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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/platform_device.h>
15#include <linux/regmap.h>
16#include <linux/rpmsg.h>
17#include <linux/sizes.h>
18#include <linux/slab.h>
19#include <linux/wait.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 * @rx_pipe: pipe object for receive FIFO
82 * @tx_pipe: pipe object for transmit FIFO
83 * @rx_work: worker for handling received control messages
84 * @rx_lock: protects the @rx_queue
85 * @rx_queue: queue of received control messages to be processed in @rx_work
86 * @tx_lock: synchronizes operations on the tx fifo
87 * @idr_lock: synchronizes @lcids and @rcids modifications
88 * @lcids: idr of all channels with a known local channel id
89 * @rcids: idr of all channels with a known remote channel id
90 * @features: remote features
91 * @intentless: flag to indicate that there is no intent
92 * @tx_avail_notify: Waitqueue for pending tx tasks
93 * @sent_read_notify: flag to check cmd sent or not
94 * @abort_tx: flag indicating that all tx attempts should fail
95 */
96struct qcom_glink {
97 struct device *dev;
98
99 struct qcom_glink_pipe *rx_pipe;
100 struct qcom_glink_pipe *tx_pipe;
101
102 struct work_struct rx_work;
103 spinlock_t rx_lock;
104 struct list_head rx_queue;
105
106 spinlock_t tx_lock;
107
108 spinlock_t idr_lock;
109 struct idr lcids;
110 struct idr rcids;
111 unsigned long features;
112
113 bool intentless;
114 wait_queue_head_t tx_avail_notify;
115 bool sent_read_notify;
116
117 bool abort_tx;
118};
119
120enum {
121 GLINK_STATE_CLOSED,
122 GLINK_STATE_OPENING,
123 GLINK_STATE_OPEN,
124 GLINK_STATE_CLOSING,
125};
126
127/**
128 * struct glink_channel - internal representation of a channel
129 * @rpdev: rpdev reference, only used for primary endpoints
130 * @ept: rpmsg endpoint this channel is associated with
131 * @glink: qcom_glink context handle
132 * @refcount: refcount for the channel object
133 * @recv_lock: guard for @ept.cb
134 * @name: unique channel name/identifier
135 * @lcid: channel id, in local space
136 * @rcid: channel id, in remote space
137 * @intent_lock: lock for protection of @liids, @riids
138 * @liids: idr of all local intents
139 * @riids: idr of all remote intents
140 * @intent_work: worker responsible for transmitting rx_done packets
141 * @done_intents: list of intents that needs to be announced rx_done
142 * @buf: receive buffer, for gathering fragments
143 * @buf_offset: write offset in @buf
144 * @buf_size: size of current @buf
145 * @open_ack: completed once remote has acked the open-request
146 * @open_req: completed once open-request has been received
147 * @intent_req_lock: Synchronises multiple intent requests
148 * @intent_req_result: Result of intent request
149 * @intent_received: flag indicating that an intent has been received
150 * @intent_req_wq: wait queue for intent_req signalling
151 */
152struct glink_channel {
153 struct rpmsg_endpoint ept;
154
155 struct rpmsg_device *rpdev;
156 struct qcom_glink *glink;
157
158 struct kref refcount;
159
160 spinlock_t recv_lock;
161
162 char *name;
163 unsigned int lcid;
164 unsigned int rcid;
165
166 spinlock_t intent_lock;
167 struct idr liids;
168 struct idr riids;
169 struct work_struct intent_work;
170 struct list_head done_intents;
171
172 struct glink_core_rx_intent *buf;
173 int buf_offset;
174 int buf_size;
175
176 struct completion open_ack;
177 struct completion open_req;
178
179 struct mutex intent_req_lock;
180 int intent_req_result;
181 bool intent_received;
182 wait_queue_head_t intent_req_wq;
183};
184
185#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
186
187static const struct rpmsg_endpoint_ops glink_endpoint_ops;
188
189#define GLINK_CMD_VERSION 0
190#define GLINK_CMD_VERSION_ACK 1
191#define GLINK_CMD_OPEN 2
192#define GLINK_CMD_CLOSE 3
193#define GLINK_CMD_OPEN_ACK 4
194#define GLINK_CMD_INTENT 5
195#define GLINK_CMD_RX_DONE 6
196#define GLINK_CMD_RX_INTENT_REQ 7
197#define GLINK_CMD_RX_INTENT_REQ_ACK 8
198#define GLINK_CMD_TX_DATA 9
199#define GLINK_CMD_CLOSE_ACK 11
200#define GLINK_CMD_TX_DATA_CONT 12
201#define GLINK_CMD_READ_NOTIF 13
202#define GLINK_CMD_RX_DONE_W_REUSE 14
203#define GLINK_CMD_SIGNALS 15
204
205#define GLINK_FEATURE_INTENTLESS BIT(1)
206
207#define NATIVE_DTR_SIG NATIVE_DSR_SIG
208#define NATIVE_DSR_SIG BIT(31)
209#define NATIVE_RTS_SIG NATIVE_CTS_SIG
210#define NATIVE_CTS_SIG BIT(30)
211
212static void qcom_glink_rx_done_work(struct work_struct *work);
213
214static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
215 const char *name)
216{
217 struct glink_channel *channel;
218
219 channel = kzalloc(sizeof(*channel), GFP_KERNEL);
220 if (!channel)
221 return ERR_PTR(-ENOMEM);
222
223 /* Setup glink internal glink_channel data */
224 spin_lock_init(&channel->recv_lock);
225 spin_lock_init(&channel->intent_lock);
226 mutex_init(&channel->intent_req_lock);
227
228 channel->glink = glink;
229 channel->name = kstrdup(name, GFP_KERNEL);
230 if (!channel->name) {
231 kfree(channel);
232 return ERR_PTR(-ENOMEM);
233 }
234
235 init_completion(&channel->open_req);
236 init_completion(&channel->open_ack);
237 init_waitqueue_head(&channel->intent_req_wq);
238
239 INIT_LIST_HEAD(&channel->done_intents);
240 INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
241
242 idr_init(&channel->liids);
243 idr_init(&channel->riids);
244 kref_init(&channel->refcount);
245
246 return channel;
247}
248
249static void qcom_glink_channel_release(struct kref *ref)
250{
251 struct glink_channel *channel = container_of(ref, struct glink_channel,
252 refcount);
253 struct glink_core_rx_intent *intent;
254 struct glink_core_rx_intent *tmp;
255 unsigned long flags;
256 int iid;
257
258 /* cancel pending rx_done work */
259 cancel_work_sync(&channel->intent_work);
260
261 spin_lock_irqsave(&channel->intent_lock, flags);
262 /* Free all non-reuse intents pending rx_done work */
263 list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
264 if (!intent->reuse) {
265 kfree(intent->data);
266 kfree(intent);
267 }
268 }
269
270 idr_for_each_entry(&channel->liids, tmp, iid) {
271 kfree(tmp->data);
272 kfree(tmp);
273 }
274 idr_destroy(&channel->liids);
275
276 idr_for_each_entry(&channel->riids, tmp, iid)
277 kfree(tmp);
278 idr_destroy(&channel->riids);
279 spin_unlock_irqrestore(&channel->intent_lock, flags);
280
281 kfree(channel->name);
282 kfree(channel);
283}
284
285static size_t qcom_glink_rx_avail(struct qcom_glink *glink)
286{
287 return glink->rx_pipe->avail(glink->rx_pipe);
288}
289
290static void qcom_glink_rx_peek(struct qcom_glink *glink,
291 void *data, unsigned int offset, size_t count)
292{
293 glink->rx_pipe->peek(glink->rx_pipe, data, offset, count);
294}
295
296static void qcom_glink_rx_advance(struct qcom_glink *glink, size_t count)
297{
298 glink->rx_pipe->advance(glink->rx_pipe, count);
299}
300
301static size_t qcom_glink_tx_avail(struct qcom_glink *glink)
302{
303 return glink->tx_pipe->avail(glink->tx_pipe);
304}
305
306static void qcom_glink_tx_write(struct qcom_glink *glink,
307 const void *hdr, size_t hlen,
308 const void *data, size_t dlen)
309{
310 glink->tx_pipe->write(glink->tx_pipe, hdr, hlen, data, dlen);
311}
312
313static void qcom_glink_tx_kick(struct qcom_glink *glink)
314{
315 glink->tx_pipe->kick(glink->tx_pipe);
316}
317
318static void qcom_glink_send_read_notify(struct qcom_glink *glink)
319{
320 struct glink_msg msg;
321
