1 // SPDX-License-Identifier: GPL-2.0
5  * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
7  * Contact: Ohad Ben-Cohen <ohad@wizery.com>
19 #include <linux/radix-tree.h>
36  * and provides easy-to-use API which makes the hwspinlock core code simple
54  * as the radix-tree API requires that users provide all synchronisation.
55  * A mutex is needed because we're using non-atomic radix tree allocations.
61  * __hwspin_trylock() - attempt to lock a specific hwspinlock
72  * user need some time-consuming or sleepable operations under the hardware
87  * Returns 0 if we successfully locked the hwspinlock or -EBUSY if
96 		return -EINVAL;  in __hwspin_trylock()
105 	 * 2. Make the hwspinlock SMP-safe (so we can take it from  in __hwspin_trylock()
113 		ret = spin_trylock_irqsave(&hwlock->lock, *flags);  in __hwspin_trylock()
116 		ret = spin_trylock_irq(&hwlock->lock);  in __hwspin_trylock()
123 		ret = spin_trylock(&hwlock->lock);  in __hwspin_trylock()
129 		return -EBUSY;  in __hwspin_trylock()
131 	/* try to take the hwspinlock device */  in __hwspin_trylock()
132 	ret = hwlock->bank->ops->trylock(hwlock);  in __hwspin_trylock()
138 			spin_unlock_irqrestore(&hwlock->lock, *flags);  in __hwspin_trylock()
141 			spin_unlock_irq(&hwlock->lock);  in __hwspin_trylock()
148 			spin_unlock(&hwlock->lock);  in __hwspin_trylock()
152 		return -EBUSY;  in __hwspin_trylock()
172  * __hwspin_lock_timeout() - lock an hwspinlock with timeout limit
185  * user need some time-consuming or sleepable operations under the hardware
189  * is handled with busy-waiting delays, hence shall not exceed few msecs.
203  * error code otherwise (most notably -ETIMEDOUT if the @hwlock is still
217 		if (ret != -EBUSY)  in __hwspin_lock_timeout()
228 				return -ETIMEDOUT;  in __hwspin_lock_timeout()
231 				return -ETIMEDOUT;  in __hwspin_lock_timeout()
235 		 * Allow platform-specific relax handlers to prevent  in __hwspin_lock_timeout()
238 		if (hwlock->bank->ops->relax)  in __hwspin_lock_timeout()
239 			hwlock->bank->ops->relax(hwlock);  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
284 	hwlock->bank->ops->unlock(hwlock);  in __hwspin_unlock()
289 		spin_unlock_irqrestore(&hwlock->lock, *flags);  in __hwspin_unlock()
292 		spin_unlock_irq(&hwlock->lock);  in __hwspin_unlock()
299 		spin_unlock(&hwlock->lock);  in __hwspin_unlock()
306  * of_hwspin_lock_simple_xlate - translate hwlock_spec to return a lock id
307  * @bank: the hwspinlock device bank
308  * @hwlock_spec: hwlock specifier as found in the device tree
314  * or -EINVAL on invalid specifier cell count.
319 	if (WARN_ON(hwlock_spec->args_count != 1))  in of_hwspin_lock_simple_xlate()
320 		return -EINVAL;  in of_hwspin_lock_simple_xlate()
322 	return hwlock_spec->args[0];  in of_hwspin_lock_simple_xlate()
326  * of_hwspin_lock_get_id() - get lock id for an OF phandle-based specific lock
327  * @np: device node from which to request the specific hwlock
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
336  * device is not yet registered, -EINVAL on invalid args specifier value or an
348 	ret = of_parse_phandle_with_args(np, "hwlocks", "#hwlock-cells", index,  in of_hwspin_lock_get_id()
354 		ret = -ENOENT;  in of_hwspin_lock_get_id()
358 	/* Find the hwspinlock device: we need its base_id */  in of_hwspin_lock_get_id()
359 	ret = -EPROBE_DEFER;  in of_hwspin_lock_get_id()
370 		if (hwlock->bank->dev->of_node == args.np) {  in of_hwspin_lock_get_id()
380 	if (id < 0 || id >= hwlock->bank->num_locks) {  in of_hwspin_lock_get_id()
381 		ret = -EINVAL;  in of_hwspin_lock_get_id()
384 	id += hwlock->bank->base_id;  in of_hwspin_lock_get_id()
393  * of_hwspin_lock_get_id_byname() - get lock id for an specified hwlock name
394  * @np: device node from which to request the specific hwlock
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
403  * device is not yet registered, -EINVAL on invalid args specifier value or an
411 		return -EINVAL;  in of_hwspin_lock_get_id_byname()
413 	index = of_property_match_string(np, "hwlock-names", name);  in of_hwspin_lock_get_id_byname()
430 		if (ret == -EEXIST)  in hwspin_lock_register_single()
438 	/* self-sanity check which should never fail */  in hwspin_lock_register_single()
472  * hwspin_lock_register() - register a new hw spinlock device
473  * @bank: the hwspinlock device, which usually provides numerous hw locks
474  * @dev: the backing device
475  * @ops: hwspinlock handlers for this device
477  * @num_locks: number of hwspinlocks provided by this device
479  * This function should be called from the underlying platform-specific
480  * implementation, to register a new hwspinlock device instance.
