void *usb_alloc_coherent(struct usb_device *dev, size_t size,
gfp_t mem_flags, dma_addr_t *dma);
void usb_free_coherent(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_free_coherent(struct usb_device *dev, size_t size,