xref: /linux/drivers/misc/mei/client.c (revision 26ec99b105d5d1465fffed563cfe1a90a7b150fd)
1 /*
2  *
3  * Intel Management Engine Interface (Intel MEI) Linux driver
4  * Copyright (c) 2003-2012, Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  */
16 
17 #include <linux/sched.h>
18 #include <linux/wait.h>
19 #include <linux/delay.h>
20 #include <linux/slab.h>
21 #include <linux/pm_runtime.h>
22 
23 #include <linux/mei.h>
24 
25 #include "mei_dev.h"
26 #include "hbm.h"
27 #include "client.h"
28 
29 /**
30  * mei_me_cl_init - initialize me client
31  *
32  * @me_cl: me client
33  */
34 void mei_me_cl_init(struct mei_me_client *me_cl)
35 {
36 	INIT_LIST_HEAD(&me_cl->list);
37 	kref_init(&me_cl->refcnt);
38 }
39 
40 /**
41  * mei_me_cl_get - increases me client refcount
42  *
43  * @me_cl: me client
44  *
45  * Locking: called under "dev->device_lock" lock
46  *
47  * Return: me client or NULL
48  */
49 struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)
50 {
51 	if (me_cl && kref_get_unless_zero(&me_cl->refcnt))
52 		return me_cl;
53 
54 	return NULL;
55 }
56 
57 /**
58  * mei_me_cl_release - free me client
59  *
60  * Locking: called under "dev->device_lock" lock
61  *
62  * @ref: me_client refcount
63  */
64 static void mei_me_cl_release(struct kref *ref)
65 {
66 	struct mei_me_client *me_cl =
67 		container_of(ref, struct mei_me_client, refcnt);
68 
69 	kfree(me_cl);
70 }
71 
72 /**
73  * mei_me_cl_put - decrease me client refcount and free client if necessary
74  *
75  * Locking: called under "dev->device_lock" lock
76  *
77  * @me_cl: me client
78  */
79 void mei_me_cl_put(struct mei_me_client *me_cl)
80 {
81 	if (me_cl)
82 		kref_put(&me_cl->refcnt, mei_me_cl_release);
83 }
84 
85 /**
86  * __mei_me_cl_del  - delete me client from the list and decrease
87  *     reference counter
88  *
89  * @dev: mei device
90  * @me_cl: me client
91  *
92  * Locking: dev->me_clients_rwsem
93  */
94 static void __mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
95 {
96 	if (!me_cl)
97 		return;
98 
99 	list_del_init(&me_cl->list);
100 	mei_me_cl_put(me_cl);
101 }
102 
103 /**
104  * mei_me_cl_del - delete me client from the list and decrease
105  *     reference counter
106  *
107  * @dev: mei device
108  * @me_cl: me client
109  */
110 void mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
111 {
112 	down_write(&dev->me_clients_rwsem);
113 	__mei_me_cl_del(dev, me_cl);
114 	up_write(&dev->me_clients_rwsem);
115 }
116 
117 /**
118  * mei_me_cl_add - add me client to the list
119  *
120  * @dev: mei device
121  * @me_cl: me client
122  */
123 void mei_me_cl_add(struct mei_device *dev, struct mei_me_client *me_cl)
124 {
125 	down_write(&dev->me_clients_rwsem);
126 	list_add(&me_cl->list, &dev->me_clients);
127 	up_write(&dev->me_clients_rwsem);
128 }
129 
130 /**
131  * __mei_me_cl_by_uuid - locate me client by uuid
132  *	increases ref count
133  *
134  * @dev: mei device
135  * @uuid: me client uuid
136  *
137  * Return: me client or NULL if not found
138  *
139  * Locking: dev->me_clients_rwsem
140  */
141 static struct mei_me_client *__mei_me_cl_by_uuid(struct mei_device *dev,
142 					const uuid_le *uuid)
143 {
144 	struct mei_me_client *me_cl;
145 	const uuid_le *pn;
146 
147 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
148 
149 	list_for_each_entry(me_cl, &dev->me_clients, list) {
150 		pn = &me_cl->props.protocol_name;
151 		if (uuid_le_cmp(*uuid, *pn) == 0)
152 			return mei_me_cl_get(me_cl);
153 	}
154 
155 	return NULL;
156 }
157 
158 /**
159  * mei_me_cl_by_uuid - locate me client by uuid
160  *	increases ref count
161  *
162  * @dev: mei device
163  * @uuid: me client uuid
164  *
165  * Return: me client or NULL if not found
166  *
167  * Locking: dev->me_clients_rwsem
168  */
169 struct mei_me_client *mei_me_cl_by_uuid(struct mei_device *dev,
170 					const uuid_le *uuid)
171 {
172 	struct mei_me_client *me_cl;
173 
174 	down_read(&dev->me_clients_rwsem);
175 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
176 	up_read(&dev->me_clients_rwsem);
177 
178 	return me_cl;
179 }
180 
181 /**
182  * mei_me_cl_by_id - locate me client by client id
183  *	increases ref count
184  *
185  * @dev: the device structure
186  * @client_id: me client id
187  *
188  * Return: me client or NULL if not found
189  *
190  * Locking: dev->me_clients_rwsem
191  */
192 struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
193 {
194 
195 	struct mei_me_client *__me_cl, *me_cl = NULL;
196 
197 	down_read(&dev->me_clients_rwsem);
198 	list_for_each_entry(__me_cl, &dev->me_clients, list) {
199 		if (__me_cl->client_id == client_id) {
200 			me_cl = mei_me_cl_get(__me_cl);
201 			break;
202 		}
203 	}
204 	up_read(&dev->me_clients_rwsem);
205 
206 	return me_cl;
207 }
208 
209 /**
210  * __mei_me_cl_by_uuid_id - locate me client by client id and uuid
211  *	increases ref count
212  *
213  * @dev: the device structure
214  * @uuid: me client uuid
