net/mlx5: SF, Handle function changed event

When host is powered off, firmware does not send vhca_state event
for every probed host SF on the DPU because it may have deployed
thousands of SFs to the host. Instead it sends a function changed
event. Currently, only VFs handle this event. This commit extends
support to SFs.

When DPU user deactivates[1] SFs, mlx5 expects vhca_state event
and leaves the SF in dangling state[2].

When DPU user deletes[3] SFs, mlx5 also expects vhca_state event
and destroys the SF resources[4].

Fix it by changing SF to the right state and freeing SF resources
when the function changed event is received.

When this event is received, driver checks all SF states.
 - If state is in_use, change it to active.
 - If state is teardown_request, change it to allocated.

And SF hardware table entry is freed if it is pending for delete.

[1]
 # devlink port function set en3f0c1pf0sf0 state inactive

[2]
 # devlink port function set en3f0c1pf0sf0 state active
 Error: mlx5_core: SF is inactivated but it is still attached.
 kernel answers: Device or resource busy

[3]
 # devlink port show
 pci/0000:03:00.0/229376: type eth netdev en3f0c1pf0sf0 \
	flavour pcisf controller 1 pfnum 0 sfnum 0 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state active opstate attached \
	roce enable trust off max_uc_macs 4096 max_io_eqs 8
 # devlink port del en3f0c1pf0sf0

[4]
 # devlink port add pci/0000:03:00.0 flavour pcisf pfnum 0 sfnum 0 \
	controller 1
 Error: mlx5_core: SF already exist. Choose different sfnum.
 kernel answers: File exists

Fixes: 6a32732174 ("net/mlx5: SF, Port function state change support")
Signed-off-by: Chris Mi <cmi@nvidia.com>
Reviewed-by: Shay Drori <shayd@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260729071622.2423270-1-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -3986,7 +3986,7 @@ 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)
+static void esw_changed_event_handler(struct mlx5_eswitch *esw)
 {
 	struct mlx5_esw_pf_info host_pf_info;
 	u16 new_num_vfs;
@@ -3999,6 +3999,11 @@ static void esw_vfs_changed_event_handler(struct mlx5_eswitch *esw)
 	host_pf_info = mlx5_esw_get_host_pf_info(esw->dev, out);
 	new_num_vfs = host_pf_info.num_of_vfs;
 
+	if (host_pf_info.pf_disabled) {
+		mlx5_sf_table_esw_changed_event_handler(esw->dev);
+		mlx5_sf_hw_table_esw_changed_event_handler(esw->dev);
+	}
+
 	if (new_num_vfs == esw->esw_funcs.num_vfs || host_pf_info.pf_disabled)
 		goto free;
 
@@ -4091,8 +4096,7 @@ int mlx5_esw_funcs_changed_handler(struct notifier_block *nb,
 	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,
-				GFP_ATOMIC);
+	ret = mlx5_esw_add_work(esw, esw_changed_event_handler, GFP_ATOMIC);
 	if (ret)
 		return NOTIFY_DONE;
 

drivers/net/ethernet/mellanox/mlx5/core/sf/devlink.c

@@ -561,3 +561,32 @@ bool mlx5_sf_table_empty(const struct mlx5_core_dev *dev)
 
 	return xa_empty(&table->function_ids);
 }
+
+void mlx5_sf_table_esw_changed_event_handler(struct mlx5_core_dev *dev)
+{
+	struct mlx5_sf_table *table = dev->priv.sf_table;
+	unsigned long index;
+	struct mlx5_sf *sf;
+
+	trace_mlx5_sf_host_pf_disabled(dev);
+
+	if (!table)
+		return;
+
+	mutex_lock(&table->sf_state_lock);
+	xa_for_each(&table->function_ids, index, sf) {
+		if (!sf->controller)
+			continue;
+
+		if (sf->hw_state == MLX5_VHCA_STATE_IN_USE)
+			sf->hw_state = MLX5_VHCA_STATE_ACTIVE;
+		else if (sf->hw_state == MLX5_VHCA_STATE_TEARDOWN_REQUEST)
+			sf->hw_state = MLX5_VHCA_STATE_ALLOCATED;
+		else
+			continue;
+		trace_mlx5_sf_update_state(table->dev, sf->port_index,
+					   sf->controller, sf->hw_fn_id,
+					   sf->hw_state);
+	}
+	mutex_unlock(&table->sf_state_lock);
+}

drivers/net/ethernet/mellanox/mlx5/core/sf/diag/sf_tracepoint.h

@@ -11,6 +11,14 @@
 #include <linux/mlx5/driver.h>
 #include "sf/vhca_event.h"
 
