net/mlx5: Refactor FTE and FG creation code

Split the creation code to two parts:
1) Object allocation - allocate the steering node and initialize
its resources.

2) The firmware command execution.

Adding active flag to each node - this flag indicates if the
object exists in the hardware or not, if not we don't free
the hardware resource in error flow.

This change will give us the ability to take write lock on the
parent node (e.g. FG for FTE creationg) only on the first part.

Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

@@ -179,14 +179,14 @@ find_flow_rule(struct fs_fte *fte,
 	       struct mlx5_flow_destination *dest);
 
 static void tree_init_node(struct fs_node *node,
-			   unsigned int refcount,
 			   void (*remove_func)(struct fs_node *))
 {
-	atomic_set(&node->refcount, refcount);
+	atomic_set(&node->refcount, 1);
 	INIT_LIST_HEAD(&node->list);
 	INIT_LIST_HEAD(&node->children);
 	mutex_init(&node->lock);
 	node->remove_func = remove_func;
+	node->active = false;
 }
 
 static void tree_add_node(struct fs_node *node, struct fs_node *parent)
@@ -381,9 +381,11 @@ static void del_flow_table(struct fs_node *node)
 	fs_get_obj(ft, node);
 	dev = get_dev(&ft->node);
 
-	err = mlx5_cmd_destroy_flow_table(dev, ft);
-	if (err)
-		mlx5_core_warn(dev, "flow steering can't destroy ft\n");
+	if (node->active) {
+		err = mlx5_cmd_destroy_flow_table(dev, ft);
+		if (err)
+			mlx5_core_warn(dev, "flow steering can't destroy ft\n");
+	}
 	rhltable_destroy(&ft->fgs_hash);
 	fs_get_obj(prio, ft->node.parent);
 	prio->num_ft--;
@@ -435,18 +437,6 @@ out:
 	}
 }
 
-static void destroy_fte(struct fs_fte *fte, struct mlx5_flow_group *fg)
-{
-	struct mlx5_flow_table *ft;
-	int ret;
-
-	ret = rhashtable_remove_fast(&fg->ftes_hash, &fte->hash, rhash_fte);
-	WARN_ON(ret);
-	fte->status = 0;
-	fs_get_obj(ft, fg->node.parent);
-	ida_simple_remove(&fg->fte_allocator, fte->index - fg->start_index);
-}
-
 static void del_fte(struct fs_node *node)
 {
 	struct mlx5_flow_table *ft;
@@ -461,14 +451,20 @@ static void del_fte(struct fs_node *node)
 	trace_mlx5_fs_del_fte(fte);
 
 	dev = get_dev(&ft->node);
-	err = mlx5_cmd_delete_fte(dev, ft,
-				  fte->index);
-	if (err)
-		mlx5_core_warn(dev,
-			       "flow steering can't delete fte in index %d of flow group id %d\n",
-			       fte->index, fg->id);
+	if (node->active) {
+		err = mlx5_cmd_delete_fte(dev, ft,
+					  fte->index);
+		if (err)
+			mlx5_core_warn(dev,
+				       "flow steering can't delete fte in index %d of flow group id %d\n",
+				       fte->index, fg->id);
+	}
 
-	destroy_fte(fte, fg);
+	err = rhashtable_remove_fast(&fg->ftes_hash,
+				     &fte->hash,
+				     rhash_fte);
+	WARN_ON(err);
+	ida_simple_remove(&fg->fte_allocator, fte->index - fg->start_index);
 }
 
 static void del_flow_group(struct fs_node *node)
@@ -492,7 +488,7 @@ static void del_flow_group(struct fs_node *node)
 			      &fg->hash,
 			      rhash_fg);
 	WARN_ON(err);
-	if (mlx5_cmd_destroy_flow_group(dev, ft, fg->id))
+	if (fg->node.active && mlx5_cmd_destroy_flow_group(dev, ft, fg->id))
 		mlx5_core_warn(dev, "flow steering can't destroy fg %d of ft %d\n",
 			       fg->id, ft->id);
 }
@@ -518,14 +514,57 @@ static struct fs_fte *alloc_fte(struct mlx5_flow_act *flow_act,
 	return fte;
 }
 
