1 files changed, 47 insertions, 1 deletions

diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index b25d12545f46..cae9e857aea4 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;
@@ -999,8 +1015,20 @@ static inline void *blk_mq_rq_to_pdu(struct request *rq)
 	return rq + 1;
 }
 
+static inline struct blk_mq_hw_ctx *queue_hctx(struct request_queue *q, int id)
+{
+	struct blk_mq_hw_ctx *hctx;
+
+	rcu_read_lock();
+	hctx = rcu_dereference(q->queue_hw_ctx)[id];
+	rcu_read_unlock();
+
+	return hctx;
+}
+
 #define queue_for_each_hw_ctx(q, hctx, i)				\
-	xa_for_each(&(q)->hctx_table, (i), (hctx))
+	for ((i) = 0; (i) < (q)->nr_hw_queues &&			\
+	     ({ hctx = queue_hctx((q), i); 1; }); (i)++)
 
 #define hctx_for_each_ctx(hctx, ctx, i)					\
 	for ((i) = 0; (i) < (hctx)->nr_ctx &&				\
@@ -1185,6 +1213,24 @@ static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
 	return max_t(unsigned short, rq->nr_phys_segments, 1);
 }
 
+/**
+ * blk_rq_nr_bvec - return number of bvecs in a request
+ * @rq: request to calculate bvecs for
+ *
+ * Returns the number of bvecs.
+ */
+static inline unsigned int blk_rq_nr_bvec(struct request *rq)
+{
+	struct req_iterator rq_iter;
+	struct bio_vec bv;
+	unsigned int nr_bvec = 0;
+
+	rq_for_each_bvec(bv, rq, rq_iter)
+		nr_bvec++;
+
+	return nr_bvec;
+}
+
 int __blk_rq_map_sg(struct request *rq, struct scatterlist *sglist,
 		struct scatterlist **last_sg);
 static inline int blk_rq_map_sg(struct request *rq, struct scatterlist *sglist)