[PATCH net-next v2 3/3] net: drop rtnl_lock for queue_mgmt operations

[Stanislav Fomichev]

All drivers that use queue API are already converted to use
netdev instance lock. Move netdev instance lock management to
the netlink layer and drop rtnl_lock.

Cc: Mina Almasry <almasrymina@xxxxxxxxxx>
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c |  4 ++--
 drivers/net/netdevsim/netdev.c            |  4 ++--
 net/core/devmem.c                         |  4 ++--
 net/core/netdev-genl.c                    | 13 ++++++-------
 net/core/netdev_rx_queue.c                | 16 ++++++----------
 5 files changed, 18 insertions(+), 23 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index b09171110ec4..fed08aaf68e4 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -11381,14 +11381,14 @@ static void bnxt_irq_affinity_notify(struct irq_affinity_notify *notify,
 	if (pcie_tph_set_st_entry(irq->bp->pdev, irq->msix_nr, tag))
 		return;
 
-	rtnl_lock();
+	netdev_lock(irq->bp->dev);
 	if (netif_running(irq->bp->dev)) {
 		err = netdev_rx_queue_restart(irq->bp->dev, irq->ring_nr);
 		if (err)
 			netdev_err(irq->bp->dev,
 				   "RX queue restart failed: err=%d\n", err);
 	}
-	rtnl_unlock();
+	netdev_unlock(irq->bp->dev);
 }
 
 static void bnxt_irq_affinity_release(struct kref *ref)
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index d71fd2907cc8..e3152ebe98a2 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -787,7 +787,7 @@ nsim_qreset_write(struct file *file, const char __user *data,
 	if (ret != 2)
 		return -EINVAL;
 
-	rtnl_lock();
+	netdev_lock(ns->netdev);
 	if (queue >= ns->netdev->real_num_rx_queues) {
 		ret = -EINVAL;
 		goto exit_unlock;
@@ -801,7 +801,7 @@ nsim_qreset_write(struct file *file, const char __user *data,
 
 	ret = count;
 exit_unlock:
-	rtnl_unlock();
+	netdev_unlock(ns->netdev);
 	return ret;
 }
 
diff --git a/net/core/devmem.c b/net/core/devmem.c
index 7c6e0b5b6acb..5c4d79a1bcd8 100644
--- a/net/core/devmem.c
+++ b/net/core/devmem.c
@@ -25,7 +25,6 @@
 
 /* Device memory support */
 
-/* Protected by rtnl_lock() */
 static DEFINE_XARRAY_FLAGS(net_devmem_dmabuf_bindings, XA_FLAGS_ALLOC1);
 
 static const struct memory_provider_ops dmabuf_devmem_ops;
@@ -128,9 +127,10 @@ void net_devmem_unbind_dmabuf(struct net_devmem_dmabuf_binding *binding)
 		rxq->mp_params.mp_priv = NULL;
 		rxq->mp_params.mp_ops = NULL;
 
+		netdev_lock(binding->dev);
 		rxq_idx = get_netdev_rx_queue_index(rxq);
-
 		WARN_ON(netdev_rx_queue_restart(binding->dev, rxq_idx));
+		netdev_unlock(binding->dev);
 	}
 
 	xa_erase(&net_devmem_dmabuf_bindings, binding->id);
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 63e10717efc5..a186fea63c09 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -860,12 +860,11 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	mutex_lock(&priv->lock);
-	rtnl_lock();
 
-	netdev = __dev_get_by_index(genl_info_net(info), ifindex);
+	netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex);
 	if (!netdev || !netif_device_present(netdev)) {
 		err = -ENODEV;
-		goto err_unlock;
+		goto err_unlock_sock;
 	}
 
 	if (dev_xdp_prog_count(netdev)) {
@@ -918,7 +917,8 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
 	if (err)
 		goto err_unbind;
 
-	rtnl_unlock();
+	netdev_unlock(netdev);
+
 	mutex_unlock(&priv->lock);
 
 	return 0;
@@ -926,7 +926,8 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
 err_unbind:
 	net_devmem_unbind_dmabuf(binding);
 err_unlock:
-	rtnl_unlock();
+	netdev_unlock(netdev);
+err_unlock_sock:
 	mutex_unlock(&priv->lock);
 err_genlmsg_free:
 	nlmsg_free(rsp);
@@ -946,9 +947,7 @@ void netdev_nl_sock_priv_destroy(struct netdev_nl_sock *priv)
 
 	mutex_lock(&priv->lock);
 	list_for_each_entry_safe(binding, temp, &priv->bindings, list) {
-		rtnl_lock();
 		net_devmem_unbind_dmabuf(binding);
-		rtnl_unlock();
 	}
 	mutex_unlock(&priv->lock);
 }
diff --git a/net/core/netdev_rx_queue.c b/net/core/netdev_rx_queue.c
index 7419c41fd3cb..a5b234b33cd5 100644
--- a/net/core/netdev_rx_queue.c
+++ b/net/core/netdev_rx_queue.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <linux/netdevice.h>
+#include <net/netdev_lock.h>
 #include <net/netdev_queues.h>
 #include <net/netdev_rx_queue.h>
 #include <net/page_pool/memory_provider.h>
@@ -18,7 +19,7 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
 	    !qops->ndo_queue_mem_alloc || !qops->ndo_queue_start)
 		return -EOPNOTSUPP;
 
-	ASSERT_RTNL();
+	netdev_assert_locked(dev);
 
 	new_mem = kvzalloc(qops->ndo_queue_mem_size, GFP_KERNEL);
 	if (!new_mem)
@@ -30,8 +31,6 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
 		goto err_free_new_mem;
 	}
 
-	netdev_lock(dev);
-
 	err = qops->ndo_queue_mem_alloc(dev, new_mem, rxq_idx);
 	if (err)
 		goto err_free_old_mem;
@@ -54,8 +53,6 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
 
 	qops->ndo_queue_mem_free(dev, old_mem);
 
-	netdev_unlock(dev);
-
 	kvfree(old_mem);
 	kvfree(new_mem);
 
@@ -80,7 +77,6 @@ int netdev_rx_queue_restart(struct net_device *dev, unsigned int rxq_idx)
 	qops->ndo_queue_mem_free(dev, new_mem);
 
 err_free_old_mem:
-	netdev_unlock(dev);
 	kvfree(old_mem);
 
 err_free_new_mem:
@@ -118,9 +114,9 @@ int net_mp_open_rxq(struct net_device *dev, unsigned ifq_idx,
 {
 	int ret;
 
-	rtnl_lock();
+	netdev_lock(dev);
 	ret = __net_mp_open_rxq(dev, ifq_idx, p);
-	rtnl_unlock();
+	netdev_unlock(dev);
 	return ret;
 }
 
@@ -153,7 +149,7 @@ static void __net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
 void net_mp_close_rxq(struct net_device *dev, unsigned ifq_idx,
 		      struct pp_memory_provider_params *old_p)
 {
-	rtnl_lock();
+	netdev_lock(dev);
 	__net_mp_close_rxq(dev, ifq_idx, old_p);
-	rtnl_unlock();
+	netdev_unlock(dev);
 }
-- 
2.48.1