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
32struct 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 */
48struct 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 */
67struct 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 */
96struct qcom_glink {
97	struct device *dev;
98
99	const char *name;
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};
122
123enum {
124	GLINK_STATE_CLOSED,
125	GLINK_STATE_OPENING,
126	GLINK_STATE_OPEN,
127	GLINK_STATE_CLOSING,
128};
129
130/**
131 * struct glink_channel - internal representation of a channel
132 * @rpdev:	rpdev reference, only used for primary endpoints
133 * @ept:	rpmsg endpoint this channel is associated with
134 * @glink:	qcom_glink context handle
135 * @refcount:	refcount for the channel object
136 * @recv_lock:	guard for @ept.cb
137 * @name:	unique channel name/identifier
138 * @lcid:	channel id, in local space
139 * @rcid:	channel id, in remote space
140 * @intent_lock: lock for protection of @liids, @riids
141 * @liids:	idr of all local intents
142 * @riids:	idr of all remote intents
143 * @intent_work: worker responsible for transmitting rx_done packets
144 * @done_intents: list of intents that needs to be announced rx_done
145 * @buf:	receive buffer, for gathering fragments
146 * @buf_offset:	write offset in @buf
147 * @buf_size:	size of current @buf
148 * @open_ack:	completed once remote has acked the open-request
149 * @open_req:	completed once open-request has been received
150 * @intent_req_lock: Synchronises multiple intent requests
151 * @intent_req_result: Result of intent request
152 * @intent_req_comp: Completion for intent_req signalling
153 */
154struct glink_channel {
155	struct rpmsg_endpoint ept;
156
157	struct rpmsg_device *rpdev;
158	struct qcom_glink *glink;
159
160	struct kref refcount;
161
162	spinlock_t recv_lock;
163
164	char *name;
165	unsigned int lcid;
166	unsigned int rcid;
167
168	spinlock_t intent_lock;
169	struct idr liids;
170	struct idr riids;
171	struct work_struct intent_work;
172	struct list_head done_intents;
173
174	struct glink_core_rx_intent *buf;
175	int buf_offset;
176	int buf_size;
177
178	struct completion open_ack;
179	struct completion open_req;
180
181	struct mutex intent_req_lock;
182	bool intent_req_result;
183	struct completion intent_req_comp;
184};
185
186#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
187
188static const struct rpmsg_endpoint_ops glink_endpoint_ops;
189
190#define RPM_CMD_VERSION			0
191#define RPM_CMD_VERSION_ACK		1
192#define RPM_CMD_OPEN			2
193#define RPM_CMD_CLOSE			3
194#define RPM_CMD_OPEN_ACK		4
195#define RPM_CMD_INTENT			5
196#define RPM_CMD_RX_DONE			6
197#define RPM_CMD_RX_INTENT_REQ		7
198#define RPM_CMD_RX_INTENT_REQ_ACK	8
199#define RPM_CMD_TX_DATA			9
200#define RPM_CMD_CLOSE_ACK		11
201#define RPM_CMD_TX_DATA_CONT		12
202#define RPM_CMD_READ_NOTIF		13
203#define RPM_CMD_RX_DONE_W_REUSE		14
204
205#define GLINK_FEATURE_INTENTLESS	BIT(1)
206
207static void qcom_glink_rx_done_work(struct work_struct *work);
208
209static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
210						      const char *name)
211{
212	struct glink_channel *channel;
213
214	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
215	if (!channel)
216		return ERR_PTR(-ENOMEM);
217
218	/* Setup glink internal glink_channel data */
219	spin_lock_init(&channel->recv_lock);
220	spin_lock_init(&channel->intent_lock);
221	mutex_init(&channel->intent_req_lock);
222
223	channel->glink = glink;
224	channel->name = kstrdup(name, GFP_KERNEL);
225	if (!channel->name) {
226		kfree(channel);
227		return ERR_PTR(-ENOMEM);
228	}
229
230	init_completion(&channel->open_req);
231	init_completion(&channel->open_ack);
232	init_completion(&channel->intent_req_comp);
233
234	INIT_LIST_HEAD(&channel->done_intents);
235	INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
236
237	idr_init(&channel->liids);
238	idr_init(&channel->riids);
239	kref_init(&channel->refcount);
240
241	return channel;
242}
243
244static void qcom_glink_channel_release(struct kref *ref)
245{
246	struct glink_channel *channel = container_of(ref, struct glink_channel,
247						     refcount);
248	struct glink_core_rx_intent *intent;
249	struct glink_core_rx_intent *tmp;
250	unsigned long flags;
251	int iid;
252
253	/* cancel pending rx_done work */
254	cancel_work_sync(&channel->intent_work);
255
256	spin_lock_irqsave(&channel->intent_lock, flags);
257	/* Free all non-reuse intents pending rx_done work */
258	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
259		if (!intent->reuse) {
260			kfree(intent->data);
261			kfree(intent);
262		}
263	}
264
265	idr_for_each_entry(&channel->liids, tmp, iid) {
266		kfree(tmp->data);
267		kfree(tmp);
268	}
269	idr_destroy(&channel->liids);
270
271	idr_for_each_entry(&channel->riids, tmp, iid)
272		kfree(tmp);
273	idr_destroy(&channel->riids);
274	spin_unlock_irqrestore(&channel->intent_lock, flags);
275
276	kfree(channel->name);
277	kfree(channel);
278}
279
280static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
281{
282	return glink->rx_pipe->avail(glink->rx_pipe);
283}
284
285static void qcom_glink_rx_peak(struct qcom_glink *glink,
286			       void *data, unsigned int offset, size_t count)
287{
288	glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
289}
290
291static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
292{
293	glink->rx_pipe->advance(glink->rx_pipe, count);
294}
295
296static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
297{
298	return glink->tx_pipe->avail(glink->tx_pipe);
299}
300
301static void qcom_glink_tx_write(struct qcom_glink *glink,
302				const void *hdr, size_t hlen,
303				const void *data, size_t dlen)
304{
305	glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
306}
307
308static int qcom_glink_tx(struct qcom_glink *glink,
309			 const void *hdr, size_t hlen,
310			 const void *data, size_t dlen, bool wait)
311{
312	unsigned int tlen = hlen + dlen;
313	unsigned long flags;
314	int ret = 0;
315
316	/* Reject packets that are too big */
317	if (tlen >= glink->tx_pipe->length)
318		return -EINVAL;
319
320	spin_lock_irqsave(&glink->tx_lock, flags);
321
322	while (qcom_glink_tx_avail(glink) < tlen) {
323		if (!wait) {
324			ret = -EAGAIN;
325			goto out;
326		}
327
328		/* Wait without holding the tx_lock */
