rpmsg: glink: The mbox client knows_txdone
[sfrench/cifs-2.6.git] / drivers / rpmsg / qcom_glink_native.c
1 /*
2  * Copyright (c) 2016-2017, Linaro Ltd
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 and
6  * only version 2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13
14 #include <linux/idr.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/list.h>
18 #include <linux/mfd/syscon.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_address.h>
22 #include <linux/of_irq.h>
23 #include <linux/platform_device.h>
24 #include <linux/regmap.h>
25 #include <linux/rpmsg.h>
26 #include <linux/sizes.h>
27 #include <linux/slab.h>
28 #include <linux/workqueue.h>
29 #include <linux/mailbox_client.h>
30
31 #include "rpmsg_internal.h"
32 #include "qcom_glink_native.h"
33
34 #define GLINK_NAME_SIZE         32
35 #define GLINK_VERSION_1         1
36
37 #define RPM_GLINK_CID_MIN       1
38 #define RPM_GLINK_CID_MAX       65536
39
40 struct glink_msg {
41         __le16 cmd;
42         __le16 param1;
43         __le32 param2;
44         u8 data[];
45 } __packed;
46
47 /**
48  * struct glink_defer_cmd - deferred incoming control message
49  * @node:       list node
50  * @msg:        message header
51  * data:        payload of the message
52  *
53  * Copy of a received control message, to be added to @rx_queue and processed
54  * by @rx_work of @qcom_glink.
55  */
56 struct glink_defer_cmd {
57         struct list_head node;
58
59         struct glink_msg msg;
60         u8 data[];
61 };
62
63 /**
64  * struct glink_core_rx_intent - RX intent
65  * RX intent
66  *
67  * data: pointer to the data (may be NULL for zero-copy)
68  * id: remote or local intent ID
69  * size: size of the original intent (do not modify)
70  * reuse: To mark if the intent can be reused after first use
71  * in_use: To mark if intent is already in use for the channel
72  * offset: next write offset (initially 0)
73  */
74 struct glink_core_rx_intent {
75         void *data;
76         u32 id;
77         size_t size;
78         bool reuse;
79         bool in_use;
80         u32 offset;
81
82         struct list_head node;
83 };
84
85 /**
86  * struct qcom_glink - driver context, relates to one remote subsystem
87  * @dev:        reference to the associated struct device
88  * @mbox_client: mailbox client
89  * @mbox_chan:  mailbox channel
90  * @rx_pipe:    pipe object for receive FIFO
91  * @tx_pipe:    pipe object for transmit FIFO
92  * @irq:        IRQ for signaling incoming events
93  * @rx_work:    worker for handling received control messages
94  * @rx_lock:    protects the @rx_queue
95  * @rx_queue:   queue of received control messages to be processed in @rx_work
96  * @tx_lock:    synchronizes operations on the tx fifo
97  * @idr_lock:   synchronizes @lcids and @rcids modifications
98  * @lcids:      idr of all channels with a known local channel id
99  * @rcids:      idr of all channels with a known remote channel id
100  */
101 struct qcom_glink {
102         struct device *dev;
103
104         struct mbox_client mbox_client;
105         struct mbox_chan *mbox_chan;
106
107         struct qcom_glink_pipe *rx_pipe;
108         struct qcom_glink_pipe *tx_pipe;
109
110         int irq;
111
112         struct work_struct rx_work;
113         spinlock_t rx_lock;
114         struct list_head rx_queue;
115
116         struct mutex tx_lock;
117
118         spinlock_t idr_lock;
119         struct idr lcids;
120         struct idr rcids;
121         unsigned long features;
122
123         bool intentless;
124 };
125
126 enum {
127         GLINK_STATE_CLOSED,
128         GLINK_STATE_OPENING,
129         GLINK_STATE_OPEN,
130         GLINK_STATE_CLOSING,
131 };
132
133 /**
134  * struct glink_channel - internal representation of a channel
135  * @rpdev:      rpdev reference, only used for primary endpoints
136  * @ept:        rpmsg endpoint this channel is associated with
137  * @glink:      qcom_glink context handle
138  * @refcount:   refcount for the channel object
139  * @recv_lock:  guard for @ept.cb
140  * @name:       unique channel name/identifier
141  * @lcid:       channel id, in local space
142  * @rcid:       channel id, in remote space
143  * @intent_lock: lock for protection of @liids, @riids
144  * @liids:      idr of all local intents
145  * @riids:      idr of all remote intents
146  * @intent_work: worker responsible for transmitting rx_done packets
147  * @done_intents: list of intents that needs to be announced rx_done
148  * @buf:        receive buffer, for gathering fragments
149  * @buf_offset: write offset in @buf
150  * @buf_size:   size of current @buf
151  * @open_ack:   completed once remote has acked the open-request
152  * @open_req:   completed once open-request has been received
153  * @intent_req_lock: Synchronises multiple intent requests
154  * @intent_req_result: Result of intent request
155  * @intent_req_comp: Completion for intent_req signalling
156  */
157 struct glink_channel {
158         struct rpmsg_endpoint ept;
159
160         struct rpmsg_device *rpdev;
161         struct qcom_glink *glink;
162
163         struct kref refcount;
164
165         spinlock_t recv_lock;
166
167         char *name;
168         unsigned int lcid;
169         unsigned int rcid;
170
171         spinlock_t intent_lock;
172         struct idr liids;
173         struct idr riids;
174         struct work_struct intent_work;
175         struct list_head done_intents;
176
177         struct glink_core_rx_intent *buf;
178         int buf_offset;
179         int buf_size;
180
181         struct completion open_ack;
182         struct completion open_req;
183
184         struct mutex intent_req_lock;
185         bool intent_req_result;
186         struct completion intent_req_comp;
187 };
188
189 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
190
191 static const struct rpmsg_endpoint_ops glink_endpoint_ops;
192
193 #define RPM_CMD_VERSION                 0
194 #define RPM_CMD_VERSION_ACK             1
195 #define RPM_CMD_OPEN                    2
196 #define RPM_CMD_CLOSE                   3
197 #define RPM_CMD_OPEN_ACK                4
198 #define RPM_CMD_INTENT                  5
