diff options
Diffstat (limited to 'net/core/netpoll.c')
| -rw-r--r-- | net/core/netpoll.c | 878 |
1 files changed, 878 insertions, 0 deletions
diff --git a/net/core/netpoll.c b/net/core/netpoll.c new file mode 100644 index 000000000..4ac8d0ad9 --- /dev/null +++ b/net/core/netpoll.c @@ -0,0 +1,878 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Common framework for low-level network console, dump, and debugger code + * + * Sep 8 2003 Matt Mackall <mpm@selenic.com> + * + * based on the netconsole code from: + * + * Copyright (C) 2001 Ingo Molnar <mingo@redhat.com> + * Copyright (C) 2002 Red Hat, Inc. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/moduleparam.h> +#include <linux/kernel.h> +#include <linux/netdevice.h> +#include <linux/etherdevice.h> +#include <linux/string.h> +#include <linux/if_arp.h> +#include <linux/inetdevice.h> +#include <linux/inet.h> +#include <linux/interrupt.h> +#include <linux/netpoll.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <linux/rcupdate.h> +#include <linux/workqueue.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <linux/if_vlan.h> +#include <net/tcp.h> +#include <net/udp.h> +#include <net/addrconf.h> +#include <net/ndisc.h> +#include <net/ip6_checksum.h> +#include <asm/unaligned.h> +#include <trace/events/napi.h> +#include <linux/kconfig.h> + +/* + * We maintain a small pool of fully-sized skbs, to make sure the + * message gets out even in extreme OOM situations. + */ + +#define MAX_UDP_CHUNK 1460 +#define MAX_SKBS 32 + +static struct sk_buff_head skb_pool; + +DEFINE_STATIC_SRCU(netpoll_srcu); + +#define USEC_PER_POLL 50 + +#define MAX_SKB_SIZE \ + (sizeof(struct ethhdr) + \ + sizeof(struct iphdr) + \ + sizeof(struct udphdr) + \ + MAX_UDP_CHUNK) + +static void zap_completion_queue(void); + +static unsigned int carrier_timeout = 4; +module_param(carrier_timeout, uint, 0644); + +#define np_info(np, fmt, ...) \ + pr_info("%s: " fmt, np->name, ##__VA_ARGS__) +#define np_err(np, fmt, ...) \ + pr_err("%s: " fmt, np->name, ##__VA_ARGS__) +#define np_notice(np, fmt, ...) \ + pr_notice("%s: " fmt, np->name, ##__VA_ARGS__) + +static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb, + struct net_device *dev, + struct netdev_queue *txq) +{ + netdev_tx_t status = NETDEV_TX_OK; + netdev_features_t features; + + features = netif_skb_features(skb); + + if (skb_vlan_tag_present(skb) && + !vlan_hw_offload_capable(features, skb->vlan_proto)) { + skb = __vlan_hwaccel_push_inside(skb); + if (unlikely(!skb)) { + /* This is actually a packet drop, but we + * don't want the code that calls this + * function to try and operate on a NULL skb. + */ + goto out; + } + } + + status = netdev_start_xmit(skb, dev, txq, false); + +out: + return status; +} + +static void queue_process(struct work_struct *work) +{ + struct netpoll_info *npinfo = + container_of(work, struct netpoll_info, tx_work.work); + struct sk_buff *skb; + unsigned long flags; + + while ((skb = skb_dequeue(&npinfo->txq))) { + struct net_device *dev = skb->dev; + struct netdev_queue *txq; + unsigned int q_index; + + if (!netif_device_present(dev) || !netif_running(dev)) { + kfree_skb(skb); + continue; + } + + local_irq_save(flags); + /* check if skb->queue_mapping is still valid */ + q_index = skb_get_queue_mapping(skb); + if (unlikely(q_index >= dev->real_num_tx_queues)) { + q_index = q_index % dev->real_num_tx_queues; + skb_set_queue_mapping(skb, q_index); + } + txq = netdev_get_tx_queue(dev, q_index); + HARD_TX_LOCK(dev, txq, smp_processor_id()); + if (netif_xmit_frozen_or_stopped(txq) || + !