-static struct mlx5_flow_group *alloc_flow_group(u32 *create_fg_in)
+static struct fs_fte *alloc_insert_fte(struct mlx5_flow_group *fg,
+				       u32 *match_value,
+				       struct mlx5_flow_act *flow_act)
+{
+	struct fs_fte *fte;
+	int index;
+	int ret;
+
+	index = ida_simple_get(&fg->fte_allocator, 0,
+			       fg->max_ftes,
+			       GFP_KERNEL);
+	if (index < 0)
+		return ERR_PTR(index);
+
+	fte = alloc_fte(flow_act, match_value, index + fg->start_index);
+	if (IS_ERR(fte)) {
+		ret = PTR_ERR(fte);
+		goto err_ida_remove;
+	}
+
+	ret = rhashtable_insert_fast(&fg->ftes_hash,
+				     &fte->hash,
+				     rhash_fte);
+	if (ret)
+		goto err_free;
+
+	tree_init_node(&fte->node, del_fte);
+	tree_add_node(&fte->node, &fg->node);
+	list_add_tail(&fte->node.list, &fg->node.children);
+
+	return fte;
+
+err_free:
+	kfree(fte);
+err_ida_remove:
+	ida_simple_remove(&fg->fte_allocator, index);
+	return ERR_PTR(ret);
+}
+
+static void dealloc_flow_group(struct mlx5_flow_group *fg)
+{
+	rhashtable_destroy(&fg->ftes_hash);
+	kfree(fg);
+}
+
+static struct mlx5_flow_group *alloc_flow_group(u8 match_criteria_enable,
+						void *match_criteria,
+						int start_index,
+						int end_index)
 {
 	struct mlx5_flow_group *fg;
-	void *match_criteria = MLX5_ADDR_OF(create_flow_group_in,
-					    create_fg_in, match_criteria);
-	u8 match_criteria_enable = MLX5_GET(create_flow_group_in,
-					    create_fg_in,
-					    match_criteria_enable);
 	int ret;
 
 	fg = kzalloc(sizeof(*fg), GFP_KERNEL);
@@ -536,16 +575,47 @@ static struct mlx5_flow_group *alloc_flow_group(u32 *create_fg_in)
 	if (ret) {
 		kfree(fg);
 		return ERR_PTR(ret);
-	}
+}
 	ida_init(&fg->fte_allocator);
 	fg->mask.match_criteria_enable = match_criteria_enable;
 	memcpy(&fg->mask.match_criteria, match_criteria,
 	       sizeof(fg->mask.match_criteria));
 	fg->node.type =  FS_TYPE_FLOW_GROUP;
-	fg->start_index = MLX5_GET(create_flow_group_in, create_fg_in,
-				   start_flow_index);
-	fg->max_ftes = MLX5_GET(create_flow_group_in, create_fg_in,
-				end_flow_index) - fg->start_index + 1;
+	fg->start_index = start_index;
+	fg->max_ftes = end_index - start_index + 1;
+
+	return fg;
+}
+
+static struct mlx5_flow_group *alloc_insert_flow_group(struct mlx5_flow_table *ft,
+						       u8 match_criteria_enable,
+						       void *match_criteria,
+						       int start_index,
+						       int end_index,
+						       struct list_head *prev)
+{
+	struct mlx5_flow_group *fg;
+	int ret;
+
+	fg = alloc_flow_group(match_criteria_enable, match_criteria,
+			      start_index, end_index);
+	if (IS_ERR(fg))
+		return fg;
+
+	/* initialize refcnt, add to parent list */
+	ret = rhltable_insert(&ft->fgs_hash,
+			      &fg->hash,
+			      rhash_fg);
+	if (ret) {
+		dealloc_flow_group(fg);
+		return ERR_PTR(ret);
+	}
+
+	tree_init_node(&fg->node, del_flow_group);
+	tree_add_node(&fg->node, &ft->node);
+	/* Add node to group list */
+	list_add(&fg->node.list, prev);
+
 	return fg;
 }
 
@@ -870,7 +940,7 @@ static struct mlx5_flow_table *__mlx5_create_flow_table(struct mlx5_flow_namespa
 		goto unlock_root;
 	}
 
-	tree_init_node(&ft->node, 1, del_flow_table);
+	tree_init_node(&ft->node, del_flow_table);
 	log_table_sz = ft->max_fte ? ilog2(ft->max_fte) : 0;
 	next_ft = find_next_chained_ft(fs_prio);
 	err = mlx5_cmd_create_flow_table(root->dev, ft->vport, ft->op_mod, ft->type,
@@ -882,6 +952,7 @@ static struct mlx5_flow_table *__mlx5_create_flow_table(struct mlx5_flow_namespa
 	err = connect_flow_table(root->dev, ft, fs_prio);
 	if (err)
 		goto destroy_ft;
+	ft->node.active = true;
 	lock_ref_node(&fs_prio->node);
 	tree_add_node(&ft->node, &fs_prio->node);
 	list_add_flow_table(ft, fs_prio);
@@ -959,55 +1030,6 @@ mlx5_create_auto_grouped_flow_table(struct mlx5_flow_namespace *ns,
 }
 EXPORT_SYMBOL(mlx5_create_auto_grouped_flow_table);
 
