spi: Move ctlr->cur_msg_prepared to struct spi_message

This enables the possibility to transfer a message that is not at the
current tip of the async message queue.
This is in preparation of the next patch(es) which enable spi_sync messages
to skip the queue altogether.

Signed-off-by: David Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220621061234.3626638-2-david@protonic.nl
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -1684,7 +1684,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
 			spi_finalize_current_message(ctlr);
 			goto out;
 		}
-		ctlr->cur_msg_prepared = true;
+		msg->prepared = true;
 	}
 
 	ret = spi_map_msg(ctlr, msg);
@@ -1926,17 +1926,18 @@ void spi_finalize_current_message(struct spi_controller *ctlr)
 	 */
 	spi_res_release(ctlr, mesg);
 
-	if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
+	if (mesg->prepared && ctlr->unprepare_message) {
 		ret = ctlr->unprepare_message(ctlr, mesg);
 		if (ret) {
 			dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
 				ret);
 		}
 	}
 
+	mesg->prepared = false;
+
 	spin_lock_irqsave(&ctlr->queue_lock, flags);
 	ctlr->cur_msg = NULL;
-	ctlr->cur_msg_prepared = false;
 	ctlr->fallback = false;
 	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 	spin_unlock_irqrestore(&ctlr->queue_lock, flags);

include/linux/spi/spi.h

@@ -385,8 +385,6 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch
  * @queue: message queue
  * @idling: the device is entering idle state
  * @cur_msg: the currently in-flight message
- * @cur_msg_prepared: spi_prepare_message was called for the currently
- *                    in-flight message
  * @cur_msg_mapped: message has been mapped for DMA
  * @last_cs: the last chip_select that is recorded by set_cs, -1 on non chip
  *           selected
@@ -621,7 +619,6 @@ struct spi_controller {
 	bool				running;
 	bool				rt;
 	bool				auto_runtime_pm;
-	bool                            cur_msg_prepared;
 	bool				cur_msg_mapped;
 	char				last_cs;
 	bool				last_cs_mode_high;
@@ -988,6 +985,7 @@ struct spi_transfer {
  * @queue: for use by whichever driver currently owns the message
  * @state: for use by whichever driver currently owns the message
  * @resources: for resource management when the spi message is processed
+ * @prepared: spi_prepare_message was called for the this message
  *
  * A @spi_message is used to execute an atomic sequence of data transfers,
  * each represented by a struct spi_transfer.  The sequence is "atomic"
@@ -1037,6 +1035,9 @@ struct spi_message {
 
 	/* list of spi_res reources when the spi message is processed */
 	struct list_head        resources;
+
+	/* spi_prepare_message was called for this message */
+	bool                    prepared;
 };
 
 static inline void spi_message_init_no_memset(struct spi_message *m)