async_tx: add sum check flags

Replace the flat zero_sum_result with a collection of flags to contain
the P (xor) zero-sum result, and the soon to be utilized Q (raid6 reed
solomon syndrome) zero-sum result.  Use the SUM_CHECK_ namespace instead
of DMA_ since these flags will be used on non-dma-zero-sum enabled
platforms.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 21 insertions, 2 deletions

diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h
index 00cfb637ddf..3d21a251751 100644
--- a/include/linux/async_tx.h
+++ b/include/linux/async_tx.h
@@ -148,7 +148,7 @@ async_xor(struct page *dest, struct page **src_list, unsigned int offset,
 
 struct dma_async_tx_descriptor *
 async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
-	      int src_cnt, size_t len, u32 *result,
+	      int src_cnt, size_t len, enum sum_check_flags *result,
 	      struct async_submit_ctl *submit);
 
 struct dma_async_tx_descriptor *
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 6768727d00d..02447afceba 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -87,6 +87,25 @@ enum dma_ctrl_flags {
 };
 
 /**
+ * enum sum_check_bits - bit position of pq_check_flags
+ */
+enum sum_check_bits {
+	SUM_CHECK_P = 0,
+	SUM_CHECK_Q = 1,
+};
+
+/**
+ * enum pq_check_flags - result of async_{xor,pq}_zero_sum operations
+ * @SUM_CHECK_P_RESULT - 1 if xor zero sum error, 0 otherwise
+ * @SUM_CHECK_Q_RESULT - 1 if reed-solomon zero sum error, 0 otherwise
+ */
+enum sum_check_flags {
+	SUM_CHECK_P_RESULT = (1 << SUM_CHECK_P),
+	SUM_CHECK_Q_RESULT = (1 << SUM_CHECK_Q),
+};
+
+
+/**
  * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
  * See linux/cpumask.h
  */
@@ -245,7 +264,7 @@ struct dma_device {
 		unsigned int src_cnt, size_t len, unsigned long flags);
 	struct dma_async_tx_descriptor *(*device_prep_dma_xor_val)(
 		struct dma_chan *chan, dma_addr_t *src,	unsigned int src_cnt,
-		size_t len, u32 *result, unsigned long flags);
+		size_t len, enum sum_check_flags *result, unsigned long flags);
 	struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
 		struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
 		unsigned long flags);