PCI: break out primary/secondary/subordinate for readability

No functional change; just add names for the primary/secondary/subordinate
bus numbers read from config space rather than repeatedly masking/shifting.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2a94309..7feacf5 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -673,16 +673,20 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
        int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
        u32 buses, i, j = 0;
        u16 bctl;
+       u8 primary, secondary, subordinate;
        int broken = 0;
 
        pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
+       primary = buses & 0xFF;
+       secondary = (buses >> 8) & 0xFF;
+       subordinate = (buses >> 16) & 0xFF;
 
-       dev_dbg(&dev->dev, "scanning behind bridge, config %06x, pass %d\n",
-               buses & 0xffffff, pass);
+       dev_dbg(&dev->dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
+               secondary, subordinate, pass);
 
        /* Check if setup is sensible at all */
        if (!pass &&
-           ((buses & 0xff) != bus->number || ((buses >> 8) & 0xff) <= bus->number)) {
+           (primary != bus->number || secondary <= bus->number)) {
                dev_dbg(&dev->dev, "bus configuration invalid, reconfiguring\n");
                broken = 1;
        }
@@ -693,15 +697,15 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
        pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
                              bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
 
-       if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus && !broken) {
-               unsigned int cmax, busnr;
+       if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
+           !is_cardbus && !broken) {
+               unsigned int cmax;
                /*
                 * Bus already configured by firmware, process it in the first
                 * pass and just note the configuration.
                 */
                if (pass)
                        goto out;
-               busnr = (buses >> 8) & 0xFF;
 
                /*
                 * If we already got to this bus through a different bridge,
@@ -710,13 +714,13 @@ int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max,
                 * However, we continue to descend down the hierarchy and
                 * scan remaining child buses.
                 */
-               child = pci_find_bus(pci_domain_nr(bus), busnr);
+               child = pci_find_bus(pci_domain_nr(bus), secondary);
                if (!child) {
-                       child = pci_add_new_bus(bus, dev, busnr);
+                       child = pci_add_new_bus(bus, dev, secondary);
                        if (!child)
                                goto out;
-                       child->primary = buses & 0xFF;
-                       child->subordinate = (buses >> 16) & 0xFF;
+                       child->primary = primary;
+                       child->subordinate = subordinate;
                        child->bridge_ctl = bctl;
                }