[POWERPC] Add of_translate_dma_address

This adds a variant of of_translate_address that uses the dma-ranges
property instead of "ranges", it's to be used by PCI code in parsing
the dma-ranges property.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/prom_parse.c

@@ -419,7 +419,7 @@ static struct of_bus *of_match_bus(struct device_node *np)
 
 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)
+			    int na, int ns, int pna, const char *rprop)
 {
 	const u32 *ranges;
 	unsigned int rlen;
@@ -438,7 +438,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 	 * to translate addresses that aren't supposed to be translated in
 	 * the first place. --BenH.
 	 */
-	ranges = of_get_property(parent, "ranges", &rlen);
+	ranges = of_get_property(parent, rprop, &rlen);
 	if (ranges == NULL || rlen == 0) {
 		offset = of_read_number(addr, na);
 		memset(addr, 0, pna * 4);
@@ -481,7 +481,8 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
  * 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, const u32 *in_addr)
+u64 __of_translate_address(struct device_node *dev, const u32 *in_addr,
+			   const char *rprop)
 {
 	struct device_node *parent = NULL;
 	struct of_bus *bus, *pbus;
@@ -540,7 +541,7 @@ u64 of_translate_address(struct device_node *dev, const u32 *in_addr)
 		    pbus->name, pna, pns, parent->full_name);
 
 		/* Apply bus translation */
-		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna))
+		if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
 			break;
 
 		/* Complete the move up one level */
@@ -556,8 +557,19 @@ u64 of_translate_address(struct device_node *dev, const u32 *in_addr)
 
 	return result;
 }
+
+u64 of_translate_address(struct device_node *dev, const u32 *in_addr)
+{
+	return __of_translate_address(dev, in_addr, "ranges");
+}
 EXPORT_SYMBOL(of_translate_address);
 
+u64 of_translate_dma_address(struct device_node *dev, const u32 *in_addr)
+{
+	return __of_translate_address(dev, in_addr, "dma-ranges");
+}
+EXPORT_SYMBOL(of_translate_dma_address);
+
 const u32 *of_get_address(struct device_node *dev, int index, u64 *size,
 		    unsigned int *flags)
 {

include/asm-powerpc/prom.h

@@ -202,6 +202,10 @@ static inline unsigned long of_read_ulong(const u32 *cell, int size)
  */
 extern u64 of_translate_address(struct device_node *np, const u32 *addr);
 
+/* Translate a DMA address from device space to CPU space */
+extern u64 of_translate_dma_address(struct device_node *dev,
+				    const u32 *in_addr);
+
 /* Extract an address from a device, returns the region size and
  * the address space flags too. The PCI version uses a BAR number
  * instead of an absolute index