blob: 06fef2b4c81408f3e4e1bb1c91949f82e6afa58b [file] [log] [blame]
Bjorn Andersson53e28222016-09-01 15:28:09 -07001/*
2 * Copyright (c) 2015, Sony Mobile Communications AB.
3 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 and
7 * only version 2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include <linux/interrupt.h>
16#include <linux/io.h>
17#include <linux/mfd/syscon.h>
18#include <linux/module.h>
19#include <linux/of_irq.h>
20#include <linux/of_platform.h>
21#include <linux/platform_device.h>
22#include <linux/regmap.h>
23#include <linux/sched.h>
24#include <linux/slab.h>
25#include <linux/soc/qcom/smem.h>
26#include <linux/wait.h>
27#include <linux/rpmsg.h>
28
29#include "rpmsg_internal.h"
30
31/*
32 * The Qualcomm Shared Memory communication solution provides point-to-point
33 * channels for clients to send and receive streaming or packet based data.
34 *
35 * Each channel consists of a control item (channel info) and a ring buffer
36 * pair. The channel info carry information related to channel state, flow
37 * control and the offsets within the ring buffer.
38 *
39 * All allocated channels are listed in an allocation table, identifying the
40 * pair of items by name, type and remote processor.
41 *
42 * Upon creating a new channel the remote processor allocates channel info and
43 * ring buffer items from the smem heap and populate the allocation table. An
44 * interrupt is sent to the other end of the channel and a scan for new
45 * channels should be done. A channel never goes away, it will only change
46 * state.
47 *
48 * The remote processor signals it intent for bring up the communication
49 * channel by setting the state of its end of the channel to "opening" and
50 * sends out an interrupt. We detect this change and register a smd device to
51 * consume the channel. Upon finding a consumer we finish the handshake and the
52 * channel is up.
53 *
54 * Upon closing a channel, the remote processor will update the state of its
55 * end of the channel and signal us, we will then unregister any attached
56 * device and close our end of the channel.
57 *
58 * Devices attached to a channel can use the qcom_smd_send function to push
59 * data to the channel, this is done by copying the data into the tx ring
60 * buffer, updating the pointers in the channel info and signaling the remote
61 * processor.
62 *
63 * The remote processor does the equivalent when it transfer data and upon
64 * receiving the interrupt we check the channel info for new data and delivers
65 * this to the attached device. If the device is not ready to receive the data
66 * we leave it in the ring buffer for now.
67 */
68
69struct smd_channel_info;
70struct smd_channel_info_pair;
71struct smd_channel_info_word;
72struct smd_channel_info_word_pair;
73
74static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops;
75
76#define SMD_ALLOC_TBL_COUNT 2
77#define SMD_ALLOC_TBL_SIZE 64
78
79/*
80 * This lists the various smem heap items relevant for the allocation table and
81 * smd channel entries.
82 */
83static const struct {
84 unsigned alloc_tbl_id;
85 unsigned info_base_id;
86 unsigned fifo_base_id;
87} smem_items[SMD_ALLOC_TBL_COUNT] = {
88 {
89 .alloc_tbl_id = 13,
90 .info_base_id = 14,
91 .fifo_base_id = 338
92 },
93 {
94 .alloc_tbl_id = 266,
95 .info_base_id = 138,
96 .fifo_base_id = 202,
97 },
98};
99
100/**
101 * struct qcom_smd_edge - representing a remote processor
102 * @of_node: of_node handle for information related to this edge
103 * @edge_id: identifier of this edge
104 * @remote_pid: identifier of remote processor
105 * @irq: interrupt for signals on this edge
106 * @ipc_regmap: regmap handle holding the outgoing ipc register
107 * @ipc_offset: offset within @ipc_regmap of the register for ipc
108 * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap
109 * @channels: list of all channels detected on this edge
110 * @channels_lock: guard for modifications of @channels
111 * @allocated: array of bitmaps representing already allocated channels
112 * @smem_available: last available amount of smem triggering a channel scan
113 * @scan_work: work item for discovering new channels
114 * @state_work: work item for edge state changes
115 */
116struct qcom_smd_edge {
117 struct device dev;
118
119 struct device_node *of_node;
120 unsigned edge_id;
121 unsigned remote_pid;
122
123 int irq;
124
125 struct regmap *ipc_regmap;
126 int ipc_offset;
127 int ipc_bit;
128
129 struct list_head channels;
130 spinlock_t channels_lock;
131
132 DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
133
134 unsigned smem_available;
135
136 wait_queue_head_t new_channel_event;
137
138 struct work_struct scan_work;
139 struct work_struct state_work;
140};
141
142/*
143 * SMD channel states.
