ioat1: trim ioat_dma_desc_sw

Save 4 bytes per software descriptor by transmitting tx_cnt in an unused
portion of the hardware descriptor.

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

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/dma/ioat/hw.h b/drivers/dma/ioat/hw.h
index e13f3ed47763..7481fb13ce00 100644
--- a/drivers/dma/ioat/hw.h
+++ b/drivers/dma/ioat/hw.h
@@ -63,7 +63,11 @@ struct ioat_dma_descriptor {
         uint64_t        next;
         uint64_t        rsv1;
         uint64_t        rsv2;
-        uint64_t        user1;
+        /* store some driver data in an unused portion of the descriptor */
+        union {
+                uint64_t        user1;
+                uint64_t        tx_cnt;
+        };
         uint64_t        user2;
 };
 #endif