queue_api: define queue api

This API enables the net stack to reset the queues used for devmem TCP.

Signed-off-by: Mina Almasry <almasrymina@google.com>
Signed-off-by: Shailend Chand <shailend@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: mina

include/linux/netdevice.h

@@ -1957,6 +1957,7 @@ enum netdev_reg_state {
  *	@sysfs_rx_queue_group:	Space for optional per-rx queue attributes
  *	@rtnl_link_ops:	Rtnl_link_ops
  *	@stat_ops:	Optional ops for queue-aware statistics
+ *	@queue_mgmt_ops:	Optional ops for queue management
  *
  *	@gso_max_size:	Maximum size of generic segmentation offload
  *	@tso_max_size:	Device (as in HW) limit on the max TSO request size
@@ -2340,6 +2341,8 @@ struct net_device {
 
 	const struct netdev_stat_ops *stat_ops;
 
+	const struct netdev_queue_mgmt_ops *queue_mgmt_ops;
+
 	/* for setting kernel sock attribute on TCP connection setup */
 #define GSO_MAX_SEGS		65535u
 #define GSO_LEGACY_MAX_SIZE	65536u

include/net/netdev_queues.h

@@ -87,6 +87,37 @@ struct netdev_stat_ops {
 			       struct netdev_queue_stats_tx *tx);
 };
 
+/**
+ * struct netdev_queue_mgmt_ops - netdev ops for queue management
+ *
+ * @ndo_queue_mem_size: Size of the struct that describes a queue's memory.
+ *
+ * @ndo_queue_mem_alloc: Allocate memory for an RX queue at the specified index.
+ *			 The new memory is written at the specified address.
+ *
+ * @ndo_queue_mem_free:	Free memory from an RX queue.
+ *
+ * @ndo_queue_start:	Start an RX queue with the specified memory and at the
+ *			specified index.
+ *
+ * @ndo_queue_stop:	Stop the RX queue at the specified index. The stopped
+ *			queue's memory is written at the specified address.
+ */
+struct netdev_queue_mgmt_ops {
+	size_t			ndo_queue_mem_size;
+	int			(*ndo_queue_mem_alloc)(struct net_device *dev,
+						       void *per_queue_mem,
+						       int idx);
+	void			(*ndo_queue_mem_free)(struct net_device *dev,
+						      void *per_queue_mem);
+	int			(*ndo_queue_start)(struct net_device *dev,
+						   void *per_queue_mem,
+						   int idx);
+	int			(*ndo_queue_stop)(struct net_device *dev,
+						  void *per_queue_mem,
+						  int idx);
+};
+
 /**
  * DOC: Lockless queue stopping / waking helpers.
  *