[PATCH v2 16/26] IB/srp: Convert to new registration API

[Sagi Grimberg <sagig@mellanox.com>]

Instead of constructing a page list, call ib_map_mr_sg
and post a new ib_reg_wr. srp_map_finish_fr now returns
the number of sg elements registered.

Remove srp_finish_mapping since no one is calling it.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 135 +++++++++++++++++-------------------
 drivers/infiniband/ulp/srp/ib_srp.h |  11 ++-
 2 files changed, 71 insertions(+), 75 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 74748d1075fc..8b3cbf9b6f40 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -340,8 +340,6 @@ static void srp_destroy_fr_pool(struct srp_fr_pool *pool)
 		return;
 
 	for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
-		if (d->frpl)
-			ib_free_fast_reg_page_list(d->frpl);
 		if (d->mr)
 			ib_dereg_mr(d->mr);
 	}
@@ -362,7 +360,6 @@ static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
 	struct srp_fr_pool *pool;
 	struct srp_fr_desc *d;
 	struct ib_mr *mr;
-	struct ib_fast_reg_page_list *frpl;
 	int i, ret = -EINVAL;
 
 	if (pool_size <= 0)
@@ -385,12 +382,6 @@ static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
 			goto destroy_pool;
 		}
 		d->mr = mr;
-		frpl = ib_alloc_fast_reg_page_list(device, max_page_list_len);
-		if (IS_ERR(frpl)) {
-			ret = PTR_ERR(frpl);
-			goto destroy_pool;
-		}
-		d->frpl = frpl;
 		list_add_tail(&d->entry, &pool->free_list);
 	}
 
@@ -1320,24 +1311,24 @@ static int srp_map_finish_fr(struct srp_map_state *state,
 	struct srp_target_port *target = ch->target;
 	struct srp_device *dev = target->srp_host->srp_dev;
 	struct ib_send_wr *bad_wr;
-	struct ib_fast_reg_wr wr;
+	struct ib_reg_wr wr;
 	struct srp_fr_desc *desc;
 	u32 rkey;
-	int err;
-
+	int n, err;
 
 	if (WARN_ON_ONCE(state->fr.next >= state->fr.end))
 		return -ENOMEM;
 
 	WARN_ON_ONCE(!dev->use_fast_reg);
 
-	if (state->npages == 0)
+	if (state->sg_nents == 0)
 		return 0;
 
-	if (state->npages == 1 && target->global_mr) {
-		srp_map_desc(state, state->base_dma_addr, state->dma_len,
+	if (state->sg_nents == 1 && target->global_mr) {
+		srp_map_desc(state, sg_dma_address(state->sg),
+			     sg_dma_len(state->sg),
 			     target->global_mr->rkey);
-		return 0;
+		return 1;
 	}
 
 	desc = srp_fr_pool_get(ch->fr_pool);
@@ -1347,46 +1338,33 @@ static int srp_map_finish_fr(struct srp_map_state *state,
 	rkey = ib_inc_rkey(desc->mr->rkey);
 	ib_update_fast_reg_key(desc->mr, rkey);
 
-	memcpy(desc->frpl->page_list, state->pages,
-	       sizeof(state->pages[0]) * state->npages);
+	n = ib_map_mr_sg(desc->mr, state->sg, state->sg_nents,
+			 dev->mr_page_size);
+	if (unlikely(n < 0))
+		return n;
 
-	memset(&wr, 0, sizeof(wr));
-	wr.wr.opcode = IB_WR_FAST_REG_MR;
+	wr.wr.next = NULL;
+	wr.wr.opcode = IB_WR_REG_MR;
 	wr.wr.wr_id = FAST_REG_WR_ID_MASK;
-	wr.iova_start = state->base_dma_addr;
-	wr.page_list = desc->frpl;
-	wr.page_list_len = state->npages;
-	wr.page_shift = ilog2(dev->mr_page_size);
-	wr.length = state->dma_len;
-	wr.access_flags = (IB_ACCESS_LOCAL_WRITE |
-			   IB_ACCESS_REMOTE_READ |
-			   IB_ACCESS_REMOTE_WRITE);
-	wr.rkey = desc->mr->lkey;
+	wr.wr.num_sge = 0;
+	wr.wr.send_flags = 0;
+	wr.mr = desc->mr;
+	wr.key = desc->mr->rkey;
+	wr.access = (IB_ACCESS_LOCAL_WRITE |
+		     IB_ACCESS_REMOTE_READ |
+		     IB_ACCESS_REMOTE_WRITE);
 
 	*state->fr.next++ = desc;
 	state->nmdesc++;
 
-	srp_map_desc(state, state->base_dma_addr, state->dma_len,
-		     desc->mr->rkey);
+	srp_map_desc(state, desc->mr->iova,
+		     desc->mr->length, desc->mr->rkey);
 
 	err = ib_post_send(ch->qp, &wr.wr, &bad_wr);
-	if (err)
+	if (unlikely(err))
 		return err;
 
