1 /*
2  * Copyright (c) 2016-2017, Linaro Ltd
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <linux/idr.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/list.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/platform_device.h>
24 #include <linux/regmap.h>
25 #include <linux/rpmsg.h>
26 #include <linux/sizes.h>
27 #include <linux/slab.h>
28 #include <linux/workqueue.h>
29 #include <linux/mailbox_client.h>
30 
31 #include "rpmsg_internal.h"
32 #include "qcom_glink_native.h"
33 
34 #define GLINK_NAME_SIZE		32
35 #define GLINK_VERSION_1		1
36 
37 #define RPM_GLINK_CID_MIN	1
38 #define RPM_GLINK_CID_MAX	65536
39 
40 struct glink_msg {
41 	__le16 cmd;
42 	__le16 param1;
43 	__le32 param2;
44 	u8 data[];
45 } __packed;
46 
47 /**
48  * struct glink_defer_cmd - deferred incoming control message
49  * @node:	list node
50  * @msg:	message header
51  * data:	payload of the message
52  *
53  * Copy of a received control message, to be added to @rx_queue and processed
54  * by @rx_work of @qcom_glink.
55  */
56 struct glink_defer_cmd {
57 	struct list_head node;
58 
59 	struct glink_msg msg;
60 	u8 data[];
61 };
62 
63 /**
64  * struct glink_core_rx_intent - RX intent
65  * RX intent
66  *
67  * data: pointer to the data (may be NULL for zero-copy)
68  * id: remote or local intent ID
69  * size: size of the original intent (do not modify)
70  * reuse: To mark if the intent can be reused after first use
71  * in_use: To mark if intent is already in use for the channel
72  * offset: next write offset (initially 0)
73  */
74 struct glink_core_rx_intent {
75 	void *data;
76 	u32 id;
77 	size_t size;
78 	bool reuse;
79 	bool in_use;
80 	u32 offset;
81 
82 	struct list_head node;
83 };
84 
85 /**
86  * struct qcom_glink - driver context, relates to one remote subsystem
87  * @dev:	reference to the associated struct device
88  * @mbox_client: mailbox client
89  * @mbox_chan:  mailbox channel
90  * @rx_pipe:	pipe object for receive FIFO
91  * @tx_pipe:	pipe object for transmit FIFO
92  * @irq:	IRQ for signaling incoming events
93  * @rx_work:	worker for handling received control messages
94  * @rx_lock:	protects the @rx_queue
95  * @rx_queue:	queue of received control messages to be processed in @rx_work
96  * @tx_lock:	synchronizes operations on the tx fifo
97  * @idr_lock:	synchronizes @lcids and @rcids modifications
98  * @lcids:	idr of all channels with a known local channel id
99  * @rcids:	idr of all channels with a known remote channel id
100  */
101 struct qcom_glink {
102 	struct device *dev;
103 
104 	struct mbox_client mbox_client;
105 	struct mbox_chan *mbox_chan;
106 
107 	struct qcom_glink_pipe *rx_pipe;
108 	struct qcom_glink_pipe *tx_pipe;
109 
110 	int irq;
111 
112 	struct work_struct rx_work;
113 	spinlock_t rx_lock;
114 	struct list_head rx_queue;
115 
116 	struct mutex tx_lock;
117 
118 	spinlock_t idr_lock;
119 	struct idr lcids;
120 	struct idr rcids;
121 	unsigned long features;
122 
123 	bool intentless;
124 };
125 
126 enum {
127 	GLINK_STATE_CLOSED,
128 	GLINK_STATE_OPENING,
129 	GLINK_STATE_OPEN,
130 	GLINK_STATE_CLOSING,
131 };
132 
133 /**
134  * struct glink_channel - internal representation of a channel
135  * @rpdev:	rpdev reference, only used for primary endpoints
136  * @ept:	rpmsg endpoint this channel is associated with
137  * @glink:	qcom_glink context handle
138  * @refcount:	refcount for the channel object
139  * @recv_lock:	guard for @ept.cb
140  * @name:	unique channel name/identifier
141  * @lcid:	channel id, in local space
142  * @rcid:	channel id, in remote space
143  * @intent_lock: lock for protection of @liids, @riids
144  * @liids:	idr of all local intents
145  * @riids:	idr of all remote intents
146  * @intent_work: worker responsible for transmitting rx_done packets
147  * @done_intents: list of intents that needs to be announced rx_done
148  * @buf:	receive buffer, for gathering fragments
149  * @buf_offset:	write offset in @buf
150  * @buf_size:	size of current @buf
151  * @open_ack:	completed once remote has acked the open-request
152  * @open_req:	completed once open-request has been received
153  * @intent_req_lock: Synchronises multiple intent requests
154  * @intent_req_result: Result of intent request
155  * @intent_req_comp: Completion for intent_req signalling
156  */
157 struct glink_channel {
158 	struct rpmsg_endpoint ept;
159 
160 	struct rpmsg_device *rpdev;
161 	struct qcom_glink *glink;
162 
163 	struct kref refcount;
164 
165 	spinlock_t recv_lock;
166 
167 	char *name;
168 	unsigned int lcid;
169 	unsigned int rcid;
170 
171 	spinlock_t intent_lock;
172 	struct idr liids;
173 	struct idr riids;
174 	struct work_struct intent_work;
175 	struct list_head done_intents;
176 
177 	struct glink_core_rx_intent *buf;
178 	int buf_offset;
179 	int buf_size;
180 
181 	struct completion open_ack;
182 	struct completion open_req;
183 
184 	struct mutex intent_req_lock;
185 	bool intent_req_result;
186 	struct completion intent_req_comp;
187 };
188 
189 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
190 
191 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
192 
193 #define RPM_CMD_VERSION			0
194 #define RPM_CMD_VERSION_ACK		1
195 #define RPM_CMD_OPEN			2
196 #define RPM_CMD_CLOSE			3
197 #define RPM_CMD_OPEN_ACK		4