215  * @client_id: me client id
216  *
217  * Return: me client or null if not found
218  *
219  * Locking: dev->me_clients_rwsem
220  */
221 static struct mei_me_client *__mei_me_cl_by_uuid_id(struct mei_device *dev,
222 					   const uuid_le *uuid, u8 client_id)
223 {
224 	struct mei_me_client *me_cl;
225 	const uuid_le *pn;
226 
227 	WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
228 
229 	list_for_each_entry(me_cl, &dev->me_clients, list) {
230 		pn = &me_cl->props.protocol_name;
231 		if (uuid_le_cmp(*uuid, *pn) == 0 &&
232 		    me_cl->client_id == client_id)
233 			return mei_me_cl_get(me_cl);
234 	}
235 
236 	return NULL;
237 }
238 
239 
240 /**
241  * mei_me_cl_by_uuid_id - locate me client by client id and uuid
242  *	increases ref count
243  *
244  * @dev: the device structure
245  * @uuid: me client uuid
246  * @client_id: me client id
247  *
248  * Return: me client or null if not found
249  */
250 struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,
251 					   const uuid_le *uuid, u8 client_id)
252 {
253 	struct mei_me_client *me_cl;
254 
255 	down_read(&dev->me_clients_rwsem);
256 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, client_id);
257 	up_read(&dev->me_clients_rwsem);
258 
259 	return me_cl;
260 }
261 
262 /**
263  * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
264  *
265  * @dev: the device structure
266  * @uuid: me client uuid
267  *
268  * Locking: called under "dev->device_lock" lock
269  */
270 void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
271 {
272 	struct mei_me_client *me_cl;
273 
274 	dev_dbg(dev->dev, "remove %pUl\n", uuid);
275 
276 	down_write(&dev->me_clients_rwsem);
277 	me_cl = __mei_me_cl_by_uuid(dev, uuid);
278 	__mei_me_cl_del(dev, me_cl);
279 	up_write(&dev->me_clients_rwsem);
280 }
281 
282 /**
283  * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
284  *
285  * @dev: the device structure
286  * @uuid: me client uuid
287  * @id: me client id
288  *
289  * Locking: called under "dev->device_lock" lock
290  */
291 void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
292 {
293 	struct mei_me_client *me_cl;
294 
295 	dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
296 
297 	down_write(&dev->me_clients_rwsem);
298 	me_cl = __mei_me_cl_by_uuid_id(dev, uuid, id);
299 	__mei_me_cl_del(dev, me_cl);
300 	up_write(&dev->me_clients_rwsem);
301 }
302 
303 /**
304  * mei_me_cl_rm_all - remove all me clients
305  *
306  * @dev: the device structure
307  *
308  * Locking: called under "dev->device_lock" lock
309  */
310 void mei_me_cl_rm_all(struct mei_device *dev)
311 {
312 	struct mei_me_client *me_cl, *next;
313 
314 	down_write(&dev->me_clients_rwsem);
315 	list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
316 		__mei_me_cl_del(dev, me_cl);
317 	up_write(&dev->me_clients_rwsem);
318 }
319 
320 /**
321  * mei_cl_cmp_id - tells if the clients are the same
322  *
323  * @cl1: host client 1
324  * @cl2: host client 2
325  *
326  * Return: true  - if the clients has same host and me ids
327  *         false - otherwise
328  */
329 static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
330 				const struct mei_cl *cl2)
331 {
332 	return cl1 && cl2 &&
333 		(cl1->host_client_id == cl2->host_client_id) &&
334 		(mei_cl_me_id(cl1) == mei_cl_me_id(cl2));
335 }
336 
337 /**
338  * mei_io_cb_free - free mei_cb_private related memory
339  *
340  * @cb: mei callback struct
341  */
342 void mei_io_cb_free(struct mei_cl_cb *cb)
343 {
344 	if (cb == NULL)
345 		return;
346 
347 	list_del(&cb->list);
348 	kfree(cb->buf.data);
349 	kfree(cb);
350 }
351 
352 /**
353  * mei_io_cb_init - allocate and initialize io callback
354  *
355  * @cl: mei client
356  * @type: operation type
357  * @fp: pointer to file structure
358  *
359  * Return: mei_cl_cb pointer or NULL;
360  */
361 static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
362 					enum mei_cb_file_ops type,
363 					const struct file *fp)
364 {
365 	struct mei_cl_cb *cb;
366 
367 	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
368 	if (!cb)
369 		return NULL;
370 
371 	INIT_LIST_HEAD(&cb->list);
372 	cb->fp = fp;
373 	cb->cl = cl;
374 	cb->buf_idx = 0;
375 	cb->fop_type = type;
376 	return cb;
377 }
378 
379 /**
380  * __mei_io_list_flush - removes and frees cbs belonging to cl.
381  *
382  * @list:  an instance of our list structure
383  * @cl:    host client, can be NULL for flushing the whole list
384  * @free:  whether to free the cbs
385  */
386 static void __mei_io_list_flush(struct mei_cl_cb *list,
387 				struct mei_cl *cl, bool free)
388 {
389 	struct mei_cl_cb *cb, *next;
390 
391 	/* enable removing everything if no cl is specified */
392 	list_for_each_entry_safe(cb, next, &list->list, list) {
393 		if (!cl || mei_cl_cmp_id(cl, cb->cl)) {
394 			list_del_init(&cb->list);
395 			if (free)
396 				mei_io_cb_free(cb);
397 		}
398 	}
399 }
400 
401 /**
402  * mei_io_list_flush - removes list entry belonging to cl.
