ide: use the dma safe check for REQ_TYPE_ATA_PC

This uses the dma safe check for REQ_TYPE_ATA_PC. The dma safe check
is used for only sg requests but it should be used for other non fs
commands.

This uses blk_queue_update_dma_pad to make the intention clear though
ide don't use the blk APIs so it doesn't change anything.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Borislav Petkov <petkovbb@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-cd.c

@@ -1191,12 +1191,17 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 	info->dma = 0;
 
 	/* sg request */
-	if (rq->bio) {
-		int mask = drive->queue->dma_alignment;
-		unsigned long addr =
-			(unsigned long)page_address(bio_page(rq->bio));
+	if (rq->bio || ((rq->cmd_type == REQ_TYPE_ATA_PC) && rq->data_len)) {
+		struct request_queue *q = drive->queue;
+		unsigned int alignment;
+		unsigned long addr;
 		unsigned long stack_mask = ~(THREAD_SIZE - 1);
 
+		if (rq->bio)
+			addr = (unsigned long)bio_data(rq->bio);
+		else
+			addr = (unsigned long)rq->data;
+
 		info->dma = drive->using_dma;
 
 		/*
@@ -1205,7 +1210,8 @@ static ide_startstop_t cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 		 * NOTE! The "len" and "addr" checks should possibly have
 		 * separate masks.
 		 */
-		if ((rq->data_len & 15) || (addr & mask))
+		alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+		if (addr & alignment || rq->data_len & alignment)
 			info->dma = 0;
 
 		if (!((addr & stack_mask) ^
@@ -1877,6 +1883,7 @@ static int ide_cdrom_setup(ide_drive_t *drive)
 
 	blk_queue_prep_rq(drive->queue, ide_cdrom_prep_fn);
 	blk_queue_dma_alignment(drive->queue, 31);
+	blk_queue_update_dma_pad(drive->queue, 15);
 	drive->queue->unplug_delay = (1 * HZ) / 1000;
 	if (!drive->queue->unplug_delay)
 		drive->queue->unplug_delay = 1;