1 // SPDX-License-Identifier: GPL-2.0
3  * Generic Counter character device interface
7 #include <linux/counter.h>
24 #include "counter-chrdev.h"
68 	struct counter_device *const counter = filp->private_data;  in counter_chrdev_read()  local
72 	if (!counter->ops)  in counter_chrdev_read()
73 		return -ENODEV;  in counter_chrdev_read()
76 		return -EINVAL;  in counter_chrdev_read()
79 		if (kfifo_is_empty(&counter->events)) {  in counter_chrdev_read()
80 			if (filp->f_flags & O_NONBLOCK)  in counter_chrdev_read()
81 				return -EAGAIN;  in counter_chrdev_read()
83 			err = wait_event_interruptible(counter->events_wait,  in counter_chrdev_read()
84 					!kfifo_is_empty(&counter->events) ||  in counter_chrdev_read()
85 					!counter->ops);  in counter_chrdev_read()
86 			if (err < 0)  in counter_chrdev_read()
88 			if (!counter->ops)  in counter_chrdev_read()
89 				return -ENODEV;  in counter_chrdev_read()
92 		if (mutex_lock_interruptible(&counter->events_out_lock))  in counter_chrdev_read()
93 			return -ERESTARTSYS;  in counter_chrdev_read()
94 		err = kfifo_to_user(&counter->events, buf, len, &copied);  in counter_chrdev_read()
95 		mutex_unlock(&counter->events_out_lock);  in counter_chrdev_read()
96 		if (err < 0)  in counter_chrdev_read()
106 	struct counter_device *const counter = filp->private_data;  in counter_chrdev_poll()  local
107 	__poll_t events = 0;  in counter_chrdev_poll()
109 	if (!counter->ops)  in counter_chrdev_poll()
112 	poll_wait(filp, &counter->events_wait, pollt);  in counter_chrdev_poll()
114 	if (!kfifo_is_empty(&counter->events))  in counter_chrdev_poll()
127 		list_for_each_entry_safe(q, o, &p->comp_list, l) {  in counter_events_list_free()
128 			list_del(&q->l);  in counter_events_list_free()
133 		list_del(&p->l);  in counter_events_list_free()
138 static int counter_set_event_node(struct counter_device *const counter,  in counter_set_event_node()  argument
143 	int err = 0;  in counter_set_event_node()
147 	list_for_each_entry(event_node, &counter->next_events_list, l)  in counter_set_event_node()
148 		if (event_node->event == watch->event &&  in counter_set_event_node()
149 		    event_node->channel == watch->channel)  in counter_set_event_node()
153 	if (&event_node->l == &counter->next_events_list) {  in counter_set_event_node()
157 			return -ENOMEM;  in counter_set_event_node()
160 		event_node->event = watch->event;  in counter_set_event_node()
161 		event_node->channel = watch->channel;  in counter_set_event_node()
162 		INIT_LIST_HEAD(&event_node->comp_list);  in counter_set_event_node()
163 		list_add(&event_node->l, &counter->next_events_list);  in counter_set_event_node()
167 	list_for_each_entry(comp_node, &event_node->comp_list, l)  in counter_set_event_node()
168 		if (comp_node->parent == cfg->parent &&  in counter_set_event_node()
169 		    counter_comp_read_is_equal(comp_node->comp, cfg->comp)) {  in counter_set_event_node()
170 			err = -EINVAL;  in counter_set_event_node()
177 		err = -ENOMEM;  in counter_set_event_node()
183 	list_add_tail(&comp_node->l, &event_node->comp_list);  in counter_set_event_node()
187 	if (list_empty(&event_node->comp_list)) {  in counter_set_event_node()
188 		list_del(&event_node->l);  in counter_set_event_node()
195 static int counter_enable_events(struct counter_device *const counter)  in counter_enable_events()  argument
198 	int err = 0;  in counter_enable_events()
200 	mutex_lock(&counter->n_events_list_lock);  in counter_enable_events()
201 	spin_lock_irqsave(&counter->events_list_lock, flags);  in counter_enable_events()
203 	counter_events_list_free(&counter->events_list);  in counter_enable_events()
204 	list_replace_init(&counter->next_events_list,  in counter_enable_events()
205 			  &counter->events_list);  in counter_enable_events()