198 #define RPM_CMD_INTENT			5
199 #define RPM_CMD_RX_DONE			6
200 #define RPM_CMD_RX_INTENT_REQ		7
201 #define RPM_CMD_RX_INTENT_REQ_ACK	8
202 #define RPM_CMD_TX_DATA			9
203 #define RPM_CMD_CLOSE_ACK		11
204 #define RPM_CMD_TX_DATA_CONT		12
205 #define RPM_CMD_READ_NOTIF		13
206 #define RPM_CMD_RX_DONE_W_REUSE		14
207 
208 #define GLINK_FEATURE_INTENTLESS	BIT(1)
209 
210 static void qcom_glink_rx_done_work(struct work_struct *work);
211 
212 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
213 						      const char *name)
214 {
215 	struct glink_channel *channel;
216 
217 	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
218 	if (!channel)
219 		return ERR_PTR(-ENOMEM);
220 
221 	/* Setup glink internal glink_channel data */
222 	spin_lock_init(&channel->recv_lock);
223 	spin_lock_init(&channel->intent_lock);
224 
225 	channel->glink = glink;
226 	channel->name = kstrdup(name, GFP_KERNEL);
227 
228 	init_completion(&channel->open_req);
229 	init_completion(&channel->open_ack);
230 	init_completion(&channel->intent_req_comp);
231 
232 	INIT_LIST_HEAD(&channel->done_intents);
233 	INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
234 
235 	idr_init(&channel->liids);
236 	idr_init(&channel->riids);
237 	kref_init(&channel->refcount);
238 
239 	return channel;
240 }
241 
242 static void qcom_glink_channel_release(struct kref *ref)
243 {
244 	struct glink_channel *channel = container_of(ref, struct glink_channel,
245 						     refcount);
246 	unsigned long flags;
247 
248 	spin_lock_irqsave(&channel->intent_lock, flags);
249 	idr_destroy(&channel->liids);
250 	idr_destroy(&channel->riids);
251 	spin_unlock_irqrestore(&channel->intent_lock, flags);
252 
253 	kfree(channel->name);
254 	kfree(channel);
255 }
256 
257 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
258 {
259 	return glink->rx_pipe->avail(glink->rx_pipe);
260 }
261 
262 static void qcom_glink_rx_peak(struct qcom_glink *glink,
263 			       void *data, unsigned int offset, size_t count)
264 {
265 	glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
266 }
267 
268 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
269 {
270 	glink->rx_pipe->advance(glink->rx_pipe, count);
271 }
272 
273 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
274 {
275 	return glink->tx_pipe->avail(glink->tx_pipe);
276 }
277 
278 static void qcom_glink_tx_write(struct qcom_glink *glink,
279 				const void *hdr, size_t hlen,
280 				const void *data, size_t dlen)
281 {
282 	glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
283 }
284 
285 static int qcom_glink_tx(struct qcom_glink *glink,
286 			 const void *hdr, size_t hlen,
287 			 const void *data, size_t dlen, bool wait)
288 {
289 	unsigned int tlen = hlen + dlen;
290 	int ret;
291 
292 	/* Reject packets that are too big */
293 	if (tlen >= glink->tx_pipe->length)
294 		return -EINVAL;
295 
296 	ret = mutex_lock_interruptible(&glink->tx_lock);
297 	if (ret)
298 		return ret;
299 
300 	while (qcom_glink_tx_avail(glink) < tlen) {
301 		if (!wait) {
302 			ret = -EAGAIN;
303 			goto out;
304 		}
305 
306 		usleep_range(10000, 15000);
307 	}
308 
309 	qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
310 
311 	mbox_send_message(glink->mbox_chan, NULL);
312 	mbox_client_txdone(glink->mbox_chan, 0);
313 
314 out:
315 	mutex_unlock(&glink->tx_lock);
316 
317 	return ret;
318 }
319 
320 static int qcom_glink_send_version(struct qcom_glink *glink)
321 {
322 	struct glink_msg msg;
323 
324 	msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
325 	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
326 	msg.param2 = cpu_to_le32(glink->features);
327 
328 	return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
329 }
330 
331 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
332 {
333 	struct glink_msg msg;
334 
335 	msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
336 	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
337 	msg.param2 = cpu_to_le32(glink->features);
338 
339 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
340 }
341 
342 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
343 				     struct glink_channel *channel)
344 {
345 	struct glink_msg msg;
346 
347 	msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
348 	msg.param1 = cpu_to_le16(channel->rcid);
349 	msg.param2 = cpu_to_le32(0);
350 
351 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
352 }
353 
354 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
355 					     unsigned int cid, bool granted)
356 {
357 	struct glink_channel *channel;
358 	unsigned long flags;
359 
360 	spin_lock_irqsave(&glink->idr_lock, flags);
361 	channel = idr_find(&glink->rcids, cid);
362 	spin_unlock_irqrestore(&glink->idr_lock, flags);
363 	if (!channel) {
364 		dev_err(glink->dev, "unable to find channel\n");
365 		return;
366 	}
367 
368 	channel->intent_req_result = granted;
369 	complete(&channel->intent_req_comp);
370 }
371 
372 /**
373  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
374  * @glink: Ptr to the glink edge
375  * @channel: Ptr to the channel that the open req is sent
376  *
377  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
378  * Will return with refcount held, regardless of outcome.
379  *
380  * Returns 0 on success, negative errno otherwise.
