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>

7 files changed, 37 insertions, 14 deletions

diff --git a/arch/arm/include/asm/hardware/iop3xx-adma.h b/arch/arm/include/asm/hardware/iop3xx-adma.h
index 83e6ba338e2c..26eefea02314 100644
--- a/arch/arm/include/asm/hardware/iop3xx-adma.h
+++ b/arch/arm/include/asm/hardware/iop3xx-adma.h
@@ -756,13 +756,14 @@ static inline void iop_desc_set_block_fill_val(struct iop_adma_desc_slot *desc,
         hw_desc->src[0] = val;
 }
 
-static inline int iop_desc_get_zero_result(struct iop_adma_desc_slot *desc)
+static inline enum sum_check_flags
+iop_desc_get_zero_result(struct iop_adma_desc_slot *desc)
 {
         struct iop3xx_desc_aau *hw_desc = desc->hw_desc;
         struct iop3xx_aau_desc_ctrl desc_ctrl = hw_desc->desc_ctrl_field;
 
         iop_paranoia(!(desc_ctrl.tx_complete && desc_ctrl.zero_result_en));
-        return desc_ctrl.zero_result_err;
+        return desc_ctrl.zero_result_err << SUM_CHECK_P;
 }
 
 static inline void iop_chan_append(struct iop_adma_chan *chan)
diff --git a/arch/arm/mach-iop13xx/include/mach/adma.h b/arch/arm/mach-iop13xx/include/mach/adma.h
index 5722e86f2174..1cd31df8924d 100644
--- a/arch/arm/mach-iop13xx/include/mach/adma.h
+++ b/arch/arm/mach-iop13xx/include/mach/adma.h
@@ -428,18 +428,20 @@ static inline void iop_desc_set_block_fill_val(struct iop_adma_desc_slot *desc,
         hw_desc->block_fill_data = val;
 }
 
-static inline int iop_desc_get_zero_result(struct iop_adma_desc_slot *desc)
+static inline enum sum_check_flags
+iop_desc_get_zero_result(struct iop_adma_desc_slot *desc)
 {
         struct iop13xx_adma_desc_hw *hw_desc = desc->hw_desc;
         struct iop13xx_adma_desc_ctrl desc_ctrl = hw_desc->desc_ctrl_field;
         struct iop13xx_adma_byte_count byte_count = hw_desc->byte_count_field;
+        enum sum_check_flags flags;
 
         BUG_ON(!(byte_count.tx_complete && desc_ctrl.zero_result));
 
-        if (desc_ctrl.pq_xfer_en)
-                return byte_count.zero_result_err_q;
-        else
-                return byte_count.zero_result_err;
+        flags = byte_count.zero_result_err_q << SUM_CHECK_Q;
+        flags |= byte_count.zero_result_err << SUM_CHECK_P;
+
+        return flags;
 }
 
 static inline void iop_chan_append(struct iop_adma_chan *chan)
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index 1e96c4df7061..78fb7780272a 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -246,7 +246,7 @@ static int page_is_zero(struct page *p, unsigned int offset, size_t len)
  */
 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_chan *chan = async_tx_find_channel(submit, DMA_XOR_VAL,
@@ -304,7 +304,7 @@ async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
 
                 async_tx_quiesce(&tx);
 
-                *result = page_is_zero(dest, offset, len) ? 0 : 1;
+                *result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;
 
                 async_tx_sync_epilog(submit);
                 submit->flags = flags_orig;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 7727954cf726..1f2a266f3cf7 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2590,7 +2590,7 @@ static void handle_parity_checks5(raid5_conf_t *conf, struct stripe_head *sh,
                  * we are done.  Otherwise update the mismatch count and repair
                  * parity if !MD_RECOVERY_CHECK
                  */
-                if (sh->ops.zero_sum_result == 0)
+                if ((sh->ops.zero_sum_result & SUM_CHECK_P_RESULT) == 0)
                         /* parity is correct (on disc,
                          * not in buffer any more)
                          */
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index e7baabffee86..75f2c6c4cf90 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -2,6 +2,7 @@
 #define _RAID5_H
 
 #include <linux/raid/xor.h>
+#include <linux/dmaengine.h>
 
 /*
  *
@@ -215,8 +216,8 @@ struct stripe_head {
          * @target - STRIPE_OP_COMPUTE_BLK target
          */
         struct stripe_operations {
-                int                target;
-                u32                zero_sum_result;
+                int                  target;
+                enum sum_check_flags zero_sum_result;
         } ops;
         struct r5dev {
                 struct bio      req;
diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h
index 00cfb637ddf2..3d21a2517518 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 6768727d00d7..02447afcebad 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);