Branch data Line data Source code
1 : : /*
2 : : * Copyright (c) 2016-2017 Wind River Systems, Inc.
3 : : *
4 : : * SPDX-License-Identifier: Apache-2.0
5 : : */
6 : :
7 : : #ifndef ZEPHYR_KERNEL_INCLUDE_KSCHED_H_
8 : : #define ZEPHYR_KERNEL_INCLUDE_KSCHED_H_
9 : :
10 : : #include <zephyr/kernel_structs.h>
11 : : #include <kernel_internal.h>
12 : : #include <timeout_q.h>
13 : : #include <kthread.h>
14 : : #include <zephyr/tracing/tracing.h>
15 : : #include <stdbool.h>
16 : : #include <priority_q.h>
17 : :
18 : : BUILD_ASSERT(K_LOWEST_APPLICATION_THREAD_PRIO
19 : : >= K_HIGHEST_APPLICATION_THREAD_PRIO);
20 : :
21 : : #ifdef CONFIG_MULTITHREADING
22 : : #define Z_VALID_PRIO(prio, entry_point) \
23 : : (((prio) == K_IDLE_PRIO && z_is_idle_thread_entry(entry_point)) || \
24 : : ((K_LOWEST_APPLICATION_THREAD_PRIO \
25 : : >= K_HIGHEST_APPLICATION_THREAD_PRIO) \
26 : : && (prio) >= K_HIGHEST_APPLICATION_THREAD_PRIO \
27 : : && (prio) <= K_LOWEST_APPLICATION_THREAD_PRIO))
28 : :
29 : : #define Z_ASSERT_VALID_PRIO(prio, entry_point) do { \
30 : : __ASSERT(Z_VALID_PRIO((prio), (entry_point)), \
31 : : "invalid priority (%d); allowed range: %d to %d", \
32 : : (prio), \
33 : : K_LOWEST_APPLICATION_THREAD_PRIO, \
34 : : K_HIGHEST_APPLICATION_THREAD_PRIO); \
35 : : } while (false)
36 : : #else
37 : : #define Z_VALID_PRIO(prio, entry_point) ((prio) == -1)
38 : : #define Z_ASSERT_VALID_PRIO(prio, entry_point) __ASSERT((prio) == -1, "")
39 : : #endif /* CONFIG_MULTITHREADING */
40 : :
41 : : #if (CONFIG_MP_MAX_NUM_CPUS == 1)
42 : : #define LOCK_SCHED_SPINLOCK
43 : : #else
44 : : #define LOCK_SCHED_SPINLOCK K_SPINLOCK(&_sched_spinlock)
45 : : #endif
46 : :
47 : : extern struct k_spinlock _sched_spinlock;
48 : :
49 : : extern struct k_thread _thread_dummy;
50 : :
51 : : void z_sched_init(void);
52 : : void z_move_thread_to_end_of_prio_q(struct k_thread *thread);
53 : : void z_unpend_thread_no_timeout(struct k_thread *thread);
54 : : struct k_thread *z_unpend1_no_timeout(_wait_q_t *wait_q);
55 : : int z_pend_curr(struct k_spinlock *lock, k_spinlock_key_t key,
56 : : _wait_q_t *wait_q, k_timeout_t timeout);
57 : : void z_pend_thread(struct k_thread *thread, _wait_q_t *wait_q,
58 : : k_timeout_t timeout);
59 : : void z_reschedule(struct k_spinlock *lock, k_spinlock_key_t key);
60 : : void z_reschedule_irqlock(uint32_t key);
61 : : void z_unpend_thread(struct k_thread *thread);
62 : : int z_unpend_all(_wait_q_t *wait_q);
63 : : bool z_thread_prio_set(struct k_thread *thread, int prio);
64 : : void *z_get_next_switch_handle(void *interrupted);
65 : :
66 : : void z_time_slice(void);
67 : : void z_reset_time_slice(struct k_thread *curr);
68 : : void z_sched_ipi(void);
69 : : void z_sched_start(struct k_thread *thread);
70 : : void z_ready_thread(struct k_thread *thread);
71 : : void z_requeue_current(struct k_thread *curr);
72 : : struct k_thread *z_swap_next_thread(void);
73 : : void z_thread_abort(struct k_thread *thread);
74 : : void move_thread_to_end_of_prio_q(struct k_thread *thread);
75 : : bool thread_is_sliceable(struct k_thread *thread);
