async_tx: structify submission arguments, add scribble

Prepare the api for the arrival of a new parameter, 'scribble'.  This
will allow callers to identify scratchpad memory for dma address or page
address conversions.  As this adds yet another parameter, take this
opportunity to convert the common submission parameters (flags,
dependency, callback, and callback argument) into an object that is
passed by reference.

Also, take this opportunity to fix up the kerneldoc and add notes about
the relevant ASYNC_TX_* flags for each routine.

[ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]

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

1 files changed, 27 insertions, 24 deletions

diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 3766bc3d7d89..802a5ce437d9 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -45,13 +45,15 @@ static void __exit async_tx_exit(void)
 /**
  * __async_tx_find_channel - find a channel to carry out the operation or let
  *      the transaction execute synchronously
- * @depend_tx: transaction dependency
+ * @submit: transaction dependency and submission modifiers
  * @tx_type: transaction type
  */
 struct dma_chan *
-__async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
-        enum dma_transaction_type tx_type)
+__async_tx_find_channel(struct async_submit_ctl *submit,
+                        enum dma_transaction_type tx_type)
 {
+        struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
+
         /* see if we can keep the chain on one channel */
         if (depend_tx &&
             dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
@@ -144,13 +146,14 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
 
 
 /**
- * submit_disposition - while holding depend_tx->lock we must avoid submitting
- *      new operations to prevent a circular locking dependency with
- *      drivers that already hold a channel lock when calling
- *      async_tx_run_dependencies.
+ * submit_disposition - flags for routing an incoming operation
  * @ASYNC_TX_SUBMITTED: we were able to append the new operation under the lock
  * @ASYNC_TX_CHANNEL_SWITCH: when the lock is dropped schedule a channel switch
  * @ASYNC_TX_DIRECT_SUBMIT: when the lock is dropped submit directly
+ *
+ * while holding depend_tx->lock we must avoid submitting new operations
+ * to prevent a circular locking dependency with drivers that already
+ * hold a channel lock when calling async_tx_run_dependencies.
  */
 enum submit_disposition {
         ASYNC_TX_SUBMITTED,
@@ -160,11 +163,12 @@ enum submit_disposition {
 
 void
 async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
-        enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
-        dma_async_tx_callback cb_fn, void *cb_param)
+                struct async_submit_ctl *submit)
 {
-        tx->callback = cb_fn;
-        tx->callback_param = cb_param;
+        struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
+
+        tx->callback = submit->cb_fn;
+        tx->callback_param = submit->cb_param;
 
         if (depend_tx) {
                 enum submit_disposition s;
@@ -220,7 +224,7 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
                 tx->tx_submit(tx);
         }
 
-        if (flags & ASYNC_TX_ACK)
+        if (submit->flags & ASYNC_TX_ACK)
                 async_tx_ack(tx);
 
         if (depend_tx)
@@ -229,21 +233,20 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
 EXPORT_SYMBOL_GPL(async_tx_submit);
 
 /**
- * async_trigger_callback - schedules the callback function to be run after
- * any dependent operations have been completed.
- * @flags: ASYNC_TX_ACK
- * @depend_tx: 'callback' requires the completion of this transaction
- * @cb_fn: function to call after depend_tx completes
- * @cb_param: parameter to pass to the callback routine
+ * async_trigger_callback - schedules the callback function to be run
+ * @submit: submission and completion parameters
+ *
+ * honored flags: ASYNC_TX_ACK
+ *
+ * The callback is run after any dependent operations have completed.
  */
 struct dma_async_tx_descriptor *
-async_trigger_callback(enum async_tx_flags flags,
-        struct dma_async_tx_descriptor *depend_tx,
-        dma_async_tx_callback cb_fn, void *cb_param)
+async_trigger_callback(struct async_submit_ctl *submit)
 {
         struct dma_chan *chan;
         struct dma_device *device;
         struct dma_async_tx_descriptor *tx;
+        struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
 
         if (depend_tx) {
                 chan = depend_tx->chan;
@@ -262,14 +265,14 @@ async_trigger_callback(enum async_tx_flags flags,
         if (tx) {
                 pr_debug("%s: (async)\n", __func__);
 
-                async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+                async_tx_submit(chan, tx, submit);
         } else {
                 pr_debug("%s: (sync)\n", __func__);
 
                 /* wait for any prerequisite operations */
-                async_tx_quiesce(&depend_tx);
+                async_tx_quiesce(&submit->depend_tx);
 
-                async_tx_sync_epilog(cb_fn, cb_param);
+                async_tx_sync_epilog(submit);
         }
 
         return tx;