USB: rename usb_buffer_alloc() and usb_buffer_free()

For more clearance what the functions actually do,

  usb_buffer_alloc() is renamed to usb_alloc_coherent()
  usb_buffer_free()  is renamed to usb_free_coherent()

They should only be used in code which really needs DMA coherency.

[added compatibility macros so we can convert things easier - gregkh]

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Pedro Ribeiro <pedrib@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 1297e9b..0561430 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -718,7 +718,7 @@
 EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
 
 /**
- * usb_buffer_alloc - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
+ * usb_alloc_coherent - allocate dma-consistent buffer for URB_NO_xxx_DMA_MAP
  * @dev: device the buffer will be used with
  * @size: requested buffer size
  * @mem_flags: affect whether allocation may block
@@ -737,30 +737,30 @@
  * architectures where CPU caches are not DMA-coherent.  On systems without
  * bus-snooping caches, these buffers are uncached.
  *
- * When the buffer is no longer used, free it with usb_buffer_free().
+ * When the buffer is no longer used, free it with usb_free_coherent().
  */
-void *usb_buffer_alloc(struct usb_device *dev, size_t size, gfp_t mem_flags,
-		       dma_addr_t *dma)
+void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
+			 dma_addr_t *dma)
 {
 	if (!dev || !dev->bus)
 		return NULL;
 	return hcd_buffer_alloc(dev->bus, size, mem_flags, dma);
 }
-EXPORT_SYMBOL_GPL(usb_buffer_alloc);
+EXPORT_SYMBOL_GPL(usb_alloc_coherent);
 
 /**
- * usb_buffer_free - free memory allocated with usb_buffer_alloc()
+ * usb_free_coherent - free memory allocated with usb_alloc_coherent()
  * @dev: device the buffer was used with
  * @size: requested buffer size
  * @addr: CPU address of buffer
  * @dma: DMA address of buffer
  *
  * This reclaims an I/O buffer, letting it be reused.  The memory must have
- * been allocated using usb_buffer_alloc(), and the parameters must match
+ * been allocated using usb_alloc_coherent(), and the parameters must match
  * those provided in that allocation request.
  */
-void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
-		     dma_addr_t dma)
+void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
+		       dma_addr_t dma)
 {
 	if (!dev || !dev->bus)
 		return;
@@ -768,7 +768,7 @@
 		return;
 	hcd_buffer_free(dev->bus, size, addr, dma);
 }
-EXPORT_SYMBOL_GPL(usb_buffer_free);
+EXPORT_SYMBOL_GPL(usb_free_coherent);
 
 /**
  * usb_buffer_map - create DMA mapping(s) for an urb