322 msg.cmd = cpu_to_le16(GLINK_CMD_READ_NOTIF);
323 msg.param1 = 0;
324 msg.param2 = 0;
325
326 qcom_glink_tx_write(glink, &msg, sizeof(msg), NULL, 0);
327
328 qcom_glink_tx_kick(glink);
329}
330
331static int qcom_glink_tx(struct qcom_glink *glink,
332 const void *hdr, size_t hlen,
333 const void *data, size_t dlen, bool wait)
334{
335 unsigned int tlen = hlen + dlen;
336 unsigned long flags;
337 int ret = 0;
338
339 /* Reject packets that are too big */
340 if (tlen >= glink->tx_pipe->length)
341 return -EINVAL;
342
343 spin_lock_irqsave(&glink->tx_lock, flags);
344
345 if (glink->abort_tx) {
346 ret = -EIO;
347 goto out;
348 }
349
350 while (qcom_glink_tx_avail(glink) < tlen) {
351 if (!wait) {
352 ret = -EAGAIN;
353 goto out;
354 }
355
356 if (glink->abort_tx) {
357 ret = -EIO;
358 goto out;
359 }
360
361 if (!glink->sent_read_notify) {
362 glink->sent_read_notify = true;
363 qcom_glink_send_read_notify(glink);
364 }
365
366 /* Wait without holding the tx_lock */
367 spin_unlock_irqrestore(&glink->tx_lock, flags);
368
369 wait_event_timeout(glink->tx_avail_notify,
370 qcom_glink_tx_avail(glink) >= tlen, 10 * HZ);
371
372 spin_lock_irqsave(&glink->tx_lock, flags);
373
374 if (qcom_glink_tx_avail(glink) >= tlen)
375 glink->sent_read_notify = false;
376 }
377
378 qcom_glink_tx_write(glink, hdr, hlen, data, dlen);
379 qcom_glink_tx_kick(glink);
380
381out:
382 spin_unlock_irqrestore(&glink->tx_lock, flags);
383
384 return ret;
385}
386
387static int qcom_glink_send_version(struct qcom_glink *glink)
388{
389 struct glink_msg msg;
390
391 msg.cmd = cpu_to_le16(GLINK_CMD_VERSION);
392 msg.param1 = cpu_to_le16(GLINK_VERSION_1);
393 msg.param2 = cpu_to_le32(glink->features);
394
395 return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
396}
397
398static void qcom_glink_send_version_ack(struct qcom_glink *glink)
399{
400 struct glink_msg msg;
401
402 msg.cmd = cpu_to_le16(GLINK_CMD_VERSION_ACK);
403 msg.param1 = cpu_to_le16(GLINK_VERSION_1);
404 msg.param2 = cpu_to_le32(glink->features);
405
406 qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
407}
408
409static void qcom_glink_send_open_ack(struct qcom_glink *glink,
410 struct glink_channel *channel)
411{
412 struct glink_msg msg;
413
414 msg.cmd = cpu_to_le16(GLINK_CMD_OPEN_ACK);
415 msg.param1 = cpu_to_le16(channel->rcid);
416 msg.param2 = cpu_to_le32(0);
417
418 qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
419}
420
421static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
422 unsigned int cid, bool granted)
423{
424 struct glink_channel *channel;
425 unsigned long flags;
426
427 spin_lock_irqsave(&glink->idr_lock, flags);
428 channel = idr_find(&glink->rcids, cid);
429 spin_unlock_irqrestore(&glink->idr_lock, flags);
430 if (!channel) {
431 dev_err(glink->dev, "unable to find channel\n");
432 return;
433 }
434
435 WRITE_ONCE(channel->intent_req_result, granted);
436 wake_up_all(&channel->intent_req_wq);
437}
438
439static void qcom_glink_intent_req_abort(struct glink_channel *channel)
440{
441 WRITE_ONCE(channel->intent_req_result, 0);
442 wake_up_all(&channel->intent_req_wq);
443}
444
445/**
446 * qcom_glink_send_open_req() - send a GLINK_CMD_OPEN request to the remote
447 * @glink: Ptr to the glink edge
448 * @channel: Ptr to the channel that the open req is sent
449 *
450 * Allocates a local channel id and sends a GLINK_CMD_OPEN message to the remote.
451 * Will return with refcount held, regardless of outcome.
452 *
453 * Return: 0 on success, negative errno otherwise.
454 */
455static int qcom_glink_send_open_req(struct qcom_glink *glink,
456 struct glink_channel *channel)
457{
458 struct {
459 struct glink_msg msg;
460 u8 name[GLINK_NAME_SIZE];
461 } __packed req;
462 int name_len = strlen(channel->name) + 1;
463 int req_len = ALIGN(sizeof(req.msg) + name_len, 8);
464 int ret;
465 unsigned long flags;
466
467 kref_get(&channel->refcount);
468
469 spin_lock_irqsave(&glink->idr_lock, flags);
470 ret = idr_alloc_cyclic(&glink->lcids, channel,
471 RPM_GLINK_CID_MIN, RPM_GLINK_CID_MAX,
472 GFP_ATOMIC);
473 spin_unlock_irqrestore(&glink->idr_lock, flags);
474 if (ret < 0)
475 return ret;
476
477 channel->lcid = ret;
478
479 req.msg.cmd = cpu_to_le16(GLINK_CMD_OPEN);
480 req.msg.param1 = cpu_to_le16(channel->lcid);
481 req.msg.param2 = cpu_to_le32(name_len);
482 strcpy(req.name, channel->name);
483
484 ret = qcom_glink_tx(glink, &req, req_len, NULL, 0, true);
485 if (ret)
486 goto remove_idr;
487
488 return 0;
489
490remove_idr:
491 spin_lock_irqsave(&glink->idr_lock, flags);
492 idr_remove(&glink->lcids, channel->lcid);
493 channel->lcid = 0;
494 spin_unlock_irqrestore(&glink->idr_lock, flags);
495
496 return ret;
497}
498
499static void qcom_glink_send_close_req(struct qcom_glink *glink,
500 struct glink_channel *channel)
501{
502 struct glink_msg req;
503
504 req.cmd = cpu_to_le16(GLINK_CMD_CLOSE);
505 req.param1 = cpu_to_le16(channel->lcid);
506 req.param2 = 0;
507
508 qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
509}
510
511static void qcom_glink_send_close_ack(struct qcom_glink *glink,
512 unsigned int rcid)
513{
514 struct glink_msg req;
515
516 req.cmd = cpu_to_le16(GLINK_CMD_CLOSE_ACK);
517 req.param1 = cpu_to_le16(rcid);
518 req.param2 = 0;
519
520 qcom_glink_tx(glink, &req, sizeof(req), NULL, 0, true);
521}
522
523static void qcom_glink_rx_done_work(struct work_struct *work)
524{
525 struct glink_channel *channel = container_of(work, struct glink_channel,
526 intent_work);
527 struct qcom_glink *glink = channel->glink;
528 struct glink_core_rx_intent *intent, *tmp;
529 struct {
530 u16 id;
531 u16 lcid;
532 u32 liid;
533 } __packed cmd;
534
535 unsigned int cid = channel->lcid;
536 unsigned int iid;
537 bool reuse;
538 unsigned long flags;
539
540 spin_lock_irqsave(&channel->intent_lock, flags);
541 list_for_each_entry_safe(intent, tmp, &channel->done_intents, node) {
542 list_del(&intent->node);
543 spin_unlock_irqrestore(&channel->intent_lock, flags);
544 iid = intent->id;
545 reuse = intent->reuse;
546
547 cmd.id = reuse ? GLINK_CMD_RX_DONE_W_REUSE : GLINK_CMD_RX_DONE;
548 cmd.lcid = cid;
549 cmd.liid = iid;
550
551 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
552 if (!reuse) {
553 kfree(intent->data);
554 kfree(intent);
555 }
556 spin_lock_irqsave(&channel->intent_lock, flags);
557 }
558 spin_unlock_irqrestore(&channel->intent_lock, flags);
559}
560
561static void qcom_glink_rx_done(struct qcom_glink *glink,
562 struct glink_channel *channel,
563 struct glink_core_rx_intent *intent)
564{
565 /* We don't send RX_DONE to intentless systems */
566 if (glink->intentless) {
567 kfree(intent->data);
568 kfree(intent);
569 return;
570 }
571
572 /* Take it off the tree of receive intents */
573 if (!intent->reuse) {
574 spin_lock(&channel->intent_lock);
575 idr_remove(&channel->liids, intent->id);
576 spin_unlock(&channel->intent_lock);
577 }
578
579 /* Schedule the sending of a rx_done indication */
580 spin_lock(&channel->intent_lock);
581 list_add_tail(&intent->node, &channel->done_intents);
582 spin_unlock(&channel->intent_lock);
583
584 schedule_work(&channel->intent_work);
585}
586
587/**
588 * qcom_glink_receive_version() - receive version/features from remote system
589 *
590 * @glink: pointer to transport interface
591 * @version: remote version
592 * @features: remote features
593 *
594 * This function is called in response to a remote-initiated version/feature
595 * negotiation sequence.