199 #define RPM_CMD_RX_DONE                 6
200 #define RPM_CMD_RX_INTENT_REQ           7
201 #define RPM_CMD_RX_INTENT_REQ_ACK       8
202 #define RPM_CMD_TX_DATA                 9
203 #define RPM_CMD_CLOSE_ACK               11
204 #define RPM_CMD_TX_DATA_CONT            12
205 #define RPM_CMD_READ_NOTIF              13
206 #define RPM_CMD_RX_DONE_W_REUSE         14
207
208 #define GLINK_FEATURE_INTENTLESS        BIT(1)
209
210 static void qcom_glink_rx_done_work(struct work_struct *work);
211
212 static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
213                                                       const char *name)
214 {
215         struct glink_channel *channel;
216
217         channel = kzalloc(sizeof(*channel), GFP_KERNEL);
218         if (!channel)
219                 return ERR_PTR(-ENOMEM);
220
221         /* Setup glink internal glink_channel data */
222         spin_lock_init(&channel->recv_lock);
223         spin_lock_init(&channel->intent_lock);
224
225         channel->glink = glink;
226         channel->name = kstrdup(name, GFP_KERNEL);
227
228         init_completion(&channel->open_req);
229         init_completion(&channel->open_ack);
230         init_completion(&channel->intent_req_comp);
231
232         INIT_LIST_HEAD(&channel->done_intents);
233         INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
234
235         idr_init(&channel->liids);
236         idr_init(&channel->riids);
237         kref_init(&channel->refcount);
238
239         return channel;
240 }
241
242 static void qcom_glink_channel_release(struct kref *ref)
243 {
244         struct glink_channel *channel = container_of(ref, struct glink_channel,
245                                                      refcount);
246         unsigned long flags;
247
248         spin_lock_irqsave(&channel->intent_lock, flags);
249         idr_destroy(&channel->liids);
250         idr_destroy(&channel->riids);
251         spin_unlock_irqrestore(&channel->intent_lock, flags);
252
253         kfree(channel->name);
254         kfree(channel);
255 }
256
257 static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
258 {
259         return glink->rx_pipe->avail(glink->rx_pipe);
260 }
261
262 static void qcom_glink_rx_peak(struct qcom_glink *glink,
263                                void *data, unsigned int offset, size_t count)
264 {
265         glink->rx_pipe->peak(glink->rx_pipe, data, offset, count);
266 }
267
268 static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
269 {
270         glink->rx_pipe->advance(glink->rx_pipe, count);
271 }
272
273 static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
274 {
275         return glink->tx_pipe->avail(glink->tx_pipe);
276 }
277
278 static void qcom_glink_tx_write(struct qcom_glink *glink,
279                                 const void *hdr, size_t hlen,
280                                 const void *data, size_t dlen)
281 {
282         glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
283 }
284
285 static int qcom_glink_tx(struct qcom_glink *glink,
286                          const void *hdr, size_t hlen,
287                          const void *data, size_t dlen, bool wait)
288 {
289         unsigned int tlen = hlen + dlen;
290         int ret;
291
292         /* Reject packets that are too big */
293         if (tlen >= glink->tx_pipe->length)
294                 return -EINVAL;
295
296         ret = mutex_lock_interruptible(&glink->tx_lock);
297         if (ret)
298                 return ret;
299
300         while (qcom_glink_tx_avail(glink) < tlen) {
301                 if (!wait) {
302                         ret = -EAGAIN;
303                         goto out;
304                 }
305
306                 usleep_range(10000, 15000);
307         }
308
309         qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
310
311         mbox_send_message(glink->mbox_chan, NULL);
312         mbox_client_txdone(glink->mbox_chan, 0);
313
314 out:
315         mutex_unlock(&glink->tx_lock);
316
317         return ret;
318 }
319
320 static int qcom_glink_send_version(struct qcom_glink *glink)
321 {
322         struct glink_msg msg;
323
324         msg.cmd = cpu_to_le16(RPM_CMD_VERSION);
325         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
326         msg.param2 = cpu_to_le32(glink->features);
327
328         return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
329 }
330
331 static void qcom_glink_send_version_ack(struct qcom_glink *glink)
332 {
333         struct glink_msg msg;
334
335         msg.cmd = cpu_to_le16(RPM_CMD_VERSION_ACK);
336         msg.param1 = cpu_to_le16(GLINK_VERSION_1);
337         msg.param2 = cpu_to_le32(glink->features);
338
339         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
340 }
341
342 static void qcom_glink_send_open_ack(struct qcom_glink *glink,
343                                      struct glink_channel *channel)
344 {
345         struct glink_msg msg;
346
347         msg.cmd = cpu_to_le16(RPM_CMD_OPEN_ACK);
348         msg.param1 = cpu_to_le16(channel->rcid);
349         msg.param2 = cpu_to_le32(0);
350
351         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
352 }
353
354 static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
355                                              unsigned int cid, bool granted)
356 {
357         struct glink_channel *channel;
358         unsigned long flags;
359
360         spin_lock_irqsave(&glink->idr_lock, flags);
361         channel = idr_find(&glink->rcids, cid);
362         spin_unlock_irqrestore(&glink->idr_lock, flags);
363         if (!channel) {
364                 dev_err(glink->dev, "unable to find channel\n");
365                 return;
366         }
367
368         channel->intent_req_result = granted;
369         complete(&channel->intent_req_comp);
370 }
371
372 /**
373  * qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
374  * @glink: Ptr to the glink edge
375  * @channel: Ptr to the channel that the open req is sent
376  *
377  * Allocates a local channel id and sends a RPM_CMD_OPEN message to the remote.
378  * Will return with refcount held, regardless of outcome.
379  *
380  * Returns 0 on success, negative errno otherwise.
