diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/bio.h | 2 | ||||
| -rw-r--r-- | include/linux/blk-mq.h | 16 | ||||
| -rw-r--r-- | include/linux/blk_types.h | 12 |
3 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h index 16c1c85613b7..ad2d57908c1c 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -324,6 +324,8 @@ extern struct bio *bio_split(struct bio *bio, int sectors, gfp_t gfp, struct bio_set *bs); int bio_split_io_at(struct bio *bio, const struct queue_limits *lim, unsigned *segs, unsigned max_bytes, unsigned len_align); +u8 bio_seg_gap(struct request_queue *q, struct bio *prev, struct bio *next, + u8 gaps_bit); /** * bio_next_split - get next @sectors from a bio, splitting if necessary diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index b25d12545f46..b54506b3b76d 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -152,6 +152,14 @@ struct request { unsigned short nr_phys_segments; unsigned short nr_integrity_segments; + /* + * The lowest set bit for address gaps between physical segments. This + * provides information necessary for dma optimization opprotunities, + * like for testing if the segments can be coalesced against the + * device's iommu granule. + */ + unsigned char phys_gap_bit; + #ifdef CONFIG_BLK_INLINE_ENCRYPTION struct bio_crypt_ctx *crypt_ctx; struct blk_crypto_keyslot *crypt_keyslot; @@ -208,6 +216,14 @@ struct request { void *end_io_data; }; +/* + * Returns a mask with all bits starting at req->phys_gap_bit set to 1. + */ +static inline unsigned long req_phys_gap_mask(const struct request *req) +{ + return ~(((1 << req->phys_gap_bit) >> 1) - 1); +} + static inline enum req_op req_op(const struct request *req) { return req->cmd_flags & REQ_OP_MASK; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 8e8d1cc8b06c..53501ebb0623 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -218,6 +218,18 @@ struct bio { enum rw_hint bi_write_hint; u8 bi_write_stream; blk_status_t bi_status; + + /* + * The bvec gap bit indicates the lowest set bit in any address offset + * between all bi_io_vecs. This field is initialized only after the bio + * is split to the hardware limits (see bio_split_io_at()). The value + * may be used to consider DMA optimization when performing that + * mapping. The value is compared to a power of two mask where the + * result depends on any bit set within the mask, so saving the lowest + * bit is sufficient to know if any segment gap collides with the mask. + */ + u8 bi_bvec_gap_bit; + atomic_t __bi_remaining; struct bvec_iter bi_iter; |