403  *
404  * @list:  An instance of our list structure
405  * @cl: host client
406  */
407 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
408 {
409 	__mei_io_list_flush(list, cl, false);
410 }
411 
412 /**
413  * mei_io_list_free - removes cb belonging to cl and free them
414  *
415  * @list:  An instance of our list structure
416  * @cl: host client
417  */
418 static inline void mei_io_list_free(struct mei_cl_cb *list, struct mei_cl *cl)
419 {
420 	__mei_io_list_flush(list, cl, true);
421 }
422 
423 /**
424  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
425  *
426  * @cl: host client
427  * @length: size of the buffer
428  * @type: operation type
429  * @fp: associated file pointer (might be NULL)
430  *
431  * Return: cb on success and NULL on failure
432  */
433 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
434 				  enum mei_cb_file_ops fop_type,
435 				  const struct file *fp)
436 {
437 	struct mei_cl_cb *cb;
438 
439 	cb = mei_io_cb_init(cl, fop_type, fp);
440 	if (!cb)
441 		return NULL;
442 
443 	if (length == 0)
444 		return cb;
445 
446 	cb->buf.data = kmalloc(length, GFP_KERNEL);
447 	if (!cb->buf.data) {
448 		mei_io_cb_free(cb);
449 		return NULL;
450 	}
451 	cb->buf.size = length;
452 
453 	return cb;
454 }
455 
456 /**
457  * mei_cl_enqueue_ctrl_wr_cb - a convenient wrapper for allocating
458  *     and enqueuing of the control commands cb
459  *
460  * @cl: host client
461  * @length: size of the buffer
462  * @type: operation type
463  * @fp: associated file pointer (might be NULL)
464  *
465  * Return: cb on success and NULL on failure
466  * Locking: called under "dev->device_lock" lock
467  */
468 struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
469 					    enum mei_cb_file_ops fop_type,
470 					    const struct file *fp)
471 {
472 	struct mei_cl_cb *cb;
473 
474 	/* for RX always allocate at least client's mtu */
475 	if (length)
476 		length = max_t(size_t, length, mei_cl_mtu(cl));
477 
478 	cb = mei_cl_alloc_cb(cl, length, fop_type, fp);
479 	if (!cb)
480 		return NULL;
481 
482 	list_add_tail(&cb->list, &cl->dev->ctrl_wr_list.list);
483 	return cb;
484 }
485 
486 /**
487  * mei_cl_read_cb - find this cl's callback in the read list
488  *     for a specific file
489  *
490  * @cl: host client
491  * @fp: file pointer (matching cb file object), may be NULL
492  *
493  * Return: cb on success, NULL if cb is not found
494  */
495 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
496 {
497 	struct mei_cl_cb *cb;
498 
499 	list_for_each_entry(cb, &cl->rd_completed, list)
500 		if (!fp || fp == cb->fp)
501 			return cb;
502 
503 	return NULL;
504 }
505 
506 /**
507  * mei_cl_read_cb_flush - free client's read pending and completed cbs
508  *   for a specific file
509  *
510  * @cl: host client
511  * @fp: file pointer (matching cb file object), may be NULL
512  */
513 void mei_cl_read_cb_flush(const struct mei_cl *cl, const struct file *fp)
514 {
515 	struct mei_cl_cb *cb, *next;
516 
517 	list_for_each_entry_safe(cb, next, &cl->rd_completed, list)
518 		if (!fp || fp == cb->fp)
519 			mei_io_cb_free(cb);
520 
521 
522 	list_for_each_entry_safe(cb, next, &cl->rd_pending, list)
523 		if (!fp || fp == cb->fp)
524 			mei_io_cb_free(cb);
525 }
526 
527 /**
528  * mei_cl_flush_queues - flushes queue lists belonging to cl.
529  *
530  * @cl: host client
531  * @fp: file pointer (matching cb file object), may be NULL
532  *
533  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
534  */
535 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
536 {
537 	struct mei_device *dev;
538 
539 	if (WARN_ON(!cl || !cl->dev))
540 		return -EINVAL;
541 
542 	dev = cl->dev;
543 
544 	cl_dbg(dev, cl, "remove list entry belonging to cl\n");
545 	mei_io_list_free(&cl->dev->write_list, cl);
546 	mei_io_list_free(&cl->dev->write_waiting_list, cl);
547 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
548 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
549 	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
550 
551 	mei_cl_read_cb_flush(cl, fp);
552 
553 	return 0;
554 }
555 
556 
557 /**
558  * mei_cl_init - initializes cl.
559  *
560  * @cl: host client to be initialized
561  * @dev: mei device
562  */
563 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
564 {
565 	memset(cl, 0, sizeof(struct mei_cl));
566 	init_waitqueue_head(&cl->wait);
567 	init_waitqueue_head(&cl->rx_wait);
568 	init_waitqueue_head(&cl->tx_wait);
569 	init_waitqueue_head(&cl->ev_wait);
570 	INIT_LIST_HEAD(&cl->rd_completed);
571 	INIT_LIST_HEAD(&cl->rd_pending);
572 	INIT_LIST_HEAD(&cl->link);
573 	cl->writing_state = MEI_IDLE;
574 	cl->state = MEI_FILE_INITIALIZING;
575 	cl->dev = dev;
576 }
577 
578 /**
579  * mei_cl_allocate - allocates cl  structure and sets it up.
580  *
581  * @dev: mei device
582  * Return:  The allocated file or NULL on failure
583  */
584 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
585 {
586 	struct mei_cl *cl;
587 
588 	cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
589 	if (!cl)
590 		return NULL;
591 
592 	mei_cl_init(cl, dev);
593 
594 	return cl;
595 }
596 
597 /**
598  * mei_cl_link - allocate host id in the host map
599  *
600  * @cl: host client
601  *
602  * Return: 0 on success
603  *	-EINVAL on incorrect values
604  *	-EMFILE if open count exceeded.
605  */
606 int mei_cl_link(struct mei_cl *cl)
607 {
608 	struct mei_device *dev;
609 	long open_handle_count;
610 	int id;
611 
612 	if (WARN_ON(!cl || !cl->dev))
613 		return -EINVAL;
614 
615 	dev = cl->dev;
616 
617 	id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
618 	if (id >= MEI_CLIENTS_MAX) {
619 		dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
620 		return -EMFILE;
621 	}
622 
623 	open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
624 	if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
625 		dev_err(dev->dev, "open_handle_count exceeded %d",
626 			MEI_MAX_OPEN_HANDLE_COUNT);
627 		return -EMFILE;
628 	}
629 
630 	dev->open_handle_count++;
631 
632 	cl->host_client_id = id;
633 	list_add_tail(&cl->link, &dev->file_list);
634 
635 	set_bit(id, dev->host_clients_map);
636 
637 	cl->state = MEI_FILE_INITIALIZING;
638 
639 	cl_dbg(dev, cl, "link cl\n");
640 	return 0;
641 }
642 
643 /**
644  * mei_cl_unlink - remove host client from the list
645  *
646  * @cl: host client
647  *
648  * Return: always 0
649  */
650 int mei_cl_unlink(struct mei_cl *cl)
651 {
652 	struct mei_device *dev;
653 
654 	/* don't shout on error exit path */
655 	if (!cl)
656 		return 0;
657 
658 	/* amthif might not be initialized */
659 	if (!cl->dev)
660 		return 0;
661 
662 	dev = cl->dev;
663 
664 	cl_dbg(dev, cl, "unlink client");
665 
666 	if (dev->open_handle_count > 0)