381  */
382 static int qcom_glink_send_open_req(struct qcom_glink *glink,
383                                     struct glink_channel *channel)
384 {
385         struct {
386                 struct glink_msg msg;
387                 u8 name[GLINK_NAME_SIZE];
388         } __packed req;
389         int name_len = strlen(channel->name) + 1;
390         int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
391         int ret;
392         unsigned long flags;
393
394         kref_get(&channel->refcount);
395
396         spin_lock_irqsave(&glink->idr_lock, flags);
397         ret = idr_alloc_cyclic(&glink->lcids, channel,
398                                RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
399                                GFP_ATOMIC);
400         spin_unlock_irqrestore(&glink->idr_lock, flags);
401         if (ret < 0)
402                 return ret;
403
404         channel->lcid = ret;
405
406         req.msg.cmd = cpu_to_le16(RPM_CMD_OPEN);
407         req.msg.param1 = cpu_to_le16(channel->lcid);
408         req.msg.param2 = cpu_to_le32(name_len);
409         strcpy(req.name, channel->name);
410
411         ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
412         if (ret)
413                 goto remove_idr;
414
415         return 0;
416
417 remove_idr:
418         spin_lock_irqsave(&glink->idr_lock, flags);
419         idr_remove(&glink->lcids, channel->lcid);
420         channel->lcid = 0;
421         spin_unlock_irqrestore(&glink->idr_lock, flags);
422
423         return ret;
424 }
425
426 static void qcom_glink_send_close_req(struct qcom_glink *glink,
427                                       struct glink_channel *channel)
428 {
429         struct glink_msg req;
430
431         req.cmd = cpu_to_le16(RPM_CMD_CLOSE);
432         req.param1 = cpu_to_le16(channel->lcid);
433         req.param2 = 0;
434
435         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
436 }
437
438 static void qcom_glink_send_close_ack(struct qcom_glink *glink,
439                                       unsigned int rcid)
440 {
441         struct glink_msg req;
442
443         req.cmd = cpu_to_le16(RPM_CMD_CLOSE_ACK);
444         req.param1 = cpu_to_le16(rcid);
445         req.param2 = 0;
446
447         qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
448 }
449
450 static void qcom_glink_rx_done_work(struct work_struct *work)
451 {
452         struct glink_channel *channel = container_of(work, struct glink_channel,
453                                                      intent_work);
454         struct qcom_glink *glink = channel->glink;
455         struct glink_core_rx_intent *intent, *tmp;
456         struct {
457                 u16 id;
458                 u16 lcid;
459                 u32 liid;
460         } __packed cmd;
461
462         unsigned int cid = channel->lcid;
463         unsigned int iid;
464         bool reuse;
465         unsigned long flags;
466
467         spin_lock_irqsave(&channel->intent_lock, flags);
468         list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
469                 list_del(&intent->node);
470                 spin_unlock_irqrestore(&channel->intent_lock, flags);
471                 iid = intent->id;
472                 reuse = intent->reuse;
473
474                 cmd.id = reuse ? RPM_CMD_RX_DONE_W_REUSE : RPM_CMD_RX_DONE;
475                 cmd.lcid = cid;
476                 cmd.liid = iid;
477
478                 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
479                 if (!reuse) {
480                         kfree(intent->data);
481                         kfree(intent);
482                 }
483                 spin_lock_irqsave(&channel->intent_lock, flags);
484         }
485         spin_unlock_irqrestore(&channel->intent_lock, flags);
486 }
487
488 static void qcom_glink_rx_done(struct qcom_glink *glink,
489                                struct glink_channel *channel,
490                                struct glink_core_rx_intent *intent)
491 {
492         /* We don't send RX_DONE to intentless systems */
493         if (glink->intentless) {
494                 kfree(intent->data);
495                 kfree(intent);
496                 return;
497         }
498
499         /* Take it off the tree of receive intents */
500         if (!intent->reuse) {
501                 spin_lock(&channel->intent_lock);
502                 idr_remove(&channel->liids, intent->id);
503                 spin_unlock(&channel->intent_lock);
504         }
505
506         /* Schedule the sending of a rx_done indication */
507         spin_lock(&channel->intent_lock);
508         list_add_tail(&intent->node, &channel->done_intents);
509         spin_unlock(&channel->intent_lock);
510
511         schedule_work(&channel->intent_work);
512 }
513
514 /**
515  * qcom_glink_receive_version() - receive version/features from remote system
516  *
517  * @glink:      pointer to transport interface
518  * @r_version:  remote version
519  * @r_features: remote features
520  *
521  * This function is called in response to a remote-initiated version/feature
522  * negotiation sequence.
523  */
524 static void qcom_glink_receive_version(struct qcom_glink *glink,
525                                        u32 version,
526                                        u32 features)
527 {
528         switch (version) {
529         case 0:
530                 break;
531         case GLINK_VERSION_1:
532                 glink->features &= features;
533                 /* FALLTHROUGH */
534         default:
535                 qcom_glink_send_version_ack(glink);
536                 break;
537         }
538 }
539
540 /**
541  * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
542  *
543  * @glink:      pointer to transport interface
544  * @r_version:  remote version response
545  * @r_features: remote features response
546  *
547  * This function is called in response to a local-initiated version/feature
548  * negotiation sequence and is the counter-offer from the remote side based
549  * upon the initial version and feature set requested.
550  */
551 static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
552                                            u32 version,
553                                            u32 features)
554 {
555         switch (version) {
556         case 0:
557                 /* Version negotiation failed */
558                 break;
559         case GLINK_VERSION_1:
560                 if (features == glink->features)
561                         break;
562
563                 glink->features &= features;
564                 /* FALLTHROUGH */
565         default:
566                 qcom_glink_send_version(glink);
567                 break;
568         }
569 }
570
571 /**
572  * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
573                                       wire format and transmit
574  * @glink:      The transport to transmit on.
575  * @channel:    The glink channel
576  * @granted:    The request response to encode.
577  *
578  * Return: 0 on success or standard Linux error code.
579  */
580 static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
581                                           struct glink_channel *channel,
582                                           bool granted)
583 {
584         struct glink_msg msg;
585
586         msg.cmd = cpu_to_le16(RPM_CMD_RX_INTENT_REQ_ACK);
587         msg.param1 = cpu_to_le16(channel->lcid);
588         msg.param2 = cpu_to_le32(granted);
589
590         qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
591
592         return 0;
593 }
594
595 /**
596  * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
597  *                         transmit
598  * @glink:      The transport to transmit on.
599  * @channel:    The local channel
600  * @size:       The intent to pass on to remote.
601  *
602  * Return: 0 on success or standard Linux error code.
