USB: remove uses of URB_NO_SETUP_DMA_MAP

This patch (as1350) removes all usages of coherent buffers for USB
control-request setup-packet buffers.  There's no good reason to
reserve coherent memory for these things; control requests are hardly
ever used in large quantity (the major exception is firmware
transfers, and they aren't time-critical).  Furthermore, only seven
drivers used it.  We might as well always use streaming DMA mappings
for setup-packet buffers, and remove some extra complexity from
usbcore.

The DMA-mapping portion of hcd.c is currently in flux.  A separate
patch will be submitted to remove support for URB_NO_SETUP_DMA_MAP
after everything else settles down.  The removal should go smoothly,
as by then nobody will be using it.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

7 files changed, 13 insertions, 40 deletions

diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 09301f4b7225..2532a0917f8c 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -396,8 +396,8 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 		return -EPIPE;		/* The most suitable error code :-) */
 
 	/* enforce simple/standard policy */
-	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP |
-			URB_NO_INTERRUPT | URB_DIR_MASK | URB_FREE_BUFFER);
+	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT | URB_DIR_MASK |
+			URB_FREE_BUFFER);
 	switch (xfertype) {
 	case USB_ENDPOINT_XFER_BULK:
 		if (is_out)
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 1088abb4416c..097172e2ba06 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -775,7 +775,7 @@ EXPORT_SYMBOL_GPL(usb_free_coherent);
  * @urb: urb whose transfer_buffer/setup_packet will be mapped
  *
  * Return value is either null (indicating no buffer could be mapped), or
- * the parameter.  URB_NO_TRANSFER_DMA_MAP and URB_NO_SETUP_DMA_MAP are
+ * the parameter.  URB_NO_TRANSFER_DMA_MAP is
  * added to urb->transfer_flags if the operation succeeds.  If the device
  * is connected to this system through a non-DMA controller, this operation
  * always succeeds.
@@ -803,17 +803,11 @@ struct urb *usb_buffer_map(struct urb *urb)
 			urb->transfer_buffer, urb->transfer_buffer_length,
 			usb_pipein(urb->pipe)
 				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
-		if (usb_pipecontrol(urb->pipe))
-			urb->setup_dma = dma_map_single(controller,
-					urb->setup_packet,
-					sizeof(struct usb_ctrlrequest),
-					DMA_TO_DEVICE);
 	/* FIXME generic api broken like pci, can't report errors */
 	/* if (urb->transfer_dma == DMA_ADDR_INVALID) return 0; */
 	} else
 		urb->transfer_dma = ~0;
-	urb->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP
-				| URB_NO_SETUP_DMA_MAP);
+	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	return urb;
 }
 EXPORT_SYMBOL_GPL(usb_buffer_map);
@@ -881,14 +875,8 @@ void usb_buffer_unmap(struct urb *urb)
 			urb->transfer_dma, urb->transfer_buffer_length,
 			usb_pipein(urb->pipe)
 				? DMA_FROM_DEVICE : DMA_TO_DEVICE);
-		if (usb_pipecontrol(urb->pipe))
-			dma_unmap_single(controller,
-					urb->setup_dma,
-					sizeof(struct usb_ctrlrequest),
-					DMA_TO_DEVICE);
 	}
-	urb->transfer_flags &= ~(URB_NO_TRANSFER_DMA_MAP
-				| URB_NO_SETUP_DMA_MAP);
+	urb->transfer_flags &= ~URB_NO_TRANSFER_DMA_MAP;
 }
 EXPORT_SYMBOL_GPL(usb_buffer_unmap);
 #endif  /*  0  */
diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index a21cce6f7403..9dcc82337ced 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -977,15 +977,13 @@ test_ctrl_queue (struct usbtest_dev *dev, struct usbtest_param *param)
 		if (!u)
 			goto cleanup;
 
