net/mlx5: Fix QP fragmented buffer allocation

Fix bad alignment of SQ buffer in fragmented QP allocation.
It should start directly after RQ buffer ends.

Take special care of the end case where the RQ buffer does not occupy
a whole page. RQ size is a power of two, so would be the case only for
small RQ sizes (RQ size < PAGE_SIZE).

Fix wrong assignments for sqb->size (mistakenly assigned RQ size),
and for npages value of RQ and SQ.

Fixes: 3a2f70331226 ("net/mlx5: Use order-0 allocations for all WQ types")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

2 files changed, 23 insertions, 13 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/alloc.c b/drivers/net/ethernet/mellanox/mlx5/core/alloc.c
index 323ffe8bf7e4..456f30007ad6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/alloc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/alloc.c
@@ -123,7 +123,7 @@ int mlx5_frag_buf_alloc_node(struct mlx5_core_dev *dev, int size,
 	int i;
 
 	buf->size = size;
-	buf->npages = 1 << get_order(size);
+	buf->npages = DIV_ROUND_UP(size, PAGE_SIZE);
 	buf->page_shift = PAGE_SHIFT;
 	buf->frags = kcalloc(buf->npages, sizeof(struct mlx5_buf_list),
 			     GFP_KERNEL);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/wq.c b/drivers/net/ethernet/mellanox/mlx5/core/wq.c
index b97bb72b4db4..86478a6b99c5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/wq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/wq.c
@@ -113,35 +113,45 @@ err_db_free:
 	return err;
 }
 
-static void mlx5e_qp_set_frag_buf(struct mlx5_frag_buf *buf,
-				  struct mlx5_wq_qp *qp)
+static void mlx5_qp_set_frag_buf(struct mlx5_frag_buf *buf,
+				 struct mlx5_wq_qp *qp)
 {
+	struct mlx5_frag_buf_ctrl *sq_fbc;
 	struct mlx5_frag_buf *rqb, *sqb;
 
-	rqb = &qp->rq.fbc.frag_buf;
+	rqb  = &qp->rq.fbc.frag_buf;
 	*rqb = *buf;
 	rqb->size   = mlx5_wq_cyc_get_byte_size(&qp->rq);
-	rqb->npages = 1 << get_order(rqb->size);
+	rqb->npages = DIV_ROUND_UP(rqb->size, PAGE_SIZE);
 
-	sqb = &qp->sq.fbc.frag_buf;
-	*sqb = *buf;
-	sqb->size   = mlx5_wq_cyc_get_byte_size(&qp->rq);
-	sqb->npages = 1 << get_order(sqb->size);
+	sq_fbc = &qp->sq.fbc;
+	sqb    = &sq_fbc->frag_buf;
+	*sqb   = *buf;
+	sqb->size   = mlx5_wq_cyc_get_byte_size(&qp->sq);
+	sqb->npages = DIV_ROUND_UP(sqb->size, PAGE_SIZE);
 	sqb->frags += rqb->npages; /* first part is for the rq */
+	if (sq_fbc->strides_offset)
+		sqb->frags--;
 }
 
 int mlx5_wq_qp_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		      void *qpc, struct mlx5_wq_qp *wq,
 		      struct mlx5_wq_ctrl *wq_ctrl)
 {
+	u32 sq_strides_offset;
 	int err;
 
 	mlx5_fill_fbc(MLX5_GET(qpc, qpc, log_rq_stride) + 4,
 		      MLX5_GET(qpc, qpc, log_rq_size),
 		      &wq->rq.fbc);
-	mlx5_fill_fbc(ilog2(MLX5_SEND_WQE_BB),
-		      MLX5_GET(qpc, qpc, log_sq_size),
-		      &wq->sq.fbc);
+
+	sq_strides_offset =
+		((wq->rq.fbc.frag_sz_m1 + 1) % PAGE_SIZE) / MLX5_SEND_WQE_BB;
+
+	mlx5_fill_fbc_offset(ilog2(MLX5_SEND_WQE_BB),
+			     MLX5_GET(qpc, qpc, log_sq_size),
+			     sq_strides_offset,
+			     &wq->sq.fbc);
 
 	err = mlx5_db_alloc_node(mdev, &wq_ctrl->db, param->db_numa_node);
 	if (err) {
@@ -156,7 +166,7 @@ int mlx5_wq_qp_create(struct mlx5_core_dev *mdev, struct mlx5_wq_param *param,
 		goto err_db_free;
 	}
 
-	mlx5e_qp_set_frag_buf(&wq_ctrl->buf, wq);
+	mlx5_qp_set_frag_buf(&wq_ctrl->buf, wq);
 
 	wq->rq.db  = &wq_ctrl->db.db[MLX5_RCV_DBR];
 	wq->sq.db  = &wq_ctrl->db.db[MLX5_SND_DBR];