[PATCH 1/2] IB/mlx5: Free page from the beginning of the allocation

[Leon Romanovsky <leon@kernel.org>]

From: Danit Goldberg <danitg@mellanox.com>

After the allocation of a page for wqe pointer, the pointer is
shifted. Therefore it is necessary to keep the original address, and
free it at the end.

Fixes: 0f51427bd097 ("RDMA/mlx5: Cleanup WQE page fault handler")
Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 drivers/infiniband/hw/mlx5/odp.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index 0a59912a4cef..416e750808eb 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -1205,7 +1205,7 @@ static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
 {
 	bool sq = pfault->type & MLX5_PFAULT_REQUESTOR;
 	u16 wqe_index = pfault->wqe.wqe_index;
-	void *wqe = NULL, *wqe_end = NULL;
+	void *wqe, *wqe_start = NULL, *wqe_end = NULL;
 	u32 bytes_mapped, total_wqe_bytes;
 	struct mlx5_core_rsc_common *res;
 	int resume_with_error = 1;
@@ -1226,12 +1226,13 @@ static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
 		goto resolve_page_fault;
 	}

-	wqe = (void *)__get_free_page(GFP_KERNEL);
-	if (!wqe) {
+	wqe_start = (void *)__get_free_page(GFP_KERNEL);
+	if (!wqe_start) {
 		mlx5_ib_err(dev, "Error allocating memory for IO page fault handling.\n");
 		goto resolve_page_fault;
 	}

+	wqe = wqe_start;
 	qp = (res->res == MLX5_RES_QP) ? res_to_qp(res) : NULL;
 	if (qp && sq) {
 		ret = mlx5_ib_read_user_wqe_sq(qp, wqe_index, wqe, PAGE_SIZE,
@@ -1286,7 +1287,7 @@ static void mlx5_ib_mr_wqe_pfault_handler(struct mlx5_ib_dev *dev,
 		    pfault->wqe.wq_num, resume_with_error,
 		    pfault->type);
 	mlx5_core_res_put(res);
-	free_page((unsigned long)wqe);
+	free_page((unsigned long)wqe_start);
 }

 static int pages_in_range(u64 address, u32 length)
--
2.20.1