[PARISC] Fix PCI bus numbering in the presence of Cardbus bridges

Firmware ignores Cardbus bridges, so when Linux assigns bus numbers,
it must override firmware's notion of what the busses are numbered.
This is not sufficient to support the Cardbus bridge as there is also
no interrupt routing table entry for them.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 19 insertions, 13 deletions

diff --git a/drivers/parisc/lba_pci.c b/drivers/parisc/lba_pci.c
index ad4a1a12a1ae..eae0812f01a5 100644
--- a/drivers/parisc/lba_pci.c
+++ b/drivers/parisc/lba_pci.c
@@ -1406,13 +1406,20 @@ lba_hw_init(struct lba_device *d)
         return 0;
 }
 
-
+/*
+ * Unfortunately, when firmware numbers busses, it doesn't take into account
+ * Cardbus bridges.  So we have to renumber the busses to suit ourselves.
+ * Elroy/Mercury don't actually know what bus number they're attached to;
+ * we use bus 0 to indicate the directly attached bus and any other bus
+ * number will be taken care of by the PCI-PCI bridge.
+ */
+static unsigned int lba_next_bus = 0;
 
 /*
-** Determine if lba should claim this chip (return 0) or not (return 1).
-** If so, initialize the chip and tell other partners in crime they
-** have work to do.
-*/
+ * Determine if lba should claim this chip (return 0) or not (return 1).
+ * If so, initialize the chip and tell other partners in crime they
+ * have work to do.
+ */
 static int __init
 lba_driver_probe(struct parisc_device *dev)
 {
@@ -1478,9 +1485,7 @@ lba_driver_probe(struct parisc_device *dev)
                 return -ENODEV;
         }
 
-        /*
-        ** Tell I/O SAPIC driver we have a IRQ handler/region.
-        */
+        /* Tell I/O SAPIC driver we have a IRQ handler/region. */
         tmp_obj = iosapic_register(dev->hpa.start + LBA_IOSAPIC_BASE);
 
         /* NOTE: PCI devices (e.g. 103c:1005 graphics card) which don't
@@ -1529,16 +1534,17 @@ lba_driver_probe(struct parisc_device *dev)
                 lba_legacy_resources(dev, lba_dev);
         }
 
-        /* 
-        ** Tell PCI support another PCI bus was found.
-        ** Walks PCI bus for us too.
-        */
+        if (lba_dev->hba.bus_num.start < lba_next_bus)
+                lba_dev->hba.bus_num.start = lba_next_bus;
+
         dev->dev.platform_data = lba_dev;
         lba_bus = lba_dev->hba.hba_bus =
                 pci_scan_bus_parented(&dev->dev, lba_dev->hba.bus_num.start,
                                 cfg_ops, NULL);
-        if (lba_bus)
+        if (lba_bus) {
+                lba_next_bus = lba_bus->subordinate + 1;
                 pci_bus_add_devices(lba_bus);
+        }
 
         /* This is in lieu of calling pci_assign_unassigned_resources() */
         if (is_pdc_pat()) {