1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2016-2017, Linaro Ltd
4  */
5 
6 #include <linux/idr.h>
7 #include <linux/interrupt.h>
8 #include <linux/io.h>
9 #include <linux/list.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/platform_device.h>
16 #include <linux/regmap.h>
17 #include <linux/rpmsg.h>
18 #include <linux/sizes.h>
19 #include <linux/slab.h>
20 #include <linux/workqueue.h>
21 #include <linux/mailbox_client.h>
22 
23 #include "rpmsg_internal.h"
24 #include "qcom_glink_native.h"
25 
26 #define GLINK_NAME_SIZE		32
27 #define GLINK_VERSION_1		1
28 
29 #define RPM_GLINK_CID_MIN	1
30 #define RPM_GLINK_CID_MAX	65536
31 
32 struct glink_msg {
33 	__le16 cmd;
34 	__le16 param1;
35 	__le32 param2;
36 	u8 data[];
37 } __packed;
38 
39 /**
40  * struct glink_defer_cmd - deferred incoming control message
41  * @node:	list node
42  * @msg:	message header
43  * @data:	payload of the message
44  *
45  * Copy of a received control message, to be added to @rx_queue and processed
46  * by @rx_work of @qcom_glink.
47  */
48 struct glink_defer_cmd {
49 	struct list_head node;
50 
51 	struct glink_msg msg;
52 	u8 data[];
53 };
54 
55 /**
56  * struct glink_core_rx_intent - RX intent
57  * RX intent
58  *
59  * @data: pointer to the data (may be NULL for zero-copy)
60  * @id: remote or local intent ID
61  * @size: size of the original intent (do not modify)
62  * @reuse: To mark if the intent can be reused after first use
63  * @in_use: To mark if intent is already in use for the channel
64  * @offset: next write offset (initially 0)
65  * @node:	list node
66  */
67 struct glink_core_rx_intent {
68 	void *data;
69 	u32 id;
70 	size_t size;
71 	bool reuse;
72 	bool in_use;
73 	u32 offset;
74 
75 	struct list_head node;
76 };
77 
78 /**
79  * struct qcom_glink - driver context, relates to one remote subsystem
80  * @dev:	reference to the associated struct device
81  * @mbox_client: mailbox client
82  * @mbox_chan:  mailbox channel
83  * @rx_pipe:	pipe object for receive FIFO
84  * @tx_pipe:	pipe object for transmit FIFO
85  * @irq:	IRQ for signaling incoming events
86  * @rx_work:	worker for handling received control messages
87  * @rx_lock:	protects the @rx_queue
88  * @rx_queue:	queue of received control messages to be processed in @rx_work
89  * @tx_lock:	synchronizes operations on the tx fifo
90  * @idr_lock:	synchronizes @lcids and @rcids modifications
91  * @lcids:	idr of all channels with a known local channel id
92  * @rcids:	idr of all channels with a known remote channel id
93  * @features:	remote features
94  * @intentless:	flag to indicate that there is no intent
95  * @tx_avail_notify: Waitqueue for pending tx tasks
96  * @sent_read_notify: flag to check cmd sent or not
97  */
98 struct qcom_glink {
99 	struct device *dev;
100 
101 	struct mbox_client mbox_client;
102 	struct mbox_chan *mbox_chan;
103 
104 	struct qcom_glink_pipe *rx_pipe;
105 	struct qcom_glink_pipe *tx_pipe;
106 
107 	int irq;
108 
109 	struct work_struct rx_work;
110 	spinlock_t rx_lock;
111 	struct list_head rx_queue;
112 
113 	spinlock_t tx_lock;
114 
115 	spinlock_t idr_lock;
116 	struct idr lcids;
117 	struct idr rcids;
118 	unsigned long features;
119 
120 	bool intentless;
121 	wait_queue_head_t tx_avail_notify;
122 	bool sent_read_notify;
123 };
124 
125 enum {
126 	GLINK_STATE_CLOSED,
127 	GLINK_STATE_OPENING,
128 	GLINK_STATE_OPEN,
129 	GLINK_STATE_CLOSING,
130 };
131 
132 /**
133  * struct glink_channel - internal representation of a channel
134  * @rpdev:	rpdev reference, only used for primary endpoints
135  * @ept:	rpmsg endpoint this channel is associated with
136  * @glink:	qcom_glink context handle
137  * @refcount:	refcount for the channel object
138  * @recv_lock:	guard for @ept.cb
139  * @name:	unique channel name/identifier
140  * @lcid:	channel id, in local space
141  * @rcid:	channel id, in remote space
142  * @intent_lock: lock for protection of @liids, @riids
143  * @liids:	idr of all local intents
144  * @riids:	idr of all remote intents
145  * @intent_work: worker responsible for transmitting rx_done packets
146  * @done_intents: list of intents that needs to be announced rx_done
147  * @buf:	receive buffer, for gathering fragments
148  * @buf_offset:	write offset in @buf
149  * @buf_size:	size of current @buf
150  * @open_ack:	completed once remote has acked the open-request
151  * @open_req:	completed once open-request has been received
152  * @intent_req_lock: Synchronises multiple intent requests
153  * @intent_req_result: Result of intent request
154  * @intent_req_comp: Completion for intent_req signalling
155  */
156 struct glink_channel {
157 	struct rpmsg_endpoint ept;
158 
159 	struct rpmsg_device *rpdev;
160 	struct qcom_glink *glink;
161 
162 	struct kref refcount;
163 
164 	spinlock_t recv_lock;
165 
166 	char *name;
167 	unsigned int lcid;
168 	unsigned int rcid;
169 
170 	spinlock_t intent_lock;
171 	struct idr liids;
172 	struct idr riids;
173 	struct work_struct intent_work;
174 	struct list_head done_intents;
175 
176 	struct glink_core_rx_intent *buf;
177 	int buf_offset;
178 	int buf_size;
179 
180 	struct completion open_ack;
181 	struct completion open_req;
182 
183 	struct mutex intent_req_lock;
184 	bool intent_req_result;
185 	struct completion intent_req_comp;
186 };
187 
188 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
189 
190 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
191 
192 #define RPM_CMD_VERSION			0
193 #define RPM_CMD_VERSION_ACK		1
194 #define RPM_CMD_OPEN			2
195 #define RPM_CMD_CLOSE			3
196 #define RPM_CMD_OPEN_ACK		4
197 #define RPM_CMD_INTENT			5
198 #define RPM_CMD_RX_DONE			6
199 #define RPM_CMD_RX_INTENT_REQ		7
200 #define RPM_CMD_RX_INTENT_REQ_ACK	8
201 #define RPM_CMD_TX_DATA			9
202 #define RPM_CMD_CLOSE_ACK		11
203 #define RPM_CMD_TX_DATA_CONT		12
204 #define RPM_CMD_READ_NOTIF		13
