[PATCH 5.3 10/95] net/mlx5: Fix auto group size calculation

[Greg Kroah-Hartman]

From: Maor Gottlieb <maorg@xxxxxxxxxxxx>

[ Upstream commit 97fd8da281f80e7e69e0114bc906575734d4dfaf ]

Once all the large flow groups (defined by the user when the flow table
is created - max_num_groups) were created, then all the following new
flow groups will have only one flow table entry, even though the flow table
has place to larger groups.
Fix the condition to prefer large flow group.

Fixes: f0d22d187473 ("net/mlx5_core: Introduce flow steering autogrouped flow table")
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
Signed-off-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.c |   10 ++++++----
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.h |    1 +
 2 files changed, 7 insertions(+), 4 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -549,7 +549,7 @@ static void del_sw_flow_group(struct fs_
 
 	rhashtable_destroy(&fg->ftes_hash);
 	ida_destroy(&fg->fte_allocator);
-	if (ft->autogroup.active)
+	if (ft->autogroup.active && fg->max_ftes == ft->autogroup.group_size)
 		ft->autogroup.num_groups--;
 	err = rhltable_remove(&ft->fgs_hash,
 			      &fg->hash,
@@ -1095,6 +1095,8 @@ mlx5_create_auto_grouped_flow_table(stru
 
 	ft->autogroup.active = true;
 	ft->autogroup.required_groups = max_num_groups;
+	/* We save place for flow groups in addition to max types */
+	ft->autogroup.group_size = ft->max_fte / (max_num_groups + 1);
 
 	return ft;
 }
@@ -1297,8 +1299,7 @@ static struct mlx5_flow_group *alloc_aut
 		return ERR_PTR(-ENOENT);
 
 	if (ft->autogroup.num_groups < ft->autogroup.required_groups)
-		/* We save place for flow groups in addition to max types */
-		group_size = ft->max_fte / (ft->autogroup.required_groups + 1);
+		group_size = ft->autogroup.group_size;
 
 	/*  ft->max_fte == ft->autogroup.max_types */
 	if (group_size == 0)
@@ -1325,7 +1326,8 @@ static struct mlx5_flow_group *alloc_aut
 	if (IS_ERR(fg))
 		goto out;
 
-	ft->autogroup.num_groups++;
+	if (group_size == ft->autogroup.group_size)
+		ft->autogroup.num_groups++;
 
 out:
 	return fg;
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
@@ -137,6 +137,7 @@ struct mlx5_flow_table {
 	struct {
 		bool			active;
 		unsigned int		required_groups;
+		unsigned int		group_size;
 		unsigned int		num_groups;
 	} autogroup;
 	/* Protect fwd_rules */