[PATCH net-next 3/7] net/mlx5: E-Switch, introduce generic work queue dispatch helper

Tariq Toukan
2026-04-09T11:57:09Z

From: Mark Bloch <mbloch@nvidia.com>

Each E-Switch work item requires the same boilerplate: acquire the
devlink lock, check whether the work is stale, dispatch to the
appropriate handler, and release the lock. Factor this out.

Add a func callback to mlx5_host_work so the generic handler
esw_wq_handler() can dispatch to the right function without
duplicating locking logic. Introduce mlx5_esw_add_work() as the
single enqueue point: it stamps the work item with the current
generation counter and queues it onto the E-Switch work queue.

Refactor esw_vfs_changed_event_handler() to match the new contract:
it no longer receives work_gen or out as parameters. It queries
mlx5_esw_query_functions() itself and owns the kvfree() of the
result. The devlink lock is acquired and released by esw_wq_handler()
before dispatching, so the handler runs with the lock already held.

Update mlx5_esw_funcs_changed_handler() to use mlx5_esw_add_work().

Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
.../net/ethernet/mellanox/mlx5/core/eswitch.h | 1 +
.../mellanox/mlx5/core/eswitch_offloads.c | 77 +++++++++++--------
2 files changed, 45 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index 0c3d2bdebf8c..e3ab8a30c174 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -336,6 +336,7 @@ struct mlx5_host_work {
struct work_struct work;
struct mlx5_eswitch *esw;
int work_gen;
+ void (*func)(struct mlx5_eswitch *esw);
};

struct mlx5_esw_functions {
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
index b2e7294d3a5c..23af5a12dc07 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c
@@ -3655,20 +3655,15 @@ static void esw_offloads_steering_cleanup(struct mlx5_eswitch *esw)
mutex_destroy(&esw->fdb_table.offloads.vports.lock);
}

-static void
-esw_vfs_changed_event_handler(struct mlx5_eswitch *esw, int work_gen,
- const u32 *out)
+static void esw_vfs_changed_event_handler(struct mlx5_eswitch *esw)
{
- struct devlink *devlink;
bool host_pf_disabled;
u16 new_num_vfs;
+ const u32 *out;

- devlink = priv_to_devlink(esw->dev);
- devl_lock(devlink);
-
- /* Stale work from one or more mode changes ago. Bail out. */
- if (work_gen != atomic_read(&esw->generation))
- goto unlock;
+ out = mlx5_esw_query_functions(esw->dev);
+ if (IS_ERR(out))
+ return;

new_num_vfs = MLX5_GET(query_esw_functions_out, out,
host_params_context.host_num_of_vfs);
@@ -3676,7 +3671,7 @@ esw_vfs_changed_event_handler(struct mlx5_eswitch *esw, int work_gen,
host_params_context.host_pf_disabled);

if (new_num_vfs == esw->esw_funcs.num_vfs || host_pf_disabled)
- goto unlock;
+ goto free;

/* Number of VFs can only change from "0 to x" or "x to 0". */
if (esw->esw_funcs.num_vfs > 0) {
@@ -3686,54 +3681,70 @@ esw_vfs_changed_event_handler(struct mlx5_eswitch *esw, int work_gen,

err = mlx5_eswitch_load_vf_vports(esw, new_num_vfs,
MLX5_VPORT_UC_ADDR_CHANGE);
- if (err) {
- devl_unlock(devlink);
- return;
- }
+ if (err)
+ goto free;
}
esw->esw_funcs.num_vfs = new_num_vfs;
-unlock:
- devl_unlock(devlink);
+free:
+ kvfree(out);
}

-static void esw_functions_changed_event_handler(struct work_struct *work)
+static void esw_wq_handler(struct work_struct *work)
{
struct mlx5_host_work *host_work;
struct mlx5_eswitch *esw;
- const u32 *out;
+ struct devlink *devlink;

host_work = container_of(work, struct mlx5_host_work, work);
esw = host_work->esw;
+ devlink = priv_to_devlink(esw->dev);

- out = mlx5_esw_query_functions(esw->dev);
- if (IS_ERR(out))
- goto out;
+ devl_lock(devlink);

- esw_vfs_changed_event_handler(esw, host_work->work_gen, out);
- kvfree(out);
-out:
+ /* Stale work from one or more mode changes ago. Bail out. */
+ if (host_work->work_gen != atomic_read(&esw->generation))
+ goto unlock;
+
+ host_work->func(esw);
+
+unlock:
+ devl_unlock(devlink);
kfree(host_work);
}

-int mlx5_esw_funcs_changed_handler(struct notifier_block *nb, unsigned long type, void *data)
+static int mlx5_esw_add_work(struct mlx5_eswitch *esw,
+ void (*func)(struct mlx5_eswitch *esw))
{
- struct mlx5_esw_functions *esw_funcs;
struct mlx5_host_work *host_work;
- struct mlx5_eswitch *esw;

host_work = kzalloc_obj(*host_work, GFP_ATOMIC);
if (!host_work)
- return NOTIFY_DONE;
-
- esw_funcs = mlx5_nb_cof(nb, struct mlx5_esw_functions, nb);
- esw = container_of(esw_funcs, struct mlx5_eswitch, esw_funcs);
+ return -ENOMEM;

host_work->esw = esw;
host_work->work_gen = atomic_read(&esw->generation);

- INIT_WORK(&host_work->work, esw_functions_changed_event_handler);
+ host_work->func = func;
+ INIT_WORK(&host_work->work, esw_wq_handler);
queue_work(esw->work_queue, &host_work->work);

+ return 0;
+}
+
+int mlx5_esw_funcs_changed_handler(struct notifier_block *nb,
+ unsigned long type, void *data)
+{
+ struct mlx5_esw_functions *esw_funcs;
+ struct mlx5_eswitch *esw;
+ int ret;
+
+ esw_funcs = mlx5_nb_cof(nb, struct mlx5_esw_functions, nb);
+ esw = container_of(esw_funcs, struct mlx5_eswitch, esw_funcs);
+
+ ret = mlx5_esw_add_work(esw, esw_vfs_changed_event_handler);
+ if (ret)
+ return NOTIFY_DONE;
+
return NOTIFY_OK;
}

--
2.44.0