xref: /openbmc/linux/drivers/misc/mei/client.c (revision e983940270f10fe8551baf0098be76ea478294a3)
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 	mei_schedule_stall_timer(dev);
830 
831 	return 0;
832 }
833 
834 /**
835  * mei_cl_irq_disconnect - processes close related operation from
836  *	interrupt thread context - send disconnect request
837  *
838  * @cl: client
839  * @cb: callback block.
840  * @cmpl_list: complete list.
841  *
842  * Return: 0, OK; otherwise, error.
843  */
844 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
845 			    struct mei_cl_cb *cmpl_list)
846 {
847 	struct mei_device *dev = cl->dev;
848 	u32 msg_slots;
849 	int slots;
850 	int ret;
851 
852 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
853 	slots = mei_hbuf_empty_slots(dev);
854 
855 	if (slots < msg_slots)
856 		return -EMSGSIZE;
857 
858 	ret = mei_cl_send_disconnect(cl, cb);
859 	if (ret)
860 		list_move_tail(&cb->list, &cmpl_list->list);
861 
862 	return ret;
863 }
864 
865 /**
866  * __mei_cl_disconnect - disconnect host client from the me one
867  *     internal function runtime pm has to be already acquired
868  *
869  * @cl: host client
870  *
871  * Return: 0 on success, <0 on failure.
872  */
873 static int __mei_cl_disconnect(struct mei_cl *cl)
874 {
875 	struct mei_device *dev;
876 	struct mei_cl_cb *cb;
877 	int rets;
878 
879 	dev = cl->dev;
880 
881 	cl->state = MEI_FILE_DISCONNECTING;
882 
883 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
884 	if (!cb) {
885 		rets = -ENOMEM;
886 		goto out;
887 	}
888 
889 	if (mei_hbuf_acquire(dev)) {
890 		rets = mei_cl_send_disconnect(cl, cb);
891 		if (rets) {
892 			cl_err(dev, cl, "failed to disconnect.\n");
893 			goto out;
894 		}
895 	}
896 
897 	mutex_unlock(&dev->device_lock);
898 	wait_event_timeout(cl->wait,
899 			   cl->state == MEI_FILE_DISCONNECT_REPLY ||
900 			   cl->state == MEI_FILE_DISCONNECTED,
901 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
902 	mutex_lock(&dev->device_lock);
903 
904 	rets = cl->status;
905 	if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
906 	    cl->state != MEI_FILE_DISCONNECTED) {
907 		cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
908 		rets = -ETIME;
909 	}
910 
911 out:
912 	/* we disconnect also on error */
913 	mei_cl_set_disconnected(cl);
914 	if (!rets)
915 		cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
916 
917 	mei_io_cb_free(cb);
918 	return rets;
919 }
920 
921 /**
922  * mei_cl_disconnect - disconnect host client from the me one
923  *
924  * @cl: host client
925  *
926  * Locking: called under "dev->device_lock" lock
927  *
928  * Return: 0 on success, <0 on failure.
929  */
930 int mei_cl_disconnect(struct mei_cl *cl)
931 {
932 	struct mei_device *dev;
933 	int rets;
934 
935 	if (WARN_ON(!cl || !cl->dev))
936 		return -ENODEV;
937 
938 	dev = cl->dev;
939 
940 	cl_dbg(dev, cl, "disconnecting");
941 
942 	if (!mei_cl_is_connected(cl))
943 		return 0;
944 
945 	if (mei_cl_is_fixed_address(cl)) {
946 		mei_cl_set_disconnected(cl);
947 		return 0;
948 	}
949 
950 	rets = pm_runtime_get(dev->dev);
951 	if (rets < 0 && rets != -EINPROGRESS) {
952 		pm_runtime_put_noidle(dev->dev);
953 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
954 		return rets;
955 	}
956 
957 	rets = __mei_cl_disconnect(cl);
958 
959 	cl_dbg(dev, cl, "rpm: autosuspend\n");
960 	pm_runtime_mark_last_busy(dev->dev);
961 	pm_runtime_put_autosuspend(dev->dev);
962 
963 	return rets;
964 }
965 
966 
967 /**
968  * mei_cl_is_other_connecting - checks if other
969  *    client with the same me client id is connecting
970  *
971  * @cl: private data of the file object
972  *
973  * Return: true if other client is connected, false - otherwise.