381  */
382 static int qcom_glink_send_open_req(struct qcom_glink *glink,
383 				    struct glink_channel *channel)
384 {
385 	struct {
386 		struct glink_msg msg;
387 		u8 name[GLINK_NAME_SIZE];
388 	} __packed req;
389 	int name_len = strlen(channel->name) + 1;
390 	int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
391 	int ret;
392 	unsigned long flags;
393 
394 	kref_get(&channel->refcount);
395 
396 	spin_lock_irqsave(&glink->idr_lock, flags);
397 	ret = idr_alloc_cyclic(&glink->lcids, channel,
398 			       RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
399 			       GFP_ATOMIC);
400 	spin_unlock_irqrestore(&glink->idr_lock, flags);
401 	if (ret < 0)
402 		return ret;
403 
404 	channel->lcid = ret;
405 
406 	req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
407 	req.msg.param1 = cpu_to_le16(channel->lcid);
408 	req.msg.param2 = cpu_to_le32(name_len);
409 	strcpy(req.name, channel->name);
410 
411 	ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
412 	if (ret)
413 		goto remove_idr;
414 
415 	return 0;
416 
417 remove_idr:
418 	spin_lock_irqsave(&glink->idr_lock, flags);
419 	idr_remove(&glink->lcids, channel->lcid);
420 	channel->lcid = 0;
421 	spin_unlock_irqrestore(&glink->idr_lock, flags);
422 
423 	return ret;
424 }
425 
426 static void qcom_glink_send_close_req(struct qcom_glink *glink,
427 				      struct glink_channel *channel)
428 {
429 	struct glink_msg req;
430 
431 	req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
432 	req.param1 = cpu_to_le16(channel->lcid);
433 	req.param2 = 0;
434 
435 	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
436 }
437 
438 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
439 				      unsigned int rcid)
440 {
441 	struct glink_msg req;
442 
443 	req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
444 	req.param1 = cpu_to_le16(rcid);
445 	req.param2 = 0;
446 
447 	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
448 }
449 
450 static void qcom_glink_rx_done_work(struct work_struct *work)
451 {
452 	struct glink_channel *channel = container_of(work, struct glink_channel,
453 						     intent_work);
454 	struct qcom_glink *glink = channel->glink;
455 	struct glink_core_rx_intent *intent, *tmp;
456 	struct {
457 		u16 id;
458 		u16 lcid;
459 		u32 liid;
460 	} __packed cmd;
461 
462 	unsigned int cid = channel->lcid;
463 	unsigned int iid;
464 	bool reuse;
465 	unsigned long flags;
466 
467 	spin_lock_irqsave(&channel->intent_lock, flags);
468 	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
469 		list_del(&intent->node);
470 		spin_unlock_irqrestore(&channel->intent_lock, flags);
471 		iid = intent->id;
472 		reuse = intent->reuse;
473 
474 		cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
475 		cmd.lcid = cid;
476 		cmd.liid = iid;
477 
478 		qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
479 		if (!reuse) {
480 			kfree(intent->data);
481 			kfree(intent);
482 		}
483 		spin_lock_irqsave(&channel->intent_lock, flags);
484 	}
485 	spin_unlock_irqrestore(&channel->intent_lock, flags);
486 }
487 
488 static void qcom_glink_rx_done(struct qcom_glink *glink,
489 			       struct glink_channel *channel,
490 			       struct glink_core_rx_intent *intent)
491 {
492 	/* We don't send RX_DONE to intentless systems */
493 	if (glink->intentless) {
494 		kfree(intent->data);
495 		kfree(intent);
496 		return;
497 	}
498 
499 	/* Take it off the tree of receive intents */
500 	if (!intent->reuse) {
501 		spin_lock(&channel->intent_lock);
502 		idr_remove(&channel->liids, intent->id);
503 		spin_unlock(&channel->intent_lock);
504 	}
505 
506 	/* Schedule the sending of a rx_done indication */
507 	spin_lock(&channel->intent_lock);
508 	list_add_tail(&intent->node, &channel->done_intents);
509 	spin_unlock(&channel->intent_lock);
510 
511 	schedule_work(&channel->intent_work);
512 }
513 
514 /**
515  * qcom_glink_receive_version() - receive version/features from remote system
516  *
517  * @glink:	pointer to transport interface
518  * @r_version:	remote version
519  * @r_features:	remote features
520  *
521  * This function is called in response to a remote-initiated version/feature
522  * negotiation sequence.
523  */
524 static void qcom_glink_receive_version(struct qcom_glink *glink,
525 				       u32 version,
526 				       u32 features)
527 {
528 	switch (version) {
529 	case 0:
530 		break;
531 	case GLINK_VERSION_1:
532 		glink->features &= features;
533 		/* FALLTHROUGH */
534 	default:
535 		qcom_glink_send_version_ack(glink);
536 		break;
537 	}
538 }
539 
540 /**
541  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
542  *
543  * @glink:	pointer to transport interface
544  * @r_version:	remote version response
545  * @r_features:	remote features response
546  *
547  * This function is called in response to a local-initiated version/feature
548  * negotiation sequence and is the counter-offer from the remote side based
549  * upon the initial version and feature set requested.
550  */
551 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
552 					   u32 version,
553 					   u32 features)
554 {
555 	switch (version) {
556 	case 0:
557 		/* Version negotiation failed */
558 		break;
559 	case GLINK_VERSION_1:
560 		if (features == glink->features)
561 			break;
562 
563 		glink->features &= features;
564 		/* FALLTHROUGH */
565 	default:
566 		qcom_glink_send_version(glink);
567 		break;
568 	}
569 }
570 
571 /**
572  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
573 				      wire format and transmit
574  * @glink:	The transport to transmit on.
575  * @channel:	The glink channel
576  * @granted:	The request response to encode.
577  *
578  * Return: 0 on success or standard Linux error code.
579  */
580 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
581 					  struct glink_channel *channel,
582 					  bool granted)
583 {
584 	struct glink_msg msg;
585 
586 	msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
587 	msg.param1 = cpu_to_le16(channel->lcid);
588 	msg.param2 = cpu_to_le32(granted);
589 
590 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
591 
592 	return 0;
593 }
594 
595 /**
596  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
597  *			   transmit
598  * @glink:	The transport to transmit on.
599  * @channel:	The local channel
600  * @size:	The intent to pass on to remote.
601  *
602  * Return: 0 on success or standard Linux error code.
