1 files changed, 332 insertions, 3 deletions

diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index 8330bc0bcb7e..c22897bf5509 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -19,6 +19,8 @@
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/slab.h>
+#include <net/netdev_queues.h>
+#include <net/page_pool/helpers.h>
 #include <net/netlink.h>
 #include <net/pkt_cls.h>
 #include <net/rtnetlink.h>
@@ -26,11 +28,33 @@
 
 #include "netdevsim.h"
 
+#define NSIM_RING_SIZE		256
+
+static int nsim_napi_rx(struct nsim_rq *rq, struct sk_buff *skb)
+{
+	if (skb_queue_len(&rq->skb_queue) > NSIM_RING_SIZE) {
+		dev_kfree_skb_any(skb);
+		return NET_RX_DROP;
+	}
+
+	skb_queue_tail(&rq->skb_queue, skb);
+	return NET_RX_SUCCESS;
+}
+
+static int nsim_forward_skb(struct net_device *dev, struct sk_buff *skb,
+			    struct nsim_rq *rq)
+{
+	return __dev_forward_skb(dev, skb) ?: nsim_napi_rx(rq, skb);
+}
+
 static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct netdevsim *ns = netdev_priv(dev);
+	struct net_device *peer_dev;
 	unsigned int len = skb->len;
 	struct netdevsim *peer_ns;
+	struct nsim_rq *rq;
+	int rxq;
 
 	rcu_read_lock();
 	if (!nsim_ipsec_tx(ns, skb))
@@ -40,10 +64,18 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (!peer_ns)
 		goto out_drop_free;
 
+	peer_dev = peer_ns->netdev;
+	rxq = skb_get_queue_mapping(skb);
+	if (rxq >= peer_dev->num_rx_queues)
+		rxq = rxq % peer_dev->num_rx_queues;
+	rq = &peer_ns->rq[rxq];
+
 	skb_tx_timestamp(skb);
-	if (unlikely(dev_forward_skb(peer_ns->netdev, skb) == NET_RX_DROP))
+	if (unlikely(nsim_forward_skb(peer_dev, skb, rq) == NET_RX_DROP))
 		goto out_drop_cnt;
 
+	napi_schedule(&rq->napi);
+
 	rcu_read_unlock();
 	u64_stats_update_begin(&ns->syncp);
 	ns->tx_packets++;
@@ -72,7 +104,7 @@ static int nsim_change_mtu(struct net_device *dev, int new_mtu)
 	if (ns->xdp.prog && new_mtu > NSIM_XDP_MAX_MTU)
 		return -EBUSY;
 
-	dev->mtu = new_mtu;
+	WRITE_ONCE(dev->mtu, new_mtu);
 
 	return 0;
 }
@@ -298,6 +330,150 @@ static int nsim_get_iflink(const struct net_device *dev)
 	return iflink;
 }
 
