[PATCH net-next v11 10/21] net: add helpers for setting a memory provider on an rx queue

[David Wei <dw@davidwei.uk>]

Add helpers that properly prep or remove a memory provider for an rx
queue then restart the queue.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
---
 include/net/page_pool/memory_provider.h |  5 ++
 net/core/netdev_rx_queue.c              | 66 +++++++++++++++++++++++++
 2 files changed, 71 insertions(+)

diff --git a/include/net/page_pool/memory_provider.h b/include/net/page_pool/memory_provider.h
index 4f0ffb8f6a0a..b3e665897767 100644
--- a/include/net/page_pool/memory_provider.h
+++ b/include/net/page_pool/memory_provider.h
@@ -22,6 +22,11 @@ bool net_mp_niov_set_dma_addr(struct net_iov *niov, dma_addr_t addr);
 void net_mp_niov_set_page_pool(struct page_pool *pool, struct net_iov *niov);
 void net_mp_niov_clear_page_pool(struct net_iov *niov);
 
+int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
+		    struct pp_memory_provider_params *p);
+void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
+		      struct pp_memory_provider_params *old_p);
+
 /**
   * net_mp_netmem_place_in_cache() - give a netmem to a page pool
   * @pool:      the page pool to place the netmem into
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
index e217a5838c87..e934568d4cd9 100644
--- a/net/core/netdev_rx_queue.c
+++ b/net/core/netdev_rx_queue.c
@@ -3,6 +3,7 @@
 #include <linux/netdevice.h>
 #include <net/netdev_queues.h>
 #include <net/netdev_rx_queue.h>
+#include <net/page_pool/memory_provider.h>
 
 #include "page_pool_priv.h"
 
@@ -79,3 +80,68 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
 
 	return err;
 }
+
+static int __net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
+			     struct pp_memory_provider_params *p)
+{
+	struct netdev_rx_queue *rxq;
+	int ret;
+
+	if (ifq_idx >= dev->real_num_rx_queues)
+		return -EINVAL;
+	ifq_idx = array_index_nospec(ifq_idx, dev->real_num_rx_queues);
+
+	rxq = __netif_get_rx_queue(dev, ifq_idx);
+	if (rxq->mp_params.mp_ops)
+		return -EEXIST;
+
+	rxq->mp_params = *p;
+	ret = netdev_rx_queue_restart(dev, ifq_idx);
+	if (ret) {
+		rxq->mp_params.mp_ops = NULL;
+		rxq->mp_params.mp_priv = NULL;
+	}
+	return ret;
+}
+
+int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
+		    struct pp_memory_provider_params *p)
+{
+	int ret;
+
+	rtnl_lock();
+	ret = __net_mp_open_rxq(dev, ifq_idx, p);
+	rtnl_unlock();
+	return ret;
+}
+
+static void __net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
+			      struct pp_memory_provider_params *old_p)
+{
+	struct netdev_rx_queue *rxq;
+	int ret;
+
+	if (WARN_ON_ONCE(ifq_idx >= dev->real_num_rx_queues))
+		return;
+
+	rxq = __netif_get_rx_queue(dev, ifq_idx);
+
+	if (WARN_ON_ONCE(rxq->mp_params.mp_ops != old_p->mp_ops ||
+			 rxq->mp_params.mp_priv != old_p->mp_priv))
+		return;
+
+	rxq->mp_params.mp_ops = NULL;
+	rxq->mp_params.mp_priv = NULL;
+	ret = netdev_rx_queue_restart(dev, ifq_idx);
+	if (ret)
+		pr_devel("Could not restart queue %u after removing memory provider.\n",
+			 ifq_idx);
+}
+
+void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
+		      struct pp_memory_provider_params *old_p)
+{
+	rtnl_lock();
+	__net_mp_close_rxq(dev, ifq_idx, old_p);
+	rtnl_unlock();
+}
-- 
2.43.5