667 		dev->open_handle_count--;
668 
669 	/* never clear the 0 bit */
670 	if (cl->host_client_id)
671 		clear_bit(cl->host_client_id, dev->host_clients_map);
672 
673 	list_del_init(&cl->link);
674 
675 	cl->state = MEI_FILE_INITIALIZING;
676 
677 	return 0;
678 }
679 
680 void mei_host_client_init(struct mei_device *dev)
681 {
682 	dev->dev_state = MEI_DEV_ENABLED;
683 	dev->reset_count = 0;
684 
685 	schedule_work(&dev->bus_rescan_work);
686 
687 	pm_runtime_mark_last_busy(dev->dev);
688 	dev_dbg(dev->dev, "rpm: autosuspend\n");
689 	pm_runtime_autosuspend(dev->dev);
690 }
691 
692 /**
693  * mei_hbuf_acquire - try to acquire host buffer
694  *
695  * @dev: the device structure
696  * Return: true if host buffer was acquired
697  */
698 bool mei_hbuf_acquire(struct mei_device *dev)
699 {
700 	if (mei_pg_state(dev) == MEI_PG_ON ||
701 	    mei_pg_in_transition(dev)) {
702 		dev_dbg(dev->dev, "device is in pg\n");
703 		return false;
704 	}
705 
706 	if (!dev->hbuf_is_ready) {
707 		dev_dbg(dev->dev, "hbuf is not ready\n");
708 		return false;
709 	}
710 
711 	dev->hbuf_is_ready = false;
712 
713 	return true;
714 }
715 
716 /**
717  * mei_cl_wake_all - wake up readers, writers and event waiters so
718  *                 they can be interrupted
719  *
720  * @cl: host client
721  */
722 static void mei_cl_wake_all(struct mei_cl *cl)
723 {
724 	struct mei_device *dev = cl->dev;
725 
726 	/* synchronized under device mutex */
727 	if (waitqueue_active(&cl->rx_wait)) {
728 		cl_dbg(dev, cl, "Waking up reading client!\n");
729 		wake_up_interruptible(&cl->rx_wait);
730 	}
731 	/* synchronized under device mutex */
732 	if (waitqueue_active(&cl->tx_wait)) {
733 		cl_dbg(dev, cl, "Waking up writing client!\n");
734 		wake_up_interruptible(&cl->tx_wait);
735 	}
736 	/* synchronized under device mutex */
737 	if (waitqueue_active(&cl->ev_wait)) {
738 		cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
739 		wake_up_interruptible(&cl->ev_wait);
740 	}
741 	/* synchronized under device mutex */
742 	if (waitqueue_active(&cl->wait)) {
743 		cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
744 		wake_up(&cl->wait);
745 	}
746 }
747 
748 /**
749  * mei_cl_set_disconnected - set disconnected state and clear
750  *   associated states and resources
751  *
752  * @cl: host client
753  */
754 void mei_cl_set_disconnected(struct mei_cl *cl)
755 {
756 	struct mei_device *dev = cl->dev;
757 
758 	if (cl->state == MEI_FILE_DISCONNECTED ||
759 	    cl->state == MEI_FILE_INITIALIZING)
760 		return;
761 
762 	cl->state = MEI_FILE_DISCONNECTED;
763 	mei_io_list_free(&dev->write_list, cl);
764 	mei_io_list_free(&dev->write_waiting_list, cl);
765 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
766 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
767 	mei_cl_wake_all(cl);
768 	cl->rx_flow_ctrl_creds = 0;
769 	cl->tx_flow_ctrl_creds = 0;
770 	cl->timer_count = 0;
771 
772 	if (!cl->me_cl)
773 		return;
774 
775 	if (!WARN_ON(cl->me_cl->connect_count == 0))
776 		cl->me_cl->connect_count--;
777 
778 	if (cl->me_cl->connect_count == 0)
779 		cl->me_cl->tx_flow_ctrl_creds = 0;
780 
781 	mei_me_cl_put(cl->me_cl);
782 	cl->me_cl = NULL;
783 }
784 
785 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
786 {
787 	if (!mei_me_cl_get(me_cl))
788 		return -ENOENT;
789 
790 	/* only one connection is allowed for fixed address clients */
791 	if (me_cl->props.fixed_address) {
792 		if (me_cl->connect_count) {
793 			mei_me_cl_put(me_cl);
794 			return -EBUSY;
795 		}
796 	}
797 
798 	cl->me_cl = me_cl;
799 	cl->state = MEI_FILE_CONNECTING;
800 	cl->me_cl->connect_count++;
801 
802 	return 0;
803 }
804 
805 /*
806  * mei_cl_send_disconnect - send disconnect request
807  *
808  * @cl: host client
809  * @cb: callback block
810  *
811  * Return: 0, OK; otherwise, error.
812  */
813 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
814 {
815 	struct mei_device *dev;
816 	int ret;
817 
818 	dev = cl->dev;
819 
820 	ret = mei_hbm_cl_disconnect_req(dev, cl);
821 	cl->status = ret;
822 	if (ret) {
823 		cl->state = MEI_FILE_DISCONNECT_REPLY;
824 		return ret;
825 	}
826 
827 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
828 	cl->timer_count = MEI_CONNECT_TIMEOUT;
829 
830 	return 0;
831 }
832 
833 /**
834  * mei_cl_irq_disconnect - processes close related operation from
835  *	interrupt thread context - send disconnect request
836  *
837  * @cl: client
838  * @cb: callback block.
839  * @cmpl_list: complete list.
840  *
841  * Return: 0, OK; otherwise, error.
842  */
843 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
844 			    struct mei_cl_cb *cmpl_list)
845 {
846 	struct mei_device *dev = cl->dev;
847 	u32 msg_slots;
848 	int slots;
849 	int ret;
850 
851 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
852 	slots = mei_hbuf_empty_slots(dev);
853 
854 	if (slots < msg_slots)
855 		return -EMSGSIZE;
856 
857 	ret = mei_cl_send_disconnect(cl, cb);
858 	if (ret)
859 		list_move_tail(&cb->list, &cmpl_list->list);
860 
861 	return ret;
862 }
863 
864 /**
865  * __mei_cl_disconnect - disconnect host client from the me one
866  *     internal function runtime pm has to be already acquired
867  *
868  * @cl: host client
869  *
870  * Return: 0 on success, <0 on failure.
871  */
872 static int __mei_cl_disconnect(struct mei_cl *cl)
873 {
874 	struct mei_device *dev;
875 	struct mei_cl_cb *cb;
876 	int rets;
877 
878 	dev = cl->dev;
879 
880 	cl->state = MEI_FILE_DISCONNECTING;
881 
882 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
883 	if (!cb) {
884 		rets = -ENOMEM;
885 		goto out;
886 	}
887 
888 	if (mei_hbuf_acquire(dev)) {
889 		rets = mei_cl_send_disconnect(cl, cb);
890 		if (rets) {
891 			cl_err(dev, cl, "failed to disconnect.\n");
892 			goto out;
893 		}
894 	}
895 
896 	mutex_unlock(&dev->device_lock);
897 	wait_event_timeout(cl->wait,
898 			   cl->state == MEI_FILE_DISCONNECT_REPLY ||
899 			   cl->state == MEI_FILE_DISCONNECTED,
900 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
901 	mutex_lock(&dev->device_lock);
902 
903 	rets = cl->status;
904 	if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
905 	    cl->state != MEI_FILE_DISCONNECTED) {
906 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
907 		rets = -ETIME;
908 	}
909 
910 out:
911 	/* we disconnect also on error */
912 	mei_cl_set_disconnected(cl);
913 	if (!rets)
914 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
915 
916 	mei_io_cb_free(cb);
917 	return rets;
918 }
919 
920 /**
921  * mei_cl_disconnect - disconnect host client from the me one
922  *
923  * @cl: host client
924  *
925  * Locking: called under "dev->device_lock" lock
926  *
927  * Return: 0 on success, <0 on failure.
