diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 78f7b90c98f8b3930db7f5446c1f15e26b7c1c05..aab0ae33a42aae2a4ba73ab3e050754cab9ad0f5 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -12,7 +12,8 @@ CFLAGS_btext.o		+= -fPIC
 endif
 
 obj-y				:= semaphore.o cputable.o ptrace.o syscalls.o \
-				   irq.o align.o signal_32.o pmc.o vdso.o
+				   irq.o align.o signal_32.o pmc.o vdso.o \
+				   prom_parse.o
 obj-y				+= vdso32/
 obj-$(CONFIG_PPC64)		+= setup_64.o binfmt_elf32.o sys_ppc32.o \
 				   signal_64.o ptrace32.o systbl.o \
diff --git a/arch/powerpc/kernel/prom_parse.c b/arch/powerpc/kernel/prom_parse.c
new file mode 100644
index 0000000000000000000000000000000000000000..9c2a5be7a56a88e6479d823896b86b218a8607a0
--- /dev/null
+++ b/arch/powerpc/kernel/prom_parse.c
@@ -0,0 +1,420 @@
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/pci_regs.h>
+#include <linux/module.h>
+#include <asm/prom.h>
+
+#ifdef DEBUG
+#define DBG(fmt...) do { printk(fmt); } while(0)
+#else
+#define DBG(fmt...) do { } while(0)
+#endif
+
+#ifdef CONFIG_PPC64
+#define PRu64	"%lx"
+#else
+#define PRu64	"%llx"
+#endif
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+#define OF_CHECK_COUNTS(na, ns)	((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \
+			(ns) > 0)
+
+/* Debug utility */
+#ifdef DEBUG
+static void of_dump_addr(const char *s, u32 *addr, int na)
+{
+	printk("%s", s);
+	while(na--)
+		printk(" %08x", *(addr++));
+	printk("\n");
+}
+#else
+static void of_dump_addr(const char *s, u32 *addr, int na) { }
+#endif
+
+/* Read a big address */
+static inline u64 of_read_addr(u32 *cell, int size)
+{
+	u64 r = 0;
+	while (size--)
+		r = (r << 32) | *(cell++);
+	return r;
+}
+
+/* Callbacks for bus specific translators */
+struct of_bus {
+	const char	*name;
+	const char	*addresses;
+	int		(*match)(struct device_node *parent);
+	void		(*count_cells)(struct device_node *child,
+				       int *addrc, int *sizec);
+	u64		(*map)(u32 *addr, u32 *range, int na, int ns, int pna);
+	int		(*translate)(u32 *addr, u64 offset, int na);
+};
+
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_default_count_cells(struct device_node *dev,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = prom_n_addr_cells(dev);
+	if (sizec)
+		*sizec = prom_n_size_cells(dev);
+}
+
+static u64 of_default_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	cp = of_read_addr(range, na);
+	s  = of_read_addr(range + na + pna, ns);
+	da = of_read_addr(addr, na);
+
+	DBG("OF: default map, cp="PRu64", s="PRu64", da="PRu64"\n",
+	    cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_default_translate(u32 *addr, u64 offset, int na)
+{
+	u64 a = of_read_addr(addr, na);
+	memset(addr, 0, na * 4);
+	a += offset;
+	if (na > 1)
+		addr[na - 2] = a >> 32;
+	addr[na - 1] = a & 0xffffffffu;
+
+	return 0;
+}
+
+
+/*
+ * PCI bus specific translator
+ */
+
+static int of_bus_pci_match(struct device_node *np)
+{
+	return !strcmp(np->type, "pci");
+}
+
+static void of_bus_pci_count_cells(struct device_node *np,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 3;
+	if (sizec)
+		*sizec = 2;
+}
+
+static u64 of_bus_pci_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	/* Check address type match */
+	if ((addr[0] ^ range[0]) & 0x03000000)
+		return OF_BAD_ADDR;
+
+	/* Read address values, skipping high cell */
+	cp = of_read_addr(range + 1, na - 1);
+	s  = of_read_addr(range + na + pna, ns);
+	da = of_read_addr(addr + 1, na - 1);
+
+	DBG("OF: PCI map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_pci_translate(u32 *addr, u64 offset, int na)
+{
+	return of_default_translate(addr + 1, offset, na - 1);
+}
+
+/*
+ * ISA bus specific translator
+ */
+
+static int of_bus_isa_match(struct device_node *np)
+{
+	return !strcmp(np->name, "isa");
+}
+
+static void of_bus_isa_count_cells(struct device_node *child,
+				   int *addrc, int *sizec)
+{
+	if (addrc)
+		*addrc = 2;
+	if (sizec)
+		*sizec = 1;
+}
+
+static u64 of_bus_isa_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+	u64 cp, s, da;
+
+	/* Check address type match */
+	if ((addr[0] ^ range[0]) & 0x00000001)
+		return OF_BAD_ADDR;
+
+	/* Read address values, skipping high cell */
+	cp = of_read_addr(range + 1, na - 1);
+	s  = of_read_addr(range + na + pna, ns);
+	da = of_read_addr(addr + 1, na - 1);
+
+	DBG("OF: ISA map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);
+
+	if (da < cp || da >= (cp + s))
+		return OF_BAD_ADDR;
+	return da - cp;
+}
+
+static int of_bus_isa_translate(u32 *addr, u64 offset, int na)
+{
+	return of_default_translate(addr + 1, offset, na - 1);
+}
+
+/*
+ * Array of bus specific translators
+ */
+
+static struct of_bus of_busses[] = {
+	/* PCI */
+	{
+		.name = "pci",
+		.addresses = "assigned-addresses",
+		.match = of_bus_pci_match,
+		.count_cells = of_bus_pci_count_cells,
+		.map = of_bus_pci_map,
+		.translate = of_bus_pci_translate,
+	},
+	/* ISA */
+	{
+		.name = "isa",
+		.addresses = "reg",
+		.match = of_bus_isa_match,
+		.count_cells = of_bus_isa_count_cells,
+		.map = of_bus_isa_map,
+		.translate = of_bus_isa_translate,
+	},
+	/* Default */
+	{
+		.name = "default",
+		.addresses = "reg",
+		.match = NULL,
+		.count_cells = of_default_count_cells,
+		.map = of_default_map,
+		.translate = of_default_translate,
+	},
+};
+
+static struct of_bus *of_match_bus(struct device_node *np)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(of_busses); i ++)
+		if (!of_busses[i].match || of_busses[i].match(np))
+			return &of_busses[i];
+	BUG();
+	return NULL;
+}
+
+static int of_translate_one(struct device_node *parent, struct of_bus *bus,
