4  * SPDX-License-Identifier: Apache-2.0
56 	 * - current FIFO tail value is atomically incremented while it's
58 	 * - we spin until the FIFO head becomes equal to the ticket value
108 bool z_spin_lock_valid(struct k_spinlock *l);
109 bool z_spin_unlock_valid(struct k_spinlock *l);
110 void z_spin_lock_set_owner(struct k_spinlock *l);
114 bool z_spin_lock_mem_coherent(struct k_spinlock *l);
132 static ALWAYS_INLINE void z_spinlock_validate_pre(struct k_spinlock *l)  in z_spinlock_validate_pre()  argument
134 	ARG_UNUSED(l);  in z_spinlock_validate_pre()
136 	__ASSERT(z_spin_lock_valid(l), "Invalid spinlock %p", l);  in z_spinlock_validate_pre()
138 	__ASSERT_NO_MSG(z_spin_lock_mem_coherent(l));  in z_spinlock_validate_pre()
143 static ALWAYS_INLINE void z_spinlock_validate_post(struct k_spinlock *l)  in z_spinlock_validate_post()  argument
145 	ARG_UNUSED(l);  in z_spinlock_validate_post()
147 	z_spin_lock_set_owner(l);  in z_spinlock_validate_post()
149 	l->lock_time = sys_clock_cycle_get_32();  in z_spinlock_validate_post()
164  * implementation-defined busy loop ("spinning") until the lock is
178  * @param l A pointer to the spinlock to lock
182 static ALWAYS_INLINE k_spinlock_key_t k_spin_lock(struct k_spinlock *l)  in k_spin_lock()  argument
184 	ARG_UNUSED(l);  in k_spin_lock()
187 	/* Note that we need to use the underlying arch-specific lock  in k_spin_lock()
193 	z_spinlock_validate_pre(l);  in k_spin_lock()
200 	atomic_val_t ticket = atomic_inc(&l->tail);  in k_spin_lock()
202 	while (atomic_get(&l->owner) != ticket) {  in k_spin_lock()
206 	while (!atomic_cas(&l->locked, 0, 1)) {  in k_spin_lock()
211 	z_spinlock_validate_post(l);  in k_spin_lock()
219  * This routine makes one attempt to lock @p l. If it is successful, then
222  * @param[in] l A pointer to the spinlock to lock
225  * @retval -EBUSY if another thread holds the lock
230 static ALWAYS_INLINE int k_spin_trylock(struct k_spinlock *l, k_spinlock_key_t *k)  in k_spin_trylock()  argument
234 	z_spinlock_validate_pre(l);  in k_spin_trylock()
244 	 * - spinlock needs to be taken 0xffff_..._ffff + 1 times  in k_spin_trylock()
247 	 * - spinlock needs to be taken and released 0xffff_..._ffff times and  in k_spin_trylock()
250 	 * In real-life systems this is considered non-reproducible given that  in k_spin_trylock()
255 	atomic_val_t ticket_val = atomic_get(&l->owner);  in k_spin_trylock()
257 	if (!atomic_cas(&l->tail, ticket_val, ticket_val + 1)) {  in k_spin_trylock()
261 	if (!atomic_cas(&l->locked, 0, 1)) {  in k_spin_trylock()
266 	z_spinlock_validate_post(l);  in k_spin_trylock()
268 	k->key = key;  in k_spin_trylock()
275 	return -EBUSY;  in k_spin_trylock()
291  * unlock mis-nested locks, or to unlock locks that are not held, or
296  * @param l A pointer to the spinlock to release
300 static ALWAYS_INLINE void k_spin_unlock(struct k_spinlock *l,  in k_spin_unlock()  argument
303 	ARG_UNUSED(l);  in k_spin_unlock()
305 	__ASSERT(z_spin_unlock_valid(l), "Not my spinlock %p", l);  in k_spin_unlock()
308 	uint32_t delta = sys_clock_cycle_get_32() - l->lock_time;  in k_spin_unlock()
312 		 l, delta, CONFIG_SPIN_LOCK_TIME_LIMIT);  in k_spin_unlock()
319 	(void)atomic_inc(&l->owner);  in k_spin_unlock()
328 	(void)atomic_clear(&l->locked);  in k_spin_unlock()
343  * @param l A pointer to the spinlock
344  * @retval true - if spinlock is held by some CPU; false - otherwise
346 static ALWAYS_INLINE bool z_spin_is_locked(struct k_spinlock *l)  in z_spin_is_locked()  argument
349 	atomic_val_t ticket_val = atomic_get(&l->owner);  in z_spin_is_locked()
351 	return !atomic_cas(&l->tail, ticket_val, ticket_val);  in z_spin_is_locked()
353 	return l->locked;  in z_spin_is_locked()
359 static ALWAYS_INLINE void k_spin_release(struct k_spinlock *l)  in k_spin_release()  argument
361 	ARG_UNUSED(l);  in k_spin_release()
363 	__ASSERT(z_spin_unlock_valid(l), "Not my spinlock %p", l);  in k_spin_release()
367 	(void)atomic_inc(&l->owner);  in k_spin_release()
369 	(void)atomic_clear(&l->locked);  in k_spin_release()
377 	__ASSERT(k->key, "K_SPINLOCK exited with goto, break or return, "  in z_spin_onexit()
420  * Behind the scenes this pattern expands to a for-loop whose body is executed