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netpoll: Move all receive processing under CONFIG_NETPOLL_TRAP
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Make rx_skb_hook, and rx in struct netpoll depend on
CONFIG_NETPOLL_TRAP Make rx_lock, rx_np, and neigh_tx in struct
netpoll_info depend on CONFIG_NETPOLL_TRAP

Make the functions netpoll_rx_on, netpoll_rx, and netpoll_receive_skb
no-ops when CONFIG_NETPOLL_TRAP is not set.

Only build netpoll_neigh_reply, checksum_udp service_neigh_queue,
pkt_is_ns, and __netpoll_rx when CONFIG_NETPOLL_TRAP is defined.

Add helper functions netpoll_trap_setup, netpoll_trap_setup_info,
netpoll_trap_cleanup, and netpoll_trap_cleanup_info that initialize
and cleanup the struct netpoll and struct netpoll_info receive
specific fields when CONFIG_NETPOLL_TRAP is enabled and do nothing
otherwise.

Signed-off-by: "Eric W. Biederman" <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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@ebiederm @davem330
ebiederm authored and davem330 committed Mar 17, 2014
1 parent 18b3753 commit e1bd4d3
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Showing 2 changed files with 104 additions and 50 deletions.
73 changes: 40 additions & 33 deletions include/linux/netpoll.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -24,32 +24,38 @@ struct netpoll {
struct net_device *dev;
char dev_name[IFNAMSIZ];
const char *name;
void (*rx_skb_hook)(struct netpoll *np, int source, struct sk_buff *skb,
int offset, int len);

union inet_addr local_ip, remote_ip;
bool ipv6;
u16 local_port, remote_port;
u8 remote_mac[ETH_ALEN];

struct list_head rx; /* rx_np list element */
struct work_struct cleanup_work;

#ifdef CONFIG_NETPOLL_TRAP
void (*rx_skb_hook)(struct netpoll *np, int source, struct sk_buff *skb,
int offset, int len);
struct list_head rx; /* rx_np list element */
#endif
};

struct netpoll_info {
atomic_t refcnt;

spinlock_t rx_lock;
struct semaphore dev_lock;
struct list_head rx_np; /* netpolls that registered an rx_skb_hook */

struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
struct sk_buff_head txq;

struct delayed_work tx_work;

struct netpoll *netpoll;
struct rcu_head rcu;

#ifdef CONFIG_NETPOLL_TRAP
spinlock_t rx_lock;
struct list_head rx_np; /* netpolls that registered an rx_skb_hook */
struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
#endif
};

#ifdef CONFIG_NETPOLL
Expand All @@ -68,7 +74,6 @@ int netpoll_setup(struct netpoll *np);
void __netpoll_cleanup(struct netpoll *np);
void __netpoll_free_async(struct netpoll *np);
void netpoll_cleanup(struct netpoll *np);
int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
struct net_device *dev);
static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
Expand All @@ -82,25 +87,12 @@ static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
#ifdef CONFIG_NETPOLL_TRAP
int netpoll_trap(void);
void netpoll_set_trap(int trap);
int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
static inline bool netpoll_rx_processing(struct netpoll_info *npinfo)
{
return !list_empty(&npinfo->rx_np);
}
#else
static inline int netpoll_trap(void)
{
return 0;
}
static inline void netpoll_set_trap(int trap)
{
}
static inline bool netpoll_rx_processing(struct netpoll_info *npinfo)
{
return false;
}
#endif

#ifdef CONFIG_NETPOLL
static inline bool netpoll_rx_on(struct sk_buff *skb)
{
struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
Expand Down Expand Up @@ -138,6 +130,33 @@ static inline int netpoll_receive_skb(struct sk_buff *skb)
return 0;
}

#else
static inline int netpoll_trap(void)
{
return 0;
}
static inline void netpoll_set_trap(int trap)
{
}
static inline bool netpoll_rx_processing(struct netpoll_info *npinfo)
{
return false;
}
static inline bool netpoll_rx(struct sk_buff *skb)
{
return false;
}
static inline bool netpoll_rx_on(struct sk_buff *skb)
{
return false;
}
static inline int netpoll_receive_skb(struct sk_buff *skb)
{
return 0;
}
#endif

#ifdef CONFIG_NETPOLL
static inline void *netpoll_poll_lock(struct napi_struct *napi)
{
struct net_device *dev = napi->dev;
Expand Down Expand Up @@ -166,18 +185,6 @@ static inline bool netpoll_tx_running(struct net_device *dev)
}

#else
static inline bool netpoll_rx(struct sk_buff *skb)
{
return false;
}
static inline bool netpoll_rx_on(struct sk_buff *skb)
{
return false;
}
static inline int netpoll_receive_skb(struct sk_buff *skb)
{
return 0;
}
static inline void *netpoll_poll_lock(struct napi_struct *napi)
{
return NULL;
Expand Down
81 changes: 64 additions & 17 deletions net/core/netpoll.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ static struct sk_buff_head skb_pool;

#ifdef CONFIG_NETPOLL_TRAP
static atomic_t trapped;
static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
#endif

