iop-adma: P+Q support for iop13xx adma engines

iop33x support is not included because that engine is a bit more awkward
to handle in that it can either be in xor mode or pq mode.  The
dmaengine/async_tx layers currently only comprehend static capabilities.

Note iop13xx does not support hardware PQ continuation so the driver
must handle the DMA_PREP_CONTINUE flag for operations across > 16
sources. From the comment for dma_maxpq:

/* When an engine does not support native continuation we need 3 extra
 * source slots to reuse P and Q with the following coefficients:
 * 1/ {00} * P : remove P from Q', but use it as a source for P'
 * 2/ {01} * Q : use Q to continue Q' calculation
 * 3/ {00} * Q : subtract Q from P' to cancel (2)
 */

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/arm/include/asm/hardware/iop_adma.h b/arch/arm/include/asm/hardware/iop_adma.h
index 385c6e8cbbd2..bbe8a0475cad 100644
--- a/arch/arm/include/asm/hardware/iop_adma.h
+++ b/arch/arm/include/asm/hardware/iop_adma.h
@@ -106,6 +106,7 @@ struct iop_adma_desc_slot {
 	union {
 		u32 *xor_check_result;
 		u32 *crc32_result;
+		u32 *pq_check_result;
 	};
 };