603  */
604 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
605 				       struct glink_channel *channel,
606 				       struct glink_core_rx_intent *intent)
607 {
608 	struct command {
609 		u16 id;
610 		u16 lcid;
611 		u32 count;
612 		u32 size;
613 		u32 liid;
614 	} __packed;
615 	struct command cmd;
616 
617 	cmd.id = cpu_to_le16(RPM_CMD_INTENT);
618 	cmd.lcid = cpu_to_le16(channel->lcid);
619 	cmd.count = cpu_to_le32(1);
620 	cmd.size = cpu_to_le32(intent->size);
621 	cmd.liid = cpu_to_le32(intent->id);
622 
623 	qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
624 
625 	return 0;
626 }
627 
628 static struct glink_core_rx_intent *
629 qcom_glink_alloc_intent(struct qcom_glink *glink,
630 			struct glink_channel *channel,
631 			size_t size,
632 			bool reuseable)
633 {
634 	struct glink_core_rx_intent *intent;
635 	int ret;
636 	unsigned long flags;
637 
638 	intent = kzalloc(sizeof(*intent), GFP_KERNEL);
639 	if (!intent)
640 		return NULL;
641 
642 	intent->data = kzalloc(size, GFP_KERNEL);
643 	if (!intent->data)
644 		goto free_intent;
645 
646 	spin_lock_irqsave(&channel->intent_lock, flags);
647 	ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
648 	if (ret < 0) {
649 		spin_unlock_irqrestore(&channel->intent_lock, flags);
650 		goto free_data;
651 	}
652 	spin_unlock_irqrestore(&channel->intent_lock, flags);
653 
654 	intent->id = ret;
655 	intent->size = size;
656 	intent->reuse = reuseable;
657 
658 	return intent;
659 
660 free_data:
661 	kfree(intent->data);
662 free_intent:
663 	kfree(intent);
664 	return NULL;
665 }
666 
667 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
668 				      u32 cid, uint32_t iid,
669 				      bool reuse)
670 {
671 	struct glink_core_rx_intent *intent;
672 	struct glink_channel *channel;
673 	unsigned long flags;
674 
675 	spin_lock_irqsave(&glink->idr_lock, flags);
676 	channel = idr_find(&glink->rcids, cid);
677 	spin_unlock_irqrestore(&glink->idr_lock, flags);
678 	if (!channel) {
679 		dev_err(glink->dev, "invalid channel id received\n");
680 		return;
681 	}
682 
683 	spin_lock_irqsave(&channel->intent_lock, flags);
684 	intent = idr_find(&channel->riids, iid);
685 
686 	if (!intent) {
687 		spin_unlock_irqrestore(&channel->intent_lock, flags);
688 		dev_err(glink->dev, "invalid intent id received\n");
689 		return;
690 	}
691 
692 	intent->in_use = false;
693 
694 	if (!reuse) {
695 		idr_remove(&channel->riids, intent->id);
696 		kfree(intent);
697 	}
698 	spin_unlock_irqrestore(&channel->intent_lock, flags);
699 }
700 
701 /**
702  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
703  *					    from remote side
704  * if_ptr:      Pointer to the transport interface
705  * rcid:	Remote channel ID
706  * size:	size of the intent
707  *
708  * The function searches for the local channel to which the request for
709  * rx_intent has arrived and allocates and notifies the remote back
710  */
711 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
712 					 u32 cid, size_t size)
713 {
714 	struct glink_core_rx_intent *intent;
715 	struct glink_channel *channel;
716 	unsigned long flags;
717 
718 	spin_lock_irqsave(&glink->idr_lock, flags);
719 	channel = idr_find(&glink->rcids, cid);
720 	spin_unlock_irqrestore(&glink->idr_lock, flags);
721 
722 	if (!channel) {
723 		pr_err("%s channel not found for cid %d\n", __func__, cid);
724 		return;
725 	}
726 
727 	intent = qcom_glink_alloc_intent(glink, channel, size, false);
728 	if (intent)
729 		qcom_glink_advertise_intent(glink, channel, intent);
730 
731 	qcom_glink_send_intent_req_ack(glink, channel, !!intent);
732 }
733 
734 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
735 {
736 	struct glink_defer_cmd *dcmd;
737 
738 	extra = ALIGN(extra, 8);
739 
740 	if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
741 		dev_dbg(glink->dev, "Insufficient data in rx fifo");
742 		return -ENXIO;
743 	}
744 
745 	dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
746 	if (!dcmd)
747 		return -ENOMEM;
748 
749 	INIT_LIST_HEAD(&dcmd->node);
750 
751 	qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
752 
753 	spin_lock(&glink->rx_lock);
754 	list_add_tail(&dcmd->node, &glink->rx_queue);
755 	spin_unlock(&glink->rx_lock);
756 
757 	schedule_work(&glink->rx_work);
758 	qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
759 
760 	return 0;
761 }
762 
763 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
764 {
765 	struct glink_core_rx_intent *intent;
766 	struct glink_channel *channel;
767 	struct {
768 		struct glink_msg msg;
769 		__le32 chunk_size;
770 		__le32 left_size;
771 	} __packed hdr;
772 	unsigned int chunk_size;
773 	unsigned int left_size;
774 	unsigned int rcid;
775 	unsigned int liid;
776 	int ret = 0;
777 	unsigned long flags;
778 
779 	if (avail < sizeof(hdr)) {
780 		dev_dbg(glink->dev, "Not enough data in fifo\n");
781 		return -EAGAIN;
782 	}
783 
784 	qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
785 	chunk_size = le32_to_cpu(hdr.chunk_size);
786 	left_size = le32_to_cpu(hdr.left_size);
787 
788 	if (avail < sizeof(hdr) + chunk_size) {
789 		dev_dbg(glink->dev, "Payload not yet in fifo\n");
790 		return -EAGAIN;
791 	}
792 
793 	if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
794 		return -EINVAL;
795 
796 	rcid = le16_to_cpu(hdr.msg.param1);
797 	spin_lock_irqsave(&glink->idr_lock, flags);
798 	channel = idr_find(&glink->rcids, rcid);
799 	spin_unlock_irqrestore(&glink->idr_lock, flags);
800 	if (!channel) {
801 		dev_dbg(glink->dev, "Data on non-existing channel\n");
802 
803 		/* Drop the message */
804 		goto advance_rx;
805 	}
806 
807 	if (glink->intentless) {
808 		/* Might have an ongoing, fragmented, message to append */
809 		if (!channel->buf) {
810 			intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
811 			if (!intent)
812 				return -ENOMEM;
813 
814 			intent->data = kmalloc(chunk_size + left_size,
815 					       GFP_ATOMIC);
816 			if (!intent->data) {
817 				kfree(intent);
818 				return -ENOMEM;
819 			}
820 
821 			intent->id = 0xbabababa;
822 			intent->size = chunk_size + left_size;
823 			intent->offset = 0;
824 
825 			channel->buf = intent;
826 		} else {
827 			intent = channel->buf;
828 		}
829 	} else {
830 		liid = le32_to_cpu(hdr.msg.param2);
831 
832 		spin_lock_irqsave(&channel->intent_lock, flags);
833 		intent = idr_find(&channel->liids, liid);
834 		spin_unlock_irqrestore(&channel->intent_lock, flags);
835 
836 		if (!intent) {
837 			dev_err(glink->dev,
838 				"no intent found for channel %s intent %d",
839 				channel->name, liid);
840 			goto advance_rx;
841 		}
842 	}
843 
844 	if (intent->size - intent->offset < chunk_size) {
845 		dev_err(glink->dev, "Insufficient space in intent\n");
846 
847 		/* The packet header lied, drop payload */
848 		goto advance_rx;
849 	}
850 
851 	qcom_glink_rx_peak(glink, intent->data + intent->offset,