144 */
145enum smd_channel_state {
146 SMD_CHANNEL_CLOSED,
147 SMD_CHANNEL_OPENING,
148 SMD_CHANNEL_OPENED,
149 SMD_CHANNEL_FLUSHING,
150 SMD_CHANNEL_CLOSING,
151 SMD_CHANNEL_RESET,
152 SMD_CHANNEL_RESET_OPENING
153};
154
155struct qcom_smd_device {
156 struct rpmsg_device rpdev;
157
158 struct qcom_smd_edge *edge;
159};
160
161struct qcom_smd_endpoint {
162 struct rpmsg_endpoint ept;
163
164 struct qcom_smd_channel *qsch;
165};
166
167#define to_smd_device(_rpdev) container_of(_rpdev, struct qcom_smd_device, rpdev)
168#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev)
169#define to_smd_endpoint(ept) container_of(ept, struct qcom_smd_endpoint, ept)
170
171/**
172 * struct qcom_smd_channel - smd channel struct
173 * @edge: qcom_smd_edge this channel is living on
174 * @qsdev: reference to a associated smd client device
175 * @name: name of the channel
176 * @state: local state of the channel
177 * @remote_state: remote state of the channel
178 * @info: byte aligned outgoing/incoming channel info
179 * @info_word: word aligned outgoing/incoming channel info
180 * @tx_lock: lock to make writes to the channel mutually exclusive
181 * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR
182 * @tx_fifo: pointer to the outgoing ring buffer
183 * @rx_fifo: pointer to the incoming ring buffer
184 * @fifo_size: size of each ring buffer
185 * @bounce_buffer: bounce buffer for reading wrapped packets
186 * @cb: callback function registered for this channel
187 * @recv_lock: guard for rx info modifications and cb pointer
188 * @pkt_size: size of the currently handled packet
189 * @list: lite entry for @channels in qcom_smd_edge
190 */
191struct qcom_smd_channel {
192 struct qcom_smd_edge *edge;
193
194 struct qcom_smd_endpoint *qsept;
195 bool registered;
196
197 char *name;
198 enum smd_channel_state state;
199 enum smd_channel_state remote_state;
200
201 struct smd_channel_info_pair *info;
202 struct smd_channel_info_word_pair *info_word;
203
204 struct mutex tx_lock;
205 wait_queue_head_t fblockread_event;
206
207 void *tx_fifo;
208 void *rx_fifo;
209 int fifo_size;
210
211 void *bounce_buffer;
212
213 spinlock_t recv_lock;
214
215 int pkt_size;
216
217 void *drvdata;
218
219 struct list_head list;
220};
221
222/*
223 * Format of the smd_info smem items, for byte aligned channels.
224 */
225struct smd_channel_info {
226 __le32 state;
227 u8 fDSR;
228 u8 fCTS;
229 u8 fCD;
230 u8 fRI;
231 u8 fHEAD;
232 u8 fTAIL;
233 u8 fSTATE;
234 u8 fBLOCKREADINTR;
235 __le32 tail;
236 __le32 head;
237};
238
239struct smd_channel_info_pair {
240 struct smd_channel_info tx;
241 struct smd_channel_info rx;
242};
243
244/*
245 * Format of the smd_info smem items, for word aligned channels.
246 */
247struct smd_channel_info_word {
248 __le32 state;
249 __le32 fDSR;
250 __le32 fCTS;
251 __le32 fCD;
252 __le32 fRI;
253 __le32 fHEAD;
254 __le32 fTAIL;
255 __le32 fSTATE;
256 __le32 fBLOCKREADINTR;
257 __le32 tail;
258 __le32 head;
259};
260
261struct smd_channel_info_word_pair {
262 struct smd_channel_info_word tx;
263 struct smd_channel_info_word rx;
264};
265
266#define GET_RX_CHANNEL_FLAG(channel, param) \
267 ({ \
268 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
269 channel->info_word ? \
270 le32_to_cpu(channel->info_word->rx.param) : \
271 channel->info->rx.param; \
272 })
273
274#define GET_RX_CHANNEL_INFO(channel, param) \
275 ({ \
276 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
277 le32_to_cpu(channel->info_word ? \
278 channel->info_word->rx.param : \
279 channel->info->rx.param); \
280 })
281
282#define SET_RX_CHANNEL_FLAG(channel, param, value) \
283 ({ \
284 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \
285 if (channel->info_word) \
286 channel->info_word->rx.param = cpu_to_le32(value); \
287 else \
288 channel->info->rx.param = value; \
289 })
290
291#define SET_RX_CHANNEL_INFO(channel, param, value) \
292 ({ \
293 BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \
294 if (channel->info_word) \
295 channel->info_word->rx.param = cpu_to_le32(value); \
296 else \
297 channel->info->rx.param = cpu_to_le32(value); \
298 })
299
300#define GET_TX_CHANNEL_FLAG(channel, param) \
301 ({ \
302 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
303 channel->info_word ? \
304 le32_to_cpu(channel->info_word->tx.param) : \
305 channel->info->tx.param; \
306 })
307
308#define GET_TX_CHANNEL_INFO(channel, param) \
309 ({ \
310 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
311 le32_to_cpu(channel->info_word ? \
312 channel->info_word->tx.param : \
313 channel->info->tx.param); \
314 })
315
316#define SET_TX_CHANNEL_FLAG(channel, param, value) \
317 ({ \
318 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \
319 if (channel->info_word) \
320 channel->info_word->tx.param = cpu_to_le32(value); \
321 else \
322 channel->info->tx.param = value; \
323 })
324
325#define SET_TX_CHANNEL_INFO(channel, param, value) \
326 ({ \
327 BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \
328 if (channel->info_word) \
329 channel->info_word->tx.param = cpu_to_le32(value); \
330 else \
331 channel->info->tx.param = cpu_to_le32(value); \
332 })
333
334/**
335 * struct qcom_smd_alloc_entry - channel allocation entry
336 * @name: channel name
337 * @cid: channel index
338 * @flags: channel flags and edge id
339 * @ref_count: reference count of the channel
340 */
341struct qcom_smd_alloc_entry {
342 u8 name[20];
343 __le32 cid;
344 __le32 flags;
345 __le32 ref_count;
346} __packed;
347
348#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff
349#define SMD_CHANNEL_FLAGS_STREAM BIT(8)
350#define SMD_CHANNEL_FLAGS_PACKET BIT(9)
351
352/*
353 * Each smd packet contains a 20 byte header, with the first 4 being the length
354 * of the packet.
