+ * 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 */
+ NAPI_STATE_DISABLE, /* Disable pending */
+};
+
+extern void __napi_schedule(struct napi_struct *n);
+
+static inline int napi_disable_pending(struct napi_struct *n)
+{
+ return test_bit(NAPI_STATE_DISABLE, &n->state);
+}
+
+/**
+ * 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. We also make
+ * sure there is no pending NAPI disable.
+ */
+static inline int napi_schedule_prep(struct napi_struct *n)
+{
+ return !napi_disable_pending(n) &&
+ !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);
+}
+
+/* Try to reschedule poll. Called by dev->poll() after napi_complete(). */
+static inline int napi_reschedule(struct napi_struct *napi)
+{
+ if (napi_schedule_prep(napi)) {
+ __napi_schedule(napi);
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * 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)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __napi_complete(n);
+ local_irq_restore(flags);
+}
+
+/**
+ * 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)
+{
+ set_bit(NAPI_STATE_DISABLE, &n->state);
+ while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
+ msleep(1);
+ clear_bit(NAPI_STATE_DISABLE, &n->state);
+}
+
+/**
+ * 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);
+}
+
+#ifdef CONFIG_SMP
+/**
+ * napi_synchronize - wait until NAPI is not running
+ * @n: napi context
+ *
+ * Wait until NAPI is done being scheduled on this context.
+ * Waits till any outstanding processing completes but
+ * does not disable future activations.
+ */
+static inline void napi_synchronize(const struct napi_struct *n)
+{
+ while (test_bit(NAPI_STATE_SCHED, &n->state))
+ msleep(1);
+}
+#else
+# define napi_synchronize(n) barrier()
+#endif
+
+/*