596 */
597static void qcom_glink_receive_version(struct qcom_glink *glink,
598 u32 version,
599 u32 features)
600{
601 switch (version) {
602 case 0:
603 break;
604 case GLINK_VERSION_1:
605 glink->features &= features;
606 fallthrough;
607 default:
608 qcom_glink_send_version_ack(glink);
609 break;
610 }
611}
612
613/**
614 * qcom_glink_receive_version_ack() - receive negotiation ack from remote system
615 *
616 * @glink: pointer to transport interface
617 * @version: remote version response
618 * @features: remote features response
619 *
620 * This function is called in response to a local-initiated version/feature
621 * negotiation sequence and is the counter-offer from the remote side based
622 * upon the initial version and feature set requested.
623 */
624static void qcom_glink_receive_version_ack(struct qcom_glink *glink,
625 u32 version,
626 u32 features)
627{
628 switch (version) {
629 case 0:
630 /* Version negotiation failed */
631 break;
632 case GLINK_VERSION_1:
633 if (features == glink->features)
634 break;
635
636 glink->features &= features;
637 fallthrough;
638 default:
639 qcom_glink_send_version(glink);
640 break;
641 }
642}
643
644/**
645 * qcom_glink_send_intent_req_ack() - convert an rx intent request ack cmd to
646 * wire format and transmit
647 * @glink: The transport to transmit on.
648 * @channel: The glink channel
649 * @granted: The request response to encode.
650 *
651 * Return: 0 on success or standard Linux error code.
652 */
653static int qcom_glink_send_intent_req_ack(struct qcom_glink *glink,
654 struct glink_channel *channel,
655 bool granted)
656{
657 struct glink_msg msg;
658
659 msg.cmd = cpu_to_le16(GLINK_CMD_RX_INTENT_REQ_ACK);
660 msg.param1 = cpu_to_le16(channel->lcid);
661 msg.param2 = cpu_to_le32(granted);
662
663 qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
664
665 return 0;
666}
667
668/**
669 * qcom_glink_advertise_intent - convert an rx intent cmd to wire format and
670 * transmit
671 * @glink: The transport to transmit on.
672 * @channel: The local channel
673 * @intent: The intent to pass on to remote.
674 *
675 * Return: 0 on success or standard Linux error code.
676 */
677static int qcom_glink_advertise_intent(struct qcom_glink *glink,
678 struct glink_channel *channel,
679 struct glink_core_rx_intent *intent)
680{
681 struct command {
682 __le16 id;
683 __le16 lcid;
684 __le32 count;
685 __le32 size;
686 __le32 liid;
687 } __packed;
688 struct command cmd;
689
690 cmd.id = cpu_to_le16(GLINK_CMD_INTENT);
691 cmd.lcid = cpu_to_le16(channel->lcid);
692 cmd.count = cpu_to_le32(1);
693 cmd.size = cpu_to_le32(intent->size);
694 cmd.liid = cpu_to_le32(intent->id);
695
696 qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
697
698 return 0;
699}
700
701static struct glink_core_rx_intent *
702qcom_glink_alloc_intent(struct qcom_glink *glink,
703 struct glink_channel *channel,
704 size_t size,
705 bool reuseable)
706{
707 struct glink_core_rx_intent *intent;
708 int ret;
709 unsigned long flags;
710
711 intent = kzalloc(sizeof(*intent), GFP_KERNEL);
712 if (!intent)
713 return NULL;
714
715 intent->data = kzalloc(size, GFP_KERNEL);
716 if (!intent->data)
717 goto free_intent;
718
719 spin_lock_irqsave(&channel->intent_lock, flags);
720 ret = idr_alloc_cyclic(&channel->liids, intent, 1, -1, GFP_ATOMIC);
721 if (ret < 0) {
722 spin_unlock_irqrestore(&channel->intent_lock, flags);
723 goto free_data;
724 }
725 spin_unlock_irqrestore(&channel->intent_lock, flags);
726
727 intent->id = ret;
728 intent->size = size;
729 intent->reuse = reuseable;
730
731 return intent;
732
733free_data:
734 kfree(intent->data);
735free_intent:
736 kfree(intent);
737 return NULL;
738}
739
740static void qcom_glink_handle_rx_done(struct qcom_glink *glink,
741 u32 cid, uint32_t iid,
742 bool reuse)
743{
744 struct glink_core_rx_intent *intent;
745 struct glink_channel *channel;
746 unsigned long flags;
747
748 spin_lock_irqsave(&glink->idr_lock, flags);
749 channel = idr_find(&glink->rcids, cid);
750 spin_unlock_irqrestore(&glink->idr_lock, flags);
751 if (!channel) {
752 dev_err(glink->dev, "invalid channel id received\n");
753 return;
754 }
755
756 spin_lock_irqsave(&channel->intent_lock, flags);
757 intent = idr_find(&channel->riids, iid);
758
759 if (!intent) {
760 spin_unlock_irqrestore(&channel->intent_lock, flags);
761 dev_err(glink->dev, "invalid intent id received\n");
762 return;
763 }
764
765 intent->in_use = false;
766
767 if (!reuse) {
768 idr_remove(&channel->riids, intent->id);
769 kfree(intent);
770 }
771 spin_unlock_irqrestore(&channel->intent_lock, flags);
772
773 if (reuse) {
774 WRITE_ONCE(channel->intent_received, true);
775 wake_up_all(&channel->intent_req_wq);
776 }
777}
778
779/**
780 * qcom_glink_handle_intent_req() - Receive a request for rx_intent
781 * from remote side
782 * @glink: Pointer to the transport interface
783 * @cid: Remote channel ID
784 * @size: size of the intent
785 *
786 * The function searches for the local channel to which the request for
787 * rx_intent has arrived and allocates and notifies the remote back
788 */
789static void qcom_glink_handle_intent_req(struct qcom_glink *glink,
790 u32 cid, size_t size)
791{
792 struct glink_core_rx_intent *intent;
793 struct glink_channel *channel;
794 unsigned long flags;
795
796 spin_lock_irqsave(&glink->idr_lock, flags);
797 channel = idr_find(&glink->rcids, cid);
798 spin_unlock_irqrestore(&glink->idr_lock, flags);
799
800 if (!channel) {
801 pr_err("%s channel not found for cid %d\n", __func__, cid);
802 return;
803 }
804
805 intent = qcom_glink_alloc_intent(glink, channel, size, false);
806 if (intent)
807 qcom_glink_advertise_intent(glink, channel, intent);
808
809 qcom_glink_send_intent_req_ack(glink, channel, !!intent);
810}
811
812static int qcom_glink_rx_defer(struct qcom_glink *glink, size_t extra)
813{
814 struct glink_defer_cmd *dcmd;