355 */
356#define SMD_PACKET_HEADER_LEN 20
357
358/*
359 * Signal the remote processor associated with 'channel'.
360 */
361static void qcom_smd_signal_channel(struct qcom_smd_channel *channel)
362{
363 struct qcom_smd_edge *edge = channel->edge;
364
365 regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit));
366}
367
368/*
369 * Initialize the tx channel info
370 */
371static void qcom_smd_channel_reset(struct qcom_smd_channel *channel)
372{
373 SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
374 SET_TX_CHANNEL_FLAG(channel, fDSR, 0);
375 SET_TX_CHANNEL_FLAG(channel, fCTS, 0);
376 SET_TX_CHANNEL_FLAG(channel, fCD, 0);
377 SET_TX_CHANNEL_FLAG(channel, fRI, 0);
378 SET_TX_CHANNEL_FLAG(channel, fHEAD, 0);
379 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
380 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
381 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
382 SET_TX_CHANNEL_INFO(channel, head, 0);
383 SET_RX_CHANNEL_INFO(channel, tail, 0);
384
385 qcom_smd_signal_channel(channel);
386
387 channel->state = SMD_CHANNEL_CLOSED;
388 channel->pkt_size = 0;
389}
390
391/*
392 * Set the callback for a channel, with appropriate locking
393 */
394static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
395 rpmsg_rx_cb_t cb)
396{
397 struct rpmsg_endpoint *ept = &channel->qsept->ept;
398 unsigned long flags;
399
400 spin_lock_irqsave(&channel->recv_lock, flags);
401 ept->cb = cb;
402 spin_unlock_irqrestore(&channel->recv_lock, flags);
403};
404
405/*
406 * Calculate the amount of data available in the rx fifo
407 */
408static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel)
409{
410 unsigned head;
411 unsigned tail;
412
413 head = GET_RX_CHANNEL_INFO(channel, head);
414 tail = GET_RX_CHANNEL_INFO(channel, tail);
415
416 return (head - tail) & (channel->fifo_size - 1);
417}
418
419/*
420 * Set tx channel state and inform the remote processor
421 */
422static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel,
423 int state)
424{
425 struct qcom_smd_edge *edge = channel->edge;
426 bool is_open = state == SMD_CHANNEL_OPENED;
427
428 if (channel->state == state)
429 return;
430
431 dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state);
432
433 SET_TX_CHANNEL_FLAG(channel, fDSR, is_open);
434 SET_TX_CHANNEL_FLAG(channel, fCTS, is_open);
435 SET_TX_CHANNEL_FLAG(channel, fCD, is_open);
436
437 SET_TX_CHANNEL_INFO(channel, state, state);
438 SET_TX_CHANNEL_FLAG(channel, fSTATE, 1);
439
440 channel->state = state;
441 qcom_smd_signal_channel(channel);
442}
443
444/*
445 * Copy count bytes of data using 32bit accesses, if that's required.
446 */
447static void smd_copy_to_fifo(void __iomem *dst,
448 const void *src,
449 size_t count,
450 bool word_aligned)
451{
452 if (word_aligned) {
453 __iowrite32_copy(dst, src, count / sizeof(u32));
454 } else {
455 memcpy_toio(dst, src, count);
456 }
457}
458
459/*
460 * Copy count bytes of data using 32bit accesses, if that is required.
461 */
462static void smd_copy_from_fifo(void *dst,
463 const void __iomem *src,
464 size_t count,
465 bool word_aligned)
466{
467 if (word_aligned) {
468 __ioread32_copy(dst, src, count / sizeof(u32));
469 } else {
470 memcpy_fromio(dst, src, count);
471 }
472}
473
474/*
475 * Read count bytes of data from the rx fifo into buf, but don't advance the
476 * tail.
477 */
478static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel,
479 void *buf, size_t count)
480{
481 bool word_aligned;
482 unsigned tail;
483 size_t len;
484
485 word_aligned = channel->info_word;
486 tail = GET_RX_CHANNEL_INFO(channel, tail);
487
488 len = min_t(size_t, count, channel->fifo_size - tail);
489 if (len) {
490 smd_copy_from_fifo(buf,
491 channel->rx_fifo + tail,
492 len,
493 word_aligned);
494 }
495
496 if (len != count) {
497 smd_copy_from_fifo(buf + len,
498 channel->rx_fifo,
499 count - len,
500 word_aligned);
501 }
502
503 return count;
504}
505
506/*
507 * Advance the rx tail by count bytes.