603  */
604 static int qcom_glink_advertise_intent(struct qcom_glink *glink,
605                                        struct glink_channel *channel,
606                                        struct glink_core_rx_intent *intent)
607 {
608         struct command {
609                 u16 id;
610                 u16 lcid;
611                 u32 count;
612                 u32 size;
613                 u32 liid;
614         } __packed;
615         struct command cmd;
616
617         cmd.id = cpu_to_le16(RPM_CMD_INTENT);
618         cmd.lcid = cpu_to_le16(channel->lcid);
619         cmd.count = cpu_to_le32(1);
620         cmd.size = cpu_to_le32(intent->size);
621         cmd.liid = cpu_to_le32(intent->id);
622
623         qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
624
625         return 0;
626 }
627
628 static struct glink_core_rx_intent *
629 qcom_glink_alloc_intent(struct qcom_glink *glink,
630                         struct glink_channel *channel,
631                         size_t size,
632                         bool reuseable)
633 {
634         struct glink_core_rx_intent *intent;
635         int ret;
636         unsigned long flags;
637
638         intent = kzalloc(sizeof(*intent), GFP_KERNEL);
639         if (!intent)
640                 return NULL;
641
642         intent->data = kzalloc(size, GFP_KERNEL);
643         if (!intent->data)
644                 goto free_intent;
645
646         spin_lock_irqsave(&channel->intent_lock, flags);
647         ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
648         if (ret < 0) {
649                 spin_unlock_irqrestore(&channel->intent_lock, flags);
650                 goto free_data;
651         }
652         spin_unlock_irqrestore(&channel->intent_lock, flags);
653
654         intent->id = ret;
655         intent->size = size;
656         intent->reuse = reuseable;
657
658         return intent;
659
660 free_data:
661         kfree(intent->data);
662 free_intent:
663         kfree(intent);
664         return NULL;
665 }
666
667 static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
668                                       u32 cid, uint32_t iid,
669                                       bool reuse)
670 {
671         struct glink_core_rx_intent *intent;
672         struct glink_channel *channel;
673         unsigned long flags;
674
675         spin_lock_irqsave(&glink->idr_lock, flags);
676         channel = idr_find(&glink->rcids, cid);
677         spin_unlock_irqrestore(&glink->idr_lock, flags);
678         if (!channel) {
679                 dev_err(glink->dev, "invalid channel id received\n");
680                 return;
681         }
682
683         spin_lock_irqsave(&channel->intent_lock, flags);
684         intent = idr_find(&channel->riids, iid);
685
686         if (!intent) {
687                 spin_unlock_irqrestore(&channel->intent_lock, flags);
688                 dev_err(glink->dev, "invalid intent id received\n");
689                 return;
690         }
691
692         intent->in_use = false;
693
694         if (!reuse) {
695                 idr_remove(&channel->riids, intent->id);
696                 kfree(intent);
697         }
698         spin_unlock_irqrestore(&channel->intent_lock, flags);
699 }
700
701 /**
702  * qcom_glink_handle_intent_req() - Receive a request for rx_intent
703  *                                          from remote side
704  * if_ptr:      Pointer to the transport interface
705  * rcid:        Remote channel ID
706  * size:        size of the intent
707  *
708  * The function searches for the local channel to which the request for
709  * rx_intent has arrived and allocates and notifies the remote back
710  */
711 static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
712                                          u32 cid, size_t size)
713 {
714         struct glink_core_rx_intent *intent;
715         struct glink_channel *channel;
716         unsigned long flags;
717
718         spin_lock_irqsave(&glink->idr_lock, flags);
719         channel = idr_find(&glink->rcids, cid);
720         spin_unlock_irqrestore(&glink->idr_lock, flags);
721
722         if (!channel) {
723                 pr_err("%s channel not found for cid %d\n", __func__, cid);
724                 return;
725         }
726
727         intent = qcom_glink_alloc_intent(glink, channel, size, false);
728         if (intent)
729                 qcom_glink_advertise_intent(glink, channel, intent);
730
731         qcom_glink_send_intent_req_ack(glink, channel, !!intent);
732 }
733
734 static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
735 {
736         struct glink_defer_cmd *dcmd;
737
738         extra = ALIGN(extra, 8);
739
740         if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
741                 dev_dbg(glink->dev, "Insufficient data in rx fifo");
742                 return -ENXIO;
743         }
744
745         dcmd = kzalloc(sizeof(*dcmd) + extra, GFP_ATOMIC);
746         if (!dcmd)
747                 return -ENOMEM;
748
749         INIT_LIST_HEAD(&dcmd->node);
750
751         qcom_glink_rx_peak(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
752
753         spin_lock(&glink->rx_lock);
754         list_add_tail(&dcmd->node, &glink->rx_queue);
755         spin_unlock(&glink->rx_lock);
756
757         schedule_work(&glink->rx_work);
758         qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
759
760         return 0;
761 }
762
763 static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
764 {
765         struct glink_core_rx_intent *intent;
766         struct glink_channel *channel;
767         struct {
768                 struct glink_msg msg;
769                 __le32 chunk_size;
770                 __le32 left_size;
771         } __packed hdr;
772         unsigned int chunk_size;
773         unsigned int left_size;
774         unsigned int rcid;
775         unsigned int liid;
776         int ret = 0;
777         unsigned long flags;
778
779         if (avail < sizeof(hdr)) {
780                 dev_dbg(glink->dev, "Not enough data in fifo\n");
781                 return -EAGAIN;
782         }
783
784         qcom_glink_rx_peak(glink, &hdr, 0, sizeof(hdr));
785         chunk_size = le32_to_cpu(hdr.chunk_size);
786         left_size = le32_to_cpu(hdr.left_size);
787
788         if (avail < sizeof(hdr) + chunk_size) {
789                 dev_dbg(glink->dev, "Payload not yet in fifo\n");
790                 return -EAGAIN;
791         }
792
793         if (WARN(chunk_size % 4, "Incoming data must be word aligned\n"))
794                 return -EINVAL;
795
796         rcid = le16_to_cpu(hdr.msg.param1);
797         spin_lock_irqsave(&glink->idr_lock, flags);
798         channel = idr_find(&glink->rcids, rcid);
799         spin_unlock_irqrestore(&glink->idr_lock, flags);
800         if (!channel) {
801                 dev_dbg(glink->dev, "Data on non-existing channel\n");
802
803                 /* Drop the message */
804                 goto advance_rx;
805         }
806
807         if (glink->intentless) {
808                 /* Might have an ongoing, fragmented, message to append */
809                 if (!channel->buf) {
810                         intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
811                         if (!intent)
812                                 return -ENOMEM;
813
814                         intent->data = kmalloc(chunk_size + left_size,
815                                                GFP_ATOMIC);
816                         if (!intent->data) {
817                                 kfree(intent);
818                                 return -ENOMEM;
819                         }
820
821                         intent->id = 0xbabababa;
822                         intent->size = chunk_size + left_size;
823                         intent->offset = 0;
824
825                         channel->buf = intent;
826                 } else {
827                         intent = channel->buf;
828                 }
829         } else {
830                 liid = le32_to_cpu(hdr.msg.param2);
831
832                 spin_lock_irqsave(&channel->intent_lock, flags);
833                 intent = idr_find(&channel->liids, liid);
834                 spin_unlock_irqrestore(&channel->intent_lock, flags);
835
836                 if (!intent) {
837                         dev_err(glink->dev,
838                                 "no intent found for channel %s intent %d",
839                                 channel->name, liid);
840                         goto advance_rx;
841                 }
842         }
843
844         if (intent->size - intent->offset < chunk_size) {
845                 dev_err(glink->dev, "Insufficient space in intent\n");
846
847                 /* The packet header lied, drop payload */
848                 goto advance_rx;
849         }
850
851         qcom_glink_rx_peak(glink, intent->data + intent->offset,
852                            sizeof(hdr), chunk_size);
853         intent->offset += chunk_size;
854
