2 files changed, 330 insertions, 86 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index e679b2751665..b93575db8cce 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -31,6 +31,7 @@
 
 #ifdef __KERNEL__
 #include <linux/timer.h>
+#include <linux/delay.h>
 #include <asm/atomic.h>
 #include <asm/cache.h>
 #include <asm/byteorder.h>
@@ -38,6 +39,7 @@
 #include <linux/device.h>
 #include <linux/percpu.h>
 #include <linux/dmaengine.h>
+#include <linux/workqueue.h>
 
 struct vlan_group;
 struct ethtool_ops;
@@ -258,7 +260,6 @@ enum netdev_state_t
         __LINK_STATE_PRESENT,
         __LINK_STATE_SCHED,
         __LINK_STATE_NOCARRIER,
-        __LINK_STATE_RX_SCHED,
         __LINK_STATE_LINKWATCH_PENDING,
         __LINK_STATE_DORMANT,
         __LINK_STATE_QDISC_RUNNING,
@@ -278,6 +279,110 @@ struct netdev_boot_setup {
 extern int __init netdev_boot_setup(char *str);
 
 /*
+ * Structure for NAPI scheduling similar to tasklet but with weighting
+ */
+struct napi_struct {
+        /* The poll_list must only be managed by the entity which
+         * changes the state of the NAPI_STATE_SCHED bit.  This means
+         * whoever atomically sets that bit can add this napi_struct
+         * to the per-cpu poll_list, and whoever clears that bit
+         * can remove from the list right before clearing the bit.
+         */
+        struct list_head        poll_list;
+
+        unsigned long           state;
+        int                     weight;
+        int                     (*poll)(struct napi_struct *, int);
+#ifdef CONFIG_NETPOLL
+        spinlock_t              poll_lock;
+        int                     poll_owner;
+        struct net_device       *dev;
+        struct list_head        dev_list;
+#endif
+};
+
+enum
+{
+        NAPI_STATE_SCHED,       /* Poll is scheduled */
+};
+
+extern void FASTCALL(__napi_schedule(struct napi_struct *n));
+
+/**
+ *      napi_schedule_prep - check if napi can be scheduled
+ *      @n: napi context
+ *
+ * Test if NAPI routine is already running, and if not mark
+ * it as running.  This is used as a condition variable
+ * insure only one NAPI poll instance runs
+ */
+static inline int napi_schedule_prep(struct napi_struct *n)
+{
+        return !test_and_set_bit(NAPI_STATE_SCHED, &n->state);
+}
+
+/**
+ *      napi_schedule - schedule NAPI poll
+ *      @n: napi context
+ *
+ * Schedule NAPI poll routine to be called if it is not already
+ * running.
+ */
+static inline void napi_schedule(struct napi_struct *n)
+{
+        if (napi_schedule_prep(n))
+                __napi_schedule(n);
+}
+
+/**
+ *      napi_complete - NAPI processing complete
+ *      @n: napi context
+ *
+ * Mark NAPI processing as complete.
+ */
+static inline void __napi_complete(struct napi_struct *n)
+{
+        BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
+        list_del(&n->poll_list);
+        smp_mb__before_clear_bit();
+        clear_bit(NAPI_STATE_SCHED, &n->state);
+}
+
+static inline void napi_complete(struct napi_struct *n)
+{
+        local_irq_disable();
+        __napi_complete(n);
+        local_irq_enable();
+}
+
+/**
+ *      napi_disable - prevent NAPI from scheduling
+ *      @n: napi context
+ *
+ * Stop NAPI from being scheduled on this context.
+ * Waits till any outstanding processing completes.
+ */
+static inline void napi_disable(struct napi_struct *n)
+{
+        while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
+                msleep_interruptible(1);
+}
+
+/**
+ *      napi_enable - enable NAPI scheduling
+ *      @n: napi context
+ *
+ * Resume NAPI from being scheduled on this context.
+ * Must be paired with napi_disable.
+ */
+static inline void napi_enable(struct napi_struct *n)
+{
+        BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
+        smp_mb__before_clear_bit();
+        clear_bit(NAPI_STATE_SCHED, &n->state);
+}
+
+/*
  *      The DEVICE structure.
  *      Actually, this whole structure is a big mistake.  It mixes I/O
  *      data with strictly "high-level" data, and it has to know about
@@ -319,6 +424,9 @@ struct net_device
         unsigned long           state;
 
         struct list_head        dev_list;
+#ifdef CONFIG_NETPOLL
+        struct list_head        napi_list;
+#endif
         