508 */
509static void qcom_smd_channel_advance(struct qcom_smd_channel *channel,
510 size_t count)
511{
512 unsigned tail;
513
514 tail = GET_RX_CHANNEL_INFO(channel, tail);
515 tail += count;
516 tail &= (channel->fifo_size - 1);
517 SET_RX_CHANNEL_INFO(channel, tail, tail);
518}
519
520/*
521 * Read out a single packet from the rx fifo and deliver it to the device
522 */
523static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel)
524{
525 struct rpmsg_endpoint *ept = &channel->qsept->ept;
526 unsigned tail;
527 size_t len;
528 void *ptr;
529 int ret;
530
531 tail = GET_RX_CHANNEL_INFO(channel, tail);
532
533 /* Use bounce buffer if the data wraps */
534 if (tail + channel->pkt_size >= channel->fifo_size) {
535 ptr = channel->bounce_buffer;
536 len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size);
537 } else {
538 ptr = channel->rx_fifo + tail;
539 len = channel->pkt_size;
540 }
541
542 ret = ept->cb(ept->rpdev, ptr, len, ept->priv, RPMSG_ADDR_ANY);
543 if (ret < 0)
544 return ret;
545
546 /* Only forward the tail if the client consumed the data */
547 qcom_smd_channel_advance(channel, len);
548
549 channel->pkt_size = 0;
550
551 return 0;
552}
553
554/*
555 * Per channel interrupt handling
556 */
557static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
558{
559 bool need_state_scan = false;
560 int remote_state;
561 __le32 pktlen;
562 int avail;
563 int ret;
564
565 /* Handle state changes */
566 remote_state = GET_RX_CHANNEL_INFO(channel, state);
567 if (remote_state != channel->remote_state) {
568 channel->remote_state = remote_state;
569 need_state_scan = true;
570 }
571 /* Indicate that we have seen any state change */
572 SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
573
574 /* Signal waiting qcom_smd_send() about the interrupt */
575 if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
576 wake_up_interruptible(&channel->fblockread_event);
577
578 /* Don't consume any data until we've opened the channel */
579 if (channel->state != SMD_CHANNEL_OPENED)
580 goto out;
581
582 /* Indicate that we've seen the new data */
583 SET_RX_CHANNEL_FLAG(channel, fHEAD, 0);
584
585 /* Consume data */
586 for (;;) {
587 avail = qcom_smd_channel_get_rx_avail(channel);
588
589 if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) {
590 qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen));
591 qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN);
592 channel->pkt_size = le32_to_cpu(pktlen);
593 } else if (channel->pkt_size && avail >= channel->pkt_size) {
594 ret = qcom_smd_channel_recv_single(channel);
595 if (ret)
596 break;
597 } else {
598 break;
599 }
600 }
601
602 /* Indicate that we have seen and updated tail */
603 SET_RX_CHANNEL_FLAG(channel, fTAIL, 1);
604
605 /* Signal the remote that we've consumed the data (if requested) */
606 if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) {
607 /* Ensure ordering of channel info updates */
608 wmb();
609
610 qcom_smd_signal_channel(channel);
611 }
612
613out:
614 return need_state_scan;
615}
616
617/*
618 * The edge interrupts are triggered by the remote processor on state changes,
619 * channel info updates or when new channels are created.
620 */
621static irqreturn_t qcom_smd_edge_intr(int irq, void *data)
622{
623 struct qcom_smd_edge *edge = data;
624 struct qcom_smd_channel *channel;
625 unsigned available;
626 bool kick_scanner = false;
627 bool kick_state = false;
628
629 /*
630 * Handle state changes or data on each of the channels on this edge
631 */
632 spin_lock(&edge->channels_lock);
633 list_for_each_entry(channel, &edge->channels, list) {
634 spin_lock(&channel->recv_lock);
635 kick_state |= qcom_smd_channel_intr(channel);
636 spin_unlock(&channel->recv_lock);
637 }
638 spin_unlock(&edge->channels_lock);
639
640 /*
641 * Creating a new channel requires allocating an smem entry, so we only
642 * have to scan if the amount of available space in smem have changed
643 * since last scan.
644 */
645 available = qcom_smem_get_free_space(edge->remote_pid);
646 if (available != edge->smem_available) {
647 edge->smem_available = available;
648 kick_scanner = true;
649 }
650
651 if (kick_scanner)
652 schedule_work(&edge->scan_work);
653 if (kick_state)
654 schedule_work(&edge->state_work);
655
656 return IRQ_HANDLED;
657}
658
659/*
660 * Calculate how much space is available in the tx fifo.
661 */
662static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel)
663{
664 unsigned head;
665 unsigned tail;
666 unsigned mask = channel->fifo_size - 1;
667
668 head = GET_TX_CHANNEL_INFO(channel, head);
669 tail = GET_TX_CHANNEL_INFO(channel, tail);
670
671 return mask - ((head - tail) & mask);
672}
673
674/*
675 * Write count bytes of data into channel, possibly wrapping in the ring buffer
676 */
677static int qcom_smd_write_fifo(struct qcom_smd_channel *channel,
678 const void *data,
679 size_t count)
680{
681 bool word_aligned;
682 unsigned head;
683 size_t len;
684
685 word_aligned = channel->info_word;
686 head = GET_TX_CHANNEL_INFO(channel, head);
687
688 len = min_t(size_t, count, channel->fifo_size - head);
689 if (len) {
690 smd_copy_to_fifo(channel->tx_fifo + head,
691 data,
692 len,
693 word_aligned);
694 }
695
696 if (len != count) {
697 smd_copy_to_fifo(channel->tx_fifo,
698 data + len,
699 count - len,
700 word_aligned);
701 }
702
703 head += count;
704 head &= (channel->fifo_size - 1);
705 SET_TX_CHANNEL_INFO(channel, head, head);
706
707 return count;
708}
709
710/**
711 * qcom_smd_send - write data to smd channel
712 * @channel: channel handle
713 * @data: buffer of data to write
714 * @len: number of bytes to write
715 *
716 * This is a blocking write of len bytes into the channel's tx ring buffer and
717 * signal the remote end. It will sleep until there is enough space available
718 * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid
719 * polling.
