net/mlx5e: Non-atomic RQ state indicator for UMR WQE in progress

The indication for a UMR WQE in progress is needed only within
the NAPI context, and hence no races possible and no need for
the use of atomic operations.
The only place the flag is read outside of NAPI context is
in closure flow, after RQ is disabled flag is no more accessed
in NAPI.
Use a boolean instead of a bit in ring state, so that its
non-atomic set operations do not race with the atomic sets of
the other bits.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 0c4f1f30085aa845718f150d0e33187e07074869..bce2080eb86a1c07da557ca494e5d9cf2d9c6573 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -291,7 +291,6 @@ struct mlx5e_tstamp {
 
 enum {
        MLX5E_RQ_STATE_ENABLED,
-       MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS,
        MLX5E_RQ_STATE_AM,
 };
 
@@ -539,6 +538,7 @@ struct mlx5e_rq {
                        void                  *mtt_no_align;
                        u16                    num_strides;
                        u8                     log_stride_sz;
+                       bool                   umr_in_progress;
                } mpwqe;
        };
        struct {

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 411fb68794bcd60572657fcb9cf35e73301a7510..2767a3ee81bc45ee7ff989ba284bd592fad82195 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -886,7 +886,8 @@ static void mlx5e_free_rx_descs(struct mlx5e_rq *rq)
        u16 wqe_ix;
 
        /* UMR WQE (if in progress) is always at wq->head */
-       if (test_bit(MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS, &rq->state))
+       if (rq->wq_type == MLX5_WQ_TYPE_LINKED_LIST_STRIDING_RQ &&
+           rq->mpwqe.umr_in_progress)
                mlx5e_free_rx_mpwqe(rq, &rq->mpwqe.info[wq->head]);
 
        while (!mlx5_wq_ll_is_empty(wq)) {

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index a5522c3992a25e500be8e1802d5da5384b2b84bc..11dba994002903c3d9194ad88c6e2ef8f37dd2c3 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -422,7 +422,7 @@ void mlx5e_post_rx_mpwqe(struct mlx5e_rq *rq)
        struct mlx5_wq_ll *wq = &rq->wq;
        struct mlx5e_rx_wqe *wqe = mlx5_wq_ll_get_wqe(wq, wq->head);
 
-       clear_bit(MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS, &rq->state);
+       rq->mpwqe.umr_in_progress = false;
 
        if (unlikely(!MLX5E_TEST_BIT(rq->state, MLX5E_RQ_STATE_ENABLED))) {
                mlx5e_free_rx_mpwqe(rq, &rq->mpwqe.info[wq->head]);
@@ -441,10 +441,13 @@ int mlx5e_alloc_rx_mpwqe(struct mlx5e_rq *rq, struct mlx5e_rx_wqe *wqe, u16 ix)
 {
        int err;
 
+       if (rq->mpwqe.umr_in_progress)
+               return -EBUSY;
+
        err = mlx5e_alloc_rx_umr_mpwqe(rq, ix);
        if (unlikely(err))
                return err;
-       set_bit(MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS, &rq->state);
+       rq->mpwqe.umr_in_progress = true;
        mlx5e_post_umr_wqe(rq, ix);
        return -EBUSY;
 }
@@ -467,9 +470,6 @@ bool mlx5e_post_rx_wqes(struct mlx5e_rq *rq)
        if (mlx5_wq_ll_is_full(wq))
                return false;
 
-       if (test_bit(MLX5E_RQ_STATE_UMR_WQE_IN_PROGRESS, &rq->state))
-               return true;
-
        do {
                struct mlx5e_rx_wqe *wqe = mlx5_wq_ll_get_wqe(wq, wq->head);