-/* Flow table should be locked */
-static struct mlx5_flow_group *create_flow_group_common(struct mlx5_flow_table *ft,
-							u32 *fg_in,
-							struct list_head
-							*prev_fg,
-							bool is_auto_fg)
-{
-	struct mlx5_flow_group *fg;
-	struct mlx5_core_dev *dev = get_dev(&ft->node);
-	int err;
-
-	if (!dev)
-		return ERR_PTR(-ENODEV);
-
-	fg = alloc_flow_group(fg_in);
-	if (IS_ERR(fg))
-		return fg;
-
-	err = rhltable_insert(&ft->fgs_hash, &fg->hash, rhash_fg);
-	if (err)
-		goto err_free_fg;
-
-	err = mlx5_cmd_create_flow_group(dev, ft, fg_in, &fg->id);
-	if (err)
-		goto err_remove_fg;
-
-	if (ft->autogroup.active)
-		ft->autogroup.num_groups++;
-	/* Add node to tree */
-	tree_init_node(&fg->node, !is_auto_fg, del_flow_group);
-	tree_add_node(&fg->node, &ft->node);
-	/* Add node to group list */
-	list_add(&fg->node.list, prev_fg);
-
-	trace_mlx5_fs_add_fg(fg);
-	return fg;
-
-err_remove_fg:
-	WARN_ON(rhltable_remove(&ft->fgs_hash,
-				&fg->hash,
-				rhash_fg));
-err_free_fg:
-	rhashtable_destroy(&fg->ftes_hash);
-	ida_destroy(&fg->fte_allocator);
-	kfree(fg);
-
-	return ERR_PTR(err);
-}
-
 struct mlx5_flow_group *mlx5_create_flow_group(struct mlx5_flow_table *ft,
 					       u32 *fg_in)
 {
@@ -1016,7 +1038,13 @@ struct mlx5_flow_group *mlx5_create_flow_group(struct mlx5_flow_table *ft,
 	u8 match_criteria_enable = MLX5_GET(create_flow_group_in,
 					    fg_in,
 					    match_criteria_enable);
+	int start_index = MLX5_GET(create_flow_group_in, fg_in,
+				   start_flow_index);
+	int end_index = MLX5_GET(create_flow_group_in, fg_in,
+				 end_flow_index);
+	struct mlx5_core_dev *dev = get_dev(&ft->node);
 	struct mlx5_flow_group *fg;
+	int err;
 
 	if (!check_valid_mask(match_criteria_enable, match_criteria))
 		return ERR_PTR(-EINVAL);
@@ -1025,8 +1053,20 @@ struct mlx5_flow_group *mlx5_create_flow_group(struct mlx5_flow_table *ft,
 		return ERR_PTR(-EPERM);
 
 	lock_ref_node(&ft->node);
-	fg = create_flow_group_common(ft, fg_in, ft->node.children.prev, false);
+	fg = alloc_insert_flow_group(ft, match_criteria_enable, match_criteria,
+				     start_index, end_index,
+				     ft->node.children.prev);
 	unlock_ref_node(&ft->node);
+	if (IS_ERR(fg))
+		return fg;
+
+	err = mlx5_cmd_create_flow_group(dev, ft, fg_in, &fg->id);
+	if (err) {
+		tree_put_node(&fg->node);
+		return ERR_PTR(err);
+	}
+	trace_mlx5_fs_add_fg(fg);
+	fg->node.active = true;
 
 	return fg;
 }
@@ -1111,7 +1151,7 @@ create_flow_handle(struct fs_fte *fte,
 		/* Add dest to dests list- we need flow tables to be in the
 		 * end of the list for forward to next prio rules.
 		 */
-		tree_init_node(&rule->node, 1, del_rule);
+		tree_init_node(&rule->node, del_rule);
 		if (dest &&
 		    dest[i].type != MLX5_FLOW_DESTINATION_TYPE_FLOW_TABLE)
 			list_add(&rule->node.list, &fte->node.children);
@@ -1167,6 +1207,7 @@ add_rule_fte(struct fs_fte *fte,
 	if (err)
 		goto free_handle;
 