         /* The device initialization function. Called only once. */
         int                     (*init)(struct net_device *dev);
@@ -430,12 +538,6 @@ struct net_device
 /*
  * Cache line mostly used on receive path (including eth_type_trans())
  */
-        struct list_head        poll_list ____cacheline_aligned_in_smp;
-                                        /* Link to poll list    */
-
-        int                     (*poll) (struct net_device *dev, int *quota);
-        int                     quota;
-        int                     weight;
         unsigned long           last_rx;        /* Time of last Rx      */
         /* Interface address info used in eth_type_trans() */
         unsigned char           dev_addr[MAX_ADDR_LEN]; /* hw address, (before bcast 
@@ -582,6 +684,12 @@ struct net_device
 #define NETDEV_ALIGN            32
 #define NETDEV_ALIGN_CONST      (NETDEV_ALIGN - 1)
 
+/**
+ *      netdev_priv - access network device private data
+ *      @dev: network device
+ *
+ * Get network device private data
+ */
 static inline void *netdev_priv(const struct net_device *dev)
 {
         return dev->priv;
@@ -593,6 +701,23 @@ static inline void *netdev_priv(const struct net_device *dev)
  */
 #define SET_NETDEV_DEV(net, pdev)       ((net)->dev.parent = (pdev))
 
+static inline void netif_napi_add(struct net_device *dev,
+                                  struct napi_struct *napi,
+                                  int (*poll)(struct napi_struct *, int),
+                                  int weight)
+{
+        INIT_LIST_HEAD(&napi->poll_list);
+        napi->poll = poll;
+        napi->weight = weight;
+#ifdef CONFIG_NETPOLL
+        napi->dev = dev;
+        list_add(&napi->dev_list, &dev->napi_list);
+        spin_lock_init(&napi->poll_lock);
+        napi->poll_owner = -1;
+#endif
+        set_bit(NAPI_STATE_SCHED, &napi->state);
+}
+
 struct packet_type {
         __be16                  type;   /* This is really htons(ether_type). */
         struct net_device       *dev;   /* NULL is wildcarded here           */
@@ -678,7 +803,6 @@ static inline int unregister_gifconf(unsigned int family)
  * Incoming packets are placed on per-cpu queues so that
  * no locking is needed.
  */
-
 struct softnet_data
 {
         struct net_device       *output_queue;
@@ -686,7 +810,7 @@ struct softnet_data
         struct list_head        poll_list;
         struct sk_buff          *completion_queue;
 
-        struct net_device       backlog_dev;    /* Sorry. 8) */
+        struct napi_struct      backlog;
 #ifdef CONFIG_NET_DMA
         struct dma_chan         *net_dma;
 #endif
@@ -704,11 +828,24 @@ static inline void netif_schedule(struct net_device *dev)
                 __netif_schedule(dev);
 }
 
+/**
+ *      netif_start_queue - allow transmit
+ *      @dev: network device
+ *
+ *      Allow upper layers to call the device hard_start_xmit routine.
+ */
 static inline void netif_start_queue(struct net_device *dev)
 {
         clear_bit(__LINK_STATE_XOFF, &dev->state);
 }
 
+/**
+ *      netif_wake_queue - restart transmit
+ *      @dev: network device
+ *
+ *      Allow upper layers to call the device hard_start_xmit routine.
+ *      Used for flow control when transmit resources are available.
+ */
 static inline void netif_wake_queue(struct net_device *dev)
 {
 #ifdef CONFIG_NETPOLL_TRAP
@@ -721,16 +858,35 @@ static inline void netif_wake_queue(struct net_device *dev)
                 __netif_schedule(dev);
 }
 
+/**
+ *      netif_stop_queue - stop transmitted packets
+ *      @dev: network device
+ *
+ *      Stop upper layers calling the device hard_start_xmit routine.
+ *      Used for flow control when transmit resources are unavailable.
+ */
 static inline void netif_stop_queue(struct net_device *dev)
 {
         set_bit(__LINK_STATE_XOFF, &dev->state);
 }
 
+/**
+ *      netif_queue_stopped - test if transmit queue is flowblocked
+ *      @dev: network device
+ *
+ *      Test if transmit queue on device is currently unable to send.
+ */
 static inline int netif_queue_stopped(const struct net_device *dev)
 {
         return test_bit(__LINK_STATE_XOFF, &dev->state);
 }
 