DEFINE_STATIC_SRCU(netpoll_srcu);
Expand All @@ -61,7 +62,6 @@ DEFINE_STATIC_SRCU(netpoll_srcu);
MAX_UDP_CHUNK)

static void zap_completion_queue(void);
static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo);
static void netpoll_async_cleanup(struct work_struct *work);

static unsigned int carrier_timeout = 4;
Expand Down Expand Up @@ -109,6 +109,7 @@ static void queue_process(struct work_struct *work)
}
}

#ifdef CONFIG_NETPOLL_TRAP
static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,
unsigned short ulen, __be32 saddr, __be32 daddr)
{
Expand All @@ -127,6 +128,7 @@ static __sum16 checksum_udp(struct sk_buff *skb, struct udphdr *uh,

return __skb_checksum_complete(skb);
}
#endif /* CONFIG_NETPOLL_TRAP */

/*
* Check whether delayed processing was scheduled for our NIC. If so,
Expand Down Expand Up @@ -179,6 +181,7 @@ static void poll_napi(struct net_device *dev, int budget)
}
}

#ifdef CONFIG_NETPOLL_TRAP
static void service_neigh_queue(struct net_device *dev,
struct netpoll_info *npi)
{
Expand All @@ -197,6 +200,12 @@ static void service_neigh_queue(struct net_device *dev,
while ((skb = skb_dequeue(&npi->neigh_tx)))
netpoll_neigh_reply(skb, npi);
}
#else /* !CONFIG_NETPOLL_TRAP */
static inline void service_neigh_queue(struct net_device *dev,
struct netpoll_info *npi)
{
}
#endif /* CONFIG_NETPOLL_TRAP */

static void netpoll_poll_dev(struct net_device *dev)
{
Expand Down Expand Up @@ -522,6 +531,7 @@ void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
}
EXPORT_SYMBOL(netpoll_send_udp);

#ifdef CONFIG_NETPOLL_TRAP
static void netpoll_neigh_reply(struct sk_buff *skb, struct netpoll_info *npinfo)
{
int size, type = ARPOP_REPLY;
Expand Down Expand Up @@ -900,6 +910,55 @@ int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo)
return 0;
}

static void netpoll_trap_setup_info(struct netpoll_info *npinfo)
{
INIT_LIST_HEAD(&npinfo->rx_np);
spin_lock_init(&npinfo->rx_lock);
skb_queue_head_init(&npinfo->neigh_tx);
}

static void netpoll_trap_cleanup_info(struct netpoll_info *npinfo)
{
skb_queue_purge(&npinfo->neigh_tx);
}

static void netpoll_trap_setup(struct netpoll *np, struct netpoll_info *npinfo)
{
unsigned long flags;
if (np->rx_skb_hook) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_add_tail(&np->rx, &npinfo->rx_np);
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
}

static void netpoll_trap_cleanup(struct netpoll *np, struct netpoll_info *npinfo)
{
unsigned long flags;
if (!list_empty(&npinfo->rx_np)) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_del(&np->rx);
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
}

#else /* !CONFIG_NETPOLL_TRAP */
static inline void netpoll_trap_setup_info(struct netpoll_info *npinfo)
{
}
static inline void netpoll_trap_cleanup_info(struct netpoll_info *npinfo)
{
}
static inline
void netpoll_trap_setup(struct netpoll *np, struct netpoll_info *npinfo)
{
}
static inline
void netpoll_trap_cleanup(struct netpoll *np, struct netpoll_info *npinfo)
{
}
#endif /* CONFIG_NETPOLL_TRAP */

void netpoll_print_options(struct netpoll *np)
{
np_info(np, "local port %d\n", np->local_port);
Expand Down Expand Up @@ -1023,7 +1082,6 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
{
struct netpoll_info *npinfo;
const struct net_device_ops *ops;
unsigned long flags;
int err;

np->dev = ndev;
Expand All @@ -1045,11 +1103,9 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)
goto out;
}

INIT_LIST_HEAD(&npinfo->rx_np);
netpoll_trap_setup_info(npinfo);

spin_lock_init(&npinfo->rx_lock);
sema_init(&npinfo->dev_lock, 1);
skb_queue_head_init(&npinfo->neigh_tx);
skb_queue_head_init(&npinfo->txq);
INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);

Expand All @@ -1068,11 +1124,7 @@ int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp)

npinfo->netpoll = np;

if (np->rx_skb_hook) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_add_tail(&np->rx, &npinfo->rx_np);
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
netpoll_trap_setup(np, npinfo);

/* last thing to do is link it to the net device structure */
rcu_assign_pointer(ndev->npinfo, npinfo);
Expand Down Expand Up @@ -1222,7 +1274,7 @@ 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->neigh_tx);
netpoll_trap_cleanup_info(npinfo);
skb_queue_purge(&npinfo->txq);

/* we can't call cancel_delayed_work_sync here, as we are in softirq */
Expand All @@ -1238,7 +1290,6 @@ static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
void __netpoll_cleanup(struct netpoll *np)
{
struct netpoll_info *npinfo;
unsigned long flags;

/* rtnl_dereference would be preferable here but
* rcu_cleanup_netpoll path can put us in here safely without
Expand All @@ -1248,11 +1299,7 @@ void __netpoll_cleanup(struct netpoll *np)
if (!npinfo)
return;

if (!list_empty(&npinfo->rx_np)) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
list_del(&np->rx);
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
netpoll_trap_cleanup(np, npinfo);

synchronize_srcu(&netpoll_srcu);

Expand Down

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