205 #define RPM_CMD_RX_DONE_W_REUSE		14
206 
207 #define GLINK_FEATURE_INTENTLESS	BIT(1)
208 
209 static void qcom_glink_rx_done_work(struct work_struct *work);
210 
211 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
212 						      const char *name)
213 {
214 	struct glink_channel *channel;
215 
216 	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
217 	if (!channel)
218 		return ERR_PTR(-ENOMEM);
219 
220 	/* Setup glink internal glink_channel data */
221 	spin_lock_init(&channel->recv_lock);
222 	spin_lock_init(&channel->intent_lock);
223 	mutex_init(&channel->intent_req_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 	struct glink_core_rx_intent *intent;
247 	struct glink_core_rx_intent *tmp;
248 	unsigned long flags;
249 	int iid;
250 
251 	/* cancel pending rx_done work */
252 	cancel_work_sync(&channel->intent_work);
253 
254 	spin_lock_irqsave(&channel->intent_lock, flags);
255 	/* Free all non-reuse intents pending rx_done work */
256 	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
257 		if (!intent->reuse) {
258 			kfree(intent->data);
259 			kfree(intent);
260 		}
261 	}
262 
263 	idr_for_each_entry(&channel->liids, tmp, iid) {
264 		kfree(tmp->data);
265 		kfree(tmp);
266 	}
267 	idr_destroy(&channel->liids);
268 
269 	idr_for_each_entry(&channel->riids, tmp, iid)
270 		kfree(tmp);
271 	idr_destroy(&channel->riids);
272 	spin_unlock_irqrestore(&channel->intent_lock, flags);
273 
274 	kfree(channel->name);
275 	kfree(channel);
276 }
277 
278 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
279 {
280 	return glink->rx_pipe->avail(glink->rx_pipe);
281 }
282 
283 static void qcom_glink_rx_peak(struct qcom_glink *glink,
284 			       void *data, unsigned int offset, size_t count)
285 {
286 	glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
287 }
288 
289 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
290 {
291 	glink->rx_pipe->advance(glink->rx_pipe, count);
292 }
293 
294 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
295 {
296 	return glink->tx_pipe->avail(glink->tx_pipe);
297 }
298 
299 static void qcom_glink_tx_write(struct qcom_glink *glink,
300 				const void *hdr, size_t hlen,
301 				const void *data, size_t dlen)
302 {
303 	glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
304 }
305 
306 static void qcom_glink_send_read_notify(struct qcom_glink *glink)
307 {
308 	struct glink_msg msg;
309 
310 	msg.cmd = cpu_to_le16(RPM_CMD_READ_NOTIF);
311 	msg.param1 = 0;
312 	msg.param2 = 0;
313 
314 	qcom_glink_tx_write(glink, &msg, sizeof(msg), NULL, 0);
315 
316 	mbox_send_message(glink->mbox_chan, NULL);
317 	mbox_client_txdone(glink->mbox_chan, 0);
318 }
319 
320 static int qcom_glink_tx(struct qcom_glink *glink,
321 			 const void *hdr, size_t hlen,
322 			 const void *data, size_t dlen, bool wait)
323 {
324 	unsigned int tlen = hlen + dlen;
325 	unsigned long flags;
326 	int ret = 0;
327 
328 	/* Reject packets that are too big */
329 	if (tlen >= glink->tx_pipe->length)
330 		return -EINVAL;
331 
332 	spin_lock_irqsave(&glink->tx_lock, flags);
333 
334 	while (qcom_glink_tx_avail(glink) < tlen) {
335 		if (!wait) {
336 			ret = -EAGAIN;
337 			goto out;
338 		}
339 
340 		if (!glink->sent_read_notify) {
341 			glink->sent_read_notify = true;
342 			qcom_glink_send_read_notify(glink);
343 		}
344 
345 		/* Wait without holding the tx_lock */
346 		spin_unlock_irqrestore(&glink->tx_lock, flags);
347 
348 		wait_event_timeout(glink->tx_avail_notify,
349 				   qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
350 
351 		spin_lock_irqsave(&glink->tx_lock, flags);
352 
353 		if (qcom_glink_tx_avail(glink) >= tlen)
354 			glink->sent_read_notify = false;
355 	}
356 
357 	qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
358 
359 	mbox_send_message(glink->mbox_chan, NULL);
360 	mbox_client_txdone(glink->mbox_chan, 0);
361 
362 out:
363 	spin_unlock_irqrestore(&glink->tx_lock, flags);
364 
365 	return ret;
366 }
367 
368 static int qcom_glink_send_version(struct qcom_glink *glink)
369 {
370 	struct glink_msg msg;
371 
372 	msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
373 	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
374 	msg.param2 = cpu_to_le32(glink->features);
375 
376 	return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
377 }
378 
379 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
380 {
381 	struct glink_msg msg;
382 
383 	msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
384 	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
385 	msg.param2 = cpu_to_le32(glink->features);
386 
387 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
388 }
389 
390 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
391 				     struct glink_channel *channel)
392 {
393 	struct glink_msg msg;
394 
395 	msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
396 	msg.param1 = cpu_to_le16(channel->rcid);
397 	msg.param2 = cpu_to_le32(0);
398 
399 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
400 }
401 
402 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
403 					     unsigned int cid, bool granted)
404 {
405 	struct glink_channel *channel;
406 	unsigned long flags;
407 
408 	spin_lock_irqsave(&glink->idr_lock, flags);
409 	channel = idr_find(&glink->rcids, cid);
410 	spin_unlock_irqrestore(&glink->idr_lock, flags);
411 	if (!channel) {
412 		dev_err(glink->dev, "unable to find channel\n");
413 		return;
414 	}
415 
416 	channel->intent_req_result = granted;
417 	complete(&channel->intent_req_comp);
418 }
419 
420 /**
421  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
422  * @glink: Ptr to the glink edge
423  * @channel: Ptr to the channel that the open req is sent
424  *
425  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
426  * Will return with refcount held, regardless of outcome.
427  *
428  * Return: 0 on success, negative errno otherwise.
