xref: /openbmc/linux/drivers/soc/apple/rtkit.c (revision 6562c9ac)
1 // SPDX-License-Identifier: GPL-2.0-only OR MIT
2 /*
3  * Apple RTKit IPC library
4  * Copyright (C) The Asahi Linux Contributors
5  */
6 
7 #include "rtkit-internal.h"
8 
9 enum {
10 	APPLE_RTKIT_PWR_STATE_OFF = 0x00, /* power off, cannot be restarted */
11 	APPLE_RTKIT_PWR_STATE_SLEEP = 0x01, /* sleeping, can be restarted */
12 	APPLE_RTKIT_PWR_STATE_QUIESCED = 0x10, /* running but no communication */
13 	APPLE_RTKIT_PWR_STATE_ON = 0x20, /* normal operating state */
14 };
15 
16 enum {
17 	APPLE_RTKIT_EP_MGMT = 0,
18 	APPLE_RTKIT_EP_CRASHLOG = 1,
19 	APPLE_RTKIT_EP_SYSLOG = 2,
20 	APPLE_RTKIT_EP_DEBUG = 3,
21 	APPLE_RTKIT_EP_IOREPORT = 4,
22 	APPLE_RTKIT_EP_OSLOG = 8,
23 };
24 
25 #define APPLE_RTKIT_MGMT_TYPE GENMASK_ULL(59, 52)
26 
27 enum {
28 	APPLE_RTKIT_MGMT_HELLO = 1,
29 	APPLE_RTKIT_MGMT_HELLO_REPLY = 2,
30 	APPLE_RTKIT_MGMT_STARTEP = 5,
31 	APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE = 6,
32 	APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK = 7,
33 	APPLE_RTKIT_MGMT_EPMAP = 8,
34 	APPLE_RTKIT_MGMT_EPMAP_REPLY = 8,
35 	APPLE_RTKIT_MGMT_SET_AP_PWR_STATE = 0xb,
36 	APPLE_RTKIT_MGMT_SET_AP_PWR_STATE_ACK = 0xb,
37 };
38 
39 #define APPLE_RTKIT_MGMT_HELLO_MINVER GENMASK_ULL(15, 0)
40 #define APPLE_RTKIT_MGMT_HELLO_MAXVER GENMASK_ULL(31, 16)
41 
42 #define APPLE_RTKIT_MGMT_EPMAP_LAST   BIT_ULL(51)
43 #define APPLE_RTKIT_MGMT_EPMAP_BASE   GENMASK_ULL(34, 32)
44 #define APPLE_RTKIT_MGMT_EPMAP_BITMAP GENMASK_ULL(31, 0)
45 
46 #define APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE BIT_ULL(0)
47 
48 #define APPLE_RTKIT_MGMT_STARTEP_EP   GENMASK_ULL(39, 32)
49 #define APPLE_RTKIT_MGMT_STARTEP_FLAG BIT_ULL(1)
50 
51 #define APPLE_RTKIT_MGMT_PWR_STATE GENMASK_ULL(15, 0)
52 
53 #define APPLE_RTKIT_CRASHLOG_CRASH 1
54 
55 #define APPLE_RTKIT_BUFFER_REQUEST	1
56 #define APPLE_RTKIT_BUFFER_REQUEST_SIZE GENMASK_ULL(51, 44)
57 #define APPLE_RTKIT_BUFFER_REQUEST_IOVA GENMASK_ULL(41, 0)
58 
59 #define APPLE_RTKIT_SYSLOG_TYPE GENMASK_ULL(59, 52)
60 
61 #define APPLE_RTKIT_SYSLOG_LOG 5
62 
63 #define APPLE_RTKIT_SYSLOG_INIT	     8
64 #define APPLE_RTKIT_SYSLOG_N_ENTRIES GENMASK_ULL(7, 0)
65 #define APPLE_RTKIT_SYSLOG_MSG_SIZE  GENMASK_ULL(31, 24)
66 
67 #define APPLE_RTKIT_OSLOG_TYPE GENMASK_ULL(63, 56)
68 #define APPLE_RTKIT_OSLOG_INIT	1
69 #define APPLE_RTKIT_OSLOG_ACK	3
70 
71 #define APPLE_RTKIT_MIN_SUPPORTED_VERSION 11
72 #define APPLE_RTKIT_MAX_SUPPORTED_VERSION 12
73 
74 struct apple_rtkit_msg {
75 	struct completion *completion;
76 	struct apple_mbox_msg mbox_msg;
77 };
78 
79 struct apple_rtkit_rx_work {
80 	struct apple_rtkit *rtk;
81 	u8 ep;
82 	u64 msg;
83 	struct work_struct work;
84 };
85 
86 bool apple_rtkit_is_running(struct apple_rtkit *rtk)
87 {
88 	if (rtk->crashed)
89 		return false;
90 	if ((rtk->iop_power_state & 0xff) != APPLE_RTKIT_PWR_STATE_ON)
