#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 <net/tcp.h>
#include <net/udp.h>
+#include <asm/unaligned.h>
/*
* We maintain a small pool of fully-sized skbs, to make sure the
* message gets out even in extreme OOM situations.
*/
-#define MAX_SKBS 32
#define MAX_UDP_CHUNK 1460
+#define MAX_SKBS 32
+#define MAX_QUEUE_DEPTH (MAX_SKBS / 2)
+#define MAX_RETRIES 20000
-static spinlock_t skb_list_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(skb_list_lock);
static int nr_skbs;
static struct sk_buff *skbs;
-static spinlock_t rx_list_lock = SPIN_LOCK_UNLOCKED;
-static LIST_HEAD(rx_list);
+static DEFINE_SPINLOCK(queue_lock);
+static int queue_depth;
+static struct sk_buff *queue_head, *queue_tail;
+
+static atomic_t trapped;
-static int trapped;
+#define NETPOLL_RX_ENABLED 1
+#define NETPOLL_RX_DROP 2
#define MAX_SKB_SIZE \
(MAX_UDP_CHUNK + sizeof(struct udphdr) + \
static void zap_completion_queue(void);
+static void queue_process(void *p)
+{
+ unsigned long flags;
+ struct sk_buff *skb;
+
+ while (queue_head) {
+ spin_lock_irqsave(&queue_lock, flags);
+
+ skb = queue_head;
+ queue_head = skb->next;
+ if (skb == queue_tail)
+ queue_head = NULL;
+
+ queue_depth--;
+
+ spin_unlock_irqrestore(&queue_lock, flags);
+
+ dev_queue_xmit(skb);
+ }
+}
+
+static DECLARE_WORK(send_queue, queue_process, NULL);
+
+void netpoll_queue(struct sk_buff *skb)
+{
+ unsigned long flags;
+
+ if (queue_depth == MAX_QUEUE_DEPTH) {
+ __kfree_skb(skb);
+ return;
+ }
+
+ spin_lock_irqsave(&queue_lock, flags);
+ if (!queue_head)
+ queue_head = skb;
+ else
+ queue_tail->next = skb;
+ queue_tail = skb;
+ queue_depth++;
+ spin_unlock_irqrestore(&queue_lock, flags);
+
+ schedule_work(&send_queue);
+}
+
static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, u32 saddr, u32 daddr)
{
- if (uh->check == 0)
+ unsigned int psum;
+
+ if (uh->check == 0 || skb->ip_summed == CHECKSUM_UNNECESSARY)
return 0;
- if (skb->ip_summed == CHECKSUM_HW)
- return csum_tcpudp_magic(
- saddr, daddr, ulen, IPPROTO_UDP, skb->csum);
+ psum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
- skb->csum = csum_tcpudp_nofold(saddr, daddr, ulen, IPPROTO_UDP, 0);
+ if (skb->ip_summed == CHECKSUM_HW &&
+ !(u16)csum_fold(csum_add(psum, skb->csum)))
+ return 0;
+
+ skb->csum = psum;
- return csum_fold(skb_checksum(skb, 0, skb->len, skb->csum));
+ return __skb_checksum_complete(skb);
}
-void netpoll_poll(struct netpoll *np)
+/*
+ * Check whether delayed processing was scheduled for our NIC. If so,
+ * we attempt to grab the poll lock and use ->poll() to pump the card.
+ * If this fails, either we've recursed in ->poll() or it's already
+ * running on another CPU.
+ *
+ * Note: we don't mask interrupts with this lock because we're using
+ * trylock here and interrupts are already disabled in the softirq
+ * case. Further, we test the poll_owner to avoid recursion on UP
+ * systems where the lock doesn't exist.
+ *
+ * In cases where there is bi-directional communications, reading only
+ * one message at a time can lead to packets being dropped by the
+ * network adapter, forcing superfluous retries and possibly timeouts.
+ * Thus, we set our budget to greater than 1.