+/**
+ *      netif_running - test if up
+ *      @dev: network device
+ *
+ *      Test if the device has been brought up.
+ */
 static inline int netif_running(const struct net_device *dev)
 {
         return test_bit(__LINK_STATE_START, &dev->state);
@@ -742,6 +898,14 @@ static inline int netif_running(const struct net_device *dev)
  * done at the overall netdevice level.
  * Also test the device if we're multiqueue.
  */
+
+/**
+ *      netif_start_subqueue - allow sending packets on subqueue
+ *      @dev: network device
+ *      @queue_index: sub queue index
+ *
+ * Start individual transmit queue of a device with multiple transmit queues.
+ */
 static inline void netif_start_subqueue(struct net_device *dev, u16 queue_index)
 {
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
@@ -749,6 +913,13 @@ static inline void netif_start_subqueue(struct net_device *dev, u16 queue_index)
 #endif
 }
 
+/**
+ *      netif_stop_subqueue - stop sending packets on subqueue
+ *      @dev: network device
+ *      @queue_index: sub queue index
+ *
+ * Stop individual transmit queue of a device with multiple transmit queues.
+ */
 static inline void netif_stop_subqueue(struct net_device *dev, u16 queue_index)
 {
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
@@ -760,6 +931,13 @@ static inline void netif_stop_subqueue(struct net_device *dev, u16 queue_index)
 #endif
 }
 
+/**
+ *      netif_subqueue_stopped - test status of subqueue
+ *      @dev: network device
+ *      @queue_index: sub queue index
+ *
+ * Check individual transmit queue of a device with multiple transmit queues.
+ */
 static inline int netif_subqueue_stopped(const struct net_device *dev,
                                          u16 queue_index)
 {
@@ -771,6 +949,14 @@ static inline int netif_subqueue_stopped(const struct net_device *dev,
 #endif
 }
 
+
+/**
+ *      netif_wake_subqueue - allow sending packets on subqueue
+ *      @dev: network device
+ *      @queue_index: sub queue index
+ *
+ * Resume individual transmit queue of a device with multiple transmit queues.
+ */
 static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
 {
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
@@ -784,6 +970,13 @@ static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
 #endif
 }
 
+/**
+ *      netif_is_multiqueue - test if device has multiple transmit queues
+ *      @dev: network device
+ *
+ * Check if device has multiple transmit queues
+ * Always falls if NETDEVICE_MULTIQUEUE is not configured
+ */
 static inline int netif_is_multiqueue(const struct net_device *dev)
 {
 #ifdef CONFIG_NETDEVICES_MULTIQUEUE
@@ -796,20 +989,7 @@ static inline int netif_is_multiqueue(const struct net_device *dev)
 /* Use this variant when it is known for sure that it
  * is executing from interrupt context.
  */
-static inline void dev_kfree_skb_irq(struct sk_buff *skb)
-{
-        if (atomic_dec_and_test(&skb->users)) {
-                struct softnet_data *sd;
-                unsigned long flags;
-
-                local_irq_save(flags);
-                sd = &__get_cpu_var(softnet_data);
-                skb->next = sd->completion_queue;
-                sd->completion_queue = skb;
-                raise_softirq_irqoff(NET_TX_SOFTIRQ);
-                local_irq_restore(flags);
-        }
-}
+extern void dev_kfree_skb_irq(struct sk_buff *skb);
 
 /* Use this variant in places where it could be invoked
  * either from interrupt or non-interrupt context.
@@ -833,18 +1013,28 @@ extern int		dev_set_mac_address(struct net_device *,
 extern int              dev_hard_start_xmit(struct sk_buff *skb,
                                             struct net_device *dev);
 
-extern void             dev_init(void);
-
 extern int              netdev_budget;
 
 /* Called by rtnetlink.c:rtnl_unlock() */
 extern void netdev_run_todo(void);
 
+/**
+ *      dev_put - release reference to device
+ *      @dev: network device
+ *
+ * Hold reference to device to keep it from being freed.
+ */
 static inline void dev_put(struct net_device *dev)
 {
         atomic_dec(&dev->refcnt);
 }
 
+/**
+ *      dev_hold - get reference to device
+ *      @dev: network device
+ *
+ * Release reference to device to allow it to be freed.
+ */
 static inline void dev_hold(struct net_device *dev)
 {
         atomic_inc(&dev->refcnt);
@@ -861,6 +1051,12 @@ static inline void dev_hold(struct net_device *dev)
 
 extern void linkwatch_fire_event(struct net_device *dev);
 
+/**
+ *      netif_carrier_ok - test if carrier present
+ *      @dev: network device
+ *
+ * Check if carrier is present on device
+ */
 static inline int netif_carrier_ok(const struct net_device *dev)
 {
         return !test_bit(__LINK_STATE_NOCARRIER, &dev->state);
@@ -872,30 +1068,66 @@ extern void netif_carrier_on(struct net_device *dev);
 
 extern void netif_carrier_off(struct net_device *dev);
 
