net/mlx5: Add HV VHCA control agent

Control agent is responsible over of the control block (ID 0). It should
update the PF via this block about every capability change. In addition,
upon block 0 invalidate, it should activate all other supported agents
with data requests from the PF.

Upon agent create/destroy, the invalidate callback of the control agent
is being called in order to update the PF driver about this change.

The control agent is an integral part of HV VHCA and will be created
and destroy as part of the HV VHCA init/cleanup flow.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.c

@@ -109,22 +109,131 @@ void mlx5_hv_vhca_invalidate(void *context, u64 block_mask)
 	queue_work(hv_vhca->work_queue, &work->invalidate_work);
 }
 
+#define AGENT_MASK(type) (type ? BIT(type - 1) : 0 /* control */)
+
+static void mlx5_hv_vhca_agents_control(struct mlx5_hv_vhca *hv_vhca,
+					struct mlx5_hv_vhca_control_block *block)
+{
+	int i;
+
+	for (i = 0; i < MLX5_HV_VHCA_AGENT_MAX; i++) {
+		struct mlx5_hv_vhca_agent *agent = hv_vhca->agents[i];
+
+		if (!agent || !agent->control)
+			continue;
+
+		if (!(AGENT_MASK(agent->type) & block->control))
+			continue;
+
+		agent->control(agent, block);
+	}
+}
+
+static void mlx5_hv_vhca_capabilities(struct mlx5_hv_vhca *hv_vhca,
+				      u32 *capabilities)
+{
+	int i;
+
+	for (i = 0; i < MLX5_HV_VHCA_AGENT_MAX; i++) {
+		struct mlx5_hv_vhca_agent *agent = hv_vhca->agents[i];
+
+		if (agent)
+			*capabilities |= AGENT_MASK(agent->type);
+	}
+}
+
+static void
+mlx5_hv_vhca_control_agent_invalidate(struct mlx5_hv_vhca_agent *agent,
+				      u64 block_mask)
+{
+	struct mlx5_hv_vhca *hv_vhca = agent->hv_vhca;
+	struct mlx5_core_dev *dev = hv_vhca->dev;
+	struct mlx5_hv_vhca_control_block *block;
+	u32 capabilities = 0;
+	int err;
+
+	block = kzalloc(sizeof(*block), GFP_KERNEL);
+	if (!block)
+		return;
+
+	err = mlx5_hv_read_config(dev, block, sizeof(*block), 0);
+	if (err)
+		goto free_block;
+
+	mlx5_hv_vhca_capabilities(hv_vhca, &capabilities);
+
+	/* In case no capabilities, send empty block in return */
+	if (!capabilities) {
+		memset(block, 0, sizeof(*block));
+		goto write;
+	}
+
+	if (block->capabilities != capabilities)
+		block->capabilities = capabilities;
+
+	if (block->control & ~capabilities)
+		goto free_block;
+
+	mlx5_hv_vhca_agents_control(hv_vhca, block);
+	block->command_ack = block->command;
+
+write:
+	mlx5_hv_write_config(dev, block, sizeof(*block), 0);
+
+free_block:
+	kfree(block);
+}
+
+static struct mlx5_hv_vhca_agent *
+mlx5_hv_vhca_control_agent_create(struct mlx5_hv_vhca *hv_vhca)
+{
+	return mlx5_hv_vhca_agent_create(hv_vhca, MLX5_HV_VHCA_AGENT_CONTROL,
+					 NULL,
+					 mlx5_hv_vhca_control_agent_invalidate,
+					 NULL, NULL);
+}
+
+static void mlx5_hv_vhca_control_agent_destroy(struct mlx5_hv_vhca_agent *agent)
+{
+	mlx5_hv_vhca_agent_destroy(agent);
+}
+
 int mlx5_hv_vhca_init(struct mlx5_hv_vhca *hv_vhca)
 {
+	struct mlx5_hv_vhca_agent *agent;
+	int err;
+
 	if (IS_ERR_OR_NULL(hv_vhca))
 		return IS_ERR_OR_NULL(hv_vhca);
 
-	return mlx5_hv_register_invalidate(hv_vhca->dev, hv_vhca,
+	err = mlx5_hv_register_invalidate(hv_vhca->dev, hv_vhca,
 					  mlx5_hv_vhca_invalidate);
+	if (err)
+		return err;
+
+	agent = mlx5_hv_vhca_control_agent_create(hv_vhca);
+	if (IS_ERR_OR_NULL(agent)) {
+		mlx5_hv_unregister_invalidate(hv_vhca->dev);
+		return IS_ERR_OR_NULL(agent);
+	}
+
+	hv_vhca->agents[MLX5_HV_VHCA_AGENT_CONTROL] = agent;
+
+	return 0;
 }
 
 void mlx5_hv_vhca_cleanup(struct mlx5_hv_vhca *hv_vhca)
 {
+	struct mlx5_hv_vhca_agent *agent;
 	int i;
 
 	if (IS_ERR_OR_NULL(hv_vhca))
 		return;
 
+	agent = hv_vhca->agents[MLX5_HV_VHCA_AGENT_CONTROL];
+	if (agent)
+		mlx5_hv_vhca_control_agent_destroy(agent);
+
 	mutex_lock(&hv_vhca->agents_lock);
 	for (i = 0; i < MLX5_HV_VHCA_AGENT_MAX; i++)
 		WARN_ON(hv_vhca->agents[i]);
@@ -134,6 +243,11 @@ void mlx5_hv_vhca_cleanup(struct mlx5_hv_vhca *hv_vhca)
 	mlx5_hv_unregister_invalidate(hv_vhca->dev);
 }
 
+static void mlx5_hv_vhca_agents_update(struct mlx5_hv_vhca *hv_vhca)
+{
+	mlx5_hv_vhca_invalidate(hv_vhca, BIT(MLX5_HV_VHCA_AGENT_CONTROL));
+}
+
 struct mlx5_hv_vhca_agent *
 mlx5_hv_vhca_agent_create(struct mlx5_hv_vhca *hv_vhca,
 			  enum mlx5_hv_vhca_agent_type type,
@@ -174,6 +288,8 @@ mlx5_hv_vhca_agent_create(struct mlx5_hv_vhca *hv_vhca,
 	hv_vhca->agents[type] = agent;
 	mutex_unlock(&hv_vhca->agents_lock);
 
+	mlx5_hv_vhca_agents_update(hv_vhca);
+
 	return agent;
 }
 
@@ -195,6 +311,8 @@ void mlx5_hv_vhca_agent_destroy(struct mlx5_hv_vhca_agent *agent)
 		agent->cleanup(agent);
 
 	kfree(agent);
+
+	mlx5_hv_vhca_agents_update(hv_vhca);
 }
 
 static int mlx5_hv_vhca_data_block_prepare(struct mlx5_hv_vhca_agent *agent,

drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.h

@@ -12,6 +12,7 @@ struct mlx5_hv_vhca;
 struct mlx5_hv_vhca_control_block;
 
 enum mlx5_hv_vhca_agent_type {
+	MLX5_HV_VHCA_AGENT_CONTROL = 0,
 	MLX5_HV_VHCA_AGENT_MAX = 32,
 };