329		spin_unlock_irqrestore(&glink->tx_lock, flags);
330
331		usleep_range(10000, 15000);
332
333		spin_lock_irqsave(&glink->tx_lock, flags);
334	}
335
336	qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
337
338	mbox_send_message(glink->mbox_chan, NULL);
339	mbox_client_txdone(glink->mbox_chan, 0);
340
341out:
342	spin_unlock_irqrestore(&glink->tx_lock, flags);
343
344	return ret;
345}
346
347static int qcom_glink_send_version(struct qcom_glink *glink)
348{
349	struct glink_msg msg;
350
351	msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
352	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
353	msg.param2 = cpu_to_le32(glink->features);
354
355	return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
356}
357
358static void qcom_glink_send_version_ack(struct qcom_glink *glink)
359{
360	struct glink_msg msg;
361
362	msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
363	msg.param1 = cpu_to_le16(GLINK_VERSION_1);
364	msg.param2 = cpu_to_le32(glink->features);
365
366	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
367}
368
369static void qcom_glink_send_open_ack(struct qcom_glink *glink,
370				     struct glink_channel *channel)
371{
372	struct glink_msg msg;
373
374	msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
375	msg.param1 = cpu_to_le16(channel->rcid);
376	msg.param2 = cpu_to_le32(0);
377
378	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
379}
380
381static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
382					     unsigned int cid, bool granted)
383{
384	struct glink_channel *channel;
385	unsigned long flags;
386
387	spin_lock_irqsave(&glink->idr_lock, flags);
388	channel = idr_find(&glink->rcids, cid);
389	spin_unlock_irqrestore(&glink->idr_lock, flags);
390	if (!channel) {
391		dev_err(glink->dev, "unable to find channel\n");
392		return;
393	}
394
395	channel->intent_req_result = granted;
396	complete(&channel->intent_req_comp);
397}
398
399/**
400 * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
401 * @glink: Ptr to the glink edge
402 * @channel: Ptr to the channel that the open req is sent
403 *
404 * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
405 * Will return with refcount held, regardless of outcome.
406 *
407 * Returns 0 on success, negative errno otherwise.
408 */
409static int qcom_glink_send_open_req(struct qcom_glink *glink,
410				    struct glink_channel *channel)
411{
412	struct {
413		struct glink_msg msg;
414		u8 name[GLINK_NAME_SIZE];
415	} __packed req;
416	int name_len = strlen(channel->name) + 1;
417	int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
418	int ret;
419	unsigned long flags;
420
421	kref_get(&channel->refcount);
422
423	spin_lock_irqsave(&glink->idr_lock, flags);
424	ret = idr_alloc_cyclic(&glink->lcids, channel,
425			       RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
426			       GFP_ATOMIC);
427	spin_unlock_irqrestore(&glink->idr_lock, flags);
428	if (ret < 0)
429		return ret;
430
431	channel->lcid = ret;
432
433	req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
434	req.msg.param1 = cpu_to_le16(channel->lcid);
435	req.msg.param2 = cpu_to_le32(name_len);
436	strcpy(req.name, channel->name);
437
438	ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
439	if (ret)
440		goto remove_idr;
441
442	return 0;
443
444remove_idr:
445	spin_lock_irqsave(&glink->idr_lock, flags);
446	idr_remove(&glink->lcids, channel->lcid);
447	channel->lcid = 0;
448	spin_unlock_irqrestore(&glink->idr_lock, flags);
449
450	return ret;
451}
452
453static void qcom_glink_send_close_req(struct qcom_glink *glink,
454				      struct glink_channel *channel)
455{
456	struct glink_msg req;
457
458	req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
459	req.param1 = cpu_to_le16(channel->lcid);
460	req.param2 = 0;
461
462	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
463}
464
465static void qcom_glink_send_close_ack(struct qcom_glink *glink,
466				      unsigned int rcid)
467{
468	struct glink_msg req;
469
470	req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
471	req.param1 = cpu_to_le16(rcid);
472	req.param2 = 0;
473
474	qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
475}
476
477static void qcom_glink_rx_done_work(struct work_struct *work)
478{
479	struct glink_channel *channel = container_of(work, struct glink_channel,
480						     intent_work);
481	struct qcom_glink *glink = channel->glink;
482	struct glink_core_rx_intent *intent, *tmp;
483	struct {
484		u16 id;
485		u16 lcid;
486		u32 liid;
487	} __packed cmd;
488
489	unsigned int cid = channel->lcid;
490	unsigned int iid;
491	bool reuse;
492	unsigned long flags;
493
494	spin_lock_irqsave(&channel->intent_lock, flags);
495	list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
496		list_del(&intent->node);
497		spin_unlock_irqrestore(&channel->intent_lock, flags);
498		iid = intent->id;
499		reuse = intent->reuse;
500
501		cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
502		cmd.lcid = cid;
503		cmd.liid = iid;
504
505		qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
506		if (!reuse) {
507			kfree(intent->data);
508			kfree(intent);
509		}
510		spin_lock_irqsave(&channel->intent_lock, flags);
511	}
512	spin_unlock_irqrestore(&channel->intent_lock, flags);
513}
514
515static void qcom_glink_rx_done(struct qcom_glink *glink,
516			       struct glink_channel *channel,
517			       struct glink_core_rx_intent *intent)
518{
519	/* We don't send RX_DONE to intentless systems */
520	if (glink->intentless) {
521		kfree(intent->data);
522		kfree(intent);
523		return;
524	}
525
526	/* Take it off the tree of receive intents */
527	if (!intent->reuse) {
528		spin_lock(&channel->intent_lock);
529		idr_remove(&channel->liids, intent->id);
530		spin_unlock(&channel->intent_lock);
531	}
532
533	/* Schedule the sending of a rx_done indication */
534	spin_lock(&channel->intent_lock);
535	list_add_tail(&intent->node, &channel->done_intents);
536	spin_unlock(&channel->intent_lock);
537
538	schedule_work(&channel->intent_work);
539}
540
541/**
542 * qcom_glink_receive_version() - receive version/features from remote system
543 *
544 * @glink:	pointer to transport interface
545 * @version:	remote version
546 * @features:	remote features
547 *
548 * This function is called in response to a remote-initiated version/feature
549 * negotiation sequence.