720 */
721static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
722 int len, bool wait)
723{
724 __le32 hdr[5] = { cpu_to_le32(len), };
725 int tlen = sizeof(hdr) + len;
726 int ret;
727
728 /* Word aligned channels only accept word size aligned data */
729 if (channel->info_word && len % 4)
730 return -EINVAL;
731
732 /* Reject packets that are too big */
733 if (tlen >= channel->fifo_size)
734 return -EINVAL;
735
736 ret = mutex_lock_interruptible(&channel->tx_lock);
737 if (ret)
738 return ret;
739
740 while (qcom_smd_get_tx_avail(channel) < tlen) {
741 if (!wait) {
742 ret = -ENOMEM;
743 goto out;
744 }
745
746 if (channel->state != SMD_CHANNEL_OPENED) {
747 ret = -EPIPE;
748 goto out;
749 }
750
751 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
752
753 ret = wait_event_interruptible(channel->fblockread_event,
754 qcom_smd_get_tx_avail(channel) >= tlen ||
755 channel->state != SMD_CHANNEL_OPENED);
756 if (ret)
757 goto out;
758
759 SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
760 }
761
762 SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
763
764 qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
765 qcom_smd_write_fifo(channel, data, len);
766
767 SET_TX_CHANNEL_FLAG(channel, fHEAD, 1);
768
769 /* Ensure ordering of channel info updates */
770 wmb();
771
772 qcom_smd_signal_channel(channel);
773
774out:
775 mutex_unlock(&channel->tx_lock);
776
777 return ret;
778}
779
780/*
781 * Helper for opening a channel
782 */
783static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
784 rpmsg_rx_cb_t cb)
785{
786 size_t bb_size;
787
788 /*
789 * Packets are maximum 4k, but reduce if the fifo is smaller
790 */
791 bb_size = min(channel->fifo_size, SZ_4K);
792 channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL);
793 if (!channel->bounce_buffer)
794 return -ENOMEM;
795
796 qcom_smd_channel_set_callback(channel, cb);
797 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
798 qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
799
800 return 0;
801}
802
803/*
804 * Helper for closing and resetting a channel
805 */
806static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
807{
808 qcom_smd_channel_set_callback(channel, NULL);
809
810 kfree(channel->bounce_buffer);
811 channel->bounce_buffer = NULL;
812
813 qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
814 qcom_smd_channel_reset(channel);
815}
816
817static struct qcom_smd_channel *
818qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
819{
820 struct qcom_smd_channel *channel;
821 struct qcom_smd_channel *ret = NULL;
822 unsigned long flags;
823 unsigned state;
824
825 spin_lock_irqsave(&edge->channels_lock, flags);
826 list_for_each_entry(channel, &edge->channels, list) {
827 if (strcmp(channel->name, name))
828 continue;
829
830 state = GET_RX_CHANNEL_INFO(channel, state);
831 if (state != SMD_CHANNEL_OPENING &&
832 state != SMD_CHANNEL_OPENED)
833 continue;
834
835 ret = channel;
836 break;
837 }
838 spin_unlock_irqrestore(&edge->channels_lock, flags);
839
840 return ret;
841}
842
843static void __ept_release(struct kref *kref)
844{
845 struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint,
846 refcount);
847 kfree(to_smd_endpoint(ept));
848}
849
850static struct rpmsg_endpoint *qcom_smd_create_ept(struct rpmsg_device *rpdev,
851 rpmsg_rx_cb_t cb, void *priv,
852 struct rpmsg_channel_info chinfo)
853{
854 struct qcom_smd_endpoint *qsept;
855 struct qcom_smd_channel *channel;
856 struct qcom_smd_device *qsdev = to_smd_device(rpdev);
857 struct qcom_smd_edge *edge = qsdev->edge;
858 struct rpmsg_endpoint *ept;
859 const char *name = chinfo.name;
860 int ret;
861
862 /* Wait up to HZ for the channel to appear */
863 ret = wait_event_interruptible_timeout(edge->new_channel_event,
864 (channel = qcom_smd_find_channel(edge, name)) != NULL,
865 HZ);
866 if (!ret)
867 return NULL;
868
869 if (channel->state != SMD_CHANNEL_CLOSED) {
870 dev_err(&rpdev->dev, "channel %s is busy\n", channel->name);
871 return NULL;
872 }
873
874 qsept = kzalloc(sizeof(*qsept), GFP_KERNEL);
875 if (!qsept)
876 return NULL;
877
878 ept = &qsept->ept;
879
880 kref_init(&ept->refcount);
881
882 ept->rpdev = rpdev;
883 ept->cb = cb;
884 ept->priv = priv;
885 ept->ops = &qcom_smd_endpoint_ops;
886
887 channel->qsept = qsept;
888 qsept->qsch = channel;
889
890 ret = qcom_smd_channel_open(channel, cb);
891 if (ret)
892 goto free_ept;
893
894 return ept;
895
896free_ept:
897 channel->qsept = NULL;
898 kref_put(&ept->refcount, __ept_release);
899 return NULL;
900}
901
902static void qcom_smd_destroy_ept(struct rpmsg_endpoint *ept)
903{
904 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
905 struct qcom_smd_channel *ch = qsept->qsch;
906
907 qcom_smd_channel_close(ch);
908 ch->qsept = NULL;
909 kref_put(&ept->refcount, __ept_release);
910}
911
912static int qcom_smd_send(struct rpmsg_endpoint *ept, void *data, int len)
913{
914 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
915
916 return __qcom_smd_send(qsept->qsch, data, len, true);
917}
918
919static int qcom_smd_trysend(struct rpmsg_endpoint *ept, void *data, int len)
920{
921 struct qcom_smd_endpoint *qsept = to_smd_endpoint(ept);
922
923 return __qcom_smd_send(qsept->qsch, data, len, false);
924}
925
926/*
927 * Finds the device_node for the smd child interested in this channel.