+ */
+static void poll_napi(struct netpoll *np)
{
- int budget = 1;
+ struct netpoll_info *npinfo = np->dev->npinfo;
+ int budget = 16;
+
+ if (test_bit(__LINK_STATE_RX_SCHED, &np->dev->state) &&
+ npinfo->poll_owner != smp_processor_id() &&
+ spin_trylock(&npinfo->poll_lock)) {
+ npinfo->rx_flags |= NETPOLL_RX_DROP;
+ atomic_inc(&trapped);
+ np->dev->poll(np->dev, &budget);
+
+ atomic_dec(&trapped);
+ npinfo->rx_flags &= ~NETPOLL_RX_DROP;
+ spin_unlock(&npinfo->poll_lock);
+ }
+}
+
+void netpoll_poll(struct netpoll *np)
+{
if(!np->dev || !netif_running(np->dev) || !np->dev->poll_controller)
return;
/* Process pending work on NIC */
np->dev->poll_controller(np->dev);
+ if (np->dev->poll)
+ poll_napi(np);
- /* If scheduling is stopped, tickle NAPI bits */
- if(trapped && np->dev->poll &&
- test_bit(__LINK_STATE_RX_SCHED, &np->dev->state))
- np->dev->poll(np->dev, &budget);
zap_completion_queue();
}
while (clist != NULL) {
struct sk_buff *skb = clist;
clist = clist->next;
- __kfree_skb(skb);
+ if(skb->destructor)
+ dev_kfree_skb_any(skb); /* put this one back */
+ else
+ __kfree_skb(skb);
}
}
if (!skb) {
spin_lock_irqsave(&skb_list_lock, flags);
skb = skbs;
- if (skb)
+ if (skb) {
skbs = skb->next;
- skb->next = NULL;
- nr_skbs--;
+ skb->next = NULL;
+ nr_skbs--;
+ }
spin_unlock_irqrestore(&skb_list_lock, flags);
}
return skb;
}
-void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
int status;
+ struct netpoll_info *npinfo;
-repeat:
- if(!np || !np->dev || !netif_running(np->dev)) {
+ if (!np || !np->dev || !netif_running(np->dev)) {
__kfree_skb(skb);
return;
}
- spin_lock(&np->dev->xmit_lock);
- np->dev->xmit_lock_owner = smp_processor_id();
+ npinfo = np->dev->npinfo;
- status = np->dev->hard_start_xmit(skb, np->dev);
- np->dev->xmit_lock_owner = -1;
- spin_unlock(&np->dev->xmit_lock);
+ /* avoid recursion */
+ if (npinfo->poll_owner == smp_processor_id() ||
+ np->dev->xmit_lock_owner == smp_processor_id()) {
+ if (np->drop)
+ np->drop(skb);
+ else
+ __kfree_skb(skb);
+ return;
+ }
+
+ do {
+ npinfo->tries--;
+ netif_tx_lock(np->dev);
+
+ /*
+ * network drivers do not expect to be called if the queue is
+ * stopped.
