn) < 1 \
-           || PCI_SLOT (_devfn) > 3)                           \
+       if ((_bus)->number > 1 ||                               \
+               ((_bus)->number == 0 && (PCI_SLOT (_devfn) < 1  \
+               || PCI_SLOT (_devfn) > 3)))                     \
                return PCIBIOS_DEVICE_NOT_FOUND;                \
 } while (0)
 
-#define mkaddr(_devfn, _reg) \
-((((_devfn) & 0xffUL) << 8) | ((_reg) & 0xfcUL))
+#define mkaddr(_bus, _devfn, _reg) \
+((((_bus)->number & 0xffUL) << 16) | (((_devfn) & 0xffUL) << 8) | ((_reg) & 
0xfcUL))
 
 static int
 mace_pci_read_config(struct pci_bus *bus, unsigned int devfn,
                     int reg, int size, u32 *val)
 {
        chkslot(bus, devfn);
-       mace->pci.config_addr = mkaddr(devfn, reg);
+       mace->pci.config_addr = mkaddr(bus, devfn, reg);
        switch (size) {
        case 1:
                *val = mace->pci.config_data.b[(reg & 3) ^ 3];
@@ -67,7 +68,7 @@ mace_pci_write_config(struct pci_bus *bus, unsigned int devfn,
                      int reg, int size, u32 val)
 {
        chkslot(bus, devfn);
-       mace->pci.config_addr = mkaddr(devfn, reg);
+       mace->pci.config_addr = mkaddr(bus, devfn, reg);
        switch (size) {
        case 1:
                mace->pci.config_data.b[(reg & 3) ^ 3] = val;