diff --git a/arch/mips/pci/pci-ip27.c b/arch/mips/pci/pci-ip27.c
new file mode 100644
index 0000000..068e0e5
--- /dev/null
+++ b/arch/mips/pci/pci-ip27.c
@@ -0,0 +1,489 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003 Christoph Hellwig (hch@lst.de)
+ * Copyright (C) 1999, 2000, 04 Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <asm/sn/arch.h>
+#include <asm/pci/bridge.h>
+#include <asm/paccess.h>
+#include <asm/sn/intr.h>
+#include <asm/sn/sn0/hub.h>
+
+extern unsigned int allocate_irqno(void);
+
+/*
+ * Max #PCI busses we can handle; ie, max #PCI bridges.
+ */
+#define MAX_PCI_BUSSES		40
+
+/*
+ * Max #PCI devices (like scsi controllers) we handle on a bus.
+ */
+#define MAX_DEVICES_PER_PCIBUS	8
+
+/*
+ * XXX: No kmalloc available when we do our crosstalk scan,
+ * 	we should try to move it later in the boot process.
+ */
+static struct bridge_controller bridges[MAX_PCI_BUSSES];
+
+/*
+ * Translate from irq to software PCI bus number and PCI slot.
+ */
+struct bridge_controller *irq_to_bridge[MAX_PCI_BUSSES * MAX_DEVICES_PER_PCIBUS];
+int irq_to_slot[MAX_PCI_BUSSES * MAX_DEVICES_PER_PCIBUS];
+
+/*
+ * The Bridge ASIC supports both type 0 and type 1 access.  Type 1 is
+ * not really documented, so right now I can't write code which uses it.
+ * Therefore we use type 0 accesses for now even though they won't work
+ * correcly for PCI-to-PCI bridges.
+ *
+ * The function is complicated by the ultimate brokeness of the IOC3 chip
+ * which is used in SGI systems.  The IOC3 can only handle 32-bit PCI
+ * accesses and does only decode parts of it's address space.
+ */
+
+static int pci_conf0_read_config(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 * value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	bridge_t *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	volatile void *addr;
+	u32 cf, shift, mask;
+	int res;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto oh_my_gawd;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+	if (size == 1)
+		res = get_dbe(*value, (u8 *) addr);
+	else if (size == 2)
+		res = get_dbe(*value, (u16 *) addr);
+	else
+		res = get_dbe(*value, (u32 *) addr);
+
+	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+oh_my_gawd:
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at the wrong register.
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+		*value = 0;
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't try to access
+	 * anything but 32-bit words ...
+	 */
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	*value = (cf >> shift) & mask;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_read_config(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 * value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	bridge_t *bridge = bc->base;
+	int busno = bus->number;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	volatile void *addr;
+	u32 cf, shift, mask;
+	int res;
+
+	bridge->b_pci_cfg = (busno << 16) | (slot << 11);
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto oh_my_gawd;
+
+	bridge->b_pci_cfg = (busno << 16) | (slot << 11);
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+	if (size == 1)
+		res = get_dbe(*value, (u8 *) addr);
+	else if (size == 2)
+		res = get_dbe(*value, (u16 *) addr);
+	else
+		res = get_dbe(*value, (u32 *) addr);
+
+	return res ? PCIBIOS_DEVICE_NOT_FOUND : PCIBIOS_SUCCESSFUL;
+
+oh_my_gawd:
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at the wrong register.
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48)) {
+		*value = 0;
+		return PCIBIOS_SUCCESSFUL;
+	}
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't try to access
+	 * anything but 32-bit words ...
+	 */
+	bridge->b_pci_cfg = (busno << 16) | (slot << 11);
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | where];
+
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	*value = (cf >> shift) & mask;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_read_config(struct pci_bus *bus, unsigned int devfn,
+			   int where, int size, u32 * value)
+{
+	if (bus->number > 0)
+		return pci_conf1_read_config(bus, devfn, where, size, value);
+
+	return pci_conf0_read_config(bus, devfn, where, size, value);
+}
+
+static int pci_conf0_write_config(struct pci_bus *bus, unsigned int devfn,
+				  int where, int size, u32 value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	bridge_t *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	volatile void *addr;
+	u32 cf, shift, mask, smask;
+	int res;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto oh_my_gawd;
+
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].c[where ^ (4 - size)];
+
+	if (size == 1) {
+		res = put_dbe(value, (u8 *) addr);
+	} else if (size == 2) {
+		res = put_dbe(value, (u16 *) addr);
+	} else {
+		res = put_dbe(value, (u32 *) addr);
+	}
+
+	if (res)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+
+oh_my_gawd:
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to touch the wrong register.