855         /* Handle message when no fragments remain to be received */
856         if (!left_size) {
857                 spin_lock(&channel->recv_lock);
858                 if (channel->ept.cb) {
859                         channel->ept.cb(channel->ept.rpdev,
860                                         intent->data,
861                                         intent->offset,
862                                         channel->ept.priv,
863                                         RPMSG_ADDR_ANY);
864                 }
865                 spin_unlock(&channel->recv_lock);
866
867                 intent->offset = 0;
868                 channel->buf = NULL;
869
870                 qcom_glink_rx_done(glink, channel, intent);
871         }
872
873 advance_rx:
874         qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
875
876         return ret;
877 }
878
879 static void qcom_glink_handle_intent(struct qcom_glink *glink,
880                                      unsigned int cid,
881                                      unsigned int count,
882                                      size_t avail)
883 {
884         struct glink_core_rx_intent *intent;
885         struct glink_channel *channel;
886         struct intent_pair {
887                 __le32 size;
888                 __le32 iid;
889         };
890
891         struct {
892                 struct glink_msg msg;
893                 struct intent_pair intents[];
894         } __packed * msg;
895
896         const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
897         int ret;
898         int i;
899         unsigned long flags;
900
901         if (avail < msglen) {
902                 dev_dbg(glink->dev, "Not enough data in fifo\n");
903                 return;
904         }
905
906         spin_lock_irqsave(&glink->idr_lock, flags);
907         channel = idr_find(&glink->rcids, cid);
908         spin_unlock_irqrestore(&glink->idr_lock, flags);
909         if (!channel) {
910                 dev_err(glink->dev, "intents for non-existing channel\n");
911                 return;
912         }
913
914         msg = kmalloc(msglen, GFP_ATOMIC);
915         if (!msg)
916                 return;
917
918         qcom_glink_rx_peak(glink, msg, 0, msglen);
919
920         for (i = 0; i < count; ++i) {
921                 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
922                 if (!intent)
923                         break;
924
925                 intent->id = le32_to_cpu(msg->intents[i].iid);
926                 intent->size = le32_to_cpu(msg->intents[i].size);
927
928                 spin_lock_irqsave(&channel->intent_lock, flags);
929                 ret = idr_alloc(&channel->riids, intent,
930                                 intent->id, intent->id + 1, GFP_ATOMIC);
931                 spin_unlock_irqrestore(&channel->intent_lock, flags);
932
933                 if (ret < 0)
934                         dev_err(glink->dev, "failed to store remote intent\n");
935         }
936
937         kfree(msg);
938         qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
939 }
940
941 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
942 {
943         struct glink_channel *channel;
944
945         spin_lock(&glink->idr_lock);
946         channel = idr_find(&glink->lcids, lcid);
947         spin_unlock(&glink->idr_lock);
948         if (!channel) {
949                 dev_err(glink->dev, "Invalid open ack packet\n");
950                 return -EINVAL;
951         }
952
953         complete(&channel->open_ack);
954
955         return 0;
956 }
957
958 static irqreturn_t qcom_glink_native_intr(int irq, void *data)
959 {
960         struct qcom_glink *glink = data;
961         struct glink_msg msg;
962         unsigned int param1;
963         unsigned int param2;
964         unsigned int avail;
965         unsigned int cmd;
966         int ret = 0;
967
968         for (;;) {
969                 avail = qcom_glink_rx_avail(glink);
970                 if (avail < sizeof(msg))
971                         break;
972
973                 qcom_glink_rx_peak(glink, &msg, 0, sizeof(msg));
974
975                 cmd = le16_to_cpu(msg.cmd);
976                 param1 = le16_to_cpu(msg.param1);
977                 param2 = le32_to_cpu(msg.param2);
978
979                 switch (cmd) {
980                 case RPM_CMD_VERSION:
981                 case RPM_CMD_VERSION_ACK:
982                 case RPM_CMD_CLOSE:
983                 case RPM_CMD_CLOSE_ACK:
984                 case RPM_CMD_RX_INTENT_REQ:
985                         ret = qcom_glink_rx_defer(glink, 0);
986                         break;
987                 case RPM_CMD_OPEN_ACK:
988                         ret = qcom_glink_rx_open_ack(glink, param1);
989                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
990                         break;
991                 case RPM_CMD_OPEN:
992                         ret = qcom_glink_rx_defer(glink, param2);
993                         break;
994                 case RPM_CMD_TX_DATA:
995                 case RPM_CMD_TX_DATA_CONT:
996                         ret = qcom_glink_rx_data(glink, avail);
997                         break;
998                 case RPM_CMD_READ_NOTIF:
999                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1000
1001                         mbox_send_message(glink->mbox_chan, NULL);
1002                         mbox_client_txdone(glink->mbox_chan, 0);
1003                         break;
1004                 case RPM_CMD_INTENT:
1005                         qcom_glink_handle_intent(glink, param1, param2, avail);
1006                         break;
1007                 case RPM_CMD_RX_DONE:
1008                         qcom_glink_handle_rx_done(glink, param1, param2, false);
1009                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1010                         break;
1011                 case RPM_CMD_RX_DONE_W_REUSE:
1012                         qcom_glink_handle_rx_done(glink, param1, param2, true);
1013                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1014                         break;
1015                 case RPM_CMD_RX_INTENT_REQ_ACK:
1016                         qcom_glink_handle_intent_req_ack(glink, param1, param2);
1017                         qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1018                         break;
1019                 default:
1020                         dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1021                         ret = -EINVAL;
1022                         break;
1023                 }
1024
1025                 if (ret)
1026                         break;
1027         }
1028
1029         return IRQ_HANDLED;
1030 }
1031
1032 /* Locally initiated rpmsg_create_ept */
1033 static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1034                                                      const char *name)
1035 {
1036         struct glink_channel *channel;
1037         int ret;
1038         unsigned long flags;
1039
1040         channel = qcom_glink_alloc_channel(glink, name);
1041         if (IS_ERR(channel))
1042                 return ERR_CAST(channel);
1043
1044         ret = qcom_glink_send_open_req(glink, channel);
1045         if (ret)
1046                 goto release_channel;
1047
1048         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1049         if (!ret)
1050                 goto err_timeout;
1051
1052         ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1053         if (!ret)
1054                 goto err_timeout;
1055
1056         qcom_glink_send_open_ack(glink, channel);
1057
1058         return channel;
1059
1060 err_timeout:
1061         /* qcom_glink_send_open_req() did register the channel in lcids*/
1062         spin_lock_irqsave(&glink->idr_lock, flags);
1063         idr_remove(&glink->lcids, channel->lcid);
1064         spin_unlock_irqrestore(&glink->idr_lock, flags);
1065
1066 release_channel:
1067         /* Release qcom_glink_send_open_req() reference */
1068         kref_put(&channel->refcount, qcom_glink_channel_release);
1069         /* Release qcom_glink_alloc_channel() reference */
1070         kref_put(&channel->refcount, qcom_glink_channel_release);
1071
1072         return ERR_PTR(-ETIMEDOUT);
1073 }
1074
1075 /* Remote initiated rpmsg_create_ept */
1076 static int qcom_glink_create_remote(struct qcom_glink *glink,
1077                                     struct glink_channel *channel)
1078 {
1079         int ret;
1080
1081         qcom_glink_send_open_ack(glink, channel);
1082
1083         ret = qcom_glink_send_open_req(glink, channel);
1084         if (ret)
1085                 goto close_link;
1086
1087         ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1088         if (!ret) {
1089                 ret = -ETIMEDOUT;
1090                 goto close_link;
1091         }
1092
1093         return 0;
1094
1095 close_link:
1096         /*
1097          * Send a close request to "undo" our open-ack. The close-ack will
1098          * release the last reference.
