lib: objagg: implement optimization hints assembly and use hints for …

…object creation

Implement simple greedy algo to find more optimized root-delta tree for
a given objagg instance. This "hints" can be used by a driver to:
1) check if the hints are better (driver's choice) than the original
   objagg tree. Driver does comparison of objagg stats and hints stats.
2) use the hints to create a new objagg instance which will construct
   the root-delta tree according to the passed hints. Currently, only a
   simple greedy algorithm is implemented. Basically it finds the roots
   according to the maximal possible user count including deltas.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/spectrum_acl_erp.c

@@ -1200,6 +1200,32 @@ mlxsw_sp_acl_erp_delta_fill(const struct mlxsw_sp_acl_erp_key *parent_key,
  return 0;
 }
 
+static bool mlxsw_sp_acl_erp_delta_check(void *priv, const void *parent_obj,
+ const void *obj)
+{
+ const struct mlxsw_sp_acl_erp_key *parent_key = parent_obj;
+ const struct mlxsw_sp_acl_erp_key *key = obj;
+ u16 delta_start;
+ u8 delta_mask;
+ int err;
+
+ err = mlxsw_sp_acl_erp_delta_fill(parent_key, key,
+ &delta_start, &delta_mask);
+ return err ? false : true;
+}
+
+static int mlxsw_sp_acl_erp_hints_obj_cmp(const void *obj1, const void *obj2)
+{
+ const struct mlxsw_sp_acl_erp_key *key1 = obj1;
+ const struct mlxsw_sp_acl_erp_key *key2 = obj2;
+
+ /* For hints purposes, two objects are considered equal
+ * in case the masks are the same. Does not matter what
+ * the "ctcam" value is.
+ */
+ return memcmp(key1->mask, key2->mask, sizeof(key1->mask));
+}
+
 static void *mlxsw_sp_acl_erp_delta_create(void *priv, void *parent_obj,
  void *obj)
 {
@@ -1254,12 +1280,17 @@ static void mlxsw_sp_acl_erp_delta_destroy(void *priv, void *delta_priv)
  kfree(delta);
 }
 
-static void *mlxsw_sp_acl_erp_root_create(void *priv, void *obj)
+static void *mlxsw_sp_acl_erp_root_create(void *priv, void *obj,
+ unsigned int root_id)
 {
  struct mlxsw_sp_acl_atcam_region *aregion = priv;
  struct mlxsw_sp_acl_erp_table *erp_table = aregion->erp_table;
  struct mlxsw_sp_acl_erp_key *key = obj;
 
+ if (!key->ctcam &&
+ root_id != OBJAGG_OBJ_ROOT_ID_INVALID &&
+ root_id >= MLXSW_SP_ACL_ERP_MAX_PER_REGION)
+ return ERR_PTR(-ENOBUFS);
  return erp_table->ops->erp_create(erp_table, key);
 }
 
@@ -1273,6 +1304,8 @@ static void mlxsw_sp_acl_erp_root_destroy(void *priv, void *root_priv)
 
 static const struct objagg_ops mlxsw_sp_acl_erp_objagg_ops = {
  .obj_size = sizeof(struct mlxsw_sp_acl_erp_key),
+ .delta_check = mlxsw_sp_acl_erp_delta_check,
+ .hints_obj_cmp = mlxsw_sp_acl_erp_hints_obj_cmp,
  .delta_create = mlxsw_sp_acl_erp_delta_create,
  .delta_destroy = mlxsw_sp_acl_erp_delta_destroy,
  .root_create = mlxsw_sp_acl_erp_root_create,
@@ -1290,7 +1323,7 @@ mlxsw_sp_acl_erp_table_create(struct mlxsw_sp_acl_atcam_region *aregion)
  return ERR_PTR(-ENOMEM);
 
  erp_table->objagg = objagg_create(&mlxsw_sp_acl_erp_objagg_ops,
- aregion);
+ NULL, aregion);
  if (IS_ERR(erp_table->objagg)) {
  err = PTR_ERR(erp_table->objagg);
  goto err_objagg_create;

include/linux/objagg.h

@@ -6,22 +6,28 @@
 
 struct objagg_ops {
  size_t obj_size;
+ bool (*delta_check)(void *priv, const void *parent_obj,
+ const void *obj);
+ int (*hints_obj_cmp)(const void *obj1, const void *obj2);
  void * (*delta_create)(void *priv, void *parent_obj, void *obj);
  void (*delta_destroy)(void *priv, void *delta_priv);
- void * (*root_create)(void *priv, void *obj);
+ void * (*root_create)(void *priv, void *obj, unsigned int root_id);
+#define OBJAGG_OBJ_ROOT_ID_INVALID UINT_MAX
  void (*root_destroy)(void *priv, void *root_priv);
 };
 
 struct objagg;
 struct objagg_obj;
+struct objagg_hints;
 
 const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj);
 const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj);
 const void *objagg_obj_raw(const struct objagg_obj *objagg_obj);
 
 struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj);
 void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj);
-struct objagg *objagg_create(const struct objagg_ops *ops, void *priv);
+struct objagg *objagg_create(const struct objagg_ops *ops,
+ struct objagg_hints *hints, void *priv);
 void objagg_destroy(struct objagg *objagg);
 
 struct objagg_obj_stats {
@@ -43,4 +49,14 @@ struct objagg_stats {
 const struct objagg_stats *objagg_stats_get(struct objagg *objagg);
 void objagg_stats_put(const struct objagg_stats *objagg_stats);
 
+enum objagg_opt_algo_type {
+ OBJAGG_OPT_ALGO_SIMPLE_GREEDY,
+};
+
+struct objagg_hints *objagg_hints_get(struct objagg *objagg,
+ enum objagg_opt_algo_type opt_algo_type);
+void objagg_hints_put(struct objagg_hints *objagg_hints);
+const struct objagg_stats *
+objagg_hints_stats_get(struct objagg_hints *objagg_hints);
+
 #endif