429  */
430 static int qcom_glink_send_open_req(struct qcom_glink *glink,
431 				    struct glink_channel *channel)
432 {
433 	struct {
434 		struct glink_msg msg;
435 		u8 name[GLINK_NAME_SIZE];
436 	} __packed req;
437 	int name_len = strlen(channel->name) + 1;
438 	int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
439 	int ret;
440 	unsigned long flags;
441 
442 	kref_get(&channel->refcount);
443 
444 	spin_lock_irqsave(&glink->idr_lock, flags);
445 	ret = idr_alloc_cyclic(&glink->lcids, channel,
446 			       RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
447 			       GFP_ATOMIC);
448 	spin_unlock_irqrestore(&glink->idr_lock, flags);
449 	if (ret < 0)
450 		return ret;
451 
452 	channel->lcid = ret;
453 
454 	req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
455 	req.msg.param1 = cpu_to_le16(channel->lcid);
456 	req.msg.param2 = cpu_to_le32(name_len);
457 	strcpy(req.name, channel->name);
458 
459 	ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
460 	if (ret)
461 		goto remove_idr;
462 
463 	return 0;
464 
465 remove_idr:
466 	spin_lock_irqsave(&glink->idr_lock, flags);
467 	idr_remove(&glink->lcids, channel->lcid);
468 	channel->lcid = 0;
469 	spin_unlock_irqrestore(&glink->idr_lock, flags);
470 
471 	return ret;
472 }
473 
474 static void qcom_glink_send_close_req(struct qcom_glink *glink,
475 				      struct glink_channel *channel)
476 {
477 	struct glink_msg req;
478 
479 	req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
480 	req.param1 = cpu_to_le16(channel->lcid);
481 	req.param2 = 0;
482 
483 	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
484 }
485 
486 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
487 				      unsigned int rcid)
488 {
489 	struct glink_msg req;
490 
491 	req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
492 	req.param1 = cpu_to_le16(rcid);
493 	req.param2 = 0;
494 
495 	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
496 }
497 
498 static void qcom_glink_rx_done_work(struct work_struct *work)
499 {
500 	struct glink_channel *channel = container_of(work, struct glink_channel,
501 						     intent_work);
502 	struct qcom_glink *glink = channel->glink;
503 	struct glink_core_rx_intent *intent, *tmp;
504 	struct {
505 		u16 id;
506 		u16 lcid;
507 		u32 liid;
508 	} __packed cmd;
509 
510 	unsigned int cid = channel->lcid;
511 	unsigned int iid;
512 	bool reuse;
513 	unsigned long flags;
514 
515 	spin_lock_irqsave(&channel->intent_lock, flags);
516 	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
517 		list_del(&intent->node);
518 		spin_unlock_irqrestore(&channel->intent_lock, flags);
519 		iid = intent->id;
520 		reuse = intent->reuse;
521 
522 		cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
523 		cmd.lcid = cid;
524 		cmd.liid = iid;
525 
526 		qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
527 		if (!reuse) {
528 			kfree(intent->data);
529 			kfree(intent);
530 		}
531 		spin_lock_irqsave(&channel->intent_lock, flags);
532 	}
533 	spin_unlock_irqrestore(&channel->intent_lock, flags);
534 }
535 
536 static void qcom_glink_rx_done(struct qcom_glink *glink,
537 			       struct glink_channel *channel,
538 			       struct glink_core_rx_intent *intent)
539 {
540 	/* We don't send RX_DONE to intentless systems */
541 	if (glink->intentless) {
542 		kfree(intent->data);
543 		kfree(intent);
544 		return;
545 	}
546 
547 	/* Take it off the tree of receive intents */
548 	if (!intent->reuse) {
549 		spin_lock(&channel->intent_lock);
550 		idr_remove(&channel->liids, intent->id);
551 		spin_unlock(&channel->intent_lock);
552 	}
553 
554 	/* Schedule the sending of a rx_done indication */
555 	spin_lock(&channel->intent_lock);
556 	list_add_tail(&intent->node, &channel->done_intents);
557 	spin_unlock(&channel->intent_lock);
558 
559 	schedule_work(&channel->intent_work);
560 }
561 
562 /**
563  * qcom_glink_receive_version() - receive version/features from remote system
564  *
565  * @glink:	pointer to transport interface
566  * @version:	remote version
567  * @features:	remote features
568  *
569  * This function is called in response to a remote-initiated version/feature
570  * negotiation sequence.
571  */
572 static void qcom_glink_receive_version(struct qcom_glink *glink,
573 				       u32 version,
574 				       u32 features)
575 {
576 	switch (version) {
577 	case 0:
578 		break;
579 	case GLINK_VERSION_1:
580 		glink->features &= features;
581 		fallthrough;
582 	default:
583 		qcom_glink_send_version_ack(glink);
584 		break;
585 	}
586 }
587 
588 /**
589  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
590  *
591  * @glink:	pointer to transport interface
592  * @version:	remote version response
593  * @features:	remote features response
594  *
595  * This function is called in response to a local-initiated version/feature
596  * negotiation sequence and is the counter-offer from the remote side based
597  * upon the initial version and feature set requested.
598  */
599 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
600 					   u32 version,
601 					   u32 features)
602 {
603 	switch (version) {
604 	case 0:
605 		/* Version negotiation failed */
606 		break;
607 	case GLINK_VERSION_1:
608 		if (features == glink->features)
609 			break;
610 
611 		glink->features &= features;
612 		fallthrough;
613 	default:
614 		qcom_glink_send_version(glink);
615 		break;
616 	}
617 }
618 
619 /**
620  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
621  * 	wire format and transmit
622  * @glink:	The transport to transmit on.
623  * @channel:	The glink channel
624  * @granted:	The request response to encode.
625  *
626  * Return: 0 on success or standard Linux error code.
627  */
628 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
629 					  struct glink_channel *channel,
630 					  bool granted)
631 {
632 	struct glink_msg msg;
633 
634 	msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
635 	msg.param1 = cpu_to_le16(channel->lcid);
636 	msg.param2 = cpu_to_le32(granted);
637 
638 	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
639 
640 	return 0;
641 }
642 
643 /**
644  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
645  *			   transmit
646  * @glink:	The transport to transmit on.
647  * @channel:	The local channel
648  * @intent:	The intent to pass on to remote.
649  *
650  * Return: 0 on success or standard Linux error code.
651  */
652 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
653 				       struct glink_channel *channel,
654 				       struct glink_core_rx_intent *intent)
655 {
656 	struct command {
657 		__le16 id;
658 		__le16 lcid;
659 		__le32 count;
660 		__le32 size;
661 		__le32 liid;
662 	} __packed;
663 	struct command cmd;
664 
665 	cmd.id = cpu_to_le16(RPM_CMD_INTENT);
666 	cmd.lcid = cpu_to_le16(channel->lcid);
