From: Yevgeny Kliteynik Date: Tue, 20 May 2025 18:46:42 +0000 (+0300) Subject: net/mlx5: HWS, handle modify header actions dependency X-Git-Tag: v6.16-rc1~132^2~52^2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=01e035fd0380b285d72725adb5a45f1d73549db8;p=linux-block.git net/mlx5: HWS, handle modify header actions dependency Having adjacent accelerated modify header actions (so-called pattern-argument actions) may result in inconsistent outcome. These inconsistencies can take the form of writes to the same field or a read coupled with a write to the same field. The solution is to detect such dependencies and insert nops between the offending actions. The existing implementation had a few issues, which pretty much required a complete rewrite of the code that handles these dependencies. In the new implementation we're doing the following: * Checking any two adjacent actions for conflicts (not just odd-even pairs). * Marking 'set' and 'add' action fields as destination, rather than source, for the purposes of checking for conflicts. * Checking all types of actions ('add', 'set', 'copy') for dependencies. * Managing offsets of the args in the buffer - copy the action args to the right place in the buffer. * Checking that after inserting nops we're still within the number of supported actions - return an error otherwise. Signed-off-by: Vlad Dogaru Signed-off-by: Yevgeny Kliteynik Reviewed-by: Mark Bloch Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/1747766802-958178-5-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/action.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/action.c index 64d115feef2c..fb62f3bc4bd4 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/action.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/action.c @@ -1190,14 +1190,15 @@ hws_action_create_modify_header_hws(struct mlx5hws_action *action, struct mlx5hws_action_mh_pattern *pattern, u32 log_bulk_size) { + u16 num_actions, max_mh_actions = 0, hw_max_actions; struct mlx5hws_context *ctx = action->ctx; - u16 num_actions, max_mh_actions = 0; int i, ret, size_in_bytes; u32 pat_id, arg_id = 0; __be64 *new_pattern; size_t pat_max_sz; pat_max_sz = MLX5HWS_ARG_CHUNK_SIZE_MAX * MLX5HWS_ARG_DATA_SIZE; + hw_max_actions = pat_max_sz / MLX5HWS_MODIFY_ACTION_SIZE; size_in_bytes = pat_max_sz * sizeof(__be64); new_pattern = kcalloc(num_of_patterns, size_in_bytes, GFP_KERNEL); if (!new_pattern) @@ -1211,10 +1212,14 @@ hws_action_create_modify_header_hws(struct mlx5hws_action *action, cur_num_actions = pattern[i].sz / MLX5HWS_MODIFY_ACTION_SIZE; - mlx5hws_pat_calc_nop(pattern[i].data, cur_num_actions, - pat_max_sz / MLX5HWS_MODIFY_ACTION_SIZE, - &new_num_actions, &nop_locations, - &new_pattern[i * pat_max_sz]); + ret = mlx5hws_pat_calc_nop(pattern[i].data, cur_num_actions, + hw_max_actions, &new_num_actions, + &nop_locations, + &new_pattern[i * pat_max_sz]); + if (ret) { + mlx5hws_err(ctx, "Too many actions after nop insertion\n"); + goto free_new_pat; + } action[i].modify_header.nop_locations = nop_locations; action[i].modify_header.num_of_actions = new_num_actions; @@ -2116,10 +2121,12 @@ static void hws_action_modify_write(struct mlx5hws_send_engine *queue, if (unlikely(!new_arg_data)) return; - for (i = 0, j = 0; i < num_of_actions; i++, j++) { - memcpy(&new_arg_data[j], arg_data, MLX5HWS_MODIFY_ACTION_SIZE); + for (i = 0, j = 0; j < num_of_actions; i++, j++) { if (BIT(i) & nop_locations) j++; + memcpy(&new_arg_data[j * MLX5HWS_MODIFY_ACTION_SIZE], + &arg_data[i * MLX5HWS_MODIFY_ACTION_SIZE], + MLX5HWS_MODIFY_ACTION_SIZE); } } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.c b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.c index 