[PATCH net-next v1 07/11] mlx5: more strict use of page_pool API

Jesper Dangaard Brouer
2019-06-13T18:28:44Z

The mlx5 driver is using page_pool, but not for DMA-mapping (currently), and
is a little too relaxed about returning or releasing page resources, as it
is not strictly necessary, when not using DMA-mappings.

As this patchset is working towards tracking page_pool resources, to know
about in-flight frames on shutdown. Then fix places where mlx5 leak
page_pool resource.

In case of dma_mapping_error, then recycle into page_pool.

In mlx5e_free_rq() moved the page_pool_destroy() call to after the
mlx5e_page_release() calls, as it is more correct.

In mlx5e_page_release() when no recycle was requested, then release page
from the page_pool, via page_pool_release_page().

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: Tariq Toukan <tariqt@mellanox.com>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 9 +++++----
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 3 ++-
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 07de9ca4c53c..2f647be292b6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -625,10 +625,6 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq)
if (rq->xdp_prog)
bpf_prog_put(rq->xdp_prog);

- xdp_rxq_info_unreg(&rq->xdp_rxq);
- if (rq->page_pool)
- page_pool_destroy(rq->page_pool);
-
switch (rq->wq_type) {
case MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ:
kvfree(rq->mpwqe.info);
@@ -645,6 +641,11 @@ static void mlx5e_free_rq(struct mlx5e_rq *rq)

mlx5e_page_release(rq, dma_info, false);
}
+
+ xdp_rxq_info_unreg(&rq->xdp_rxq);
+ if (rq->page_pool)
+ page_pool_destroy(rq->page_pool);
+
mlx5_wq_destroy(&rq->wq_ctrl);
}

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 13133e7f088e..8331ff2ffdc6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -247,7 +247,7 @@ static inline int mlx5e_page_alloc_mapped(struct mlx5e_rq *rq,
dma_info->addr = dma_map_page(rq->pdev, dma_info->page, 0,
PAGE_SIZE, rq->buff.map_dir);
if (unlikely(dma_mapping_error(rq->pdev, dma_info->addr))) {
- put_page(dma_info->page);
+ page_pool_recycle_direct(rq->page_pool, dma_info->page);
dma_info->page = NULL;
return -ENOMEM;
}
@@ -271,6 +271,7 @@ void mlx5e_page_release(struct mlx5e_rq *rq, struct mlx5e_dma_info *dma_info,
page_pool_recycle_direct(rq->page_pool, dma_info->page);
} else {
mlx5e_page_dma_unmap(rq, dma_info);
+ page_pool_release_page(rq->page_pool, dma_info->page);
put_page(dma_info->page);
}
}