diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 30a5111ae5fd..527e69b12002 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -635,6 +635,22 @@ static void quirk_no_aersid(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
 			      PCI_CLASS_BRIDGE_PCI, 8, quirk_no_aersid);
 
+static void quirk_intel_th_dnv(struct pci_dev *dev)
+{
+	struct resource *r = &dev->resource[4];
+
+	/*
+	 * Denverton reports 2k of RTIT_BAR (intel_th resource 4), which
+	 * appears to be 4 MB in reality.
+	 */
+	if (r->end == r->start + 0x7ff) {
+		r->start = 0;
+		r->end   = 0x3fffff;
+		r->flags |= IORESOURCE_UNSET;
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, 0x19e1, quirk_intel_th_dnv);
+
 #ifdef CONFIG_PHYS_ADDR_T_64BIT
 
 #define AMD_141b_MMIO_BASE(x)	(0x80 + (x) * 0x8)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 13d65991c77b..9ba18515ccc5 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6049,8 +6049,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev)
 	 * to enable the kernel to reassign new resource
 	 * window later on.
 	 */
-	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
-	    (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
+	if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 		for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
 			r = &dev->resource[i];
 			if (!(r->flags & IORESOURCE_MEM))
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 1078195f244a..2ec0df04e0dc 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -121,13 +121,13 @@ static u64 pci_size(u64 base, u64 maxbase, u64 mask)
 	 * Get the lowest of them to find the decode size, and from that
 	 * the extent.
 	 */
-	size = (size & ~(size-1)) - 1;
+	size = size & ~(size-1);
 
 	/*
 	 * base == maxbase can be valid only if the BAR has already been
 	 * programmed with all 1s.
 	 */
-	if (base == maxbase && ((base | size) & mask) != mask)
+	if (base == maxbase && ((base | (size - 1)) & mask) != mask)
 		return 0;
 
 	return size;
@@ -278,7 +278,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 			/* Above 32-bit boundary; try to reallocate */
 			res->flags |= IORESOURCE_UNSET;
 			res->start = 0;
-			res->end = sz64;
+			res->end = sz64 - 1;
 			pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n",
 				 pos, (unsigned long long)l64);
 			goto out;
@@ -286,7 +286,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 	}
 
 	region.start = l64;
-	region.end = l64 + sz64;
+	region.end = l64 + sz64 - 1;
 
 	pcibios_bus_to_resource(dev->bus, res, &region);
 	pcibios_resource_to_bus(dev->bus, &inverted_region, res);
@@ -348,6 +348,57 @@ static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
 	}
 }
 
+static void pci_read_bridge_windows(struct pci_dev *bridge)
+{
+	u16 io;
+	u32 pmem, tmp;
+
+	pci_read_config_word(bridge, PCI_IO_BASE, &io);
+	if (!io) {
+		pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
+		pci_read_config_word(bridge, PCI_IO_BASE, &io);
+		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
+	}
+	if (io)
+		bridge->io_window = 1;
+
+	/*
+	 * DECchip 21050 pass 2 errata: the bridge may miss an address
+	 * disconnect boundary by one PCI data phase.  Workaround: do not
+	 * use prefetching on this device.
+	 */
+	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
+		return;
+
+	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+	if (!pmem) {
+		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
+					       0xffe0fff0);
+		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
+	}
+	if (!pmem)
+		return;
+
+	bridge->pref_window = 1;
+
+	if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
+
+		/*
+		 * Bridge claims to have a 64-bit prefetchable memory
+		 * window; verify that the upper bits are actually
+		 * writable.
+		 */
+		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem);
+		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+				       0xffffffff);
+		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
+		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem);
+		if (tmp)
+			bridge->pref_64_window = 1;
+	}
+}
+
 static void pci_read_bridge_io(struct pci_bus *child)
 {
 	struct pci_dev *dev = child->self;
@@ -1728,9 +1779,6 @@ int pci_setup_device(struct pci_dev *dev)
 		break;
 
 	case PCI_HEADER_TYPE_BRIDGE:		    /* bridge header */
-		if (class != PCI_CLASS_BRIDGE_PCI)
-			goto bad;
-
 		/*
 		 * The PCI-to-PCI bridge spec requires that subtractive
 		 * decoding (i.e. transparent) bridge must have programming
@@ -1739,6 +1787,7 @@ int pci_setup_device(struct pci_dev *dev)
 		pci_read_irq(dev);
 		dev->transparent = ((dev->class & 0xff) == 1);
 		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
+		pci_read_bridge_windows(dev);
 		set_pcie_hotplug_bridge(dev);
 		pos = pci_find_capability(dev, PCI_CAP_ID_SSVID);
 		if (pos) {
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index ed960436df5e..ec44a0f3a7ac 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -735,58 +735,21 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
    base/limit registers must be read-only and read as 0. */
 static void pci_bridge_check_ranges(struct pci_bus *bus)
 {
-	u16 io;
-	u32 pmem;
 	struct pci_dev *bridge = bus->self;
-	struct resource *b_res;
+	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 
-	b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 	b_res[1].flags |= IORESOURCE_MEM;
 