550 */
551static void qcom_glink_receive_version(struct qcom_glink *glink,
552				       u32 version,
553				       u32 features)
554{
555	switch (version) {
556	case 0:
557		break;
558	case GLINK_VERSION_1:
559		glink->features &= features;
560		fallthrough;
561	default:
562		qcom_glink_send_version_ack(glink);
563		break;
564	}
565}
566
567/**
568 * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
569 *
570 * @glink:	pointer to transport interface
571 * @version:	remote version response
572 * @features:	remote features response
573 *
574 * This function is called in response to a local-initiated version/feature
575 * negotiation sequence and is the counter-offer from the remote side based
576 * upon the initial version and feature set requested.
577 */
578static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
579					   u32 version,
580					   u32 features)
581{
582	switch (version) {
583	case 0:
584		/* Version negotiation failed */
585		break;
586	case GLINK_VERSION_1:
587		if (features == glink->features)
588			break;
589
590		glink->features &= features;
591		fallthrough;
592	default:
593		qcom_glink_send_version(glink);
594		break;
595	}
596}
597
598/**
599 * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
600 * 	wire format and transmit
601 * @glink:	The transport to transmit on.
602 * @channel:	The glink channel
603 * @granted:	The request response to encode.
604 *
605 * Return: 0 on success or standard Linux error code.
606 */
607static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
608					  struct glink_channel *channel,
609					  bool granted)
610{
611	struct glink_msg msg;
612
613	msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
614	msg.param1 = cpu_to_le16(channel->lcid);
615	msg.param2 = cpu_to_le32(granted);
616
617	qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
618
619	return 0;
620}
621
622/**
623 * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
624 *			   transmit
625 * @glink:	The transport to transmit on.
626 * @channel:	The local channel
627 * @intent:	The intent to pass on to remote.
628 *
629 * Return: 0 on success or standard Linux error code.
630 */
631static int qcom_glink_advertise_intent(struct qcom_glink *glink,
632				       struct glink_channel *channel,
633				       struct glink_core_rx_intent *intent)
634{
635	struct command {
636		__le16 id;
637		__le16 lcid;
638		__le32 count;
639		__le32 size;
640		__le32 liid;
641	} __packed;
642	struct command cmd;
643
644	cmd.id = cpu_to_le16(RPM_CMD_INTENT);
645	cmd.lcid = cpu_to_le16(channel->lcid);
646	cmd.count = cpu_to_le32(1);
647	cmd.size = cpu_to_le32(intent->size);
648	cmd.liid = cpu_to_le32(intent->id);
649
650	qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
651
652	return 0;
653}
654
655static struct glink_core_rx_intent *
656qcom_glink_alloc_intent(struct qcom_glink *glink,
657			struct glink_channel *channel,
658			size_t size,
659			bool reuseable)
660{
661	struct glink_core_rx_intent *intent;
662	int ret;
663	unsigned long flags;
664
665	intent = kzalloc(sizeof(*intent), GFP_KERNEL);
666	if (!intent)
667		return NULL;
668
669	intent->data = kzalloc(size, GFP_KERNEL);
670	if (!intent->data)
671		goto free_intent;
672
673	spin_lock_irqsave(&channel->intent_lock, flags);
674	ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
675	if (ret < 0) {
676		spin_unlock_irqrestore(&channel->intent_lock, flags);
677		goto free_data;
678	}
679	spin_unlock_irqrestore(&channel->intent_lock, flags);
680
681	intent->id = ret;
682	intent->size = size;
683	intent->reuse = reuseable;
684
685	return intent;
686
687free_data:
688	kfree(intent->data);
689free_intent:
690	kfree(intent);
691	return NULL;
692}
693
694static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
695				      u32 cid, uint32_t iid,
696				      bool reuse)
697{
698	struct glink_core_rx_intent *intent;
699	struct glink_channel *channel;
700	unsigned long flags;
701
702	spin_lock_irqsave(&glink->idr_lock, flags);
703	channel = idr_find(&glink->rcids, cid);
704	spin_unlock_irqrestore(&glink->idr_lock, flags);
705	if (!channel) {
706		dev_err(glink->dev, "invalid channel id received\n");
707		return;
708	}
709
710	spin_lock_irqsave(&channel->intent_lock, flags);
711	intent = idr_find(&channel->riids, iid);
712
713	if (!intent) {
714		spin_unlock_irqrestore(&channel->intent_lock, flags);
715		dev_err(glink->dev, "invalid intent id received\n");
716		return;
717	}
718
719	intent->in_use = false;
720
721	if (!reuse) {
722		idr_remove(&channel->riids, intent->id);
723		kfree(intent);
724	}
725	spin_unlock_irqrestore(&channel->intent_lock, flags);
726}
727
728/**
729 * qcom_glink_handle_intent_req() - Receive a request for rx_intent
730 *					    from remote side
731 * @glink:      Pointer to the transport interface
732 * @cid:	Remote channel ID
733 * @size:	size of the intent
734 *
735 * The function searches for the local channel to which the request for
736 * rx_intent has arrived and allocates and notifies the remote back
737 */
738static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
739					 u32 cid, size_t size)
740{
741	struct glink_core_rx_intent *intent;
742	struct glink_channel *channel;
743	unsigned long flags;
744