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) { + skb_queue_head(&npinfo->txq, skb); + HARD_TX_UNLOCK(dev, txq); + local_irq_restore(flags); + + schedule_delayed_work(&npinfo->tx_work, HZ/10); + return; + } + HARD_TX_UNLOCK(dev, txq); + local_irq_restore(flags); + } +} + +static int netif_local_xmit_active(struct net_device *dev) +{ + int i; + + for (i = 0; i < dev->num_tx_queues; i++) { + struct netdev_queue *txq = netdev_get_tx_queue(dev, i); + + if (READ_ONCE(txq->xmit_lock_owner) == smp_processor_id()) + return 1; + } + + return 0; +} + +static void poll_one_napi(struct napi_struct *napi) +{ + int work; + + /* If we set this bit but see that it has already been set, + * that indicates that napi has been disabled and we need + * to abort this operation + */ + if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state)) + return; + + /* We explicilty pass the polling call a budget of 0 to + * indicate that we are clearing the Tx path only. + */ + work = napi->poll(napi, 0); + WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll); + trace_napi_poll(napi, work, 0); + + clear_bit(NAPI_STATE_NPSVC, &napi->state); +} + +static void poll_napi(struct net_device *dev) +{ + struct napi_struct *napi; + int cpu = smp_processor_id(); + + list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { + if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) { + poll_one_napi(napi); + smp_store_release(&napi->poll_owner, -1); + } + } +} + +void netpoll_poll_dev(struct net_device *dev) +{ + struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo); + const struct net_device_ops *ops; + + /* Don't do any rx activity if the dev_lock mutex is held + * the dev_open/close paths use this to block netpoll activity + * while changing device state + */ + if (!ni || down_trylock(&ni->dev_lock)) + return; + + /* Some drivers will take the same locks in poll and xmit, + * we can't poll if local CPU is already in xmit. + */ + if (!netif_running(dev) || netif_local_xmit_active(dev)) { + up(&ni->dev_lock); + return; + } + + ops = dev->netdev_ops; + if (ops->ndo_poll_controller) + ops->ndo_poll_controller(dev); + + poll_napi(dev); + + up(&ni->dev_lock); + + zap_completion_queue(); +} +EXPORT_SYMBOL(netpoll_poll_dev); + +void netpoll_poll_disable(struct net_device *dev) +{ + struct netpoll_info *ni; + int idx; + might_sleep(); + idx = srcu_read_lock(&netpoll_srcu); + ni = srcu_dereference(dev->npinfo, &netpoll_srcu); + if (ni) + down(&ni->dev_lock); + srcu_read_unlock(&netpoll_srcu, idx); +} +EXPORT_SYMBOL(netpoll_poll_disable); + +void netpoll_poll_enable(struct net_device *dev) +{ + struct netpoll_info *ni; + rcu_read_lock(); + ni = rcu_dereference(dev->npinfo); + if (ni) + up(&ni->dev_lock); + rcu_read_unlock(); +} +EXPORT_SYMBOL(netpoll_poll_enable); + +static void refill_skbs(void) +{ + struct sk_buff *skb; + unsigned long flags; + + spin_lock_irqsave(&skb_pool.lock, flags); + while (skb_pool.qlen < MAX_SKBS) { + skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); + if (!skb) + break; + + __skb_queue_tail(&skb_pool, skb); + } + spin_unlock_irqrestore(&skb_pool.lock, flags); +} + +static void zap_completion_queue(void) +{ + unsigned long flags; + struct softnet_data *sd = &get_cpu_var(softnet_data); + + if (sd->completion_queue) { + struct sk_buff *clist; + + local_irq_save(flags); + clist = sd->completion_queue; + sd->completion_queue = NULL; + local_irq_restore(flags); + + while (clist != NULL) { + struct sk_buff *skb = clist; + clist = clist->next; + if (!skb_irq_freeable(skb)) { + refcount_set(&skb->users, 1); + dev_kfree_skb_any(skb); /* put this one back */ + } else { + __kfree_skb(skb); + } + } + } + + put_cpu_var(softnet_data); +} + +static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) +{ + int count = 0; + struct sk_buff *skb; + + zap_completion_queue(); + refill_skbs(); +repeat: + + skb = alloc_skb(len, GFP_ATOMIC); + if (!skb) + skb = skb_dequeue(&skb_pool); + + if (!skb) { + if (++count < 10) { + netpoll_poll_dev(np->dev); + goto repeat; + } + return NULL; + } + + refcount_set(&skb->users, 1); + skb_reserve(skb, reserve); + return skb; +} + +static int netpoll_owner_active(struct net_device *dev) +{ + struct napi_struct *napi; + + list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) { + if (napi->poll_owner == smp_processor_id()) + return 1; + } + return 0; +} + +/* call with IRQ disabled */ +static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) +{ + netdev_tx_t status = NETDEV_TX_BUSY; + struct net_device *dev; + unsigned long tries; + /* It is up to the caller to keep npinfo alive. */ + struct netpoll_info *npinfo; + + lockdep_assert_irqs_disabled(); + + dev = np->dev; + npinfo = rcu_dereference_bh(dev->npinfo); + + if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) { + dev_kfree_skb_irq(skb); + return NET_XMIT_DROP; + } + + /* don't get messages out of order, and no recursion */ + if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) { + struct netdev_queue *txq; + + txq = netdev_core_pick_tx(dev, skb, NULL); + + /* try until next clock tick */ + for (tries = jiffies_to_usecs(1)/USEC_PER_POLL; + tries > 0; --tries) { + if (HARD_TX_TRYLOCK(dev, txq)) { + if (!netif_xmit_stopped(txq)) + status = netpoll_start_xmit(skb, dev, txq); + + HARD_TX_UNLOCK(dev, txq); + + if (dev_xmit_complete(status)) + break; + + } + + /* tickle device maybe there is some cleanup */ + netpoll_poll_dev(np->dev); + + udelay(USEC_PER_POLL); + } + + WARN_ONCE(!irqs_disabled(), + "netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n", + dev->name, dev->netdev_ops->ndo_start_xmit); + + } + + if (!dev_xmit_complete(status)) { + skb_queue_tail(&npinfo->txq, skb); + schedule_delayed_work(&npinfo->tx_work,0); + } + return NETDEV_TX_OK; +} + +netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) +{ + unsigned long flags; + netdev_tx_t ret; + + if (unlikely(!np)) { + dev_kfree_skb_irq(skb); + ret = NET_XMIT_DROP; + } else { + local_irq_save(flags); + ret = __netpoll_send_skb(np, skb); + local_irq_restore(flags); + } + return ret; +} +EXPORT_SYMBOL(netpoll_send_skb); + +void netpoll_send_udp(struct netpoll *np, const char *msg, int len) +{ + int total_len, ip_len, udp_len; + struct sk_buff *skb; + struct udphdr *udph; + struct iphdr *iph; + struct ethhdr *eth; + static atomic_t ip_ident; + struct ipv6hdr *ip6h; + + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) + WARN_ON_ONCE(!irqs_disabled()); + + udp_len = len + sizeof(*udph); + if (np->ipv6) + ip_len = udp_len + sizeof(*ip6h); + else + ip_len = udp_len + sizeof(*iph); + + total_len = ip_len + LL_RESERVED_SPACE(np->dev); + + skb = find_skb(np, total_len + np->dev->needed_tailroom, + total_len - len); + if (!skb) + return; + + skb_copy_to_linear_data(skb, msg, len); + skb_put(skb, len); + + skb_push(skb, sizeof(*udph)); + skb_reset_transport_header(skb); + udph = udp_hdr(skb); + udph->source = htons(np->local_port); + udph->dest = htons(np->remote_port); + udph->len = htons(udp_len); + + if (np->ipv6) { + udph->check = 0; + udph->check = csum_ipv6_magic(&np->local_ip.in6, + &np->remote_ip.in6, + udp_len, IPPROTO_UDP, + csum_partial(udph, udp_len, 0)); + if (udph->check == 0) + udph->check = CSUM_MANGLED_0; + + skb_push(skb, sizeof(*ip6h)); + skb_reset_network_header(skb); + ip6h = ipv6_hdr(skb); + + /* ip6h->version = 6; ip6h->priority = 0; */ + *(unsigned char *)ip6h = 0x60; + ip6h->flow_lbl[0] = 0; + ip6h->flow_lbl[1] = 0; + ip6h->flow_lbl[2] = 0; + + ip6h->payload_len = htons(sizeof(struct udphdr) + len); + ip6h->nexthdr = IPPROTO_UDP; + ip6h->hop_limit = 32; + ip6h->saddr = np->local_ip.in6; + ip6h->daddr = np->remote_ip.in6; + + eth = skb_push(skb, ETH_HLEN); + skb_reset_mac_header(skb); + skb->protocol = eth->h_proto = htons(ETH_P_IPV6); + } else { + udph->check = 0; + udph->check = csum_tcpudp_magic(np->local_ip.ip, + np->remote_ip.ip, + udp_len, IPPROTO_UDP, + csum_partial(udph, udp_len, 0)); + if (udph->check == 0) + udph->check = CSUM_MANGLED_0; + + skb_push(skb, sizeof(*iph)); + skb_reset_network_header(skb); + iph = ip_hdr(skb); + + /* iph->version = 4; iph->ihl = 5; */ + *(unsigned char *)iph = 0x45; + iph->tos = 0; + put_unaligned(htons(ip_len), &(iph->tot_len)); + iph->id = htons(atomic_inc_return(&ip_ident)); + iph->frag_off = 0; + iph->ttl = 64; + iph->protocol = IPPROTO_UDP; + iph->check = 0; + put_unaligned(np->local_ip.ip, &(iph->saddr)); + put_unaligned(np->remote_ip.ip, &(iph->daddr)); + iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); + + eth = skb_push(skb, ETH_HLEN); + skb_reset_mac_header(skb); + skb->protocol = eth->h_proto = htons(ETH_P_IP); + } + + ether_addr_copy(eth->h_source, np->dev->dev_addr); + ether_addr_copy(eth->h_dest, np->remote_mac); + + skb->dev = np->dev; + + netpoll_send_skb(np, skb); +} +EXPORT_SYMBOL(netpoll_send_udp); + +void netpoll_print_options(struct netpoll *np) +{ + np_info(np, "local port %d\n", np->local_port); + if (np->ipv6) + np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6); + else + np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip); + np_info(np, "interface '%s'\n", np->dev_name); + np_info(np, "remote port %d\n", np->remote_port); + if (np->ipv6) + np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6); + else + np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip); + np_info(np, "remote ethernet address %pM\n", np->remote_mac); +} +EXPORT_SYMBOL(netpoll_print_options); + +static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr) +{ + const char *end; + + if (!strchr(str, ':') && + in4_pton(str, -1, (void *)addr, -1, &end) > 0) { + if (!*end) + return 0; + } + if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) { +#if IS_ENABLED(CONFIG_IPV6) + if (!