1 files changed, 19 insertions, 3 deletions

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 9a8ffdd0ce3d..1344a0ea5cc6 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -140,7 +140,7 @@ void blk_queue_bounce_limit(struct request_queue *q, u64 dma_addr)
         /* Assume anything <= 4GB can be handled by IOMMU.
            Actually some IOMMUs can handle everything, but I don't
            know of a way to test this here. */
-        if (b_pfn < (min_t(u64, 0xffffffff, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
+        if (b_pfn <= (min_t(u64, 0xffffffff, BLK_BOUNCE_HIGH) >> PAGE_SHIFT))
                 dma = 1;
         q->bounce_pfn = max_low_pfn;
 #else
@@ -293,8 +293,24 @@ void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b)
 EXPORT_SYMBOL(blk_queue_stack_limits);
 
 /**
- * blk_queue_dma_drain - Set up a drain buffer for excess dma.
+ * blk_queue_dma_pad - set pad mask
+ * @q:     the request queue for the device
+ * @mask:  pad mask
+ *
+ * Set pad mask.  Direct IO requests are padded to the mask specified.
  *
+ * Appending pad buffer to a request modifies ->data_len such that it
+ * includes the pad buffer.  The original requested data length can be
+ * obtained using blk_rq_raw_data_len().
+ **/
+void blk_queue_dma_pad(struct request_queue *q, unsigned int mask)
+{
+        q->dma_pad_mask = mask;
+}
+EXPORT_SYMBOL(blk_queue_dma_pad);
+
+/**
+ * blk_queue_dma_drain - Set up a drain buffer for excess dma.
  * @q:  the request queue for the device
  * @dma_drain_needed: fn which returns non-zero if drain is necessary
  * @buf:        physically contiguous buffer
@@ -316,7 +332,7 @@ EXPORT_SYMBOL(blk_queue_stack_limits);
  * device can support otherwise there won't be room for the drain
  * buffer.
  */
-extern int blk_queue_dma_drain(struct request_queue *q,
+int blk_queue_dma_drain(struct request_queue *q,
                                dma_drain_needed_fn *dma_drain_needed,
                                void *buf, unsigned int size)
 {