928  */
929 int mei_cl_disconnect(struct mei_cl *cl)
930 {
931 	struct mei_device *dev;
932 	int rets;
933 
934 	if (WARN_ON(!cl || !cl->dev))
935 		return -ENODEV;
936 
937 	dev = cl->dev;
938 
939 	cl_dbg(dev, cl, "disconnecting");
940 
941 	if (!mei_cl_is_connected(cl))
942 		return 0;
943 
944 	if (mei_cl_is_fixed_address(cl)) {
945 		mei_cl_set_disconnected(cl);
946 		return 0;
947 	}
948 
949 	rets = pm_runtime_get(dev->dev);
950 	if (rets < 0 && rets != -EINPROGRESS) {
951 		pm_runtime_put_noidle(dev->dev);
952 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
953 		return rets;
954 	}
955 
956 	rets = __mei_cl_disconnect(cl);
957 
958 	cl_dbg(dev, cl, "rpm: autosuspend\n");
959 	pm_runtime_mark_last_busy(dev->dev);
960 	pm_runtime_put_autosuspend(dev->dev);
961 
962 	return rets;
963 }
964 
965 
966 /**
967  * mei_cl_is_other_connecting - checks if other
968  *    client with the same me client id is connecting
969  *
970  * @cl: private data of the file object
971  *
972  * Return: true if other client is connected, false - otherwise.
973  */
974 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
975 {
976 	struct mei_device *dev;
977 	struct mei_cl_cb *cb;
978 
979 	dev = cl->dev;
980 
981 	list_for_each_entry(cb, &dev->ctrl_rd_list.list, list) {
982 		if (cb->fop_type == MEI_FOP_CONNECT &&
983 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
984 			return true;
985 	}
986 
987 	return false;
988 }
989 
990 /**
991  * mei_cl_send_connect - send connect request
992  *
993  * @cl: host client
994  * @cb: callback block
995  *
996  * Return: 0, OK; otherwise, error.
997  */
998 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
999 {
1000 	struct mei_device *dev;
1001 	int ret;
1002 
1003 	dev = cl->dev;
1004 
1005 	ret = mei_hbm_cl_connect_req(dev, cl);
1006 	cl->status = ret;
1007 	if (ret) {
1008 		cl->state = MEI_FILE_DISCONNECT_REPLY;
1009 		return ret;
1010 	}
1011 
1012 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1013 	cl->timer_count = MEI_CONNECT_TIMEOUT;
1014 	return 0;
1015 }
1016 
1017 /**
1018  * mei_cl_irq_connect - send connect request in irq_thread context
1019  *
1020  * @cl: host client
1021  * @cb: callback block
1022  * @cmpl_list: complete list
1023  *
1024  * Return: 0, OK; otherwise, error.
1025  */
1026 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1027 			      struct mei_cl_cb *cmpl_list)
1028 {
1029 	struct mei_device *dev = cl->dev;
1030 	u32 msg_slots;
1031 	int slots;
1032 	int rets;
1033 
1034 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1035 	slots = mei_hbuf_empty_slots(dev);
1036 
1037 	if (mei_cl_is_other_connecting(cl))
1038 		return 0;
1039 
1040 	if (slots < msg_slots)
1041 		return -EMSGSIZE;
1042 
1043 	rets = mei_cl_send_connect(cl, cb);
1044 	if (rets)
1045 		list_move_tail(&cb->list, &cmpl_list->list);
1046 
1047 	return rets;
1048 }
1049 
1050 /**
1051  * mei_cl_connect - connect host client to the me one
1052  *
1053  * @cl: host client
1054  * @me_cl: me client
1055  * @fp: pointer to file structure
1056  *
1057  * Locking: called under "dev->device_lock" lock
1058  *
1059  * Return: 0 on success, <0 on failure.
1060  */
1061 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1062 		   const struct file *fp)
1063 {
1064 	struct mei_device *dev;
1065 	struct mei_cl_cb *cb;
1066 	int rets;
1067 
1068 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1069 		return -ENODEV;
1070 
1071 	dev = cl->dev;
1072 
1073 	rets = mei_cl_set_connecting(cl, me_cl);
1074 	if (rets)
1075 		return rets;
1076 
1077 	if (mei_cl_is_fixed_address(cl)) {
1078 		cl->state = MEI_FILE_CONNECTED;
1079 		return 0;
1080 	}
1081 
1082 	rets = pm_runtime_get(dev->dev);
1083 	if (rets < 0 && rets != -EINPROGRESS) {
1084 		pm_runtime_put_noidle(dev->dev);
1085 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1086 		goto nortpm;
1087 	}
1088 
1089 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1090 	if (!cb) {
1091 		rets = -ENOMEM;
1092 		goto out;
1093 	}
1094 
1095 	/* run hbuf acquire last so we don't have to undo */
1096 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1097 		rets = mei_cl_send_connect(cl, cb);
1098 		if (rets)
1099 			goto out;
1100 	}
1101 
1102 	mutex_unlock(&dev->device_lock);
1103 	wait_event_timeout(cl->wait,
1104 			(cl->state == MEI_FILE_CONNECTED ||
1105 			 cl->state == MEI_FILE_DISCONNECTED ||
1106 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1107 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1108 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1109 	mutex_lock(&dev->device_lock);
1110 
1111 	if (!mei_cl_is_connected(cl)) {
1112 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1113 			mei_io_list_flush(&dev->ctrl_rd_list, cl);
1114 			mei_io_list_flush(&dev->ctrl_wr_list, cl);
1115 			 /* ignore disconnect return valuue;
1116 			  * in case of failure reset will be invoked
1117 			  */
1118 			__mei_cl_disconnect(cl);
1119 			rets = -EFAULT;
1120 			goto out;
1121 		}
1122 
1123 		/* timeout or something went really wrong */
1124 		if (!cl->status)
1125 			cl->status = -EFAULT;
1126 	}
1127 
1128 	rets = cl->status;
1129 out:
1130 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1131 	pm_runtime_mark_last_busy(dev->dev);
1132 	pm_runtime_put_autosuspend(dev->dev);
1133 
1134 	mei_io_cb_free(cb);
1135 
1136 nortpm:
1137 	if (!mei_cl_is_connected(cl))
1138 		mei_cl_set_disconnected(cl);
1139 
1140 	return rets;
1141 }
1142 
1143 /**
1144  * mei_cl_alloc_linked - allocate and link host client
1145  *
1146  * @dev: the device structure
1147  *
1148  * Return: cl on success ERR_PTR on failure
1149  */
1150 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1151 {
1152 	struct mei_cl *cl;
1153 	int ret;
1154 
1155 	cl = mei_cl_allocate(dev);
1156 	if (!cl) {
1157 		ret = -ENOMEM;
1158 		goto err;
1159 	}
1160 
1161 	ret = mei_cl_link(cl);
1162 	if (ret)
1163 		goto err;
1164 
1165 	return cl;
1166 err:
1167 	kfree(cl);
1168 	return ERR_PTR(ret);
1169 }
1170 
1171 /**
