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.
91 int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags)  in __hwspin_trylock()
102 	 *    in which the hwspinlock is taken. This is important in order  in __hwspin_trylock()
105 	 * 2. Make the hwspinlock SMP-safe (so we can take it from  in __hwspin_trylock()
108 	 *    problems with hwspinlock usage (e.g. scheduler checks like  in __hwspin_trylock()
131 	/* try to take the hwspinlock device */  in __hwspin_trylock()
158 	 * the hwspinlock, and we must make sure that subsequent memory  in __hwspin_trylock()
160 	 * we actually took the hwspinlock.  in __hwspin_trylock()
172  * __hwspin_lock_timeout() - lock an hwspinlock with timeout limit
173  * @hwlock: the hwspinlock to be locked
193  * so the caller must not sleep, and is advised to release the hwspinlock as
206 int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to,  in __hwspin_lock_timeout()
215 		/* Try to take the hwspinlock */  in __hwspin_lock_timeout()
247  * __hwspin_unlock() - unlock a specific hwspinlock
248  * @hwlock: a previously-acquired hwspinlock which we want to unlock
252  * This function will unlock a specific hwspinlock, enable preemption and
265 void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags)  in __hwspin_unlock()
272 	 * done before unlocking the hwspinlock, will not be reordered  in __hwspin_unlock()
279 	 * take the hwspinlock, and by then we want to be sure our memory  in __hwspin_unlock()
307  * @bank: the hwspinlock device bank
310  * This is a simple translation function, suitable for hwspinlock platform
330  * This function provides a means for DT users of the hwspinlock module to
331  * get the global lock id of a specific hwspinlock using the phandle of the
332  * hwspinlock device, so that it can be requested using the normal
335  * Returns the global lock id number on success, -EPROBE_DEFER if the hwspinlock
342 	struct hwspinlock *hwlock;  in of_hwspin_lock_get_id()
358 	/* Find the hwspinlock device: we need its base_id */  in of_hwspin_lock_get_id()
397  * This function provides a means for DT users of the hwspinlock module to
398  * get the global lock id of a specific hwspinlock using the specified name of
399  * the hwspinlock device, so that it can be requested using the normal
402  * Returns the global lock id number on success, -EPROBE_DEFER if the hwspinlock
421 static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id)  in hwspin_lock_register_single()
423 	struct hwspinlock *tmp;  in hwspin_lock_register_single()
431 			pr_err("hwspinlock id %d already exists!\n", id);  in hwspin_lock_register_single()
435 	/* mark this hwspinlock as available */  in hwspin_lock_register_single()
446 static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)  in hwspin_lock_unregister_single()
448 	struct hwspinlock *hwlock = NULL;  in hwspin_lock_unregister_single()
453 	/* make sure the hwspinlock is not in use (tag is set) */  in hwspin_lock_unregister_single()
456 		pr_err("hwspinlock %d still in use (or not present)\n", id);  in hwspin_lock_unregister_single()
462 		pr_err("failed to delete hwspinlock %d\n", id);  in hwspin_lock_unregister_single()
473  * @bank: the hwspinlock device, which usually provides numerous hw locks
475  * @ops: hwspinlock handlers for this device
480  * implementation, to register a new hwspinlock device instance.
489 	struct hwspinlock *hwlock;  in hwspin_lock_register()
525  * @bank: the hwspinlock device, which usually provides numerous hw locks
528  * implementation, to unregister an existing (and unused) hwspinlock.
536 	struct hwspinlock *hwlock, *tmp;  in hwspin_lock_unregister()
574  * @bank: the hwspinlock device, which usually provides numerous hw locks
577  * implementation, to unregister an existing (and unused) hwspinlock.
600  * @bank: the hwspinlock device, which usually provides numerous hw locks
601  * @ops: hwspinlock handlers for this device
606  * implementation, to register a new hwspinlock device instance.
637  * __hwspin_lock_request() - tag an hwspinlock as used and power it up
639  * This is an internal function that prepares an hwspinlock instance
646 static int __hwspin_lock_request(struct hwspinlock *hwlock)  in __hwspin_lock_request()
649 	struct hwspinlock *tmp;  in __hwspin_lock_request()
669 	/* mark hwspinlock as used, should not fail */  in __hwspin_lock_request()
680  * hwspin_lock_get_id() - retrieve id number of a given hwspinlock
681  * @hwlock: a valid hwspinlock instance
685 int hwspin_lock_get_id(struct hwspinlock *hwlock)  in hwspin_lock_get_id()
697  * hwspin_lock_request() - request an hwspinlock
699  * This function should be called by users of the hwspinlock device,
700  * in order to dynamically assign them an unused hwspinlock.
707  * Returns the address of the assigned hwspinlock, or NULL on error
709 struct hwspinlock *hwspin_lock_request(void)  in hwspin_lock_request()
711 	struct hwspinlock *hwlock;  in hwspin_lock_request()
720 		pr_warn("a free hwspinlock is not available\n");  in hwspin_lock_request()
740  * hwspin_lock_request_specific() - request for a specific hwspinlock
741  * @id: index of the specific hwspinlock that is requested
743  * This function should be called by users of the hwspinlock module,
744  * in order to assign them a specific hwspinlock.
746  * reserve specific hwspinlock ids for predefined purposes.
750  * Returns the address of the assigned hwspinlock, or NULL on error
752 struct hwspinlock *hwspin_lock_request_specific(unsigned int id)  in hwspin_lock_request_specific()
754 	struct hwspinlock *hwlock;  in hwspin_lock_request_specific()
759 	/* make sure this hwspinlock exists */  in hwspin_lock_request_specific()
762 		pr_warn("hwspinlock %u does not exist\n", id);  in hwspin_lock_request_specific()
769 	/* make sure this hwspinlock is unused */  in hwspin_lock_request_specific()
772 		pr_warn("hwspinlock %u is already in use\n", id);  in hwspin_lock_request_specific()
789  * hwspin_lock_free() - free a specific hwspinlock
790  * @hwlock: the specific hwspinlock to free
800 int hwspin_lock_free(struct hwspinlock *hwlock)  in hwspin_lock_free()
803 	struct hwspinlock *tmp;  in hwspin_lock_free()
814 	/* make sure the hwspinlock is used */  in hwspin_lock_free()
827 	/* mark this hwspinlock as available */  in hwspin_lock_free()
844 	struct hwspinlock **hwlock = res;  in devm_hwspin_lock_match()
854 	hwspin_lock_free(*(struct hwspinlock **)res);  in devm_hwspin_lock_release()
858  * devm_hwspin_lock_free() - free a specific hwspinlock for a managed device
859  * @dev: the device to free the specific hwspinlock
860  * @hwlock: the specific hwspinlock to free
870 int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock)  in devm_hwspin_lock_free()
883  * devm_hwspin_lock_request() - request an hwspinlock for a managed device
884  * @dev: the device to request an hwspinlock
886  * This function should be called by users of the hwspinlock device,
887  * in order to dynamically assign them an unused hwspinlock.
894  * Returns the address of the assigned hwspinlock, or NULL on error
896 struct hwspinlock *devm_hwspin_lock_request(struct device *dev)  in devm_hwspin_lock_request()
898 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request()
917  * devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
919  * @dev: the device to request the specific hwspinlock
920  * @id: index of the specific hwspinlock that is requested
922  * This function should be called by users of the hwspinlock module,
923  * in order to assign them a specific hwspinlock.
925  * reserve specific hwspinlock ids for predefined purposes.
929  * Returns the address of the assigned hwspinlock, or NULL on error
931 struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,  in devm_hwspin_lock_request_specific()
934 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request_specific()