diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 9c5d2a992999..ef24cf765b2f 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -269,15 +269,23 @@ static void __devinit pci_read_bridge_io(struct pci_bus *child)
 {
 	struct pci_dev *dev = child->self;
 	u8 io_base_lo, io_limit_lo;
-	unsigned long base, limit;
+	unsigned long io_mask, io_granularity, base, limit;
 	struct pci_bus_region region;
-	struct resource *res, res2;
+	struct resource *res;
+
+	io_mask = PCI_IO_RANGE_MASK;
+	io_granularity = 0x1000;
+	if (dev->io_window_1k) {
+		/* Support 1K I/O space granularity */
+		io_mask = PCI_IO_1K_RANGE_MASK;
+		io_granularity = 0x400;
+	}
 
 	res = child->resource[0];
 	pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
 	pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
-	base = (io_base_lo & PCI_IO_RANGE_MASK) << 8;
-	limit = (io_limit_lo & PCI_IO_RANGE_MASK) << 8;
+	base = (io_base_lo & io_mask) << 8;
+	limit = (io_limit_lo & io_mask) << 8;
 
 	if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
 		u16 io_base_hi, io_limit_hi;
@@ -289,14 +297,9 @@ static void __devinit pci_read_bridge_io(struct pci_bus *child)
 
 	if (base <= limit) {
 		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
-		res2.flags = res->flags;
 		region.start = base;
-		region.end = limit + 0xfff;
-		pcibios_bus_to_resource(dev, &res2, &region);
-		if (!res->start)
-			res->start = res2.start;
-		if (!res->end)
-			res->end = res2.end;
+		region.end = limit + io_granularity - 1;
+		pcibios_bus_to_resource(dev, res, &region);
 		dev_printk(KERN_DEBUG, &dev->dev, "  bridge window %pR\n", res);
 	}
 }
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2a7521677541..356846bd7ffb 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1938,53 +1938,16 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_NCR, PCI_DEVICE_ID_NCR_53C810, fixup_rev1
 static void __devinit quirk_p64h2_1k_io(struct pci_dev *dev)
 {
 	u16 en1k;
-	u8 io_base_lo, io_limit_lo;
-	unsigned long base, limit;
-	struct resource *res = dev->resource + PCI_BRIDGE_RESOURCES;
 
 	pci_read_config_word(dev, 0x40, &en1k);
 
 	if (en1k & 0x200) {
 		dev_info(&dev->dev, "Enable I/O Space to 1KB granularity\n");
-
-		pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
-		pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
-		base = (io_base_lo & (PCI_IO_RANGE_MASK | 0x0c)) << 8;
-		limit = (io_limit_lo & (PCI_IO_RANGE_MASK | 0x0c)) << 8;
-
-		if (base <= limit) {
-			res->start = base;
-			res->end = limit + 0x3ff;
-		}
+		dev->io_window_1k = 1;
 	}
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,	0x1460,		quirk_p64h2_1k_io);
 
-/* Fix the IOBL_ADR for 1k I/O space granularity on the Intel P64H2
- * The IOBL_ADR gets re-written to 4k boundaries in pci_setup_bridge()
- * in drivers/pci/setup-bus.c
- */
-static void __devinit quirk_p64h2_1k_io_fix_iobl(struct pci_dev *dev)
-{
-	u16 en1k, iobl_adr, iobl_adr_1k;
-	struct resource *res = dev->resource + PCI_BRIDGE_RESOURCES;
-
-	pci_read_config_word(dev, 0x40, &en1k);
-
-	if (en1k & 0x200) {
-		pci_read_config_word(dev, PCI_IO_BASE, &iobl_adr);
-
-		iobl_adr_1k = iobl_adr | (res->start >> 8) | (res->end & 0xfc00);
-
-		if (iobl_adr != iobl_adr_1k) {
-			dev_info(&dev->dev, "Fixing P64H2 IOBL_ADR from 0x%x to 0x%x for 1KB granularity\n",
-				iobl_adr,iobl_adr_1k);
-			pci_write_config_word(dev, PCI_IO_BASE, iobl_adr_1k);
-		}
-	}
-}
-DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL,	0x1460,		quirk_p64h2_1k_io_fix_iobl);
-
 /* Under some circumstances, AER is not linked with extended capabilities.
  * Force it to be linked by setting the corresponding control bit in the
  * config space.
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 8fa2d4be88de..dad5425f1f09 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -469,16 +469,23 @@ static void pci_setup_bridge_io(struct pci_bus *bus)
 	struct pci_dev *bridge = bus->self;
 	struct resource *res;
 	struct pci_bus_region region;
+	unsigned long io_mask;
+	u8 io_base_lo, io_limit_lo;
 	u32 l, io_upper16;
 
+	io_mask = PCI_IO_RANGE_MASK;
+	if (bridge->io_window_1k)
+		io_mask = PCI_IO_1K_RANGE_MASK;
+
 	/* Set up the top and bottom of the PCI I/O segment for this bus. */
 	res = bus->resource[0];
 	pcibios_resource_to_bus(bridge, &region, res);
 	if (res->flags & IORESOURCE_IO) {
 		pci_read_config_dword(bridge, PCI_IO_BASE, &l);
 		l &= 0xffff0000;
-		l |= (region.start >> 8) & 0x00f0;
-		l |= region.end & 0xf000;
+		io_base_lo = (region.start >> 8) & io_mask;
+		io_limit_lo = (region.end >> 8) & io_mask;
+		l |= ((u32) io_limit_lo << 8) | io_base_lo;
 		/* Set up upper 16 bits of I/O base/limit. */
 		io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
 		dev_info(&bridge->dev, "  bridge window %pR\n", res);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d8c379dba6ad..89b46fd245c6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -324,6 +324,7 @@ struct pci_dev {
 	unsigned int    is_hotplug_bridge:1;
 	unsigned int    __aer_firmware_first_valid:1;
 	unsigned int	__aer_firmware_first:1;
+	unsigned int	io_window_1k:1;	/* Intel P2P bridge 1K I/O windows */
 	pci_dev_flags_t dev_flags;
 	atomic_t	enable_cnt;	/* pci_enable_device has been called */
 
diff --git a/include/linux/pci_regs.h b/include/linux/pci_regs.h
index 4b608f543412..88c9ea56e252 100644
--- a/include/linux/pci_regs.h
+++ b/include/linux/pci_regs.h
@@ -125,7 +125,8 @@
 #define  PCI_IO_RANGE_TYPE_MASK	0x0fUL	/* I/O bridging type */
 #define  PCI_IO_RANGE_TYPE_16	0x00
 #define  PCI_IO_RANGE_TYPE_32	0x01
-#define  PCI_IO_RANGE_MASK	(~0x0fUL)
+#define  PCI_IO_RANGE_MASK	(~0x0fUL) /* Standard 4K I/O windows */
+#define  PCI_IO_1K_RANGE_MASK	(~0x03UL) /* Intel 1K I/O windows */
 #define PCI_SEC_STATUS		0x1e	/* Secondary status register, only bit 14 used */
 #define PCI_MEMORY_BASE		0x20	/* Memory range behind */
 #define PCI_MEMORY_LIMIT	0x22