+	fte->node.active = true;
 	fte->status |= FS_FTE_STATUS_EXISTING;
 
 out:
@@ -1177,59 +1218,17 @@ free_handle:
 	return ERR_PTR(err);
 }
 
-static struct fs_fte *create_fte(struct mlx5_flow_group *fg,
-				 u32 *match_value,
-				 struct mlx5_flow_act *flow_act)
+static struct mlx5_flow_group *alloc_auto_flow_group(struct mlx5_flow_table  *ft,
+						     struct mlx5_flow_spec *spec)
 {
-	struct fs_fte *fte;
-	int index;
-	int ret;
-
-	index = ida_simple_get(&fg->fte_allocator, 0,
-			       fg->max_ftes,
-			       GFP_KERNEL);
-	if (index < 0)
-		return ERR_PTR(index);
-
-	index += fg->start_index;
-
-	fte = alloc_fte(flow_act, match_value, index);
-	if (IS_ERR(fte)) {
-		ret = PTR_ERR(fte);
-		goto err_alloc;
-	}
-	ret = rhashtable_insert_fast(&fg->ftes_hash, &fte->hash, rhash_fte);
-	if (ret)
-		goto err_hash;
-
-	return fte;
-
-err_hash:
-	kfree(fte);
-err_alloc:
-	ida_simple_remove(&fg->fte_allocator, index - fg->start_index);
-	return ERR_PTR(ret);
-}
-
-static struct mlx5_flow_group *create_autogroup(struct mlx5_flow_table *ft,
-						u8 match_criteria_enable,
-						u32 *match_criteria)
-{
-	int inlen = MLX5_ST_SZ_BYTES(create_flow_group_in);
 	struct list_head *prev = &ft->node.children;
-	unsigned int candidate_index = 0;
 	struct mlx5_flow_group *fg;
-	void *match_criteria_addr;
+	unsigned int candidate_index = 0;
 	unsigned int group_size = 0;
-	u32 *in;
 
 	if (!ft->autogroup.active)
 		return ERR_PTR(-ENOENT);
 
-	in = kvzalloc(inlen, GFP_KERNEL);
-	if (!in)
-		return ERR_PTR(-ENOMEM);
-
 	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);
@@ -1247,25 +1246,55 @@ static struct mlx5_flow_group *create_autogroup(struct mlx5_flow_table *ft,
 		prev = &fg->node.list;
 	}
 
-	if (candidate_index + group_size > ft->max_fte) {
-		fg = ERR_PTR(-ENOSPC);
+	if (candidate_index + group_size > ft->max_fte)
+		return ERR_PTR(-ENOSPC);
+
+	fg = alloc_insert_flow_group(ft,
+				     spec->match_criteria_enable,
+				     spec->match_criteria,
+				     candidate_index,
+				     candidate_index + group_size - 1,
+				     prev);
+	if (IS_ERR(fg))
 		goto out;
-	}
+
+	ft->autogroup.num_groups++;
+
+out:
+	return fg;
+}
+
+static int create_auto_flow_group(struct mlx5_flow_table *ft,
+				  struct mlx5_flow_group *fg)
+{
+	struct mlx5_core_dev *dev = get_dev(&ft->node);
+	int inlen = MLX5_ST_SZ_BYTES(create_flow_group_in);
+	void *match_criteria_addr;
+	int err;
+	u32 *in;
+
+	in = kvzalloc(inlen, GFP_KERNEL);
+	if (!in)
+		return -ENOMEM;
 
 	MLX5_SET(create_flow_group_in, in, match_criteria_enable,
-		 match_criteria_enable);
-	MLX5_SET(create_flow_group_in, in, start_flow_index, candidate_index);
-	MLX5_SET(create_flow_group_in, in, end_flow_index,   candidate_index +
-		 group_size - 1);
+		 fg->mask.match_criteria_enable);
+	MLX5_SET(create_flow_group_in, in, start_flow_index, fg->start_index);
+	MLX5_SET(create_flow_group_in, in, end_flow_index,   fg->start_index +
+		 fg->max_ftes - 1);
 	match_criteria_addr = MLX5_ADDR_OF(create_flow_group_in,
 					   in, match_criteria);
-	memcpy(match_criteria_addr, match_criteria,
-	       MLX5_ST_SZ_BYTES(fte_match_param));
+	memcpy(match_criteria_addr, fg->mask.match_criteria,
+	       sizeof(fg->mask.match_criteria));
+
+	err = mlx5_cmd_create_flow_group(dev, ft, in, &fg->id);
+	if (!err) {
+		fg->node.active = true;
+		trace_mlx5_fs_add_fg(fg);
+	}
 
