From 22541ab8e644e7ca437eb4c8371b9171a9c1c906 Mon Sep 17 00:00:00 2001
From: James Bottomley <James.Bottomley@HansenPartnership.com>
Date: Mon, 31 Dec 2007 16:37:00 -0600
Subject: [PATCH] --- yaml --- r: 77093 b: refs/heads/master c:
 11c3e689f1c3a73e3af7b0ea767b1b0626da8033 h: refs/heads/master i:   77091:
 6822d3fcd0897c3cd614a5be7381dbddd151e347 v: v3

---
 [refs]                       |  2 +-
 trunk/block/ll_rw_blk.c      | 24 ++++++++++++++++++++++++
 trunk/include/linux/blkdev.h |  1 +
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 9c5261502f7f..73bd1dc78cb1 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 166a72878f76e911f2d1ce4b2310d4403e94be11
+refs/heads/master: 11c3e689f1c3a73e3af7b0ea767b1b0626da8033
diff --git a/trunk/block/ll_rw_blk.c b/trunk/block/ll_rw_blk.c
index 8b919940b2ab..14af36c5cdb2 100644
--- a/trunk/block/ll_rw_blk.c
+++ b/trunk/block/ll_rw_blk.c
@@ -759,6 +759,30 @@ void blk_queue_dma_alignment(struct request_queue *q, int mask)
 
 EXPORT_SYMBOL(blk_queue_dma_alignment);
 
+/**
+ * blk_queue_update_dma_alignment - update dma length and memory alignment
+ * @q:     the request queue for the device
+ * @mask:  alignment mask
+ *
+ * description:
+ *    update required memory and length aligment for direct dma transactions.
+ *    If the requested alignment is larger than the current alignment, then
+ *    the current queue alignment is updated to the new value, otherwise it
+ *    is left alone.  The design of this is to allow multiple objects
+ *    (driver, device, transport etc) to set their respective
+ *    alignments without having them interfere.
+ *
+ **/
+void blk_queue_update_dma_alignment(struct request_queue *q, int mask)
+{
+	BUG_ON(mask > PAGE_SIZE);
+
+	if (mask > q->dma_alignment)
+		q->dma_alignment = mask;
+}
+
+EXPORT_SYMBOL(blk_queue_update_dma_alignment);
+
 /**
  * blk_queue_find_tag - find a request by its tag and queue
  * @q:	 The request queue for the device
diff --git a/trunk/include/linux/blkdev.h b/trunk/include/linux/blkdev.h
index d18ee67b40f8..81e99e516302 100644
--- a/trunk/include/linux/blkdev.h
+++ b/trunk/include/linux/blkdev.h
@@ -766,6 +766,7 @@ extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 extern void blk_queue_dma_alignment(struct request_queue *, int);
+extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);