dmaengine: kill tx_list

The tx_list attribute of struct dma_async_tx_descriptor is common to
most, but not all dma driver implementations.  None of the upper level
code (dmaengine/async_tx) uses it, so allow drivers to implement it
locally if they need it.  This saves sizeof(struct list_head) bytes for
drivers that do not manage descriptors with a linked list (e.g.: ioatdma
v2,3).

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

1 files changed, 0 insertions, 3 deletions

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index ffefba81c818..f114bc7790bc 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -180,8 +180,6 @@ typedef void (*dma_async_tx_callback)(void *dma_async_param);
  * @flags: flags to augment operation preparation, control completion, and
  *      communicate status
  * @phys: physical address of the descriptor
- * @tx_list: driver common field for operations that require multiple
- *      descriptors
  * @chan: target channel for this operation
  * @tx_submit: set the prepared descriptor(s) to be executed by the engine
  * @callback: routine to call after this operation is complete
@@ -195,7 +193,6 @@ struct dma_async_tx_descriptor {
         dma_cookie_t cookie;
         enum dma_ctrl_flags flags; /* not a 'long' to pack with cookie */
         dma_addr_t phys;
-        struct list_head tx_list;
         struct dma_chan *chan;
         dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
         dma_async_tx_callback callback;