1 #ifndef _LINUX_KTHREAD_H 2 #define _LINUX_KTHREAD_H 3 /* Simple interface for creating and stopping kernel threads without mess. */ 4 #include <linux/err.h> 5 #include <linux/sched.h> 6 7 __printf(4, 5) 8 struct task_struct *kthread_create_on_node(int (*threadfn)(void *data), 9 void *data, 10 int node, 11 const char namefmt[], ...); 12 13 /** 14 * kthread_create - create a kthread on the current node 15 * @threadfn: the function to run in the thread 16 * @data: data pointer for @threadfn() 17 * @namefmt: printf-style format string for the thread name 18 * @arg...: arguments for @namefmt. 19 * 20 * This macro will create a kthread on the current node, leaving it in 21 * the stopped state. This is just a helper for kthread_create_on_node(); 22 * see the documentation there for more details. 23 */ 24 #define kthread_create(threadfn, data, namefmt, arg...) \ 25 kthread_create_on_node(threadfn, data, NUMA_NO_NODE, namefmt, ##arg) 26 27 28 struct task_struct *kthread_create_on_cpu(int (*threadfn)(void *data), 29 void *data, 30 unsigned int cpu, 31 const char *namefmt); 32 33 /** 34 * kthread_run - create and wake a thread. 35 * @threadfn: the function to run until signal_pending(current). 36 * @data: data ptr for @threadfn. 37 * @namefmt: printf-style name for the thread. 38 * 39 * Description: Convenient wrapper for kthread_create() followed by 40 * wake_up_process(). Returns the kthread or ERR_PTR(-ENOMEM). 41 */ 42 #define kthread_run(threadfn, data, namefmt, ...) \ 43 ({ \ 44 struct task_struct *__k \ 45 = kthread_create(threadfn, data, namefmt, ## __VA_ARGS__); \ 46 if (!IS_ERR(__k)) \ 47 wake_up_process(__k); \ 48 __k; \ 49 }) 50 51 void free_kthread_struct(struct task_struct *k); 52 void kthread_bind(struct task_struct *k, unsigned int cpu); 53 void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask); 54 int kthread_stop(struct task_struct *k); 55 bool kthread_should_stop(void); 56 bool kthread_should_park(void); 57 bool kthread_freezable_should_stop(bool *was_frozen); 58 void *kthread_data(struct task_struct *k); 59 void *kthread_probe_data(struct task_struct *k); 60 int kthread_park(struct task_struct *k); 61 void kthread_unpark(struct task_struct *k); 62 void kthread_parkme(void); 63 64 int kthreadd(void *unused); 65 extern struct task_struct *kthreadd_task; 66 extern int tsk_fork_get_node(struct task_struct *tsk); 67 68 /* 69 * Simple work processor based on kthread. 70 * 71 * This provides easier way to make use of kthreads. A kthread_work 72 * can be queued and flushed using queue/kthread_flush_work() 73 * respectively. Queued kthread_works are processed by a kthread 74 * running kthread_worker_fn(). 75 */ 76 struct kthread_work; 77 typedef void (*kthread_work_func_t)(struct kthread_work *work); 78 void kthread_delayed_work_timer_fn(unsigned long __data); 79 80 enum { 81 KTW_FREEZABLE = 1 << 0, /* freeze during suspend */ 82 }; 83 84 struct kthread_worker { 85 unsigned int flags; 86 spinlock_t lock; 87 struct list_head work_list; 88 struct list_head delayed_work_list; 89 struct task_struct *task; 90 struct kthread_work *current_work; 91 }; 92 93 struct kthread_work { 94 struct list_head node; 95 kthread_work_func_t func; 96 struct kthread_worker *worker; 97 /* Number of canceling calls that are running at the moment. */ 98 int canceling; 99 }; 100 101 struct kthread_delayed_work { 102 struct kthread_work work; 103 struct timer_list timer; 104 }; 105 106 #define KTHREAD_WORKER_INIT(worker) { \ 107 .lock = __SPIN_LOCK_UNLOCKED((worker).lock), \ 108 .work_list = LIST_HEAD_INIT((worker).work_list), \ 109 .delayed_work_list = LIST_HEAD_INIT((worker).delayed_work_list),\ 110 } 111 112 #define KTHREAD_WORK_INIT(work, fn) { \ 113 .node = LIST_HEAD_INIT((work).node), \ 114 .func = (fn), \ 115 } 116 117 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \ 118 .work = KTHREAD_WORK_INIT((dwork).work, (fn)), \ 119 .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn, \ 120 0, (unsigned long)&(dwork), \ 121 TIMER_IRQSAFE), \ 122 } 123 124 #define DEFINE_KTHREAD_WORKER(worker) \ 125 struct kthread_worker worker = KTHREAD_WORKER_INIT(worker) 126 127 #define DEFINE_KTHREAD_WORK(work, fn) \ 128 struct kthread_work work = KTHREAD_WORK_INIT(work, fn) 129 130 #define DEFINE_KTHREAD_DELAYED_WORK(dwork, fn) \ 131 struct kthread_delayed_work dwork = \ 132 KTHREAD_DELAYED_WORK_INIT(dwork, fn) 133 134 /* 135 * kthread_worker.lock needs its own lockdep class key when defined on 136 * stack with lockdep enabled. Use the following macros in such cases. 137 */ 138 #ifdef CONFIG_LOCKDEP 139 # define KTHREAD_WORKER_INIT_ONSTACK(worker) \ 140 ({ kthread_init_worker(&worker); worker; }) 141 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) \ 142 struct kthread_worker worker = KTHREAD_WORKER_INIT_ONSTACK(worker) 143 #else 144 # define DEFINE_KTHREAD_WORKER_ONSTACK(worker) DEFINE_KTHREAD_WORKER(worker) 145 #endif 146 147 extern void __kthread_init_worker(struct kthread_worker *worker, 148 const char *name, struct lock_class_key *key); 149 150 #define kthread_init_worker(worker) \ 151 do { \ 152 static struct lock_class_key __key; \ 153 __kthread_init_worker((worker), "("#worker")->lock", &__key); \ 154 } while (0) 155 156 #define kthread_init_work(work, fn) \ 157 do { \ 158 memset((work), 0, sizeof(struct kthread_work)); \ 159 INIT_LIST_HEAD(&(work)->node); \ 160 (work)->func = (fn); \ 161 } while (0) 162 163 #define kthread_init_delayed_work(dwork, fn) \ 164 do { \ 165 kthread_init_work(&(dwork)->work, (fn)); \ 166 __setup_timer(&(dwork)->timer, \ 167 kthread_delayed_work_timer_fn, \ 168 (unsigned long)(dwork), \ 169 TIMER_IRQSAFE); \ 170 } while (0) 171 172 int kthread_worker_fn(void *worker_ptr); 173 174 __printf(2, 3) 175 struct kthread_worker * 176 kthread_create_worker(unsigned int flags, const char namefmt[], ...); 177 178 __printf(3, 4) struct kthread_worker * 179 kthread_create_worker_on_cpu(int cpu, unsigned int flags, 180 const char namefmt[], ...); 181 182 bool kthread_queue_work(struct kthread_worker *worker, 183 struct kthread_work *work); 184 185 bool kthread_queue_delayed_work(struct kthread_worker *worker, 186 struct kthread_delayed_work *dwork, 187 unsigned long delay); 188 189 bool kthread_mod_delayed_work(struct kthread_worker *worker, 190 struct kthread_delayed_work *dwork, 191 unsigned long delay); 192 193 void kthread_flush_work(struct kthread_work *work); 194 void kthread_flush_worker(struct kthread_worker *worker); 195 196 bool kthread_cancel_work_sync(struct kthread_work *work); 197 bool kthread_cancel_delayed_work_sync(struct kthread_delayed_work *work); 198 199 void kthread_destroy_worker(struct kthread_worker *worker); 200 201 #endif /* _LINUX_KTHREAD_H */ 202