974  */
975 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
976 {
977 	struct mei_device *dev;
978 	struct mei_cl_cb *cb;
979 
980 	dev = cl->dev;
981 
982 	list_for_each_entry(cb, &dev->ctrl_rd_list.list, list) {
983 		if (cb->fop_type == MEI_FOP_CONNECT &&
984 		    mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
985 			return true;
986 	}
987 
988 	return false;
989 }
990 
991 /**
992  * mei_cl_send_connect - send connect request
993  *
994  * @cl: host client
995  * @cb: callback block
996  *
997  * Return: 0, OK; otherwise, error.
998  */
999 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
1000 {
1001 	struct mei_device *dev;
1002 	int ret;
1003 
1004 	dev = cl->dev;
1005 
1006 	ret = mei_hbm_cl_connect_req(dev, cl);
1007 	cl->status = ret;
1008 	if (ret) {
1009 		cl->state = MEI_FILE_DISCONNECT_REPLY;
1010 		return ret;
1011 	}
1012 
1013 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1014 	cl->timer_count = MEI_CONNECT_TIMEOUT;
1015 	mei_schedule_stall_timer(dev);
1016 	return 0;
1017 }
1018 
1019 /**
1020  * mei_cl_irq_connect - send connect request in irq_thread context
1021  *
1022  * @cl: host client
1023  * @cb: callback block
1024  * @cmpl_list: complete list
1025  *
1026  * Return: 0, OK; otherwise, error.
1027  */
1028 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1029 			      struct mei_cl_cb *cmpl_list)
1030 {
1031 	struct mei_device *dev = cl->dev;
1032 	u32 msg_slots;
1033 	int slots;
1034 	int rets;
1035 
1036 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1037 	slots = mei_hbuf_empty_slots(dev);
1038 
1039 	if (mei_cl_is_other_connecting(cl))
1040 		return 0;
1041 
1042 	if (slots < msg_slots)
1043 		return -EMSGSIZE;
1044 
1045 	rets = mei_cl_send_connect(cl, cb);
1046 	if (rets)
1047 		list_move_tail(&cb->list, &cmpl_list->list);
1048 
1049 	return rets;
1050 }
1051 
1052 /**
1053  * mei_cl_connect - connect host client to the me one
1054  *
1055  * @cl: host client
1056  * @me_cl: me client
1057  * @fp: pointer to file structure
1058  *
1059  * Locking: called under "dev->device_lock" lock
1060  *
1061  * Return: 0 on success, <0 on failure.
1062  */
1063 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1064 		   const struct file *fp)
1065 {
1066 	struct mei_device *dev;
1067 	struct mei_cl_cb *cb;
1068 	int rets;
1069 
1070 	if (WARN_ON(!cl || !cl->dev || !me_cl))
1071 		return -ENODEV;
1072 
1073 	dev = cl->dev;
1074 
1075 	rets = mei_cl_set_connecting(cl, me_cl);
1076 	if (rets)
1077 		return rets;
1078 
1079 	if (mei_cl_is_fixed_address(cl)) {
1080 		cl->state = MEI_FILE_CONNECTED;
1081 		return 0;
1082 	}
1083 
1084 	rets = pm_runtime_get(dev->dev);
1085 	if (rets < 0 && rets != -EINPROGRESS) {
1086 		pm_runtime_put_noidle(dev->dev);
1087 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1088 		goto nortpm;
1089 	}
1090 
1091 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1092 	if (!cb) {
1093 		rets = -ENOMEM;
1094 		goto out;
1095 	}
1096 
1097 	/* run hbuf acquire last so we don't have to undo */
1098 	if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1099 		rets = mei_cl_send_connect(cl, cb);
1100 		if (rets)
1101 			goto out;
1102 	}
1103 
1104 	mutex_unlock(&dev->device_lock);
1105 	wait_event_timeout(cl->wait,
1106 			(cl->state == MEI_FILE_CONNECTED ||
1107 			 cl->state == MEI_FILE_DISCONNECTED ||
1108 			 cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1109 			 cl->state == MEI_FILE_DISCONNECT_REPLY),
1110 			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1111 	mutex_lock(&dev->device_lock);
1112 
1113 	if (!mei_cl_is_connected(cl)) {
