ide: add ide_dma_prepare() helper

* Add ide_dma_prepare() helper.

* Convert ide_issue_pc() and do_rw_taskfile() to use it.

* Make ide_build_sglist() static.

There should be no functional changes caused by this patch.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-atapi.c

@@ -638,7 +638,6 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 {
 	struct ide_atapi_pc *pc;
 	ide_hwif_t *hwif = drive->hwif;
-	const struct ide_dma_ops *dma_ops = hwif->dma_ops;
 	ide_expiry_t *expiry = NULL;
 	struct request *rq = hwif->rq;
 	unsigned int timeout;
@@ -652,12 +651,8 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 		expiry = ide_cd_expiry;
 		timeout = ATAPI_WAIT_PC;
 
-		if (drive->dma) {
-			if (ide_build_sglist(drive, cmd))
-				drive->dma = !dma_ops->dma_setup(drive, cmd);
-			else
-				drive->dma = 0;
-		}
+		if (drive->dma)
+			drive->dma = !ide_dma_prepare(drive, cmd);
 	} else {
 		pc = drive->pc;
 
@@ -675,13 +670,8 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
 			ide_dma_off(drive);
 		}
 
-		if ((pc->flags & PC_FLAG_DMA_OK) &&
-		     (drive->dev_flags & IDE_DFLAG_USING_DMA)) {
-			if (ide_build_sglist(drive, cmd))
-				drive->dma = !dma_ops->dma_setup(drive, cmd);
-			else
-				drive->dma = 0;
-		}
+		if (pc->flags & PC_FLAG_DMA_OK)
+			drive->dma = !ide_dma_prepare(drive, cmd);
 
 		if (!drive->dma)
 			pc->flags &= ~PC_FLAG_DMA_OK;

drivers/ide/ide-dma.c

@@ -128,7 +128,7 @@ int ide_dma_good_drive(ide_drive_t *drive)
  *	operate in a portable fashion.
  */
 
-int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
+static int ide_build_sglist(ide_drive_t *drive, struct ide_cmd *cmd)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	struct scatterlist *sg = hwif->sg_table;
@@ -563,3 +563,12 @@ int ide_allocate_dma_engine(ide_hwif_t *hwif)
 	return 0;
 }
 EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
+
+int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
+{
+	if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
+	    ide_build_sglist(drive, cmd) == 0 ||
+	    drive->hwif->dma_ops->dma_setup(drive, cmd))
+		return 1;
+	return 0;
+}

drivers/ide/ide-taskfile.c

@@ -100,9 +100,7 @@ ide_startstop_t do_rw_taskfile(ide_drive_t *drive, struct ide_cmd *orig_cmd)
 		ide_execute_command(drive, cmd, handler, 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))
+		if (ide_dma_prepare(drive, cmd))
 			return ide_stopped;
 		hwif->expiry = dma_ops->dma_timer_expiry;
 		ide_execute_command(drive, cmd, ide_dma_intr, 2 * WAIT_CMD);

include/linux/ide.h

@@ -1443,7 +1443,8 @@ ide_startstop_t ide_dma_intr(ide_drive_t *);
 int ide_allocate_dma_engine(ide_hwif_t *);
 void ide_release_dma_engine(ide_hwif_t *);
 
-int ide_build_sglist(ide_drive_t *, struct ide_cmd *);
+int ide_dma_prepare(ide_drive_t *, struct ide_cmd *);
+
 void ide_destroy_dmatable(ide_drive_t *);
 
 #ifdef CONFIG_BLK_DEV_IDEDMA_SFF
@@ -1477,8 +1478,8 @@ static inline void ide_check_dma_crc(ide_drive_t *drive) { ; }
 static inline ide_startstop_t ide_dma_intr(ide_drive_t *drive) { return ide_stopped; }
 static inline ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error) { return ide_stopped; }
 static inline void ide_release_dma_engine(ide_hwif_t *hwif) { ; }
-static inline int ide_build_sglist(ide_drive_t *drive,
-				   struct ide_cmd *cmd) { return 0; }
+static inline int ide_dma_prepare(ide_drive_t *drive,
+				  struct ide_cmd *cmd) { return 1; }
 static inline void ide_destroy_dmatable(ide_drive_t *drive) { ; }
 #endif /* CONFIG_BLK_DEV_IDEDMA */