+ */
+ if (netif_queue_stopped(np->dev)) {
+ netif_tx_unlock(np->dev);
+ netpoll_poll(np);
+ udelay(50);
+ continue;
+ }
- /* transmit busy */
- if(status) {
+ status = np->dev->hard_start_xmit(skb, np->dev);
+ netif_tx_unlock(np->dev);
+
+ /* success */
+ if(!status) {
+ npinfo->tries = MAX_RETRIES; /* reset */
+ return;
+ }
+
+ /* transmit busy */
netpoll_poll(np);
- goto repeat;
- }
+ udelay(50);
+ } while (npinfo->tries > 0);
}
void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
udp_len = len + sizeof(*udph);
ip_len = eth_len = udp_len + sizeof(*iph);
- total_len = eth_len + ETH_HLEN;
+ total_len = eth_len + ETH_HLEN + NET_IP_ALIGN;
skb = find_skb(np, total_len, total_len - len);
if (!skb)
iph = (struct iphdr *)skb_push(skb, sizeof(*iph));
- iph->version = 4;
- iph->ihl = 5;
+ /* iph->version = 4; iph->ihl = 5; */
+ put_unaligned(0x45, (unsigned char *)iph);
iph->tos = 0;
- iph->tot_len = htons(ip_len);
+ put_unaligned(htons(ip_len), &(iph->tot_len));
iph->id = 0;
iph->frag_off = 0;
iph->ttl = 64;
iph->protocol = IPPROTO_UDP;
iph->check = 0;
- iph->saddr = htonl(np->local_ip);
- iph->daddr = htonl(np->remote_ip);
+ put_unaligned(htonl(np->local_ip), &(iph->saddr));
+ put_unaligned(htonl(np->remote_ip), &(iph->daddr));
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
eth = (struct ethhdr *) skb_push(skb, ETH_HLEN);
memcpy(eth->h_source, np->local_mac, 6);
memcpy(eth->h_dest, np->remote_mac, 6);
+ skb->dev = np->dev;
+
netpoll_send_skb(np, skb);
}
static void arp_reply(struct sk_buff *skb)
{
+ struct netpoll_info *npinfo = skb->dev->npinfo;
struct arphdr *arp;
unsigned char *arp_ptr;
int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
u32 sip, tip;
struct sk_buff *send_skb;
- unsigned long flags;
- struct list_head *p;
- struct netpoll *np = 0;
-
- spin_lock_irqsave(&rx_list_lock, flags);
- list_for_each(p, &rx_list) {
- np = list_entry(p, struct netpoll, rx_list);
- if ( np->dev == skb->dev )
- break;
- np = 0;
- }
- spin_unlock_irqrestore(&rx_list_lock, flags);
+ struct netpoll *np = NULL;
- if (!np) return;
+ if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
+ np = npinfo->rx_np;
+ if (!np)
+ return;
/* No arp on this interface */
if (skb->dev->flags & IFF_NOARP)
netpoll_send_skb(np, send_skb);
}
-int netpoll_rx(struct sk_buff *skb)
+int __netpoll_rx(struct sk_buff *skb)
{
int proto, len, ulen;
struct iphdr *iph;
struct udphdr *uh;
- struct netpoll *np;
- struct list_head *p;
- unsigned long flags;
+ struct netpoll *np = skb->dev->npinfo->rx_np;
+ if (!np)
+ goto out;
if (skb->dev->type != ARPHRD_ETHER)
goto out;
/* check if netpoll clients need ARP */
- if (skb->protocol == __constant_htons(ETH_P_ARP) && trapped) {
+ if (skb->protocol == __constant_htons(ETH_P_ARP) &&
+ atomic_read(&trapped)) {
arp_reply(skb);
return 1;
}
- proto = ntohs(skb->mac.ethernet->h_proto);
+ proto = ntohs(eth_hdr(skb)->h_proto);
if (proto != ETH_P_IP)
goto out;
if (skb->pkt_type == PACKET_OTHERHOST)
if (ulen != len)
goto out;
- if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr) < 0)
+ if (checksum_udp(skb, uh, ulen, iph->saddr, iph->daddr))
+ goto out;
+ if (np->local_ip && np->local_ip != ntohl(iph->daddr))
+ goto out;
+ if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
+ goto out;