1114 		if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1115 			mei_io_list_flush(&dev->ctrl_rd_list, cl);
1116 			mei_io_list_flush(&dev->ctrl_wr_list, cl);
1117 			 /* ignore disconnect return valuue;
1118 			  * in case of failure reset will be invoked
1119 			  */
1120 			__mei_cl_disconnect(cl);
1121 			rets = -EFAULT;
1122 			goto out;
1123 		}
1124 
1125 		/* timeout or something went really wrong */
1126 		if (!cl->status)
1127 			cl->status = -EFAULT;
1128 	}
1129 
1130 	rets = cl->status;
1131 out:
1132 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1133 	pm_runtime_mark_last_busy(dev->dev);
1134 	pm_runtime_put_autosuspend(dev->dev);
1135 
1136 	mei_io_cb_free(cb);
1137 
1138 nortpm:
1139 	if (!mei_cl_is_connected(cl))
1140 		mei_cl_set_disconnected(cl);
1141 
1142 	return rets;
1143 }
1144 
1145 /**
1146  * mei_cl_alloc_linked - allocate and link host client
1147  *
1148  * @dev: the device structure
1149  *
1150  * Return: cl on success ERR_PTR on failure
1151  */
1152 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1153 {
1154 	struct mei_cl *cl;
1155 	int ret;
1156 
1157 	cl = mei_cl_allocate(dev);
1158 	if (!cl) {
1159 		ret = -ENOMEM;
1160 		goto err;
1161 	}
1162 
1163 	ret = mei_cl_link(cl);
1164 	if (ret)
1165 		goto err;
1166 
1167 	return cl;
1168 err:
1169 	kfree(cl);
1170 	return ERR_PTR(ret);
1171 }
1172 
1173 /**
1174  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1175  *
1176  * @cl: host client
1177  *
1178  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1179  */
1180 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1181 {
1182 	if (WARN_ON(!cl || !cl->me_cl))
1183 		return -EINVAL;
1184 
1185 	if (cl->tx_flow_ctrl_creds > 0)
1186 		return 1;
1187 
1188 	if (mei_cl_is_fixed_address(cl))
1189 		return 1;
1190 
1191 	if (mei_cl_is_single_recv_buf(cl)) {
1192 		if (cl->me_cl->tx_flow_ctrl_creds > 0)
1193 			return 1;
1194 	}
1195 	return 0;
1196 }
1197 
1198 /**
1199  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1200  *   for a client
1201  *
1202  * @cl: host client
1203  *
1204  * Return:
1205  *	0 on success
1206  *	-EINVAL when ctrl credits are <= 0
1207  */
1208 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1209 {
1210 	if (WARN_ON(!cl || !cl->me_cl))
1211 		return -EINVAL;
1212 
1213 	if (mei_cl_is_fixed_address(cl))
1214 		return 0;
1215 
1216 	if (mei_cl_is_single_recv_buf(cl)) {
1217 		if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1218 			return -EINVAL;
1219 		cl->me_cl->tx_flow_ctrl_creds--;
1220 	} else {
1221 		if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1222 			return -EINVAL;
1223 		cl->tx_flow_ctrl_creds--;
1224 	}
1225 	return 0;
1226 }
1227 
1228 /**
1229  *  mei_cl_notify_fop2req - convert fop to proper request
1230  *
1231  * @fop: client notification start response command
1232  *
1233  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1234  */
1235 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1236 {
1237 	if (fop == MEI_FOP_NOTIFY_START)
1238 		return MEI_HBM_NOTIFICATION_START;
1239 	else
1240 		return MEI_HBM_NOTIFICATION_STOP;
1241 }
1242 
1243 /**
1244  *  mei_cl_notify_req2fop - convert notification request top file operation type
1245  *
1246  * @req: hbm notification request type
1247  *
1248  * Return:  MEI_FOP_NOTIFY_START/STOP
1249  */
1250 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1251 {
1252 	if (req == MEI_HBM_NOTIFICATION_START)
1253 		return MEI_FOP_NOTIFY_START;
1254 	else
1255 		return MEI_FOP_NOTIFY_STOP;
1256 }
1257 
1258 /**
1259  * mei_cl_irq_notify - send notification request in irq_thread context
1260  *
1261  * @cl: client
1262  * @cb: callback block.