91 		return false;
92 	if ((rtk->ap_power_state & 0xff) != APPLE_RTKIT_PWR_STATE_ON)
93 		return false;
94 	return true;
95 }
96 EXPORT_SYMBOL_GPL(apple_rtkit_is_running);
97 
98 bool apple_rtkit_is_crashed(struct apple_rtkit *rtk)
99 {
100 	return rtk->crashed;
101 }
102 EXPORT_SYMBOL_GPL(apple_rtkit_is_crashed);
103 
104 static void apple_rtkit_management_send(struct apple_rtkit *rtk, u8 type,
105 					u64 msg)
106 {
107 	msg &= ~APPLE_RTKIT_MGMT_TYPE;
108 	msg |= FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, type);
109 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_MGMT, msg, NULL, false);
110 }
111 
112 static void apple_rtkit_management_rx_hello(struct apple_rtkit *rtk, u64 msg)
113 {
114 	u64 reply;
115 
116 	int min_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MINVER, msg);
117 	int max_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MAXVER, msg);
118 	int want_ver = min(APPLE_RTKIT_MAX_SUPPORTED_VERSION, max_ver);
119 
120 	dev_dbg(rtk->dev, "RTKit: Min ver %d, max ver %d\n", min_ver, max_ver);
121 
122 	if (min_ver > APPLE_RTKIT_MAX_SUPPORTED_VERSION) {
123 		dev_err(rtk->dev, "RTKit: Firmware min version %d is too new\n",
124 			min_ver);
125 		goto abort_boot;
126 	}
127 
128 	if (max_ver < APPLE_RTKIT_MIN_SUPPORTED_VERSION) {
129 		dev_err(rtk->dev, "RTKit: Firmware max version %d is too old\n",
130 			max_ver);
131 		goto abort_boot;
132 	}
133 
134 	dev_info(rtk->dev, "RTKit: Initializing (protocol version %d)\n",
135 		 want_ver);
136 	rtk->version = want_ver;
137 
138 	reply = FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MINVER, want_ver);
139 	reply |= FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MAXVER, want_ver);
140 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_HELLO_REPLY, reply);
141 
142 	return;
143 
144 abort_boot:
145 	rtk->boot_result = -EINVAL;
146 	complete_all(&rtk->epmap_completion);
147 }
148 
149 static void apple_rtkit_management_rx_epmap(struct apple_rtkit *rtk, u64 msg)
150 {
151 	int i, ep;
152 	u64 reply;
153 	unsigned long bitmap = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BITMAP, msg);
154 	u32 base = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BASE, msg);
155 
156 	dev_dbg(rtk->dev,
157 		"RTKit: received endpoint bitmap 0x%lx with base 0x%x\n",
158 		bitmap, base);
159 
160 	for_each_set_bit(i, &bitmap, 32) {
161 		ep = 32 * base + i;
162 		dev_dbg(rtk->dev, "RTKit: Discovered endpoint 0x%02x\n", ep);
163 		set_bit(ep, rtk->endpoints);
164 	}
165 
166 	reply = FIELD_PREP(APPLE_RTKIT_MGMT_EPMAP_BASE, base);
167 	if (msg & APPLE_RTKIT_MGMT_EPMAP_LAST)
168 		reply |= APPLE_RTKIT_MGMT_EPMAP_LAST;
169 	else
170 		reply |= APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE;
171 
172 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_EPMAP_REPLY, reply);
173 
174 	if (!(msg & APPLE_RTKIT_MGMT_EPMAP_LAST))
175 		return;
176 