+ if (np->local_port && np->local_port != ntohs(uh->dest))
goto out;
- spin_lock_irqsave(&rx_list_lock, flags);
- list_for_each(p, &rx_list) {
- np = list_entry(p, struct netpoll, rx_list);
- if (np->dev && np->dev != skb->dev)
- continue;
- if (np->local_ip && np->local_ip != ntohl(iph->daddr))
- continue;
- if (np->remote_ip && np->remote_ip != ntohl(iph->saddr))
- continue;
- if (np->local_port && np->local_port != ntohs(uh->dest))
- continue;
-
- spin_unlock_irqrestore(&rx_list_lock, flags);
+ np->rx_hook(np, ntohs(uh->source),
+ (char *)(uh+1),
+ ulen - sizeof(struct udphdr));
- if (np->rx_hook)
- np->rx_hook(np, ntohs(uh->source),
- (char *)(uh+1),
- ulen - sizeof(struct udphdr));
+ kfree_skb(skb);
+ return 1;
+out:
+ if (atomic_read(&trapped)) {
+ kfree_skb(skb);
return 1;
}
- spin_unlock_irqrestore(&rx_list_lock, flags);
-out:
- return trapped;
+ return 0;
}
int netpoll_parse_options(struct netpoll *np, char *opt)
if ((delim = strchr(cur, '@')) == NULL)
goto parse_failed;
*delim=0;
- np->local_port=simple_strtol(cur, 0, 10);
+ np->local_port=simple_strtol(cur, NULL, 10);
cur=delim;
}
cur++;
if ((delim = strchr(cur, '@')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_port=simple_strtol(cur, 0, 10);
+ np->remote_port=simple_strtol(cur, NULL, 10);
cur=delim;
}
cur++;
if ((delim = strchr(cur, ':')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_mac[0]=simple_strtol(cur, 0, 16);
+ np->remote_mac[0]=simple_strtol(cur, NULL, 16);
cur=delim+1;
if ((delim = strchr(cur, ':')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_mac[1]=simple_strtol(cur, 0, 16);
+ np->remote_mac[1]=simple_strtol(cur, NULL, 16);
cur=delim+1;
if ((delim = strchr(cur, ':')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_mac[2]=simple_strtol(cur, 0, 16);
+ np->remote_mac[2]=simple_strtol(cur, NULL, 16);
cur=delim+1;
if ((delim = strchr(cur, ':')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_mac[3]=simple_strtol(cur, 0, 16);
+ np->remote_mac[3]=simple_strtol(cur, NULL, 16);
cur=delim+1;
if ((delim = strchr(cur, ':')) == NULL)
goto parse_failed;
*delim=0;
- np->remote_mac[4]=simple_strtol(cur, 0, 16);
+ np->remote_mac[4]=simple_strtol(cur, NULL, 16);
cur=delim+1;
- np->remote_mac[5]=simple_strtol(cur, 0, 16);
+ np->remote_mac[5]=simple_strtol(cur, NULL, 16);
}
printk(KERN_INFO "%s: remote ethernet address "
{
struct net_device *ndev = NULL;
struct in_device *in_dev;
+ struct netpoll_info *npinfo;
+ unsigned long flags;
if (np->dev_name)
ndev = dev_get_by_name(np->dev_name);
np->name, np->dev_name);
return -1;
}
+
+ np->dev = ndev;
+ if (!ndev->npinfo) {
+ npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
+ if (!npinfo)
+ goto release;
+
+ npinfo->rx_flags = 0;
+ npinfo->rx_np = NULL;
+ spin_lock_init(&npinfo->poll_lock);
+ npinfo->poll_owner = -1;
+ npinfo->tries = MAX_RETRIES;
+ spin_lock_init(&npinfo->rx_lock);
+ } else
+ npinfo = ndev->npinfo;
+
if (!ndev->poll_controller) {
printk(KERN_ERR "%s: %s doesn't support polling, aborting.\n",
np->name, np->dev_name);
goto release;
}
- if (!(ndev->flags & IFF_UP)) {
- unsigned short oflags;
+ if (!netif_running(ndev)) {
unsigned long atmost, atleast;
printk(KERN_INFO "%s: device %s not up yet, forcing it\n",
np->name, np->dev_name);
- oflags = ndev->flags;
-
- rtnl_shlock();
- if (dev_change_flags(ndev, oflags | IFF_UP) < 0) {
