[PATCH rdma-next] IB/mlx5: Use fragmented SRQ's buffer for in-kernel users

[Leon Romanovsky <leon@xxxxxxxxxx>]

From: Guy Levi <guyle@xxxxxxxxxxxx>

The current implementation of create SRQ requires contiguous memory, such
requirement is problematic once the memory is fragmented or the system
is low in memory, it causes for failures in dma_zalloc_coherent().

This patch takes the advantage of mlx5_core new API which lets to allocate
a fragmented buffer, and makes the SRQ creation much resilient to memory
fragmentation. Data-path code was adapted to the fact that WQEs can
cross buffers.

Signed-off-by: Guy Levi <guyle@xxxxxxxxxxxx>
Reviewed-by: Majd Dibbiny <majd@xxxxxxxxxxxx>
Reviewed-by: Yishai Hadas <yishaih@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
 drivers/infiniband/hw/mlx5/mlx5_ib.h |  1 +
 drivers/infiniband/hw/mlx5/srq.c     | 14 +++++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 484a080a77ab..37328653dbaa 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -524,6 +524,7 @@ struct mlx5_ib_srq {
 	struct mlx5_core_srq	msrq;
 	struct mlx5_frag_buf	buf;
 	struct mlx5_db		db;
+	struct mlx5_frag_buf_ctrl fbc;
 	u64		       *wrid;
 	/* protect SRQ hanlding
 	 */
diff --git a/drivers/infiniband/hw/mlx5/srq.c b/drivers/infiniband/hw/mlx5/srq.c
index 91dcd3918d96..b3aef0eb39cb 100644
--- a/drivers/infiniband/hw/mlx5/srq.c
+++ b/drivers/infiniband/hw/mlx5/srq.c
@@ -13,7 +13,7 @@
 
 static void *get_wqe(struct mlx5_ib_srq *srq, int n)
 {
-	return mlx5_buf_offset(&srq->buf, n << srq->msrq.wqe_shift);
+	return mlx5_frag_buf_get_wqe(&srq->fbc, n);
 }
 
 static void mlx5_ib_srq_event(struct mlx5_core_srq *srq, enum mlx5_event type)
@@ -142,12 +142,16 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
 		return err;
 	}
 
-	if (mlx5_buf_alloc(dev->mdev, buf_size, &srq->buf)) {
+	if (mlx5_frag_buf_alloc_node(dev->mdev, buf_size, &srq->buf,
+				     dev->mdev->priv.numa_node)) {
 		mlx5_ib_dbg(dev, "buf alloc failed\n");
 		err = -ENOMEM;
 		goto err_db;
 	}
 
+	mlx5_init_fbc(srq->buf.frags, srq->msrq.wqe_shift, ilog2(srq->msrq.max),
+		      &srq->fbc);
+
 	srq->head    = 0;
 	srq->tail    = srq->msrq.max - 1;
 	srq->wqe_ctr = 0;
@@ -164,7 +168,7 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
 		err = -ENOMEM;
 		goto err_buf;
 	}
-	mlx5_fill_page_array(&srq->buf, in->pas);
+	mlx5_fill_page_frag_array(&srq->buf, in->pas);
 
 	srq->wrid = kvmalloc_array(srq->msrq.max, sizeof(u64), GFP_KERNEL);
 	if (!srq->wrid) {
@@ -184,7 +188,7 @@ static int create_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq,
 	kvfree(in->pas);
 
 err_buf:
-	mlx5_buf_free(dev->mdev, &srq->buf);
+	mlx5_frag_buf_free(dev->mdev, &srq->buf);
 
 err_db:
 	mlx5_db_free(dev->mdev, &srq->db);
@@ -201,7 +205,7 @@ static void destroy_srq_user(struct ib_pd *pd, struct mlx5_ib_srq *srq)
 static void destroy_srq_kernel(struct mlx5_ib_dev *dev, struct mlx5_ib_srq *srq)
 {
 	kvfree(srq->wrid);
-	mlx5_buf_free(dev->mdev, &srq->buf);
+	mlx5_frag_buf_free(dev->mdev, &srq->buf);
 	mlx5_db_free(dev->mdev, &srq->db);
 }
 
-- 
2.19.1