[PATCH] alpha: pci domains update

- fix thinko in pci_name_bus (pointed out by DaveM);
- prevent 8-bit bus number overflow inside the hose;
- remove first_busno/last_busno fields from struct pci_controller,
  as it's a duplicate of the info in associated struct pci_bus.

Ivan.

arch/alpha/kernel/core_marvel.c

@@ -524,7 +524,7 @@ mk_conf_addr(struct pci_bus *pbus, unsigned int devfn, int where)
 	if (!io7_port->enabled)
 		return addr;
 
-	if (hose->first_busno == bus) {
+	if (hose->bus == pbus) {
 		/* Don't support idsel > 20 on primary bus.  */
 		if (devfn >= PCI_DEVFN(21, 0))
 			return addr;

arch/alpha/kernel/core_mcpcia.c

@@ -185,7 +185,7 @@ mk_conf_addr(struct pci_bus *pbus, unsigned int devfn, int where,
 	/* Type 1 configuration cycle for *ALL* busses.  */
 	*type1 = 1;
 
-	if (bus == hose->first_busno)
+	if (hose->bus == pbus)
 		bus = 0;
 	addr = (bus << 16) | (devfn << 8) | (where);
 	addr <<= 5; /* swizzle for SPARSE */

arch/alpha/kernel/core_tsunami.c

@@ -101,7 +101,7 @@ mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
 		 "pci_addr=0x%p, type1=0x%p)\n",
 		 bus, device_fn, where, pci_addr, type1));
 
-	if (hose->first_busno == bus)
+	if (hose->bus == pbus)
 		bus = 0;
 	*type1 = (bus != 0);
 

arch/alpha/kernel/core_wildfire.c

@@ -367,7 +367,7 @@ mk_conf_addr(struct pci_bus *pbus, unsigned int device_fn, int where,
 		 "pci_addr=0x%p, type1=0x%p)\n",
 		 bus, device_fn, where, pci_addr, type1));
 
-	if (hose->first_busno == bus)
+	if (hose->bus == pbus)
 		bus = 0;
 	*type1 = (bus != 0);
 

arch/alpha/kernel/pci.c

@@ -280,7 +280,7 @@ common_swizzle(struct pci_dev *dev, u8 *pinp)
 {
 	struct pci_controller *hose = dev->sysdata;
 
-	if (dev->bus->number != hose->first_busno) {
+	if (dev->bus != hose->bus) {
 		u8 pin = *pinp;
 		do {
 			pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
@@ -398,15 +398,20 @@ common_init_pci(void)
 	struct pci_controller *hose;
 	struct pci_bus *bus;
 	int next_busno;
+	int need_domain_info = 0;
 
 	/* Scan all of the recorded PCI controllers.  */
 	for (next_busno = 0, hose = hose_head; hose; hose = hose->next) {
-		hose->first_busno = next_busno;
-		hose->last_busno = 0xff;
 		bus = pci_scan_bus(next_busno, alpha_mv.pci_ops, hose);
 		hose->bus = bus;
-		next_busno = hose->last_busno = bus->subordinate;
-		next_busno += 1;
+		hose->need_domain_info = need_domain_info;
+		next_busno = bus->subordinate + 1;
+		/* Don't allow 8-bit bus number overflow inside the hose -
+		   reserve some space for bridges. */ 
+		if (next_busno > 224) {
+			next_busno = 0;
+			need_domain_info = 1;
+		}
 	}
 
 	if (pci_probe_only)

arch/alpha/kernel/sys_dp264.c

@@ -463,7 +463,7 @@ monet_swizzle(struct pci_dev *dev, u8 *pinp)
 	struct pci_controller *hose = dev->sysdata;
 	int slot, pin = *pinp;
 
-	if (hose->first_busno == dev->bus->number) {
+	if (hose->bus == dev->bus) {
 		slot = PCI_SLOT(dev->devfn);
 	}
 	/* Check for the built-in bridge on hose 1. */

arch/alpha/kernel/sys_nautilus.c

@@ -200,7 +200,6 @@ nautilus_init_pci(void)
 	/* Scan our single hose.  */
 	bus = pci_scan_bus(0, alpha_mv.pci_ops, hose);
 	hose->bus = bus;
-	hose->last_busno = bus->subordinate;
 
 	irongate = pci_find_slot(0, 0);
 	bus->self = irongate;

include/asm-alpha/pci.h

@@ -37,8 +37,9 @@ struct pci_controller {
 	unsigned long config_space_base;
 
 	unsigned int index;
-	unsigned int first_busno;
-	unsigned int last_busno;
+	/* For compatibility with current (as of July 2003) pciutils
+	   and XFree86. Eventually will be removed. */
+	unsigned int need_domain_info;
 
 	struct pci_iommu_arena *sg_pci;
 	struct pci_iommu_arena *sg_isa;
@@ -194,15 +195,14 @@ pcibios_resource_to_bus(struct pci_dev *dev, struct pci_bus_region *region,
 
 #define pci_domain_nr(bus) ((struct pci_controller *)(bus)->sysdata)->index
 
-/* Bus number == domain number until we get above 256 busses */
 static inline int pci_name_bus(char *name, struct pci_bus *bus)
 {
-	int domain = pci_domain_nr(bus);
+	struct pci_controller *hose = bus->sysdata;
 
-	if (domain < 256) {
-		sprintf(name, "%02x", domain);
+	if (likely(hose->need_domain_info == 0)) {
+		sprintf(name, "%02x", bus->number);
 	} else {
-		sprintf(name, "%04x:%02x", domain, bus->number);
+		sprintf(name, "%04x:%02x", hose->index, bus->number);
 	}
 	return 0;
 }