667 	cmd.count = cpu_to_le32(1);
668 	cmd.size = cpu_to_le32(intent->size);
669 	cmd.liid = cpu_to_le32(intent->id);
670 
671 	qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
672 
673 	return 0;
674 }
675 
676 static struct glink_core_rx_intent *
677 qcom_glink_alloc_intent(struct qcom_glink *glink,
678 			struct glink_channel *channel,
679 			size_t size,
680 			bool reuseable)
681 {
682 	struct glink_core_rx_intent *intent;
683 	int ret;
684 	unsigned long flags;
685 
686 	intent = kzalloc(sizeof(*intent), GFP_KERNEL);
687 	if (!intent)
688 		return NULL;
689 
690 	intent->data = kzalloc(size, GFP_KERNEL);
691 	if (!intent->data)
692 		goto free_intent;
693 
694 	spin_lock_irqsave(&channel->intent_lock, flags);
695 	ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
696 	if (ret < 0) {
697 		spin_unlock_irqrestore(&channel->intent_lock, flags);
698 		goto free_data;
699 	}
700 	spin_unlock_irqrestore(&channel->intent_lock, flags);
701 
702 	intent->id = ret;
703 	intent->size = size;
704 	intent->reuse = reuseable;
705 
706 	return intent;
707 
708 free_data:
709 	kfree(intent->data);
710 free_intent:
711 	kfree(intent);
712 	return NULL;
713 }
714 
715 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
716 				      u32 cid, uint32_t iid,
717 				      bool reuse)
718 {
719 	struct glink_core_rx_intent *intent;
720 	struct glink_channel *channel;
721 	unsigned long flags;
722 
723 	spin_lock_irqsave(&glink->idr_lock, flags);
724 	channel = idr_find(&glink->rcids, cid);
725 	spin_unlock_irqrestore(&glink->idr_lock, flags);
726 	if (!channel) {
727 		dev_err(glink->dev, "invalid channel id received\n");
728 		return;
729 	}
730 
731 	spin_lock_irqsave(&channel->intent_lock, flags);
732 	intent = idr_find(&channel->riids, iid);
733 
734 	if (!intent) {
735 		spin_unlock_irqrestore(&channel->intent_lock, flags);
736 		dev_err(glink->dev, "invalid intent id received\n");
737 		return;
738 	}
739 
740 	intent->in_use = false;
741 
742 	if (!reuse) {
743 		idr_remove(&channel->riids, intent->id);
744 		kfree(intent);
745 	}
746 	spin_unlock_irqrestore(&channel->intent_lock, flags);
747 }
748 
749 /**
750  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
751  *					    from remote side
752  * @glink:      Pointer to the transport interface
753  * @cid:	Remote channel ID
754  * @size:	size of the intent
755  *
756  * The function searches for the local channel to which the request for
757  * rx_intent has arrived and allocates and notifies the remote back
758  */
759 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
760 					 u32 cid, size_t size)
761 {
762 	struct glink_core_rx_intent *intent;
763 	struct glink_channel *channel;
764 	unsigned long flags;
765 
766 	spin_lock_irqsave(&glink->idr_lock, flags);
767 	channel = idr_find(&glink->rcids, cid);
768 	spin_unlock_irqrestore(&glink->idr_lock, flags);
769 
770 	if (!channel) {
771 		pr_err("%s channel not found for cid %d\n", __func__, cid);
772 		return;
773 	}
774 
775 	intent = qcom_glink_alloc_intent(glink, channel, size, false);
776 	if (intent)
777 		qcom_glink_advertise_intent(glink, channel, intent);
778 
779 	qcom_glink_send_intent_req_ack(glink, channel, !!intent);
780 }
781 
782 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
783 {
784 	struct glink_defer_cmd *dcmd;
785 
786 	extra = ALIGN(extra, 8);
787 
788 	if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
789 		dev_dbg(glink->dev, "Insufficient data in rx fifo");
790 		return -ENXIO;
791 	}
792 
793 	dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
794 	if (!dcmd)
795 		return -ENOMEM;
796 
797 	INIT_LIST_HEAD(&dcmd->node);
798 
799 	qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
800 
801 	spin_lock(&glink->rx_lock);
802 	list_add_tail(&dcmd->node, &glink->rx_queue);
803 	spin_unlock(&glink->rx_lock);
804 
805 	schedule_work(&glink->rx_work);
806 	qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
807 
808 	return 0;
809 }
810 
811 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
812 {
813 	struct glink_core_rx_intent *intent;
814 	struct glink_channel *channel;
815 	struct {
816 		struct glink_msg msg;
817 		__le32 chunk_size;
818 		__le32 left_size;
819 	} __packed hdr;
820 	unsigned int chunk_size;
821 	unsigned int left_size;
822 	unsigned int rcid;
823 	unsigned int liid;
824 	int ret = 0;
825 	unsigned long flags;
826 
827 	if (avail < sizeof(hdr)) {
828 		dev_dbg(glink->dev, "Not enough data in fifo\n");
829 		return -EAGAIN;
830 	}
831 
832 	qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
833 	chunk_size = le32_to_cpu(hdr.chunk_size);
834 	left_size = le32_to_cpu(hdr.left_size);
835 
836 	if (avail < sizeof(hdr) + chunk_size) {
837 		dev_dbg(glink->dev, "Payload not yet in fifo\n");
838 		return -EAGAIN;
839 	}
840 
841 	rcid = le16_to_cpu(hdr.msg.param1);
842 	spin_lock_irqsave(&glink->idr_lock, flags);
843 	channel = idr_find(&glink->rcids, rcid);
844 	spin_unlock_irqrestore(&glink->idr_lock, flags);
845 	if (!channel) {
846 		dev_dbg(glink->dev, "Data on non-existing channel\n");
847 
848 		/* Drop the message */
849 		goto advance_rx;
850 	}
851 
852 	if (glink->intentless) {
853 		/* Might have an ongoing, fragmented, message to append */
854 		if (!channel->buf) {
855 			intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
856 			if (!intent)
857 				return -ENOMEM;
858 
859 			intent->data = kmalloc(chunk_size + left_size,
860 					       GFP_ATOMIC);
861 			if (!intent->data) {
862 				kfree(intent);
863 				return -ENOMEM;
864 			}
865 
866 			intent->id = 0xbabababa;
867 			intent->size = chunk_size + left_size;
868 			intent->offset = 0;
869 
870 			channel->buf = intent;
871 		} else {
872 			intent = channel->buf;
873 		}
874 	} else {
875 		liid = le32_to_cpu(hdr.msg.param2);
876 
877 		spin_lock_irqsave(&channel->intent_lock, flags);
878 		intent = idr_find(&channel->liids, liid);
879 		spin_unlock_irqrestore(&channel->intent_lock, flags);
880 
881 		if (!intent) {
882 			dev_err(glink->dev,
883 				"no intent found for channel %s intent %d",
884 				channel->name, liid);
885 			ret = -ENOENT;
886 			goto advance_rx;
887 		}
888 	}
889 
890 	if (intent->size - intent->offset < chunk_size) {
891 		dev_err(glink->dev, "Insufficient space in intent\n");
892 
893 		/* The packet header lied, drop payload */
894 		goto advance_rx;
895 	}
896 
897 	qcom_glink_rx_peak(glink, intent->data + intent->offset,
898 			   sizeof(hdr), chunk_size);
899 	intent->offset += chunk_size;
900 
901 	/* Handle message when no fragments remain to be received */
902 	if (!left_size) {
903 		spin_lock(&channel->recv_lock);
904 		if (channel->ept.cb) {
905 			channel->ept.cb(channel->ept.rpdev,
906 					intent->data,
907 					intent->offset,
908 					channel->ept.priv,
909 					RPMSG_ADDR_ANY);