815
816 extra = ALIGN(extra, 8);
817
818 if (qcom_glink_rx_avail(glink) < sizeof(struct glink_msg) + extra) {
819 dev_dbg(glink->dev, "Insufficient data in rx fifo");
820 return -ENXIO;
821 }
822
823 dcmd = kzalloc(struct_size(dcmd, data, extra), GFP_ATOMIC);
824 if (!dcmd)
825 return -ENOMEM;
826
827 INIT_LIST_HEAD(&dcmd->node);
828
829 qcom_glink_rx_peek(glink, &dcmd->msg, 0, sizeof(dcmd->msg) + extra);
830
831 spin_lock(&glink->rx_lock);
832 list_add_tail(&dcmd->node, &glink->rx_queue);
833 spin_unlock(&glink->rx_lock);
834
835 schedule_work(&glink->rx_work);
836 qcom_glink_rx_advance(glink, sizeof(dcmd->msg) + extra);
837
838 return 0;
839}
840
841static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
842{
843 struct glink_core_rx_intent *intent;
844 struct glink_channel *channel;
845 struct {
846 struct glink_msg msg;
847 __le32 chunk_size;
848 __le32 left_size;
849 } __packed hdr;
850 unsigned int chunk_size;
851 unsigned int left_size;
852 unsigned int rcid;
853 unsigned int liid;
854 int ret = 0;
855 unsigned long flags;
856
857 if (avail < sizeof(hdr)) {
858 dev_dbg(glink->dev, "Not enough data in fifo\n");
859 return -EAGAIN;
860 }
861
862 qcom_glink_rx_peek(glink, &hdr, 0, sizeof(hdr));
863 chunk_size = le32_to_cpu(hdr.chunk_size);
864 left_size = le32_to_cpu(hdr.left_size);
865
866 if (avail < sizeof(hdr) + chunk_size) {
867 dev_dbg(glink->dev, "Payload not yet in fifo\n");
868 return -EAGAIN;
869 }
870
871 rcid = le16_to_cpu(hdr.msg.param1);
872 spin_lock_irqsave(&glink->idr_lock, flags);
873 channel = idr_find(&glink->rcids, rcid);
874 spin_unlock_irqrestore(&glink->idr_lock, flags);
875 if (!channel) {
876 dev_dbg(glink->dev, "Data on non-existing channel\n");
877
878 /* Drop the message */
879 goto advance_rx;
880 }
881
882 if (glink->intentless) {
883 /* Might have an ongoing, fragmented, message to append */
884 if (!channel->buf) {
885 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
886 if (!intent)
887 return -ENOMEM;
888
889 intent->data = kmalloc(chunk_size + left_size,
890 GFP_ATOMIC);
891 if (!intent->data) {
892 kfree(intent);
893 return -ENOMEM;
894 }
895
896 intent->id = 0xbabababa;
897 intent->size = chunk_size + left_size;
898 intent->offset = 0;
899
900 channel->buf = intent;
901 } else {
902 intent = channel->buf;
903 }
904 } else {
905 liid = le32_to_cpu(hdr.msg.param2);
906
907 spin_lock_irqsave(&channel->intent_lock, flags);
908 intent = idr_find(&channel->liids, liid);
909 spin_unlock_irqrestore(&channel->intent_lock, flags);
910
911 if (!intent) {
912 dev_err(glink->dev,
913 "no intent found for channel %s intent %d",
914 channel->name, liid);
915 ret = -ENOENT;
916 goto advance_rx;
917 }
918 }
919
920 if (intent->size - intent->offset < chunk_size) {
921 dev_err(glink->dev, "Insufficient space in intent\n");
922
923 /* The packet header lied, drop payload */
924 goto advance_rx;
925 }
926
927 qcom_glink_rx_peek(glink, intent->data + intent->offset,
928 sizeof(hdr), chunk_size);
929 intent->offset += chunk_size;
930
931 /* Handle message when no fragments remain to be received */
932 if (!left_size) {
933 spin_lock(&channel->recv_lock);
934 if (channel->ept.cb) {
935 channel->ept.cb(channel->ept.rpdev,
936 intent->data,
937 intent->offset,
938 channel->ept.priv,
939 RPMSG_ADDR_ANY);
940 }
941 spin_unlock(&channel->recv_lock);
942
943 intent->offset = 0;
944 channel->buf = NULL;
945
946 qcom_glink_rx_done(glink, channel, intent);
947 }
948
949advance_rx:
950 qcom_glink_rx_advance(glink, ALIGN(sizeof(hdr) + chunk_size, 8));
951
952 return ret;
953}
954
955static void qcom_glink_handle_intent(struct qcom_glink *glink,
956 unsigned int cid,
957 unsigned int count,
958 size_t avail)
959{
960 struct glink_core_rx_intent *intent;
961 struct glink_channel *channel;
962 struct intent_pair {
963 __le32 size;
964 __le32 iid;
965 };
966
967 struct {
968 struct glink_msg msg;
969 struct intent_pair intents[];
970 } __packed * msg;
971
972 const size_t msglen = struct_size(msg, intents, count);
973 int ret;
974 int i;
975 unsigned long flags;
976
977 if (avail < msglen) {
978 dev_dbg(glink->dev, "Not enough data in fifo\n");
979 return;
980 }
981
982 spin_lock_irqsave(&glink->idr_lock, flags);
983 channel = idr_find(&glink->rcids, cid);
984 spin_unlock_irqrestore(&glink->idr_lock, flags);
985 if (!channel) {
986 dev_err(glink->dev, "intents for non-existing channel\n");
987 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
988 return;
989 }
990
991 msg = kmalloc(msglen, GFP_ATOMIC);
992 if (!msg)
993 return;
994
995 qcom_glink_rx_peek(glink, msg, 0, msglen);
996
997 for (i = 0; i < count; ++i) {
998 intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
999 if (!intent)
1000 break;
1001
1002 intent->id = le32_to_cpu(msg->intents[i].iid);
1003 intent->size = le32_to_cpu(msg->intents[i].size);
1004
1005 spin_lock_irqsave(&channel->intent_lock, flags);
1006 ret = idr_alloc(&channel->riids, intent,
1007 intent->id, intent->id + 1, GFP_ATOMIC);
1008 spin_unlock_irqrestore(&channel->intent_lock, flags);
1009
1010 if (ret < 0)
1011 dev_err(glink->dev, "failed to store remote intent\n");
1012 }
1013
1014 WRITE_ONCE(channel->intent_received, true);
1015 wake_up_all(&channel->intent_req_wq);
1016
1017 kfree(msg);
1018 qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
1019}
1020
1021static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
1022{
1023 struct glink_channel *channel;
1024
1025 spin_lock(&glink->idr_lock);
1026 channel = idr_find(&glink->lcids, lcid);
1027 spin_unlock(&glink->idr_lock);
1028 if (!channel) {
1029 dev_err(glink->dev, "Invalid open ack packet\n");
1030 return -EINVAL;
1031 }
1032
1033 complete_all(&channel->open_ack);
1034
1035 return 0;
1036}
1037
1038/**
1039 * qcom_glink_set_flow_control() - convert a signal cmd to wire format and transmit
1040 * @ept: Rpmsg endpoint for channel.