852 			   sizeof(hdr), chunk_size);
853 	intent->offset += chunk_size;
854 
855 	/* Handle message when no fragments remain to be received */
856 	if (!left_size) {
857 		spin_lock(&channel->recv_lock);
858 		if (channel->ept.cb) {
859 			channel->ept.cb(channel->ept.rpdev,
860 					intent->data,
861 					intent->offset,
862 					channel->ept.priv,
863 					RPMSG_ADDR_ANY);
864 		}
865 		spin_unlock(&channel->recv_lock);
866 
867 		intent->offset = 0;
868 		channel->buf = NULL;
869 
870 		qcom_glink_rx_done(glink, channel, intent);
871 	}
872 
873 advance_rx:
874 	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
875 
876 	return ret;
877 }
878 
879 static void qcom_glink_handle_intent(struct qcom_glink *glink,
880 				     unsigned int cid,
881 				     unsigned int count,
882 				     size_t avail)
883 {
884 	struct glink_core_rx_intent *intent;
885 	struct glink_channel *channel;
886 	struct intent_pair {
887 		__le32 size;
888 		__le32 iid;
889 	};
890 
891 	struct {
892 		struct glink_msg msg;
893 		struct intent_pair intents[];
894 	} __packed * msg;
895 
896 	const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
897 	int ret;
898 	int i;
899 	unsigned long flags;
900 
901 	if (avail < msglen) {
902 		dev_dbg(glink->dev, "Not enough data in fifo\n");
903 		return;
904 	}
905 
906 	spin_lock_irqsave(&glink->idr_lock, flags);
907 	channel = idr_find(&glink->rcids, cid);
908 	spin_unlock_irqrestore(&glink->idr_lock, flags);
909 	if (!channel) {
910 		dev_err(glink->dev, "intents for non-existing channel\n");
911 		return;
912 	}
913 
914 	msg = kmalloc(msglen, GFP_ATOMIC);
915 	if (!msg)
916 		return;
917 
918 	qcom_glink_rx_peak(glink, msg, 0, msglen);
919 
920 	for (i = 0; i < count; ++i) {
921 		intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
922 		if (!intent)
923 			break;
924 
925 		intent->id = le32_to_cpu(msg->intents[i].iid);
926 		intent->size = le32_to_cpu(msg->intents[i].size);
927 
928 		spin_lock_irqsave(&channel->intent_lock, flags);
929 		ret = idr_alloc(&channel->riids, intent,
930 				intent->id, intent->id + 1, GFP_ATOMIC);
931 		spin_unlock_irqrestore(&channel->intent_lock, flags);
932 
933 		if (ret < 0)
934 			dev_err(glink->dev, "failed to store remote intent\n");
935 	}
936 
937 	kfree(msg);
938 	qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
939 }
940 
941 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
942 {
943 	struct glink_channel *channel;
944 
945 	spin_lock(&glink->idr_lock);
946 	channel = idr_find(&glink->lcids, lcid);
947 	spin_unlock(&glink->idr_lock);
948 	if (!channel) {
949 		dev_err(glink->dev, "Invalid open ack packet\n");
950 		return -EINVAL;
951 	}
952 
953 	complete(&channel->open_ack);
954 
955 	return 0;
956 }
957 
958 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
959 {
960 	struct qcom_glink *glink = data;
961 	struct glink_msg msg;
962 	unsigned int param1;
963 	unsigned int param2;
964 	unsigned int avail;
965 	unsigned int cmd;
966 	int ret = 0;
967 
968 	for (;;) {
969 		avail = qcom_glink_rx_avail(glink);
970 		if (avail < sizeof(msg))
971 			break;
972 
973 		qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
974 
975 		cmd = le16_to_cpu(msg.cmd);
976 		param1 = le16_to_cpu(msg.param1);
977 		param2 = le32_to_cpu(msg.param2);
978 
979 		switch (cmd) {
980 		case RPM_CMD_VERSION:
981 		case RPM_CMD_VERSION_ACK:
982 		case RPM_CMD_CLOSE:
983 		case RPM_CMD_CLOSE_ACK:
984 		case RPM_CMD_RX_INTENT_REQ:
985 			ret = qcom_glink_rx_defer(glink, 0);
986 			break;
987 		case RPM_CMD_OPEN_ACK:
988 			ret = qcom_glink_rx_open_ack(glink, param1);
989 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
990 			break;
991 		case RPM_CMD_OPEN:
992 			ret = qcom_glink_rx_defer(glink, param2);
993 			break;
994 		case RPM_CMD_TX_DATA:
995 		case RPM_CMD_TX_DATA_CONT:
996 			ret = qcom_glink_rx_data(glink, avail);
997 			break;
998 		case RPM_CMD_READ_NOTIF:
999 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1000 
1001 			mbox_send_message(glink->mbox_chan, NULL);
1002 			mbox_client_txdone(glink->mbox_chan, 0);
1003 			break;
1004 		case RPM_CMD_INTENT:
1005 			qcom_glink_handle_intent(glink, param1, param2, avail);
1006 			break;
1007 		case RPM_CMD_RX_DONE:
1008 			qcom_glink_handle_rx_done(glink, param1, param2, false);
1009 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1010 			break;
1011 		case RPM_CMD_RX_DONE_W_REUSE:
1012 			qcom_glink_handle_rx_done(glink, param1, param2, true);
1013 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1014 			break;
1015 		case RPM_CMD_RX_INTENT_REQ_ACK:
1016 			qcom_glink_handle_intent_req_ack(glink, param1, param2);
1017 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1018 			break;
1019 		default:
1020 			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1021 			ret = -EINVAL;
1022 			break;
1023 		}
1024 
1025 		if (ret)
1026 			break;
1027 	}
1028 
1029 	return IRQ_HANDLED;
1030 }
1031 
1032 /* Locally initiated rpmsg_create_ept */
1033 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1034 						     const char *name)
1035 {
1036 	struct glink_channel *channel;
1037 	int ret;
1038 	unsigned long flags;
1039 
1040 	channel = qcom_glink_alloc_channel(glink, name);
1041 	if (IS_ERR(channel))
1042 		return ERR_CAST(channel);
1043 
1044 	ret = qcom_glink_send_open_req(glink, channel);
1045 	if (ret)
1046 		goto release_channel;
1047 
1048 	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1049 	if (!ret)
1050 		goto err_timeout;
1051 
1052 	ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1053 	if (!ret)
1054 		goto err_timeout;
1055 
1056 	qcom_glink_send_open_ack(glink, channel);
1057 
1058 	return channel;
1059 
1060 err_timeout:
1061 	/* qcom_glink_send_open_req() did register the channel in lcids*/
1062 	spin_lock_irqsave(&glink->idr_lock, flags);
1063 	idr_remove(&glink->lcids, channel->lcid);
1064 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1065 
1066 release_channel:
1067 	/* Release qcom_glink_send_open_req() reference */
1068 	kref_put(&channel->refcount, qcom_glink_channel_release);
1069 	/* Release qcom_glink_alloc_channel() reference */
1070 	kref_put(&channel->refcount, qcom_glink_channel_release);
1071 
1072 	return ERR_PTR(-ETIMEDOUT);
1073 }
1074 
1075 /* Remote initiated rpmsg_create_ept */
1076 static int qcom_glink_create_remote(struct qcom_glink *glink,
1077 				    struct glink_channel *channel)
1078 {
1079 	int ret;
1080 
1081 	qcom_glink_send_open_ack(glink, channel);
1082 
1083 	ret = qcom_glink_send_open_req(glink, channel);
1084 	if (ret)
1085 		goto close_link;
1086 
1087 	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1088 	if (!ret) {
1089 		ret = -ETIMEDOUT;
1090 		goto close_link;
1091 	}
1092 
1093 	return 0;
1094 
1095 close_link:
1096 	/*
1097 	 * Send a close request to "undo" our open-ack. The close-ack will
1098 	 * release the last reference.