745	spin_lock_irqsave(&glink->idr_lock, flags);
746	channel = idr_find(&glink->rcids, cid);
747	spin_unlock_irqrestore(&glink->idr_lock, flags);
748
749	if (!channel) {
750		pr_err("%s channel not found for cid %d\n", __func__, cid);
751		return;
752	}
753
754	intent = qcom_glink_alloc_intent(glink, channel, size, false);
755	if (intent)
756		qcom_glink_advertise_intent(glink, channel, intent);
757
758	qcom_glink_send_intent_req_ack(glink, channel, !!intent);
759}
760
761static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
762{
763	struct glink_defer_cmd *dcmd;
764
765	extra = ALIGN(extra, 8);
766
767	if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
768		dev_dbg(glink->dev, "Insufficient data in rx fifo");
769		return -ENXIO;
770	}
771
772	dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
773	if (!dcmd)
774		return -ENOMEM;
775
776	INIT_LIST_HEAD(&dcmd->node);
777
778	qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
779
780	spin_lock(&glink->rx_lock);
781	list_add_tail(&dcmd->node, &glink->rx_queue);
782	spin_unlock(&glink->rx_lock);
783
784	schedule_work(&glink->rx_work);
785	qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
786
787	return 0;
788}
789
790static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
791{
792	struct glink_core_rx_intent *intent;
793	struct glink_channel *channel;
794	struct {
795		struct glink_msg msg;
796		__le32 chunk_size;
797		__le32 left_size;
798	} __packed hdr;
799	unsigned int chunk_size;
800	unsigned int left_size;
801	unsigned int rcid;
802	unsigned int liid;
803	int ret = 0;
804	unsigned long flags;
805
806	if (avail < sizeof(hdr)) {
807		dev_dbg(glink->dev, "Not enough data in fifo\n");
808		return -EAGAIN;
809	}
810
811	qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
812	chunk_size = le32_to_cpu(hdr.chunk_size);
813	left_size = le32_to_cpu(hdr.left_size);
814
815	if (avail < sizeof(hdr) + chunk_size) {
816		dev_dbg(glink->dev, "Payload not yet in fifo\n");
817		return -EAGAIN;
818	}
819
820	rcid = le16_to_cpu(hdr.msg.param1);
821	spin_lock_irqsave(&glink->idr_lock, flags);
822	channel = idr_find(&glink->rcids, rcid);
823	spin_unlock_irqrestore(&glink->idr_lock, flags);
824	if (!channel) {
825		dev_dbg(glink->dev, "Data on non-existing channel\n");
826
827		/* Drop the message */
828		goto advance_rx;
829	}
830
831	if (glink->intentless) {
832		/* Might have an ongoing, fragmented, message to append */
833		if (!channel->buf) {
834			intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
835			if (!intent)
836				return -ENOMEM;
837
838			intent->data = kmalloc(chunk_size + left_size,
839					       GFP_ATOMIC);
840			if (!intent->data) {
841				kfree(intent);
842				return -ENOMEM;
843			}
844
845			intent->id = 0xbabababa;
846			intent->size = chunk_size + left_size;
847			intent->offset = 0;
848
849			channel->buf = intent;
850		} else {
851			intent = channel->buf;
852		}
853	} else {
854		liid = le32_to_cpu(hdr.msg.param2);
855
856		spin_lock_irqsave(&channel->intent_lock, flags);
857		intent = idr_find(&channel->liids, liid);
858		spin_unlock_irqrestore(&channel->intent_lock, flags);
859
860		if (!intent) {
861			dev_err(glink->dev,
862				"no intent found for channel %s intent %d",
863				channel->name, liid);
864			ret = -ENOENT;
865			goto advance_rx;
866		}
867	}
868
869	if (intent->size - intent->offset < chunk_size) {
870		dev_err(glink->dev, "Insufficient space in intent\n");
871
872		/* The packet header lied, drop payload */
873		goto advance_rx;
874	}
875
876	qcom_glink_rx_peak(glink, intent->data + intent->offset,
877			   sizeof(hdr), chunk_size);
878	intent->offset += chunk_size;
879
880	/* Handle message when no fragments remain to be received */
881	if (!left_size) {
882		spin_lock(&channel->recv_lock);
883		if (channel->ept.cb) {
884			channel->ept.cb(channel->ept.rpdev,
885					intent->data,
886					intent->offset,
887					channel->ept.priv,
888					RPMSG_ADDR_ANY);
889		}
890		spin_unlock(&channel->recv_lock);
891
892		intent->offset = 0;
893		channel->buf = NULL;
894
895		qcom_glink_rx_done(glink, channel, intent);
896	}
897
898advance_rx:
899	qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
900
901	return ret;
902}
903
904static void qcom_glink_handle_intent(struct qcom_glink *glink,
905				     unsigned int cid,
906				     unsigned int count,
907				     size_t avail)
908{
909	struct glink_core_rx_intent *intent;
910	struct glink_channel *channel;
911	struct intent_pair {
912		__le32 size;
913		__le32 iid;
914	};
915
916	struct {
917		struct glink_msg msg;
918		struct intent_pair intents[];
919	} __packed * msg;
920
921	const size_t msglen = struct_size(msg, intents, count);
922	int ret;
923	int i;
924	unsigned long flags;
925
926	if (avail < msglen) {
927		dev_dbg(glink->dev, "Not enough data in fifo\n");
928		return;
929	}
930
931	spin_lock_irqsave(&glink->idr_lock, flags);
932	channel = idr_find(&glink->rcids, cid);
933	spin_unlock_irqrestore(&glink->idr_lock, flags);
934	if (!channel) {
935		dev_err(glink->dev, "intents for non-existing channel\n");
936		qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
937		return;
938	}
939
940	msg = kmalloc(msglen, GFP_ATOMIC);
941	if (!msg)
942		return;
943
944	qcom_glink_rx_peak(glink, msg, 0, msglen);