1263  * @cmpl_list: complete list.
1264  *
1265  * Return: 0 on such and error otherwise.
1266  */
1267 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1268 		      struct mei_cl_cb *cmpl_list)
1269 {
1270 	struct mei_device *dev = cl->dev;
1271 	u32 msg_slots;
1272 	int slots;
1273 	int ret;
1274 	bool request;
1275 
1276 	msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1277 	slots = mei_hbuf_empty_slots(dev);
1278 
1279 	if (slots < msg_slots)
1280 		return -EMSGSIZE;
1281 
1282 	request = mei_cl_notify_fop2req(cb->fop_type);
1283 	ret = mei_hbm_cl_notify_req(dev, cl, request);
1284 	if (ret) {
1285 		cl->status = ret;
1286 		list_move_tail(&cb->list, &cmpl_list->list);
1287 		return ret;
1288 	}
1289 
1290 	list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1291 	return 0;
1292 }
1293 
1294 /**
1295  * mei_cl_notify_request - send notification stop/start request
1296  *
1297  * @cl: host client
1298  * @fp: associate request with file
1299  * @request: 1 for start or 0 for stop
1300  *
1301  * Locking: called under "dev->device_lock" lock
1302  *
1303  * Return: 0 on such and error otherwise.
1304  */
1305 int mei_cl_notify_request(struct mei_cl *cl,
1306 			  const struct file *fp, u8 request)
1307 {
1308 	struct mei_device *dev;
1309 	struct mei_cl_cb *cb;
1310 	enum mei_cb_file_ops fop_type;
1311 	int rets;
1312 
1313 	if (WARN_ON(!cl || !cl->dev))
1314 		return -ENODEV;
1315 
1316 	dev = cl->dev;
1317 
1318 	if (!dev->hbm_f_ev_supported) {
1319 		cl_dbg(dev, cl, "notifications not supported\n");
1320 		return -EOPNOTSUPP;
1321 	}
1322 
1323 	rets = pm_runtime_get(dev->dev);
1324 	if (rets < 0 && rets != -EINPROGRESS) {
1325 		pm_runtime_put_noidle(dev->dev);
1326 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1327 		return rets;
1328 	}
1329 
1330 	fop_type = mei_cl_notify_req2fop(request);
1331 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1332 	if (!cb) {
1333 		rets = -ENOMEM;
1334 		goto out;
1335 	}
1336 
1337 	if (mei_hbuf_acquire(dev)) {
1338 		if (mei_hbm_cl_notify_req(dev, cl, request)) {
1339 			rets = -ENODEV;
1340 			goto out;
1341 		}
1342 		list_move_tail(&cb->list, &dev->ctrl_rd_list.list);
1343 	}
1344 
1345 	mutex_unlock(&dev->device_lock);
1346 	wait_event_timeout(cl->wait,
1347 			   cl->notify_en == request || !mei_cl_is_connected(cl),
1348 			   mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1349 	mutex_lock(&dev->device_lock);
1350 
1351 	if (cl->notify_en != request && !cl->status)
1352 		cl->status = -EFAULT;
1353 
1354 	rets = cl->status;
1355 
1356 out:
1357 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1358 	pm_runtime_mark_last_busy(dev->dev);
1359 	pm_runtime_put_autosuspend(dev->dev);
1360 
1361 	mei_io_cb_free(cb);
1362 	return rets;
1363 }
1364 
1365 /**
1366  * mei_cl_notify - raise notification
1367  *
1368  * @cl: host client
1369  *
1370  * Locking: called under "dev->device_lock" lock
1371  */
1372 void mei_cl_notify(struct mei_cl *cl)
1373 {
1374 	struct mei_device *dev;
1375 
1376 	if (!cl || !cl->dev)
1377 		return;
1378 
1379 	dev = cl->dev;
1380 
1381 	if (!cl->notify_en)
1382 		return;
1383 
1384 	cl_dbg(dev, cl, "notify event");
1385 	cl->notify_ev = true;
1386 	if (!mei_cl_bus_notify_event(cl))
1387 		wake_up_interruptible(&cl->ev_wait);
1388 
1389 	if (cl->ev_async)
1390 		kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1391 
1392 }
1393 
1394 /**
1395  * mei_cl_notify_get - get or wait for notification event
1396  *
1397  * @cl: host client
1398  * @block: this request is blocking
1399  * @notify_ev: true if notification event was received
1400  *
1401  * Locking: called under "dev->device_lock" lock
1402  *
1403  * Return: 0 on such and error otherwise.