-	state->npages = 0;
-	state->dma_len = 0;
-
-	return 0;
-}
-
-static int srp_finish_mapping(struct srp_map_state *state,
-			      struct srp_rdma_ch *ch)
-{
-	struct srp_target_port *target = ch->target;
-	struct srp_device *dev = target->srp_host->srp_dev;
-
-	return dev->use_fast_reg ? srp_map_finish_fr(state, ch) :
-				   srp_map_finish_fmr(state, ch);
+	return n;
 }
 
 static int srp_map_sg_entry(struct srp_map_state *state,
@@ -1406,7 +1384,7 @@ static int srp_map_sg_entry(struct srp_map_state *state,
 	while (dma_len) {
 		unsigned offset = dma_addr & ~dev->mr_page_mask;
 		if (state->npages == dev->max_pages_per_mr || offset != 0) {
-			ret = srp_finish_mapping(state, ch);
+			ret = srp_map_finish_fmr(state, ch);
 			if (ret)
 				return ret;
 		}
@@ -1428,7 +1406,7 @@ static int srp_map_sg_entry(struct srp_map_state *state,
 	 */
 	ret = 0;
 	if (len != dev->mr_page_size)
-		ret = srp_finish_mapping(state, ch);
+		ret = srp_map_finish_fmr(state, ch);
 	return ret;
 }
 
@@ -1450,7 +1428,7 @@ static int srp_map_sg_fmr(struct srp_map_state *state, struct srp_rdma_ch *ch,
 			return ret;
 	}
 
-	ret = srp_finish_mapping(state, ch);
+	ret = srp_map_finish_fmr(state, ch);
 	if (ret)
 		return ret;
 
@@ -1463,23 +1441,23 @@ static int srp_map_sg_fr(struct srp_map_state *state, struct srp_rdma_ch *ch,
 			 struct srp_request *req, struct scatterlist *scat,
 			 int count)
 {
-	struct scatterlist *sg;
-	int i, ret;
-
 	state->desc = req->indirect_desc;
-	state->pages = req->map_page;
-	state->fmr.next = req->fmr_list;
-	state->fmr.end = req->fmr_list + ch->target->cmd_sg_cnt;
+	state->fr.next = req->fr_list;
+	state->fr.end = req->fr_list + ch->target->cmd_sg_cnt;
+	state->sg = scat;
+	state->sg_nents = scsi_sg_count(req->scmnd);
 
-	for_each_sg(scat, sg, count, i) {
-		ret = srp_map_sg_entry(state, ch, sg, i);
-		if (ret)
-			return ret;
-	}
+	while (state->sg_nents) {
+		int i, n;
 
-	ret = srp_finish_mapping(state, ch);
-	if (ret)
-		return ret;
+		n = srp_map_finish_fr(state, ch);
+		if (unlikely(n < 0))
+			return n;
+
+		state->sg_nents -= n;
+		for (i = 0; i < n; i++)
+			state->sg = sg_next(state->sg);
+	}
 
 	req->nmdesc = state->nmdesc;
 
@@ -1523,6 +1501,7 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
 	struct srp_map_state state;
 	struct srp_direct_buf idb_desc;
 	u64 idb_pages[1];
+	struct scatterlist idb_sg[1];
 	int ret;
 
 	memset(&state, 0, sizeof(state));
@@ -1530,20 +1509,32 @@ static int srp_map_idb(struct srp_rdma_ch *ch, struct srp_request *req,
 	state.gen.next = next_mr;
 	state.gen.end = end_mr;
 	state.desc = &idb_desc;
-	state.pages = idb_pages;
-	state.pages[0] = (req->indirect_dma_addr &
-			  dev->mr_page_mask);
-	state.npages = 1;
 	state.base_dma_addr = req->indirect_dma_addr;
 	state.dma_len = idb_len;
-	ret = srp_finish_mapping(&state, ch);
-	if (ret < 0)
-		goto out;
+
+	if (dev->use_fast_reg) {
+		state.sg = idb_sg;
+		state.sg_nents = 1;
+		sg_set_buf(idb_sg, req->indirect_desc, idb_len);
+		idb_sg->dma_address = req->indirect_dma_addr; /* hack! */
+		ret = srp_map_finish_fr(&state, ch);
+		if (ret < 0)
+			return ret;
+	} else if (dev->use_fmr) {
+		state.pages = idb_pages;
+		state.pages[0] = (req->indirect_dma_addr &
+				  dev->mr_page_mask);
+		state.npages = 1;
+		ret = srp_map_finish_fmr(&state, ch);
+		if (ret < 0)
+			return ret;
+	} else {
+		return -EINVAL;
+	}
 
 	*idb_rkey = idb_desc.key;
 
-out:
-	return ret;
+	return 0;
 }
 
 static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_rdma_ch *ch,
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index 3608f2e4819c..a31a93716f3f 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -242,7 +242,6 @@ struct srp_iu {
 struct srp_fr_desc {
 	struct list_head		entry;
 	struct ib_mr			*mr;
-	struct ib_fast_reg_page_list	*frpl;
 };
 
 /**
@@ -294,11 +293,17 @@ struct srp_map_state {
 		} gen;
 	};
 	struct srp_direct_buf  *desc;
-	u64		       *pages;
+	union {
+		u64			*pages;
+		struct scatterlist	*sg;
+	};
 	dma_addr_t		base_dma_addr;
 	u32			dma_len;
 	u32			total_len;
-	unsigned int		npages;
+	union {
+		unsigned int		npages;
+		unsigned int		sg_nents;
+	};
 	unsigned int		nmdesc;
 	unsigned int		ndesc;
 };
-- 
1.8.4.3