-		reqp = usb_buffer_alloc (udev, sizeof *reqp, GFP_KERNEL,
-				&u->setup_dma);
+		reqp = kmalloc(sizeof *reqp, GFP_KERNEL);
 		if (!reqp)
 			goto cleanup;
 		reqp->setup = req;
 		reqp->number = i % NUM_SUBCASES;
 		reqp->expected = expected;
 		u->setup_packet = (char *) &reqp->setup;
-		u->transfer_flags |= URB_NO_SETUP_DMA_MAP;
 
 		u->context = &context;
 		u->complete = ctrl_complete;
@@ -1017,10 +1015,7 @@ cleanup:
 		if (!urb [i])
 			continue;
 		urb [i]->dev = udev;
-		if (urb [i]->setup_packet)
-			usb_buffer_free (udev, sizeof (struct usb_ctrlrequest),
-					urb [i]->setup_packet,
-					urb [i]->setup_dma);
+		kfree(urb[i]->setup_packet);
 		simple_free_urb (urb [i]);
 	}
 	kfree (urb);
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index f253edec3bb8..44716427c51c 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -147,11 +147,9 @@ static int usb_stor_msg_common(struct us_data *us, int timeout)
 	 * hasn't been mapped for DMA.  Yes, this is clunky, but it's
 	 * easier than always having the caller tell us whether the
 	 * transfer buffer has already been mapped. */
-	us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
 	if (us->current_urb->transfer_buffer == us->iobuf)
 		us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	us->current_urb->transfer_dma = us->iobuf_dma;
-	us->current_urb->setup_dma = us->cr_dma;
 
 	/* submit the URB */
 	status = usb_submit_urb(us->current_urb, GFP_NOIO);
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index bbeeb92a2131..c54a370c76c5 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -407,9 +407,8 @@ static int associate_dev(struct us_data *us, struct usb_interface *intf)
 	/* Store our private data in the interface */
 	usb_set_intfdata(intf, us);
 
-	/* Allocate the device-related DMA-mapped buffers */
-	us->cr = usb_buffer_alloc(us->pusb_dev, sizeof(*us->cr),
-			GFP_KERNEL, &us->cr_dma);
+	/* Allocate the control/setup and DMA-mapped buffers */
+	us->cr = kmalloc(sizeof(*us->cr), GFP_KERNEL);
 	if (!us->cr) {
 		US_DEBUGP("usb_ctrlrequest allocation failed\n");
 		return -ENOMEM;
@@ -757,13 +756,9 @@ static void dissociate_dev(struct us_data *us)
 {
 	US_DEBUGP("-- %s\n", __func__);
 
-	/* Free the device-related DMA-mapped buffers */
-	if (us->cr)
-		usb_buffer_free(us->pusb_dev, sizeof(*us->cr), us->cr,
-				us->cr_dma);
-	if (us->iobuf)
-		usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf,
-				us->iobuf_dma);
+	/* Free the buffers */
+	kfree(us->cr);
+	usb_buffer_free(us->pusb_dev, US_IOBUF_SIZE, us->iobuf, us->iobuf_dma);
 
 	/* Remove our private data from the interface */
 	usb_set_intfdata(us->pusb_intf, NULL);
diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index 69717134231b..89d3bfff98df 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -139,8 +139,7 @@ struct us_data {
 	struct usb_ctrlrequest	*cr;		 /* control requests	 */
 	struct usb_sg_request	current_sg;	 /* scatter-gather req.  */
 	unsigned char		*iobuf;		 /* I/O buffer		 */
-	dma_addr_t		cr_dma;		 /* buffer DMA addresses */
-	dma_addr_t		iobuf_dma;
+	dma_addr_t		iobuf_dma;	 /* buffer DMA addresses */
 	struct task_struct	*ctl_thread;	 /* the control thread   */
 
 	/* mutual exclusion and synchronization structures */
diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c
index 112ef7e26f6b..2ce6b7eccc6a 100644
--- a/drivers/usb/wusbcore/wa-xfer.c
+++ b/drivers/usb/wusbcore/wa-xfer.c
@@ -474,8 +474,6 @@ static void __wa_xfer_setup_hdr0(struct wa_xfer *xfer,
 		struct wa_xfer_ctl *xfer_ctl =
 			container_of(xfer_hdr0, struct wa_xfer_ctl, hdr);
 		xfer_ctl->bmAttribute = xfer->is_inbound ? 1 : 0;
-		BUG_ON(xfer->urb->transfer_flags & URB_NO_SETUP_DMA_MAP
-		       && xfer->urb->setup_packet == NULL);
 		memcpy(&xfer_ctl->baSetupData, xfer->urb->setup_packet,
 		       sizeof(xfer_ctl->baSetupData));
 		break;