-	pci_read_config_word(bridge, PCI_IO_BASE, &io);
-	if (!io) {
-		pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
-		pci_read_config_word(bridge, PCI_IO_BASE, &io);
-		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
-	}
-	if (io)
+	if (bridge->io_window)
 		b_res[0].flags |= IORESOURCE_IO;
 
-	/*  DECchip 21050 pass 2 errata: the bridge may miss an address
-	    disconnect boundary by one PCI data phase.
-	    Workaround: do not use prefetching on this device. */
-	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
-		return;
-
-	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
-	if (!pmem) {
-		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
-					       0xffe0fff0);
-		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
-		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
-	}
-	if (pmem) {
+	if (bridge->pref_window) {
 		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
-		if ((pmem & PCI_PREF_RANGE_TYPE_MASK) ==
-		    PCI_PREF_RANGE_TYPE_64) {
+		if (bridge->pref_64_window) {
 			b_res[2].flags |= IORESOURCE_MEM_64;
 			b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
 		}
 	}
-
-	/* double check if bridge does support 64 bit pref */
-	if (b_res[2].flags & IORESOURCE_MEM_64) {
-		u32 mem_base_hi, tmp;
-		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
-					 &mem_base_hi);
-		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
-					       0xffffffff);
-		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
-		if (!tmp)
-			b_res[2].flags &= ~IORESOURCE_MEM_64;
-		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
-				       mem_base_hi);
-	}
 }
 
 /* Helper function for sizing routines: find first available
@@ -1223,12 +1186,12 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		if (!b)
 			continue;
 
-		switch (dev->class >> 8) {
-		case PCI_CLASS_BRIDGE_CARDBUS:
+		switch (dev->hdr_type) {
+		case PCI_HEADER_TYPE_CARDBUS:
 			pci_bus_size_cardbus(b, realloc_head);
 			break;
 
-		case PCI_CLASS_BRIDGE_PCI:
+		case PCI_HEADER_TYPE_BRIDGE:
 		default:
 			__pci_bus_size_bridges(b, realloc_head);
 			break;
@@ -1239,12 +1202,12 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 	if (pci_is_root_bus(bus))
 		return;
 
-	switch (bus->self->class >> 8) {
-	case PCI_CLASS_BRIDGE_CARDBUS:
+	switch (bus->self->hdr_type) {
+	case PCI_HEADER_TYPE_CARDBUS:
 		/* don't size cardbuses yet. */
 		break;
 
-	case PCI_CLASS_BRIDGE_PCI:
+	case PCI_HEADER_TYPE_BRIDGE:
 		pci_bridge_check_ranges(bus);
 		if (bus->self->is_hotplug_bridge) {
 			additional_io_size  = pci_hotplug_io_size;
@@ -1393,13 +1356,13 @@ void __pci_bus_assign_resources(const struct pci_bus *bus,
 
 		__pci_bus_assign_resources(b, realloc_head, fail_head);
 
-		switch (dev->class >> 8) {
-		case PCI_CLASS_BRIDGE_PCI:
+		switch (dev->hdr_type) {
+		case PCI_HEADER_TYPE_BRIDGE:
 			if (!pci_is_enabled(dev))
 				pci_setup_bridge(b);
 			break;
 
-		case PCI_CLASS_BRIDGE_CARDBUS:
+		case PCI_HEADER_TYPE_CARDBUS:
 			pci_setup_cardbus(b);
 			break;
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 65f1d8c2f082..40b327b814aa 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -373,6 +373,9 @@ struct pci_dev {
 	bool		match_driver;		/* Skip attaching driver */
 
 	unsigned int	transparent:1;		/* Subtractive decode bridge */
+	unsigned int	io_window:1;		/* Bridge has I/O window */
+	unsigned int	pref_window:1;		/* Bridge has pref mem window */
+	unsigned int	pref_64_window:1;	/* Pref mem window is 64-bit */
 	unsigned int	multifunction:1;	/* Multi-function device */
 
 	unsigned int	is_busmaster:1;		/* Is busmaster */