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+		return PCIBIOS_SUCCESSFUL;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't try to access
+	 * anything but 32-bit words ...
+	 */
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	smask = mask << shift;
+
+	cf = (cf & ~smask) | ((value & mask) << shift);
+	if (put_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_conf1_write_config(struct pci_bus *bus, unsigned int devfn,
+				  int where, int size, u32 value)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(bus);
+	bridge_t *bridge = bc->base;
+	int slot = PCI_SLOT(devfn);
+	int fn = PCI_FUNC(devfn);
+	int busno = bus->number;
+	volatile void *addr;
+	u32 cf, shift, mask, smask;
+	int res;
+
+	bridge->b_pci_cfg = (busno << 16) | (slot << 11);
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | PCI_VENDOR_ID];
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to look at it for real ...
+	 */
+	if (cf == (PCI_VENDOR_ID_SGI | (PCI_DEVICE_ID_SGI_IOC3 << 16)))
+		goto oh_my_gawd;
+
+	addr = &bridge->b_type1_cfg.c[(fn << 8) | (where ^ (4 - size))];
+
+	if (size == 1) {
+		res = put_dbe(value, (u8 *) addr);
+	} else if (size == 2) {
+		res = put_dbe(value, (u16 *) addr);
+	} else {
+		res = put_dbe(value, (u32 *) addr);
+	}
+
+	if (res)
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+
+oh_my_gawd:
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't even give the
+	 * generic PCI code a chance to touch the wrong register.
+	 */
+	if ((where >= 0x14 && where < 0x40) || (where >= 0x48))
+		return PCIBIOS_SUCCESSFUL;
+
+	/*
+	 * IOC3 is fucked fucked beyond believe ...  Don't try to access
+	 * anything but 32-bit words ...
+	 */
+	addr = &bridge->b_type0_cfg_dev[slot].f[fn].l[where >> 2];
+
+	if (get_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	shift = ((where & 3) << 3);
+	mask = (0xffffffffU >> ((4 - size) << 3));
+	smask = mask << shift;
+
+	cf = (cf & ~smask) | ((value & mask) << shift);
+	if (put_dbe(cf, (u32 *) addr))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int pci_write_config(struct pci_bus *bus, unsigned int devfn,
+	int where, int size, u32 value)
+{
+	if (bus->number > 0)
+		return pci_conf1_write_config(bus, devfn, where, size, value);
+
+	return pci_conf0_write_config(bus, devfn, where, size, value);
+}
+
+static struct pci_ops bridge_pci_ops = {
+	.read = pci_read_config,
+	.write = pci_write_config,
+};
+
+int __init bridge_probe(nasid_t nasid, int widget_id, int masterwid)
+{
+	unsigned long offset = NODE_OFFSET(nasid);
+	struct bridge_controller *bc;
+	static int num_bridges = 0;
+	bridge_t *bridge;
+	int slot;
+
+	printk("a bridge\n");
+
+	/* XXX: kludge alert.. */
+	if (!num_bridges)
+		ioport_resource.end = ~0UL;
+
+	bc = &bridges[num_bridges];
+
+	bc->pc.pci_ops		= &bridge_pci_ops;
+	bc->pc.mem_resource	= &bc->mem;
+	bc->pc.io_resource	= &bc->io;
+
+	bc->pc.index		= num_bridges;
+
+	bc->mem.name		= "Bridge PCI MEM";
+	bc->pc.mem_offset	= offset;
+	bc->mem.start		= 0;
+	bc->mem.end		= ~0UL;
+	bc->mem.flags		= IORESOURCE_MEM;
+
+	bc->io.name		= "Bridge IO MEM";
+	bc->pc.io_offset	= offset;
+	bc->io.start		= 0UL;
+	bc->io.end		= ~0UL;
+	bc->io.flags		= IORESOURCE_IO;
+
+	bc->irq_cpu = smp_processor_id();
+	bc->widget_id = widget_id;
+	bc->nasid = nasid;
+
+	bc->baddr = (u64)masterwid << 60;
+	bc->baddr |= (1UL << 56);	/* Barrier set */
+
+	/*
+	 * point to this bridge
+	 */
+	bridge = (bridge_t *) RAW_NODE_SWIN_BASE(nasid, widget_id);
+
+	/*
+ 	 * Clear all pending interrupts.