-	fg = create_flow_group_common(ft, in, prev, true);
-out:
 	kvfree(in);
-	return fg;
+	return err;
 }
 
 static bool mlx5_flow_dests_cmp(struct mlx5_flow_destination *d1,
@@ -1368,23 +1397,17 @@ static struct mlx5_flow_handle *add_rule_fg(struct mlx5_flow_group *fg,
 	}
 	fs_get_obj(ft, fg->node.parent);
 
-	fte = create_fte(fg, match_value, flow_act);
+	fte = alloc_insert_fte(fg, match_value, flow_act);
 	if (IS_ERR(fte))
 		return (void *)fte;
-	tree_init_node(&fte->node, 0, del_fte);
 	nested_lock_ref_node(&fte->node, FS_MUTEX_CHILD);
 	handle = add_rule_fte(fte, fg, dest, dest_num, false);
 	if (IS_ERR(handle)) {
 		unlock_ref_node(&fte->node);
-		destroy_fte(fte, fg);
-		kfree(fte);
+		tree_put_node(&fte->node);
 		return handle;
 	}
 
-	tree_add_node(&fte->node, &fg->node);
-	/* fte list isn't sorted */
-	list_add_tail(&fte->node.list, &fg->node.children);
-	trace_mlx5_fs_set_fte(fte, true);
 add_rules:
 	for (i = 0; i < handle->num_rules; i++) {
 		if (atomic_read(&handle->rule[i]->node.refcount) == 1) {
@@ -1571,6 +1594,7 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
 {
 	struct mlx5_flow_group *g;
 	struct mlx5_flow_handle *rule;
+	int err;
 	int i;
 
 	if (!check_valid_spec(spec))
@@ -1586,24 +1610,22 @@ _mlx5_add_flow_rules(struct mlx5_flow_table *ft,
 	if (!IS_ERR(rule) || PTR_ERR(rule) != -ENOENT)
 		goto unlock;
 
-	g = create_autogroup(ft, spec->match_criteria_enable,
-			     spec->match_criteria);
+	g = alloc_auto_flow_group(ft, spec);
 	if (IS_ERR(g)) {
 		rule = (void *)g;
 		goto unlock;
 	}
 
+	err = create_auto_flow_group(ft, g);
+	if (err) {
+		rule = ERR_PTR(err);
+		goto put_fg;
+	}
+
 	rule = add_rule_fg(g, spec->match_value, flow_act, dest,
 			   dest_num, NULL);
-	if (IS_ERR(rule)) {
-		/* Remove assumes refcount > 0 and autogroup creates a group
-		 * with a refcount = 0.
-		 */
-		unlock_ref_node(&ft->node);
-		tree_get_node(&g->node);
-		tree_remove_node(&g->node);
-		return rule;
-	}
+put_fg:
+	tree_put_node(&g->node);
 unlock:
 	unlock_ref_node(&ft->node);
 	return rule;
@@ -1847,7 +1869,7 @@ static struct fs_prio *fs_create_prio(struct mlx5_flow_namespace *ns,
 		return ERR_PTR(-ENOMEM);
 
 	fs_prio->node.type = FS_TYPE_PRIO;
-	tree_init_node(&fs_prio->node, 1, NULL);
+	tree_init_node(&fs_prio->node, NULL);
 	tree_add_node(&fs_prio->node, &ns->node);
 	fs_prio->num_levels = num_levels;
 	fs_prio->prio = prio;
@@ -1873,7 +1895,7 @@ static struct mlx5_flow_namespace *fs_create_namespace(struct fs_prio *prio)
 		return ERR_PTR(-ENOMEM);
 
 	fs_init_namespace(ns);
-	tree_init_node(&ns->node, 1, NULL);
+	tree_init_node(&ns->node, NULL);
 	tree_add_node(&ns->node, &prio->node);
 	list_add_tail(&ns->node.list, &prio->node.children);
 
@@ -1998,7 +2020,7 @@ static struct mlx5_flow_root_namespace *create_root_ns(struct mlx5_flow_steering
 	ns = &root_ns->ns;
 	fs_init_namespace(ns);
 	mutex_init(&root_ns->chain_lock);
-	tree_init_node(&ns->node, 1, NULL);
+	tree_init_node(&ns->node, NULL);
 	tree_add_node(&ns->node, NULL);
 
 	return root_ns;

drivers/net/ethernet/mellanox/mlx5/core/fs_core.h

@@ -82,6 +82,7 @@ struct fs_node {
 	/* lock the node for writing and traversing */
 	struct mutex		lock;
 	atomic_t		refcount;
+	bool			active;
 	void			(*remove_func)(struct fs_node *);
 };