+			    struct of_bus *pbus, u32 *addr,
+			    int na, int ns, int pna)
+{
+	u32 *ranges;
+	unsigned int rlen;
+	int rone;
+	u64 offset = OF_BAD_ADDR;
+
+	/* Normally, an absence of a "ranges" property means we are
+	 * crossing a non-translatable boundary, and thus the addresses
+	 * below the current not cannot be converted to CPU physical ones.
+	 * Unfortunately, while this is very clear in the spec, it's not
+	 * what Apple understood, and they do have things like /uni-n or
+	 * /ht nodes with no "ranges" property and a lot of perfectly
+	 * useable mapped devices below them. Thus we treat the absence of
+	 * "ranges" as equivalent to an empty "ranges" property which means
+	 * a 1:1 translation at that level. It's up to the caller not to try
+	 * to translate addresses that aren't supposed to be translated in
+	 * the first place. --BenH.
+	 */
+	ranges = (u32 *)get_property(parent, "ranges", &rlen);
+	if (ranges == NULL || rlen == 0) {
+		offset = of_read_addr(addr, na);
+		memset(addr, 0, pna);
+		goto finish;
+	}
+
+	DBG("OF: walking ranges...\n");
+
+	/* Now walk through the ranges */
+	rlen /= 4;
+	rone = na + pna + ns;
+	for (; rlen >= rone; rlen -= rone, ranges += rone) {
+		offset = bus->map(addr, ranges, na, ns, pna);
+		if (offset != OF_BAD_ADDR)
+			break;
+	}
+	if (offset == OF_BAD_ADDR) {
+		DBG("OF: not found !\n");
+		return 1;
+	}
+	memcpy(addr, ranges + na, 4 * pna);
+
+ finish:
+	of_dump_addr("OF: parent translation for:", addr, pna);
+	DBG("OF: with offset: %lx\n", offset);
+
+	/* Translate it into parent bus space */
+	return pbus->translate(addr, offset, pna);
+}
+
+
+/*
+ * Translate an address from the device-tree into a CPU physical address,
+ * this walks up the tree and applies the various bus mappings on the
+ * way.
+ *
+ * Note: We consider that crossing any level with #size-cells == 0 to mean
+ * that translation is impossible (that is we are not dealing with a value
+ * that can be mapped to a cpu physical address). This is not really specified
+ * that way, but this is traditionally the way IBM at least do things
+ */
+u64 of_translate_address(struct device_node *dev, u32 *in_addr)
+{
+	struct device_node *parent = NULL;
+	struct of_bus *bus, *pbus;
+	u32 addr[OF_MAX_ADDR_CELLS];
+	int na, ns, pna, pns;
+	u64 result = OF_BAD_ADDR;
+
+	DBG("OF: ** translation for device %s **\n", dev->full_name);
+
+	/* Increase refcount at current level */
+	of_node_get(dev);
+
+	/* Get parent & match bus type */
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		goto bail;
+	bus = of_match_bus(parent);
+
+	/* Cound address cells & copy address locally */
+	bus->count_cells(dev, &na, &ns);
+	if (!OF_CHECK_COUNTS(na, ns)) {
+		printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
+		       dev->full_name);
+		goto bail;
+	}
+	memcpy(addr, in_addr, na * 4);
+
+	DBG("OF: bus is %s (na=%d, ns=%d) on %s\n",
+	    bus->name, na, ns, parent->full_name);
+	of_dump_addr("OF: translating address:", addr, na);
+
+	/* Translate */
+	for (;;) {
+		/* Switch to parent bus */
+		of_node_put(dev);
+		dev = parent;
+		parent = of_get_parent(dev);
+
+		/* If root, we have finished */
+		if (parent == NULL) {
+			DBG("OF: reached root node\n");
+			result = of_read_addr(addr, na);
+			break;
+		}
+
+		/* Get new parent bus and counts */
+		pbus = of_match_bus(parent);
+		pbus->count_cells(dev, &pna, &pns);
+		if (!OF_CHECK_COUNTS(pna, pns)) {
+			printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
+			       dev->full_name);
+			break;
+		}
+
+		DBG("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
+		    pbus->name, pna, pns, parent->full_name);
+
+		/* Apply bus translation */
+		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna))
+			break;
+
+		/* Complete the move up one level */
+		na = pna;
+		ns = pns;
+		bus = pbus;
+
+		of_dump_addr("OF: one level translation:", addr, na);
+	}
+ bail:
+	of_node_put(parent);
+	of_node_put(dev);
+
+	return result;
+}
+EXPORT_SYMBOL(of_translate_address);
+
+u32 *of_get_address(struct device_node *dev, int index, u64 *size)
+{
+	u32 *prop;
+	unsigned int psize;
+	struct device_node *parent;
+	struct of_bus *bus;
+	int onesize, i, na, ns;
+
+	/* Get parent & match bus type */
+	parent = of_get_parent(dev);
+	if (parent == NULL)
+		return NULL;
+	bus = of_match_bus(parent);
+	bus->count_cells(dev, &na, &ns);
+	of_node_put(parent);
+	if (!OF_CHECK_COUNTS(na, ns))
+		return NULL;
+
+	/* Get "reg" or "assigned-addresses" property */
+	prop = (u32 *)get_property(dev, bus->addresses, &psize);
+	if (prop == NULL)
+		return NULL;
+	psize /= 4;
+
+	onesize = na + ns;
+	for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
+		if (i == index) {
+			if (size)
+				*size = of_read_addr(prop + na, ns);
+			return prop;
+		}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_address);
+
+u32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size)
+{
+	u32 *addr;
+	int index;
+
+	for (index = 0; (addr = of_get_address(dev, index, size)) != NULL;
+	     index++) {
+		if ((addr[0] & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0))
+			return addr;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(of_get_pci_address);
diff --git a/include/asm-powerpc/mmu.h b/include/asm-powerpc/mmu.h
index 29b0bb0086d3fc5f40e8848d82662c345d4a4a44..29613500c2c247ef781eb844ece84342da680efc 100644
--- a/include/asm-powerpc/mmu.h
+++ b/include/asm-powerpc/mmu.h
@@ -394,6 +394,10 @@ static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
 #define VSID_SCRAMBLE(pvsid)	(((pvsid) * VSID_MULTIPLIER) % VSID_MODULUS)
 #define KERNEL_VSID(ea)		VSID_SCRAMBLE(GET_ESID(ea))
 