+static int nsim_rcv(struct nsim_rq *rq, int budget)
+{
+	struct sk_buff *skb;
+	int i;
+
+	for (i = 0; i < budget; i++) {
+		if (skb_queue_empty(&rq->skb_queue))
+			break;
+
+		skb = skb_dequeue(&rq->skb_queue);
+		netif_receive_skb(skb);
+	}
+
+	return i;
+}
+
+static int nsim_poll(struct napi_struct *napi, int budget)
+{
+	struct nsim_rq *rq = container_of(napi, struct nsim_rq, napi);
+	int done;
+
+	done = nsim_rcv(rq, budget);
+	napi_complete(napi);
+
+	return done;
+}
+
+static int nsim_create_page_pool(struct nsim_rq *rq)
+{
+	struct page_pool_params p = {
+		.order = 0,
+		.pool_size = NSIM_RING_SIZE,
+		.nid = NUMA_NO_NODE,
+		.dev = &rq->napi.dev->dev,
+		.napi = &rq->napi,
+		.dma_dir = DMA_BIDIRECTIONAL,
+		.netdev = rq->napi.dev,
+	};
+
+	rq->page_pool = page_pool_create(&p);
+	if (IS_ERR(rq->page_pool)) {
+		int err = PTR_ERR(rq->page_pool);
+
+		rq->page_pool = NULL;
+		return err;
+	}
+	return 0;
+}
+
+static int nsim_init_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	struct nsim_rq *rq;
+	int err, i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		rq = &ns->rq[i];
+
+		netif_napi_add(dev, &rq->napi, nsim_poll);
+	}
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		rq = &ns->rq[i];
+
+		err = nsim_create_page_pool(rq);
+		if (err)
+			goto err_pp_destroy;
+	}
+
+	return 0;
+
+err_pp_destroy:
+	while (i--) {
+		page_pool_destroy(ns->rq[i].page_pool);
+		ns->rq[i].page_pool = NULL;
+	}
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		__netif_napi_del(&ns->rq[i].napi);
+
+	return err;
+}
+
+static void nsim_enable_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		struct nsim_rq *rq = &ns->rq[i];
+
+		netif_queue_set_napi(dev, i, NETDEV_QUEUE_TYPE_RX, &rq->napi);
+		napi_enable(&rq->napi);
+	}
+}
+
+static int nsim_open(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+	int err;
+
+	err = nsim_init_napi(ns);
+	if (err)
+		return err;
+
+	nsim_enable_napi(ns);
+
+	return 0;
+}
+
+static void nsim_del_napi(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		struct nsim_rq *rq = &ns->rq[i];
+
+		napi_disable(&rq->napi);
+		__netif_napi_del(&rq->napi);
+	}
+	synchronize_net();
+
+	for (i = 0; i < dev->num_rx_queues; i++) {
+		page_pool_destroy(ns->rq[i].page_pool);
+		ns->rq[i].page_pool = NULL;
+	}
+}
+
+static int nsim_stop(struct net_device *dev)
+{
+	struct netdevsim *ns = netdev_priv(dev);
+	struct netdevsim *peer;
+
+	netif_carrier_off(dev);
+	peer = rtnl_dereference(ns->peer);
+	if (peer)
+		netif_carrier_off(peer->netdev);
+
+	nsim_del_napi(ns);
+
+	return 0;
+}
+
 static const struct net_device_ops nsim_netdev_ops = {
 	.ndo_start_xmit		= nsim_start_xmit,
 	.ndo_set_rx_mode	= nsim_set_rx_mode,
@@ -317,6 +493,8 @@ static const struct net_device_ops nsim_netdev_ops = {
 	.ndo_set_features	= nsim_set_features,
 	.ndo_get_iflink		= nsim_get_iflink,
 	.ndo_bpf		= nsim_bpf,
+	.ndo_open		= nsim_open,
+	.ndo_stop		= nsim_stop,
 };
 
 static const struct net_device_ops nsim_vf_netdev_ops = {
@@ -330,6 +508,107 @@ static const struct net_device_ops nsim_vf_netdev_ops = {
 	.ndo_set_features	= nsim_set_features,
 };
 
+/* We don't have true per-queue stats, yet, so do some random fakery here.
+ * Only report stuff for queue 0.
+ */
+static void nsim_get_queue_stats_rx(struct net_device *dev, int idx,
+				    struct netdev_queue_stats_rx *stats)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	if (!idx)
+		nsim_get_stats64(dev, &rtstats);
+
+	stats->packets = rtstats.rx_packets - !!rtstats.rx_packets;
+	stats->bytes = rtstats.rx_bytes;
+}
+
+static void nsim_get_queue_stats_tx(struct net_device *dev, int idx,
+				    struct netdev_queue_stats_tx *stats)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	if (!idx)
+		nsim_get_stats64(dev, &rtstats);
+
+	stats->packets = rtstats.tx_packets - !!rtstats.tx_packets;
+	stats->bytes = rtstats.tx_bytes;
+}
+
+static void nsim_get_base_stats(struct net_device *dev,
+				struct netdev_queue_stats_rx *rx,
+				struct netdev_queue_stats_tx *tx)
+{
+	struct rtnl_link_stats64 rtstats = {};
+
+	nsim_get_stats64(dev, &rtstats);
+
+	rx->packets = !!rtstats.rx_packets;
+	rx->bytes = 0;
+	tx->packets = !!rtstats.tx_packets;
+	tx->bytes = 0;
+}
+
+static const struct netdev_stat_ops nsim_stat_ops = {
+	.get_queue_stats_tx	= nsim_get_queue_stats_tx,
+	.get_queue_stats_rx	= nsim_get_queue_stats_rx,
+	.get_base_stats		= nsim_get_base_stats,
+};
+
+static ssize_t
+nsim_pp_hold_read(struct file *file, char __user *data,
+		  size_t count, loff_t *ppos)
+{
+	struct netdevsim *ns = file->private_data;
+	char buf[3] = "n\n";
+
+	if (ns->page)
+		buf[0] = 'y';
+
+	return simple_read_from_buffer(data, count, ppos, buf, 2);
+}
+
+static ssize_t
+nsim_pp_hold_write(struct file *file, const char __user *data,
+		   size_t count, loff_t *ppos)
+{
+	struct netdevsim *ns = file->private_data;
+	ssize_t ret;
+	bool val;
+
+	ret = kstrtobool_from_user(data, count, &val);
+	if (ret)
+		return ret;
+
+	rtnl_lock();
+	ret = count;
+	if (val == !!ns->page)
+		goto exit;
+
+	if (!netif_running(ns->netdev) && val) {
+		ret = -ENETDOWN;
+	} else if (val) {
+		ns->page = page_pool_dev_alloc_pages(ns->rq[0].page_pool);
+		if (!ns->page)
+			ret = -ENOMEM;
+	} else {
+		page_pool_put_full_page(ns->page->pp, ns->page, false);
+		ns->page = NULL;
+	}
+	rtnl_unlock();
+
+exit:
+	return count;
+}
+
+static const struct file_operations nsim_pp_hold_fops = {
+	.open = simple_open,
+	.read = nsim_pp_hold_read,
+	.write = nsim_pp_hold_write,
+	.llseek = generic_file_llseek,
+	.owner = THIS_MODULE,
+};
+
 static void nsim_setup(struct net_device *dev)
 {
 	ether_setup(dev);
@@ -349,6 +628,35 @@ static void nsim_setup(struct net_device *dev)
 	dev->xdp_features = NETDEV_XDP_ACT_HW_OFFLOAD;
 }
 
