usb: dwc2: Fix DMA cache alignment issues

Insert a padding between data and the stored_xfer_buffer pointer to
ensure they are not on the same cache line.

Otherwise, the stored_xfer_buffer gets corrupted for IN URBs on
non-cache-coherent systems. (In my case: Lantiq xRX200 MIPS)

Fixes: 3bc04e28a0 ("usb: dwc2: host: Get aligned DMA in a more supported way")
Fixes: 56406e017a ("usb: dwc2: Fix DMA alignment to start at allocated boundary")
Cc: <stable@vger.kernel.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
This commit is contained in:
Martin Schiller 2019-02-18 07:37:30 +01:00 committed by Felipe Balbi
parent babd183915
commit 4a4863bf2e

View File

@ -2480,8 +2480,10 @@ static void dwc2_free_dma_aligned_buffer(struct urb *urb)
return;
/* Restore urb->transfer_buffer from the end of the allocated area */
memcpy(&stored_xfer_buffer, urb->transfer_buffer +
urb->transfer_buffer_length, sizeof(urb->transfer_buffer));
memcpy(&stored_xfer_buffer,
PTR_ALIGN(urb->transfer_buffer + urb->transfer_buffer_length,
dma_get_cache_alignment()),
sizeof(urb->transfer_buffer));
if (usb_urb_dir_in(urb)) {
if (usb_pipeisoc(urb->pipe))
@ -2513,6 +2515,7 @@ static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
* DMA
*/
kmalloc_size = urb->transfer_buffer_length +
(dma_get_cache_alignment() - 1) +
sizeof(urb->transfer_buffer);
kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
@ -2523,7 +2526,8 @@ static int dwc2_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
* Position value of original urb->transfer_buffer pointer to the end
* of allocation for later referencing
*/
memcpy(kmalloc_ptr + urb->transfer_buffer_length,
memcpy(PTR_ALIGN(kmalloc_ptr + urb->transfer_buffer_length,
dma_get_cache_alignment()),
&urb->transfer_buffer, sizeof(urb->transfer_buffer));
if (usb_urb_dir_out(urb))