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/ide-dma-sff.c b/drivers/ide/ide-dma-sff.c
index 7bf28a9..b7eb810 100644
--- a/drivers/ide/ide-dma-sff.c
+++ b/drivers/ide/ide-dma-sff.c
@@ -111,7 +111,7 @@
  *	May also be invoked from trm290.c
  */
 
-int ide_build_dmatable(ide_drive_t *drive, struct request *rq)
+int ide_build_dmatable(ide_drive_t *drive, struct ide_cmd *cmd)
 {
 	ide_hwif_t *hwif = drive->hwif;
 	__le32 *table = (__le32 *)hwif->dmatable_cpu;
@@ -120,7 +120,7 @@
 	struct scatterlist *sg;
 	u8 is_trm290 = !!(hwif->host_flags & IDE_HFLAG_TRM290);
 
-	for_each_sg(hwif->sg_table, sg, hwif->cmd.sg_nents, i) {
+	for_each_sg(hwif->sg_table, sg, cmd->sg_nents, i) {
 		u32 cur_addr, cur_len, xcount, bcount;
 
 		cur_addr = sg_dma_address(sg);
@@ -175,6 +175,7 @@
 /**
  *	ide_dma_setup	-	begin a DMA phase
  *	@drive: target device
+ *	@cmd: command
  *
  *	Build an IDE DMA PRD (IDE speak for scatter gather table)
  *	and then set up the DMA transfer registers for a device
@@ -185,17 +186,16 @@
  *	is returned.
  */
 
-int ide_dma_setup(ide_drive_t *drive)
+int ide_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd)
 {
 	ide_hwif_t *hwif = drive->hwif;
-	struct request *rq = hwif->rq;
-	unsigned int reading = rq_data_dir(rq) ? 0 : ATA_DMA_WR;
 	u8 mmio = (hwif->host_flags & IDE_HFLAG_MMIO) ? 1 : 0;
+	u8 rw = (cmd->tf_flags & IDE_TFLAG_WRITE) ? 0 : ATA_DMA_WR;
 	u8 dma_stat;
 
 	/* fall back to pio! */
-	if (!ide_build_dmatable(drive, rq)) {
-		ide_map_sg(drive, rq);
+	if (ide_build_dmatable(drive, cmd) == 0) {
+		ide_map_sg(drive, cmd);
 		return 1;
 	}
 
@@ -208,9 +208,9 @@
 
 	/* specify r/w */
 	if (mmio)
-		writeb(reading, (void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
+		writeb(rw, (void __iomem *)(hwif->dma_base + ATA_DMA_CMD));
 	else
-		outb(reading, hwif->dma_base + ATA_DMA_CMD);
+		outb(rw, hwif->dma_base + ATA_DMA_CMD);
 
 	/* read DMA status for INTR & ERROR flags */
 	dma_stat = hwif->dma_ops->dma_sff_read_status(hwif);