177 	for_each_set_bit(ep, rtk->endpoints, APPLE_RTKIT_APP_ENDPOINT_START) {
178 		switch (ep) {
179 		/* the management endpoint is started by default */
180 		case APPLE_RTKIT_EP_MGMT:
181 			break;
182 
183 		/* without starting these RTKit refuses to boot */
184 		case APPLE_RTKIT_EP_SYSLOG:
185 		case APPLE_RTKIT_EP_CRASHLOG:
186 		case APPLE_RTKIT_EP_DEBUG:
187 		case APPLE_RTKIT_EP_IOREPORT:
188 		case APPLE_RTKIT_EP_OSLOG:
189 			dev_dbg(rtk->dev,
190 				"RTKit: Starting system endpoint 0x%02x\n", ep);
191 			apple_rtkit_start_ep(rtk, ep);
192 			break;
193 
194 		default:
195 			dev_warn(rtk->dev,
196 				 "RTKit: Unknown system endpoint: 0x%02x\n",
197 				 ep);
198 		}
199 	}
200 
201 	rtk->boot_result = 0;
202 	complete_all(&rtk->epmap_completion);
203 }
204 
205 static void apple_rtkit_management_rx_iop_pwr_ack(struct apple_rtkit *rtk,
206 						  u64 msg)
207 {
208 	unsigned int new_state = FIELD_GET(APPLE_RTKIT_MGMT_PWR_STATE, msg);
209 
210 	dev_dbg(rtk->dev, "RTKit: IOP power state transition: 0x%x -> 0x%x\n",
211 		rtk->iop_power_state, new_state);
212 	rtk->iop_power_state = new_state;
213 
214 	complete_all(&rtk->iop_pwr_ack_completion);
215 }
216 
217 static void apple_rtkit_management_rx_ap_pwr_ack(struct apple_rtkit *rtk,
218 						 u64 msg)
219 {
220 	unsigned int new_state = FIELD_GET(APPLE_RTKIT_MGMT_PWR_STATE, msg);
221 
222 	dev_dbg(rtk->dev, "RTKit: AP power state transition: 0x%x -> 0x%x\n",
223 		rtk->ap_power_state, new_state);
224 	rtk->ap_power_state = new_state;
225 
226 	complete_all(&rtk->ap_pwr_ack_completion);
227 }
228 
229 static void apple_rtkit_management_rx(struct apple_rtkit *rtk, u64 msg)
230 {
231 	u8 type = FIELD_GET(APPLE_RTKIT_MGMT_TYPE, msg);
232 
233 	switch (type) {
234 	case APPLE_RTKIT_MGMT_HELLO:
235 		apple_rtkit_management_rx_hello(rtk, msg);
236 		break;
237 	case APPLE_RTKIT_MGMT_EPMAP:
238 		apple_rtkit_management_rx_epmap(rtk, msg);
239 		break;
240 	case APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK:
241 		apple_rtkit_management_rx_iop_pwr_ack(rtk, msg);
242 		break;
243 	case APPLE_RTKIT_MGMT_SET_AP_PWR_STATE_ACK:
244 		apple_rtkit_management_rx_ap_pwr_ack(rtk, msg);
245 		break;
246 	default:
247 		dev_warn(
248 			rtk->dev,
249 			"RTKit: unknown management message: 0x%llx (type: 0x%02x)\n",
250 			msg, type);
251 	}
252 }
253 
254 static int apple_rtkit_common_rx_get_buffer(struct apple_rtkit *rtk,
255 					    struct apple_rtkit_shmem *buffer,
256 					    u8 ep, u64 msg)
257 {
258 	size_t n_4kpages = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_SIZE, msg);
259 	u64 reply;
260 	int err;
261 
262 	buffer->buffer = NULL;
263 	buffer->iomem = NULL;
264 	buffer->is_mapped = false;
265 	buffer->iova = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_IOVA, msg);
266 	buffer->size = n_4kpages << 12;
267 
268 	dev_dbg(rtk->dev, "RTKit: buffer request for 0x%zx bytes at %pad\n",