1041 * @pause: Pause transmission
1042 * @dst: destination address of the endpoint
1043 *
1044 * Return: 0 on success or standard Linux error code.
1045 */
1046static int qcom_glink_set_flow_control(struct rpmsg_endpoint *ept, bool pause, u32 dst)
1047{
1048 struct glink_channel *channel = to_glink_channel(ept);
1049 struct qcom_glink *glink = channel->glink;
1050 struct glink_msg msg;
1051 u32 sigs = 0;
1052
1053 if (pause)
1054 sigs |= NATIVE_DTR_SIG | NATIVE_RTS_SIG;
1055
1056 msg.cmd = cpu_to_le16(GLINK_CMD_SIGNALS);
1057 msg.param1 = cpu_to_le16(channel->lcid);
1058 msg.param2 = cpu_to_le32(sigs);
1059
1060 return qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
1061}
1062
1063static void qcom_glink_handle_signals(struct qcom_glink *glink,
1064 unsigned int rcid, unsigned int sigs)
1065{
1066 struct glink_channel *channel;
1067 unsigned long flags;
1068 bool enable;
1069
1070 spin_lock_irqsave(&glink->idr_lock, flags);
1071 channel = idr_find(&glink->rcids, rcid);
1072 spin_unlock_irqrestore(&glink->idr_lock, flags);
1073 if (!channel) {
1074 dev_err(glink->dev, "signal for non-existing channel\n");
1075 return;
1076 }
1077
1078 enable = sigs & NATIVE_DSR_SIG || sigs & NATIVE_CTS_SIG;
1079
1080 if (channel->ept.flow_cb)
1081 channel->ept.flow_cb(channel->ept.rpdev, channel->ept.priv, enable);
1082}
1083
1084void qcom_glink_native_rx(struct qcom_glink *glink)
1085{
1086 struct glink_msg msg;
1087 unsigned int param1;
1088 unsigned int param2;
1089 unsigned int avail;
1090 unsigned int cmd;
1091 int ret = 0;
1092
1093 /* To wakeup any blocking writers */
1094 wake_up_all(&glink->tx_avail_notify);
1095
1096 for (;;) {
1097 avail = qcom_glink_rx_avail(glink);
1098 if (avail < sizeof(msg))
1099 break;
1100
1101 qcom_glink_rx_peek(glink, &msg, 0, sizeof(msg));
1102
1103 cmd = le16_to_cpu(msg.cmd);
1104 param1 = le16_to_cpu(msg.param1);
1105 param2 = le32_to_cpu(msg.param2);
1106
1107 switch (cmd) {
1108 case GLINK_CMD_VERSION:
1109 case GLINK_CMD_VERSION_ACK:
1110 case GLINK_CMD_CLOSE:
1111 case GLINK_CMD_CLOSE_ACK:
1112 case GLINK_CMD_RX_INTENT_REQ:
1113 ret = qcom_glink_rx_defer(glink, 0);
1114 break;
1115 case GLINK_CMD_OPEN_ACK:
1116 ret = qcom_glink_rx_open_ack(glink, param1);
1117 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1118 break;
1119 case GLINK_CMD_OPEN:
1120 ret = qcom_glink_rx_defer(glink, param2);
1121 break;
1122 case GLINK_CMD_TX_DATA:
1123 case GLINK_CMD_TX_DATA_CONT:
1124 ret = qcom_glink_rx_data(glink, avail);
1125 break;
1126 case GLINK_CMD_READ_NOTIF:
1127 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1128 qcom_glink_tx_kick(glink);
1129 break;
1130 case GLINK_CMD_INTENT:
1131 qcom_glink_handle_intent(glink, param1, param2, avail);
1132 break;
1133 case GLINK_CMD_RX_DONE:
1134 qcom_glink_handle_rx_done(glink, param1, param2, false);
1135 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1136 break;
1137 case GLINK_CMD_RX_DONE_W_REUSE:
1138 qcom_glink_handle_rx_done(glink, param1, param2, true);
1139 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1140 break;
1141 case GLINK_CMD_RX_INTENT_REQ_ACK:
1142 qcom_glink_handle_intent_req_ack(glink, param1, param2);
1143 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1144 break;
1145 case GLINK_CMD_SIGNALS:
1146 qcom_glink_handle_signals(glink, param1, param2);
1147 qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
1148 break;
1149 default:
1150 dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
1151 ret = -EINVAL;
1152 break;
1153 }
1154
1155 if (ret)
1156 break;
1157 }
1158}
1159EXPORT_SYMBOL(qcom_glink_native_rx);
1160
1161/* Locally initiated rpmsg_create_ept */
1162static struct glink_channel *qcom_glink_create_local(struct qcom_glink *glink,
1163 const char *name)
1164{
1165 struct glink_channel *channel;
1166 int ret;
1167 unsigned long flags;
1168
1169 channel = qcom_glink_alloc_channel(glink, name);
1170 if (IS_ERR(channel))
1171 return ERR_CAST(channel);
1172
1173 ret = qcom_glink_send_open_req(glink, channel);
1174 if (ret)
1175 goto release_channel;
1176
1177 ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1178 if (!ret)
1179 goto err_timeout;
1180
1181 ret = wait_for_completion_timeout(&channel->open_req, 5 * HZ);
1182 if (!ret)
1183 goto err_timeout;
1184
1185 qcom_glink_send_open_ack(glink, channel);
1186
1187 return channel;
1188
1189err_timeout:
1190 /* qcom_glink_send_open_req() did register the channel in lcids*/
1191 spin_lock_irqsave(&glink->idr_lock, flags);
1192 idr_remove(&glink->lcids, channel->lcid);
1193 spin_unlock_irqrestore(&glink->idr_lock, flags);
1194
1195release_channel:
1196 /* Release qcom_glink_send_open_req() reference */
1197 kref_put(&channel->refcount, qcom_glink_channel_release);
1198 /* Release qcom_glink_alloc_channel() reference */
1199 kref_put(&channel->refcount, qcom_glink_channel_release);
1200
1201 return ERR_PTR(-ETIMEDOUT);
1202}
1203
1204/* Remote initiated rpmsg_create_ept */
1205static int qcom_glink_create_remote(struct qcom_glink *glink,
1206 struct glink_channel *channel)
1207{
1208 int ret;
1209
1210 qcom_glink_send_open_ack(glink, channel);
1211
1212 ret = qcom_glink_send_open_req(glink, channel);
1213 if (ret)
1214 goto close_link;
1215
1216 ret = wait_for_completion_timeout(&channel->open_ack, 5 * HZ);
1217 if (!ret) {
1218 ret = -ETIMEDOUT;
1219 goto close_link;
1220 }
1221
1222 return 0;
1223
1224close_link:
1225 /*
1226 * Send a close request to "undo" our open-ack. The close-ack will
1227 * release qcom_glink_send_open_req() reference and the last reference
1228 * will be relesed after receiving remote_close or transport unregister
1229 * by calling qcom_glink_native_remove().
