ide: pass command to ide_map_sg()

* Set IDE_TFLAG_WRITE flag and ->rq also for ATA_CMD_PACKET
  commands.

* Pass command to ->dma_setup method and update all its
  implementations accordingly.

* Pass command instead of request to ide_build_sglist(),
  *_build_dmatable() and ide_map_sg().

While at it:

* Fix scc_dma_setup() documentation + use ATA_DMA_WR define.

* Rename sgiioc4_build_dma_table() to sgiioc4_build_dmatable(),
  change return value type to 'int' and drop unused 'ddir'
  argument.

* Do some minor cleanups in [tx4939]ide_dma_setup().

There should be no functional changes caused by this patch.

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/alim15x3.c b/drivers/ide/alim15x3.c
index d3513b6..e837fd9 100644
--- a/drivers/ide/alim15x3.c
+++ b/drivers/ide/alim15x3.c
@@ -191,17 +191,18 @@
 /**
  *	ali15x3_dma_setup	-	begin a DMA phase
  *	@drive:	target device
+ *	@cmd: command
  *
  *	Returns 1 if the DMA cannot be performed, zero on success.
  */
 
-static int ali15x3_dma_setup(ide_drive_t *drive)
+static int ali15x3_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd)
 {
 	if (m5229_revision < 0xC2 && drive->media != ide_disk) {
-		if (rq_data_dir(drive->hwif->rq))
+		if (cmd->tf_flags & IDE_TFLAG_WRITE)
 			return 1;	/* try PIO instead of DMA */
 	}
-	return ide_dma_setup(drive);
+	return ide_dma_setup(drive, cmd);
 }
 
 /**