# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.815   -> 1.816  
#	drivers/block/ll_rw_blk.c	1.125   -> 1.126  
#	include/linux/blkdev.h	1.78    -> 1.79   
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/10/28	axboe@burns.home.kernel.dk	1.816
# Make it possible for a device to specify the dma alignment restrictions
# it has. This will be used by future infrastructure when mapping
# in user pages, and allows us to dma to on ATAPI even though user address
# and length is not sector size aligned.
# --------------------------------------------
#
diff -Nru a/drivers/block/ll_rw_blk.c b/drivers/block/ll_rw_blk.c
--- a/drivers/block/ll_rw_blk.c	Mon Oct 28 18:07:44 2002
+++ b/drivers/block/ll_rw_blk.c	Mon Oct 28 18:07:44 2002
@@ -242,6 +242,7 @@
 	q->backing_dev_info.state = 0;
 	blk_queue_max_sectors(q, MAX_SECTORS);
 	blk_queue_hardsect_size(q, 512);
+	blk_queue_dma_alignment(q, 511);
 
 	/*
 	 * by default assume old behaviour and bounce for any highmem page
@@ -408,6 +409,21 @@
 	q->seg_boundary_mask = mask;
 }
 
+/**
+ * blk_queue_dma_alignment - set dma length and memory alignment
+ * @q:  the request queue for the device
+ * @dma_mask:  alignment mask
+ *
+ * description:
+ *    set required memory and length aligment for direct dma transactions.
+ *    this is used when buiding direct io requests for the queue.
+ *
+ **/
+void blk_queue_dma_alignment(request_queue_t *q, int mask)
+{
+	q->dma_alignment = mask;
+}
+
 void blk_queue_assign_lock(request_queue_t *q, spinlock_t *lock)
 {
 	spin_lock_init(lock);
@@ -2124,6 +2140,7 @@
 EXPORT_SYMBOL(blk_queue_max_segment_size);
 EXPORT_SYMBOL(blk_queue_hardsect_size);
 EXPORT_SYMBOL(blk_queue_segment_boundary);
+EXPORT_SYMBOL(blk_queue_dma_alignment);
 EXPORT_SYMBOL(blk_rq_map_sg);
 EXPORT_SYMBOL(blk_nohighio);
 EXPORT_SYMBOL(blk_dump_rq_flags);
diff -Nru a/include/linux/blkdev.h b/include/linux/blkdev.h
--- a/include/linux/blkdev.h	Mon Oct 28 18:07:44 2002
+++ b/include/linux/blkdev.h	Mon Oct 28 18:07:44 2002
@@ -215,6 +215,7 @@
 	unsigned int		max_segment_size;
 
 	unsigned long		seg_boundary_mask;
+	unsigned int		dma_alignment;
 
 	wait_queue_head_t	queue_wait;
 
@@ -346,6 +347,7 @@
 extern void blk_queue_assign_lock(request_queue_t *, spinlock_t *);
 extern void blk_queue_prep_rq(request_queue_t *, prep_rq_fn *pfn);
 extern void blk_queue_merge_bvec(request_queue_t *, merge_bvec_fn *);
+extern void blk_queue_dma_alignment(request_queue_t *, int);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 
 extern int blk_rq_map_sg(request_queue_t *, struct request *, struct scatterlist *);
@@ -390,6 +392,21 @@
 static inline int bdev_hardsect_size(struct block_device *bdev)
 {
 	return queue_hardsect_size(bdev_get_queue(bdev));
+}
+
+static inline int queue_dma_alignment(request_queue_t *q)
+{
+	int retval = 511;
+
+	if (q && q->dma_alignment)
+		retval = q->dma_alignment;
+
+	return retval;
+}
+
+static inline int bdev_dma_aligment(struct block_device *bdev)
+{
+	return queue_dma_alignment(bdev_get_queue(bdev));
 }
 
 #define blk_finished_io(nsects)	do { } while (0)