910 		}
911 		spin_unlock(&channel->recv_lock);
912 
913 		intent->offset = 0;
914 		channel->buf = NULL;
915 
916 		qcom_glink_rx_done(glink, channel, intent);
917 	}
918 
919 advance_rx:
920 	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
921 
922 	return ret;
923 }
924 
925 static void qcom_glink_handle_intent(struct qcom_glink *glink,
926 				     unsigned int cid,
927 				     unsigned int count,
928 				     size_t avail)
929 {
930 	struct glink_core_rx_intent *intent;
931 	struct glink_channel *channel;
932 	struct intent_pair {
933 		__le32 size;
934 		__le32 iid;
935 	};
936 
937 	struct {
938 		struct glink_msg msg;
939 		struct intent_pair intents[];
940 	} __packed * msg;
941 
942 	const size_t msglen = struct_size(msg, intents, count);
943 	int ret;
944 	int i;
945 	unsigned long flags;
946 
947 	if (avail < msglen) {
948 		dev_dbg(glink->dev, "Not enough data in fifo\n");
949 		return;
950 	}
951 
952 	spin_lock_irqsave(&glink->idr_lock, flags);
953 	channel = idr_find(&glink->rcids, cid);
954 	spin_unlock_irqrestore(&glink->idr_lock, flags);
955 	if (!channel) {
956 		dev_err(glink->dev, "intents for non-existing channel\n");
957 		return;
958 	}
959 
960 	msg = kmalloc(msglen, GFP_ATOMIC);
961 	if (!msg)
962 		return;
963 
964 	qcom_glink_rx_peak(glink, msg, 0, msglen);
965 
966 	for (i = 0; i < count; ++i) {
967 		intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
968 		if (!intent)
969 			break;
970 
971 		intent->id = le32_to_cpu(msg->intents[i].iid);
972 		intent->size = le32_to_cpu(msg->intents[i].size);
973 
974 		spin_lock_irqsave(&channel->intent_lock, flags);
975 		ret = idr_alloc(&channel->riids, intent,
976 				intent->id, intent->id + 1, GFP_ATOMIC);
977 		spin_unlock_irqrestore(&channel->intent_lock, flags);
978 
979 		if (ret < 0)
980 			dev_err(glink->dev, "failed to store remote intent\n");
981 	}
982 
983 	kfree(msg);
984 	qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
985 }
986 
987 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
988 {
989 	struct glink_channel *channel;
990 
991 	spin_lock(&glink->idr_lock);
992 	channel = idr_find(&glink->lcids, lcid);
993 	spin_unlock(&glink->idr_lock);
994 	if (!channel) {
995 		dev_err(glink->dev, "Invalid open ack packet\n");
996 		return -EINVAL;
997 	}
998 
999 	complete_all(&channel->open_ack);
1000 
1001 	return 0;
1002 }
1003 
1004 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
1005 {
1006 	struct qcom_glink *glink = data;
1007 	struct glink_msg msg;
1008 	unsigned int param1;
1009 	unsigned int param2;
1010 	unsigned int avail;
1011 	unsigned int cmd;
1012 	int ret = 0;
1013 
1014 	/* To wakeup any blocking writers */
1015 	wake_up_all(&glink->tx_avail_notify);
1016 
1017 	for (;;) {
1018 		avail = qcom_glink_rx_avail(glink);
1019 		if (avail < sizeof(msg))
1020 			break;
1021 
1022 		qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
1023 
1024 		cmd = le16_to_cpu(msg.cmd);
1025 		param1 = le16_to_cpu(msg.param1);
1026 		param2 = le32_to_cpu(msg.param2);
1027 
1028 		switch (cmd) {
1029 		case RPM_CMD_VERSION:
1030 		case RPM_CMD_VERSION_ACK:
1031 		case RPM_CMD_CLOSE:
1032 		case RPM_CMD_CLOSE_ACK:
1033 		case RPM_CMD_RX_INTENT_REQ:
1034 			ret = qcom_glink_rx_defer(glink, 0);
1035 			break;
1036 		case RPM_CMD_OPEN_ACK:
1037 			ret = qcom_glink_rx_open_ack(glink, param1);
1038 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1039 			break;
1040 		case RPM_CMD_OPEN:
1041 			ret = qcom_glink_rx_defer(glink, param2);
1042 			break;
1043 		case RPM_CMD_TX_DATA:
1044 		case RPM_CMD_TX_DATA_CONT:
1045 			ret = qcom_glink_rx_data(glink, avail);
1046 			break;
1047 		case RPM_CMD_READ_NOTIF:
1048 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1049 
1050 			mbox_send_message(glink->mbox_chan, NULL);
1051 			mbox_client_txdone(glink->mbox_chan, 0);
1052 			break;
1053 		case RPM_CMD_INTENT:
1054 			qcom_glink_handle_intent(glink, param1, param2, avail);
1055 			break;
1056 		case RPM_CMD_RX_DONE:
1057 			qcom_glink_handle_rx_done(glink, param1, param2, false);
1058 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1059 			break;
1060 		case RPM_CMD_RX_DONE_W_REUSE:
1061 			qcom_glink_handle_rx_done(glink, param1, param2, true);
1062 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1063 			break;
1064 		case RPM_CMD_RX_INTENT_REQ_ACK:
1065 			qcom_glink_handle_intent_req_ack(glink, param1, param2);
1066 			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1067 			break;
1068 		default:
1069 			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1070 			ret = -EINVAL;
1071 			break;
1072 		}
1073 
1074 		if (ret)
1075 			break;
1076 	}
1077 
1078 	return IRQ_HANDLED;
1079 }
1080 
1081 /* Locally initiated rpmsg_create_ept */
1082 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1083 						     const char *name)
1084 {
1085 	struct glink_channel *channel;
1086 	int ret;
1087 	unsigned long flags;
1088 
1089 	channel = qcom_glink_alloc_channel(glink, name);
1090 	if (IS_ERR(channel))
1091 		return ERR_CAST(channel);
1092 
1093 	ret = qcom_glink_send_open_req(glink, channel);
1094 	if (ret)
1095 		goto release_channel;
1096 
1097 	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1098 	if (!ret)
1099 		goto err_timeout;
1100 
1101 	ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1102 	if (!ret)
1103 		goto err_timeout;
1104 
1105 	qcom_glink_send_open_ack(glink, channel);
1106 
1107 	return channel;
1108 
1109 err_timeout:
1110 	/* qcom_glink_send_open_req() did register the channel in lcids*/
1111 	spin_lock_irqsave(&glink->idr_lock, flags);
1112 	idr_remove(&glink->lcids, channel->lcid);
1113 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1114 
1115 release_channel:
1116 	/* Release qcom_glink_send_open_req() reference */
1117 	kref_put(&channel->refcount, qcom_glink_channel_release);
1118 	/* Release qcom_glink_alloc_channel() reference */
1119 	kref_put(&channel->refcount, qcom_glink_channel_release);
1120 
1121 	return ERR_PTR(-ETIMEDOUT);
1122 }
1123 
1124 /* Remote initiated rpmsg_create_ept */
1125 static int qcom_glink_create_remote(struct qcom_glink *glink,
1126 				    struct glink_channel *channel)
1127 {
1128 	int ret;
1129 
1130 	qcom_glink_send_open_ack(glink, channel);
1131 
1132 	ret = qcom_glink_send_open_req(glink, channel);
1133 	if (ret)
1134 		goto close_link;
1135 
1136 	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1137 	if (!ret) {
1138 		ret = -ETIMEDOUT;
1139 		goto close_link;
1140 	}
1141 
1142 	return 0;
1143 
1144 close_link:
1145 	/*
1146 	 * Send a close request to "undo" our open-ack. The close-ack will
1147 	 * release qcom_glink_send_open_req() reference and the last reference
1148 	 * will be relesed after receiving remote_close or transport unregister
1149 	 * by calling qcom_glink_native_remove().