1230 */
1231 qcom_glink_send_close_req(glink, channel);
1232
1233 return ret;
1234}
1235
1236static struct rpmsg_endpoint *qcom_glink_create_ept(struct rpmsg_device *rpdev,
1237 rpmsg_rx_cb_t cb,
1238 void *priv,
1239 struct rpmsg_channel_info
1240 chinfo)
1241{
1242 struct glink_channel *parent = to_glink_channel(rpdev->ept);
1243 struct glink_channel *channel;
1244 struct qcom_glink *glink = parent->glink;
1245 struct rpmsg_endpoint *ept;
1246 const char *name = chinfo.name;
1247 int cid;
1248 int ret;
1249 unsigned long flags;
1250
1251 spin_lock_irqsave(&glink->idr_lock, flags);
1252 idr_for_each_entry(&glink->rcids, channel, cid) {
1253 if (!strcmp(channel->name, name))
1254 break;
1255 }
1256 spin_unlock_irqrestore(&glink->idr_lock, flags);
1257
1258 if (!channel) {
1259 channel = qcom_glink_create_local(glink, name);
1260 if (IS_ERR(channel))
1261 return NULL;
1262 } else {
1263 ret = qcom_glink_create_remote(glink, channel);
1264 if (ret)
1265 return NULL;
1266 }
1267
1268 ept = &channel->ept;
1269 ept->rpdev = rpdev;
1270 ept->cb = cb;
1271 ept->priv = priv;
1272 ept->ops = &glink_endpoint_ops;
1273
1274 return ept;
1275}
1276
1277static int qcom_glink_announce_create(struct rpmsg_device *rpdev)
1278{
1279 struct glink_channel *channel = to_glink_channel(rpdev->ept);
1280 struct device_node *np = rpdev->dev.of_node;
1281 struct qcom_glink *glink = channel->glink;
1282 struct glink_core_rx_intent *intent;
1283 const struct property *prop = NULL;
1284 __be32 defaults[] = { cpu_to_be32(SZ_1K), cpu_to_be32(5) };
1285 int num_intents;
1286 int num_groups = 1;
1287 __be32 *val = defaults;
1288 int size;
1289
1290 if (glink->intentless || !completion_done(&channel->open_ack))
1291 return 0;
1292
1293 prop = of_find_property(np, "qcom,intents", NULL);
1294 if (prop) {
1295 val = prop->value;
1296 num_groups = prop->length / sizeof(u32) / 2;
1297 }
1298
1299 /* Channel is now open, advertise base set of intents */
1300 while (num_groups--) {
1301 size = be32_to_cpup(val++);
1302 num_intents = be32_to_cpup(val++);
1303 while (num_intents--) {
1304 intent = qcom_glink_alloc_intent(glink, channel, size,
1305 true);
1306 if (!intent)
1307 break;
1308
1309 qcom_glink_advertise_intent(glink, channel, intent);
1310 }
1311 }
1312 return 0;
1313}
1314
1315static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
1316{
1317 struct glink_channel *channel = to_glink_channel(ept);
1318 struct qcom_glink *glink = channel->glink;
1319 unsigned long flags;
1320
1321 spin_lock_irqsave(&channel->recv_lock, flags);
1322 channel->ept.cb = NULL;
1323 spin_unlock_irqrestore(&channel->recv_lock, flags);
1324
1325 /* Decouple the potential rpdev from the channel */
1326 channel->rpdev = NULL;
1327
1328 qcom_glink_send_close_req(glink, channel);
1329}
1330
1331static int qcom_glink_request_intent(struct qcom_glink *glink,
1332 struct glink_channel *channel,
1333 size_t size)
1334{
1335 struct {
1336 u16 id;
1337 u16 cid;
1338 u32 size;
1339 } __packed cmd;
1340
1341 int ret;
1342
1343 mutex_lock(&channel->intent_req_lock);
1344
1345 WRITE_ONCE(channel->intent_req_result, -1);
1346 WRITE_ONCE(channel->intent_received, false);
1347
1348 cmd.id = GLINK_CMD_RX_INTENT_REQ;
1349 cmd.cid = channel->lcid;
1350 cmd.size = size;
1351
1352 ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
1353 if (ret)
1354 goto unlock;
1355
1356 ret = wait_event_timeout(channel->intent_req_wq,
1357 READ_ONCE(channel->intent_req_result) >= 0 &&
1358 READ_ONCE(channel->intent_received),
1359 10 * HZ);
1360 if (!ret) {
1361 dev_err(glink->dev, "intent request timed out\n");
1362 ret = -ETIMEDOUT;
1363 } else {
1364 ret = READ_ONCE(channel->intent_req_result) ? 0 : -ECANCELED;
1365 }
1366
1367unlock:
1368 mutex_unlock(&channel->intent_req_lock);
1369 return ret;
1370}
1371
1372static int __qcom_glink_send(struct glink_channel *channel,
1373 void *data, int len, bool wait)
1374{
1375 struct qcom_glink *glink = channel->glink;
1376 struct glink_core_rx_intent *intent = NULL;
1377 struct glink_core_rx_intent *tmp;
1378 int iid = 0;
1379 struct {
1380 struct glink_msg msg;
1381 __le32 chunk_size;
1382 __le32 left_size;
1383 } __packed req;
1384 int ret;
1385 unsigned long flags;
1386 int chunk_size = len;
1387 size_t offset = 0;
1388
1389 if (!glink->intentless) {
1390 while (!intent) {
1391 spin_lock_irqsave(&channel->intent_lock, flags);
1392 idr_for_each_entry(&channel->riids, tmp, iid) {
1393 if (tmp->size >= len && !tmp->in_use) {
1394 if (!intent)
1395 intent = tmp;
1396 else if (intent->size > tmp->size)
1397 intent = tmp;
1398 if (intent->size == len)
1399 break;
1400 }
1401 }
1402 if (intent)
1403 intent->in_use = true;
1404 spin_unlock_irqrestore(&channel->intent_lock, flags);
1405
1406 /* We found an available intent */
1407 if (intent)
1408 break;
1409
1410 if (!wait)
1411 return -EBUSY;
1412
1413 ret = qcom_glink_request_intent(glink, channel, len);
1414 if (ret < 0)
1415 return ret;
1416 }
1417
1418 iid = intent->id;
1419 }
1420
1421 while (offset < len) {
1422 chunk_size = len - offset;
1423 if (chunk_size > SZ_8K && wait)
1424 chunk_size = SZ_8K;
1425
1426 req.msg.cmd = cpu_to_le16(offset == 0 ? GLINK_CMD_TX_DATA : GLINK_CMD_TX_DATA_CONT);
1427 req.msg.param1 = cpu_to_le16(channel->lcid);
1428 req.msg.param2 = cpu_to_le32(iid);
1429 req.chunk_size = cpu_to_le32(chunk_size);
1430 req.left_size = cpu_to_le32(len - offset - chunk_size);
1431
1432 ret = qcom_glink_tx(glink, &req, sizeof(req), data + offset, chunk_size, wait);
1433 if (ret) {
1434 /* Mark intent available if we failed */
1435 if (intent)
1436 intent->in_use = false;
1437 return ret;
1438 }
1439
1440 offset += chunk_size;
1441 }
1442
1443 return 0;
1444}
1445
1446static int qcom_glink_send(struct rpmsg_endpoint *ept, void *data, int len)
1447{
1448 struct glink_channel *channel = to_glink_channel(ept);
1449
1450 return __qcom_glink_send(channel, data, len, true);
1451}
1452
1453static int qcom_glink_trysend(struct rpmsg_endpoint *ept, void *data, int len)
1454{
1455 struct glink_channel *channel = to_glink_channel(ept);
1456
1457 return __qcom_glink_send(channel, data, len, false);
1458}
1459
1460static int qcom_glink_sendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1461{
1462 struct glink_channel *channel = to_glink_channel(ept);
1463
1464 return __qcom_glink_send(channel, data, len, true);
1465}
1466
1467static int qcom_glink_trysendto(struct rpmsg_endpoint *ept, void *data, int len, u32 dst)
1468{
1469 struct glink_channel *channel = to_glink_channel(ept);
1470
1471 return __qcom_glink_send(channel, data, len, false);
1472}
1473
1474/*
1475 * Finds the device_node for the glink child interested in this channel.