76 : :
77 : 1 : static inline void z_reschedule_unlocked(void)
78 : : {
79 : 1 : (void) z_reschedule_irqlock(arch_irq_lock());
80 : 1 : }
81 : :
82 : : static inline bool z_is_under_prio_ceiling(int prio)
83 : : {
84 : : return prio >= CONFIG_PRIORITY_CEILING;
85 : : }
86 : :
87 : : static inline int z_get_new_prio_with_ceiling(int prio)
88 : : {
89 : : return z_is_under_prio_ceiling(prio) ? prio : CONFIG_PRIORITY_CEILING;
90 : : }
91 : :
92 : : static inline bool z_is_prio1_higher_than_or_equal_to_prio2(int prio1, int prio2)
93 : : {
94 : : return prio1 <= prio2;
95 : : }
96 : :
97 : : static inline bool z_is_prio_higher_or_equal(int prio1, int prio2)
98 : : {
99 : : return z_is_prio1_higher_than_or_equal_to_prio2(prio1, prio2);
100 : : }
101 : :
102 : : static inline bool z_is_prio1_lower_than_or_equal_to_prio2(int prio1, int prio2)
103 : : {
104 : : return prio1 >= prio2;
105 : : }
106 : :
107 : 0 : static inline bool z_is_prio1_higher_than_prio2(int prio1, int prio2)
108 : : {
109 : 0 : return prio1 < prio2;
110 : : }
111 : :
112 : 0 : static inline bool z_is_prio_higher(int prio, int test_prio)
113 : : {
114 : 0 : return z_is_prio1_higher_than_prio2(prio, test_prio);
115 : : }
116 : :
117 : : static inline bool z_is_prio_lower_or_equal(int prio1, int prio2)
118 : : {
119 : : return z_is_prio1_lower_than_or_equal_to_prio2(prio1, prio2);
120 : : }
121 : :
122 : : int32_t z_sched_prio_cmp(struct k_thread *thread_1, struct k_thread *thread_2);
123 : :
124 : : static inline bool _is_valid_prio(int prio, void *entry_point)
125 : : {
126 : : if ((prio == K_IDLE_PRIO) && z_is_idle_thread_entry(entry_point)) {
127 : : return true;
128 : : }
129 : :
130 : : if (!z_is_prio_higher_or_equal(prio,
131 : : K_LOWEST_APPLICATION_THREAD_PRIO)) {
132 : : return false;
133 : : }
134 : :
135 : : if (!z_is_prio_lower_or_equal(prio,
136 : : K_HIGHEST_APPLICATION_THREAD_PRIO)) {
137 : : return false;
138 : : }
139 : :
140 : : return true;
141 : : }
142 : :
143 : 1 : static inline void z_sched_lock(void)
144 : : {
145 [ - + ]: 1 : __ASSERT(!arch_is_in_isr(), "");
146 [ - + ]: 1 : __ASSERT(arch_current_thread()->base.sched_locked != 1U, "");
147 : :
148 : 1 : --arch_current_thread()->base.sched_locked;
149 : :
150 : 1 : compiler_barrier();
151 : 1 : }
152 : :
153 : 10 : static ALWAYS_INLINE _wait_q_t *pended_on_thread(struct k_thread *thread)
154 : : {
155 [ - + ]: 10 : __ASSERT_NO_MSG(thread->base.pended_on);
156 : :
157 : 10 : return thread->base.pended_on;
158 : : }
159 : :
160 : :
161 : 10 : static inline void unpend_thread_no_timeout(struct k_thread *thread)
162 : : {
163 : 10 : _priq_wait_remove(&pended_on_thread(thread)->waitq, thread);
164 : 10 : z_mark_thread_as_not_pending(thread);
165 : 10 : thread->base.pended_on = NULL;
166 : 10 : }
167 : :
168 : : /*
169 : : * In a multiprocessor system, z_unpend_first_thread() must lock the scheduler
170 : : * spinlock _sched_spinlock. However, in a uniprocessor system, that is not
171 : : * necessary as the caller has already taken precautions (in the form of
172 : : * locking interrupts).