1099 	 */
1100 	qcom_glink_send_close_req(glink, channel);
1101 
1102 	/* Release qcom_glink_send_open_req() reference */
1103 	kref_put(&channel->refcount, qcom_glink_channel_release);
1104 
1105 	return ret;
1106 }
1107 
1108 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1109 						    rpmsg_rx_cb_t cb,
1110 						    void *priv,
1111 						    struct rpmsg_channel_info
1112 									chinfo)
1113 {
1114 	struct glink_channel *parent = to_glink_channel(rpdev->ept);
1115 	struct glink_channel *channel;
1116 	struct qcom_glink *glink = parent->glink;
1117 	struct rpmsg_endpoint *ept;
1118 	const char *name = chinfo.name;
1119 	int cid;
1120 	int ret;
1121 	unsigned long flags;
1122 
1123 	spin_lock_irqsave(&glink->idr_lock, flags);
1124 	idr_for_each_entry(&glink->rcids, channel, cid) {
1125 		if (!strcmp(channel->name, name))
1126 			break;
1127 	}
1128 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1129 
1130 	if (!channel) {
1131 		channel = qcom_glink_create_local(glink, name);
1132 		if (IS_ERR(channel))
1133 			return NULL;
1134 	} else {
1135 		ret = qcom_glink_create_remote(glink, channel);
1136 		if (ret)
1137 			return NULL;
1138 	}
1139 
1140 	ept = &channel->ept;
1141 	ept->rpdev = rpdev;
1142 	ept->cb = cb;
1143 	ept->priv = priv;
1144 	ept->ops = &glink_endpoint_ops;
1145 
1146 	return ept;
1147 }
1148 
1149 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1150 {
1151 	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1152 	struct device_node *np = rpdev->dev.of_node;
1153 	struct qcom_glink *glink = channel->glink;
1154 	struct glink_core_rx_intent *intent;
1155 	const struct property *prop = NULL;
1156 	__be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1157 	int num_intents;
1158 	int num_groups = 1;
1159 	__be32 *val = defaults;
1160 	int size;
1161 
1162 	if (glink->intentless)
1163 		return 0;
1164 
1165 	prop = of_find_property(np, "qcom,intents", NULL);
1166 	if (prop) {
1167 		val = prop->value;
1168 		num_groups = prop->length / sizeof(u32) / 2;
1169 	}
1170 
1171 	/* Channel is now open, advertise base set of intents */
1172 	while (num_groups--) {
1173 		size = be32_to_cpup(val++);
1174 		num_intents = be32_to_cpup(val++);
1175 		while (num_intents--) {
1176 			intent = qcom_glink_alloc_intent(glink, channel, size,
1177 							 true);
1178 			if (!intent)
1179 				break;
1180 
1181 			qcom_glink_advertise_intent(glink, channel, intent);
1182 		}
1183 	}
1184 	return 0;
1185 }
1186 
1187 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1188 {
1189 	struct glink_channel *channel = to_glink_channel(ept);
1190 	struct qcom_glink *glink = channel->glink;
1191 	unsigned long flags;
1192 
1193 	spin_lock_irqsave(&channel->recv_lock, flags);
1194 	channel->ept.cb = NULL;
1195 	spin_unlock_irqrestore(&channel->recv_lock, flags);
1196 
1197 	/* Decouple the potential rpdev from the channel */
1198 	channel->rpdev = NULL;
1199 
1200 	qcom_glink_send_close_req(glink, channel);
1201 }
1202 
1203 static int qcom_glink_request_intent(struct qcom_glink *glink,
1204 				     struct glink_channel *channel,
1205 				     size_t size)
1206 {
1207 	struct {
1208 		u16 id;
1209 		u16 cid;
1210 		u32 size;
1211 	} __packed cmd;
1212 
1213 	int ret;
1214 
1215 	mutex_lock(&channel->intent_req_lock);
1216 
1217 	reinit_completion(&channel->intent_req_comp);
1218 
1219 	cmd.id = RPM_CMD_RX_INTENT_REQ;
1220 	cmd.cid = channel->lcid;
1221 	cmd.size = size;
1222 
1223 	ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1224 	if (ret)
1225 		goto unlock;
1226 
1227 	ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1228 	if (!ret) {
1229 		dev_err(glink->dev, "intent request timed out\n");
1230 		ret = -ETIMEDOUT;
1231 	} else {
1232 		ret = channel->intent_req_result ? 0 : -ECANCELED;
1233 	}
1234 
1235 unlock:
1236 	mutex_unlock(&channel->intent_req_lock);
1237 	return ret;
1238 }
1239 
1240 static int __qcom_glink_send(struct glink_channel *channel,
1241 			     void *data, int len, bool wait)
1242 {
1243 	struct qcom_glink *glink = channel->glink;
1244 	struct glink_core_rx_intent *intent = NULL;
1245 	struct glink_core_rx_intent *tmp;
1246 	int iid = 0;
1247 	struct {
1248 		struct glink_msg msg;
1249 		__le32 chunk_size;
1250 		__le32 left_size;
1251 	} __packed req;
1252 	int ret;
1253 	unsigned long flags;
1254 
1255 	if (!glink->intentless) {
1256 		while (!intent) {
1257 			spin_lock_irqsave(&channel->intent_lock, flags);
1258 			idr_for_each_entry(&channel->riids, tmp, iid) {
1259 				if (tmp->size >= len && !tmp->in_use) {
1260 					if (!intent)
1261 						intent = tmp;
1262 					else if (intent->size > tmp->size)
1263 						intent = tmp;
1264 					if (intent->size == len)
1265 						break;
1266 				}
1267 			}
1268 			if (intent)
1269 				intent->in_use = true;
1270 			spin_unlock_irqrestore(&channel->intent_lock, flags);
1271 
1272 			/* We found an available intent */
1273 			if (intent)
1274 				break;
1275 
1276 			if (!wait)
1277 				return -EBUSY;
1278 
1279 			ret = qcom_glink_request_intent(glink, channel, len);
1280 			if (ret < 0)
1281 				return ret;
1282 		}
1283 
1284 		iid = intent->id;
1285 	}
1286 
1287 	req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1288 	req.msg.param1 = cpu_to_le16(channel->lcid);
1289 	req.msg.param2 = cpu_to_le32(iid);
1290 	req.chunk_size = cpu_to_le32(len);
1291 	req.left_size = cpu_to_le32(0);
1292 
1293 	ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1294 
1295 	/* Mark intent available if we failed */
1296 	if (ret && intent)
1297 		intent->in_use = false;
1298 
1299 	return ret;
1300 }
1301 
1302 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1303 {
1304 	struct glink_channel *channel = to_glink_channel(ept);
1305 
1306 	return __qcom_glink_send(channel, data, len, true);
1307 }
1308 
1309 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1310 {
1311 	struct glink_channel *channel = to_glink_channel(ept);
1312 
1313 	return __qcom_glink_send(channel, data, len, false);
1314 }
1315 
1316 /*
1317  * Finds the device_node for the glink child interested in this channel.
