[PATCH 1/2] mmc: let the dma map ops handle bouncing

[Christoph Hellwig]

Just like we do for all other block drivers.  Especially as the limit
imposed at the moment might be way to pessimistic for iommus.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/mmc/core/queue.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 3557d5c51141..e327f80ebe70 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -350,18 +350,15 @@ static const struct blk_mq_ops mmc_mq_ops = {
 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 {
 	struct mmc_host *host = card->host;
-	u64 limit = BLK_BOUNCE_HIGH;
 	unsigned block_size = 512;
 
-	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
-		limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
-
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, mq->queue);
 	blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 	if (mmc_can_erase(card))
 		mmc_queue_setup_discard(mq->queue, card);
 
-	blk_queue_bounce_limit(mq->queue, limit);
+	if (!mmc_dev(host)->dma_mask || !*mmc_dev(host)->dma_mask)
+		blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
 	blk_queue_max_hw_sectors(mq->queue,
 		min(host->max_blk_count, host->max_req_size / 512));
 	blk_queue_max_segments(mq->queue, host->max_segs);
-- 
2.20.1