datapath/linux/compat/include/linux/workqueue.h

   1 #ifndef __LINUX_WORKQUEUE_WRAPPER_H
   2 #define __LINUX_WORKQUEUE_WRAPPER_H 1
   3
   4 #include <linux/timer.h>
   5
   6 int __init ovs_workqueues_init(void);
   7 void ovs_workqueues_exit(void);
   8
   9 /* Older kernels have an implementation of work queues with some very bad
  10  * characteristics when trying to cancel work (potential deadlocks, use after
  11  * free, etc.  Therefore we implement simple ovs specific work queue using
  12  * single worker thread. work-queue API are kept similar for compatibility.
  13  * It seems it is useful even on newer kernel. As it can avoid system wide
  14  * freeze in event of softlockup due to workq blocked on genl_lock.
  15  */
  16
  17 struct work_struct;
  18
  19 typedef void (*work_func_t)(struct work_struct *work);
  20
  21 #define work_data_bits(work) ((unsigned long *)(&(work)->data))
  22
  23 struct work_struct {
  24 #define WORK_STRUCT_PENDING 0           /* T if work item pending execution */
  25         atomic_long_t data;
  26         struct list_head entry;
  27         work_func_t func;
  28 #ifdef CONFIG_LOCKDEP
  29         struct lockdep_map lockdep_map;
  30 #endif
  31 };
  32
  33 #define WORK_DATA_INIT()        ATOMIC_LONG_INIT(0)
  34
  35 #define work_clear_pending(work)                                \
  36         clear_bit(WORK_STRUCT_PENDING, work_data_bits(work))
  37
  38 struct delayed_work {
  39         struct work_struct work;
  40         struct timer_list timer;
  41 };
  42
  43 #define __WORK_INITIALIZER(n, f) {                              \
  44         .data = WORK_DATA_INIT(),                               \
  45         .entry  = { &(n).entry, &(n).entry },                   \
  46         .func = (f),                                            \
  47 }
  48
  49 #define __DELAYED_WORK_INITIALIZER(n, f) {                      \
  50         .work = __WORK_INITIALIZER((n).work, (f)),              \
  51         .timer = TIMER_INITIALIZER(NULL, 0, 0),                 \
  52 }
  53
  54 #define DECLARE_DELAYED_WORK(n, f)                              \
  55         struct delayed_work n = __DELAYED_WORK_INITIALIZER(n, f)
  56
  57 #define schedule_delayed_work rpl_schedule_delayed_work
  58 int schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
  59
  60 #define cancel_delayed_work_sync rpl_cancel_delayed_work_sync
  61 int cancel_delayed_work_sync(struct delayed_work *dwork);
  62
  63 #define INIT_WORK(_work, _func)                                 \
  64         do {                                                    \
  65                 (_work)->data = (atomic_long_t) WORK_DATA_INIT();       \
  66                 INIT_LIST_HEAD(&(_work)->entry);                \
  67                 (_work)->func = (_func);                        \
  68         } while (0)
  69
  70 extern void flush_scheduled_work(void);
  71 extern void queue_work(struct work_struct *work);
  72 extern bool cancel_work_sync(struct work_struct *work);
  73
  74 #endif