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From: Saeed Mahameed <saeed@kernel•org>
To: "David S. Miller" <davem@davemloft•net>,
	Jakub Kicinski <kuba@kernel•org>, Paolo Abeni <pabeni@redhat•com>,
	Eric Dumazet <edumazet@google•com>
Cc: Saeed Mahameed <saeedm@nvidia•com>,
	netdev@vger•kernel.org, Tariq Toukan <tariqt@nvidia•com>,
	Maxim Mikityanskiy <maximmi@nvidia•com>
Subject: [PATCH net-next 02/16] net/mlx5e: xsk: Drop the check for XSK state in mlx5e_xsk_wakeup
Date: Fri, 30 Sep 2022 09:28:49 -0700	[thread overview]
Message-ID: <20220930162903.62262-3-saeed@kernel.org> (raw)
In-Reply-To: <20220930162903.62262-1-saeed@kernel.org>

From: Maxim Mikityanskiy <maximmi@nvidia•com>

The MLX5E_CHANNEL_STATE_XSK flag checked in mlx5e_xsk_wakeup indicates
that XSK queues are open, but not necessarily activated. This check is
not very useful, because:

0. Both XSK setup and netdev state transitions take the same state_lock
mutex, so they can't happen at the same time.

1. If the netdev is up, xsk_is_bound can return true only when
MLX5E_CHANNEL_STATE_XSK is set on the corresponding channel.
mlx5e_xsk_wakeup is only called when xsk_is_bound is true.

2. If the XSK socket is bound, and the netdev is going up or down,
mlx5e_xsk_wakeup can take one of two branches, depending on the return
value of napi_if_scheduled_mark_missed:

2.1. True means one of two things: either NAPI was enabled at this
point, which means MLX5E_CHANNEL_STATE_XSK was also set; or NAPI was
disabled, and nothing really happened.

2.2. False means that NAPI was enabled by this point, which also implies
MLX5E_CHANNEL_STATE_XSK was set. Additionally, mlx5e_xsk_wakeup contains
a following check for MLX5E_SQ_STATE_ENABLED on async_icosq, and this
flag implies MLX5E_CHANNEL_STATE_XSK too on XSK channels.

As checking this flag doesn't cut any flows, remove the check.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia•com>
Reviewed-by: Tariq Toukan <tariqt@nvidia•com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia•com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c | 2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c    | 3 ---
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
index 5129b9bf534f..d7dfc7d2c058 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
@@ -154,7 +154,7 @@ int mlx5e_open_xsk(struct mlx5e_priv *priv, struct mlx5e_params *params,
 void mlx5e_close_xsk(struct mlx5e_channel *c)
 {
 	clear_bit(MLX5E_CHANNEL_STATE_XSK, c->state);
-	synchronize_net(); /* Sync with the XSK wakeup and with NAPI. */
+	synchronize_net(); /* Sync with NAPI. */
 
 	mlx5e_close_rq(&c->xskrq);
 	mlx5e_close_cq(&c->xskrq.cq);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c
index 1203d7d5f9bd..c856fc3f197e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/tx.c
@@ -22,9 +22,6 @@ int mlx5e_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
 
 	c = priv->channels.c[ix];
 
-	if (unlikely(!test_bit(MLX5E_CHANNEL_STATE_XSK, c->state)))
-		return -EINVAL;
-
 	if (!napi_if_scheduled_mark_missed(&c->napi)) {
 		/* To avoid WQE overrun, don't post a NOP if async_icosq is not
 		 * active and not polled by NAPI. Return 0, because the upcoming
-- 
2.37.3


  parent reply	other threads:[~2022-09-30 16:29 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-30 16:28 [PATCH net-next 00/16] mlx5 xsk updates part3 2022-09-30 Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 01/16] net/mlx5e: xsk: Use mlx5e_trigger_napi_icosq for XSK wakeup Saeed Mahameed
2022-09-30 16:28 ` Saeed Mahameed [this message]
2022-09-30 16:28 ` [PATCH net-next 03/16] net/mlx5e: Introduce wqe_index_mask for legacy RQ Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 04/16] net/mlx5e: Make the wqe_index_mask calculation more exact Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 05/16] net/mlx5e: Use partial batches in legacy RQ Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 06/16] net/mlx5e: xsk: Use partial batches in legacy RQ with XSK Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 07/16] net/mlx5e: Remove the outer loop when allocating legacy RQ WQEs Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 08/16] net/mlx5e: xsk: Split out WQE allocation for legacy XSK RQ Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 09/16] net/mlx5e: xsk: Use xsk_buff_alloc_batch on legacy RQ Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 10/16] net/mlx5e: xsk: Use xsk_buff_alloc_batch on striding RQ Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 11/16] net/mlx5e: Use non-XSK page allocator in SHAMPO Saeed Mahameed
2022-09-30 16:28 ` [PATCH net-next 12/16] net/mlx5e: Call mlx5e_page_release_dynamic directly where possible Saeed Mahameed
2022-09-30 16:29 ` [PATCH net-next 13/16] net/mlx5e: Optimize RQ page deallocation Saeed Mahameed
2022-09-30 16:29 ` [PATCH net-next 14/16] net/mlx5e: xsk: Support XDP metadata on XSK RQs Saeed Mahameed
2022-09-30 16:29 ` [PATCH net-next 15/16] net/mlx5e: Introduce the mlx5e_flush_rq function Saeed Mahameed
2022-09-30 16:29 ` [PATCH net-next 16/16] net/mlx5e: xsk: Use queue indices starting from 0 for XSK queues Saeed Mahameed
2022-10-01 20:40 ` [PATCH net-next 00/16] mlx5 xsk updates part3 2022-09-30 patchwork-bot+netdevbpf

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