1476 */
1477static struct device_node *qcom_glink_match_channel(struct device_node *node,
1478 const char *channel)
1479{
1480 struct device_node *child;
1481 const char *name;
1482 const char *key;
1483 int ret;
1484
1485 for_each_available_child_of_node(node, child) {
1486 key = "qcom,glink-channels";
1487 ret = of_property_read_string(child, key, &name);
1488 if (ret)
1489 continue;
1490
1491 if (strcmp(name, channel) == 0)
1492 return child;
1493 }
1494
1495 return NULL;
1496}
1497
1498static const struct rpmsg_device_ops glink_device_ops = {
1499 .create_ept = qcom_glink_create_ept,
1500 .announce_create = qcom_glink_announce_create,
1501};
1502
1503static const struct rpmsg_endpoint_ops glink_endpoint_ops = {
1504 .destroy_ept = qcom_glink_destroy_ept,
1505 .send = qcom_glink_send,
1506 .sendto = qcom_glink_sendto,
1507 .trysend = qcom_glink_trysend,
1508 .trysendto = qcom_glink_trysendto,
1509 .set_flow_control = qcom_glink_set_flow_control,
1510};
1511
1512static void qcom_glink_rpdev_release(struct device *dev)
1513{
1514 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1515
1516 kfree(rpdev->driver_override);
1517 kfree(rpdev);
1518}
1519
1520static int qcom_glink_rx_open(struct qcom_glink *glink, unsigned int rcid,
1521 char *name)
1522{
1523 struct glink_channel *channel;
1524 struct rpmsg_device *rpdev;
1525 bool create_device = false;
1526 struct device_node *node;
1527 int lcid;
1528 int ret;
1529 unsigned long flags;
1530
1531 spin_lock_irqsave(&glink->idr_lock, flags);
1532 idr_for_each_entry(&glink->lcids, channel, lcid) {
1533 if (!strcmp(channel->name, name))
1534 break;
1535 }
1536 spin_unlock_irqrestore(&glink->idr_lock, flags);
1537
1538 if (!channel) {
1539 channel = qcom_glink_alloc_channel(glink, name);
1540 if (IS_ERR(channel))
1541 return PTR_ERR(channel);
1542
1543 /* The opening dance was initiated by the remote */
1544 create_device = true;
1545 }
1546
1547 spin_lock_irqsave(&glink->idr_lock, flags);
1548 ret = idr_alloc(&glink->rcids, channel, rcid, rcid + 1, GFP_ATOMIC);
1549 if (ret < 0) {
1550 dev_err(glink->dev, "Unable to insert channel into rcid list\n");
1551 spin_unlock_irqrestore(&glink->idr_lock, flags);
1552 goto free_channel;
1553 }
1554 channel->rcid = ret;
1555 spin_unlock_irqrestore(&glink->idr_lock, flags);
1556
1557 complete_all(&channel->open_req);
1558
1559 if (create_device) {
1560 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1561 if (!rpdev) {
1562 ret = -ENOMEM;
1563 goto rcid_remove;
1564 }
1565
1566 rpdev->ept = &channel->ept;
1567 strscpy_pad(rpdev->id.name, name, RPMSG_NAME_SIZE);
1568 rpdev->src = RPMSG_ADDR_ANY;
1569 rpdev->dst = RPMSG_ADDR_ANY;
1570 rpdev->ops = &glink_device_ops;
1571
1572 node = qcom_glink_match_channel(glink->dev->of_node, name);
1573 rpdev->dev.of_node = node;
1574 rpdev->dev.parent = glink->dev;
1575 rpdev->dev.release = qcom_glink_rpdev_release;
1576
1577 ret = rpmsg_register_device(rpdev);
1578 if (ret)
1579 goto rcid_remove;
1580
1581 channel->rpdev = rpdev;
1582 }
1583
1584 return 0;
1585
1586rcid_remove:
1587 spin_lock_irqsave(&glink->idr_lock, flags);
1588 idr_remove(&glink->rcids, channel->rcid);
1589 channel->rcid = 0;
1590 spin_unlock_irqrestore(&glink->idr_lock, flags);
1591free_channel:
1592 /* Release the reference, iff we took it */
1593 if (create_device)
1594 kref_put(&channel->refcount, qcom_glink_channel_release);
1595
1596 return ret;
1597}
1598
1599static void qcom_glink_rx_close(struct qcom_glink *glink, unsigned int rcid)
1600{
1601 struct rpmsg_channel_info chinfo;
1602 struct glink_channel *channel;
1603 unsigned long flags;
1604
1605 spin_lock_irqsave(&glink->idr_lock, flags);
1606 channel = idr_find(&glink->rcids, rcid);
1607 spin_unlock_irqrestore(&glink->idr_lock, flags);
1608 if (WARN(!channel, "close request on unknown channel\n"))
1609 return;
1610
1611 /* cancel pending rx_done work */
1612 cancel_work_sync(&channel->intent_work);
1613
1614 if (channel->rpdev) {
1615 strscpy_pad(chinfo.name, channel->name, sizeof(chinfo.name));
1616 chinfo.src = RPMSG_ADDR_ANY;
1617 chinfo.dst = RPMSG_ADDR_ANY;
1618
1619 rpmsg_unregister_device(glink->dev, &chinfo);
1620 }
1621 channel->rpdev = NULL;
1622
1623 qcom_glink_send_close_ack(glink, channel->rcid);
1624
1625 spin_lock_irqsave(&glink->idr_lock, flags);
1626 idr_remove(&glink->rcids, channel->rcid);
1627 channel->rcid = 0;
1628 spin_unlock_irqrestore(&glink->idr_lock, flags);
1629
1630 kref_put(&channel->refcount, qcom_glink_channel_release);
1631}
1632
1633static void qcom_glink_rx_close_ack(struct qcom_glink *glink, unsigned int lcid)
1634{
1635 struct rpmsg_channel_info chinfo;
1636 struct glink_channel *channel;
1637 unsigned long flags;
1638
1639 /* To wakeup any blocking writers */
1640 wake_up_all(&glink->tx_avail_notify);
1641
1642 spin_lock_irqsave(&glink->idr_lock, flags);
1643 channel = idr_find(&glink->lcids, lcid);
1644 if (WARN(!channel, "close ack on unknown channel\n")) {
1645 spin_unlock_irqrestore(&glink->idr_lock, flags);
1646 return;
1647 }
1648
1649 idr_remove(&glink->lcids, channel->lcid);
1650 channel->lcid = 0;
1651 spin_unlock_irqrestore(&glink->idr_lock, flags);
1652
1653 /* Decouple the potential rpdev from the channel */
1654 if (channel->rpdev) {
1655 strscpy(chinfo.name, channel->name, sizeof(chinfo.name));
1656 chinfo.src = RPMSG_ADDR_ANY;
1657 chinfo.dst = RPMSG_ADDR_ANY;
1658
1659 rpmsg_unregister_device(glink->dev, &chinfo);
1660 }
1661 channel->rpdev = NULL;
1662
1663 kref_put(&channel->refcount, qcom_glink_channel_release);
1664}
1665
1666static void qcom_glink_work(struct work_struct *work)
1667{
1668 struct qcom_glink *glink = container_of(work, struct qcom_glink,
1669 rx_work);
1670 struct glink_defer_cmd *dcmd;
1671 struct glink_msg *msg;
1672 unsigned long flags;
1673 unsigned int param1;
1674 unsigned int param2;
1675 unsigned int cmd;
1676
1677 for (;;) {
