async_pq: kill a stray dma_map() call and other cleanups
- update the kernel doc for async_syndrome to indicate what NULL in the
source list means
- whitespace fixups
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index 43b1436..6047656 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -181,10 +181,14 @@
* blocks[disks-1] to NULL. When P or Q is omitted 'len' must be <=
* PAGE_SIZE as a temporary buffer of this size is used in the
* synchronous path. 'disks' always accounts for both destination
- * buffers.
+ * buffers. If any source buffers (blocks[i] where i < disks - 2) are
+ * set to NULL those buffers will be replaced with the raid6_zero_page
+ * in the synchronous path and omitted in the hardware-asynchronous
+ * path.
*
* 'blocks' note: if submit->scribble is NULL then the contents of
- * 'blocks' may be overridden
+ * 'blocks' may be overwritten to perform address conversions
+ * (dma_map_page() or page_address()).
*/
struct dma_async_tx_descriptor *
async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
@@ -283,13 +287,13 @@
if (!P(blocks, disks))
dma_flags |= DMA_PREP_PQ_DISABLE_P;
else
- pq[0] = dma_map_page(dev, P(blocks,disks),
+ pq[0] = dma_map_page(dev, P(blocks, disks),
offset, len,
DMA_TO_DEVICE);
if (!Q(blocks, disks))
dma_flags |= DMA_PREP_PQ_DISABLE_Q;
else
- pq[1] = dma_map_page(dev, Q(blocks,disks),
+ pq[1] = dma_map_page(dev, Q(blocks, disks),
offset, len,
DMA_TO_DEVICE);
@@ -303,9 +307,6 @@
coefs[src_cnt] = raid6_gfexp[i];
src_cnt++;
}
- pq[1] = dma_map_page(dev, Q(blocks,disks),
- offset, len,
- DMA_TO_DEVICE);
for (;;) {
tx = device->device_prep_dma_pq_val(chan, pq, dma_src,