1150 	 */
1151 	qcom_glink_send_close_req(glink, channel);
1152 
1153 	return ret;
1154 }
1155 
1156 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1157 						    rpmsg_rx_cb_t cb,
1158 						    void *priv,
1159 						    struct rpmsg_channel_info
1160 									chinfo)
1161 {
1162 	struct glink_channel *parent = to_glink_channel(rpdev->ept);
1163 	struct glink_channel *channel;
1164 	struct qcom_glink *glink = parent->glink;
1165 	struct rpmsg_endpoint *ept;
1166 	const char *name = chinfo.name;
1167 	int cid;
1168 	int ret;
1169 	unsigned long flags;
1170 
1171 	spin_lock_irqsave(&glink->idr_lock, flags);
1172 	idr_for_each_entry(&glink->rcids, channel, cid) {
1173 		if (!strcmp(channel->name, name))
1174 			break;
1175 	}
1176 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1177 
1178 	if (!channel) {
1179 		channel = qcom_glink_create_local(glink, name);
1180 		if (IS_ERR(channel))
1181 			return NULL;
1182 	} else {
1183 		ret = qcom_glink_create_remote(glink, channel);
1184 		if (ret)
1185 			return NULL;
1186 	}
1187 
1188 	ept = &channel->ept;
1189 	ept->rpdev = rpdev;
1190 	ept->cb = cb;
1191 	ept->priv = priv;
1192 	ept->ops = &glink_endpoint_ops;
1193 
1194 	return ept;
1195 }
1196 
1197 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1198 {
1199 	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1200 	struct device_node *np = rpdev->dev.of_node;
1201 	struct qcom_glink *glink = channel->glink;
1202 	struct glink_core_rx_intent *intent;
1203 	const struct property *prop = NULL;
1204 	__be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1205 	int num_intents;
1206 	int num_groups = 1;
1207 	__be32 *val = defaults;
1208 	int size;
1209 
1210 	if (glink->intentless || !completion_done(&channel->open_ack))
1211 		return 0;
1212 
1213 	prop = of_find_property(np, "qcom,intents", NULL);
1214 	if (prop) {
1215 		val = prop->value;
1216 		num_groups = prop->length / sizeof(u32) / 2;
1217 	}
1218 
1219 	/* Channel is now open, advertise base set of intents */
1220 	while (num_groups--) {
1221 		size = be32_to_cpup(val++);
1222 		num_intents = be32_to_cpup(val++);
1223 		while (num_intents--) {
1224 			intent = qcom_glink_alloc_intent(glink, channel, size,
1225 							 true);
1226 			if (!intent)
1227 				break;
1228 
1229 			qcom_glink_advertise_intent(glink, channel, intent);
1230 		}
1231 	}
1232 	return 0;
1233 }
1234 
1235 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1236 {
1237 	struct glink_channel *channel = to_glink_channel(ept);
1238 	struct qcom_glink *glink = channel->glink;
1239 	unsigned long flags;
1240 
1241 	spin_lock_irqsave(&channel->recv_lock, flags);
1242 	channel->ept.cb = NULL;
1243 	spin_unlock_irqrestore(&channel->recv_lock, flags);
1244 
1245 	/* Decouple the potential rpdev from the channel */
1246 	channel->rpdev = NULL;
1247 
1248 	qcom_glink_send_close_req(glink, channel);
1249 }
1250 
1251 static int qcom_glink_request_intent(struct qcom_glink *glink,
1252 				     struct glink_channel *channel,
1253 				     size_t size)
1254 {
1255 	struct {
1256 		u16 id;
1257 		u16 cid;
1258 		u32 size;
1259 	} __packed cmd;
1260 
1261 	int ret;
1262 
1263 	mutex_lock(&channel->intent_req_lock);
1264 
1265 	reinit_completion(&channel->intent_req_comp);
1266 
1267 	cmd.id = RPM_CMD_RX_INTENT_REQ;
1268 	cmd.cid = channel->lcid;
1269 	cmd.size = size;
1270 
1271 	ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1272 	if (ret)
1273 		goto unlock;
1274 
1275 	ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1276 	if (!ret) {
1277 		dev_err(glink->dev, "intent request timed out\n");
1278 		ret = -ETIMEDOUT;
1279 	} else {
1280 		ret = channel->intent_req_result ? 0 : -ECANCELED;
1281 	}
1282 
1283 unlock:
1284 	mutex_unlock(&channel->intent_req_lock);
1285 	return ret;
1286 }
1287 
1288 static int __qcom_glink_send(struct glink_channel *channel,
1289 			     void *data, int len, bool wait)
1290 {
1291 	struct qcom_glink *glink = channel->glink;
1292 	struct glink_core_rx_intent *intent = NULL;
1293 	struct glink_core_rx_intent *tmp;
1294 	int iid = 0;
1295 	struct {
1296 		struct glink_msg msg;
1297 		__le32 chunk_size;
1298 		__le32 left_size;
1299 	} __packed req;
1300 	int ret;
1301 	unsigned long flags;
1302 	int chunk_size = len;
1303 	int left_size = 0;
1304 
1305 	if (!glink->intentless) {
1306 		while (!intent) {
1307 			spin_lock_irqsave(&channel->intent_lock, flags);
1308 			idr_for_each_entry(&channel->riids, tmp, iid) {
1309 				if (tmp->size >= len && !tmp->in_use) {
1310 					if (!intent)
1311 						intent = tmp;
1312 					else if (intent->size > tmp->size)
1313 						intent = tmp;
1314 					if (intent->size == len)
1315 						break;
1316 				}
1317 			}
1318 			if (intent)
1319 				intent->in_use = true;
1320 			spin_unlock_irqrestore(&channel->intent_lock, flags);
1321 
1322 			/* We found an available intent */
1323 			if (intent)
1324 				break;
1325 
1326 			if (!wait)
1327 				return -EBUSY;
1328 
1329 			ret = qcom_glink_request_intent(glink, channel, len);
1330 			if (ret < 0)
1331 				return ret;
1332 		}
1333 
1334 		iid = intent->id;
1335 	}
1336 
1337 	if (wait && chunk_size > SZ_8K) {
1338 		chunk_size = SZ_8K;
1339 		left_size = len - chunk_size;
1340 	}
1341 	req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1342 	req.msg.param1 = cpu_to_le16(channel->lcid);
1343 	req.msg.param2 = cpu_to_le32(iid);
1344 	req.chunk_size = cpu_to_le32(chunk_size);
1345 	req.left_size = cpu_to_le32(left_size);
1346 
1347 	ret = qcom_glink_tx(glink, &req, sizeof(req), data, chunk_size, wait);
1348 
1349 	/* Mark intent available if we failed */
1350 	if (ret && intent) {
1351 		intent->in_use = false;
1352 		return ret;
1353 	}
1354 
1355 	while (left_size > 0) {
1356 		data = (void *)((char *)data + chunk_size);
1357 		chunk_size = left_size;
1358 		if (chunk_size > SZ_8K)
1359 			chunk_size = SZ_8K;
1360 		left_size -= chunk_size;
1361 
1362 		req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA_CONT);
1363 		req.msg.param1 = cpu_to_le16(channel->lcid);
1364 		req.msg.param2 = cpu_to_le32(iid);
1365 		req.chunk_size = cpu_to_le32(chunk_size);
1366 		req.left_size = cpu_to_le32(left_size);
1367 
1368 		ret = qcom_glink_tx(glink, &req, sizeof(req), data,
1369 				    chunk_size, wait);
1370 
1371 		/* Mark intent available if we failed */
1372 		if (ret && intent) {
1373 			intent->in_use = false;
1374 			break;
1375 		}
1376 	}
1377 	return ret;
1378 }
1379 
1380 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1381 {
1382 	struct glink_channel *channel = to_glink_channel(ept);
1383 
1384 	return __qcom_glink_send(channel, data, len, true);
1385 }
1386 
1387 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1388 {
1389 	struct glink_channel *channel = to_glink_channel(ept);
1390 
1391 	return __qcom_glink_send(channel, data, len, false);
1392 }
1393 
1394 static int qcom_glink_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1395 {
1396 	struct glink_channel *channel = to_glink_channel(ept);
1397 
1398 	return __qcom_glink_send(channel, data, len, true);
1399 }
1400 
1401 static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1402 {
1403 	struct glink_channel *channel = to_glink_channel(ept);
1404 
1405 	return __qcom_glink_send(channel, data, len, false);
1406 }
1407 
1408 /*
1409  * Finds the device_node for the glink child interested in this channel.