269 		buffer->size, &buffer->iova);
270 
271 	if (buffer->iova &&
272 	    (!rtk->ops->shmem_setup || !rtk->ops->shmem_destroy)) {
273 		err = -EINVAL;
274 		goto error;
275 	}
276 
277 	if (rtk->ops->shmem_setup) {
278 		err = rtk->ops->shmem_setup(rtk->cookie, buffer);
279 		if (err)
280 			goto error;
281 	} else {
282 		buffer->buffer = dma_alloc_coherent(rtk->dev, buffer->size,
283 						    &buffer->iova, GFP_KERNEL);
284 		if (!buffer->buffer) {
285 			err = -ENOMEM;
286 			goto error;
287 		}
288 	}
289 
290 	if (!buffer->is_mapped) {
291 		reply = FIELD_PREP(APPLE_RTKIT_SYSLOG_TYPE,
292 				   APPLE_RTKIT_BUFFER_REQUEST);
293 		reply |= FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_SIZE, n_4kpages);
294 		reply |= FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_IOVA,
295 				    buffer->iova);
296 		apple_rtkit_send_message(rtk, ep, reply, NULL, false);
297 	}
298 
299 	return 0;
300 
301 error:
302 	buffer->buffer = NULL;
303 	buffer->iomem = NULL;
304 	buffer->iova = 0;
305 	buffer->size = 0;
306 	buffer->is_mapped = false;
307 	return err;
308 }
309 
310 static void apple_rtkit_free_buffer(struct apple_rtkit *rtk,
311 				    struct apple_rtkit_shmem *bfr)
312 {
313 	if (bfr->size == 0)
314 		return;
315 
316 	if (rtk->ops->shmem_destroy)
317 		rtk->ops->shmem_destroy(rtk->cookie, bfr);
318 	else if (bfr->buffer)
319 		dma_free_coherent(rtk->dev, bfr->size, bfr->buffer, bfr->iova);
320 
321 	bfr->buffer = NULL;
322 	bfr->iomem = NULL;
323 	bfr->iova = 0;
324 	bfr->size = 0;
325 	bfr->is_mapped = false;
326 }
327 
328 static void apple_rtkit_memcpy(struct apple_rtkit *rtk, void *dst,
329 			       struct apple_rtkit_shmem *bfr, size_t offset,
330 			       size_t len)
331 {
332 	if (bfr->iomem)
333 		memcpy_fromio(dst, bfr->iomem + offset, len);
334 	else
335 		memcpy(dst, bfr->buffer + offset, len);
336 }
337 
338 static void apple_rtkit_crashlog_rx(struct apple_rtkit *rtk, u64 msg)
339 {
340 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
341 	u8 *bfr;
342 
343 	if (type != APPLE_RTKIT_CRASHLOG_CRASH) {
344 		dev_warn(rtk->dev, "RTKit: Unknown crashlog message: %llx\n",
345 			 msg);
346 		return;
347 	}
348 
349 	if (!rtk->crashlog_buffer.size) {
350 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->crashlog_buffer,
351 						 APPLE_RTKIT_EP_CRASHLOG, msg);
352 		return;
353 	}
354 
355 	dev_err(rtk->dev, "RTKit: co-processor has crashed\n");
356 
357 	/*
358 	 * create a shadow copy here to make sure the co-processor isn't able
359 	 * to change the log while we're dumping it. this also ensures
360 	 * the buffer is in normal memory and not iomem for e.g. the SMC
361 	 */
362 	bfr = kzalloc(rtk->crashlog_buffer.size, GFP_KERNEL);
363 	if (bfr) {
364 		apple_rtkit_memcpy(rtk, bfr, &rtk->crashlog_buffer, 0,
365 				   rtk->crashlog_buffer.size);
366 		apple_rtkit_crashlog_dump(rtk, bfr, rtk->crashlog_buffer.size);
