[RFC PATCH 08/28] block: Introduce dmavec_phys_mergeable()

Logan Gunthorpe
2019-06-20T16:12:20Z

Introduce a new helper which is an analog of biovec_phys_mergeable()
for dma-direct vectors.

This also provides a common helper vec_phys_mergeable() for use in
code that's general to both bio_vecs and dma_vecs.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
block/blk.h | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/block/blk.h b/block/blk.h
index 7814aa207153..4142383eed7a 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -66,20 +66,36 @@ static inline void blk_queue_enter_live(struct request_queue *q)
percpu_ref_get(&q->q_usage_counter);
}

+static inline bool vec_phys_mergeable(struct request_queue *q,
+ unsigned long addr1, unsigned int len1,
+ unsigned long addr2, unsigned int len2)
+{
+ unsigned long mask = queue_segment_boundary(q);
+
+ if (addr1 + len1 != addr2)
+ return false;
+ if ((addr1 | mask) != ((addr2 + len2 - 1) | mask))
+ return false;
+ return true;
+}
+
static inline bool biovec_phys_mergeable(struct request_queue *q,
struct bio_vec *vec1, struct bio_vec *vec2)
{
- unsigned long mask = queue_segment_boundary(q);
phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;

- if (addr1 + vec1->bv_len != addr2)
- return false;
if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
return false;
- if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
- return false;
- return true;
+
+ return vec_phys_mergeable(q, addr1, vec1->bv_len, addr2, vec2->bv_len);
+}
+
+static inline bool dmavec_phys_mergeable(struct request_queue *q,
+ struct dma_vec *vec1, struct dma_vec *vec2)
+{
+ return vec_phys_mergeable(q, vec1->dv_addr, vec1->dv_len,
+ vec2->dv_addr, vec2->dv_len);
}

static inline bool __bvec_gap_to_prev(struct request_queue *q,
--
2.20.1