Premapped buffers don't require a generic bio_vec since these have already been dma mapped. Repurpose the bi_io_vec space to strore dmabuf maps as they are mutually exclusive.
Suggested-by: Keith Busch <[email protected]> Signed-off-by: Pavel Begunkov <[email protected]> --- block/bio.c | 23 ++++++++++++++++++++++- block/blk-merge.c | 15 +++++++++++++++ block/fops.c | 2 ++ include/linux/bio.h | 10 ++++++---- include/linux/blk-mq.h | 7 +++++++ include/linux/blk_types.h | 14 +++++++++++++- include/linux/bvec.h | 3 ++- 7 files changed, 67 insertions(+), 7 deletions(-) diff --git a/block/bio.c b/block/bio.c index 57c127aee116..cc2bb9183c1a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -860,7 +860,12 @@ static int __bio_clone(struct bio *bio, struct bio *bio_src, gfp_t gfp) bio->bi_write_hint = bio_src->bi_write_hint; bio->bi_write_stream = bio_src->bi_write_stream; bio->bi_iter = bio_src->bi_iter; - bio->bi_io_vec = bio_src->bi_io_vec; + + if (op_is_dmabuf(bio->bi_opf)) { + bio->bi_dmabuf_map = bio_src->bi_dmabuf_map; + } else { + bio->bi_io_vec = bio_src->bi_io_vec; + } if (bio->bi_bdev) { if (bio->bi_bdev == bio_src->bi_bdev && @@ -1192,6 +1197,17 @@ void bio_iov_bvec_set(struct bio *bio, const struct iov_iter *iter) bio_set_flag(bio, BIO_CLONED); } +void bio_dmabuf_map_set(struct bio *bio, struct iov_iter *iter) +{ + WARN_ON_ONCE(bio->bi_max_vecs); + + bio->bi_dmabuf_map = iter->dmabuf_map; + bio->bi_vcnt = 0; + bio->bi_iter.bi_offset = iter->iov_offset; + bio->bi_iter.bi_size = iov_iter_count(iter); + bio->bi_opf |= REQ_NOMERGE | REQ_DMABUF; +} + /* * Aligns the bio size to the len_align_mask, releasing excessive bio vecs that * __bio_iov_iter_get_pages may have inserted, and reverts the trimmed length @@ -1254,6 +1270,11 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter, iov_iter_advance(iter, bio->bi_iter.bi_size); return 0; } + if (iov_iter_is_dmabuf_map(iter)) { + bio_dmabuf_map_set(bio, iter); + iov_iter_advance(iter, bio->bi_iter.bi_size); + return 0; + } if (iov_iter_extract_will_pin(iter)) bio_set_flag(bio, BIO_PAGE_PINNED); diff --git a/block/blk-merge.c b/block/blk-merge.c index 258a726071d1..6f0cabfe25ef 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -346,6 +346,20 @@ int bio_split_io_at(struct bio *bio, const struct queue_limits *lim, len_align_mask |= (bc->bc_key->crypto_cfg.data_unit_size - 1); } + if (op_is_dmabuf(bio->bi_opf)) { + /* single contiguous range into the dma-buf */ + nsegs = 1; + + if ((bio->bi_iter.bi_offset & start_align_mask) || + (bio->bi_iter.bi_size & len_align_mask)) + return -EINVAL; + if (bio->bi_iter.bi_size > max_bytes) { + bytes = max_bytes; + goto split; + } + goto out; + } + bio_for_each_bvec(bv, bio, iter) { if (bv.bv_offset & start_align_mask || bv.bv_len & len_align_mask) @@ -376,6 +390,7 @@ int bio_split_io_at(struct bio *bio, const struct queue_limits *lim, bvprvp = &bvprv; } +out: *segs = nsegs; bio->bi_bvec_gap_bit = ffs(gaps); return 0; diff --git a/block/fops.c b/block/fops.c index 15783a6180de..37d491f45015 100644 --- a/block/fops.c +++ b/block/fops.c @@ -348,6 +348,8 @@ static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, * bio_iov_iter_get_pages() and set the bvec directly. */ bio_iov_bvec_set(bio, iter); + } else if (iov_iter_is_dmabuf_map(iter)) { + bio_dmabuf_map_set(bio, iter); } else { ret = blkdev_iov_iter_get_pages(bio, iter, bdev); if (unlikely(ret)) diff --git a/include/linux/bio.h b/include/linux/bio.h index dea9f567379d..c053e9444514 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -80,7 +80,8 @@ static inline bool bio_no_advance_iter(const struct