173 : : */
174 : 6 : static ALWAYS_INLINE struct k_thread *z_unpend_first_thread(_wait_q_t *wait_q)
175 : : {
176 : 6 : struct k_thread *thread = NULL;
177 : :
178 [ - + ]: 6 : __ASSERT_EVAL(, int key = arch_irq_lock(); arch_irq_unlock(key),
179 : : !arch_irq_unlocked(key), "");
180 : :
181 : : LOCK_SCHED_SPINLOCK {
182 : 6 : thread = _priq_wait_best(&wait_q->waitq);
183 [ + + ]: 6 : if (unlikely(thread != NULL)) {
184 : 4 : unpend_thread_no_timeout(thread);
185 : 4 : (void)z_abort_thread_timeout(thread);
186 : : }
187 : : }
188 : :
189 : 6 : return thread;
190 : : }
191 : :
192 : : /*
193 : : * APIs for working with the Zephyr kernel scheduler. Intended for use in
194 : : * management of IPC objects, either in the core kernel or other IPC
195 : : * implemented by OS compatibility layers, providing basic wait/wake operations
196 : : * with spinlocks used for synchronization.
197 : : *
198 : : * These APIs are public and will be treated as contract, even if the
199 : : * underlying scheduler implementation changes.
200 : : */
201 : :
202 : : /**
203 : : * Wake up a thread pending on the provided wait queue
204 : : *
205 : : * Given a wait_q, wake up the highest priority thread on the queue. If the
206 : : * queue was empty just return false.
207 : : *
208 : : * Otherwise, do the following, in order, holding _sched_spinlock the entire
209 : : * time so that the thread state is guaranteed not to change:
210 : : * - Set the thread's swap return values to swap_retval and swap_data
211 : : * - un-pend and ready the thread, but do not invoke the scheduler.
212 : : *
213 : : * Repeated calls to this function until it returns false is a suitable
214 : : * way to wake all threads on the queue.
215 : : *
216 : : * It is up to the caller to implement locking such that the return value of
217 : : * this function (whether a thread was woken up or not) does not immediately
218 : : * become stale. Calls to wait and wake on the same wait_q object must have
219 : : * synchronization. Calling this without holding any spinlock is a sign that
220 : : * this API is not being used properly.
221 : : *
222 : : * @param wait_q Wait queue to wake up the highest prio thread
223 : : * @param swap_retval Swap return value for woken thread
224 : : * @param swap_data Data return value to supplement swap_retval. May be NULL.
225 : : * @retval true If a thread was woken up
226 : : * @retval false If the wait_q was empty
227 : : */
228 : : bool z_sched_wake(_wait_q_t *wait_q, int swap_retval, void *swap_data);
229 : :
230 : : /**
231 : : * Wakes the specified thread.
232 : : *
233 : : * Given a specific thread, wake it up. This routine assumes that the given
234 : : * thread is not on the timeout queue.
235 : : *
236 : : * @param thread Given thread to wake up.
237 : : * @param is_timeout True if called from the timer ISR; false otherwise.
238 : : *
239 : : */
240 : : void z_sched_wake_thread(struct k_thread *thread, bool is_timeout);
241 : :
242 : : /**
243 : : * Wake up all threads pending on the provided wait queue
244 : : *
245 : : * Convenience function to invoke z_sched_wake() on all threads in the queue
246 : : * until there are no more to wake up.
247 : : *
248 : : * @param wait_q Wait queue to wake up the highest prio thread
249 : : * @param swap_retval Swap return value for woken thread
250 : : * @param swap_data Data return value to supplement swap_retval. May be NULL.
251 : : * @retval true If any threads were woken up
252 : : * @retval false If the wait_q was empty
253 : : */
254 : : static inline bool z_sched_wake_all(_wait_q_t *wait_q, int swap_retval,
255 : : void *swap_data)
256 : : {
257 : : bool woken = false;
258 : :
259 : : while (z_sched_wake(wait_q, swap_retval, swap_data)) {
260 : : woken = true;
261 : : }
262 : :
263 : : /* True if we woke at least one thread up */
264 : : return woken;
265 : : }
266 : :
267 : : /**
268 : : * Atomically put the current thread to sleep on a wait queue, with timeout
269 : : *
270 : : * The thread will be added to the provided waitqueue. The lock, which should
271 : : * be held by the caller with the provided key, will be released once this is
272 : : * completely done and we have swapped out.
