While working on the new DMA API I kept getting annoyed how it was placed
right in the middle of the bio splitting code in blk-merge.c.
Split it out into a separate file.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/Makefile | 4 +-
block/blk-merge.c | 133 ---------------------------------------------
block/blk-mq-dma.c | 113 ++++++++++++++++++++++++++++++++++++++
block/blk.h | 21 +++++++
4 files changed, 136 insertions(+), 135 deletions(-)
create mode 100644 block/blk-mq-dma.c
diff --git a/block/Makefile b/block/Makefile
index 36033c0f07bc..c65f4da93702 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -5,8 +5,8 @@
obj-y := bdev.o fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
- blk-merge.o blk-timeout.o \
- blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
+ blk-merge.o blk-timeout.o blk-lib.o blk-mq.o \
+ blk-mq-tag.o blk-mq-dma.o blk-stat.o \
blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \
disk-events.o blk-ia-ranges.o early-lookup.o
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 782308b73b53..3af1d284add5 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -7,7 +7,6 @@
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/blk-integrity.h>
-#include <linux/scatterlist.h>
#include <linux/part_stat.h>
#include <linux/blk-cgroup.h>
@@ -225,27 +224,6 @@ static inline unsigned get_max_io_size(struct bio *bio,
return max_sectors & ~(lbs - 1);
}
-/**
- * get_max_segment_size() - maximum number of bytes to add as a single segment
- * @lim: Request queue limits.
- * @paddr: address of the range to add
- * @len: maximum length available to add at @paddr
- *
- * Returns the maximum number of bytes of the range starting at @paddr that can
- * be added to a single segment.
- */
-static inline unsigned get_max_segment_size(const struct queue_limits *lim,
- phys_addr_t paddr, unsigned int len)
-{
- /*
- * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1
- * after having calculated the minimum.
- */
- return min_t(unsigned long, len,
- min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr),
- (unsigned long)lim->max_segment_size - 1) + 1);
-}
-
/**
* bvec_split_segs - verify whether or not a bvec should be split in the middle
* @lim: [in] queue limits to split based on
@@ -473,117 +451,6 @@ unsigned int blk_recalc_rq_segments(struct request *rq)
return nr_phys_segs;
}
-struct phys_vec {
- phys_addr_t paddr;
- u32 len;
-};
-
-static bool blk_map_iter_next(struct request *req,
- struct req_iterator *iter, struct phys_vec *vec)
-{
- unsigned int max_size;
- struct bio_vec bv;
-
- if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
- if (!iter->bio)
- return false;
- vec->paddr = bvec_phys(&req->special_vec);
- vec->len = req->special_vec.bv_len;
- iter->bio = NULL;
- return true;
- }
-
- if (!iter->iter.bi_size)
- return false;
-
- bv = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
- vec->paddr = bvec_phys(&bv);
- max_size = get_max_segment_size(&req->q->limits, vec->paddr, UINT_MAX);
- bv.bv_len = min(bv.bv_len, max_size);
- bio_advance_iter_single(iter->bio, &iter->iter, bv.bv_len);
-
- /*
- * If we are entirely done with this bi_io_vec entry, check if the next
- * one could be merged into it. This typically happens when moving to
- * the next bio, but some callers also don't pack bvecs tight.
- */
- while (!iter->iter.bi_size || !iter->iter.bi_bvec_done) {
- struct bio_vec next;
-
- if (!iter->iter.bi_size) {
- if (!iter->bio->bi_next)
- break;
- iter->bio = iter->bio->bi_next;
- iter->iter = iter->bio->bi_iter;
- }
-
- next = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
- if (bv.bv_len + next.bv_len > max_size ||
- !biovec_phys_mergeable(req->q, &bv, &next))
- break;
-
- bv.bv_len += next.bv_len;
- bio_advance_iter_single(iter->bio, &iter->iter, next.bv_len);
- }
-
- vec->len = bv.bv_len;
- return true;
-}
-
-static inline struct scatterlist *blk_next_sg(struct scatterlist **sg,
- struct scatterlist *sglist)
-{
- if (!*sg)
- return sglist;
-
- /*
- * If the driver previously mapped a shorter list, we could see a
- * termination bit prematurely unless it fully inits the sg table
- * on each mapping. We KNOW that there must be more entries here
- * or the driver would be buggy, so force clear the termination bit
- * to avoid doing a full sg_init_table() in drivers for each command.
- */
- sg_unmark_end(*sg);
- return sg_next(*sg);
-}
-
-/*
- * Map a request to scatterlist, return number of sg entries setup. Caller
- * must make sure sg can hold rq->nr_phys_segments entries.