1099          */
1100         qcom_glink_send_close_req(glink, channel);
1101
1102         /* Release qcom_glink_send_open_req() reference */
1103         kref_put(&channel->refcount, qcom_glink_channel_release);
1104
1105         return ret;
1106 }
1107
1108 static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1109                                                     rpmsg_rx_cb_t cb,
1110                                                     void *priv,
1111                                                     struct rpmsg_channel_info
1112                                                                         chinfo)
1113 {
1114         struct glink_channel *parent = to_glink_channel(rpdev->ept);
1115         struct glink_channel *channel;
1116         struct qcom_glink *glink = parent->glink;
1117         struct rpmsg_endpoint *ept;
1118         const char *name = chinfo.name;
1119         int cid;
1120         int ret;
1121         unsigned long flags;
1122
1123         spin_lock_irqsave(&glink->idr_lock, flags);
1124         idr_for_each_entry(&glink->rcids, channel, cid) {
1125                 if (!strcmp(channel->name, name))
1126                         break;
1127         }
1128         spin_unlock_irqrestore(&glink->idr_lock, flags);
1129
1130         if (!channel) {
1131                 channel = qcom_glink_create_local(glink, name);
1132                 if (IS_ERR(channel))
1133                         return NULL;
1134         } else {
1135                 ret = qcom_glink_create_remote(glink, channel);
1136                 if (ret)
1137                         return NULL;
1138         }
1139
1140         ept = &channel->ept;
1141         ept->rpdev = rpdev;
1142         ept->cb = cb;
1143         ept->priv = priv;
1144         ept->ops = &glink_endpoint_ops;
1145
1146         return ept;
1147 }
1148
1149 static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1150 {
1151         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1152         struct device_node *np = rpdev->dev.of_node;
1153         struct qcom_glink *glink = channel->glink;
1154         struct glink_core_rx_intent *intent;
1155         const struct property *prop = NULL;
1156         __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1157         int num_intents;
1158         int num_groups = 1;
1159         __be32 *val = defaults;
1160         int size;
1161
1162         if (glink->intentless)
1163                 return 0;
1164
1165         prop = of_find_property(np, "qcom,intents", NULL);
1166         if (prop) {
1167                 val = prop->value;
1168                 num_groups = prop->length / sizeof(u32) / 2;
1169         }
1170
1171         /* Channel is now open, advertise base set of intents */
1172         while (num_groups--) {
1173                 size = be32_to_cpup(val++);
1174                 num_intents = be32_to_cpup(val++);
1175                 while (num_intents--) {
1176                         intent = qcom_glink_alloc_intent(glink, channel, size,
1177                                                          true);
1178                         if (!intent)
1179                                 break;
1180
1181                         qcom_glink_advertise_intent(glink, channel, intent);
1182                 }
1183         }
1184         return 0;
1185 }
1186
1187 static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1188 {
1189         struct glink_channel *channel = to_glink_channel(ept);
1190         struct qcom_glink *glink = channel->glink;
1191         unsigned long flags;
1192
1193         spin_lock_irqsave(&channel->recv_lock, flags);
1194         channel->ept.cb = NULL;
1195         spin_unlock_irqrestore(&channel->recv_lock, flags);
1196
1197         /* Decouple the potential rpdev from the channel */
1198         channel->rpdev = NULL;
1199
1200         qcom_glink_send_close_req(glink, channel);
1201 }
1202
1203 static int qcom_glink_request_intent(struct qcom_glink *glink,
1204                                      struct glink_channel *channel,
1205                                      size_t size)
1206 {
1207         struct {
1208                 u16 id;
1209                 u16 cid;
1210                 u32 size;
1211         } __packed cmd;
1212
1213         int ret;
1214
1215         mutex_lock(&channel->intent_req_lock);
1216
1217         reinit_completion(&channel->intent_req_comp);
1218
1219         cmd.id = RPM_CMD_RX_INTENT_REQ;
1220         cmd.cid = channel->lcid;
1221         cmd.size = size;
1222
1223         ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1224         if (ret)
1225                 goto unlock;
1226
1227         ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
1228         if (!ret) {
1229                 dev_err(glink->dev, "intent request timed out\n");
1230                 ret = -ETIMEDOUT;
1231         } else {
1232                 ret = channel->intent_req_result ? 0 : -ECANCELED;
1233         }
1234
1235 unlock:
1236         mutex_unlock(&channel->intent_req_lock);
1237         return ret;
1238 }
1239
1240 static int __qcom_glink_send(struct glink_channel *channel,
1241                              void *data, int len, bool wait)
1242 {
1243         struct qcom_glink *glink = channel->glink;
1244         struct glink_core_rx_intent *intent = NULL;
1245         struct glink_core_rx_intent *tmp;
1246         int iid = 0;
1247         struct {
1248                 struct glink_msg msg;
1249                 __le32 chunk_size;
1250                 __le32 left_size;
1251         } __packed req;
1252         int ret;
1253         unsigned long flags;
1254
1255         if (!glink->intentless) {
1256                 while (!intent) {
1257                         spin_lock_irqsave(&channel->intent_lock, flags);
1258                         idr_for_each_entry(&channel->riids, tmp, iid) {
1259                                 if (tmp->size >= len && !tmp->in_use) {
1260                                         if (!intent)
1261                                                 intent = tmp;
1262                                         else if (intent->size > tmp->size)
1263                                                 intent = tmp;
1264                                         if (intent->size == len)
1265                                                 break;
1266                                 }
1267                         }
1268                         if (intent)
1269                                 intent->in_use = true;
1270                         spin_unlock_irqrestore(&channel->intent_lock, flags);
1271
1272                         /* We found an available intent */
1273                         if (intent)
1274                                 break;
1275
1276                         if (!wait)
1277                                 return -EBUSY;
1278
1279                         ret = qcom_glink_request_intent(glink, channel, len);
1280                         if (ret < 0)
1281                                 return ret;
1282                 }
1283
1284                 iid = intent->id;
1285         }
1286
1287         req.msg.cmd = cpu_to_le16(RPM_CMD_TX_DATA);
1288         req.msg.param1 = cpu_to_le16(channel->lcid);
1289         req.msg.param2 = cpu_to_le32(iid);
1290         req.chunk_size = cpu_to_le32(len);
1291         req.left_size = cpu_to_le32(0);
1292
1293         ret = qcom_glink_tx(glink, &req, sizeof(req), data, len, wait);
1294
1295         /* Mark intent available if we failed */
1296         if (ret && intent)
1297                 intent->in_use = false;
1298
1299         return ret;
1300 }
1301
1302 static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1303 {
1304         struct glink_channel *channel = to_glink_channel(ept);
1305
1306         return __qcom_glink_send(channel, data, len, true);
1307 }
1308
1309 static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1310 {
1311         struct glink_channel *channel = to_glink_channel(ept);
1312
1313         return __qcom_glink_send(channel, data, len, false);
1314 }
1315
1316 /*
1317  * Finds the device_node for the glink child interested in this channel.
