Merge branch 'introduce-queue-and-napi-support-in-netdev-genl-was-introduce-napi-queues-support'

Amritha Nambiar says:

====================
Introduce queue and NAPI support in netdev-genl (Was: Introduce NAPI queues support)

Add the capability to export the following via netdev-genl interface:
- queue information supported by the device
- NAPI information supported by the device

Introduce support for associating queue and NAPI instance.
Extend the netdev_genl generic netlink family for netdev
with queue and NAPI data.

The queue parameters exposed are:
- queue index
- queue type
- ifindex
- NAPI id associated with the queue

Additional rx and tx queue parameters can be exposed in follow up
patches by stashing them in netdev queue structures. XDP queue type
can also be supported in future.

The NAPI fields exposed are:
- NAPI id
- NAPI device ifindex
- Interrupt number associated with the NAPI instance
- PID for the NAPI thread

This series only supports 'get' ability for retrieving
certain queue and NAPI attributes. The 'set' ability for
configuring queue and associated NAPI instance via netdev-genl
will be submitted as a separate patch series.

Previous discussion at:
https://lore.kernel.org/netdev/c8476530638a5f4381d64db0e024ed49c2db3b02.camel@gmail.com/T/#m00999652a8b4731fbdb7bf698d2e3666c65a60e7

$ ./cli.py --spec netdev.yaml --do queue-get  --json='{"ifindex": 12, "id": 0, "type": 0}'
{'id': 0, 'ifindex': 12, 'napi-id': 593, 'type': 'rx'}

$ ./cli.py --spec netdev.yaml  --do queue-get --json='{"ifindex": 12, "id": 0, "type": 1}'
{'id': 0, 'ifindex': 12, 'napi-id': 593, 'type': 'tx'}

$ ./cli.py --spec netdev.yaml  --dump queue-get --json='{"ifindex": 12}'
[{'id': 0, 'ifindex': 12, 'napi-id': 593, 'type': 'rx'},
 {'id': 1, 'ifindex': 12, 'napi-id': 594, 'type': 'rx'},
 {'id': 2, 'ifindex': 12, 'napi-id': 595, 'type': 'rx'},
 {'id': 3, 'ifindex': 12, 'napi-id': 596, 'type': 'rx'},
 {'id': 0, 'ifindex': 12, 'napi-id': 593, 'type': 'tx'},
 {'id': 1, 'ifindex': 12, 'napi-id': 594, 'type': 'tx'},
 {'id': 2, 'ifindex': 12, 'napi-id': 595, 'type': 'tx'},
 {'id': 3, 'ifindex': 12, 'napi-id': 596, 'type': 'tx'}]

$ ./cli.py --spec netdev.yaml --do napi-get --json='{"id": 593}'
{'id': 593, 'ifindex': 12, 'irq': 291, 'pid': 3727}

$ ./cli.py --spec netdev.yaml --dump napi-get --json='{"ifindex": 12}'
[{'id': 596, 'ifindex': 12, 'irq': 294, 'pid': 3724},
 {'id': 595, 'ifindex': 12, 'irq': 293, 'pid': 3725},
 {'id': 594, 'ifindex': 12, 'irq': 292, 'pid': 3726},
 {'id': 593, 'ifindex': 12, 'irq': 291, 'pid': 3727}]
====================

Link: https://lore.kernel.org/r/170147307026.5260.9300080745237900261.stgit@anambiarhost.jf.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 39 insertions, 2 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 3950ced396b5..1d720fc59161 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -165,7 +165,6 @@ static int netif_rx_internal(struct sk_buff *skb);
 static int call_netdevice_notifiers_extack(unsigned long val,
 					   struct net_device *dev,
 					   struct netlink_ext_ack *extack);
-static struct napi_struct *napi_by_id(unsigned int napi_id);
 
 /*
  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
@@ -6139,7 +6138,7 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
 EXPORT_SYMBOL(napi_complete_done);
 
 /* must be called under rcu_read_lock(), as we dont take a reference */
-static struct napi_struct *napi_by_id(unsigned int napi_id)
+struct napi_struct *napi_by_id(unsigned int napi_id)
 {
 	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
 	struct napi_struct *napi;
@@ -6400,6 +6399,43 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
 }
 EXPORT_SYMBOL(dev_set_threaded);
 
+/**
+ * netif_queue_set_napi - Associate queue with the napi
+ * @dev: device to which NAPI and queue belong
+ * @queue_index: Index of queue
+ * @type: queue type as RX or TX
+ * @napi: NAPI context, pass NULL to clear previously set NAPI
+ *
+ * Set queue with its corresponding napi context. This should be done after
+ * registering the NAPI handler for the queue-vector and the queues have been
+ * mapped to the corresponding interrupt vector.
+ */
+void netif_queue_set_napi(struct net_device *dev, unsigned int queue_index,
+			  enum netdev_queue_type type, struct napi_struct *napi)
+{
+	struct netdev_rx_queue *rxq;
+	struct netdev_queue *txq;
+
+	if (WARN_ON_ONCE(napi && !napi->dev))
+		return;
+	if (dev->reg_state >= NETREG_REGISTERED)
+		ASSERT_RTNL();
+
+	switch (type) {
+	case NETDEV_QUEUE_TYPE_RX:
+		rxq = __netif_get_rx_queue(dev, queue_index);
+		rxq->napi = napi;
+		return;
+	case NETDEV_QUEUE_TYPE_TX:
+		txq = netdev_get_tx_queue(dev, queue_index);
+		txq->napi = napi;
+		return;
+	default:
+		return;
+	}
+}
+EXPORT_SYMBOL(netif_queue_set_napi);
+
 void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
 			   int (*poll)(struct napi_struct *, int), int weight)
 {
@@ -6435,6 +6471,7 @@ void netif_napi_add_weight(struct net_device *dev, struct napi_struct *napi,
 	 */
 	if (dev->threaded && napi_kthread_create(napi))
 		dev->threaded = 0;
+	netif_napi_set_irq(napi, -1);
 }
 EXPORT_SYMBOL(netif_napi_add_weight);