From: Maxim Mikityanskiy <maximmi@nvidia.com>
Date: Sat, 1 Oct 2022 21:56:18 -0700
Subject: net/mlx5e: xsk: Flush RQ on XSK activation to save memory
Patch-mainline: v6.1-rc1
Git-commit: 082a9edf12fef88400172e7d1b131d65a3ed492e
References: jsc#PED-1549

The regular RQ remains open after opening an XSK socket, in order to
guarantee that closing the XSK socket never fails due to an error when
reopening the regular RQ.

To save memory, the regular RQ can be deactivated and flushed, releasing
all pages, when an XSK socket is open.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/en.h          |    1 +
 drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c |    9 +++++++++
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c     |   14 +++++++++-----
 3 files changed, 19 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -1036,6 +1036,7 @@ struct mlx5e_rq_param;
 int mlx5e_open_rq(struct mlx5e_params *params, struct mlx5e_rq_param *param,
 		  struct mlx5e_xsk_param *xsk, int node,
 		  struct mlx5e_rq *rq);
+#define MLX5E_RQ_WQES_TIMEOUT 20000 /* msecs */
 int mlx5e_wait_for_min_rx_wqes(struct mlx5e_rq *rq, int wait_time);
 void mlx5e_close_rq(struct mlx5e_rq *rq);
 int mlx5e_create_rq(struct mlx5e_rq *rq, struct mlx5e_rq_param *param);
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c
@@ -126,6 +126,9 @@ static int mlx5e_xsk_enable_locked(struc
 
 	mlx5e_rx_res_xsk_update(priv->rx_res, &priv->channels, ix, true);
 
+	mlx5e_deactivate_rq(&c->rq);
+	mlx5e_flush_rq(&c->rq, MLX5_RQC_STATE_RDY);
+
 	return 0;
 
 err_remove_pool:
@@ -165,7 +168,13 @@ static int mlx5e_xsk_disable_locked(stru
 		goto remove_pool;
 
 	c = priv->channels.c[ix];
+
+	mlx5e_activate_rq(&c->rq);
+	mlx5e_trigger_napi_icosq(c);
+	mlx5e_wait_for_min_rx_wqes(&c->rq, MLX5E_RQ_WQES_TIMEOUT);
+
 	mlx5e_rx_res_xsk_update(priv->rx_res, &priv->channels, ix, false);
+
 	mlx5e_deactivate_xsk(c);
 	mlx5e_close_xsk(c);
 
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -2408,10 +2408,11 @@ static void mlx5e_activate_channel(struc
 		mlx5e_activate_txqsq(&c->sq[tc]);
 	mlx5e_activate_icosq(&c->icosq);
 	mlx5e_activate_icosq(&c->async_icosq);
-	mlx5e_activate_rq(&c->rq);
 
 	if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state))
 		mlx5e_activate_xsk(c);
+	else
+		mlx5e_activate_rq(&c->rq);
 
 	mlx5e_trigger_napi_icosq(c);
 }
@@ -2422,8 +2423,9 @@ static void mlx5e_deactivate_channel(str
 
 	if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state))
 		mlx5e_deactivate_xsk(c);
+	else
+		mlx5e_deactivate_rq(&c->rq);
 
-	mlx5e_deactivate_rq(&c->rq);
 	mlx5e_deactivate_icosq(&c->async_icosq);
 	mlx5e_deactivate_icosq(&c->icosq);
 	for (tc = 0; tc < c->num_tc; tc++)
@@ -2515,8 +2517,6 @@ static void mlx5e_activate_channels(stru
 		mlx5e_ptp_activate_channel(chs->ptp);
 }
 
-#define MLX5E_RQ_WQES_TIMEOUT 20000 /* msecs */
-
 static int mlx5e_wait_channels_min_rx_wqes(struct mlx5e_channels *chs)
 {
 	int err = 0;
@@ -2524,8 +2524,12 @@ static int mlx5e_wait_channels_min_rx_wq
 
 	for (i = 0; i < chs->num; i++) {
 		int timeout = err ? 0 : MLX5E_RQ_WQES_TIMEOUT;
+		struct mlx5e_channel *c = chs->c[i];
+
+		if (test_bit(MLX5E_CHANNEL_STATE_XSK, c->state))
+			continue;
 
-		err |= mlx5e_wait_for_min_rx_wqes(&chs->c[i]->rq, timeout);
+		err |= mlx5e_wait_for_min_rx_wqes(&c->rq, timeout);
 
 		/* Don't wait on the XSK RQ, because the newer xdpsock sample
 		 * doesn't provide any Fill Ring entries at the setup stage.