1678 spin_lock_irqsave(&glink->rx_lock, flags);
1679 if (list_empty(&glink->rx_queue)) {
1680 spin_unlock_irqrestore(&glink->rx_lock, flags);
1681 break;
1682 }
1683 dcmd = list_first_entry(&glink->rx_queue,
1684 struct glink_defer_cmd, node);
1685 list_del(&dcmd->node);
1686 spin_unlock_irqrestore(&glink->rx_lock, flags);
1687
1688 msg = &dcmd->msg;
1689 cmd = le16_to_cpu(msg->cmd);
1690 param1 = le16_to_cpu(msg->param1);
1691 param2 = le32_to_cpu(msg->param2);
1692
1693 switch (cmd) {
1694 case GLINK_CMD_VERSION:
1695 qcom_glink_receive_version(glink, param1, param2);
1696 break;
1697 case GLINK_CMD_VERSION_ACK:
1698 qcom_glink_receive_version_ack(glink, param1, param2);
1699 break;
1700 case GLINK_CMD_OPEN:
1701 qcom_glink_rx_open(glink, param1, msg->data);
1702 break;
1703 case GLINK_CMD_CLOSE:
1704 qcom_glink_rx_close(glink, param1);
1705 break;
1706 case GLINK_CMD_CLOSE_ACK:
1707 qcom_glink_rx_close_ack(glink, param1);
1708 break;
1709 case GLINK_CMD_RX_INTENT_REQ:
1710 qcom_glink_handle_intent_req(glink, param1, param2);
1711 break;
1712 default:
1713 WARN(1, "Unknown defer object %d\n", cmd);
1714 break;
1715 }
1716
1717 kfree(dcmd);
1718 }
1719}
1720
1721static void qcom_glink_cancel_rx_work(struct qcom_glink *glink)
1722{
1723 struct glink_defer_cmd *dcmd;
1724 struct glink_defer_cmd *tmp;
1725
1726 /* cancel any pending deferred rx_work */
1727 cancel_work_sync(&glink->rx_work);
1728
1729 list_for_each_entry_safe(dcmd, tmp, &glink->rx_queue, node)
1730 kfree(dcmd);
1731}
1732
1733static ssize_t rpmsg_name_show(struct device *dev,
1734 struct device_attribute *attr, char *buf)
1735{
1736 int ret = 0;
1737 const char *name;
1738
1739 ret = of_property_read_string(dev->of_node, "label", &name);
1740 if (ret < 0)
1741 name = dev->of_node->name;
1742
1743 return sysfs_emit(buf, "%s\n", name);
1744}
1745static DEVICE_ATTR_RO(rpmsg_name);
1746
1747static struct attribute *qcom_glink_attrs[] = {
1748 &dev_attr_rpmsg_name.attr,
1749 NULL
1750};
1751ATTRIBUTE_GROUPS(qcom_glink);
1752
1753static void qcom_glink_device_release(struct device *dev)
1754{
1755 struct rpmsg_device *rpdev = to_rpmsg_device(dev);
1756 struct glink_channel *channel = to_glink_channel(rpdev->ept);
1757
1758 /* Release qcom_glink_alloc_channel() reference */
1759 kref_put(&channel->refcount, qcom_glink_channel_release);
1760 kfree(rpdev->driver_override);
1761 kfree(rpdev);
1762}
1763
1764static int qcom_glink_create_chrdev(struct qcom_glink *glink)
1765{
1766 struct rpmsg_device *rpdev;
1767 struct glink_channel *channel;
1768
1769 rpdev = kzalloc(sizeof(*rpdev), GFP_KERNEL);
1770 if (!rpdev)
1771 return -ENOMEM;
1772
1773 channel = qcom_glink_alloc_channel(glink, "rpmsg_chrdev");
1774 if (IS_ERR(channel)) {
1775 kfree(rpdev);
1776 return PTR_ERR(channel);
1777 }
1778 channel->rpdev = rpdev;
1779
1780 rpdev->ept = &channel->ept;
1781 rpdev->ops = &glink_device_ops;
1782 rpdev->dev.parent = glink->dev;
1783 rpdev->dev.release = qcom_glink_device_release;
1784
1785 return rpmsg_ctrldev_register_device(rpdev);
1786}
1787
1788struct qcom_glink *qcom_glink_native_probe(struct device *dev,
1789 unsigned long features,
1790 struct qcom_glink_pipe *rx,
1791 struct qcom_glink_pipe *tx,
1792 bool intentless)
1793{
1794 int ret;
1795 struct qcom_glink *glink;
1796
1797 glink = devm_kzalloc(dev, sizeof(*glink), GFP_KERNEL);
1798 if (!glink)
1799 return ERR_PTR(-ENOMEM);
1800
1801 glink->dev = dev;
1802 glink->tx_pipe = tx;
1803 glink->rx_pipe = rx;
1804
1805 glink->features = features;
1806 glink->intentless = intentless;
1807
1808 spin_lock_init(&glink->tx_lock);
1809 spin_lock_init(&glink->rx_lock);
1810 INIT_LIST_HEAD(&glink->rx_queue);
1811 INIT_WORK(&glink->rx_work, qcom_glink_work);
1812 init_waitqueue_head(&glink->tx_avail_notify);
1813
1814 spin_lock_init(&glink->idr_lock);
1815 idr_init(&glink->lcids);
1816 idr_init(&glink->rcids);
1817
1818 glink->dev->groups = qcom_glink_groups;
1819
1820 ret = device_add_groups(dev, qcom_glink_groups);
1821 if (ret)
1822 dev_err(dev, "failed to add groups\n");
1823
1824 ret = qcom_glink_send_version(glink);
1825 if (ret)
1826 return ERR_PTR(ret);
1827
1828 ret = qcom_glink_create_chrdev(glink);
1829 if (ret)
1830 dev_err(glink->dev, "failed to register chrdev\n");
1831
1832 return glink;
1833}
1834EXPORT_SYMBOL_GPL(qcom_glink_native_probe);
1835
1836static int qcom_glink_remove_device(struct device *dev, void *data)
1837{
1838 device_unregister(dev);
1839
1840 return 0;
1841}
1842
1843void qcom_glink_native_remove(struct qcom_glink *glink)
1844{
1845 struct glink_channel *channel;
1846 unsigned long flags;
1847 int cid;
1848 int ret;
1849
1850 qcom_glink_cancel_rx_work(glink);
1851
1852 /* Fail all attempts at sending messages */
1853 spin_lock_irqsave(&glink->tx_lock, flags);
1854 glink->abort_tx = true;
1855 wake_up_all(&glink->tx_avail_notify);
1856 spin_unlock_irqrestore(&glink->tx_lock, flags);
1857
1858 /* Abort any senders waiting for intent requests */
1859 spin_lock_irqsave(&glink->idr_lock, flags);
1860 idr_for_each_entry(&glink->lcids, channel, cid)
1861 qcom_glink_intent_req_abort(channel);
1862 spin_unlock_irqrestore(&glink->idr_lock, flags);
1863
1864 ret = device_for_each_child(glink->dev, NULL, qcom_glink_remove_device);
1865 if (ret)
1866 dev_warn(glink->dev, "Can't remove GLINK devices: %d\n", ret);
1867
1868 /* Release any defunct local channels, waiting for close-ack */
1869 idr_for_each_entry(&glink->lcids, channel, cid)
1870 kref_put(&channel->refcount, qcom_glink_channel_release);
1871
1872 /* Release any defunct local channels, waiting for close-req */
1873 idr_for_each_entry(&glink->rcids, channel, cid)
1874 kref_put(&channel->refcount, qcom_glink_channel_release);
1875
1876 idr_destroy(&glink->lcids);
1877 idr_destroy(&glink->rcids);
1878}
1879EXPORT_SYMBOL_GPL(qcom_glink_native_remove);
1880
1881MODULE_DESCRIPTION("Qualcomm GLINK driver");
1882MODULE_LICENSE("GPL v2");