1172  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1173  *
1174  * @cl: host client
1175  *
1176  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1177  */
1178 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1179 {
1180 	if (WARN_ON(!cl || !cl->me_cl))
1181 		return -EINVAL;
1182 
1183 	if (cl->tx_flow_ctrl_creds > 0)
1184 		return 1;
1185 
1186 	if (mei_cl_is_fixed_address(cl))
1187 		return 1;
1188 
1189 	if (mei_cl_is_single_recv_buf(cl)) {
1190 		if (cl->me_cl->tx_flow_ctrl_creds > 0)
1191 			return 1;
1192 	}
1193 	return 0;
1194 }
1195 
1196 /**
1197  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1198  *   for a client
1199  *
1200  * @cl: host client
1201  *
1202  * Return:
1203  *	0 on success
1204  *	-EINVAL when ctrl credits are <= 0
1205  */
1206 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1207 {
1208 	if (WARN_ON(!cl || !cl->me_cl))
1209 		return -EINVAL;
1210 
1211 	if (mei_cl_is_fixed_address(cl))
1212 		return 0;
1213 
1214 	if (mei_cl_is_single_recv_buf(cl)) {
1215 		if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1216 			return -EINVAL;
1217 		cl->me_cl->tx_flow_ctrl_creds--;
1218 	} else {
1219 		if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1220 			return -EINVAL;
1221 		cl->tx_flow_ctrl_creds--;
1222 	}
1223 	return 0;
1224 }
1225 
1226 /**
1227  *  mei_cl_notify_fop2req - convert fop to proper request
1228  *
1229  * @fop: client notification start response command
1230  *
1231  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1232  */
1233 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1234 {
1235 	if (fop == MEI_FOP_NOTIFY_START)
1236 		return MEI_HBM_NOTIFICATION_START;
1237 	else
1238 		return MEI_HBM_NOTIFICATION_STOP;
1239 }
1240 
1241 /**
1242  *  mei_cl_notify_req2fop - convert notification request top file operation type
1243  *
1244  * @req: hbm notification request type
1245  *
1246  * Return:  MEI_FOP_NOTIFY_START/STOP
1247  */
1248 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1249 {
1250 	if (req == MEI_HBM_NOTIFICATION_START)
1251 		return MEI_FOP_NOTIFY_START;
1252 	else
1253 		return MEI_FOP_NOTIFY_STOP;
1254 }
1255 
1256 /**
1257  * mei_cl_irq_notify - send notification request in irq_thread context
1258  *
1259  * @cl: client
1260  * @cb: callback block.
1261  * @cmpl_list: complete list.
1262  *
1263  * Return: 0 on such and error otherwise.
1264  */
1265 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1266 		      struct mei_cl_cb *cmpl_list)
1267 {
1268 	struct mei_device *dev = cl->dev;
1269 	u32 msg_slots;
1270 	int slots;
1271 	int ret;
1272 	bool request;
1273 
1274 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1275 	slots = mei_hbuf_empty_slots(dev);
1276 
1277 	if (slots < msg_slots)
1278 		return -EMSGSIZE;
1279 
1280 	request = mei_cl_notify_fop2req(cb->fop_type);
1281 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1282 	if (ret) {
1283 		cl->status = ret;
1284 		list_move_tail(&cb->list, &cmpl_list->list);
1285 		return ret;
1286 	}
1287 
1288 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1289 	return 0;
1290 }
1291 
1292 /**
1293  * mei_cl_notify_request - send notification stop/start request
1294  *
1295  * @cl: host client
1296  * @fp: associate request with file
1297  * @request: 1 for start or 0 for stop
1298  *
1299  * Locking: called under "dev->device_lock" lock
1300  *
1301  * Return: 0 on such and error otherwise.
1302  */
1303 int mei_cl_notify_request(struct mei_cl *cl,
1304 			  const struct file *fp, u8 request)
1305 {
1306 	struct mei_device *dev;
1307 	struct mei_cl_cb *cb;
1308 	enum mei_cb_file_ops fop_type;
1309 	int rets;
1310 
1311 	if (WARN_ON(!cl || !cl->dev))
1312 		return -ENODEV;
1313 
1314 	dev = cl->dev;
1315 
1316 	if (!dev->hbm_f_ev_supported) {
1317 		cl_dbg(dev, cl, "notifications not supported\n");
1318 		return -EOPNOTSUPP;
1319 	}
1320 
1321 	rets = pm_runtime_get(dev->dev);
1322 	if (rets < 0 && rets != -EINPROGRESS) {
1323 		pm_runtime_put_noidle(dev->dev);
1324 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1325 		return rets;
1326 	}
1327 
1328 	fop_type = mei_cl_notify_req2fop(request);
1329 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1330 	if (!cb) {
1331 		rets = -ENOMEM;
1332 		goto out;
1333 	}
1334 
1335 	if (mei_hbuf_acquire(dev)) {
1336 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1337 			rets = -ENODEV;
1338 			goto out;
1339 		}
1340 		list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1341 	}
1342 
1343 	mutex_unlock(&dev->device_lock);
1344 	wait_event_timeout(cl->wait,
1345 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1346 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1347 	mutex_lock(&dev->device_lock);
1348 
1349 	if (cl->notify_en != request && !cl->status)
1350 		cl->status = -EFAULT;
1351 
1352 	rets = cl->status;
1353 
1354 out:
1355 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1356 	pm_runtime_mark_last_busy(dev->dev);
1357 	pm_runtime_put_autosuspend(dev->dev);
1358 
1359 	mei_io_cb_free(cb);
1360 	return rets;
1361 }
1362 
1363 /**
1364  * mei_cl_notify - raise notification
1365  *
1366  * @cl: host client
1367  *
1368  * Locking: called under "dev->device_lock" lock
1369  */
1370 void mei_cl_notify(struct mei_cl *cl)
1371 {
1372 	struct mei_device *dev;
1373 
1374 	if (!cl || !cl->dev)
1375 		return;
1376 
1377 	dev = cl->dev;
1378 
1379 	if (!cl->notify_en)
1380 		return;
1381 
1382 	cl_dbg(dev, cl, "notify event");
1383 	cl->notify_ev = true;
1384 	if (!mei_cl_bus_notify_event(cl))
1385 		wake_up_interruptible(&cl->ev_wait);
1386 
1387 	if (cl->ev_async)
1388 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1389 
1390 }
1391 
1392 /**
1393  * mei_cl_notify_get - get or wait for notification event
1394  *
1395  * @cl: host client
1396  * @block: this request is blocking
1397  * @notify_ev: true if notification event was received
1398  *
1399  * Locking: called under "dev->device_lock" lock
1400  *
1401  * Return: 0 on such and error otherwise.