1318  */
1319 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1320 						    const char *channel)
1321 {
1322 	struct device_node *child;
1323 	const char *name;
1324 	const char *key;
1325 	int ret;
1326 
1327 	for_each_available_child_of_node(node, child) {
1328 		key = "qcom,glink-channels";
1329 		ret = of_property_read_string(child, key, &name);
1330 		if (ret)
1331 			continue;
1332 
1333 		if (strcmp(name, channel) == 0)
1334 			return child;
1335 	}
1336 
1337 	return NULL;
1338 }
1339 
1340 static const struct rpmsg_device_ops glink_device_ops = {
1341 	.create_ept = qcom_glink_create_ept,
1342 	.announce_create = qcom_glink_announce_create,
1343 };
1344 
1345 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1346 	.destroy_ept = qcom_glink_destroy_ept,
1347 	.send = qcom_glink_send,
1348 	.trysend = qcom_glink_trysend,
1349 };
1350 
1351 static void qcom_glink_rpdev_release(struct device *dev)
1352 {
1353 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1354 	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1355 
1356 	channel->rpdev = NULL;
1357 	kfree(rpdev);
1358 }
1359 
1360 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1361 			      char *name)
1362 {
1363 	struct glink_channel *channel;
1364 	struct rpmsg_device *rpdev;
1365 	bool create_device = false;
1366 	struct device_node *node;
1367 	int lcid;
1368 	int ret;
1369 	unsigned long flags;
1370 
1371 	spin_lock_irqsave(&glink->idr_lock, flags);
1372 	idr_for_each_entry(&glink->lcids, channel, lcid) {
1373 		if (!strcmp(channel->name, name))
1374 			break;
1375 	}
1376 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1377 
1378 	if (!channel) {
1379 		channel = qcom_glink_alloc_channel(glink, name);
1380 		if (IS_ERR(channel))
1381 			return PTR_ERR(channel);
1382 
1383 		/* The opening dance was initiated by the remote */
1384 		create_device = true;
1385 	}
1386 
1387 	spin_lock_irqsave(&glink->idr_lock, flags);
1388 	ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1389 	if (ret < 0) {
1390 		dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1391 		spin_unlock_irqrestore(&glink->idr_lock, flags);
1392 		goto free_channel;
1393 	}
1394 	channel->rcid = ret;
1395 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1396 
1397 	complete(&channel->open_req);
1398 
1399 	if (create_device) {
1400 		rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1401 		if (!rpdev) {
1402 			ret = -ENOMEM;
1403 			goto rcid_remove;
1404 		}
1405 
1406 		rpdev->ept = &channel->ept;
1407 		strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1408 		rpdev->src = RPMSG_ADDR_ANY;
1409 		rpdev->dst = RPMSG_ADDR_ANY;
1410 		rpdev->ops = &glink_device_ops;
1411 
1412 		node = qcom_glink_match_channel(glink->dev->of_node, name);
1413 		rpdev->dev.of_node = node;
1414 		rpdev->dev.parent = glink->dev;
1415 		rpdev->dev.release = qcom_glink_rpdev_release;
1416 
1417 		ret = rpmsg_register_device(rpdev);
1418 		if (ret)
1419 			goto free_rpdev;
1420 
1421 		channel->rpdev = rpdev;
1422 	}
1423 
1424 	return 0;
1425 
1426 free_rpdev:
1427 	kfree(rpdev);
1428 rcid_remove:
1429 	spin_lock_irqsave(&glink->idr_lock, flags);
1430 	idr_remove(&glink->rcids, channel->rcid);
1431 	channel->rcid = 0;
1432 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1433 free_channel:
1434 	/* Release the reference, iff we took it */
1435 	if (create_device)
1436 		kref_put(&channel->refcount, qcom_glink_channel_release);
1437 
1438 	return ret;
1439 }
1440 
1441 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1442 {
1443 	struct rpmsg_channel_info chinfo;
1444 	struct glink_channel *channel;
1445 	unsigned long flags;
1446 
1447 	spin_lock_irqsave(&glink->idr_lock, flags);
1448 	channel = idr_find(&glink->rcids, rcid);
1449 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1450 	if (WARN(!channel, "close request on unknown channel\n"))
1451 		return;
1452 
1453 	/* cancel pending rx_done work */
1454 	cancel_work_sync(&channel->intent_work);
1455 
1456 	if (channel->rpdev) {
1457 		strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1458 		chinfo.src = RPMSG_ADDR_ANY;
1459 		chinfo.dst = RPMSG_ADDR_ANY;
1460 
1461 		rpmsg_unregister_device(glink->dev, &chinfo);
1462 	}
1463 
1464 	qcom_glink_send_close_ack(glink, channel->rcid);
1465 
1466 	spin_lock_irqsave(&glink->idr_lock, flags);
1467 	idr_remove(&glink->rcids, channel->rcid);
1468 	channel->rcid = 0;
1469 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1470 
1471 	kref_put(&channel->refcount, qcom_glink_channel_release);
1472 }
1473 
1474 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1475 {
1476 	struct glink_channel *channel;
1477 	unsigned long flags;
1478 
1479 	spin_lock_irqsave(&glink->idr_lock, flags);
1480 	channel = idr_find(&glink->lcids, lcid);
1481 	if (WARN(!channel, "close ack on unknown channel\n")) {
1482 		spin_unlock_irqrestore(&glink->idr_lock, flags);
