usb gadget stack: remove usb_ep_*_buffer(), part 1

Remove usb_ep_{alloc,free}_buffer() calls, for small dma-coherent buffers.
This patch just removes the interface and its users; later patches will
remove controller driver support.

  - This interface is invariably not implemented correctly in the
    controller drivers (e.g. using dma pools, a mechanism which
    post-dates the interface by several years).

  - At this point no gadget driver really *needs* to use it.  In
    current kernels, any driver that needs such a mechanism could
    allocate a dma pool themselves.

Removing this interface is thus a simplification and improvement.

Note that the gmidi.c driver had a bug in this area; fixed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 7e650d0..8712ef9 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -3733,19 +3733,12 @@
 	}
 
 	/* Free the data buffers */
-	for (i = 0; i < NUM_BUFFERS; ++i) {
-		struct fsg_buffhd	*bh = &fsg->buffhds[i];
-
-		if (bh->buf)
-			usb_ep_free_buffer(fsg->bulk_in, bh->buf, bh->dma,
-					mod_data.buflen);
-	}
+	for (i = 0; i < NUM_BUFFERS; ++i)
+		kfree(fsg->buffhds[i].buf);
 
 	/* Free the request and buffer for endpoint 0 */
 	if (req) {
-		if (req->buf)
-			usb_ep_free_buffer(fsg->ep0, req->buf,
-					req->dma, EP0_BUFSIZE);
+		kfree(req->buf);
 		usb_ep_free_request(fsg->ep0, req);
 	}
 
@@ -3972,8 +3965,7 @@
 	fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
 	if (!req)
 		goto out;
-	req->buf = usb_ep_alloc_buffer(fsg->ep0, EP0_BUFSIZE,
-			&req->dma, GFP_KERNEL);
+	req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
 	if (!req->buf)
 		goto out;
 	req->complete = ep0_complete;
@@ -3985,8 +3977,7 @@
 		/* Allocate for the bulk-in endpoint.  We assume that
 		 * the buffer will also work with the bulk-out (and
 		 * interrupt-in) endpoint. */
-		bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
-				&bh->dma, GFP_KERNEL);
+		bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
 		if (!bh->buf)
 			goto out;
 		bh->next = bh + 1;