block: separate out padding from alignment

[linux-2.6-omap-h63xx.git] / include / linux / blkdev.h

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index cf170391c47471579b56477940ea86ec364e9cf4..6f79d40dd3c01f25c105b9bdae4f5e70a7c88e1e 100644 (file)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -39,7 +39,6 @@ void exit_io_context(void);
 struct io_context *get_io_context(gfp_t gfp_flags, int node);
 struct io_context *alloc_io_context(gfp_t gfp_flags, int node);
 void copy_io_context(struct io_context **pdst, struct io_context **psrc);
-void swap_io_context(struct io_context **ioc1, struct io_context **ioc2);
 
 struct request;
 typedef void (rq_end_io_fn)(struct request *, int);
@@ -138,7 +137,9 @@ enum rq_flag_bits {
 #define BLK_MAX_CDB    16
 
 /*
- * try to put the fields that are referenced together in the same cacheline
+ * try to put the fields that are referenced together in the same cacheline.
+ * if you modify this structure, be sure to check block/blk-core.c:rq_init()
+ * as well!
  */
 struct request {
        struct list_head queuelist;
@@ -216,6 +217,7 @@ struct request {
        unsigned char cmd[BLK_MAX_CDB];
 
        unsigned int data_len;
+       unsigned int extra_len; /* length of alignment and padding */
        unsigned int sense_len;
        void *data;
        void *sense;
@@ -257,6 +259,7 @@ struct bio_vec;
 typedef int (merge_bvec_fn) (struct request_queue *, struct bio *, struct bio_vec *);
 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
 typedef void (softirq_done_fn)(struct request *);
+typedef int (dma_drain_needed_fn)(struct request *);
 
 enum blk_queue_state {
        Queue_down,
@@ -293,6 +296,7 @@ struct request_queue
        merge_bvec_fn           *merge_bvec_fn;
        prepare_flush_fn        *prepare_flush_fn;
        softirq_done_fn         *softirq_done_fn;
+       dma_drain_needed_fn     *dma_drain_needed;
 
        /*
         * Dispatch queue sorting
@@ -358,6 +362,7 @@ struct request_queue
        unsigned long           seg_boundary_mask;
        void                    *dma_drain_buffer;
        unsigned int            dma_drain_size;
+       unsigned int            dma_pad_mask;
        unsigned int            dma_alignment;
 
        struct blk_queue_tag    *queue_tags;
@@ -697,8 +702,10 @@ extern void blk_queue_max_hw_segments(struct request_queue *, unsigned short);
 extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
 extern void blk_queue_hardsect_size(struct request_queue *, unsigned short);
 extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
-extern int blk_queue_dma_drain(struct request_queue *q, void *buf,
-                              unsigned int size);
+extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
+extern int blk_queue_dma_drain(struct request_queue *q,
+                              dma_drain_needed_fn *dma_drain_needed,
+                              void *buf, unsigned int size);
 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 *);