1318  */
1319 static struct device_node *qcom_glink_match_channel(struct device_node *node,
1320                                                     const char *channel)
1321 {
1322         struct device_node *child;
1323         const char *name;
1324         const char *key;
1325         int ret;
1326
1327         for_each_available_child_of_node(node, child) {
1328                 key = "qcom,glink-channels";
1329                 ret = of_property_read_string(child, key, &name);
1330                 if (ret)
1331                         continue;
1332
1333                 if (strcmp(name, channel) == 0)
1334                         return child;
1335         }
1336
1337         return NULL;
1338 }
1339
1340 static const struct rpmsg_device_ops glink_device_ops = {
1341         .create_ept = qcom_glink_create_ept,
1342         .announce_create = qcom_glink_announce_create,
1343 };
1344
1345 static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1346         .destroy_ept = qcom_glink_destroy_ept,
1347         .send = qcom_glink_send,
1348         .trysend = qcom_glink_trysend,
1349 };
1350
1351 static void qcom_glink_rpdev_release(struct device *dev)
1352 {
1353         struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1354         struct glink_channel *channel = to_glink_channel(rpdev->ept);
1355
1356         channel->rpdev = NULL;
1357         kfree(rpdev);
1358 }
1359
1360 static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1361                               char *name)
1362 {
1363         struct glink_channel *channel;
1364         struct rpmsg_device *rpdev;
1365         bool create_device = false;
1366         struct device_node *node;
1367         int lcid;
1368         int ret;
1369         unsigned long flags;
1370
1371         spin_lock_irqsave(&glink->idr_lock, flags);
1372         idr_for_each_entry(&glink->lcids, channel, lcid) {
1373                 if (!strcmp(channel->name, name))
1374                         break;
1375         }
1376         spin_unlock_irqrestore(&glink->idr_lock, flags);
1377
1378         if (!channel) {
1379                 channel = qcom_glink_alloc_channel(glink, name);
1380                 if (IS_ERR(channel))
1381                         return PTR_ERR(channel);
1382
1383                 /* The opening dance was initiated by the remote */
1384                 create_device = true;
1385         }
1386
1387         spin_lock_irqsave(&glink->idr_lock, flags);
1388         ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1389         if (ret < 0) {
1390                 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1391                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1392                 goto free_channel;
1393         }
1394         channel->rcid = ret;
1395         spin_unlock_irqrestore(&glink->idr_lock, flags);
1396
1397         complete(&channel->open_req);
1398
1399         if (create_device) {
1400                 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1401                 if (!rpdev) {
1402                         ret = -ENOMEM;
1403                         goto rcid_remove;
1404                 }
1405
1406                 rpdev->ept = &channel->ept;
1407                 strncpy(rpdev->id.name, name, RPMSG_NAME_SIZE);
1408                 rpdev->src = RPMSG_ADDR_ANY;
1409                 rpdev->dst = RPMSG_ADDR_ANY;
1410                 rpdev->ops = &glink_device_ops;
1411
1412                 node = qcom_glink_match_channel(glink->dev->of_node, name);
1413                 rpdev->dev.of_node = node;
1414                 rpdev->dev.parent = glink->dev;
1415                 rpdev->dev.release = qcom_glink_rpdev_release;
1416
1417                 ret = rpmsg_register_device(rpdev);
1418                 if (ret)
1419                         goto free_rpdev;
1420
1421                 channel->rpdev = rpdev;
1422         }
1423
1424         return 0;
1425
1426 free_rpdev:
1427         kfree(rpdev);
1428 rcid_remove:
1429         spin_lock_irqsave(&glink->idr_lock, flags);
1430         idr_remove(&glink->rcids, channel->rcid);
1431         channel->rcid = 0;
1432         spin_unlock_irqrestore(&glink->idr_lock, flags);
1433 free_channel:
1434         /* Release the reference, iff we took it */
1435         if (create_device)
1436                 kref_put(&channel->refcount, qcom_glink_channel_release);
1437
1438         return ret;
1439 }
1440
1441 static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1442 {
1443         struct rpmsg_channel_info chinfo;
1444         struct glink_channel *channel;
1445         unsigned long flags;
1446
1447         spin_lock_irqsave(&glink->idr_lock, flags);
1448         channel = idr_find(&glink->rcids, rcid);
1449         spin_unlock_irqrestore(&glink->idr_lock, flags);
1450         if (WARN(!channel, "close request on unknown channel\n"))
1451                 return;
1452
1453         /* cancel pending rx_done work */
1454         cancel_work_sync(&channel->intent_work);
1455
1456         if (channel->rpdev) {
1457                 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1458                 chinfo.src = RPMSG_ADDR_ANY;
1459                 chinfo.dst = RPMSG_ADDR_ANY;
1460
1461                 rpmsg_unregister_device(glink->dev, &chinfo);
1462         }
1463
1464         qcom_glink_send_close_ack(glink, channel->rcid);
1465
1466         spin_lock_irqsave(&glink->idr_lock, flags);
1467         idr_remove(&glink->rcids, channel->rcid);
1468         channel->rcid = 0;
1469         spin_unlock_irqrestore(&glink->idr_lock, flags);
1470
1471         kref_put(&channel->refcount, qcom_glink_channel_release);
1472 }
1473
1474 static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1475 {
1476         struct glink_channel *channel;
1477         unsigned long flags;
1478
1479         spin_lock_irqsave(&glink->idr_lock, flags);
1480         channel = idr_find(&glink->lcids, lcid);
1481         if (WARN(!channel, "close ack on unknown channel\n")) {
1482                 spin_unlock_irqrestore(&glink->idr_lock, flags);
1483                 return;
1484         }
1485
1486         idr_remove(&glink->lcids, channel->lcid);