1404  */
1405 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1406 {
1407 	struct mei_device *dev;
1408 	int rets;
1409 
1410 	*notify_ev = false;
1411 
1412 	if (WARN_ON(!cl || !cl->dev))
1413 		return -ENODEV;
1414 
1415 	dev = cl->dev;
1416 
1417 	if (!mei_cl_is_connected(cl))
1418 		return -ENODEV;
1419 
1420 	if (cl->notify_ev)
1421 		goto out;
1422 
1423 	if (!block)
1424 		return -EAGAIN;
1425 
1426 	mutex_unlock(&dev->device_lock);
1427 	rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1428 	mutex_lock(&dev->device_lock);
1429 
1430 	if (rets < 0)
1431 		return rets;
1432 
1433 out:
1434 	*notify_ev = cl->notify_ev;
1435 	cl->notify_ev = false;
1436 	return 0;
1437 }
1438 
1439 /**
1440  * mei_cl_read_start - the start read client message function.
1441  *
1442  * @cl: host client
1443  * @length: number of bytes to read
1444  * @fp: pointer to file structure
1445  *
1446  * Return: 0 on success, <0 on failure.
1447  */
1448 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1449 {
1450 	struct mei_device *dev;
1451 	struct mei_cl_cb *cb;
1452 	int rets;
1453 
1454 	if (WARN_ON(!cl || !cl->dev))
1455 		return -ENODEV;
1456 
1457 	dev = cl->dev;
1458 
1459 	if (!mei_cl_is_connected(cl))
1460 		return -ENODEV;
1461 
1462 	if (!mei_me_cl_is_active(cl->me_cl)) {
1463 		cl_err(dev, cl, "no such me client\n");
1464 		return  -ENOTTY;
1465 	}
1466 
1467 	if (mei_cl_is_fixed_address(cl) || cl == &dev->iamthif_cl)
1468 		return 0;
1469 
1470 	/* HW currently supports only one pending read */
1471 	if (cl->rx_flow_ctrl_creds)
1472 		return -EBUSY;
1473 
1474 	cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1475 	if (!cb)
1476 		return -ENOMEM;
1477 
1478 	rets = pm_runtime_get(dev->dev);
1479 	if (rets < 0 && rets != -EINPROGRESS) {
1480 		pm_runtime_put_noidle(dev->dev);
1481 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1482 		goto nortpm;
1483 	}
1484 
1485 	rets = 0;
1486 	if (mei_hbuf_acquire(dev)) {
1487 		rets = mei_hbm_cl_flow_control_req(dev, cl);
1488 		if (rets < 0)
1489 			goto out;
1490 
1491 		list_move_tail(&cb->list, &cl->rd_pending);
1492 	}
1493 	cl->rx_flow_ctrl_creds++;
1494 
1495 out:
1496 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1497 	pm_runtime_mark_last_busy(dev->dev);
1498 	pm_runtime_put_autosuspend(dev->dev);
1499 nortpm:
1500 	if (rets)
1501 		mei_io_cb_free(cb);
1502 
1503 	return rets;
1504 }
1505 
1506 /**
1507  * mei_cl_irq_write - write a message to device
1508  *	from the interrupt thread context
1509  *
1510  * @cl: client
1511  * @cb: callback block.
1512  * @cmpl_list: complete list.
1513  *
1514  * Return: 0, OK; otherwise error.
