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Subject[PATCH 4.14 43/53] usb: dwc2: Fix DMA cache alignment issues
Date
From: Martin Schiller <ms@dev.tdt.de>

commit 4a4863bf2e7932e584a3a462d3c6daf891142ddc upstream.

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: 3bc04e28a030 ("usb: dwc2: host: Get aligned DMA in a more supported way")
Fixes: 56406e017a88 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/dwc2/hcd.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -2652,8 +2652,10 @@ static void dwc2_free_dma_aligned_buffer
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))
memcpy(stored_xfer_buffer, urb->transfer_buffer,
@@ -2680,6 +2682,7 @@ static int dwc2_alloc_dma_aligned_buffer
* DMA
*/
kmalloc_size = urb->transfer_buffer_length +
+ (dma_get_cache_alignment() - 1) +
sizeof(urb->transfer_buffer);

kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
@@ -2690,7 +2693,8 @@ static int dwc2_alloc_dma_aligned_buffer
* 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))

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