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>

1 files changed, 14 insertions, 10 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 2a943090a3b7..7feacf521e14 100644
--- 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;
                 }