367 		kfree(bfr);
368 	} else {
369 		dev_err(rtk->dev,
370 			"RTKit: Couldn't allocate crashlog shadow buffer\n");
371 	}
372 
373 	rtk->crashed = true;
374 	if (rtk->ops->crashed)
375 		rtk->ops->crashed(rtk->cookie);
376 }
377 
378 static void apple_rtkit_ioreport_rx(struct apple_rtkit *rtk, u64 msg)
379 {
380 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
381 
382 	switch (type) {
383 	case APPLE_RTKIT_BUFFER_REQUEST:
384 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->ioreport_buffer,
385 						 APPLE_RTKIT_EP_IOREPORT, msg);
386 		break;
387 	/* unknown, must be ACKed or the co-processor will hang */
388 	case 0x8:
389 	case 0xc:
390 		apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_IOREPORT, msg,
391 					 NULL, false);
392 		break;
393 	default:
394 		dev_warn(rtk->dev, "RTKit: Unknown ioreport message: %llx\n",
395 			 msg);
396 	}
397 }
398 
399 static void apple_rtkit_syslog_rx_init(struct apple_rtkit *rtk, u64 msg)
400 {
401 	rtk->syslog_n_entries = FIELD_GET(APPLE_RTKIT_SYSLOG_N_ENTRIES, msg);
402 	rtk->syslog_msg_size = FIELD_GET(APPLE_RTKIT_SYSLOG_MSG_SIZE, msg);
403 
404 	rtk->syslog_msg_buffer = kzalloc(rtk->syslog_msg_size, GFP_KERNEL);
405 
406 	dev_dbg(rtk->dev,
407 		"RTKit: syslog initialized: entries: %zd, msg_size: %zd\n",
408 		rtk->syslog_n_entries, rtk->syslog_msg_size);
409 }
410 
411 static void apple_rtkit_syslog_rx_log(struct apple_rtkit *rtk, u64 msg)
412 {
413 	u8 idx = msg & 0xff;
414 	char log_context[24];
415 	size_t entry_size = 0x20 + rtk->syslog_msg_size;
416 
417 	if (!rtk->syslog_msg_buffer) {
418 		dev_warn(
419 			rtk->dev,
420 			"RTKit: received syslog message but no syslog_msg_buffer\n");
421 		goto done;
422 	}
423 	if (!rtk->syslog_buffer.size) {
424 		dev_warn(
425 			rtk->dev,
426 			"RTKit: received syslog message but syslog_buffer.size is zero\n");
427 		goto done;
428 	}
429 	if (!rtk->syslog_buffer.buffer && !rtk->syslog_buffer.iomem) {
430 		dev_warn(
431 			rtk->dev,
432 			"RTKit: received syslog message but no syslog_buffer.buffer or syslog_buffer.iomem\n");
433 		goto done;
434 	}
435 	if (idx > rtk->syslog_n_entries) {
436 		dev_warn(rtk->dev, "RTKit: syslog index %d out of range\n",
437 			 idx);
438 		goto done;
439 	}
440 
441 	apple_rtkit_memcpy(rtk, log_context, &rtk->syslog_buffer,
442 			   idx * entry_size + 8, sizeof(log_context));
443 	apple_rtkit_memcpy(rtk, rtk->syslog_msg_buffer, &rtk->syslog_buffer,
444 			   idx * entry_size + 8 + sizeof(log_context),
445 			   rtk->syslog_msg_size);
446 
447 	log_context[sizeof(log_context) - 1] = 0;
448 	rtk->syslog_msg_buffer[rtk->syslog_msg_size - 1] = 0;
449 	dev_info(rtk->dev, "RTKit: syslog message: %s: %s\n", log_context,
450 		 rtk->syslog_msg_buffer);
451 
452 done:
453 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_SYSLOG, msg, NULL, false);
454 }
455 
456 static void apple_rtkit_syslog_rx(struct apple_rtkit *rtk, u64 msg)
