20 #include <linux/hwspinlock.h>
31 #define HWSPINLOCK_UNUSED	(0) /* tags an hwspinlock as unused */
34  * A radix tree is used to maintain the available hwspinlock instances.
35  * The tree associates hwspinlock pointers with their integer key id,
36  * and provides easy-to-use API which makes the hwspinlock core code simple
42  * used as the ID's of the hwspinlock instances).
45  * framework uses to mark unused hwspinlock instances (see the
47  * tree, looking for an unused hwspinlock instance, is now reduced to a
61  * __hwspin_trylock() - attempt to lock a specific hwspinlock
62  * @hwlock: an hwspinlock which we want to trylock
67  * This function attempts to lock an hwspinlock, and will immediately
68  * fail if the hwspinlock is already taken.
77  * so the caller must not sleep, and is advised to release the hwspinlock as
87  * Returns: %0 if we successfully locked the hwspinlock or -EBUSY if
88  * the hwspinlock was already taken.
92 int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)  in __hwspin_trylock()
103 	 *    in which the hwspinlock is taken. This is important in order  in __hwspin_trylock()
106 	 * 2. Make the hwspinlock SMP-safe (so we can take it from  in __hwspin_trylock()
109 	 *    problems with hwspinlock usage (e.g. scheduler checks like  in __hwspin_trylock()
132 	/* try to take the hwspinlock device */  in __hwspin_trylock()
159 	 * the hwspinlock, and we must make sure that subsequent memory  in __hwspin_trylock()
161 	 * we actually took the hwspinlock.  in __hwspin_trylock()
173  * __hwspin_lock_timeout() - lock an hwspinlock with timeout limit
174  * @hwlock: the hwspinlock to be locked
194  * so the caller must not sleep, and is advised to release the hwspinlock as
209 int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to,  in __hwspin_lock_timeout()
218 		/* Try to take the hwspinlock */  in __hwspin_lock_timeout()
250  * __hwspin_unlock() - unlock a specific hwspinlock
251  * @hwlock: a previously-acquired hwspinlock which we want to unlock
255  * This function will unlock a specific hwspinlock, enable preemption and
268 void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags)  in __hwspin_unlock()
275 	 * done before unlocking the hwspinlock, will not be reordered  in __hwspin_unlock()
282 	 * take the hwspinlock, and by then we want to be sure our memory  in __hwspin_unlock()
312  * This is a simple translation function, suitable for hwspinlock platform
332  * This function provides a means for DT users of the hwspinlock module to
333  * get the global lock id of a specific hwspinlock using the phandle of the
334  * hwspinlock device, so that it can be requested using the normal
338  * hwspinlock device is not yet registered, -EINVAL on invalid args
345 	struct hwspinlock *hwlock;  in of_hwspin_lock_get_id()
361 	/* Find the hwspinlock device: we need its base_id */  in of_hwspin_lock_get_id()
400  * This function provides a means for DT users of the hwspinlock module to
401  * get the global lock id of a specific hwspinlock using the specified name of
402  * the hwspinlock device, so that it can be requested using the normal
406  * hwspinlock device is not yet registered, -EINVAL on invalid args
425 static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id)  in hwspin_lock_register_single()
427 	struct hwspinlock *tmp;  in hwspin_lock_register_single()
435 			pr_err("hwspinlock id %d already exists!\n", id);  in hwspin_lock_register_single()
439 	/* mark this hwspinlock as available */  in hwspin_lock_register_single()
450 static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)  in hwspin_lock_unregister_single()
452 	struct hwspinlock *hwlock = NULL;  in hwspin_lock_unregister_single()
457 	/* make sure the hwspinlock is not in use (tag is set) */  in hwspin_lock_unregister_single()
460 		pr_err("hwspinlock %d still in use (or not present)\n", id);  in hwspin_lock_unregister_single()
466 		pr_err("failed to delete hwspinlock %d\n", id);  in hwspin_lock_unregister_single()
477  * @bank: the hwspinlock device, which usually provides numerous hw locks
479  * @ops: hwspinlock handlers for this device
484  * implementation, to register a new hwspinlock device instance.
493 	struct hwspinlock *hwlock;  in hwspin_lock_register()
529  * @bank: the hwspinlock device, which usually provides numerous hw locks
532  * implementation, to unregister an existing (and unused) hwspinlock.