207 	if (counter->ops->events_configure)  in counter_enable_events()
208 		err = counter->ops->events_configure(counter);  in counter_enable_events()
210 	spin_unlock_irqrestore(&counter->events_list_lock, flags);  in counter_enable_events()
211 	mutex_unlock(&counter->n_events_list_lock);  in counter_enable_events()
216 static int counter_disable_events(struct counter_device *const counter)  in counter_disable_events()  argument
219 	int err = 0;  in counter_disable_events()
221 	spin_lock_irqsave(&counter->events_list_lock, flags);  in counter_disable_events()
223 	counter_events_list_free(&counter->events_list);  in counter_disable_events()
225 	if (counter->ops->events_configure)  in counter_disable_events()
226 		err = counter->ops->events_configure(counter);  in counter_disable_events()
228 	spin_unlock_irqrestore(&counter->events_list_lock, flags);  in counter_disable_events()
230 	mutex_lock(&counter->n_events_list_lock);  in counter_disable_events()
232 	counter_events_list_free(&counter->next_events_list);  in counter_disable_events()
234 	mutex_unlock(&counter->n_events_list_lock);  in counter_disable_events()
245 	*id = 0;  in counter_get_ext()
246 	for (*ext_idx = 0; *ext_idx < num_ext; (*ext_idx)++) {  in counter_get_ext()
248 			return 0;  in counter_get_ext()
250 		if (ext->type == COUNTER_COMP_ARRAY) {  in counter_get_ext()
251 			element = ext->priv;  in counter_get_ext()
253 			if (component_id - *id < element->length)  in counter_get_ext()
254 				return 0;  in counter_get_ext()
256 			*id += element->length;  in counter_get_ext()
261 	return -EINVAL;  in counter_get_ext()
264 static int counter_add_watch(struct counter_device *const counter,  in counter_add_watch()  argument
274 	int err = 0;  in counter_add_watch()
277 		return -EFAULT;  in counter_add_watch()
287 		ext = counter->ext;  in counter_add_watch()
288 		num_ext = counter->num_ext;  in counter_add_watch()
291 		if (parent >= counter->num_signals)  in counter_add_watch()
292 			return -EINVAL;  in counter_add_watch()
293 		parent = array_index_nospec(parent, counter->num_signals);  in counter_add_watch()
295 		comp_node.parent = counter->signals + parent;  in counter_add_watch()
297 		ext = counter->signals[parent].ext;  in counter_add_watch()
298 		num_ext = counter->signals[parent].num_ext;  in counter_add_watch()
301 		if (parent >= counter->num_counts)  in counter_add_watch()
302 			return -EINVAL;  in counter_add_watch()
303 		parent = array_index_nospec(parent, counter->num_counts);  in counter_add_watch()
305 		comp_node.parent = counter->counts + parent;  in counter_add_watch()
307 		ext = counter->counts[parent].ext;  in counter_add_watch()
308 		num_ext = counter->counts[parent].num_ext;  in counter_add_watch()
311 		return -EINVAL;  in counter_add_watch()
320 			return -EINVAL;  in counter_add_watch()
323 		comp_node.comp.signal_u32_read = counter->ops->signal_read;  in counter_add_watch()
327 			return -EINVAL;  in counter_add_watch()
330 		comp_node.comp.count_u64_read = counter->ops->count_read;  in counter_add_watch()
334 			return -EINVAL;  in counter_add_watch()
337 		comp_node.comp.count_u32_read = counter->ops->function_read;  in counter_add_watch()
341 			return -EINVAL;  in counter_add_watch()
342 		if (id >= counter->counts[parent].num_synapses)  in counter_add_watch()
343 			return -EINVAL;  in counter_add_watch()
344 		id = array_index_nospec(id, counter->counts[parent].num_synapses);  in counter_add_watch()
347 		comp_node.comp.action_read = counter->ops->action_read;  in counter_add_watch()
348 		comp_node.comp.priv = counter->counts[parent].synapses + id;  in counter_add_watch()
352 		if (err < 0)  in counter_add_watch()
358 		return -EINVAL;  in counter_add_watch()
361 		return -EOPNOTSUPP;  in counter_add_watch()
364 	mutex_lock(&counter->n_events_list_lock);  in counter_add_watch()