928 */
929static struct device_node *qcom_smd_match_channel(struct device_node *edge_node,
930 const char *channel)
931{
932 struct device_node *child;
933 const char *name;
934 const char *key;
935 int ret;
936
937 for_each_available_child_of_node(edge_node, child) {
938 key = "qcom,smd-channels";
939 ret = of_property_read_string(child, key, &name);
940 if (ret)
941 continue;
942
943 if (strcmp(name, channel) == 0)
944 return child;
945 }
946
947 return NULL;
948}
949
950static const struct rpmsg_device_ops qcom_smd_device_ops = {
951 .create_ept = qcom_smd_create_ept,
952};
953
954static const struct rpmsg_endpoint_ops qcom_smd_endpoint_ops = {
955 .destroy_ept = qcom_smd_destroy_ept,
956 .send = qcom_smd_send,
957 .trysend = qcom_smd_trysend,
958};
959
960/*
961 * Create a smd client device for channel that is being opened.
962 */
963static int qcom_smd_create_device(struct qcom_smd_channel *channel)
964{
965 struct qcom_smd_device *qsdev;
966 struct rpmsg_device *rpdev;
967 struct qcom_smd_edge *edge = channel->edge;
968
969 dev_dbg(&edge->dev, "registering '%s'\n", channel->name);
970
971 qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL);
972 if (!qsdev)
973 return -ENOMEM;
974
975 /* Link qsdev to our SMD edge */
976 qsdev->edge = edge;
977
978 /* Assign callbacks for rpmsg_device */
979 qsdev->rpdev.ops = &qcom_smd_device_ops;
980
981 /* Assign public information to the rpmsg_device */
982 rpdev = &qsdev->rpdev;
983 strncpy(rpdev->id.name, channel->name, RPMSG_NAME_SIZE);
984 rpdev->src = RPMSG_ADDR_ANY;
985 rpdev->dst = RPMSG_ADDR_ANY;
986
987 rpdev->dev.of_node = qcom_smd_match_channel(edge->of_node, channel->name);
988 rpdev->dev.parent = &edge->dev;
989
990 return rpmsg_register_device(rpdev);
991}
992
993/*
994 * Allocate the qcom_smd_channel object for a newly found smd channel,
995 * retrieving and validating the smem items involved.
996 */
997static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge,
998 unsigned smem_info_item,
999 unsigned smem_fifo_item,
1000 char *name)
1001{
1002 struct qcom_smd_channel *channel;
1003 size_t fifo_size;
1004 size_t info_size;
1005 void *fifo_base;
1006 void *info;
1007 int ret;
1008
1009 channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL);
1010 if (!channel)
1011 return ERR_PTR(-ENOMEM);
1012
1013 channel->edge = edge;
1014 channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL);
1015 if (!channel->name)
1016 return ERR_PTR(-ENOMEM);
1017
1018 mutex_init(&channel->tx_lock);
1019 spin_lock_init(&channel->recv_lock);
1020 init_waitqueue_head(&channel->fblockread_event);
1021
1022 info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
1023 if (IS_ERR(info)) {
1024 ret = PTR_ERR(info);
1025 goto free_name_and_channel;
1026 }
1027
1028 /*
1029 * Use the size of the item to figure out which channel info struct to
1030 * use.
1031 */
1032 if (info_size == 2 * sizeof(struct smd_channel_info_word)) {
1033 channel->info_word = info;
1034 } else if (info_size == 2 * sizeof(struct smd_channel_info)) {
1035 channel->info = info;
1036 } else {
1037 dev_err(&edge->dev,
1038 "channel info of size %zu not supported\n", info_size);
1039 ret = -EINVAL;
1040 goto free_name_and_channel;
1041 }
1042
1043 fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size);
1044 if (IS_ERR(fifo_base)) {
1045 ret = PTR_ERR(fifo_base);
1046 goto free_name_and_channel;
1047 }
1048
1049 /* The channel consist of a rx and tx fifo of equal size */
1050 fifo_size /= 2;
1051
1052 dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n",
1053 name, info_size, fifo_size);
1054
1055 channel->tx_fifo = fifo_base;
1056 channel->rx_fifo = fifo_base + fifo_size;
1057 channel->fifo_size = fifo_size;
1058
1059 qcom_smd_channel_reset(channel);
1060
1061 return channel;
1062
1063free_name_and_channel:
1064 devm_kfree(&edge->dev, channel->name);
1065 devm_kfree(&edge->dev, channel);
1066
1067 return ERR_PTR(ret);
1068}
1069
1070/*
1071 * Scans the allocation table for any newly allocated channels, calls
1072 * qcom_smd_create_channel() to create representations of these and add
1073 * them to the edge's list of channels.