+ rtnl_lock();
+ if (dev_change_flags(ndev, ndev->flags | IFF_UP) < 0) {
printk(KERN_ERR "%s: failed to open %s\n",
np->name, np->dev_name);
- rtnl_shunlock();
+ rtnl_unlock();
goto release;
}
- rtnl_shunlock();
+ rtnl_unlock();
atleast = jiffies + HZ/10;
- atmost = jiffies + 10*HZ;
+ atmost = jiffies + 4*HZ;
while (!netif_carrier_ok(ndev)) {
if (time_after(jiffies, atmost)) {
printk(KERN_NOTICE
cond_resched();
}
+ /* 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)) {
- printk(KERN_NOTICE "%s: carrier detect appears flaky,"
- " waiting 10 seconds\n",
+ printk(KERN_NOTICE "%s: carrier detect appears"
+ " untrustworthy, waiting 4 seconds\n",
np->name);
- while (time_before(jiffies, atmost))
- cond_resched();
+ msleep(4000);
}
}
- if (!memcmp(np->local_mac, "\0\0\0\0\0\0", 6) && ndev->dev_addr)
+ if (is_zero_ether_addr(np->local_mac) && ndev->dev_addr)
memcpy(np->local_mac, ndev->dev_addr, 6);
if (!np->local_ip) {
- in_dev = in_dev_get(ndev);
+ rcu_read_lock();
+ in_dev = __in_dev_get_rcu(ndev);
- if (!in_dev) {
+ if (!in_dev || !in_dev->ifa_list) {
+ rcu_read_unlock();
printk(KERN_ERR "%s: no IP address for %s, aborting\n",
np->name, np->dev_name);
goto release;
}
np->local_ip = ntohl(in_dev->ifa_list->ifa_local);
- in_dev_put(in_dev);
+ rcu_read_unlock();
printk(KERN_INFO "%s: local IP %d.%d.%d.%d\n",
np->name, HIPQUAD(np->local_ip));
}
- np->dev = ndev;
+ if (np->rx_hook) {
+ spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_flags |= NETPOLL_RX_ENABLED;
+ npinfo->rx_np = np;
+ spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ }
- if(np->rx_hook) {
- unsigned long flags;
+ /* fill up the skb queue */
+ refill_skbs();
-#ifdef CONFIG_NETPOLL_RX
- np->dev->netpoll_rx = 1;
-#endif
+ /* last thing to do is link it to the net device structure */
+ ndev->npinfo = npinfo;
- spin_lock_irqsave(&rx_list_lock, flags);
- list_add(&np->rx_list, &rx_list);
- spin_unlock_irqrestore(&rx_list_lock, flags);
- }
+ /* avoid racing with NAPI reading npinfo */
+ synchronize_rcu();
return 0;
+
release:
+ if (!ndev->npinfo)
+ kfree(npinfo);
+ np->dev = NULL;
dev_put(ndev);
return -1;
}
void netpoll_cleanup(struct netpoll *np)
{
- if(np->rx_hook) {
- unsigned long flags;
-
- spin_lock_irqsave(&rx_list_lock, flags);
- list_del(&np->rx_list);
-#ifdef CONFIG_NETPOLL_RX
- np->dev->netpoll_rx = 0;
-#endif
- spin_unlock_irqrestore(&rx_list_lock, flags);
+ struct netpoll_info *npinfo;
+ unsigned long flags;
+
+ if (np->dev) {
+ npinfo = np->dev->npinfo;
+ if (npinfo && npinfo->rx_np == np) {
+ spin_lock_irqsave(&npinfo->rx_lock, flags);
+ npinfo->rx_np = NULL;
+ npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
+ spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+ }
+ dev_put(np->dev);
}
- dev_put(np->dev);
- np->dev = 0;
+ np->dev = NULL;
}
-int netpoll_trap()
+int netpoll_trap(void)
{
- return trapped;
+ return atomic_read(&trapped);
}
void netpoll_set_trap(int trap)
{
- trapped = trap;
+ if (trap)
+ atomic_inc(&trapped);
+ else
+ atomic_dec(&trapped);
}
EXPORT_SYMBOL(netpoll_set_trap);
EXPORT_SYMBOL(netpoll_parse_options);
EXPORT_SYMBOL(netpoll_setup);
EXPORT_SYMBOL(netpoll_cleanup);
-EXPORT_SYMBOL(netpoll_send_skb);
EXPORT_SYMBOL(netpoll_send_udp);
EXPORT_SYMBOL(netpoll_poll);
+EXPORT_SYMBOL(netpoll_queue);