diff -u -r build-sgi/xc/programs/Xserver/hw/xfree86/os-support/bus/linuxPci.c build4/xc/programs/Xserver/hw/xfree86/os-support/bus/linuxPci.c
--- build-sgi/xc/programs/Xserver/hw/xfree86/os-support/bus/linuxPci.c	2005-04-15 09:23:03.207875963 -0600
+++ build4/xc/programs/Xserver/hw/xfree86/os-support/bus/linuxPci.c	2005-04-15 09:30:50.700057736 -0600
@@ -422,7 +422,7 @@
 	result = mmap(NULL, Size + Offset, prot, mmapflags, fd, realBase);
 
 	if (!result || ((pointer)result == MAP_FAILED))
-	    FatalError("linuxMapPci() mmap failure:  %s\n", strerror(errno));
+	    return NULL;
 
 	xf86MakeNewMapping(ScreenNum, Flags, realBase, Size + Offset, result);
 
@@ -439,51 +439,74 @@
 static pointer DomainMmappedIO[MAX_DOMAINS];
 static pointer DomainMmappedMem[MAX_DOMAINS];
 
+static int
+linuxOpenLegacy(PCITAG Tag, char *name)
+{
+#define PREFIX "/sys/class/pci_bus/%04x:%02x/%s"
+    char *path;
+    int domain, bus;
+    pciBusInfo_t *pBusInfo;
+    pciConfigPtr bridge;
+    int fd;
+
+    path = xalloc(strlen(PREFIX) + strlen(name));
+    if (!path)
+	return -1;
+
+    for (;;) {
+	domain = xf86GetPciDomain(Tag);
+	bus = PCI_BUS_NO_DOMAIN(PCI_BUS_FROM_TAG(Tag));
+
+	/* Domain 0 is reserved -- see xf86GetPciDomain() */
+	if ((domain <= 0) || (domain >= MAX_DOMAINS))
+	    FatalError("linuxOpenLegacy():  domain out of range\n");
+
+	sprintf(path, PREFIX, domain - 1, bus, name);
+	fd = open(path, O_RDWR);
+	if (fd >= 0) {
+	    xfree(path);
+	    return fd;
+	}
+
+	pBusInfo = pciBusInfo[bus];
+	if (!pBusInfo || (bridge == pBusInfo->bridge) ||
+		!(bridge = pBusInfo->bridge)) {
+	    xfree(path);
+	    return -1;
+	}
+
+	Tag = bridge->tag;
+    }
+
+    xfree(path);
+    return fd;
+}
+
 pointer
 xf86MapDomainMemory(int ScreenNum, int Flags, PCITAG Tag,
 		    ADDRESS Base, unsigned long Size)
 {
-    char path[38]; /* /sys/class/pci_bus/DDDD:BB/legacy_mem */
     int domain = xf86GetPciDomain(Tag);
-    int bus = PCI_BUS_FROM_TAG(Tag);
     int fd;
-    struct stat st;
 
-    /* 
-     * If we are running a new enough linux kernel (2.6.11+)
-     * then we can open the legacy space through the /sys interface
-     * this allows us to open the device and use a read/write/seek
-     * interface to read/write bytes into legacy space.
-     * 
-     * We will use this interface for accesses to IO mapped regions
-     * on the graphics card and all vga accesses
-     */
-    
-    /* Hack, need to deal with domains correctly */
-    sprintf(path, "/sys/class/pci_bus/%04x:%02x/legacy_mem", 0, bus);
-    
     /*
     * if the /sys/...../legacy_mem structure is not supported in the 
     * running linux kernel, switch to the previous method
     */
     if ((Base > 1024*1024 /* 1MB since that is legacy space*/) ||
-	(stat(path, &st) < 0))
+	(fd = linuxOpenLegacy(Tag, "legacy_mem")) < 0)
         return linuxMapPci(ScreenNum, Flags, Tag, Base, Size, PCIIOC_MMAP_IS_MEM);
     
-    if ((domain <= 0) || (domain >= MAX_DOMAINS))
-	FatalError("xf86MapDomainMem():  domain out of range\n");
-    
     /* Permanently map all of memory space */
     if (!DomainMmappedMem[domain]) {
-        fd = open(path, O_RDWR);
 	DomainMmappedMem[domain] = mmap(0, 1024*1024 /* 1MB, all of legacy space */,
 					PROT_READ|PROT_WRITE,
 					MAP_SHARED, fd, 0);
-        close(fd);
 	if (!DomainMmappedMem[domain])
 	    FatalError("xf86MapDomainMem():  mmap() failure\n");
     }
     
+    close(fd);
     return (pointer)((char *)DomainMmappedMem[domain] + Base);
 }
 
@@ -492,23 +515,24 @@
 xf86MapDomainIO(int ScreenNum, int Flags, PCITAG Tag,
 		IOADDRESS Base, unsigned long Size)
 {
-    char path[37]; /* /sys/class/pci_bus/DDDD:BB/legacy_io */
     int domain = xf86GetPciDomain(Tag);
-    int bus = PCI_BUS_FROM_TAG(Tag);
     int fd;
 
     if ((domain <= 0) || (domain >= MAX_DOMAINS))
 	FatalError("xf86MapDomainIO():  domain out of range\n");
 
-    /* Hack, need to deal with domains properly */
-    sprintf(path, "/sys/class/pci_bus/%04x:%02x/legacy_io", 0, bus);
-
     /* Permanently map all of I/O space */
     if (!DomainMmappedIO[domain]) {
-        fd = open(path, O_RDWR);
-	if (fd == -1)
-	    FatalError("xf86MapDomainIO():  open() failure\n");
-	DomainMmappedIO[domain] = fd << 24; /* encode fd in address */
+        if ((fd = linuxOpenLegacy(Tag, "legacy_io")) >= 0) {
+	    DomainMmappedIO[domain] = fd << 24; /* encode fd in address */
+	} else {
+	    DomainMmappedIO[domain] = linuxMapPci(ScreenNum, Flags, Tag,
+						  0, linuxGetIOSize(Tag),
+						  PCIIOC_MMAP_IS_IO);
+	    /* ia64 can't mmap legacy IO port space */
+	    if (!DomainMmappedIO[domain])
+		return Base;
+	}
     }
 
     return (IOADDRESS)DomainMmappedIO[domain] + Base;