mlxsw: spectrum_acl: Allow encoding a partial key

When working with 12 key blocks in the A-TCAM, rules are split into two
records, which constitute two lookups. The two records are linked using
a "large entry key ID". The ID is assigned to key blocks 6 to 11 and
resolved during the first lookup. The second lookup is performed using
the ID and the remaining key blocks.

Allow encoding a partial key so that it can be later used to check if an
ID can be reused.

This is done by adding two arguments to the existing encode function
that specify the range of the block indexes we would like to encode. The
key and mask arguments become optional, as we will not need to encode
both of them all the time.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -457,7 +457,7 @@ mlxsw_sp_afk_encode_one(const struct mlxsw_afk_element_inst *elinst,
 void mlxsw_afk_encode(struct mlxsw_afk *mlxsw_afk,
 		      struct mlxsw_afk_key_info *key_info,
 		      struct mlxsw_afk_element_values *values,
-		      char *key, char *mask)
+		      char *key, char *mask, int block_start, int block_end)
 {
 	char block_mask[MLXSW_SP_AFK_KEY_BLOCK_MAX_SIZE];
 	char block_key[MLXSW_SP_AFK_KEY_BLOCK_MAX_SIZE];
@@ -465,7 +465,7 @@ void mlxsw_afk_encode(struct mlxsw_afk *mlxsw_afk,
 	enum mlxsw_afk_element element;
 	int block_index, i;
 
-	for (i = 0; i < key_info->blocks_count; i++) {
+	for (i = block_start; i <= block_end; i++) {
 		memset(block_key, 0, MLXSW_SP_AFK_KEY_BLOCK_MAX_SIZE);
 		memset(block_mask, 0, MLXSW_SP_AFK_KEY_BLOCK_MAX_SIZE);
 
@@ -482,7 +482,9 @@ void mlxsw_afk_encode(struct mlxsw_afk *mlxsw_afk,
 						values->storage.mask);
 		}
 
+		if (key)
 			mlxsw_afk->ops->encode_block(block_key, i, key);
+		if (mask)
 			mlxsw_afk->ops->encode_block(block_mask, i, mask);
 	}
 }

drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_keys.h

@@ -259,6 +259,6 @@ void mlxsw_afk_values_add_buf(struct mlxsw_afk_element_values *values,
 void mlxsw_afk_encode(struct mlxsw_afk *mlxsw_afk,
 		      struct mlxsw_afk_key_info *key_info,
 		      struct mlxsw_afk_element_values *values,
-		      char *key, char *mask);
+		      char *key, char *mask, int block_start, int block_end);
 
 #endif

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

@@ -76,6 +76,7 @@ mlxsw_sp_acl_ctcam_region_entry_insert(struct mlxsw_sp *mlxsw_sp,
 {
 	struct mlxsw_afk *afk = mlxsw_sp_acl_afk(mlxsw_sp->acl);
 	char ptce2_pl[MLXSW_REG_PTCE2_LEN];
+	unsigned int blocks_count;
 	char *act_set;
 	u32 priority;
 	char *mask;
@@ -91,7 +92,9 @@ mlxsw_sp_acl_ctcam_region_entry_insert(struct mlxsw_sp *mlxsw_sp,
 			     region->tcam_region_info, offset, priority);
 	key = mlxsw_reg_ptce2_flex_key_blocks_data(ptce2_pl);
 	mask = mlxsw_reg_ptce2_mask_data(ptce2_pl);
-	mlxsw_afk_encode(afk, region->key_info, &rulei->values, key, mask);
+	blocks_count = mlxsw_afk_key_info_blocks_count_get(region->key_info);
+	mlxsw_afk_encode(afk, region->key_info, &rulei->values, key, mask, 0,
+			 blocks_count - 1);
 
 	/* Only the first action set belongs here, the rest is in KVD */
 	act_set = mlxsw_afa_block_first_set(rulei->act_block);