+/* Physical address used by some IO functions */
+typedef unsigned long phys_addr_t;
+
+
 #endif /* __ASSEMBLY */
 
 #endif /* CONFIG_PPC64 */
diff --git a/include/asm-powerpc/prom.h b/include/asm-powerpc/prom.h
index f999df1c5c90bc18c994fe4e83b3b2cb4b1f9e57..fb732c992bd289adfbae36501c556af2e9db2215 100644
--- a/include/asm-powerpc/prom.h
+++ b/include/asm-powerpc/prom.h
@@ -223,5 +223,14 @@ extern struct resource *request_OF_resource(struct device_node* node,
 				int index, const char* name_postfix);
 extern int release_OF_resource(struct device_node* node, int index);
 
+/*
+ * Address translation function(s)
+ */
+#define OF_BAD_ADDR	((u64)-1)
+extern u64 of_translate_address(struct device_node *np, u32 *addr);
+extern u32 *of_get_address(struct device_node *dev, int index, u64 *size);
+extern u32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size);
+
+
 #endif /* __KERNEL__ */
 #endif /* _POWERPC_PROM_H */
diff --git a/include/asm-ppc/prom.h b/include/asm-ppc/prom.h
index 3e39827ed56690bace2991437a6082fdddd88f34..a10a2d64b300ba897d95247caf43094255ba53c0 100644
--- a/include/asm-ppc/prom.h
+++ b/include/asm-ppc/prom.h
@@ -136,5 +136,15 @@ extern unsigned long sub_reloc_offset(unsigned long);
 #define PTRRELOC(x)	((typeof(x))add_reloc_offset((unsigned long)(x)))
 #define PTRUNRELOC(x)	((typeof(x))sub_reloc_offset((unsigned long)(x)))
 
+
+/*
+ * Address translation function(s)
+ */
+#define OF_BAD_ADDR	((u64)-1)
+extern u64 of_translate_address(struct device_node *np, u32 *addr);
+extern u32 *of_get_address(struct device_node *dev, int index, u64 *size);
+extern u32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size);
+
+
 #endif /* _PPC_PROM_H */
 #endif /* __KERNEL__ */