[PATCH] mmc: Use dma_max_pfn(dev) helper for bounce_limitcalculations

From: Santosh Shilimkar
Date: Fri Jul 19 2013 - 21:36:46 EST

DMA bounce limit is the maximum direct DMA'able memory beyond which
bounce buffers has to be used to perform dma operations. MMC queue layer
relies on dma_mask but its calculation is based on max_*pfn which
don't have uniform meaning across architectures. So make use of
dma_max_pfn() which is expected to return the DMAable maximum pfn
value across architectures.

Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Chris Ball <cjb@xxxxxxxxxx>

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
drivers/mmc/card/queue.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index fa9632e..357bbc5 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -15,6 +15,7 @@
#include <linux/freezer.h>
#include <linux/kthread.h>
#include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>

#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -196,7 +197,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];

if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
- limit = *mmc_dev(host)->dma_mask;
+ limit = dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;

mq->card = card;
mq->queue = blk_init_queue(mmc_request_fn, lock);

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