1074 */
1075static void qcom_channel_scan_worker(struct work_struct *work)
1076{
1077 struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
1078 struct qcom_smd_alloc_entry *alloc_tbl;
1079 struct qcom_smd_alloc_entry *entry;
1080 struct qcom_smd_channel *channel;
1081 unsigned long flags;
1082 unsigned fifo_id;
1083 unsigned info_id;
1084 int tbl;
1085 int i;
1086 u32 eflags, cid;
1087
1088 for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) {
1089 alloc_tbl = qcom_smem_get(edge->remote_pid,
1090 smem_items[tbl].alloc_tbl_id, NULL);
1091 if (IS_ERR(alloc_tbl))
1092 continue;
1093
1094 for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) {
1095 entry = &alloc_tbl[i];
1096 eflags = le32_to_cpu(entry->flags);
1097 if (test_bit(i, edge->allocated[tbl]))
1098 continue;
1099
1100 if (entry->ref_count == 0)
1101 continue;
1102
1103 if (!entry->name[0])
1104 continue;
1105
1106 if (!(eflags & SMD_CHANNEL_FLAGS_PACKET))
1107 continue;
1108
1109 if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id)
1110 continue;
1111
1112 cid = le32_to_cpu(entry->cid);
1113 info_id = smem_items[tbl].info_base_id + cid;
1114 fifo_id = smem_items[tbl].fifo_base_id + cid;
1115
1116 channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name);
1117 if (IS_ERR(channel))
1118 continue;
1119
1120 spin_lock_irqsave(&edge->channels_lock, flags);
1121 list_add(&channel->list, &edge->channels);
1122 spin_unlock_irqrestore(&edge->channels_lock, flags);
1123
1124 dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
1125 set_bit(i, edge->allocated[tbl]);
1126
1127 wake_up_interruptible(&edge->new_channel_event);
1128 }
1129 }
1130
1131 schedule_work(&edge->state_work);
1132}
1133
1134/*
1135 * This per edge worker scans smem for any new channels and register these. It
1136 * then scans all registered channels for state changes that should be handled
1137 * by creating or destroying smd client devices for the registered channels.
1138 *
1139 * LOCKING: edge->channels_lock only needs to cover the list operations, as the
1140 * worker is killed before any channels are deallocated
1141 */
1142static void qcom_channel_state_worker(struct work_struct *work)
1143{
1144 struct qcom_smd_channel *channel;
1145 struct qcom_smd_edge *edge = container_of(work,
1146 struct qcom_smd_edge,
1147 state_work);
1148 struct rpmsg_channel_info chinfo;
1149 unsigned remote_state;
1150 unsigned long flags;
1151
1152 /*
1153 * Register a device for any closed channel where the remote processor
1154 * is showing interest in opening the channel.
1155 */
1156 spin_lock_irqsave(&edge->channels_lock, flags);
1157 list_for_each_entry(channel, &edge->channels, list) {
1158 if (channel->state != SMD_CHANNEL_CLOSED)
1159 continue;
1160
1161 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1162 if (remote_state != SMD_CHANNEL_OPENING &&
1163 remote_state != SMD_CHANNEL_OPENED)
1164 continue;
1165
1166 if (channel->registered)
1167 continue;
1168
1169 spin_unlock_irqrestore(&edge->channels_lock, flags);
1170 qcom_smd_create_device(channel);
1171 channel->registered = true;
1172 spin_lock_irqsave(&edge->channels_lock, flags);
1173
1174 channel->registered = true;
1175 }
1176
1177 /*
1178 * Unregister the device for any channel that is opened where the
1179 * remote processor is closing the channel.
1180 */
1181 list_for_each_entry(channel, &edge->channels, list) {
1182 if (channel->state != SMD_CHANNEL_OPENING &&
1183 channel->state != SMD_CHANNEL_OPENED)
1184 continue;
1185
1186 remote_state = GET_RX_CHANNEL_INFO(channel, state);
1187 if (remote_state == SMD_CHANNEL_OPENING ||
1188 remote_state == SMD_CHANNEL_OPENED)
1189 continue;
1190
1191 spin_unlock_irqrestore(&edge->channels_lock, flags);
1192
1193 strncpy(chinfo.name, channel->name, sizeof(chinfo.name));
1194 chinfo.src = RPMSG_ADDR_ANY;
1195 chinfo.dst = RPMSG_ADDR_ANY;
1196 rpmsg_unregister_device(&edge->dev, &chinfo);
1197 channel->registered = false;
1198 spin_lock_irqsave(&edge->channels_lock, flags);
1199 }
1200 spin_unlock_irqrestore(&edge->channels_lock, flags);
1201}
1202
1203/*
1204 * Parses an of_node describing an edge.
1205 */
1206static int qcom_smd_parse_edge(struct device *dev,
1207 struct device_node *node,
1208 struct qcom_smd_edge *edge)
1209{
1210 struct device_node *syscon_np;
1211 const char *key;
1212 int irq;
1213 int ret;
1214
1215 INIT_LIST_HEAD(&edge->channels);
1216 spin_lock_init(&edge->channels_lock);
1217
1218 INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
1219 INIT_WORK(&edge->state_work, qcom_channel_state_worker);
1220
1221 edge->of_node = of_node_get(node);
1222
1223 key = "qcom,smd-edge";
1224 ret = of_property_read_u32(node, key, &edge->edge_id);
1225 if (ret) {
1226 dev_err(dev, "edge missing %s property\n", key);
1227 return -EINVAL;
1228 }
1229
1230 edge->remote_pid = QCOM_SMEM_HOST_ANY;
1231 key = "qcom,remote-pid";
1232 of_property_read_u32(node, key, &edge->remote_pid);
1233
1234 syscon_np = of_parse_phandle(node, "qcom,ipc", 0);
1235 if (!syscon_np) {
1236 dev_err(dev, "no qcom,ipc node\n");
1237 return -ENODEV;
1238 }
1239
1240 edge->ipc_regmap = syscon_node_to_regmap(syscon_np);
1241 if (IS_ERR(edge->ipc_regmap))
1242 return PTR_ERR(edge->ipc_regmap);
1243
1244 key = "qcom,ipc";
1245 ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset);
1246 if (ret < 0) {
1247 dev_err(dev, "no offset in %s\n", key);
1248 return -EINVAL;
1249 }
1250
1251 ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit);
1252 if (ret < 0) {
1253 dev_err(dev, "no bit in %s\n", key);
1254 return -EINVAL;
1255 }
1256
1257 irq = irq_of_parse_and_map(node, 0);
1258 if (irq < 0) {
1259 dev_err(dev, "required smd interrupt missing\n");
1260 return -EINVAL;
1261 }
1262
1263 ret = devm_request_irq(dev, irq,
1264 qcom_smd_edge_intr, IRQF_TRIGGER_RISING,
1265 node->name, edge);
1266 if (ret) {
1267 dev_err(dev, "failed to request smd irq\n");
1268 return ret;
1269 }
1270
1271 edge->irq = irq;
1272
1273 return 0;
1274}
1275
1276/*
1277 * Release function for an edge.