+ 	 */
+	bridge->b_int_rst_stat = BRIDGE_IRR_ALL_CLR;
+
+	/*
+ 	 * Until otherwise set up, assume all interrupts are from slot 0
+ 	 */
+	bridge->b_int_device = 0x0;
+
+	/*
+ 	 * swap pio's to pci mem and io space (big windows)
+ 	 */
+	bridge->b_wid_control |= BRIDGE_CTRL_IO_SWAP |
+	                         BRIDGE_CTRL_MEM_SWAP;
+
+	/*
+	 * Hmm...  IRIX sets additional bits in the address which
+	 * are documented as reserved in the bridge docs.
+	 */
+	bridge->b_wid_int_upper = 0x8000 | (masterwid << 16);
+	bridge->b_wid_int_lower = 0x01800090;	/* PI_INT_PEND_MOD off*/
+	bridge->b_dir_map = (masterwid << 20);	/* DMA */
+	bridge->b_int_enable = 0;
+
+	for (slot = 0; slot < 8; slot ++) {
+		bridge->b_device[slot].reg |= BRIDGE_DEV_SWAP_DIR;
+		bc->pci_int[slot] = -1;
+	}
+	bridge->b_wid_tflush;     /* wait until Bridge PIO complete */
+
+	bc->base = bridge;
+
+	register_pci_controller(&bc->pc);
+
+	num_bridges++;
+
+	return 0;
+}
+
+/*
+ * All observed requests have pin == 1. We could have a global here, that
+ * gets incremented and returned every time - unfortunately, pci_map_irq
+ * may be called on the same device over and over, and need to return the
+ * same value. On O2000, pin can be 0 or 1, and PCI slots can be [0..7].
+ *
+ * A given PCI device, in general, should be able to intr any of the cpus
+ * on any one of the hubs connected to its xbow.
+ */
+int __devinit pcibios_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	int irq = bc->pci_int[slot];
+
+	if (irq == -1) {
+		irq = bc->pci_int[slot] = request_bridge_irq(bc);
+		if (irq < 0)
+			panic("Can't allocate interrupt for PCI device %s\n",
+			      pci_name(dev));
+	}
+
+	irq_to_bridge[irq] = bc;
+	irq_to_slot[irq] = slot;
+
+	return irq;
+}
+
+/* Do platform specific device initialization at pci_enable_device() time */
+int pcibios_plat_dev_init(struct pci_dev *dev)
+{
+	return 0;
+}
+
+/*
+ * Device might live on a subordinate PCI bus.  XXX Walk up the chain of buses
+ * to find the slot number in sense of the bridge device register.
+ * XXX This also means multiple devices might rely on conflicting bridge
+ * settings.
+ */
+
+static inline void pci_disable_swapping(struct pci_dev *dev)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	bridge_t *bridge = bc->base;
+	int slot = PCI_SLOT(dev->devfn);
+
+	/* Turn off byte swapping */
+	bridge->b_device[slot].reg &= ~BRIDGE_DEV_SWAP_DIR;
+	bridge->b_widget.w_tflush;	/* Flush */
+}
+
+static inline void pci_enable_swapping(struct pci_dev *dev)
+{
+	struct bridge_controller *bc = BRIDGE_CONTROLLER(dev->bus);
+	bridge_t *bridge = bc->base;
+	int slot = PCI_SLOT(dev->devfn);
+
+	/* Turn on byte swapping */
+	bridge->b_device[slot].reg |= BRIDGE_DEV_SWAP_DIR;
+	bridge->b_widget.w_tflush;	/* Flush */
+}
+
+static void __init pci_fixup_ioc3(struct pci_dev *d)
+{
+	pci_disable_swapping(d);
+}
+
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC3,
+	pci_fixup_ioc3);