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>

drivers/usb/core/usb.c

@@ -718,7 +718,7 @@ int __usb_get_extra_descriptor(char *buffer, unsigned size,
 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
@@ -737,29 +737,29 @@ EXPORT_SYMBOL_GPL(__usb_get_extra_descriptor);
  * 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,
+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,
+void usb_free_coherent(struct usb_device *dev, size_t size, void *addr,
 		       dma_addr_t dma)
 {
 	if (!dev || !dev->bus)
@@ -768,7 +768,7 @@ void usb_buffer_free(struct usb_device *dev, size_t size, void *addr,
 		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

include/linux/usb.h

@@ -1085,7 +1085,7 @@ typedef void (*usb_complete_t)(struct urb *);
  * Alternatively, drivers may pass the URB_NO_xxx_DMA_MAP transfer flags,
  * which tell the host controller driver that no such mapping is needed since
  * the device driver is DMA-aware.  For example, a device driver might
- * allocate a DMA buffer with usb_buffer_alloc() or call usb_buffer_map().
+ * allocate a DMA buffer with usb_alloc_coherent() or call usb_buffer_map().
  * When these transfer flags are provided, host controller drivers will
  * attempt to use the dma addresses found in the transfer_dma and/or
  * setup_dma fields rather than determining a dma address themselves.
@@ -1366,11 +1366,23 @@ static inline int usb_urb_dir_out(struct urb *urb)
 	return (urb->transfer_flags & URB_DIR_MASK) == URB_DIR_OUT;
 }
 
-void *usb_buffer_alloc(struct usb_device *dev, size_t size,
+void *usb_alloc_coherent(struct usb_device *dev, size_t size,
 	gfp_t mem_flags, dma_addr_t *dma);
-void usb_buffer_free(struct usb_device *dev, size_t size,
+void usb_free_coherent(struct usb_device *dev, size_t size,
 	void *addr, dma_addr_t dma);
 
+/* Compatible macros while we switch over */
+static inline void *usb_buffer_alloc(struct usb_device *dev, size_t size,
+				     gfp_t mem_flags, dma_addr_t *dma)
+{
+	return usb_alloc_coherent(dev, size, mem_flags, dma);
+}
+static inline void usb_buffer_free(struct usb_device *dev, size_t size,
+				   void *addr, dma_addr_t dma)
+{
+	return usb_free_coherent(dev, size, addr, dma);
+}
+
 #if 0
 struct urb *usb_buffer_map(struct urb *urb);
 void usb_buffer_dmasync(struct urb *urb);