diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 9c69e7e145c5..4fee63cb53ff 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -1366,12 +1366,17 @@ static void __init pcibios_allocate_resources(int pass)
 
 	for_each_pci_dev(dev) {
 		pci_read_config_word(dev, PCI_COMMAND, &command);
-		for (idx = 0; idx < 6; idx++) {
+		for (idx = 0; idx <= PCI_ROM_RESOURCE; idx++) {
 			r = &dev->resource[idx];
 			if (r->parent)		/* Already allocated */
 				continue;
 			if (!r->flags || (r->flags & IORESOURCE_UNSET))
 				continue;	/* Not assigned at all */
+			/* We only allocate ROMs on pass 1 just in case they
+			 * have been screwed up by firmware
+			 */
+			if (idx == PCI_ROM_RESOURCE )
+				disabled = 1;
 			if (r->flags & IORESOURCE_IO)
 				disabled = !(command & PCI_COMMAND_IO);
 			else
@@ -1382,17 +1387,19 @@ static void __init pcibios_allocate_resources(int pass)
 		if (pass)
 			continue;
 		r = &dev->resource[PCI_ROM_RESOURCE];
-		if (r->flags & IORESOURCE_ROM_ENABLE) {
+		if (r->flags) {
 			/* Turn the ROM off, leave the resource region,
 			 * but keep it unregistered.
 			 */
 			u32 reg;
-			pr_debug("PCI: Switching off ROM of %s\n",
-				 pci_name(dev));
-			r->flags &= ~IORESOURCE_ROM_ENABLE;
 			pci_read_config_dword(dev, dev->rom_base_reg, &reg);
-			pci_write_config_dword(dev, dev->rom_base_reg,
-					       reg & ~PCI_ROM_ADDRESS_ENABLE);
+			if (reg & PCI_ROM_ADDRESS_ENABLE) {
+				pr_debug("PCI: Switching off ROM of %s\n",
+					 pci_name(dev));
+				r->flags &= ~IORESOURCE_ROM_ENABLE;
+				pci_write_config_dword(dev, dev->rom_base_reg,
+						       reg & ~PCI_ROM_ADDRESS_ENABLE);
+			}
 		}
 	}
 }
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index be574fc0d92f..96edb6f8babb 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -64,7 +64,7 @@ static u32 get_int_prop(struct device_node *np, const char *name, u32 def)
 	return def;
 }
 
-static unsigned int pci_parse_of_flags(u32 addr0)
+static unsigned int pci_parse_of_flags(u32 addr0, int bridge)
 {
 	unsigned int flags = 0;
 
@@ -75,8 +75,17 @@ static unsigned int pci_parse_of_flags(u32 addr0)
 		if (addr0 & 0x40000000)
 			flags |= IORESOURCE_PREFETCH
 				 | PCI_BASE_ADDRESS_MEM_PREFETCH;
+		/* Note: We don't know whether the ROM has been left enabled
+		 * by the firmware or not. We mark it as disabled (ie, we do
+		 * not set the IORESOURCE_ROM_ENABLE flag) for now rather than
+		 * do a config space read, it will be force-enabled if needed
+		 */
+		if (!bridge && (addr0 & 0xff) == 0x30)
+			flags |= IORESOURCE_READONLY;
 	} else if (addr0 & 0x01000000)
 		flags = IORESOURCE_IO | PCI_BASE_ADDRESS_SPACE_IO;
+	if (flags)
+		flags |= IORESOURCE_SIZEALIGN;
 	return flags;
 }
 
@@ -95,7 +104,7 @@ static void pci_parse_of_addrs(struct device_node *node, struct pci_dev *dev)
 		return;
 	pr_debug("    parse addresses (%d bytes) @ %p\n", proplen, addrs);
 	for (; proplen >= 20; proplen -= 20, addrs += 5) {
-		flags = pci_parse_of_flags(addrs[0]);
+		flags = pci_parse_of_flags(addrs[0], 0);
 		if (!flags)
 			continue;
 		base = of_read_number(&addrs[1], 2);
@@ -293,7 +302,7 @@ void __devinit of_scan_pci_bridge(struct device_node *node,
 	}
 	i = 1;
 	for (; len >= 32; len -= 32, ranges += 8) {
-		flags = pci_parse_of_flags(ranges[0]);
+		flags = pci_parse_of_flags(ranges[0], 1);
 		size = of_read_number(&ranges[6], 2);
 		if (flags == 0 || size == 0)
 			continue;