1515  */
1516 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1517 		     struct mei_cl_cb *cmpl_list)
1518 {
1519 	struct mei_device *dev;
1520 	struct mei_msg_data *buf;
1521 	struct mei_msg_hdr mei_hdr;
1522 	size_t len;
1523 	u32 msg_slots;
1524 	int slots;
1525 	int rets;
1526 	bool first_chunk;
1527 
1528 	if (WARN_ON(!cl || !cl->dev))
1529 		return -ENODEV;
1530 
1531 	dev = cl->dev;
1532 
1533 	buf = &cb->buf;
1534 
1535 	first_chunk = cb->buf_idx == 0;
1536 
1537 	rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1538 	if (rets < 0)
1539 		return rets;
1540 
1541 	if (rets == 0) {
1542 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1543 		return 0;
1544 	}
1545 
1546 	slots = mei_hbuf_empty_slots(dev);
1547 	len = buf->size - cb->buf_idx;
1548 	msg_slots = mei_data2slots(len);
1549 
1550 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1551 	mei_hdr.me_addr = mei_cl_me_id(cl);
1552 	mei_hdr.reserved = 0;
1553 	mei_hdr.internal = cb->internal;
1554 
1555 	if (slots >= msg_slots) {
1556 		mei_hdr.length = len;
1557 		mei_hdr.msg_complete = 1;
1558 	/* Split the message only if we can write the whole host buffer */
1559 	} else if (slots == dev->hbuf_depth) {
1560 		msg_slots = slots;
1561 		len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1562 		mei_hdr.length = len;
1563 		mei_hdr.msg_complete = 0;
1564 	} else {
1565 		/* wait for next time the host buffer is empty */
1566 		return 0;
1567 	}
1568 
1569 	cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1570 			cb->buf.size, cb->buf_idx);
1571 
1572 	rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1573 	if (rets) {
1574 		cl->status = rets;
1575 		list_move_tail(&cb->list, &cmpl_list->list);
1576 		return rets;
1577 	}
1578 
1579 	cl->status = 0;
1580 	cl->writing_state = MEI_WRITING;
1581 	cb->buf_idx += mei_hdr.length;
1582 	cb->completed = mei_hdr.msg_complete == 1;
1583 
1584 	if (first_chunk) {
1585 		if (mei_cl_tx_flow_ctrl_creds_reduce(cl))
1586 			return -EIO;
1587 	}
1588 
1589 	if (mei_hdr.msg_complete)
1590 		list_move_tail(&cb->list, &dev->write_waiting_list.list);
1591 
1592 	return 0;
1593 }
1594 
1595 /**
1596  * mei_cl_write - submit a write cb to mei device
1597  *	assumes device_lock is locked
1598  *
1599  * @cl: host client
1600  * @cb: write callback with filled data
1601  * @blocking: block until completed
1602  *
1603  * Return: number of bytes sent on success, <0 on failure.
1604  */
1605 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
1606 {
1607 	struct mei_device *dev;
1608 	struct mei_msg_data *buf;
1609 	struct mei_msg_hdr mei_hdr;
1610 	int size;
1611 	int rets;
1612 
1613 
1614 	if (WARN_ON(!cl || !cl->dev))
1615 		return -ENODEV;
1616 
1617 	if (WARN_ON(!cb))
1618 		return -EINVAL;
1619 
1620 	dev = cl->dev;
1621 
1622 	buf = &cb->buf;
1623 	size = buf->size;
1624 
1625 	cl_dbg(dev, cl, "size=%d\n", size);
1626 
1627 	rets = pm_runtime_get(dev->dev);
1628 	if (rets < 0 && rets != -EINPROGRESS) {
1629 		pm_runtime_put_noidle(dev->dev);
1630 		cl_err(dev, cl, "rpm: get failed %d\n", rets);
1631 		goto free;
1632 	}
1633 
1634 	cb->buf_idx = 0;
1635 	cl->writing_state = MEI_IDLE;
1636 
1637 	mei_hdr.host_addr = mei_cl_host_addr(cl);
1638 	mei_hdr.me_addr = mei_cl_me_id(cl);
1639 	mei_hdr.reserved = 0;
1640 	mei_hdr.msg_complete = 0;
1641 	mei_hdr.internal = cb->internal;
1642 
1643 	rets = mei_cl_tx_flow_ctrl_creds(cl);
1644 	if (rets < 0)
1645 		goto err;
1646 
1647 	if (rets == 0) {