+/**
+ *      netif_dormant_on - mark device as dormant.
+ *      @dev: network device
+ *
+ * Mark device as dormant (as per RFC2863).
+ *
+ * The dormant state indicates that the relevant interface is not
+ * actually in a condition to pass packets (i.e., it is not 'up') but is
+ * in a "pending" state, waiting for some external event.  For "on-
+ * demand" interfaces, this new state identifies the situation where the
+ * interface is waiting for events to place it in the up state.
+ *
+ */
 static inline void netif_dormant_on(struct net_device *dev)
 {
         if (!test_and_set_bit(__LINK_STATE_DORMANT, &dev->state))
                 linkwatch_fire_event(dev);
 }
 
+/**
+ *      netif_dormant_off - set device as not dormant.
+ *      @dev: network device
+ *
+ * Device is not in dormant state.
+ */
 static inline void netif_dormant_off(struct net_device *dev)
 {
         if (test_and_clear_bit(__LINK_STATE_DORMANT, &dev->state))
                 linkwatch_fire_event(dev);
 }
 
+/**
+ *      netif_dormant - test if carrier present
+ *      @dev: network device
+ *
+ * Check if carrier is present on device
+ */
 static inline int netif_dormant(const struct net_device *dev)
 {
         return test_bit(__LINK_STATE_DORMANT, &dev->state);
 }
 
 
+/**
+ *      netif_oper_up - test if device is operational
+ *      @dev: network device
+ *
+ * Check if carrier is operational
+ */
 static inline int netif_oper_up(const struct net_device *dev) {
         return (dev->operstate == IF_OPER_UP ||
                 dev->operstate == IF_OPER_UNKNOWN /* backward compat */);
 }
 
-/* Hot-plugging. */
+/**
+ *      netif_device_present - is device available or removed
+ *      @dev: network device
+ *
+ * Check if device has not been removed from system.
+ */
 static inline int netif_device_present(struct net_device *dev)
 {
         return test_bit(__LINK_STATE_PRESENT, &dev->state);
@@ -955,46 +1187,38 @@ static inline u32 netif_msg_init(int debug_value, int default_msg_enable_bits)
         return (1 << debug_value) - 1;
 }
 
-/* Test if receive needs to be scheduled */
-static inline int __netif_rx_schedule_prep(struct net_device *dev)
-{
-        return !test_and_set_bit(__LINK_STATE_RX_SCHED, &dev->state);
-}
-
 /* Test if receive needs to be scheduled but only if up */
-static inline int netif_rx_schedule_prep(struct net_device *dev)
+static inline int netif_rx_schedule_prep(struct net_device *dev,
+                                         struct napi_struct *napi)
 {
-        return netif_running(dev) && __netif_rx_schedule_prep(dev);
+        return netif_running(dev) && napi_schedule_prep(napi);
 }
 
 /* Add interface to tail of rx poll list. This assumes that _prep has
  * already been called and returned 1.
  */
-
-extern void __netif_rx_schedule(struct net_device *dev);
+static inline void __netif_rx_schedule(struct net_device *dev,
+                                       struct napi_struct *napi)
+{
+        dev_hold(dev);
+        __napi_schedule(napi);
+}
 
 /* Try to reschedule poll. Called by irq handler. */
 
-static inline void netif_rx_schedule(struct net_device *dev)
+static inline void netif_rx_schedule(struct net_device *dev,
+                                     struct napi_struct *napi)
 {
-        if (netif_rx_schedule_prep(dev))
-                __netif_rx_schedule(dev);
+        if (netif_rx_schedule_prep(dev, napi))
+                __netif_rx_schedule(dev, napi);
 }
 
-/* Try to reschedule poll. Called by dev->poll() after netif_rx_complete().
- * Do not inline this?
- */
-static inline int netif_rx_reschedule(struct net_device *dev, int undo)
+/* Try to reschedule poll. Called by dev->poll() after netif_rx_complete().  */
+static inline int netif_rx_reschedule(struct net_device *dev,
+                                      struct napi_struct *napi)
 {
-        if (netif_rx_schedule_prep(dev)) {
-                unsigned long flags;
-
-                dev->quota += undo;
-
-                local_irq_save(flags);
-                list_add_tail(&dev->poll_list, &__get_cpu_var(softnet_data).poll_list);
-                __raise_softirq_irqoff(NET_RX_SOFTIRQ);
-                local_irq_restore(flags);
+        if (napi_schedule_prep(napi)) {
+                __netif_rx_schedule(dev, napi);
                 return 1;
         }
         return 0;
@@ -1003,12 +1227,11 @@ static inline int netif_rx_reschedule(struct net_device *dev, int undo)
 /* same as netif_rx_complete, except that local_irq_save(flags)
  * has already been issued
  */
-static inline void __netif_rx_complete(struct net_device *dev)
+static inline void __netif_rx_complete(struct net_device *dev,
+                                       struct napi_struct *napi)
 {
-        BUG_ON(!test_bit(__LINK_STATE_RX_SCHED, &dev->state));
-        list_del(&dev->poll_list);
-        smp_mb__before_clear_bit();
-        clear_bit(__LINK_STATE_RX_SCHED, &dev->state);
+        __napi_complete(napi);
+        dev_put(dev);
 }
 
