From 3ee7fedb0cc980a0923043e8dd7b87ec83998925 Mon Sep 17 00:00:00 2001
From: Alaa Hleihel <ahleihel@redhat.com>
Date: Sun, 10 May 2020 15:04:07 -0400
Subject: [PATCH 089/312] [netdrv] net/mlx5: Do not hold group lock while
 allocating FTE in software

Message-id: <20200510150452.10307-43-ahleihel@redhat.com>
Patchwork-id: 306666
Patchwork-instance: patchwork
O-Subject: [RHEL8.3 BZ 1789380 v2 42/87] net/mlx5: Do not hold group lock while allocating FTE in software
Bugzilla: 1789380
RH-Acked-by: Kamal Heib <kheib@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>
RH-Acked-by: Tony Camuso <tcamuso@redhat.com>
RH-Acked-by: Jonathan Toppins <jtoppins@redhat.com>

Bugzilla: http://bugzilla.redhat.com/1789380
Upstream: v5.5-rc1

commit 84c7af637512be9c3254189bd5910dae0d2a8602
Author: Parav Pandit <parav@mellanox.com>
Date:   Thu Sep 19 17:22:19 2019 -0500

    net/mlx5: Do not hold group lock while allocating FTE in software

    FTE memory allocation using alloc_fte() doesn't have any dependency
    on the flow group.
    Hence, do not hold flow group lock while performing alloc_fte().
    This helps to reduce contention of flow group lock.

    Signed-off-by: Parav Pandit <parav@mellanox.com>
    Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
    Reviewed-by: Mark Bloch <markb@mellanox.com>
    Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Signed-off-by: Alaa Hleihel <ahleihel@redhat.com>
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
index 495396f42153..e8064bd87aad 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -1817,6 +1817,13 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
 		return rule;
 	}
 
+	fte = alloc_fte(ft, spec, flow_act);
+	if (IS_ERR(fte)) {
+		up_write_ref_node(&ft->node, false);
+		err = PTR_ERR(fte);
+		goto err_alloc_fte;
+	}
+
 	nested_down_write_ref_node(&g->node, FS_LOCK_PARENT);
 	up_write_ref_node(&ft->node, false);
 
@@ -1824,17 +1831,9 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
 	if (err)
 		goto err_release_fg;
 
-	fte = alloc_fte(ft, spec, flow_act);
-	if (IS_ERR(fte)) {
-		err = PTR_ERR(fte);
-		goto err_release_fg;
-	}
-
 	err = insert_fte(g, fte);
-	if (err) {
-		kmem_cache_free(steering->ftes_cache, fte);
+	if (err)
 		goto err_release_fg;
-	}
 
 	nested_down_write_ref_node(&fte->node, FS_LOCK_CHILD);
 	up_write_ref_node(&g->node, false);
@@ -1846,6 +1845,8 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
 
 err_release_fg:
 	up_write_ref_node(&g->node, false);
+	kmem_cache_free(steering->ftes_cache, fte);
+err_alloc_fte:
 	tree_put_node(&g->node, false);
 	return ERR_PTR(err);
 }
-- 
2.13.6