[PATCH net-next 04/13] net/mlx5: LAG, allocate port-indexed scratch buffers dynamically
flat view
COOLING13d
IN NET-NEXT: 2 (0M)
From: Tariq Toukan <tariqt@nvidia.com>
Date: 2026-09-23 10:40:43
Also in:
linux-rdma, lkml
Subsystem:
mellanox mlx5 core vpi driver, networking drivers, the rest · Maintainers:
Saeed Mahameed, Leon Romanovsky, Tariq Toukan, Mark Bloch, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
2 review trailers; queued in net-next as 4138820bddda on 2026-09-29.
From: Shay Drory <redacted> mlx5_lag_print_mapping(), mlx5_infer_tx_affinity_mapping() and lag_active_port_bits() each used a MLX5_MAX_PORTS-sized stack buffer to hold per-port working state. Allocate these buffers with kcalloc(ldev->ports, ...) instead so they track the actual port count and no longer depend on MLX5_MAX_PORTS. lag_active_port_bits() can now fail on allocation, so it returns int and propagates -ENOMEM; a non-negative return is the active-port bitmask as before. Its two callers, mlx5_cmd_create_lag() and _mlx5_modify_lag(), check for a negative return and bail out, then narrow the value back into the u8 they hand to the device. This removes these buffers' dependency on MLX5_MAX_PORTS. Signed-off-by: Shay Drory <redacted> Reviewed-by: Moshe Shemesh <redacted> Reviewed-by: Akiva Goldberger <redacted> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> --- .../net/ethernet/mellanox/mlx5/core/lag/lag.c | 100 ++++++++++++++---- 1 file changed, 80 insertions(+), 20 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
index 00b0159cb422..93ead5664152 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/lag.c@@ -63,19 +63,25 @@ static int get_port_sel_mode(enum mlx5_lag_mode mode, unsigned long flags) return MLX5_LAG_PORT_SELECT_MODE_QUEUE_AFFINITY; } -static u8 lag_active_port_bits(struct mlx5_lag *ldev, - struct lag_tracker *tracker) +static int lag_active_port_bits(struct mlx5_lag *ldev, + struct lag_tracker *tracker) { - u8 enabled_ports[MLX5_MAX_PORTS] = {}; u8 active_port = 0; + u8 *enabled_ports; int num_enabled; int idx; + enabled_ports = kcalloc(ldev->ports, sizeof(*enabled_ports), + GFP_KERNEL); + if (!enabled_ports) + return -ENOMEM; + mlx5_infer_tx_enabled(tracker, ldev, enabled_ports, &num_enabled); for (idx = 0; idx < num_enabled; idx++) active_port |= BIT_MASK(enabled_ports[idx]); + kfree(enabled_ports); return active_port; }
@@ -105,13 +111,21 @@ static int mlx5_cmd_create_lag(struct mlx5_core_dev *dev, struct mlx5_lag *ldev, MLX5_SET(lagc, lag_ctx, tx_remap_affinity_1, ports[idx0]); MLX5_SET(lagc, lag_ctx, tx_remap_affinity_2, ports[idx1]); break; - case MLX5_LAG_PORT_SELECT_MODE_PORT_SELECT_FT: + case MLX5_LAG_PORT_SELECT_MODE_PORT_SELECT_FT: { + u8 active_port; + int ret; + if (!MLX5_CAP_PORT_SELECTION(dev, port_select_flow_table_bypass)) break; - MLX5_SET(lagc, lag_ctx, active_port, - lag_active_port_bits(ldev, tracker)); + ret = lag_active_port_bits(ldev, tracker); + if (ret < 0) + return ret; + + active_port = ret; + MLX5_SET(lagc, lag_ctx, active_port, active_port); break; + } default: break; }
@@ -240,22 +254,31 @@ static void mlx5_lag_print_mapping(struct mlx5_core_dev *dev, struct lag_tracker *tracker, unsigned long flags) { - char buf[MLX5_MAX_PORTS * 10 + 1] = {}; - u8 enabled_ports[MLX5_MAX_PORTS] = {}; + u8 *enabled_ports = NULL; int written = 0; int num_enabled; + char *buf; int idx; int err; int i; int j; + buf = kcalloc(ldev->ports * 10 + 1, sizeof(*buf), GFP_KERNEL); + if (!buf) + return; + if (test_bit(MLX5_LAG_MODE_FLAG_HASH_BASED, &flags)) { + enabled_ports = kcalloc(ldev->ports, sizeof(*enabled_ports), + GFP_KERNEL); + if (!enabled_ports) + goto free_buf; + mlx5_infer_tx_enabled(tracker, ldev, enabled_ports, &num_enabled); for (i = 0; i < num_enabled; i++) { err = scnprintf(buf + written, 4, "%d, ", enabled_ports[i] + 1); if (err != 3) - return; + goto free_enabled; written += err; } buf[written - 2] = 0;