 /* Remove interface from poll list: it must be in the poll list
@@ -1016,28 +1239,22 @@ static inline void __netif_rx_complete(struct net_device *dev)
  * it completes the work. The device cannot be out of poll list at this
  * moment, it is BUG().
  */
-static inline void netif_rx_complete(struct net_device *dev)
+static inline void netif_rx_complete(struct net_device *dev,
+                                     struct napi_struct *napi)
 {
         unsigned long flags;
 
         local_irq_save(flags);
-        __netif_rx_complete(dev);
+        __netif_rx_complete(dev, napi);
         local_irq_restore(flags);
 }
 
-static inline void netif_poll_disable(struct net_device *dev)
-{
-        while (test_and_set_bit(__LINK_STATE_RX_SCHED, &dev->state))
-                /* No hurry. */
-                schedule_timeout_interruptible(1);
-}
-
-static inline void netif_poll_enable(struct net_device *dev)
-{
-        smp_mb__before_clear_bit();
-        clear_bit(__LINK_STATE_RX_SCHED, &dev->state);
-}
-
+/**
+ *      netif_tx_lock - grab network device transmit lock
+ *      @dev: network device
+ *
+ * Get network device transmit lock
+ */
 static inline void netif_tx_lock(struct net_device *dev)
 {
         spin_lock(&dev->_xmit_lock);
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h
index 29930b71a9aa..08dcc39ec18d 100644
--- a/include/linux/netpoll.h
+++ b/include/linux/netpoll.h
@@ -25,8 +25,6 @@ struct netpoll {
 
 struct netpoll_info {
         atomic_t refcnt;
-        spinlock_t poll_lock;
-        int poll_owner;
         int rx_flags;
         spinlock_t rx_lock;
         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
@@ -64,32 +62,61 @@ static inline int netpoll_rx(struct sk_buff *skb)
         return ret;
 }
 
-static inline void *netpoll_poll_lock(struct net_device *dev)
+static inline int netpoll_receive_skb(struct sk_buff *skb)
 {
+        if (!list_empty(&skb->dev->napi_list))
+                return netpoll_rx(skb);
+        return 0;
+}
+
+static inline void *netpoll_poll_lock(struct napi_struct *napi)
+{
+        struct net_device *dev = napi->dev;
+
         rcu_read_lock(); /* deal with race on ->npinfo */
-        if (dev->npinfo) {
-                spin_lock(&dev->npinfo->poll_lock);
-                dev->npinfo->poll_owner = smp_processor_id();
-                return dev->npinfo;
+        if (dev && dev->npinfo) {
+                spin_lock(&napi->poll_lock);
+                napi->poll_owner = smp_processor_id();
+                return napi;
         }
         return NULL;
 }
 
 static inline void netpoll_poll_unlock(void *have)
 {
-        struct netpoll_info *npi = have;
+        struct napi_struct *napi = have;
 
-        if (npi) {
-                npi->poll_owner = -1;
-                spin_unlock(&npi->poll_lock);
+        if (napi) {
+                napi->poll_owner = -1;
+                spin_unlock(&napi->poll_lock);
         }
         rcu_read_unlock();
 }
 
+static inline void netpoll_netdev_init(struct net_device *dev)
+{
+        INIT_LIST_HEAD(&dev->napi_list);
+}
+
 #else
-#define netpoll_rx(a) 0
-#define netpoll_poll_lock(a) NULL
-#define netpoll_poll_unlock(a)
+static inline int netpoll_rx(struct sk_buff *skb)
+{
+        return 0;
+}
+static inline int netpoll_receive_skb(struct sk_buff *skb)
+{
+        return 0;
+}
+static inline void *netpoll_poll_lock(struct napi_struct *napi)
+{
+        return NULL;
+}
+static inline void netpoll_poll_unlock(void *have)
+{
+}
+static inline void netpoll_netdev_init(struct net_device *dev)
+{
+}
 #endif
 
 #endif