*end) + return 1; +#else + return -1; +#endif + } + return -1; +} + +int netpoll_parse_options(struct netpoll *np, char *opt) +{ + char *cur=opt, *delim; + int ipv6; + bool ipversion_set = false; + + if (*cur != '@') { + if ((delim = strchr(cur, '@')) == NULL) + goto parse_failed; + *delim = 0; + if (kstrtou16(cur, 10, &np->local_port)) + goto parse_failed; + cur = delim; + } + cur++; + + if (*cur != '/') { + ipversion_set = true; + if ((delim = strchr(cur, '/')) == NULL) + goto parse_failed; + *delim = 0; + ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip); + if (ipv6 < 0) + goto parse_failed; + else + np->ipv6 = (bool)ipv6; + cur = delim; + } + cur++; + + if (*cur != ',') { + /* parse out dev name */ + if ((delim = strchr(cur, ',')) == NULL) + goto parse_failed; + *delim = 0; + strscpy(np->dev_name, cur, sizeof(np->dev_name)); + cur = delim; + } + cur++; + + if (*cur != '@') { + /* dst port */ + if ((delim = strchr(cur, '@')) == NULL) + goto parse_failed; + *delim = 0; + if (*cur == ' ' || *cur == '\t') + np_info(np, "warning: whitespace is not allowed\n"); + if (kstrtou16(cur, 10, &np->remote_port)) + goto parse_failed; + cur = delim; + } + cur++; + + /* dst ip */ + if ((delim = strchr(cur, '/')) == NULL) + goto parse_failed; + *delim = 0; + ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip); + if (ipv6 < 0) + goto parse_failed; + else if (ipversion_set && np->ipv6 != (bool)ipv6) + goto parse_failed; + else + np->ipv6 = (bool)ipv6; + cur = delim + 1; + + if (*cur != 0) { + /* MAC address */ + if (!mac_pton(cur, np->remote_mac)) + goto parse_failed; + } + + netpoll_print_options(np); + + return 0; + + parse_failed: + np_info(np, "couldn't parse config at '%s'!\n", cur); + return -1; +} +EXPORT_SYMBOL(netpoll_parse_options); + +int __netpoll_setup(struct netpoll *np, struct net_device *ndev) +{ + struct netpoll_info *npinfo; + const struct net_device_ops *ops; + int err; + + np->dev = ndev; + strscpy(np->dev_name, ndev->name, IFNAMSIZ); + + if (ndev->priv_flags & IFF_DISABLE_NETPOLL) { + np_err(np, "%s doesn't support polling, aborting\n", + np->dev_name); + err = -ENOTSUPP; + goto out; + } + + if (!ndev->npinfo) { + npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL); + if (!npinfo) { + err = -ENOMEM; + goto out; + } + + sema_init(&npinfo->dev_lock, 1); + skb_queue_head_init(&npinfo->txq); + INIT_DELAYED_WORK(&npinfo->tx_work, queue_process); + + refcount_set(&npinfo->refcnt, 1); + + ops = np->dev->netdev_ops; + if (ops->ndo_netpoll_setup) { + err = ops->ndo_netpoll_setup(ndev, npinfo); + if (err) + goto free_npinfo; + } + } else { + npinfo = rtnl_dereference(ndev->npinfo); + refcount_inc(&npinfo->refcnt); + } + + npinfo->netpoll = np; + + /* last thing to do is link it to the net device structure */ + rcu_assign_pointer(ndev->npinfo, npinfo); + + return 0; + +free_npinfo: + kfree(npinfo); +out: + return err; +} +EXPORT_SYMBOL_GPL(__netpoll_setup); + +int netpoll_setup(struct netpoll *np) +{ + struct net_device *ndev = NULL; + struct in_device *in_dev; + int err; + + rtnl_lock(); + if (np->dev_name[0]) { + struct net *net = current->nsproxy->net_ns; + ndev = __dev_get_by_name(net, np->dev_name); + } + if (!ndev) { + np_err(np, "%s doesn't exist, aborting\n", np->dev_name); + err = -ENODEV; + goto unlock; + } + dev_hold(ndev); + + if (netdev_master_upper_dev_get(ndev)) { + np_err(np, "%s is a slave device, aborting\n", np->dev_name); + err = -EBUSY; + goto put; + } + + if (!netif_running(ndev)) { + unsigned long atmost, atleast; + + np_info(np, "device %s not up yet, forcing it\n", np->dev_name); + + err = dev_open(ndev, NULL); + + if (err) { + np_err(np, "failed to open %s\n", ndev->name); + goto put; + } + + rtnl_unlock(); + atleast = jiffies + HZ/10; + atmost = jiffies + carrier_timeout * HZ; + while (!netif_carrier_ok(ndev)) { + if (time_after(jiffies, atmost)) { + np_notice(np, "timeout waiting for