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()
309  * hwspin_lock_bust() - bust a specific hwspinlock
310  * @hwlock: a previously-acquired hwspinlock which we want to bust
313  * This function will bust a hwspinlock that was previously acquired as
318  * Returns: 0 on success, or -EINVAL if the hwspinlock does not exist, or
320  * defined for the hwspinlock.
322 int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id)  in hwspin_lock_bust()
340  * This is a simple translation function, suitable for hwspinlock platform
360  * This function provides a means for DT users of the hwspinlock module to
361  * get the global lock id of a specific hwspinlock using the phandle of the
362  * hwspinlock device, so that it can be requested using the normal
366  * hwspinlock device is not yet registered, -EINVAL on invalid args
373 	struct hwspinlock *hwlock;  in of_hwspin_lock_get_id()
389 	/* Find the hwspinlock device: we need its base_id */  in of_hwspin_lock_get_id()
428  * This function provides a means for DT users of the hwspinlock module to
429  * get the global lock id of a specific hwspinlock using the specified name of
430  * the hwspinlock device, so that it can be requested using the normal
434  * hwspinlock device is not yet registered, -EINVAL on invalid args
453 static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id)  in hwspin_lock_register_single()
455 	struct hwspinlock *tmp;  in hwspin_lock_register_single()
463 			pr_err("hwspinlock id %d already exists!\n", id);  in hwspin_lock_register_single()
467 	/* mark this hwspinlock as available */  in hwspin_lock_register_single()
478 static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id)  in hwspin_lock_unregister_single()
480 	struct hwspinlock *hwlock = NULL;  in hwspin_lock_unregister_single()
485 	/* make sure the hwspinlock is not in use (tag is set) */  in hwspin_lock_unregister_single()
488 		pr_err("hwspinlock %d still in use (or not present)\n", id);  in hwspin_lock_unregister_single()
494 		pr_err("failed to delete hwspinlock %d\n", id);  in hwspin_lock_unregister_single()
505  * @bank: the hwspinlock device, which usually provides numerous hw locks
507  * @ops: hwspinlock handlers for this device
512  * implementation, to register a new hwspinlock device instance.
521 	struct hwspinlock *hwlock;  in hwspin_lock_register()
557  * @bank: the hwspinlock device, which usually provides numerous hw locks
560  * implementation, to unregister an existing (and unused) hwspinlock.
568 	struct hwspinlock *hwlock, *tmp;  in hwspin_lock_unregister()
606  * @bank: the hwspinlock device, which usually provides numerous hw locks
609  * implementation, to unregister an existing (and unused) hwspinlock.
632  * @bank: the hwspinlock device, which usually provides numerous hw locks
633  * @ops: hwspinlock handlers for this device
638  * implementation, to register a new hwspinlock device instance.
669  * __hwspin_lock_request() - tag an hwspinlock as used and power it up
670  * @hwlock: the target hwspinlock
672  * This is an internal function that prepares an hwspinlock instance
679 static int __hwspin_lock_request(struct hwspinlock *hwlock)  in __hwspin_lock_request()
682 	struct hwspinlock *tmp;  in __hwspin_lock_request()
702 	/* mark hwspinlock as used, should not fail */  in __hwspin_lock_request()
713  * hwspin_lock_get_id() - retrieve id number of a given hwspinlock
714  * @hwlock: a valid hwspinlock instance
718 int hwspin_lock_get_id(struct hwspinlock *hwlock)  in hwspin_lock_get_id()
730  * hwspin_lock_request() - request an hwspinlock
732  * This function should be called by users of the hwspinlock device,
733  * in order to dynamically assign them an unused hwspinlock.
740  * Returns: the address of the assigned hwspinlock, or %NULL on error
742 struct hwspinlock *hwspin_lock_request(void)  in hwspin_lock_request()
744 	struct hwspinlock *hwlock;  in hwspin_lock_request()
753 		pr_warn("a free hwspinlock is not available\n");  in hwspin_lock_request()
773  * hwspin_lock_request_specific() - request for a specific hwspinlock
774  * @id: index of the specific hwspinlock that is requested
776  * This function should be called by users of the hwspinlock module,
777  * in order to assign them a specific hwspinlock.
779  * reserve specific hwspinlock ids for predefined purposes.
783  * Returns: the address of the assigned hwspinlock, or %NULL on error
785 struct hwspinlock *hwspin_lock_request_specific(unsigned int id)  in hwspin_lock_request_specific()
787 	struct hwspinlock *hwlock;  in hwspin_lock_request_specific()
792 	/* make sure this hwspinlock exists */  in hwspin_lock_request_specific()
795 		pr_warn("hwspinlock %u does not exist\n", id);  in hwspin_lock_request_specific()
802 	/* make sure this hwspinlock is unused */  in hwspin_lock_request_specific()
805 		pr_warn("hwspinlock %u is already in use\n", id);  in hwspin_lock_request_specific()
822  * hwspin_lock_free() - free a specific hwspinlock
823  * @hwlock: the specific hwspinlock to free
833 int hwspin_lock_free(struct hwspinlock *hwlock)  in hwspin_lock_free()
836 	struct hwspinlock *tmp;  in hwspin_lock_free()
847 	/* make sure the hwspinlock is used */  in hwspin_lock_free()
860 	/* mark this hwspinlock as available */  in hwspin_lock_free()
877 	struct hwspinlock **hwlock = res;  in devm_hwspin_lock_match()
887 	hwspin_lock_free(*(struct hwspinlock **)res);  in devm_hwspin_lock_release()
891  * devm_hwspin_lock_free() - free a specific hwspinlock for a managed device
892  * @dev: the device to free the specific hwspinlock
893  * @hwlock: the specific hwspinlock to free
903 int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock)  in devm_hwspin_lock_free()
916  * devm_hwspin_lock_request() - request an hwspinlock for a managed device
917  * @dev: the device to request an hwspinlock
919  * This function should be called by users of the hwspinlock device,
920  * in order to dynamically assign them an unused hwspinlock.
927  * Returns: the address of the assigned hwspinlock, or %NULL on error
929 struct hwspinlock *devm_hwspin_lock_request(struct device *dev)  in devm_hwspin_lock_request()
931 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request()
950  * devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
952  * @dev: the device to request the specific hwspinlock
953  * @id: index of the specific hwspinlock that is requested
955  * This function should be called by users of the hwspinlock module,
956  * in order to assign them a specific hwspinlock.
958  * reserve specific hwspinlock ids for predefined purposes.
962  * Returns: the address of the assigned hwspinlock, or %NULL on error
964 struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,  in devm_hwspin_lock_request_specific()
967 	struct hwspinlock **ptr, *hwlock;  in devm_hwspin_lock_request_specific()