457 {
458 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
459 
460 	switch (type) {
461 	case APPLE_RTKIT_BUFFER_REQUEST:
462 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->syslog_buffer,
463 						 APPLE_RTKIT_EP_SYSLOG, msg);
464 		break;
465 	case APPLE_RTKIT_SYSLOG_INIT:
466 		apple_rtkit_syslog_rx_init(rtk, msg);
467 		break;
468 	case APPLE_RTKIT_SYSLOG_LOG:
469 		apple_rtkit_syslog_rx_log(rtk, msg);
470 		break;
471 	default:
472 		dev_warn(rtk->dev, "RTKit: Unknown syslog message: %llx\n",
473 			 msg);
474 	}
475 }
476 
477 static void apple_rtkit_oslog_rx_init(struct apple_rtkit *rtk, u64 msg)
478 {
479 	u64 ack;
480 
481 	dev_dbg(rtk->dev, "RTKit: oslog init: msg: 0x%llx\n", msg);
482 	ack = FIELD_PREP(APPLE_RTKIT_OSLOG_TYPE, APPLE_RTKIT_OSLOG_ACK);
483 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_OSLOG, ack, NULL, false);
484 }
485 
486 static void apple_rtkit_oslog_rx(struct apple_rtkit *rtk, u64 msg)
487 {
488 	u8 type = FIELD_GET(APPLE_RTKIT_OSLOG_TYPE, msg);
489 
490 	switch (type) {
491 	case APPLE_RTKIT_OSLOG_INIT:
492 		apple_rtkit_oslog_rx_init(rtk, msg);
493 		break;
494 	default:
495 		dev_warn(rtk->dev, "RTKit: Unknown oslog message: %llx\n", msg);
496 	}
497 }
498 
499 static void apple_rtkit_rx_work(struct work_struct *work)
500 {
501 	struct apple_rtkit_rx_work *rtk_work =
502 		container_of(work, struct apple_rtkit_rx_work, work);
503 	struct apple_rtkit *rtk = rtk_work->rtk;
504 
505 	switch (rtk_work->ep) {
506 	case APPLE_RTKIT_EP_MGMT:
507 		apple_rtkit_management_rx(rtk, rtk_work->msg);
508 		break;
509 	case APPLE_RTKIT_EP_CRASHLOG:
510 		apple_rtkit_crashlog_rx(rtk, rtk_work->msg);
511 		break;
512 	case APPLE_RTKIT_EP_SYSLOG:
513 		apple_rtkit_syslog_rx(rtk, rtk_work->msg);
514 		break;
515 	case APPLE_RTKIT_EP_IOREPORT:
516 		apple_rtkit_ioreport_rx(rtk, rtk_work->msg);
517 		break;
518 	case APPLE_RTKIT_EP_OSLOG:
519 		apple_rtkit_oslog_rx(rtk, rtk_work->msg);
520 		break;
521 	case APPLE_RTKIT_APP_ENDPOINT_START ... 0xff:
522 		if (rtk->ops->recv_message)
523 			rtk->ops->recv_message(rtk->cookie, rtk_work->ep,
524 					       rtk_work->msg);
525 		else
526 			dev_warn(
527 				rtk->dev,
528 				"Received unexpected message to EP%02d: %llx\n",
529 				rtk_work->ep, rtk_work->msg);
530 		break;
531 	default:
532 		dev_warn(rtk->dev,
533 			 "RTKit: message to unknown endpoint %02x: %llx\n",
534 			 rtk_work->ep, rtk_work->msg);
535 	}
536 
537 	kfree(rtk_work);
538 }
539 
540 static void apple_rtkit_rx(struct mbox_client *cl, void *mssg)
541 {
542 	struct apple_rtkit *rtk = container_of(cl, struct apple_rtkit, mbox_cl);
543 	struct apple_mbox_msg *msg = mssg;
544 	struct apple_rtkit_rx_work *work;
545 	u8 ep = msg->msg1;
546 
547 	/*
548 	 * The message was read from a MMIO FIFO and we have to make
549 	 * sure all reads from buffers sent with that message happen
550 	 * afterwards.