945
946	for (i = 0; i < count; ++i) {
947		intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
948		if (!intent)
949			break;
950
951		intent->id = le32_to_cpu(msg->intents[i].iid);
952		intent->size = le32_to_cpu(msg->intents[i].size);
953
954		spin_lock_irqsave(&channel->intent_lock, flags);
955		ret = idr_alloc(&channel->riids, intent,
956				intent->id, intent->id + 1, GFP_ATOMIC);
957		spin_unlock_irqrestore(&channel->intent_lock, flags);
958
959		if (ret < 0)
960			dev_err(glink->dev, "failed to store remote intent\n");
961	}
962
963	kfree(msg);
964	qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
965}
966
967static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
968{
969	struct glink_channel *channel;
970
971	spin_lock(&glink->idr_lock);
972	channel = idr_find(&glink->lcids, lcid);
973	spin_unlock(&glink->idr_lock);
974	if (!channel) {
975		dev_err(glink->dev, "Invalid open ack packet\n");
976		return -EINVAL;
977	}
978
979	complete_all(&channel->open_ack);
980
981	return 0;
982}
983
984static irqreturn_t qcom_glink_native_intr(int irq, void *data)
985{
986	struct qcom_glink *glink = data;
987	struct glink_msg msg;
988	unsigned int param1;
989	unsigned int param2;
990	unsigned int avail;
991	unsigned int cmd;
992	int ret = 0;
993
994	for (;;) {
995		avail = qcom_glink_rx_avail(glink);
996		if (avail < sizeof(msg))
997			break;
998
999		qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
1000
1001		cmd = le16_to_cpu(msg.cmd);
1002		param1 = le16_to_cpu(msg.param1);
1003		param2 = le32_to_cpu(msg.param2);
1004
1005		switch (cmd) {
1006		case RPM_CMD_VERSION:
1007		case RPM_CMD_VERSION_ACK:
1008		case RPM_CMD_CLOSE:
1009		case RPM_CMD_CLOSE_ACK:
1010		case RPM_CMD_RX_INTENT_REQ:
1011			ret = qcom_glink_rx_defer(glink, 0);
1012			break;
1013		case RPM_CMD_OPEN_ACK:
1014			ret = qcom_glink_rx_open_ack(glink, param1);
1015			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1016			break;
1017		case RPM_CMD_OPEN:
1018			ret = qcom_glink_rx_defer(glink, param2);
1019			break;
1020		case RPM_CMD_TX_DATA:
1021		case RPM_CMD_TX_DATA_CONT:
1022			ret = qcom_glink_rx_data(glink, avail);
1023			break;
1024		case RPM_CMD_READ_NOTIF:
1025			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1026
1027			mbox_send_message(glink->mbox_chan, NULL);
1028			mbox_client_txdone(glink->mbox_chan, 0);
1029			break;
1030		case RPM_CMD_INTENT:
1031			qcom_glink_handle_intent(glink, param1, param2, avail);
1032			break;
1033		case RPM_CMD_RX_DONE:
1034			qcom_glink_handle_rx_done(glink, param1, param2, false);
1035			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1036			break;
1037		case RPM_CMD_RX_DONE_W_REUSE:
1038			qcom_glink_handle_rx_done(glink, param1, param2, true);
1039			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1040			break;
1041		case RPM_CMD_RX_INTENT_REQ_ACK:
1042			qcom_glink_handle_intent_req_ack(glink, param1, param2);
1043			qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1044			break;
1045		default:
1046			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1047			ret = -EINVAL;
1048			break;
1049		}
1050
1051		if (ret)
1052			break;
1053	}
1054
1055	return IRQ_HANDLED;
1056}
1057
1058/* Locally initiated rpmsg_create_ept */
1059static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1060						     const char *name)
1061{
1062	struct glink_channel *channel;
1063	int ret;
1064	unsigned long flags;
1065
1066	channel = qcom_glink_alloc_channel(glink, name);
1067	if (IS_ERR(channel))
1068		return ERR_CAST(channel);
1069
1070	ret = qcom_glink_send_open_req(glink, channel);
1071	if (ret)
1072		goto release_channel;
1073
1074	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1075	if (!ret)
1076		goto err_timeout;
1077
1078	ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1079	if (!ret)
1080		goto err_timeout;
1081
1082	qcom_glink_send_open_ack(glink, channel);
1083
1084	return channel;
1085
1086err_timeout:
1087	/* qcom_glink_send_open_req() did register the channel in lcids*/
1088	spin_lock_irqsave(&glink->idr_lock, flags);
1089	idr_remove(&glink->lcids, channel->lcid);
1090	spin_unlock_irqrestore(&glink->idr_lock, flags);
1091
1092release_channel:
1093	/* Release qcom_glink_send_open_req() reference */
1094	kref_put(&channel->refcount, qcom_glink_channel_release);
1095	/* Release qcom_glink_alloc_channel() reference */
1096	kref_put(&channel->refcount, qcom_glink_channel_release);
1097
1098	return ERR_PTR(-ETIMEDOUT);
1099}
1100
1101/* Remote initiated rpmsg_create_ept */
1102static int qcom_glink_create_remote(struct qcom_glink *glink,
1103				    struct glink_channel *channel)
1104{
1105	int ret;
1106
1107	qcom_glink_send_open_ack(glink, channel);
1108
1109	ret = qcom_glink_send_open_req(glink, channel);
1110	if (ret)
1111		goto close_link;
1112
1113	ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1114	if (!ret) {
1115		ret = -ETIMEDOUT;
1116		goto close_link;
1117	}
1118
1119	return 0;
1120
1121close_link:
1122	/*
1123	 * Send a close request to "undo" our open-ack. The close-ack will
1124	 * release qcom_glink_send_open_req() reference and the last reference
1125	 * will be relesed after receiving remote_close or transport unregister
1126	 * by calling qcom_glink_native_remove().