366 	if (counter->ops->watch_validate) {  in counter_add_watch()
367 		err = counter->ops->watch_validate(counter, &watch);  in counter_add_watch()
368 		if (err < 0)  in counter_add_watch()
374 	err = counter_set_event_node(counter, &watch, &comp_node);  in counter_add_watch()
377 	mutex_unlock(&counter->n_events_list_lock);  in counter_add_watch()
385 	struct counter_device *const counter = filp->private_data;  in counter_chrdev_ioctl()  local
386 	int ret = -ENODEV;  in counter_chrdev_ioctl()
388 	mutex_lock(&counter->ops_exist_lock);  in counter_chrdev_ioctl()
390 	if (!counter->ops)  in counter_chrdev_ioctl()
395 		ret = counter_add_watch(counter, arg);  in counter_chrdev_ioctl()
398 		ret = counter_enable_events(counter);  in counter_chrdev_ioctl()
401 		ret = counter_disable_events(counter);  in counter_chrdev_ioctl()
404 		ret = -ENOIOCTLCMD;  in counter_chrdev_ioctl()
409 	mutex_unlock(&counter->ops_exist_lock);  in counter_chrdev_ioctl()
416 	struct counter_device *const counter = container_of(inode->i_cdev,  in counter_chrdev_open()  local
417 							    typeof(*counter),  in counter_chrdev_open()
420 	get_device(&counter->dev);  in counter_chrdev_open()
421 	filp->private_data = counter;  in counter_chrdev_open()
428 	struct counter_device *const counter = filp->private_data;  in counter_chrdev_release()  local
429 	int ret = 0;  in counter_chrdev_release()
431 	mutex_lock(&counter->ops_exist_lock);  in counter_chrdev_release()
433 	if (!counter->ops) {  in counter_chrdev_release()
435 		counter_events_list_free(&counter->events_list);  in counter_chrdev_release()
436 		counter_events_list_free(&counter->next_events_list);  in counter_chrdev_release()
437 		ret = -ENODEV;  in counter_chrdev_release()
441 	ret = counter_disable_events(counter);  in counter_chrdev_release()
442 	if (ret < 0) {  in counter_chrdev_release()
443 		mutex_unlock(&counter->ops_exist_lock);  in counter_chrdev_release()
448 	mutex_unlock(&counter->ops_exist_lock);  in counter_chrdev_release()
450 	put_device(&counter->dev);  in counter_chrdev_release()
465 int counter_chrdev_add(struct counter_device *const counter)  in counter_chrdev_add()  argument
467 	/* Initialize Counter events lists */  in counter_chrdev_add()
468 	INIT_LIST_HEAD(&counter->events_list);  in counter_chrdev_add()
469 	INIT_LIST_HEAD(&counter->next_events_list);  in counter_chrdev_add()
470 	spin_lock_init(&counter->events_list_lock);  in counter_chrdev_add()
471 	mutex_init(&counter->n_events_list_lock);  in counter_chrdev_add()
472 	init_waitqueue_head(&counter->events_wait);  in counter_chrdev_add()
473 	spin_lock_init(&counter->events_in_lock);  in counter_chrdev_add()
474 	mutex_init(&counter->events_out_lock);  in counter_chrdev_add()
477 	cdev_init(&counter->chrdev, &counter_fops);  in counter_chrdev_add()
479 	/* Allocate Counter events queue */  in counter_chrdev_add()
480 	return kfifo_alloc(&counter->events, 64, GFP_KERNEL);  in counter_chrdev_add()
483 void counter_chrdev_remove(struct counter_device *const counter)  in counter_chrdev_remove()  argument
485 	kfifo_free(&counter->events);  in counter_chrdev_remove()
488 static int counter_get_array_data(struct counter_device *const counter,  in counter_get_array_data()  argument
494 	const struct counter_array *const element = comp->priv;  in counter_get_array_data()
495 	u32 value_u32 = 0;  in counter_get_array_data()
498 	switch (element->type) {  in counter_get_array_data()
501 			return -EINVAL;  in counter_get_array_data()
502 		ret = comp->signal_array_u32_read(counter, parent, idx,  in counter_get_array_data()
509 			return comp->device_array_u64_read(counter, idx, value);  in counter_get_array_data()
511 			return comp->signal_array_u64_read(counter, parent, idx,  in counter_get_array_data()