+TRACE_EVENT(mlx5_sf_host_pf_disabled,
+	    TP_PROTO(const struct mlx5_core_dev *dev),
+	    TP_ARGS(dev),
+	    TP_STRUCT__entry(__string(devname, dev_name(dev->device))),
+	    TP_fast_assign(__assign_str(devname);),
+	    TP_printk("(%s)\n", __get_str(devname))
+);
+
 TRACE_EVENT(mlx5_sf_add,
 	    TP_PROTO(const struct mlx5_core_dev *dev,
 		     unsigned int port_index,

drivers/net/ethernet/mellanox/mlx5/core/sf/hw_table.c

@@ -459,3 +459,25 @@ bool mlx5_sf_hw_table_supported(const struct mlx5_core_dev *dev)
 {
 	return !!dev->priv.sf_hw_table;
 }
+
+void mlx5_sf_hw_table_esw_changed_event_handler(struct mlx5_core_dev *dev)
+{
+	struct mlx5_sf_hw_table *table;
+	struct mlx5_sf_hwc_table *hwc;
+	int i;
+
+	table = dev->priv.sf_hw_table;
+	if (!table)
+		return;
+
+	mutex_lock(&table->table_lock);
+	hwc = &table->hwc[MLX5_SF_HWC_EXT_HOST];
+	for (i = 0; i < hwc->max_fn; i++) {
+		struct mlx5_sf_hw *sf_hw;
+
+		sf_hw = &hwc->sfs[i];
+		if (sf_hw->allocated && sf_hw->pending_delete)
+			mlx5_sf_hw_table_hwc_sf_free(dev, hwc, i);
+	}
+	mutex_unlock(&table->table_lock);
+}

drivers/net/ethernet/mellanox/mlx5/core/sf/sf.h

@@ -15,12 +15,14 @@ void mlx5_sf_hw_table_cleanup(struct mlx5_core_dev *dev);
 int mlx5_sf_hw_notifier_init(struct mlx5_core_dev *dev);
 void mlx5_sf_hw_notifier_cleanup(struct mlx5_core_dev *dev);
 void mlx5_sf_hw_table_destroy(struct mlx5_core_dev *dev);
+void mlx5_sf_hw_table_esw_changed_event_handler(struct mlx5_core_dev *dev);
 
 int mlx5_sf_notifiers_init(struct mlx5_core_dev *dev);
 int mlx5_sf_table_init(struct mlx5_core_dev *dev);
 void mlx5_sf_notifiers_cleanup(struct mlx5_core_dev *dev);
 void mlx5_sf_table_cleanup(struct mlx5_core_dev *dev);
 bool mlx5_sf_table_empty(const struct mlx5_core_dev *dev);
+void mlx5_sf_table_esw_changed_event_handler(struct mlx5_core_dev *dev);
 
 int mlx5_devlink_sf_port_new(struct devlink *devlink,
 			     const struct devlink_port_new_attrs *add_attr,
@@ -60,6 +62,11 @@ static inline void mlx5_sf_hw_table_destroy(struct mlx5_core_dev *dev)
 {
 }
 
+static inline void
+mlx5_sf_hw_table_esw_changed_event_handler(struct mlx5_core_dev *dev)
+{
+}
+
 static inline int mlx5_sf_notifiers_init(struct mlx5_core_dev *dev)
 {
 	return 0;
@@ -83,6 +90,11 @@ static inline bool mlx5_sf_table_empty(const struct mlx5_core_dev *dev)
 	return true;
 }
 
+static inline void
+mlx5_sf_table_esw_changed_event_handler(struct mlx5_core_dev *dev)
+{
+}
+
 #endif
 
 #endif