1402  */
1403 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1404 {
1405 	struct mei_device *dev;
1406 	int rets;
1407 
1408 	*notify_ev = false;
1409 
1410 	if (WARN_ON(!cl || !cl->dev))
1411 		return -ENODEV;
1412 
1413 	dev = cl->dev;
1414 
1415 	if (!mei_cl_is_connected(cl))
1416 		return -ENODEV;
1417 
1418 	if (cl->notify_ev)
1419 		goto out;
1420 
1421 	if (!block)
1422 		return -EAGAIN;
1423 
1424 	mutex_unlock(&dev->device_lock);
1425 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1426 	mutex_lock(&dev->device_lock);
1427 
1428 	if (rets < 0)
1429 		return rets;
1430 
1431 out:
1432 	*notify_ev = cl->notify_ev;
1433 	cl->notify_ev = false;
1434 	return 0;
1435 }
1436 
1437 /**
1438  * mei_cl_read_start - the start read client message function.
1439  *
1440  * @cl: host client
1441  * @length: number of bytes to read
1442  * @fp: pointer to file structure
1443  *
1444  * Return: 0 on success, <0 on failure.
1445  */
1446 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1447 {
1448 	struct mei_device *dev;
1449 	struct mei_cl_cb *cb;
1450 	int rets;
1451 
1452 	if (WARN_ON(!cl || !cl->dev))
1453 		return -ENODEV;
1454 
1455 	dev = cl->dev;
1456 
1457 	if (!mei_cl_is_connected(cl))
1458 		return -ENODEV;
1459 
1460 	if (!mei_me_cl_is_active(cl->me_cl)) {
1461 		cl_err(dev, cl, "no such me client\n");
1462 		return  -ENOTTY;
1463 	}
1464 
1465 	if (mei_cl_is_fixed_address(cl) || cl == &dev->iamthif_cl)
1466 		return 0;
1467 
1468 	/* HW currently supports only one pending read */
1469 	if (cl->rx_flow_ctrl_creds)
1470 		return -EBUSY;
1471 
1472 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1473 	if (!cb)
1474 		return -ENOMEM;
1475 
1476 	rets = pm_runtime_get(dev->dev);
1477 	if (rets < 0 && rets != -EINPROGRESS) {
1478 		pm_runtime_put_noidle(dev->dev);
1479 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1480 		goto nortpm;
1481 	}
1482 
1483 	rets = 0;
1484 	if (mei_hbuf_acquire(dev)) {
1485 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1486 		if (rets < 0)
1487 			goto out;
1488 
1489 		list_move_tail(&cb->list, &cl->rd_pending);
1490 	}
1491 	cl->rx_flow_ctrl_creds++;
1492 
1493 out:
1494 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1495 	pm_runtime_mark_last_busy(dev->dev);
1496 	pm_runtime_put_autosuspend(dev->dev);
1497 nortpm:
1498 	if (rets)
1499 		mei_io_cb_free(cb);
1500 
1501 	return rets;
1502 }
1503 
1504 /**
1505  * mei_cl_irq_write - write a message to device
1506  *	from the interrupt thread context
1507  *
1508  * @cl: client
1509  * @cb: callback block.
1510  * @cmpl_list: complete list.
1511  *
1512  * Return: 0, OK; otherwise error.
1513  */
1514 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1515 		     struct mei_cl_cb *cmpl_list)
1516 {
1517 	struct mei_device *dev;
1518 	struct mei_msg_data *buf;
1519 	struct mei_msg_hdr mei_hdr;
1520 	size_t len;
1521 	u32 msg_slots;
1522 	int slots;
1523 	int rets;
1524 	bool first_chunk;
1525 
1526 	if (WARN_ON(!cl || !cl->dev))
1527 		return -ENODEV;
1528 
1529 	dev = cl->dev;
1530 
1531 	buf = &cb->buf;
1532 
1533 	first_chunk = cb->buf_idx == 0;
1534 
1535 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1536 	if (rets < 0)
1537 		return rets;
1538 
1539 	if (rets == 0) {
1540 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1541 		return 0;
1542 	}
1543 
1544 	slots = mei_hbuf_empty_slots(dev);
1545 	len = buf->size - cb->buf_idx;
1546 	msg_slots = mei_data2slots(len);
1547 
1548 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1549 	mei_hdr.me_addr = mei_cl_me_id(cl);
1550 	mei_hdr.reserved = 0;
1551 	mei_hdr.internal = cb->internal;
1552 
1553 	if (slots >= msg_slots) {
1554 		mei_hdr.length = len;
1555 		mei_hdr.msg_complete = 1;
1556 	/* Split the message only if we can write the whole host buffer */
1557 	} else if (slots == dev->hbuf_depth) {
1558 		msg_slots = slots;
1559 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1560 		mei_hdr.length = len;
1561 		mei_hdr.msg_complete = 0;
1562 	} else {
1563 		/* wait for next time the host buffer is empty */
1564 		return 0;
1565 	}
1566 
1567 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1568 			cb->buf.size, cb->buf_idx);
1569 
1570 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1571 	if (rets) {
1572 		cl->status = rets;
1573 		list_move_tail(&cb->list, &cmpl_list->list);
1574 		return rets;
1575 	}
1576 
1577 	cl->status = 0;
1578 	cl->writing_state = MEI_WRITING;
1579 	cb->buf_idx += mei_hdr.length;
1580 	cb->completed = mei_hdr.msg_complete == 1;
1581 
1582 	if (first_chunk) {
1583 		if (mei_cl_tx_flow_ctrl_creds_reduce(cl))
1584 			return -EIO;
1585 	}
1586 
1587 	if (mei_hdr.msg_complete)
1588 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1589 
1590 	return 0;
1591 }
1592 
1593 /**
1594  * mei_cl_write - submit a write cb to mei device
1595  *	assumes device_lock is locked
1596  *
1597  * @cl: host client
1598  * @cb: write callback with filled data
1599  * @blocking: block until completed
1600  *
1601  * Return: number of bytes sent on success, <0 on failure.