1410  */
1411 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1412 						    const char *channel)
1413 {
1414 	struct device_node *child;
1415 	const char *name;
1416 	const char *key;
1417 	int ret;
1418 
1419 	for_each_available_child_of_node(node, child) {
1420 		key = "qcom,glink-channels";
1421 		ret = of_property_read_string(child, key, &name);
1422 		if (ret)
1423 			continue;
1424 
1425 		if (strcmp(name, channel) == 0)
1426 			return child;
1427 	}
1428 
1429 	return NULL;
1430 }
1431 
1432 static const struct rpmsg_device_ops glink_device_ops = {
1433 	.create_ept = qcom_glink_create_ept,
1434 	.announce_create = qcom_glink_announce_create,
1435 };
1436 
1437 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1438 	.destroy_ept = qcom_glink_destroy_ept,
1439 	.send = qcom_glink_send,
1440 	.sendto = qcom_glink_sendto,
1441 	.trysend = qcom_glink_trysend,
1442 	.trysendto = qcom_glink_trysendto,
1443 };
1444 
1445 static void qcom_glink_rpdev_release(struct device *dev)
1446 {
1447 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1448 
1449 	kfree(rpdev);
1450 }
1451 
1452 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1453 			      char *name)
1454 {
1455 	struct glink_channel *channel;
1456 	struct rpmsg_device *rpdev;
1457 	bool create_device = false;
1458 	struct device_node *node;
1459 	int lcid;
1460 	int ret;
1461 	unsigned long flags;
1462 
1463 	spin_lock_irqsave(&glink->idr_lock, flags);
1464 	idr_for_each_entry(&glink->lcids, channel, lcid) {
1465 		if (!strcmp(channel->name, name))
1466 			break;
1467 	}
1468 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1469 
1470 	if (!channel) {
1471 		channel = qcom_glink_alloc_channel(glink, name);
1472 		if (IS_ERR(channel))
1473 			return PTR_ERR(channel);
1474 
1475 		/* The opening dance was initiated by the remote */
1476 		create_device = true;
1477 	}
1478 
1479 	spin_lock_irqsave(&glink->idr_lock, flags);
1480 	ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1481 	if (ret < 0) {
1482 		dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1483 		spin_unlock_irqrestore(&glink->idr_lock, flags);
1484 		goto free_channel;
1485 	}
1486 	channel->rcid = ret;
1487 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1488 
1489 	complete_all(&channel->open_req);
1490 
1491 	if (create_device) {
1492 		rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1493 		if (!rpdev) {
1494 			ret = -ENOMEM;
1495 			goto rcid_remove;
1496 		}
1497 
1498 		rpdev->ept = &channel->ept;
1499 		strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1500 		rpdev->src = RPMSG_ADDR_ANY;
1501 		rpdev->dst = RPMSG_ADDR_ANY;
1502 		rpdev->ops = &glink_device_ops;
1503 
1504 		node = qcom_glink_match_channel(glink->dev->of_node, name);
1505 		rpdev->dev.of_node = node;
1506 		rpdev->dev.parent = glink->dev;
1507 		rpdev->dev.release = qcom_glink_rpdev_release;
1508 
1509 		ret = rpmsg_register_device(rpdev);
1510 		if (ret)
1511 			goto rcid_remove;
1512 
1513 		channel->rpdev = rpdev;
1514 	}
1515 
1516 	return 0;
1517 
1518 rcid_remove:
1519 	spin_lock_irqsave(&glink->idr_lock, flags);
1520 	idr_remove(&glink->rcids, channel->rcid);
1521 	channel->rcid = 0;
1522 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1523 free_channel:
1524 	/* Release the reference, iff we took it */
1525 	if (create_device)
1526 		kref_put(&channel->refcount, qcom_glink_channel_release);
1527 
1528 	return ret;
1529 }
1530 
1531 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1532 {
1533 	struct rpmsg_channel_info chinfo;
1534 	struct glink_channel *channel;
1535 	unsigned long flags;
1536 
1537 	spin_lock_irqsave(&glink->idr_lock, flags);
1538 	channel = idr_find(&glink->rcids, rcid);
1539 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1540 	if (WARN(!channel, "close request on unknown channel\n"))
1541 		return;
1542 
1543 	/* cancel pending rx_done work */
1544 	cancel_work_sync(&channel->intent_work);
1545 
1546 	if (channel->rpdev) {
1547 		strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1548 		chinfo.src = RPMSG_ADDR_ANY;
1549 		chinfo.dst = RPMSG_ADDR_ANY;
1550 
1551 		rpmsg_unregister_device(glink->dev, &chinfo);
1552 	}
1553 	channel->rpdev = NULL;
1554 
1555 	qcom_glink_send_close_ack(glink, channel->rcid);
1556 
1557 	spin_lock_irqsave(&glink->idr_lock, flags);
1558 	idr_remove(&glink->rcids, channel->rcid);
1559 	channel->rcid = 0;
1560 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1561 
1562 	kref_put(&channel->refcount, qcom_glink_channel_release);
1563 }
1564 
1565 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1566 {
1567 	struct rpmsg_channel_info chinfo;
1568 	struct glink_channel *channel;
1569 	unsigned long flags;
1570 
1571 	/* To wakeup any blocking writers */
1572 	wake_up_all(&glink->tx_avail_notify);
1573 
1574 	spin_lock_irqsave(&glink->idr_lock, flags);
1575 	channel = idr_find(&glink->lcids, lcid);
1576 	if (WARN(!channel, "close ack on unknown channel\n")) {
1577 		spin_unlock_irqrestore(&glink->idr_lock, flags);
1578 		return;
1579 	}
1580 
1581 	idr_remove(&glink->lcids, channel->lcid);
1582 	channel->lcid = 0;
1583 	spin_unlock_irqrestore(&glink->idr_lock, flags);
1584 
1585 	/* Decouple the potential rpdev from the channel */
1586 	if (channel->rpdev) {
1587 		strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1588 		chinfo.src = RPMSG_ADDR_ANY;
1589 		chinfo.dst = RPMSG_ADDR_ANY;
1590 
1591 		rpmsg_unregister_device(glink->dev, &chinfo);
1592 	}
1593 	channel->rpdev = NULL;
1594 
1595 	kref_put(&channel->refcount, qcom_glink_channel_release);
1596 }
1597 
1598 static void qcom_glink_work(struct work_struct *work)
1599 {
1600 	struct qcom_glink *glink = container_of(work, struct qcom_glink,
1601 						rx_work);
1602 	struct glink_defer_cmd *dcmd;
1603 	struct glink_msg *msg;
1604 	unsigned long flags;
1605 	unsigned int param1;
1606 	unsigned int param2;
1607 	unsigned int cmd;
1608 
1609 	for (;;) {
1610 		spin_lock_irqsave(&glink->rx_lock, flags);
1611 		if (list_empty(&glink->rx_queue)) {
1612 			spin_unlock_irqrestore(&glink->rx_lock, flags);
1613 			break;
1614 		}
1615 		dcmd = list_first_entry(&glink->rx_queue,
1616 					struct glink_defer_cmd, node);
1617 		list_del(&dcmd->node);
1618 		spin_unlock_irqrestore(&glink->rx_lock, flags);