carrier\n"); + break; + } + msleep(1); + } + + /* If carrier appears to come up instantly, we don't + * trust it and pause so that we don't pump all our + * queued console messages into the bitbucket. + */ + + if (time_before(jiffies, atleast)) { + np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n"); + msleep(4000); + } + rtnl_lock(); + } + + if (!np->local_ip.ip) { + if (!np->ipv6) { + const struct in_ifaddr *ifa; + + in_dev = __in_dev_get_rtnl(ndev); + if (!in_dev) + goto put_noaddr; + + ifa = rtnl_dereference(in_dev->ifa_list); + if (!ifa) { +put_noaddr: + np_err(np, "no IP address for %s, aborting\n", + np->dev_name); + err = -EDESTADDRREQ; + goto put; + } + + np->local_ip.ip = ifa->ifa_local; + np_info(np, "local IP %pI4\n", &np->local_ip.ip); + } else { +#if IS_ENABLED(CONFIG_IPV6) + struct inet6_dev *idev; + + err = -EDESTADDRREQ; + idev = __in6_dev_get(ndev); + if (idev) { + struct inet6_ifaddr *ifp; + + read_lock_bh(&idev->lock); + list_for_each_entry(ifp, &idev->addr_list, if_list) { + if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) != + !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL)) + continue; + np->local_ip.in6 = ifp->addr; + err = 0; + break; + } + read_unlock_bh(&idev->lock); + } + if (err) { + np_err(np, "no IPv6 address for %s, aborting\n", + np->dev_name); + goto put; + } else + np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6); +#else + np_err(np, "IPv6 is not supported %s, aborting\n", + np->dev_name); + err = -EINVAL; + goto put; +#endif + } + } + + /* fill up the skb queue */ + refill_skbs(); + + err = __netpoll_setup(np, ndev); + if (err) + goto put; + netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL); + rtnl_unlock(); + return 0; + +put: + dev_put(ndev); +unlock: + rtnl_unlock(); + return err; +} +EXPORT_SYMBOL(netpoll_setup); + +static int __init netpoll_init(void) +{ + skb_queue_head_init(&skb_pool); + return 0; +} +core_initcall(netpoll_init); + +static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) +{ + struct netpoll_info *npinfo = + container_of(rcu_head, struct netpoll_info, rcu); + + skb_queue_purge(&npinfo->txq); + + /* we can't call cancel_delayed_work_sync here, as we are in softirq */ + cancel_delayed_work(&npinfo->tx_work); + + /* clean after last, unfinished work */ + __skb_queue_purge(&npinfo->txq); + /* now cancel it again */ + cancel_delayed_work(&npinfo->tx_work); + kfree(npinfo); +} + +void __netpoll_cleanup(struct netpoll *np) +{ + struct netpoll_info *npinfo; + + npinfo = rtnl_dereference(np->dev->npinfo); + if (!npinfo) + return; + + synchronize_srcu(&netpoll_srcu); + + if (refcount_dec_and_test(&npinfo->refcnt)) { + const struct net_device_ops *ops; + + ops = np->dev->netdev_ops; + if (ops->ndo_netpoll_cleanup) + ops->ndo_netpoll_cleanup(np->dev); + + RCU_INIT_POINTER(np->dev->npinfo, NULL); + call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info); + } else + RCU_INIT_POINTER(np->dev->npinfo, NULL); +} +EXPORT_SYMBOL_GPL(__netpoll_cleanup); + +void __netpoll_free(struct netpoll *np) +{ + ASSERT_RTNL(); + + /* Wait for transmitting packets to finish before freeing. */ + synchronize_rcu(); + __netpoll_cleanup(np); + kfree(np); +} +EXPORT_SYMBOL_GPL(__netpoll_free); + +void netpoll_cleanup(struct netpoll *np) +{ + rtnl_lock(); + if (!np->dev) + goto out; + __netpoll_cleanup(np); + netdev_put(np->dev, &np->dev_tracker); + np->dev = NULL; +out: + rtnl_unlock(); +} +EXPORT_SYMBOL(netpoll_cleanup); |