1602  */
1603 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1604 {
1605 	struct mei_device *dev;
1606 	struct mei_msg_data *buf;
1607 	struct mei_msg_hdr mei_hdr;
1608 	int size;
1609 	int rets;
1610 
1611 
1612 	if (WARN_ON(!cl || !cl->dev))
1613 		return -ENODEV;
1614 
1615 	if (WARN_ON(!cb))
1616 		return -EINVAL;
1617 
1618 	dev = cl->dev;
1619 
1620 	buf = &cb->buf;
1621 	size = buf->size;
1622 
1623 	cl_dbg(dev, cl, "size=%d\n", size);
1624 
1625 	rets = pm_runtime_get(dev->dev);
1626 	if (rets < 0 && rets != -EINPROGRESS) {
1627 		pm_runtime_put_noidle(dev->dev);
1628 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1629 		goto free;
1630 	}
1631 
1632 	cb->buf_idx = 0;
1633 	cl->writing_state = MEI_IDLE;
1634 
1635 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1636 	mei_hdr.me_addr = mei_cl_me_id(cl);
1637 	mei_hdr.reserved = 0;
1638 	mei_hdr.msg_complete = 0;
1639 	mei_hdr.internal = cb->internal;
1640 
1641 	rets = mei_cl_tx_flow_ctrl_creds(cl);
1642 	if (rets < 0)
1643 		goto err;
1644 
1645 	if (rets == 0) {
1646 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1647 		rets = size;
1648 		goto out;
1649 	}
1650 	if (!mei_hbuf_acquire(dev)) {
1651 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1652 		rets = size;
1653 		goto out;
1654 	}
1655 
1656 	/* Check for a maximum length */
1657 	if (size > mei_hbuf_max_len(dev)) {
1658 		mei_hdr.length = mei_hbuf_max_len(dev);
1659 		mei_hdr.msg_complete = 0;
1660 	} else {
1661 		mei_hdr.length = size;
1662 		mei_hdr.msg_complete = 1;
1663 	}
1664 
1665 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1666 	if (rets)
1667 		goto err;
1668 
1669 	rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1670 	if (rets)
1671 		goto err;
1672 
1673 	cl->writing_state = MEI_WRITING;
1674 	cb->buf_idx = mei_hdr.length;
1675 	cb->completed = mei_hdr.msg_complete == 1;
1676 
1677 out:
1678 	if (mei_hdr.msg_complete)
1679 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1680 	else
1681 		list_add_tail(&cb->list, &dev->write_list.list);
1682 
1683 	cb = NULL;
1684 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1685 
1686 		mutex_unlock(&dev->device_lock);
1687 		rets = wait_event_interruptible(cl->tx_wait,
1688 				cl->writing_state == MEI_WRITE_COMPLETE ||
1689 				(!mei_cl_is_connected(cl)));
1690 		mutex_lock(&dev->device_lock);
1691 		/* wait_event_interruptible returns -ERESTARTSYS */
1692 		if (rets) {
1693 			if (signal_pending(current))
1694 				rets = -EINTR;
1695 			goto err;
1696 		}
1697 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1698 			rets = -EFAULT;
1699 			goto err;
1700 		}
1701 	}
1702 
1703 	rets = size;
1704 err:
1705 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1706 	pm_runtime_mark_last_busy(dev->dev);
1707 	pm_runtime_put_autosuspend(dev->dev);
1708 free:
1709 	mei_io_cb_free(cb);
1710 
1711 	return rets;
1712 }
1713 
1714 
1715 /**
1716  * mei_cl_complete - processes completed operation for a client
1717  *
1718  * @cl: private data of the file object.
1719  * @cb: callback block.
1720  */
1721 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1722 {
1723 	struct mei_device *dev = cl->dev;
1724 
1725 	switch (cb->fop_type) {
1726 	case MEI_FOP_WRITE:
1727 		mei_io_cb_free(cb);
1728 		cl->writing_state = MEI_WRITE_COMPLETE;
1729 		if (waitqueue_active(&cl->tx_wait)) {
1730 			wake_up_interruptible(&cl->tx_wait);
1731 		} else {
1732 			pm_runtime_mark_last_busy(dev->dev);
1733 			pm_request_autosuspend(dev->dev);
1734 		}
1735 		break;
1736 
1737 	case MEI_FOP_READ:
1738 		list_add_tail(&cb->list, &cl->rd_completed);
1739 		if (!mei_cl_is_fixed_address(cl) &&
1740 		    !WARN_ON(!cl->rx_flow_ctrl_creds))
1741 			cl->rx_flow_ctrl_creds--;
1742 		if (!mei_cl_bus_rx_event(cl))
1743 			wake_up_interruptible(&cl->rx_wait);
1744 		break;
1745 
1746 	case MEI_FOP_CONNECT:
1747 	case MEI_FOP_DISCONNECT:
1748 	case MEI_FOP_NOTIFY_STOP:
1749 	case MEI_FOP_NOTIFY_START:
1750 		if (waitqueue_active(&cl->wait))
1751 			wake_up(&cl->wait);
1752 
1753 		break;
1754 	case MEI_FOP_DISCONNECT_RSP:
1755 		mei_io_cb_free(cb);
1756 		mei_cl_set_disconnected(cl);
1757 		break;
1758 	default:
1759 		BUG_ON(0);
1760 	}
1761 }
1762 
1763 
1764 /**
1765  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1766  *
1767  * @dev: mei device
1768  */
1769 void mei_cl_all_disconnect(struct mei_device *dev)
1770 {
1771 	struct mei_cl *cl;
1772 
1773 	list_for_each_entry(cl, &dev->file_list, link)
1774 		mei_cl_set_disconnected(cl);
1775 }
1776