514 			return comp->count_array_u64_read(counter, parent, idx,  in counter_get_array_data()
517 			return -EINVAL;  in counter_get_array_data()
520 		return -EINVAL;  in counter_get_array_data()
524 static int counter_get_data(struct counter_device *const counter,  in counter_get_data()  argument
528 	const struct counter_comp *const comp = &comp_node->comp;  in counter_get_data()
529 	const enum counter_scope scope = comp_node->component.scope;  in counter_get_data()
530 	const size_t id = comp_node->component.id;  in counter_get_data()
531 	struct counter_signal *const signal = comp_node->parent;  in counter_get_data()
532 	struct counter_count *const count = comp_node->parent;  in counter_get_data()
533 	u8 value_u8 = 0;  in counter_get_data()
534 	u32 value_u32 = 0;  in counter_get_data()
540 	if (comp_node->component.type == COUNTER_COMPONENT_NONE)  in counter_get_data()
541 		return 0;  in counter_get_data()
543 	switch (comp->type) {  in counter_get_data()
548 			ret = comp->device_u8_read(counter, &value_u8);  in counter_get_data()
551 			ret = comp->signal_u8_read(counter, signal, &value_u8);  in counter_get_data()
554 			ret = comp->count_u8_read(counter, count, &value_u8);  in counter_get_data()
557 			return -EINVAL;  in counter_get_data()
569 			ret = comp->device_u32_read(counter, &value_u32);  in counter_get_data()
572 			ret = comp->signal_u32_read(counter, signal,  in counter_get_data()
576 			ret = comp->count_u32_read(counter, count, &value_u32);  in counter_get_data()
579 			return -EINVAL;  in counter_get_data()
586 			return comp->device_u64_read(counter, value);  in counter_get_data()
588 			return comp->signal_u64_read(counter, signal, value);  in counter_get_data()
590 			return comp->count_u64_read(counter, count, value);  in counter_get_data()
592 			return -EINVAL;  in counter_get_data()
595 		ret = comp->action_read(counter, count, comp->priv, &value_u32);  in counter_get_data()
601 			ext = counter->ext;  in counter_get_data()
602 			num_ext = counter->num_ext;  in counter_get_data()
605 			ext = signal->ext;  in counter_get_data()
606 			num_ext = signal->num_ext;  in counter_get_data()
609 			ext = count->ext;  in counter_get_data()
610 			num_ext = count->num_ext;  in counter_get_data()
613 			return -EINVAL;  in counter_get_data()
616 		if (ret < 0)  in counter_get_data()
619 		return counter_get_array_data(counter, scope, comp_node->parent,  in counter_get_data()
620 					      comp, id - ext_id, value);  in counter_get_data()
622 		return -EINVAL;  in counter_get_data()
627  * counter_push_event - queue event for userspace reading
628  * @counter:	pointer to Counter structure
635 void counter_push_event(struct counter_device *const counter, const u8 event,  in counter_push_event()  argument
639 	unsigned int copied = 0;  in counter_push_event()
649 	spin_lock_irqsave(&counter->events_list_lock, flags);  in counter_push_event()
652 	list_for_each_entry(event_node, &counter->events_list, l)  in counter_push_event()
653 		if (event_node->event == event &&  in counter_push_event()
654 		    event_node->channel == channel)  in counter_push_event()
658 	if (&event_node->l == &counter->events_list)  in counter_push_event()
662 	list_for_each_entry(comp_node, &event_node->comp_list, l) {  in counter_push_event()
663 		ev.watch.component = comp_node->component;  in counter_push_event()
664 		ev.status = -counter_get_data(counter, comp_node, &ev.value);  in counter_push_event()
666 		copied += kfifo_in_spinlocked_noirqsave(&counter->events, &ev,  in counter_push_event()
667 							1, &counter->events_in_lock);  in counter_push_event()
671 	spin_unlock_irqrestore(&counter->events_list_lock, flags);  in counter_push_event()
674 		wake_up_poll(&counter->events_wait, EPOLLIN);  in counter_push_event()
676 EXPORT_SYMBOL_NS_GPL(counter_push_event, COUNTER);