@@ -267,12 +290,17 @@ static void mlx5_lag_print_mapping(struct mlx5_core_dev *dev, err = scnprintf(buf + written, 10, " port %d:%d", i + 1, ldev->v2p_map[idx]); if (err != 9) - return; + goto free_enabled; written += err; } } mlx5_core_info(dev, "lag map:%s\n", buf); } + +free_enabled: + kfree(enabled_ports); +free_buf: + kfree(buf); } static int mlx5_lag_netdev_event(struct notifier_block *this,
@@ -668,20 +696,28 @@ static bool __mlx5_lag_is_sd_active(struct mlx5_lag *ldev, * If there are ports that are disabled fill the relevant slots * with mapping that points to active ports. */ -static void mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker, - struct mlx5_lag *ldev, - u8 buckets, - u8 *ports) +static int mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker, + struct mlx5_lag *ldev, + u8 buckets, + u8 *ports) { - int disabled[MLX5_MAX_PORTS] = {}; - int enabled[MLX5_MAX_PORTS] = {}; int disabled_ports_num = 0; int enabled_ports_num = 0; + int *disabled; + int *enabled; + int err = 0; int idx; u32 rand; int i; int j; + enabled = kcalloc(ldev->ports, sizeof(*enabled), GFP_KERNEL); + disabled = kcalloc(ldev->ports, sizeof(*disabled), GFP_KERNEL); + if (!enabled || !disabled) { + err = -ENOMEM; + goto out; + } + mlx5_ldev_for_each(i, 0, ldev) { if (tracker->netdev_state[i].tx_enabled && tracker->netdev_state[i].link_up)
@@ -704,7 +740,7 @@ static void mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker, /* If all ports are disabled/enabled keep native mapping */ if (enabled_ports_num == ldev->ports || disabled_ports_num == ldev->ports) - return; + goto out; /* Go over the disabled ports and for each assign a random active port */ for (i = 0; i < disabled_ports_num; i++) {
@@ -717,6 +753,11 @@ static void mlx5_infer_tx_affinity_mapping(struct lag_tracker *tracker, mlx5_lag_xa_to_dev_idx(ldev, rand_xa_idx) + 1; } } + +out: + kfree(enabled); + kfree(disabled); + return err; } static bool mlx5_lag_has_drop_rule(struct mlx5_lag *ldev)
@@ -816,7 +857,10 @@ static int _mlx5_modify_lag(struct mlx5_lag *ldev, !MLX5_CAP_PORT_SELECTION(dev0, port_select_flow_table_bypass)) return ret; - active_ports = lag_active_port_bits(ldev, tracker); + ret = lag_active_port_bits(ldev, tracker); + if (ret < 0) + return ret; + active_ports = ret; return mlx5_cmd_modify_active_port(dev0, active_ports); }
@@ -879,7 +923,14 @@ void mlx5_modify_lag(struct mlx5_lag *ldev, if (!ports) return; - mlx5_infer_tx_affinity_mapping(tracker, ldev, ldev->buckets, ports); + err = mlx5_infer_tx_affinity_mapping(tracker, ldev, ldev->buckets, + ports); + if (err) { + mlx5_core_err(dev0, + "mlx5_infer_tx_affinity_mapping failed, err = %d\n", + err); + goto out; + } mlx5_ldev_for_each(i, 0, ldev) { for (j = 0; j < ldev->buckets; j++) {
@@ -1045,7 +1096,16 @@ int mlx5_activate_lag(struct mlx5_lag *ldev, return err; if (mode != MLX5_LAG_MODE_MPESW) { - mlx5_infer_tx_affinity_mapping(tracker, ldev, ldev->buckets, ldev->v2p_map); + err = mlx5_infer_tx_affinity_mapping(tracker, ldev, + ldev->buckets, + ldev->v2p_map); + if (err) { + mlx5_core_err(dev0, + "mlx5_infer_tx_affinity_mapping failed, err = %d\n", + err); + return err; + } + if (test_bit(MLX5_LAG_MODE_FLAG_HASH_BASED, &flags)) { err = mlx5_lag_port_sel_create(ldev, tracker->hash_type, ldev->v2p_map);
--
2.44.0