[PATCH v3 6/7] PCI: break out primary/secondary/subordinate for readability

Bjorn Helgaas
2010-02-12T17:00:26Z

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>
---

drivers/pci/probe.c | 24 ++++++++++++++----------
1 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index dacdeae..04e7e97 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -671,16 +671,20 @@ 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;
}
@@ -691,15 +695,15 @@ 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,
@@ -708,13 +712,13 @@ 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;
}