540 	struct hwspinlock *hwlock, *tmp;  in hwspin_lock_unregister()
578  * @bank: the hwspinlock device, which usually provides numerous hw locks
581  * implementation, to unregister an existing (and unused) hwspinlock.
604  * @bank: the hwspinlock device, which usually provides numerous hw locks
605  * @ops: hwspinlock handlers for this device
610  * implementation, to register a new hwspinlock device instance.
641  * __hwspin_lock_request() - tag an hwspinlock as used and power it up
642  * @hwlock: the target hwspinlock
644  * This is an internal function that prepares an hwspinlock instance
651 static int __hwspin_lock_request(struct hwspinlock *hwlock)  in __hwspin_lock_request()
654 	struct hwspinlock *tmp;  in __hwspin_lock_request()
674 	/* mark hwspinlock as used, should not fail */  in __hwspin_lock_request()
685  * hwspin_lock_get_id() - retrieve id number of a given hwspinlock
686  * @hwlock: a valid hwspinlock instance
690 int hwspin_lock_get_id(struct hwspinlock *hwlock)  in hwspin_lock_get_id()
702  * hwspin_lock_request() - request an hwspinlock
704  * This function should be called by users of the hwspinlock device,
705  * in order to dynamically assign them an unused hwspinlock.
712  * Returns: the address of the assigned hwspinlock, or %NULL on error
714 struct hwspinlock *hwspin_lock_request(void)  in hwspin_lock_request()
716 	struct hwspinlock *hwlock;  in hwspin_lock_request()
725 		pr_warn("a free hwspinlock is not available\n");  in hwspin_lock_request()
745  * hwspin_lock_request_specific() - request for a specific hwspinlock
746  * @id: index of the specific hwspinlock that is requested
748  * This function should be called by users of the hwspinlock module,
749  * in order to assign them a specific hwspinlock.
751  * reserve specific hwspinlock ids for predefined purposes.
755  * Returns: the address of the assigned hwspinlock, or %NULL on error
757 struct hwspinlock *hwspin_lock_request_specific(unsigned int id)  in hwspin_lock_request_specific()
759 	struct hwspinlock *hwlock;  in hwspin_lock_request_specific()
764 	/* make sure this hwspinlock exists */  in hwspin_lock_request_specific()
767 		pr_warn("hwspinlock %u does not exist\n", id);  in hwspin_lock_request_specific()
774 	/* make sure this hwspinlock is unused */  in hwspin_lock_request_specific()
777 		pr_warn("hwspinlock %u is already in use\n", id);  in hwspin_lock_request_specific()
794  * hwspin_lock_free() - free a specific hwspinlock
795  * @hwlock: the specific hwspinlock to free
805 int hwspin_lock_free(struct hwspinlock *hwlock)  in hwspin_lock_free()
808 	struct hwspinlock *tmp;  in hwspin_lock_free()
819 	/* make sure the hwspinlock is used */  in hwspin_lock_free()
832 	/* mark this hwspinlock as available */  in hwspin_lock_free()
849 	struct hwspinlock **hwlock = res;  in devm_hwspin_lock_match()
859 	hwspin_lock_free(*(struct hwspinlock **)res);  in devm_hwspin_lock_release()
863  * devm_hwspin_lock_free() - free a specific hwspinlock for a managed device
864  * @dev: the device to free the specific hwspinlock
865  * @hwlock: the specific hwspinlock to free
875 int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock)  in devm_hwspin_lock_free()
888  * devm_hwspin_lock_request() - request an hwspinlock for a managed device
889  * @dev: the device to request an hwspinlock
891  * This function should be called by users of the hwspinlock device,
892  * in order to dynamically assign them an unused hwspinlock.
899  * Returns: the address of the assigned hwspinlock, or %NULL on error
901 struct hwspinlock *devm_hwspin_lock_request(struct device *dev)  in devm_hwspin_lock_request()
903 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request()
922  * devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
924  * @dev: the device to request the specific hwspinlock
925  * @id: index of the specific hwspinlock that is requested
927  * This function should be called by users of the hwspinlock module,
928  * in order to assign them a specific hwspinlock.
930  * reserve specific hwspinlock ids for predefined purposes.
934  * Returns: the address of the assigned hwspinlock, or %NULL on error
936 struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,  in devm_hwspin_lock_request_specific()
939 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request_specific()