1127	 */
1128	qcom_glink_send_close_req(glink, channel);
1129
1130	return ret;
1131}
1132
1133static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1134						    rpmsg_rx_cb_t cb,
1135						    void *priv,
1136						    struct rpmsg_channel_info
1137									chinfo)
1138{
1139	struct glink_channel *parent = to_glink_channel(rpdev->ept);
1140	struct glink_channel *channel;
1141	struct qcom_glink *glink = parent->glink;
1142	struct rpmsg_endpoint *ept;
1143	const char *name = chinfo.name;
1144	int cid;
1145	int ret;
1146	unsigned long flags;
1147
1148	spin_lock_irqsave(&glink->idr_lock, flags);
1149	idr_for_each_entry(&glink->rcids, channel, cid) {
1150		if (!strcmp(channel->name, name))
1151			break;
1152	}
1153	spin_unlock_irqrestore(&glink->idr_lock, flags);
1154
1155	if (!channel) {
1156		channel = qcom_glink_create_local(glink, name);
1157		if (IS_ERR(channel))
1158			return NULL;
1159	} else {
1160		ret = qcom_glink_create_remote(glink, channel);
1161		if (ret)
1162			return NULL;
1163	}
1164
1165	ept = &channel->ept;
1166	ept->rpdev = rpdev;
1167	ept->cb = cb;
1168	ept->priv = priv;
1169	ept->ops = &glink_endpoint_ops;
1170
1171	return ept;
1172}
1173
1174static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1175{
1176	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1177	struct device_node *np = rpdev->dev.of_node;
1178	struct qcom_glink *glink = channel->glink;
1179	struct glink_core_rx_intent *intent;
1180	const struct property *prop = NULL;
1181	__be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1182	int num_intents;
1183	int num_groups = 1;
1184	__be32 *val = defaults;
1185	int size;
1186
1187	if (glink->intentless || !completion_done(&channel->open_ack))
1188		return 0;
1189
1190	prop = of_find_property(np, "qcom,intents", NULL);
1191	if (prop) {
1192		val = prop->value;
1193		num_groups = prop->length / sizeof(u32) / 2;
1194	}
1195
1196	/* Channel is now open, advertise base set of intents */
1197	while (num_groups--) {
1198		size = be32_to_cpup(val++);
1199		num_intents = be32_to_cpup(val++);
1200		while (num_intents--) {
1201			intent = qcom_glink_alloc_intent(glink, channel, size,
1202							 true);
1203			if (!intent)
1204				break;
1205
1206			qcom_glink_advertise_intent(glink, channel, intent);
1207		}
1208	}
1209	return 0;
1210}
1211
1212static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1213{
1214	struct glink_channel *channel = to_glink_channel(ept);
1215	struct qcom_glink *glink = channel->glink;
1216	unsigned long flags;
1217
1218	spin_lock_irqsave(&channel->recv_lock, flags);
1219	channel->ept.cb = NULL;
1220	spin_unlock_irqrestore(&channel->recv_lock, flags);
1221
1222	/* Decouple the potential rpdev from the channel */
1223	channel->rpdev = NULL;
1224
1225	qcom_glink_send_close_req(glink, channel);
1226}
1227
1228static int qcom_glink_request_intent(struct qcom_glink *glink,
1229				     struct glink_channel *channel,
1230				     size_t size)
1231{
1232	struct {
1233		u16 id;
1234		u16 cid;
1235		u32 size;
1236	} __packed cmd;
1237
1238	int ret;
1239
1240	mutex_lock(&channel->intent_req_lock);
1241
1242	reinit_completion(&channel->intent_req_comp);
1243
1244	cmd.id = RPM_CMD_RX_INTENT_REQ;
1245	cmd.cid = channel->lcid;
1246	cmd.size = size;
1247
1248	ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1249	if (ret)
1250		goto unlock;
1251
1252	ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1253	if (!ret) {
1254		dev_err(glink->dev, "intent request timed out\n");
1255		ret = -ETIMEDOUT;
1256	} else {
1257		ret = channel->intent_req_result ? 0 : -ECANCELED;
1258	}
1259
1260unlock:
1261	mutex_unlock(&channel->intent_req_lock);
1262	return ret;
1263}
1264
1265static int __qcom_glink_send(struct glink_channel *channel,
1266			     void *data, int len, bool wait)
1267{
1268	struct qcom_glink *glink = channel->glink;
1269	struct glink_core_rx_intent *intent = NULL;
1270	struct glink_core_rx_intent *tmp;
1271	int iid = 0;
1272	struct {
1273		struct glink_msg msg;
1274		__le32 chunk_size;
1275		__le32 left_size;
1276	} __packed req;
1277	int ret;
1278	unsigned long flags;
1279
1280	if (!glink->intentless) {
1281		while (!intent) {
1282			spin_lock_irqsave(&channel->intent_lock, flags);
1283			idr_for_each_entry(&channel->riids, tmp, iid) {
1284				if (tmp->size >= len && !tmp->in_use) {
1285					if (!intent)
1286						intent = tmp;
1287					else if (intent->size > tmp->size)
1288						intent = tmp;
1289					if (intent->size == len)
1290						break;
1291				}
1292			}
1293			if (intent)
1294				intent->in_use = true;
1295			spin_unlock_irqrestore(&channel->intent_lock, flags);
1296
1297			/* We found an available intent */
1298			if (intent)
1299				break;
1300
1301			if (!wait)
1302				return -EBUSY;
1303
1304			ret = qcom_glink_request_intent(glink, channel, len);
1305			if (ret < 0)
1306				return ret;
1307		}
1308
1309		iid = intent->id;
1310	}
1311
1312	req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1313	req.msg.param1 = cpu_to_le16(channel->lcid);
1314	req.msg.param2 = cpu_to_le32(iid);
1315	req.chunk_size = cpu_to_le32(len);
1316	req.left_size = cpu_to_le32(0);
1317
1318	ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1319
1320	/* Mark intent available if we failed */
1321	if (ret && intent)
1322		intent->in_use = false;
1323
1324	return ret;
1325}
1326
1327static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1328{
1329	struct glink_channel *channel = to_glink_channel(ept);
1330
1331	return __qcom_glink_send(channel, data, len, true);
1332}
1333
1334static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1335{
1336	struct glink_channel *channel = to_glink_channel(ept);
1337
1338	return __qcom_glink_send(channel, data, len, false);
1339}
1340
1341/*
1342 * Finds the device_node for the glink child interested in this channel.