1278 * Reset the state of each associated channel and free the edge context.
1279 */
1280static void qcom_smd_edge_release(struct device *dev)
1281{
1282 struct qcom_smd_channel *channel;
1283 struct qcom_smd_edge *edge = to_smd_edge(dev);
1284
1285 list_for_each_entry(channel, &edge->channels, list) {
1286 SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED);
1287 SET_RX_CHANNEL_INFO(channel, head, 0);
1288 SET_RX_CHANNEL_INFO(channel, tail, 0);
1289 }
1290
1291 kfree(edge);
1292}
1293
1294/**
1295 * qcom_smd_register_edge() - register an edge based on an device_node
1296 * @parent: parent device for the edge
1297 * @node: device_node describing the edge
1298 *
1299 * Returns an edge reference, or negative ERR_PTR() on failure.
1300 */
1301struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
1302 struct device_node *node)
1303{
1304 struct qcom_smd_edge *edge;
1305 int ret;
1306
1307 edge = kzalloc(sizeof(*edge), GFP_KERNEL);
1308 if (!edge)
1309 return ERR_PTR(-ENOMEM);
1310
1311 init_waitqueue_head(&edge->new_channel_event);
1312
1313 edge->dev.parent = parent;
1314 edge->dev.release = qcom_smd_edge_release;
1315 dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name);
1316 ret = device_register(&edge->dev);
1317 if (ret) {
1318 pr_err("failed to register smd edge\n");
1319 return ERR_PTR(ret);
1320 }
1321
1322 ret = qcom_smd_parse_edge(&edge->dev, node, edge);
1323 if (ret) {
1324 dev_err(&edge->dev, "failed to parse smd edge\n");
1325 goto unregister_dev;
1326 }
1327
1328 schedule_work(&edge->scan_work);
1329
1330 return edge;
1331
1332unregister_dev:
1333 put_device(&edge->dev);
1334 return ERR_PTR(ret);
1335}
1336EXPORT_SYMBOL(qcom_smd_register_edge);
1337
1338static int qcom_smd_remove_device(struct device *dev, void *data)
1339{
1340 device_unregister(dev);
1341
1342 return 0;
1343}
1344
1345/**
1346 * qcom_smd_unregister_edge() - release an edge and its children
1347 * @edge: edge reference acquired from qcom_smd_register_edge
1348 */
1349int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
1350{
1351 int ret;
1352
1353 disable_irq(edge->irq);
1354 cancel_work_sync(&edge->scan_work);
1355 cancel_work_sync(&edge->state_work);
1356
1357 ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device);
1358 if (ret)
1359 dev_warn(&edge->dev, "can't remove smd device: %d\n", ret);
1360
1361 device_unregister(&edge->dev);
1362
1363 return 0;
1364}
1365EXPORT_SYMBOL(qcom_smd_unregister_edge);
1366
1367static int qcom_smd_probe(struct platform_device *pdev)
1368{
1369 struct device_node *node;
1370 void *p;
1371
1372 /* Wait for smem */
1373 p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL);
1374 if (PTR_ERR(p) == -EPROBE_DEFER)
1375 return PTR_ERR(p);
1376
1377 for_each_available_child_of_node(pdev->dev.of_node, node)
1378 qcom_smd_register_edge(&pdev->dev, node);
1379
1380 return 0;
1381}
1382
1383static int qcom_smd_remove_edge(struct device *dev, void *data)
1384{
1385 struct qcom_smd_edge *edge = to_smd_edge(dev);
1386
1387 return qcom_smd_unregister_edge(edge);
1388}
1389
1390/*
1391 * Shut down all smd clients by making sure that each edge stops processing
1392 * events and scanning for new channels, then call destroy on the devices.
1393 */
1394static int qcom_smd_remove(struct platform_device *pdev)
1395{
1396 int ret;
1397
1398 ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge);
1399 if (ret)
1400 dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret);
1401
1402 return ret;
1403}
1404
1405static const struct of_device_id qcom_smd_of_match[] = {
1406 { .compatible = "qcom,smd" },
1407 {}
1408};
1409MODULE_DEVICE_TABLE(of, qcom_smd_of_match);
1410
1411static struct platform_driver qcom_smd_driver = {
1412 .probe = qcom_smd_probe,
1413 .remove = qcom_smd_remove,
1414 .driver = {
1415 .name = "qcom-smd",
1416 .of_match_table = qcom_smd_of_match,
1417 },
1418};
1419
1420static int __init qcom_smd_init(void)
1421{
1422 return platform_driver_register(&qcom_smd_driver);
1423}
1424subsys_initcall(qcom_smd_init);
1425
1426static void __exit qcom_smd_exit(void)
1427{
1428 platform_driver_unregister(&qcom_smd_driver);
1429}
1430module_exit(qcom_smd_exit);
1431
1432MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
1433MODULE_DESCRIPTION("Qualcomm Shared Memory Driver");
1434MODULE_LICENSE("GPL v2");