ide: add ->dma_timer_expiry method and remove ->dma_exec_cmd one (v2)

* Rename dma_timer_expiry() to ide_dma_sff_timer_expiry() and export it.

* Add ->dma_timer_expiry method and use it to set hwif->expiry for
  ATA_PROT_DMA protocol in do_rw_taskfile().

* Initialize ->dma_timer_expiry to ide_dma_sff_timer_expiry() for SFF hosts.

* Move setting hwif->expiry from ide_execute_command() to its users and drop
  'expiry' argument.

* Use ide_execute_command() instead of ->dma_exec_cmd in do_rw_taskfile().

* Remove ->dma_exec_cmd method and its implementations.

* Unexport ide_execute_command() and ide_dma_intr().

v2:
* Fix CONFIG_BLK_DEV_IDEDMA=n build (noticed by Randy Dunlap).

* Fix *dma_expiry naming (suggested by Sergei Shtylyov).

There should be no functional changes caused by this patch.

Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 2868041..f5cf04c 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -98,14 +98,16 @@
 		if (handler == NULL)
 			handler = task_no_data_intr;
 		ide_execute_command(drive, tf->command, handler,
-				    WAIT_WORSTCASE, NULL);
+				    WAIT_WORSTCASE);
 		return ide_started;
 	case ATA_PROT_DMA:
 		if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
 		    ide_build_sglist(drive, cmd) == 0 ||
 		    dma_ops->dma_setup(drive, cmd))
 			return ide_stopped;
-		dma_ops->dma_exec_cmd(drive, tf->command);
+		hwif->expiry = dma_ops->dma_timer_expiry;
+		ide_execute_command(drive, tf->command, ide_dma_intr,
+				    2 * WAIT_CMD);
 		dma_ops->dma_start(drive);
 	default:
 		return ide_started;