273 : : *
274 : : * The return value and data pointer is set by whoever woke us up via
275 : : * z_sched_wake.
276 : : *
277 : : * @param lock Address of spinlock to release when we swap out
278 : : * @param key Key to the provided spinlock when it was locked
279 : : * @param wait_q Wait queue to go to sleep on
280 : : * @param timeout Waiting period to be woken up, or K_FOREVER to wait
281 : : * indefinitely.
282 : : * @param data Storage location for data pointer set when thread was woken up.
283 : : * May be NULL if not used.
284 : : * @retval Return value set by whatever woke us up, or -EAGAIN if the timeout
285 : : * expired without being woken up.
286 : : */
287 : : int z_sched_wait(struct k_spinlock *lock, k_spinlock_key_t key,
288 : : _wait_q_t *wait_q, k_timeout_t timeout, void **data);
289 : :
290 : : /**
291 : : * @brief Walks the wait queue invoking the callback on each waiting thread
292 : : *
293 : : * This function walks the wait queue invoking the callback function on each
294 : : * waiting thread while holding _sched_spinlock. This can be useful for routines
295 : : * that need to operate on multiple waiting threads.
296 : : *
297 : : * CAUTION! As a wait queue is of indeterminate length, the scheduler will be
298 : : * locked for an indeterminate amount of time. This may impact system
299 : : * performance. As such, care must be taken when using both this function and
300 : : * the specified callback.
301 : : *
302 : : * @param wait_q Identifies the wait queue to walk
303 : : * @param func Callback to invoke on each waiting thread
304 : : * @param data Custom data passed to the callback
305 : : *
306 : : * @retval non-zero if walk is terminated by the callback; otherwise 0
307 : : */
308 : : int z_sched_waitq_walk(_wait_q_t *wait_q,
309 : : int (*func)(struct k_thread *, void *), void *data);
310 : :
311 : : /** @brief Halt thread cycle usage accounting.
312 : : *
313 : : * Halts the accumulation of thread cycle usage and adds the current
314 : : * total to the thread's counter. Called on context switch.
315 : : *
316 : : * Note that this function is idempotent. The core kernel code calls
317 : : * it at the end of interrupt handlers (because that is where we have
318 : : * a portable hook) where we are context switching, which will include
319 : : * any cycles spent in the ISR in the per-thread accounting. But
320 : : * architecture code can also call it earlier out of interrupt entry
321 : : * to improve measurement fidelity.
322 : : *
323 : : * This function assumes local interrupts are masked (so that the
324 : : * current CPU pointer and current thread are safe to modify), but
325 : : * requires no other synchronization. Architecture layers don't need
326 : : * to do anything more.
327 : : */
328 : : void z_sched_usage_stop(void);
329 : :
330 : : void z_sched_usage_start(struct k_thread *thread);
331 : :
332 : : /**
333 : : * @brief Retrieves CPU cycle usage data for specified core
334 : : */
335 : : void z_sched_cpu_usage(uint8_t core_id, struct k_thread_runtime_stats *stats);
336 : :
337 : : /**
338 : : * @brief Retrieves thread cycle usage data for specified thread
339 : : */
340 : : void z_sched_thread_usage(struct k_thread *thread,
341 : : struct k_thread_runtime_stats *stats);
342 : :
343 : : static inline void z_sched_usage_switch(struct k_thread *thread)
344 : : {
345 : : ARG_UNUSED(thread);
346 : : #ifdef CONFIG_SCHED_THREAD_USAGE
347 : : z_sched_usage_stop();
348 : : z_sched_usage_start(thread);
349 : : #endif /* CONFIG_SCHED_THREAD_USAGE */
350 : : }
351 : :
352 : : #endif /* ZEPHYR_KERNEL_INCLUDE_KSCHED_H_ */
|