486 int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,  in hwspin_lock_register()
492 	if (!bank || !ops || !dev || !num_locks || !ops->trylock ||  in hwspin_lock_register()
493 							!ops->unlock) {  in hwspin_lock_register()
495 		return -EINVAL;  in hwspin_lock_register()
498 	bank->dev = dev;  in hwspin_lock_register()
499 	bank->ops = ops;  in hwspin_lock_register()
500 	bank->base_id = base_id;  in hwspin_lock_register()
501 	bank->num_locks = num_locks;  in hwspin_lock_register()
504 		hwlock = &bank->lock[i];  in hwspin_lock_register()
506 		spin_lock_init(&hwlock->lock);  in hwspin_lock_register()
507 		hwlock->bank = bank;  in hwspin_lock_register()
517 	while (--i >= 0)  in hwspin_lock_register()
524  * hwspin_lock_unregister() - unregister an hw spinlock device
525  * @bank: the hwspinlock device, which usually provides numerous hw locks
527  * This function should be called from the underlying platform-specific
539 	for (i = 0; i < bank->num_locks; i++) {  in hwspin_lock_unregister()
540 		hwlock = &bank->lock[i];  in hwspin_lock_unregister()
542 		tmp = hwspin_lock_unregister_single(bank->base_id + i);  in hwspin_lock_unregister()
544 			return -EBUSY;  in hwspin_lock_unregister()
546 		/* self-sanity check that should never fail */  in hwspin_lock_unregister()
554 static void devm_hwspin_lock_unreg(struct device *dev, void *res)  in devm_hwspin_lock_unreg()
559 static int devm_hwspin_lock_device_match(struct device *dev, void *res,  in devm_hwspin_lock_device_match()
571  * devm_hwspin_lock_unregister() - unregister an hw spinlock device for
572  *				   a managed device
573  * @dev: the backing device
574  * @bank: the hwspinlock device, which usually provides numerous hw locks
576  * This function should be called from the underlying platform-specific
583 int devm_hwspin_lock_unregister(struct device *dev,  in devm_hwspin_lock_unregister()
597  * devm_hwspin_lock_register() - register a new hw spinlock device for
598  *				 a managed device
599  * @dev: the backing device
600  * @bank: the hwspinlock device, which usually provides numerous hw locks
601  * @ops: hwspinlock handlers for this device
603  * @num_locks: number of hwspinlocks provided by this device
605  * This function should be called from the underlying platform-specific
606  * implementation, to register a new hwspinlock device instance.
612 int devm_hwspin_lock_register(struct device *dev,  in devm_hwspin_lock_register()
622 		return -ENOMEM;  in devm_hwspin_lock_register()
637  * __hwspin_lock_request() - tag an hwspinlock as used and power it up
648 	struct device *dev = hwlock->bank->dev;  in __hwspin_lock_request()
653 	if (!try_module_get(dev->driver->owner)) {  in __hwspin_lock_request()
655 		return -EINVAL;  in __hwspin_lock_request()
660 	if (ret < 0 && ret != -EACCES) {  in __hwspin_lock_request()
661 		dev_err(dev, "%s: can't power on device\n", __func__);  in __hwspin_lock_request()
663 		module_put(dev->driver->owner);  in __hwspin_lock_request()
673 	/* self-sanity check that should never fail */  in __hwspin_lock_request()
680  * hwspin_lock_get_id() - retrieve id number of a given hwspinlock
683  * Returns the id number of a given @hwlock, or -EINVAL if @hwlock is invalid.
689 		return -EINVAL;  in hwspin_lock_get_id()
697  * hwspin_lock_request() - request an hwspinlock
699  * This function should be called by users of the hwspinlock device,
740  * hwspin_lock_request_specific() - request for a specific hwspinlock
741  * @id: index of the specific hwspinlock that is requested
744  * in order to assign them a specific hwspinlock.
746  * reserve specific hwspinlock ids for predefined purposes.
789  * hwspin_lock_free() - free a specific hwspinlock
790  * @hwlock: the specific hwspinlock to free
802 	struct device *dev;  in hwspin_lock_free()
808 		return -EINVAL;  in hwspin_lock_free()
811 	dev = hwlock->bank->dev;  in hwspin_lock_free()
820 		ret = -EINVAL;  in hwspin_lock_free()
824 	/* notify the underlying device that power is not needed */  in hwspin_lock_free()
834 	module_put(dev->driver->owner);  in hwspin_lock_free()
842 static int devm_hwspin_lock_match(struct device *dev, void *res, void *data)  in devm_hwspin_lock_match()
852 static void devm_hwspin_lock_release(struct device *dev, void *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,
896 struct hwspinlock *devm_hwspin_lock_request(struct device *dev)  in devm_hwspin_lock_request()
917  * devm_hwspin_lock_request_specific() - request for a specific hwspinlock for
918  *					 a managed device
919  * @dev: the device to request the specific hwspinlock
920  * @id: index of the specific hwspinlock that is requested
923  * in order to assign them a specific hwspinlock.
925  * reserve specific hwspinlock ids for predefined purposes.
931 struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev,  in devm_hwspin_lock_request_specific()
954 MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");