Commit a06d568f authored by Dan Williams's avatar Dan Williams
Browse files

async_xor: dma_map destination DMA_BIDIRECTIONAL 



Mapping the destination multiple times is a misuse of the dma-api.
Since the destination may be reused as a source, ensure that it is only
mapped once and that it is mapped bidirectionally.  This appears to add
ugliness on the unmap side in that it always reads back the destination
address from the descriptor, but gcc can determine that dma_unmap is a
nop and not emit the code that calculates its arguments.

Cc: <stable@kernel.org>
Cc: Saeed Bishara <saeed@marvell.com>
Acked-by: default avatarYuri Tikhonov <yur@emcraft.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent b0b42b16

crypto/async_tx/async_xor.c

+9 −2
Original line number Diff line number Diff line
@@ -53,10 +53,17 @@ do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list, 
	int xor_src_cnt;

	dma_addr_t dma_dest;



	dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_FROM_DEVICE);

	for (i = 0; i < src_cnt; i++)

	/* map the dest bidrectional in case it is re-used as a source */

	dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);

	for (i = 0; i < src_cnt; i++) {

		/* only map the dest once */

		if (unlikely(src_list[i] == dest)) {

			dma_src[i] = dma_dest;

			continue;

		}

		dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,

					  len, DMA_TO_DEVICE);

	}



	while (src_cnt) {

		async_flags = flags;

drivers/dma/iop-adma.c

+13 −3
Original line number Diff line number Diff line
@@ -85,18 +85,28 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc, 
			enum dma_ctrl_flags flags = desc->async_tx.flags;

			u32 src_cnt;

			dma_addr_t addr;

			dma_addr_t dest;



			src_cnt = unmap->unmap_src_cnt;

			dest = iop_desc_get_dest_addr(unmap, iop_chan);

			if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {

				addr = iop_desc_get_dest_addr(unmap, iop_chan);

				dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);

				enum dma_data_direction dir;



				if (src_cnt > 1) /* is xor? */

					dir = DMA_BIDIRECTIONAL;

				else

					dir = DMA_FROM_DEVICE;



				dma_unmap_page(dev, dest, len, dir);

			}



			if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {

				src_cnt = unmap->unmap_src_cnt;

				while (src_cnt--) {

					addr = iop_desc_get_src_addr(unmap,

								     iop_chan,

								     src_cnt);

					if (addr == dest)

						continue;

					dma_unmap_page(dev, addr, len,

						       DMA_TO_DEVICE);

				}

drivers/dma/mv_xor.c

+12 −3
Original line number Diff line number Diff line
@@ -311,17 +311,26 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc, 
			enum dma_ctrl_flags flags = desc->async_tx.flags;

			u32 src_cnt;

			dma_addr_t addr;

			dma_addr_t dest;



			src_cnt = unmap->unmap_src_cnt;

			dest = mv_desc_get_dest_addr(unmap);

			if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {

				addr = mv_desc_get_dest_addr(unmap);

				dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);

				enum dma_data_direction dir;



				if (src_cnt > 1) /* is xor ? */

					dir = DMA_BIDIRECTIONAL;

				else

					dir = DMA_FROM_DEVICE;

				dma_unmap_page(dev, dest, len, dir);

			}



			if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {

				src_cnt = unmap->unmap_src_cnt;

				while (src_cnt--) {

					addr = mv_desc_get_src_addr(unmap,

								    src_cnt);

					if (addr == dest)

						continue;

					dma_unmap_page(dev, addr, len,

						       DMA_TO_DEVICE);

				}

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