1619 
1620 		msg = &dcmd->msg;
1621 		cmd = le16_to_cpu(msg->cmd);
1622 		param1 = le16_to_cpu(msg->param1);
1623 		param2 = le32_to_cpu(msg->param2);
1624 
1625 		switch (cmd) {
1626 		case RPM_CMD_VERSION:
1627 			qcom_glink_receive_version(glink, param1, param2);
1628 			break;
1629 		case RPM_CMD_VERSION_ACK:
1630 			qcom_glink_receive_version_ack(glink, param1, param2);
1631 			break;
1632 		case RPM_CMD_OPEN:
1633 			qcom_glink_rx_open(glink, param1, msg->data);
1634 			break;
1635 		case RPM_CMD_CLOSE:
1636 			qcom_glink_rx_close(glink, param1);
1637 			break;
1638 		case RPM_CMD_CLOSE_ACK:
1639 			qcom_glink_rx_close_ack(glink, param1);
1640 			break;
1641 		case RPM_CMD_RX_INTENT_REQ:
1642 			qcom_glink_handle_intent_req(glink, param1, param2);
1643 			break;
1644 		default:
1645 			WARN(1, "Unknown defer object %d\n", cmd);
1646 			break;
1647 		}
1648 
1649 		kfree(dcmd);
1650 	}
1651 }
1652 
1653 static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1654 {
1655 	struct glink_defer_cmd *dcmd;
1656 	struct glink_defer_cmd *tmp;
1657 
1658 	/* cancel any pending deferred rx_work */
1659 	cancel_work_sync(&glink->rx_work);
1660 
1661 	list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1662 		kfree(dcmd);
1663 }
1664 
1665 static ssize_t rpmsg_name_show(struct device *dev,
1666 			       struct device_attribute *attr, char *buf)
1667 {
1668 	int ret = 0;
1669 	const char *name;
1670 
1671 	ret = of_property_read_string(dev->of_node, "label", &name);
1672 	if (ret < 0)
1673 		name = dev->of_node->name;
1674 
1675 	return sysfs_emit(buf, "%s\n", name);
1676 }
1677 static DEVICE_ATTR_RO(rpmsg_name);
1678 
1679 static struct attribute *qcom_glink_attrs[] = {
1680 	&dev_attr_rpmsg_name.attr,
1681 	NULL
1682 };
1683 ATTRIBUTE_GROUPS(qcom_glink);
1684 
1685 static void qcom_glink_device_release(struct device *dev)
1686 {
1687 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1688 	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1689 
1690 	/* Release qcom_glink_alloc_channel() reference */
1691 	kref_put(&channel->refcount, qcom_glink_channel_release);
1692 	kfree(rpdev);
1693 }
1694 
1695 static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1696 {
1697 	struct rpmsg_device *rpdev;
1698 	struct glink_channel *channel;
1699 
1700 	rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1701 	if (!rpdev)
1702 		return -ENOMEM;
1703 
1704 	channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1705 	if (IS_ERR(channel)) {
1706 		kfree(rpdev);
1707 		return PTR_ERR(channel);
1708 	}
1709 	channel->rpdev = rpdev;
1710 
1711 	rpdev->ept = &channel->ept;
1712 	rpdev->ops = &glink_device_ops;
1713 	rpdev->dev.parent = glink->dev;
1714 	rpdev->dev.release = qcom_glink_device_release;
1715 
1716 	return rpmsg_ctrldev_register_device(rpdev);
1717 }
1718 
1719 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1720 					   unsigned long features,
1721 					   struct qcom_glink_pipe *rx,
1722 					   struct qcom_glink_pipe *tx,
1723 					   bool intentless)
1724 {
1725 	int irq;
1726 	int ret;
1727 	struct qcom_glink *glink;
1728 
1729 	glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1730 	if (!glink)
1731 		return ERR_PTR(-ENOMEM);
1732 
1733 	glink->dev = dev;
1734 	glink->tx_pipe = tx;
1735 	glink->rx_pipe = rx;
1736 
1737 	glink->features = features;
1738 	glink->intentless = intentless;
1739 
1740 	spin_lock_init(&glink->tx_lock);
1741 	spin_lock_init(&glink->rx_lock);
1742 	INIT_LIST_HEAD(&glink->rx_queue);
1743 	INIT_WORK(&glink->rx_work, qcom_glink_work);
1744 	init_waitqueue_head(&glink->tx_avail_notify);
1745 
1746 	spin_lock_init(&glink->idr_lock);
1747 	idr_init(&glink->lcids);
1748 	idr_init(&glink->rcids);
1749 
1750 	glink->dev->groups = qcom_glink_groups;
1751 
1752 	ret = device_add_groups(dev, qcom_glink_groups);
1753 	if (ret)
1754 		dev_err(dev, "failed to add groups\n");
1755 
1756 	glink->mbox_client.dev = dev;
1757 	glink->mbox_client.knows_txdone = true;
1758 	glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1759 	if (IS_ERR(glink->mbox_chan)) {
1760 		if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1761 			dev_err(dev, "failed to acquire IPC channel\n");
1762 		return ERR_CAST(glink->mbox_chan);
1763 	}
1764 
1765 	irq = of_irq_get(dev->of_node, 0);
1766 	ret = devm_request_irq(dev, irq,
1767 			       qcom_glink_native_intr,
1768 			       IRQF_NO_SUSPEND | IRQF_SHARED,
1769 			       "glink-native", glink);
1770 	if (ret) {
1771 		dev_err(dev, "failed to request IRQ\n");
1772 		return ERR_PTR(ret);
1773 	}
1774 
1775 	glink->irq = irq;
1776 
1777 	ret = qcom_glink_send_version(glink);
1778 	if (ret)
1779 		return ERR_PTR(ret);
1780 
1781 	ret = qcom_glink_create_chrdev(glink);
1782 	if (ret)
1783 		dev_err(glink->dev, "failed to register chrdev\n");
1784 
1785 	return glink;
1786 }
1787 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1788 
1789 static int qcom_glink_remove_device(struct device *dev, void *data)
1790 {
1791 	device_unregister(dev);
1792 
1793 	return 0;
1794 }
1795 
1796 void qcom_glink_native_remove(struct qcom_glink *glink)
1797 {
1798 	struct glink_channel *channel;
1799 	int cid;
1800 	int ret;
1801 
1802 	disable_irq(glink->irq);
1803 	qcom_glink_cancel_rx_work(glink);
1804 
1805 	ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1806 	if (ret)
1807 		dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1808 
1809 	/* Release any defunct local channels, waiting for close-ack */
1810 	idr_for_each_entry(&glink->lcids, channel, cid)
1811 		kref_put(&channel->refcount, qcom_glink_channel_release);
1812 
1813 	/* Release any defunct local channels, waiting for close-req */
1814 	idr_for_each_entry(&glink->rcids, channel, cid)
1815 		kref_put(&channel->refcount, qcom_glink_channel_release);
1816 
1817 	idr_destroy(&glink->lcids);
1818 	idr_destroy(&glink->rcids);
1819 	mbox_free_channel(glink->mbox_chan);
1820 }
1821 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1822 
1823 void qcom_glink_native_unregister(struct qcom_glink *glink)
1824 {
1825 	device_unregister(glink->dev);
1826 }
1827 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1828 
1829 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1830 MODULE_LICENSE("GPL v2");
1831