X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=block%2Fblk-map.c;h=0b1af5a3537ca0728407c8acfedfaba44338cd19;hb=3a57a788757738b8f80a82d4f5101fefb8fd7a58;hp=c07d9c8317f4c055d3821302c22df20cf2627195;hpb=9446389ef612096704fdf18fa79bab423d4110f0;p=pandora-kernel.git

diff --git a/block/blk-map.c b/block/blk-map.c
index c07d9c8317f4..0b1af5a3537c 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -5,6 +5,7 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <scsi/sg.h>		/* for struct sg_iovec */
 
 #include "blk.h"
 
@@ -140,25 +141,8 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
 		ubuf += ret;
 	}
 
-	/*
-	 * __blk_rq_map_user() copies the buffers if starting address
-	 * or length isn't aligned to dma_pad_mask.  As the copied
-	 * buffer is always page aligned, we know that there's enough
-	 * room for padding.  Extend the last bio and update
-	 * rq->data_len accordingly.
-	 *
-	 * On unmap, bio_uncopy_user() will use unmodified
-	 * bio_map_data pointed to by bio->bi_private.
-	 */
-	if (len & q->dma_pad_mask) {
-		unsigned int pad_len = (q->dma_pad_mask & ~len) + 1;
-		struct bio *tail = rq->biotail;
-
-		tail->bi_io_vec[tail->bi_vcnt - 1].bv_len += pad_len;
-		tail->bi_size += pad_len;
-
-		rq->extra_len += pad_len;
-	}
+	if (!bio_flagged(bio, BIO_USER_MAPPED))
+		rq->cmd_flags |= REQ_COPY_USER;
 
 	rq->buffer = rq->data = NULL;
 	return 0;
@@ -194,15 +178,26 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 			struct sg_iovec *iov, int iov_count, unsigned int len)
 {
 	struct bio *bio;
+	int i, read = rq_data_dir(rq) == READ;
+	int unaligned = 0;
 
 	if (!iov || iov_count <= 0)
 		return -EINVAL;
 
-	/* we don't allow misaligned data like bio_map_user() does.  If the
-	 * user is using sg, they're expected to know the alignment constraints
-	 * and respect them accordingly */
-	bio = bio_map_user_iov(q, NULL, iov, iov_count,
-				rq_data_dir(rq) == READ);
+	for (i = 0; i < iov_count; i++) {
+		unsigned long uaddr = (unsigned long)iov[i].iov_base;
+
+		if (uaddr & queue_dma_alignment(q)) {
+			unaligned = 1;
+			break;
+		}
+	}
+
+	if (unaligned || (q->dma_pad_mask & len))
+		bio = bio_copy_user_iov(q, iov, iov_count, read);
+	else
+		bio = bio_map_user_iov(q, NULL, iov, iov_count, read);
+
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
 
@@ -212,6 +207,9 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 		return -EINVAL;
 	}
 
+	if (!bio_flagged(bio, BIO_USER_MAPPED))
+		rq->cmd_flags |= REQ_COPY_USER;
+
 	bio_get(bio);
 	blk_rq_bio_prep(q, rq, bio);
 	rq->buffer = rq->data = NULL;
@@ -257,10 +255,18 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
  * @kbuf:	the kernel buffer
  * @len:	length of user data
  * @gfp_mask:	memory allocation flags
+ *
+ * Description:
+ *    Data will be mapped directly if possible. Otherwise a bounce
+ *    buffer is used.
  */
 int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 		    unsigned int len, gfp_t gfp_mask)
 {
+	unsigned long kaddr;
+	unsigned int alignment;
+	int reading = rq_data_dir(rq) == READ;
+	int do_copy = 0;
 	struct bio *bio;
 
 	if (len > (q->max_hw_sectors << 9))
@@ -268,13 +274,24 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (!len || !kbuf)
 		return -EINVAL;
 
-	bio = bio_map_kern(q, kbuf, len, gfp_mask);
+	kaddr = (unsigned long)kbuf;
+	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+	do_copy = ((kaddr & alignment) || (len & alignment));
+
+	if (do_copy)
+		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
+	else
+		bio = bio_map_kern(q, kbuf, len, gfp_mask);
+
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
 
 	if (rq_data_dir(rq) == WRITE)
 		bio->bi_rw |= (1 << BIO_RW);
 
+	if (do_copy)
+		rq->cmd_flags |= REQ_COPY_USER;
+
 	blk_rq_bio_prep(q, rq, bio);
 	blk_queue_bounce(q, &rq->bio);
 	rq->buffer = rq->data = NULL;