[PATCH rdma-next v2 13/15] RDMA/mlx5: Use umem_list for CQ doorbell record

[Jiri Pirko <jiri@resnulli.us>]

From: Jiri Pirko <jiri@nvidia.com>

Load the doorbell record umem from the umem_list, falling back to
ib_umem_get() for the legacy path. Pass the umem_list and a
per-command slot index through the doorbell mapping infrastructure.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 drivers/infiniband/hw/mlx5/cq.c       |  4 ++-
 drivers/infiniband/hw/mlx5/doorbell.c | 41 +++++++++++++++++++++++----
 drivers/infiniband/hw/mlx5/mlx5_ib.h  |  3 +-
 drivers/infiniband/hw/mlx5/qp.c       |  4 +--
 drivers/infiniband/hw/mlx5/srq.c      |  2 +-
 5 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/cq.c b/drivers/infiniband/hw/mlx5/cq.c
index 6118deb5e6dc..ef36417a3c65 100644
--- a/drivers/infiniband/hw/mlx5/cq.c
+++ b/drivers/infiniband/hw/mlx5/cq.c
@@ -759,7 +759,9 @@ static int create_cq_user(struct mlx5_ib_dev *dev, struct ib_udata *udata,
 	if (!page_size)
 		return -EINVAL;
 
-	err = mlx5_ib_db_map_user(context, ucmd.db_addr, &cq->db);
+	err = mlx5_ib_db_map_user(context, ucmd.db_addr,
+				  cq->ibcq.umem_list, UVERBS_BUF_CQ_DBR,
+				  sizeof(__be32) * 2, &cq->db);
 	if (err)
 		return err;
 
diff --git a/drivers/infiniband/hw/mlx5/doorbell.c b/drivers/infiniband/hw/mlx5/doorbell.c
index bd68fcf011f4..a1c5851aba10 100644
--- a/drivers/infiniband/hw/mlx5/doorbell.c
+++ b/drivers/infiniband/hw/mlx5/doorbell.c
@@ -40,25 +40,51 @@
 struct mlx5_ib_user_db_page {
 	struct list_head	list;
 	struct ib_umem	       *umem;
+	struct ib_umem_list     *umem_list;
+	unsigned int		dbr_index;
 	unsigned long		user_virt;
 	int			refcnt;
 	struct mm_struct	*mm;
 };
 
 int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
-			struct mlx5_db *db)
+			struct ib_umem_list *umem_list, unsigned int dbr_index,
+			size_t dbr_size, struct mlx5_db *db)
 {
+	unsigned long dma_offset;
 	struct mlx5_ib_user_db_page *page;
+	struct ib_umem *umem;
 	int err = 0;
 
 	mutex_lock(&context->db_page_mutex);
 
+	umem = ib_umem_list_load(umem_list, dbr_index, dbr_size);
+	if (IS_ERR(umem)) {
+		err = PTR_ERR(umem);
+		goto out;
+	} else if (umem) {
+		/* External umem path - no page sharing */
+		page = kzalloc_obj(*page);
+		if (!page) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		page->umem = umem;
+		page->umem_list = umem_list;
+		page->dbr_index = dbr_index;
+		dma_offset = ib_umem_offset(umem);
+		goto add_page;
+	}
+
+	dma_offset = virt & ~PAGE_MASK;
+
 	list_for_each_entry(page, &context->db_page_list, list)
 		if ((current->mm == page->mm) &&
 		    (page->user_virt == (virt & PAGE_MASK)))
 			goto found;
 
-	page = kmalloc_obj(*page);
+	page = kzalloc_obj(*page);
 	if (!page) {
 		err = -ENOMEM;
 		goto out;
@@ -76,11 +102,11 @@ int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
 	mmgrab(current->mm);
 	page->mm = current->mm;
 
+add_page:
 	list_add(&page->list, &context->db_page_list);
 
 found:
-	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) +
-		  (virt & ~PAGE_MASK);
+	db->dma = sg_dma_address(page->umem->sgt_append.sgt.sgl) + dma_offset;
 	db->u.user_page = page;
 	++page->refcnt;
 
@@ -96,8 +122,11 @@ void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db)
 
 	if (!--db->u.user_page->refcnt) {
 		list_del(&db->u.user_page->list);
-		mmdrop(db->u.user_page->mm);
-		ib_umem_release(db->u.user_page->umem);
+		if (db->u.user_page->mm)
+			mmdrop(db->u.user_page->mm);
+		ib_umem_release_non_listed(db->u.user_page->umem_list,
+					  db->u.user_page->dbr_index,
+					  db->u.user_page->umem);
 		kfree(db->u.user_page);
 	}
 
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 94d1e4f83679..f68f8466e60a 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1261,7 +1261,8 @@ to_mmmap(struct rdma_user_mmap_entry *rdma_entry)
 int mlx5_ib_dev_res_cq_init(struct mlx5_ib_dev *dev);
 int mlx5_ib_dev_res_srq_init(struct mlx5_ib_dev *dev);
 int mlx5_ib_db_map_user(struct mlx5_ib_ucontext *context, unsigned long virt,
-			struct mlx5_db *db);
+			struct ib_umem_list *umem_list, unsigned int dbr_index,
+			size_t dbr_size, struct mlx5_db *db);
 void mlx5_ib_db_unmap_user(struct mlx5_ib_ucontext *context, struct mlx5_db *db);
 void __mlx5_ib_cq_clean(struct mlx5_ib_cq *cq, u32 qpn, struct mlx5_ib_srq *srq);
 void mlx5_ib_cq_clean(struct mlx5_ib_cq *cq, u32 qpn, struct mlx5_ib_srq *srq);
diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index ba5b41fa5ef9..3edfe44f911a 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -918,7 +918,7 @@ static int create_user_rq(struct mlx5_ib_dev *dev, struct ib_pd *pd,
 		ib_umem_num_pages(rwq->umem), page_size, rwq->rq_num_pas,
 		offset);
 
-	err = mlx5_ib_db_map_user(ucontext, ucmd->db_addr, &rwq->db);
+	err = mlx5_ib_db_map_user(ucontext, ucmd->db_addr, NULL, 0, 0, &rwq->db);
 	if (err) {
 		mlx5_ib_dbg(dev, "map failed\n");
 		goto err_umem;
@@ -1062,7 +1062,7 @@ static int _create_user_qp(struct mlx5_ib_dev *dev, struct ib_pd *pd,
 		resp->bfreg_index = MLX5_IB_INVALID_BFREG;
 	qp->bfregn = bfregn;
 
-	err = mlx5_ib_db_map_user(context, ucmd->db_addr, &qp->db);
+	err = mlx5_ib_db_map_user(context, ucmd->db_addr, NULL, 0, 0, &qp->db);
 	if (err) {
 		mlx5_ib_dbg(dev, "map failed\n");
 		goto err_free;
diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c
index 852f6f502d14..d4dbbd5a500f 100644
--- a/drivers/infiniband/hw/mlx5/srq.c
+++ b/drivers/infiniband/hw/mlx5/srq.c
@@ -74,7 +74,7 @@ static int create_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq,
 	}
 	in->umem = srq->umem;
 
-	err = mlx5_ib_db_map_user(ucontext, ucmd.db_addr, &srq->db);
+	err = mlx5_ib_db_map_user(ucontext, ucmd.db_addr, NULL, 0, 0, &srq->db);
 	if (err) {
 		mlx5_ib_dbg(dev, "map doorbell failed\n");
 		goto err_umem;
-- 
2.53.0