bio *bio) { return bio_op(bio) == REQ_OP_DISCARD || bio_op(bio) == REQ_OP_SECURE_ERASE || - bio_op(bio) == REQ_OP_WRITE_ZEROES; + bio_op(bio) == REQ_OP_WRITE_ZEROES || + op_is_dmabuf(bio->bi_opf); } static inline void *bio_data(struct bio *bio) @@ -399,12 +400,12 @@ static inline void bio_wouldblock_error(struct bio *bio) /* * Calculate number of bvec segments that should be allocated to fit data - * pointed by @iter. If @iter is backed by bvec it's going to be reused - * instead of allocating a new one. + * pointed by @iter. If @iter is backed by a bvec or a dmabuf, the bvec array / + * the dma map are going to be reused, and so no extra allocation is required. */ static inline int bio_iov_vecs_to_alloc(struct iov_iter *iter, int max_segs) { - if (iov_iter_is_bvec(iter)) + if (iov_iter_is_bvec(iter) || iov_iter_is_dmabuf_map(iter)) return 0; return iov_iter_npages(iter, max_segs); } @@ -484,6 +485,7 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter, unsigned len_align_mask); void bio_iov_bvec_set(struct bio *bio, const struct iov_iter *iter); +void bio_dmabuf_map_set(struct bio *bio, struct iov_iter *iter); void __bio_release_pages(struct bio *bio, bool mark_dirty); extern void bio_set_pages_dirty(struct bio *bio); extern void bio_check_pages_dirty(struct bio *bio); diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index af878597afb8..7c7504c84e09 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -1017,6 +1017,13 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq) return rq + 1; } +static inline bool blk_mq_rq_is_dmabuf(struct request *rq) +{ + if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) + return false; + return rq->bio && op_is_dmabuf(rq->bio->bi_opf); +} + static inline struct blk_mq_hw_ctx *queue_hctx(struct request_queue *q, int id) { struct blk_mq_hw_ctx *hctx; diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 8808ee76e73c..d605e31712d4 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -233,7 +233,12 @@ struct bio { atomic_t __bi_remaining; /* The actual vec list, preserved by bio_reset() */ - struct bio_vec *bi_io_vec; + union { + struct bio_vec *bi_io_vec; + /* Driver specific dma map, valid IFF REQ_DMABUF is set */ + struct dma_buf_io_map *bi_dmabuf_map; + }; + struct bvec_iter bi_iter; union { @@ -401,6 +406,7 @@ enum req_flag_bits { __REQ_DRV, /* for driver use */ __REQ_FS_PRIVATE, /* for file system (submitter) use */ __REQ_ATOMIC, /* for atomic write operations */ + __REQ_DMABUF, /* Using premmaped dma buffers */ /* * Command specific flags, keep last: */ @@ -433,6 +439,7 @@ enum req_flag_bits { #define REQ_DRV (__force blk_opf_t)(1ULL << __REQ_DRV) #define REQ_FS_PRIVATE (__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE) #define REQ_ATOMIC (__force blk_opf_t)(1ULL << __REQ_ATOMIC) +#define REQ_DMABUF (__force blk_opf_t)(1ULL << __REQ_DMABUF) #define REQ_NOUNMAP (__force blk_opf_t)(1ULL << __REQ_NOUNMAP) @@ -486,6 +493,11 @@ static inline bool op_is_discard(blk_opf_t op) return (op & REQ_OP_MASK) == REQ_OP_DISCARD; } +static inline bool op_is_dmabuf(blk_opf_t op) +{ + return op & REQ_DMABUF; +} + /* * Check if a bio or request operation is a zone management operation. */ diff --git a/include/linux/bvec.h b/include/linux/bvec.h index fc566ee1c1ff..b63914ff56e3 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -108,7 +108,8 @@ struct bvec_iter { unsigned int bi_idx; /* - * Current offset in the bvec entry pointed to by `bi_idx`. + * Current offset in the bvec entry pointed to by `bi_idx` or into + * a dma-buf map. */ unsigned int bi_offset; } __packed __aligned(4); -- 2.54.0