1648 		cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1649 		rets = size;
1650 		goto out;
1651 	}
1652 	if (!mei_hbuf_acquire(dev)) {
1653 		cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1654 		rets = size;
1655 		goto out;
1656 	}
1657 
1658 	/* Check for a maximum length */
1659 	if (size > mei_hbuf_max_len(dev)) {
1660 		mei_hdr.length = mei_hbuf_max_len(dev);
1661 		mei_hdr.msg_complete = 0;
1662 	} else {
1663 		mei_hdr.length = size;
1664 		mei_hdr.msg_complete = 1;
1665 	}
1666 
1667 	rets = mei_write_message(dev, &mei_hdr, buf->data);
1668 	if (rets)
1669 		goto err;
1670 
1671 	rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1672 	if (rets)
1673 		goto err;
1674 
1675 	cl->writing_state = MEI_WRITING;
1676 	cb->buf_idx = mei_hdr.length;
1677 	cb->completed = mei_hdr.msg_complete == 1;
1678 
1679 out:
1680 	if (mei_hdr.msg_complete)
1681 		list_add_tail(&cb->list, &dev->write_waiting_list.list);
1682 	else
1683 		list_add_tail(&cb->list, &dev->write_list.list);
1684 
1685 	cb = NULL;
1686 	if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1687 
1688 		mutex_unlock(&dev->device_lock);
1689 		rets = wait_event_interruptible(cl->tx_wait,
1690 				cl->writing_state == MEI_WRITE_COMPLETE ||
1691 				(!mei_cl_is_connected(cl)));
1692 		mutex_lock(&dev->device_lock);
1693 		/* wait_event_interruptible returns -ERESTARTSYS */
1694 		if (rets) {
1695 			if (signal_pending(current))
1696 				rets = -EINTR;
1697 			goto err;
1698 		}
1699 		if (cl->writing_state != MEI_WRITE_COMPLETE) {
1700 			rets = -EFAULT;
1701 			goto err;
1702 		}
1703 	}
1704 
1705 	rets = size;
1706 err:
1707 	cl_dbg(dev, cl, "rpm: autosuspend\n");
1708 	pm_runtime_mark_last_busy(dev->dev);
1709 	pm_runtime_put_autosuspend(dev->dev);
1710 free:
1711 	mei_io_cb_free(cb);
1712 
1713 	return rets;
1714 }
1715 
1716 
1717 /**
1718  * mei_cl_complete - processes completed operation for a client
1719  *
1720  * @cl: private data of the file object.
1721  * @cb: callback block.
1722  */
1723 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1724 {
1725 	struct mei_device *dev = cl->dev;
1726 
1727 	switch (cb->fop_type) {
1728 	case MEI_FOP_WRITE:
1729 		mei_io_cb_free(cb);
1730 		cl->writing_state = MEI_WRITE_COMPLETE;
1731 		if (waitqueue_active(&cl->tx_wait)) {
1732 			wake_up_interruptible(&cl->tx_wait);
1733 		} else {
1734 			pm_runtime_mark_last_busy(dev->dev);
1735 			pm_request_autosuspend(dev->dev);
1736 		}
1737 		break;
1738 
1739 	case MEI_FOP_READ:
1740 		list_add_tail(&cb->list, &cl->rd_completed);
1741 		if (!mei_cl_is_fixed_address(cl) &&
1742 		    !WARN_ON(!cl->rx_flow_ctrl_creds))
1743 			cl->rx_flow_ctrl_creds--;
1744 		if (!mei_cl_bus_rx_event(cl))
1745 			wake_up_interruptible(&cl->rx_wait);
1746 		break;
1747 
1748 	case MEI_FOP_CONNECT:
1749 	case MEI_FOP_DISCONNECT:
1750 	case MEI_FOP_NOTIFY_STOP:
1751 	case MEI_FOP_NOTIFY_START:
1752 		if (waitqueue_active(&cl->wait))
1753 			wake_up(&cl->wait);
1754 
1755 		break;
1756 	case MEI_FOP_DISCONNECT_RSP:
1757 		mei_io_cb_free(cb);
1758 		mei_cl_set_disconnected(cl);
1759 		break;
1760 	default:
1761 		BUG_ON(0);
1762 	}
1763 }
1764 
1765 
1766 /**
1767  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1768  *
1769  * @dev: mei device
1770  */
1771 void mei_cl_all_disconnect(struct mei_device *dev)
1772 {
1773 	struct mei_cl *cl;
1774 
1775 	list_for_each_entry(cl, &dev->file_list, link)
1776 		mei_cl_set_disconnected(cl);
1777 }
1778