551 	 */
552 	dma_rmb();
553 
554 	if (!test_bit(ep, rtk->endpoints))
555 		dev_warn(rtk->dev,
556 			 "RTKit: Message to undiscovered endpoint 0x%02x\n",
557 			 ep);
558 
559 	if (ep >= APPLE_RTKIT_APP_ENDPOINT_START &&
560 	    rtk->ops->recv_message_early &&
561 	    rtk->ops->recv_message_early(rtk->cookie, ep, msg->msg0))
562 		return;
563 
564 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
565 	if (!work)
566 		return;
567 
568 	work->rtk = rtk;
569 	work->ep = ep;
570 	work->msg = msg->msg0;
571 	INIT_WORK(&work->work, apple_rtkit_rx_work);
572 	queue_work(rtk->wq, &work->work);
573 }
574 
575 static void apple_rtkit_tx_done(struct mbox_client *cl, void *mssg, int r)
576 {
577 	struct apple_rtkit_msg *msg =
578 		container_of(mssg, struct apple_rtkit_msg, mbox_msg);
579 
580 	if (r == -ETIME)
581 		return;
582 
583 	if (msg->completion)
584 		complete(msg->completion);
585 	kfree(msg);
586 }
587 
588 int apple_rtkit_send_message(struct apple_rtkit *rtk, u8 ep, u64 message,
589 			     struct completion *completion, bool atomic)
590 {
591 	struct apple_rtkit_msg *msg;
592 	int ret;
593 	gfp_t flags;
594 
595 	if (rtk->crashed)
596 		return -EINVAL;
597 	if (ep >= APPLE_RTKIT_APP_ENDPOINT_START &&
598 	    !apple_rtkit_is_running(rtk))
599 		return -EINVAL;
600 
601 	if (atomic)
602 		flags = GFP_ATOMIC;
603 	else
604 		flags = GFP_KERNEL;
605 
606 	msg = kzalloc(sizeof(*msg), flags);
607 	if (!msg)
608 		return -ENOMEM;
609 
610 	msg->mbox_msg.msg0 = message;
611 	msg->mbox_msg.msg1 = ep;
612 	msg->completion = completion;
613 
614 	/*
615 	 * The message will be sent with a MMIO write. We need the barrier
616 	 * here to ensure any previous writes to buffers are visible to the
617 	 * device before that MMIO write happens.
618 	 */
619 	dma_wmb();
620 
621 	ret = mbox_send_message(rtk->mbox_chan, &msg->mbox_msg);
622 	if (ret < 0) {
623 		kfree(msg);
624 		return ret;
625 	}
626 
627 	return 0;
628 }
629 EXPORT_SYMBOL_GPL(apple_rtkit_send_message);
630 
631 int apple_rtkit_send_message_wait(struct apple_rtkit *rtk, u8 ep, u64 message,
632 				  unsigned long timeout, bool atomic)
633 {
634 	DECLARE_COMPLETION_ONSTACK(completion);
635 	int ret;
636 	long t;
637 
638 	ret = apple_rtkit_send_message(rtk, ep, message, &completion, atomic);
639 	if (ret < 0)
640 		return ret;
641 
642 	if (atomic) {
643 		ret = mbox_flush(rtk->mbox_chan, timeout);
644 		if (ret < 0)
645 			return ret;
646 
647 		if (try_wait_for_completion(&completion))
648 			return 0;
649 
650 		return -ETIME;
651 	} else {
652 		t = wait_for_completion_interruptible_timeout(
653 			&completion, msecs_to_jiffies(timeout));
654 		if (t < 0)
655 			return t;
656 		else if (t == 0)
657 			return -ETIME;
658 		return 0;
659 	}
660 }
661 EXPORT_SYMBOL_GPL(apple_rtkit_send_message_wait);
662 
663 int apple_rtkit_start_ep(struct apple_rtkit *rtk, u8 endpoint)
664 {
665 	u64 msg;
666 
667 	if (!test_bit(endpoint, rtk->endpoints))
668 		return -EINVAL;