1487         channel->lcid = 0;
1488         spin_unlock_irqrestore(&glink->idr_lock, flags);
1489
1490         kref_put(&channel->refcount, qcom_glink_channel_release);
1491 }
1492
1493 static void qcom_glink_work(struct work_struct *work)
1494 {
1495         struct qcom_glink *glink = container_of(work, struct qcom_glink,
1496                                                 rx_work);
1497         struct glink_defer_cmd *dcmd;
1498         struct glink_msg *msg;
1499         unsigned long flags;
1500         unsigned int param1;
1501         unsigned int param2;
1502         unsigned int cmd;
1503
1504         for (;;) {
1505                 spin_lock_irqsave(&glink->rx_lock, flags);
1506                 if (list_empty(&glink->rx_queue)) {
1507                         spin_unlock_irqrestore(&glink->rx_lock, flags);
1508                         break;
1509                 }
1510                 dcmd = list_first_entry(&glink->rx_queue,
1511                                         struct glink_defer_cmd, node);
1512                 list_del(&dcmd->node);
1513                 spin_unlock_irqrestore(&glink->rx_lock, flags);
1514
1515                 msg = &dcmd->msg;
1516                 cmd = le16_to_cpu(msg->cmd);
1517                 param1 = le16_to_cpu(msg->param1);
1518                 param2 = le32_to_cpu(msg->param2);
1519
1520                 switch (cmd) {
1521                 case RPM_CMD_VERSION:
1522                         qcom_glink_receive_version(glink, param1, param2);
1523                         break;
1524                 case RPM_CMD_VERSION_ACK:
1525                         qcom_glink_receive_version_ack(glink, param1, param2);
1526                         break;
1527                 case RPM_CMD_OPEN:
1528                         qcom_glink_rx_open(glink, param1, msg->data);
1529                         break;
1530                 case RPM_CMD_CLOSE:
1531                         qcom_glink_rx_close(glink, param1);
1532                         break;
1533                 case RPM_CMD_CLOSE_ACK:
1534                         qcom_glink_rx_close_ack(glink, param1);
1535                         break;
1536                 case RPM_CMD_RX_INTENT_REQ:
1537                         qcom_glink_handle_intent_req(glink, param1, param2);
1538                         break;
1539                 default:
1540                         WARN(1, "Unknown defer object %d\n", cmd);
1541                         break;
1542                 }
1543
1544                 kfree(dcmd);
1545         }
1546 }
1547
1548 struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1549                                            unsigned long features,
1550                                            struct qcom_glink_pipe *rx,
1551                                            struct qcom_glink_pipe *tx,
1552                                            bool intentless)
1553 {
1554         int irq;
1555         int ret;
1556         struct qcom_glink *glink;
1557
1558         glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1559         if (!glink)
1560                 return ERR_PTR(-ENOMEM);
1561
1562         glink->dev = dev;
1563         glink->tx_pipe = tx;
1564         glink->rx_pipe = rx;
1565
1566         glink->features = features;
1567         glink->intentless = intentless;
1568
1569         mutex_init(&glink->tx_lock);
1570         spin_lock_init(&glink->rx_lock);
1571         INIT_LIST_HEAD(&glink->rx_queue);
1572         INIT_WORK(&glink->rx_work, qcom_glink_work);
1573
1574         spin_lock_init(&glink->idr_lock);
1575         idr_init(&glink->lcids);
1576         idr_init(&glink->rcids);
1577
1578         glink->mbox_client.dev = dev;
1579         glink->mbox_client.knows_txdone = true;
1580         glink->mbox_chan = mbox_request_channel(&glink->mbox_client, 0);
1581         if (IS_ERR(glink->mbox_chan)) {
1582                 if (PTR_ERR(glink->mbox_chan) != -EPROBE_DEFER)
1583                         dev_err(dev, "failed to acquire IPC channel\n");
1584                 return ERR_CAST(glink->mbox_chan);
1585         }
1586
1587         irq = of_irq_get(dev->of_node, 0);
1588         ret = devm_request_irq(dev, irq,
1589                                qcom_glink_native_intr,
1590                                IRQF_NO_SUSPEND | IRQF_SHARED,
1591                                "glink-native", glink);
1592         if (ret) {
1593                 dev_err(dev, "failed to request IRQ\n");
1594                 return ERR_PTR(ret);
1595         }
1596
1597         glink->irq = irq;
1598
1599         ret = qcom_glink_send_version(glink);
1600         if (ret)
1601                 return ERR_PTR(ret);
1602
1603         return glink;
1604 }
1605 EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1606
1607 static int qcom_glink_remove_device(struct device *dev, void *data)
1608 {
1609         device_unregister(dev);
1610
1611         return 0;
1612 }
1613
1614 void qcom_glink_native_remove(struct qcom_glink *glink)
1615 {
1616         struct glink_channel *channel;
1617         int cid;
1618         int ret;
1619         unsigned long flags;
1620
1621         disable_irq(glink->irq);
1622         cancel_work_sync(&glink->rx_work);
1623
1624         ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1625         if (ret)
1626                 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1627
1628         spin_lock_irqsave(&glink->idr_lock, flags);
1629         /* Release any defunct local channels, waiting for close-ack */
1630         idr_for_each_entry(&glink->lcids, channel, cid)
1631                 kref_put(&channel->refcount, qcom_glink_channel_release);
1632
1633         idr_destroy(&glink->lcids);
1634         idr_destroy(&glink->rcids);
1635         spin_unlock_irqrestore(&glink->idr_lock, flags);
1636         mbox_free_channel(glink->mbox_chan);
1637 }
1638 EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1639
1640 void qcom_glink_native_unregister(struct qcom_glink *glink)
1641 {
1642         device_unregister(glink->dev);
1643 }
1644 EXPORT_SYMBOL_GPL(qcom_glink_native_unregister);
1645
1646 MODULE_DESCRIPTION("Qualcomm GLINK driver");
1647 MODULE_LICENSE("GPL v2");