1343 */
1344static struct device_node *qcom_glink_match_channel(struct device_node *node,
1345						    const char *channel)
1346{
1347	struct device_node *child;
1348	const char *name;
1349	const char *key;
1350	int ret;
1351
1352	for_each_available_child_of_node(node, child) {
1353		key = "qcom,glink-channels";
1354		ret = of_property_read_string(child, key, &name);
1355		if (ret)
1356			continue;
1357
1358		if (strcmp(name, channel) == 0)
1359			return child;
1360	}
1361
1362	return NULL;
1363}
1364
1365static const struct rpmsg_device_ops glink_device_ops = {
1366	.create_ept = qcom_glink_create_ept,
1367	.announce_create = qcom_glink_announce_create,
1368};
1369
1370static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1371	.destroy_ept = qcom_glink_destroy_ept,
1372	.send = qcom_glink_send,
1373	.trysend = qcom_glink_trysend,
1374};
1375
1376static void qcom_glink_rpdev_release(struct device *dev)
1377{
1378	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1379	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1380
1381	channel->rpdev = NULL;
1382	kfree(rpdev->driver_override);
1383	kfree(rpdev);
1384}
1385
1386static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1387			      char *name)
1388{
1389	struct glink_channel *channel;
1390	struct rpmsg_device *rpdev;
1391	bool create_device = false;
1392	struct device_node *node;
1393	int lcid;
1394	int ret;
1395	unsigned long flags;
1396
1397	spin_lock_irqsave(&glink->idr_lock, flags);
1398	idr_for_each_entry(&glink->lcids, channel, lcid) {
1399		if (!strcmp(channel->name, name))
1400			break;
1401	}
1402	spin_unlock_irqrestore(&glink->idr_lock, flags);
1403
1404	if (!channel) {
1405		channel = qcom_glink_alloc_channel(glink, name);
1406		if (IS_ERR(channel))
1407			return PTR_ERR(channel);
1408
1409		/* The opening dance was initiated by the remote */
1410		create_device = true;
1411	}
1412
1413	spin_lock_irqsave(&glink->idr_lock, flags);
1414	ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1415	if (ret < 0) {
1416		dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1417		spin_unlock_irqrestore(&glink->idr_lock, flags);
1418		goto free_channel;
1419	}
1420	channel->rcid = ret;
1421	spin_unlock_irqrestore(&glink->idr_lock, flags);
1422
1423	complete_all(&channel->open_req);
1424
1425	if (create_device) {
1426		rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1427		if (!rpdev) {
1428			ret = -ENOMEM;
1429			goto rcid_remove;
1430		}
1431
1432		rpdev->ept = &channel->ept;
1433		strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1434		rpdev->src = RPMSG_ADDR_ANY;
1435		rpdev->dst = RPMSG_ADDR_ANY;
1436		rpdev->ops = &glink_device_ops;
1437
1438		node = qcom_glink_match_channel(glink->dev->of_node, name);
1439		rpdev->dev.of_node = node;
1440		rpdev->dev.parent = glink->dev;
1441		rpdev->dev.release = qcom_glink_rpdev_release;
1442
1443		ret = rpmsg_register_device(rpdev);
1444		if (ret)
1445			goto rcid_remove;
1446
1447		channel->rpdev = rpdev;
1448	}
1449
1450	return 0;
1451
1452rcid_remove:
1453	spin_lock_irqsave(&glink->idr_lock, flags);
1454	idr_remove(&glink->rcids, channel->rcid);
1455	channel->rcid = 0;
1456	spin_unlock_irqrestore(&glink->idr_lock, flags);
1457free_channel:
1458	/* Release the reference, iff we took it */
1459	if (create_device)
1460		kref_put(&channel->refcount, qcom_glink_channel_release);
1461
1462	return ret;
1463}
1464
1465static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1466{
1467	struct rpmsg_channel_info chinfo;
1468	struct glink_channel *channel;
1469	unsigned long flags;
1470
1471	spin_lock_irqsave(&glink->idr_lock, flags);
1472	channel = idr_find(&glink->rcids, rcid);
1473	spin_unlock_irqrestore(&glink->idr_lock, flags);
1474	if (WARN(!channel, "close request on unknown channel\n"))
1475		return;
1476
1477	/* cancel pending rx_done work */
1478	cancel_work_sync(&channel->intent_work);
1479
1480	if (channel->rpdev) {
1481		strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1482		chinfo.src = RPMSG_ADDR_ANY;
1483		chinfo.dst = RPMSG_ADDR_ANY;
1484
1485		rpmsg_unregister_device(glink->dev, &chinfo);
1486	}
1487
1488	qcom_glink_send_close_ack(glink, channel->rcid);
1489
1490	spin_lock_irqsave(&glink->idr_lock, flags);
1491	idr_remove(&glink->rcids, channel->rcid);
1492	channel->rcid = 0;
1493	spin_unlock_irqrestore(&glink->idr_lock, flags);
1494
1495	kref_put(&channel->refcount, qcom_glink_channel_release);
1496}
1497
1498static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1499{
1500	struct glink_channel *channel;
1501	unsigned long flags;
1502
1503	spin_lock_irqsave(&glink->idr_lock, flags);
1504	channel = idr_find(&glink->lcids, lcid);
1505	if (WARN(!channel, "close ack on unknown channel\n")) {
1506		spin_unlock_irqrestore(&glink->idr_lock, flags);
1507		return;
1508	}
1509
1510	idr_remove(&glink->lcids, channel->lcid);
1511	channel->lcid = 0;
1512	spin_unlock_irqrestore(&glink->idr_lock, flags);
1513
1514	kref_put(&channel->refcount, qcom_glink_channel_release);
1515}
1516
1517static void qcom_glink_work(struct work_struct *work)
1518{
1519	struct qcom_glink *glink = container_of(work, struct qcom_glink,
1520						rx_work);
1521	struct glink_defer_cmd *dcmd;
1522	struct glink_msg *msg;
1523	unsigned long flags;
1524	unsigned int param1;
1525	unsigned int param2;
1526	unsigned int cmd;
1527
1528	for (;;) {
1529		spin_lock_irqsave(&glink->rx_lock, flags);
1530		if (list_empty(&glink->rx_queue)) {
1531			spin_unlock_irqrestore(&glink->rx_lock, flags);
1532			break;
1533		}
1534		dcmd = list_first_entry(&glink->rx_queue,
1535					struct glink_defer_cmd, node);
1536		list_del(&dcmd->node);
1537		spin_unlock_irqrestore(&glink->rx_lock, flags);
1538
1539		msg = &dcmd->msg;
1540		cmd = le16_to_cpu(msg->cmd);
1541		param1 = le16_to_cpu(msg->param1);
1542		param2 = le32_to_cpu(msg->param2);
1543
1544		switch (cmd) {
1545		case RPM_CMD_VERSION:
1546			qcom_glink_receive_version(glink, param1, param2);