78de19c074a7..51e4c551e0ef 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.c @@ -490,8 +490,8 @@ hws_action_modify_get_target_fields(u8 action_type, __be64 *pattern, switch (action_type) { case MLX5_ACTION_TYPE_SET: case MLX5_ACTION_TYPE_ADD: - *src_field = MLX5_GET(set_action_in, pattern, field); - *dst_field = INVALID_FIELD; + *src_field = INVALID_FIELD; + *dst_field = MLX5_GET(set_action_in, pattern, field); break; case MLX5_ACTION_TYPE_COPY: *src_field = MLX5_GET(copy_action_in, pattern, src_field); @@ -522,57 +522,59 @@ bool mlx5hws_pat_verify_actions(struct mlx5hws_context *ctx, __be64 pattern[], s return true; } -void mlx5hws_pat_calc_nop(__be64 *pattern, size_t num_actions, - size_t max_actions, size_t *new_size, - u32 *nop_locations, __be64 *new_pat) +int mlx5hws_pat_calc_nop(__be64 *pattern, size_t num_actions, + size_t max_actions, size_t *new_size, + u32 *nop_locations, __be64 *new_pat) { - u16 prev_src_field = 0, prev_dst_field = 0; + u16 prev_src_field = INVALID_FIELD, prev_dst_field = INVALID_FIELD; u16 src_field, dst_field; u8 action_type; + bool dependent; size_t i, j; *new_size = num_actions; *nop_locations = 0; if (num_actions == 1) - return; + return 0; for (i = 0, j = 0; i < num_actions; i++, j++) { - action_type = MLX5_GET(set_action_in, &pattern[i], action_type); + if (j >= max_actions) + return -EINVAL; + action_type = MLX5_GET(set_action_in, &pattern[i], action_type); hws_action_modify_get_target_fields(action_type, &pattern[i], &src_field, &dst_field); - if (i % 2) { - if (action_type == MLX5_ACTION_TYPE_COPY && - (prev_src_field == src_field || - prev_dst_field == dst_field)) { - /* need Nop */ - *new_size += 1; - *nop_locations |= BIT(i); - memset(&new_pat[j], 0, MLX5HWS_MODIFY_ACTION_SIZE); - MLX5_SET(set_action_in, &new_pat[j], - action_type, - MLX5_MODIFICATION_TYPE_NOP); - j++; - } else if (prev_src_field == src_field) { - /* need Nop */ - *new_size += 1; - *nop_locations |= BIT(i); - MLX5_SET(set_action_in, &new_pat[j], - action_type, - MLX5_MODIFICATION_TYPE_NOP); - j++; - } - } - memcpy(&new_pat[j], &pattern[i], MLX5HWS_MODIFY_ACTION_SIZE); - /* check if no more space */ - if (j > max_actions) { - *new_size = num_actions; - *nop_locations = 0; - return; + + /* For every action, look at it and the previous one. The two + * actions are dependent if: + */ + dependent = + (i > 0) && + /* At least one of the actions is a write and */ + (dst_field != INVALID_FIELD || + prev_dst_field != INVALID_FIELD) && + /* One reads from the other's source */ + (dst_field == prev_src_field || + src_field == prev_dst_field || + /* Or both write to the same destination */ + dst_field == prev_dst_field); + + if (dependent) { + *new_size += 1; + *nop_locations |= BIT(i); + memset(&new_pat[j], 0, MLX5HWS_MODIFY_ACTION_SIZE); + MLX5_SET(set_action_in, &new_pat[j], action_type, + MLX5_MODIFICATION_TYPE_NOP); + j++; + if (j >= max_actions) + return -EINVAL; } + memcpy(&new_pat[j], &pattern[i], MLX5HWS_MODIFY_ACTION_SIZE); prev_src_field = src_field; prev_dst_field = dst_field; } + + return 0; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.h b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.h index 91bd2572a341..7fbd8dc7aa18 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/steering/hws/pat_arg.h @@ -96,7 +96,7 @@ int mlx5hws_arg_write_inline_arg_data(struct mlx5hws_context *ctx, u8 *arg_data, size_t data_size); -void mlx5hws_pat_calc_nop(__be64 *pattern, size_t num_actions, - size_t max_actions, size_t *new_size, - u32 *nop_locations, __be64 *new_pat); +int mlx5hws_pat_calc_nop(__be64 *pattern, size_t num_actions, + size_t max_actions, size_t *new_size, + u32 *nop_locations, __be64 *new_pat); #endif /* MLX5HWS_PAT_ARG_H_ */