1483 		return;
1484 	}
1485 
1486 	idr_remove(&glink->lcids, channel->lcid);
1487 	channel->lcid = 0;
1488 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1489 
1490 	kref_put(&channel->refcount, qcom_glink_channel_release);
1491 }
1492 
1493 static void qcom_glink_work(struct work_struct *work)
1494 {
1495 	struct qcom_glink *glink = container_of(work, struct qcom_glink,
1496 						rx_work);
1497 	struct glink_defer_cmd *dcmd;
1498 	struct glink_msg *msg;
1499 	unsigned long flags;
1500 	unsigned int param1;
1501 	unsigned int param2;
1502 	unsigned int cmd;
1503 
1504 	for (;;) {
1505 		spin_lock_irqsave(&glink->rx_lock, flags);
1506 		if (list_empty(&glink->rx_queue)) {
1507 			spin_unlock_irqrestore(&glink->rx_lock, flags);
1508 			break;
1509 		}
1510 		dcmd = list_first_entry(&glink->rx_queue,
1511 					struct glink_defer_cmd, node);
1512 		list_del(&dcmd->node);
1513 		spin_unlock_irqrestore(&glink->rx_lock, flags);
1514 
1515 		msg = &dcmd->msg;
1516 		cmd = le16_to_cpu(msg->cmd);
1517 		param1 = le16_to_cpu(msg->param1);
1518 		param2 = le32_to_cpu(msg->param2);
1519 
1520 		switch (cmd) {
1521 		case RPM_CMD_VERSION:
1522 			qcom_glink_receive_version(glink, param1, param2);
1523 			break;
1524 		case RPM_CMD_VERSION_ACK:
1525 			qcom_glink_receive_version_ack(glink, param1, param2);
1526 			break;
1527 		case RPM_CMD_OPEN:
1528 			qcom_glink_rx_open(glink, param1, msg->data);
1529 			break;
1530 		case RPM_CMD_CLOSE:
1531 			qcom_glink_rx_close(glink, param1);
1532 			break;
1533 		case RPM_CMD_CLOSE_ACK:
1534 			qcom_glink_rx_close_ack(glink, param1);
1535 			break;
1536 		case RPM_CMD_RX_INTENT_REQ:
1537 			qcom_glink_handle_intent_req(glink, param1, param2);
1538 			break;
1539 		default:
1540 			WARN(1, "Unknown defer object %d\n", cmd);
1541 			break;
1542 		}
1543 
1544 		kfree(dcmd);
1545 	}
1546 }
1547 
1548 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1549 					   unsigned long features,
1550 					   struct qcom_glink_pipe *rx,
1551 					   struct qcom_glink_pipe *tx,
1552 					   bool intentless)
1553 {
1554 	int irq;
1555 	int ret;
1556 	struct qcom_glink *glink;
1557 
1558 	glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1559 	if (!glink)
1560 		return ERR_PTR(-ENOMEM);
1561 
1562 	glink->dev = dev;
1563 	glink->tx_pipe = tx;
1564 	glink->rx_pipe = rx;
1565 
1566 	glink->features = features;
1567 	glink->intentless = intentless;
1568 
1569 	mutex_init(&glink->tx_lock);
1570 	spin_lock_init(&glink->rx_lock);
1571 	INIT_LIST_HEAD(&glink->rx_queue);
1572 	INIT_WORK(&glink->rx_work, qcom_glink_work);
1573 
1574 	spin_lock_init(&glink->idr_lock);
1575 	idr_init(&glink->lcids);
1576 	idr_init(&glink->rcids);
1577 
1578 	glink->mbox_client.dev = dev;
1579 	glink->mbox_client.knows_txdone = true;
1580 	glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1581 	if (IS_ERR(glink->mbox_chan)) {
1582 		if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1583 			dev_err(dev, "failed to acquire IPC channel\n");
1584 		return ERR_CAST(glink->mbox_chan);
1585 	}
1586 
1587 	irq = of_irq_get(dev->of_node, 0);
1588 	ret = devm_request_irq(dev, irq,
1589 			       qcom_glink_native_intr,
1590 			       IRQF_NO_SUSPEND | IRQF_SHARED,
1591 			       "glink-native", glink);
1592 	if (ret) {
1593 		dev_err(dev, "failed to request IRQ\n");
1594 		return ERR_PTR(ret);
1595 	}
1596 
1597 	glink->irq = irq;
1598 
1599 	ret = qcom_glink_send_version(glink);
1600 	if (ret)
1601 		return ERR_PTR(ret);
1602 
1603 	return glink;
1604 }
1605 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1606 
1607 static int qcom_glink_remove_device(struct device *dev, void *data)
1608 {
1609 	device_unregister(dev);
1610 
1611 	return 0;
1612 }
1613 
1614 void qcom_glink_native_remove(struct qcom_glink *glink)
1615 {
1616 	struct glink_channel *channel;
1617 	int cid;
1618 	int ret;
1619 	unsigned long flags;
1620 
1621 	disable_irq(glink->irq);
1622 	cancel_work_sync(&glink->rx_work);
1623 
1624 	ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1625 	if (ret)
1626 		dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1627 
1628 	spin_lock_irqsave(&glink->idr_lock, flags);
1629 	/* Release any defunct local channels, waiting for close-ack */
1630 	idr_for_each_entry(&glink->lcids, channel, cid)
1631 		kref_put(&channel->refcount, qcom_glink_channel_release);
1632 
1633 	idr_destroy(&glink->lcids);
1634 	idr_destroy(&glink->rcids);
1635 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1636 	mbox_free_channel(glink->mbox_chan);
1637 }
1638 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1639 
1640 void qcom_glink_native_unregister(struct qcom_glink *glink)
1641 {
1642 	device_unregister(glink->dev);
1643 }
1644 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1645 
1646 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1647 MODULE_LICENSE("GPL v2");
1648