1547			break;
1548		case RPM_CMD_VERSION_ACK:
1549			qcom_glink_receive_version_ack(glink, param1, param2);
1550			break;
1551		case RPM_CMD_OPEN:
1552			qcom_glink_rx_open(glink, param1, msg->data);
1553			break;
1554		case RPM_CMD_CLOSE:
1555			qcom_glink_rx_close(glink, param1);
1556			break;
1557		case RPM_CMD_CLOSE_ACK:
1558			qcom_glink_rx_close_ack(glink, param1);
1559			break;
1560		case RPM_CMD_RX_INTENT_REQ:
1561			qcom_glink_handle_intent_req(glink, param1, param2);
1562			break;
1563		default:
1564			WARN(1, "Unknown defer object %d\n", cmd);
1565			break;
1566		}
1567
1568		kfree(dcmd);
1569	}
1570}
1571
1572static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1573{
1574	struct glink_defer_cmd *dcmd;
1575	struct glink_defer_cmd *tmp;
1576
1577	/* cancel any pending deferred rx_work */
1578	cancel_work_sync(&glink->rx_work);
1579
1580	list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1581		kfree(dcmd);
1582}
1583
1584static ssize_t rpmsg_name_show(struct device *dev,
1585			       struct device_attribute *attr, char *buf)
1586{
1587	int ret = 0;
1588	const char *name;
1589
1590	ret = of_property_read_string(dev->of_node, "label", &name);
1591	if (ret < 0)
1592		name = dev->of_node->name;
1593
1594	return snprintf(buf, RPMSG_NAME_SIZE, "%s\n", name);
1595}
1596static DEVICE_ATTR_RO(rpmsg_name);
1597
1598static struct attribute *qcom_glink_attrs[] = {
1599	&dev_attr_rpmsg_name.attr,
1600	NULL
1601};
1602ATTRIBUTE_GROUPS(qcom_glink);
1603
1604static void qcom_glink_device_release(struct device *dev)
1605{
1606	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1607	struct glink_channel *channel = to_glink_channel(rpdev->ept);
1608
1609	/* Release qcom_glink_alloc_channel() reference */
1610	kref_put(&channel->refcount, qcom_glink_channel_release);
1611	kfree(rpdev->driver_override);
1612	kfree(rpdev);
1613}
1614
1615static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1616{
1617	struct rpmsg_device *rpdev;
1618	struct glink_channel *channel;
1619
1620	rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1621	if (!rpdev)
1622		return -ENOMEM;
1623
1624	channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1625	if (IS_ERR(channel)) {
1626		kfree(rpdev);
1627		return PTR_ERR(channel);
1628	}
1629	channel->rpdev = rpdev;
1630
1631	rpdev->ept = &channel->ept;
1632	rpdev->ops = &glink_device_ops;
1633	rpdev->dev.parent = glink->dev;
1634	rpdev->dev.release = qcom_glink_device_release;
1635
1636	return rpmsg_chrdev_register_device(rpdev);
1637}
1638
1639struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1640					   unsigned long features,
1641					   struct qcom_glink_pipe *rx,
1642					   struct qcom_glink_pipe *tx,
1643					   bool intentless)
1644{
1645	int irq;
1646	int ret;
1647	struct qcom_glink *glink;
1648
1649	glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1650	if (!glink)
1651		return ERR_PTR(-ENOMEM);
1652
1653	glink->dev = dev;
1654	glink->tx_pipe = tx;
1655	glink->rx_pipe = rx;
1656
1657	glink->features = features;
1658	glink->intentless = intentless;
1659
1660	spin_lock_init(&glink->tx_lock);
1661	spin_lock_init(&glink->rx_lock);
1662	INIT_LIST_HEAD(&glink->rx_queue);
1663	INIT_WORK(&glink->rx_work, qcom_glink_work);
1664
1665	spin_lock_init(&glink->idr_lock);
1666	idr_init(&glink->lcids);
1667	idr_init(&glink->rcids);
1668
1669	glink->dev->groups = qcom_glink_groups;
1670
1671	ret = device_add_groups(dev, qcom_glink_groups);
1672	if (ret)
1673		dev_err(dev, "failed to add groups\n");
1674
1675	ret = of_property_read_string(dev->of_node, "label", &glink->name);
1676	if (ret < 0)
1677		glink->name = dev->of_node->name;
1678
1679	glink->mbox_client.dev = dev;
1680	glink->mbox_client.knows_txdone = true;
1681	glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1682	if (IS_ERR(glink->mbox_chan)) {
1683		if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1684			dev_err(dev, "failed to acquire IPC channel\n");
1685		return ERR_CAST(glink->mbox_chan);
1686	}
1687
1688	irq = of_irq_get(dev->of_node, 0);
1689	ret = devm_request_irq(dev, irq,
1690			       qcom_glink_native_intr,
1691			       IRQF_NO_SUSPEND | IRQF_SHARED,
1692			       "glink-native", glink);
1693	if (ret) {
1694		dev_err(dev, "failed to request IRQ\n");
1695		return ERR_PTR(ret);
1696	}
1697
1698	glink->irq = irq;
1699
1700	ret = qcom_glink_send_version(glink);
1701	if (ret)
1702		return ERR_PTR(ret);
1703
1704	ret = qcom_glink_create_chrdev(glink);
1705	if (ret)
1706		dev_err(glink->dev, "failed to register chrdev\n");
1707
1708	return glink;
1709}
1710EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1711
1712static int qcom_glink_remove_device(struct device *dev, void *data)
1713{
1714	device_unregister(dev);
1715
1716	return 0;
1717}
1718
1719void qcom_glink_native_remove(struct qcom_glink *glink)
1720{
1721	struct glink_channel *channel;
1722	int cid;
1723	int ret;
1724
1725	disable_irq(glink->irq);
1726	qcom_glink_cancel_rx_work(glink);
1727
1728	ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1729	if (ret)
1730		dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1731
1732	/* Release any defunct local channels, waiting for close-ack */
1733	idr_for_each_entry(&glink->lcids, channel, cid)
1734		kref_put(&channel->refcount, qcom_glink_channel_release);
1735
1736	/* Release any defunct local channels, waiting for close-req */
1737	idr_for_each_entry(&glink->rcids, channel, cid)
1738		kref_put(&channel->refcount, qcom_glink_channel_release);
1739
1740	idr_destroy(&glink->lcids);
1741	idr_destroy(&glink->rcids);
1742	mbox_free_channel(glink->mbox_chan);
1743}
1744EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1745
1746void qcom_glink_native_unregister(struct qcom_glink *glink)
1747{
1748	device_unregister(glink->dev);
1749}
1750EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1751
1752MODULE_DESCRIPTION("Qualcomm GLINK driver");
1753MODULE_LICENSE("GPL v2");
1754