+static int nsim_queue_init(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	ns->rq = kvcalloc(dev->num_rx_queues, sizeof(*ns->rq),
+			  GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
+	if (!ns->rq)
+		return -ENOMEM;
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		skb_queue_head_init(&ns->rq[i].skb_queue);
+
+	return 0;
+}
+
+static void nsim_queue_free(struct netdevsim *ns)
+{
+	struct net_device *dev = ns->netdev;
+	int i;
+
+	for (i = 0; i < dev->num_rx_queues; i++)
+		skb_queue_purge_reason(&ns->rq[i].skb_queue,
+				       SKB_DROP_REASON_QUEUE_PURGE);
+
+	kvfree(ns->rq);
+	ns->rq = NULL;
+}
+
 static int nsim_init_netdevsim(struct netdevsim *ns)
 {
 	struct mock_phc *phc;
@@ -360,16 +668,21 @@ static int nsim_init_netdevsim(struct netdevsim *ns)
 
 	ns->phc = phc;
 	ns->netdev->netdev_ops = &nsim_netdev_ops;
+	ns->netdev->stat_ops = &nsim_stat_ops;
 
 	err = nsim_udp_tunnels_info_create(ns->nsim_dev, ns->netdev);
 	if (err)
 		goto err_phc_destroy;
 
 	rtnl_lock();
-	err = nsim_bpf_init(ns);
+	err = nsim_queue_init(ns);
 	if (err)
 		goto err_utn_destroy;
 
+	err = nsim_bpf_init(ns);
+	if (err)
+		goto err_rq_destroy;
+
 	nsim_macsec_init(ns);
 	nsim_ipsec_init(ns);
 
@@ -383,6 +696,8 @@ err_ipsec_teardown:
 	nsim_ipsec_teardown(ns);
 	nsim_macsec_teardown(ns);
 	nsim_bpf_uninit(ns);
+err_rq_destroy:
+	nsim_queue_free(ns);
 err_utn_destroy:
 	rtnl_unlock();
 	nsim_udp_tunnels_info_destroy(ns->netdev);
@@ -436,6 +751,10 @@ nsim_create(struct nsim_dev *nsim_dev, struct nsim_dev_port *nsim_dev_port)
 		err = nsim_init_netdevsim_vf(ns);
 	if (err)
 		goto err_free_netdev;
+
+	ns->pp_dfs = debugfs_create_file("pp_hold", 0600, nsim_dev_port->ddir,
+					 ns, &nsim_pp_hold_fops);
+
 	return ns;
 
 err_free_netdev:
@@ -448,6 +767,8 @@ void nsim_destroy(struct netdevsim *ns)
 	struct net_device *dev = ns->netdev;
 	struct netdevsim *peer;
 
+	debugfs_remove(ns->pp_dfs);
+
 	rtnl_lock();
 	peer = rtnl_dereference(ns->peer);
 	if (peer)
@@ -458,10 +779,18 @@ void nsim_destroy(struct netdevsim *ns)
 		nsim_macsec_teardown(ns);
 		nsim_ipsec_teardown(ns);
 		nsim_bpf_uninit(ns);
+		nsim_queue_free(ns);
 	}
 	rtnl_unlock();
 	if (nsim_dev_port_is_pf(ns->nsim_dev_port))
 		nsim_exit_netdevsim(ns);
+
+	/* Put this intentionally late to exercise the orphaning path */
+	if (ns->page) {
+		page_pool_put_full_page(ns->page->pp, ns->page, false);
+		ns->page = NULL;
+	}
+
 	free_netdev(dev);
 }