From: Paul Blakey <paulb@mellanox.com>
Date: Thu, 14 Nov 2019 17:02:59 +0200
Subject: net/mlx5: Allow creating autogroups with reserved entries
Patch-mainline: v5.6-rc1
Git-commit: 79cdb0aaea8b5478db34afa1d4d5ecc808689a67
References: jsc#SLE-8464

Exclude the last n entries for an autogrouped flow table.

Reserving entries at the end of the FT will ensure that this FG will be
the last to be evaluated. This will be used in the next patch to create
a miss group enabling custom actions on FT miss.

Signed-off-by: Paul Blakey <paulb@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.c |   26 ++++++++++++++--------
 drivers/net/ethernet/mellanox/mlx5/core/fs_core.h |    1 
 include/linux/mlx5/fs.h                           |    1 
 3 files changed, 19 insertions(+), 9 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c
@@ -579,7 +579,9 @@ static void del_sw_flow_group(struct fs_
 
 	rhashtable_destroy(&fg->ftes_hash);
 	ida_destroy(&fg->fte_allocator);
-	if (ft->autogroup.active && fg->max_ftes == ft->autogroup.group_size)
+	if (ft->autogroup.active &&
+	    fg->max_ftes == ft->autogroup.group_size &&
+	    fg->start_index < ft->autogroup.max_fte)
 		ft->autogroup.num_groups--;
 	err = rhltable_remove(&ft->fgs_hash,
 			      &fg->hash,
@@ -1121,9 +1123,14 @@ struct mlx5_flow_table*
 mlx5_create_auto_grouped_flow_table(struct mlx5_flow_namespace *ns,
 				    struct mlx5_flow_table_attr *ft_attr)
 {
+	int num_reserved_entries = ft_attr->autogroup.num_reserved_entries;
+	int autogroups_max_fte = ft_attr->max_fte - num_reserved_entries;
+	int max_num_groups = ft_attr->autogroup.max_num_groups;
 	struct mlx5_flow_table *ft;
 
-	if (ft_attr->autogroup.max_num_groups > ft_attr->max_fte)
+	if (max_num_groups > autogroups_max_fte)
+		return ERR_PTR(-EINVAL);
+	if (num_reserved_entries > ft_attr->max_fte)
 		return ERR_PTR(-EINVAL);
 
 	ft = mlx5_create_flow_table(ns, ft_attr);
@@ -1131,10 +1138,10 @@ mlx5_create_auto_grouped_flow_table(stru
 		return ft;
 
 	ft->autogroup.active = true;
-	ft->autogroup.required_groups = ft_attr->autogroup.max_num_groups;
+	ft->autogroup.required_groups = max_num_groups;
+	ft->autogroup.max_fte = autogroups_max_fte;
 	/* We save place for flow groups in addition to max types */
-	ft->autogroup.group_size = ft->max_fte /
-				   (ft->autogroup.required_groups + 1);
+	ft->autogroup.group_size = autogroups_max_fte / (max_num_groups + 1);
 
 	return ft;
 }
@@ -1156,7 +1163,7 @@ struct mlx5_flow_group *mlx5_create_flow
 	struct mlx5_flow_group *fg;
 	int err;
 
-	if (ft->autogroup.active)
+	if (ft->autogroup.active && start_index < ft->autogroup.max_fte)
 		return ERR_PTR(-EPERM);
 
 	down_write_ref_node(&ft->node, false);
@@ -1329,9 +1336,10 @@ static struct mlx5_flow_group *alloc_aut
 						     const struct mlx5_flow_spec *spec)
 {
 	struct list_head *prev = &ft->node.children;
-	struct mlx5_flow_group *fg;
+	u32 max_fte = ft->autogroup.max_fte;
 	unsigned int candidate_index = 0;
 	unsigned int group_size = 0;
+	struct mlx5_flow_group *fg;
 
 	if (!ft->autogroup.active)
 		return ERR_PTR(-ENOENT);
@@ -1339,7 +1347,7 @@ static struct mlx5_flow_group *alloc_aut
 	if (ft->autogroup.num_groups < ft->autogroup.required_groups)
 		group_size = ft->autogroup.group_size;
 
-	/*  ft->max_fte == ft->autogroup.max_types */
+	/*  max_fte == ft->autogroup.max_types */
 	if (group_size == 0)
 		group_size = 1;
 
@@ -1352,7 +1360,7 @@ static struct mlx5_flow_group *alloc_aut
 		prev = &fg->node.list;
 	}
 
-	if (candidate_index + group_size > ft->max_fte)
+	if (candidate_index + group_size > max_fte)
 		return ERR_PTR(-ENOSPC);
 
 	fg = alloc_insert_flow_group(ft,
--- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.h
@@ -164,6 +164,7 @@ struct mlx5_flow_table {
 		unsigned int		required_groups;
 		unsigned int		group_size;
 		unsigned int		num_groups;
+		unsigned int		max_fte;
 	} autogroup;
 	/* Protect fwd_rules */
 	struct mutex			lock;
--- a/include/linux/mlx5/fs.h
+++ b/include/linux/mlx5/fs.h
@@ -155,6 +155,7 @@ struct mlx5_flow_table_attr {
 
 	struct {
 		int max_num_groups;
+		int num_reserved_entries;
 	} autogroup;
 };