- */
-int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist,
- struct scatterlist **last_sg)
-{
- struct req_iterator iter = {
- .bio = rq->bio,
- };
- struct phys_vec vec;
- int nsegs = 0;
-
- /* the internal flush request may not have bio attached */
- if (iter.bio)
- iter.iter = iter.bio->bi_iter;
-
- while (blk_map_iter_next(rq, &iter, &vec)) {
- *last_sg = blk_next_sg(last_sg, sglist);
- sg_set_page(*last_sg, phys_to_page(vec.paddr), vec.len,
- offset_in_page(vec.paddr));
- nsegs++;
- }
-
- if (*last_sg)
- sg_mark_end(*last_sg);
-
- /*
- * Something must have been wrong if the figured number of
- * segment is bigger than number of req's physical segments
- */
- WARN_ON(nsegs > blk_rq_nr_phys_segments(rq));
-
- return nsegs;
-}
-EXPORT_SYMBOL(__blk_rq_map_sg);
-
static inline unsigned int blk_rq_get_max_sectors(struct request *rq,
sector_t offset)
{
diff --git a/block/blk-mq-dma.c b/block/blk-mq-dma.c
new file mode 100644
index 000000000000..5822b8898bdd
--- /dev/null
+++ b/block/blk-mq-dma.c
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "blk.h"
+
+struct phys_vec {
+ phys_addr_t paddr;
+ u32 len;
+};
+
+static bool blk_map_iter_next(struct request *req, struct req_iterator *iter,
+ struct phys_vec *vec)
+{
+ unsigned int max_size;
+ struct bio_vec bv;
+
+ if (req->rq_flags & RQF_SPECIAL_PAYLOAD) {
+ if (!iter->bio)
+ return false;
+ vec->paddr = bvec_phys(&req->special_vec);
+ vec->len = req->special_vec.bv_len;
+ iter->bio = NULL;
+ return true;
+ }
+
+ if (!iter->iter.bi_size)
+ return false;
+
+ bv = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
+ vec->paddr = bvec_phys(&bv);
+ max_size = get_max_segment_size(&req->q->limits, vec->paddr, UINT_MAX);
+ bv.bv_len = min(bv.bv_len, max_size);
+ bio_advance_iter_single(iter->bio, &iter->iter, bv.bv_len);
+
+ /*
+ * If we are entirely done with this bi_io_vec entry, check if the next
+ * one could be merged into it. This typically happens when moving to
+ * the next bio, but some callers also don't pack bvecs tight.
+ */
+ while (!iter->iter.bi_size || !iter->iter.bi_bvec_done) {
+ struct bio_vec next;
+
+ if (!iter->iter.bi_size) {
+ if (!iter->bio->bi_next)
+ break;
+ iter->bio = iter->bio->bi_next;
+ iter->iter = iter->bio->bi_iter;
+ }
+
+ next = mp_bvec_iter_bvec(iter->bio->bi_io_vec, iter->iter);
+ if (bv.bv_len + next.bv_len > max_size ||
+ !biovec_phys_mergeable(req->q, &bv, &next))
+ break;
+
+ bv.bv_len += next.bv_len;
+ bio_advance_iter_single(iter->bio, &iter->iter, next.bv_len);
+ }
+
+ vec->len = bv.bv_len;
+ return true;
+}
+
+static inline struct scatterlist *
+blk_next_sg(struct scatterlist **sg, struct scatterlist *sglist)
+{
+ if (!*sg)
+ return sglist;
+
+ /*
+ * If the driver previously mapped a shorter list, we could see a
+ * termination bit prematurely unless it fully inits the sg table
+ * on each mapping. We KNOW that there must be more entries here
+ * or the driver would be buggy, so force clear the termination bit
+ * to avoid doing a full sg_init_table() in drivers for each command.
+ */
+ sg_unmark_end(*sg);
+ return sg_next(*sg);
+}
+
+/*
+ * Map a request to scatterlist, return number of sg entries setup. Caller
+ * must make sure sg can hold rq->nr_phys_segments entries.
+ */
+int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist,
+ struct scatterlist **last_sg)
+{
+ struct req_iterator iter = {
+ .bio = rq->bio,
+ };
+ struct phys_vec vec;
+ int nsegs = 0;
+
+ /* the internal flush request may not have bio attached */
+ if (iter.bio)
+ iter.iter = iter.bio->bi_iter;
+
+ while (blk_map_iter_next(rq, &iter, &vec)) {
+ *last_sg = blk_next_sg(last_sg, sglist);
+ sg_set_page(*last_sg, phys_to_page(vec.paddr), vec.len,
+ offset_in_page(vec.paddr));
+ nsegs++;
+ }
+
+ if (*last_sg)
+ sg_mark_end(*last_sg);
+
+ /*
+ * Something must have been wrong if the figured number of
+ * segment is bigger than number of req's physical segments
+ */
+ WARN_ON(nsegs > blk_rq_nr_phys_segments(rq));
+
+ return nsegs;
+}
+EXPORT_SYMBOL(__blk_rq_map_sg);
diff --git a/block/blk.h b/block/blk.h
index 665b3d1fb504..d05f7f4ad5b3 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -405,6 +405,27 @@ static inline struct bio *__bio_split_to_limits(struct bio *bio,
}
}
+/**
+ * get_max_segment_size() - maximum number of bytes to add as a single segment
+ * @lim: Request queue limits.
+ * @paddr: address of the range to add
+ * @len: maximum length available to add at @paddr
+ *
+ * Returns the maximum number of bytes of the range starting at @paddr that can
+ * be added to a single segment.
+ */
+static inline unsigned get_max_segment_size(const struct queue_limits *lim,
+ phys_addr_t paddr, unsigned int len)
+{
+ /*
+ * Prevent an overflow if mask = ULONG_MAX and offset = 0 by adding 1
+ * after having calculated the minimum.
+ */
+ return min_t(unsigned long, len,
+ min(lim->seg_boundary_mask - (lim->seg_boundary_mask & paddr),
+ (unsigned long)lim->max_segment_size - 1) + 1);
+}
+
int ll_back_merge_fn(struct request *req, struct bio *bio,
unsigned int nr_segs);
bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
--
2.47.2