669 	if (endpoint >= APPLE_RTKIT_APP_ENDPOINT_START &&
670 	    !apple_rtkit_is_running(rtk))
671 		return -EINVAL;
672 
673 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_STARTEP_EP, endpoint);
674 	msg |= APPLE_RTKIT_MGMT_STARTEP_FLAG;
675 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_STARTEP, msg);
676 
677 	return 0;
678 }
679 EXPORT_SYMBOL_GPL(apple_rtkit_start_ep);
680 
681 static int apple_rtkit_request_mbox_chan(struct apple_rtkit *rtk)
682 {
683 	if (rtk->mbox_name)
684 		rtk->mbox_chan = mbox_request_channel_byname(&rtk->mbox_cl,
685 							     rtk->mbox_name);
686 	else
687 		rtk->mbox_chan =
688 			mbox_request_channel(&rtk->mbox_cl, rtk->mbox_idx);
689 
690 	if (IS_ERR(rtk->mbox_chan))
691 		return PTR_ERR(rtk->mbox_chan);
692 	return 0;
693 }
694 
695 static struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
696 					    const char *mbox_name, int mbox_idx,
697 					    const struct apple_rtkit_ops *ops)
698 {
699 	struct apple_rtkit *rtk;
700 	int ret;
701 
702 	if (!ops)
703 		return ERR_PTR(-EINVAL);
704 
705 	rtk = kzalloc(sizeof(*rtk), GFP_KERNEL);
706 	if (!rtk)
707 		return ERR_PTR(-ENOMEM);
708 
709 	rtk->dev = dev;
710 	rtk->cookie = cookie;
711 	rtk->ops = ops;
712 
713 	init_completion(&rtk->epmap_completion);
714 	init_completion(&rtk->iop_pwr_ack_completion);
715 	init_completion(&rtk->ap_pwr_ack_completion);
716 
717 	bitmap_zero(rtk->endpoints, APPLE_RTKIT_MAX_ENDPOINTS);
718 	set_bit(APPLE_RTKIT_EP_MGMT, rtk->endpoints);
719 
720 	rtk->mbox_name = mbox_name;
721 	rtk->mbox_idx = mbox_idx;
722 	rtk->mbox_cl.dev = dev;
723 	rtk->mbox_cl.tx_block = false;
724 	rtk->mbox_cl.knows_txdone = false;
725 	rtk->mbox_cl.rx_callback = &apple_rtkit_rx;
726 	rtk->mbox_cl.tx_done = &apple_rtkit_tx_done;
727 
728 	rtk->wq = alloc_ordered_workqueue("rtkit-%s", WQ_MEM_RECLAIM,
729 					  dev_name(rtk->dev));
730 	if (!rtk->wq) {
731 		ret = -ENOMEM;
732 		goto free_rtk;
733 	}
734 
735 	ret = apple_rtkit_request_mbox_chan(rtk);
736 	if (ret)
737 		goto destroy_wq;
738 
739 	return rtk;
740 
741 destroy_wq:
742 	destroy_workqueue(rtk->wq);
743 free_rtk:
744 	kfree(rtk);
745 	return ERR_PTR(ret);
746 }
747 
748 static int apple_rtkit_wait_for_completion(struct completion *c)
749 {
750 	long t;
751 
752 	t = wait_for_completion_interruptible_timeout(c,
753 						      msecs_to_jiffies(1000));
754 	if (t < 0)
755 		return t;
756 	else if (t == 0)
757 		return -ETIME;
758 	else
759 		return 0;
760 }
761 
762 int apple_rtkit_reinit(struct apple_rtkit *rtk)
763 {
764 	/* make sure we don't handle any messages while reinitializing */
765 	mbox_free_channel(rtk->mbox_chan);
766 	flush_workqueue(rtk->wq);
767 
768 	apple_rtkit_free_buffer(rtk, &rtk->ioreport_buffer);
769 	apple_rtkit_free_buffer(rtk, &rtk->crashlog_buffer);
770 	apple_rtkit_free_buffer(rtk, &rtk->syslog_buffer);
771 
772 	kfree(rtk->syslog_msg_buffer);
773 
774 	rtk->syslog_msg_buffer = NULL;
775 	rtk->syslog_n_entries = 0;
776 	rtk->syslog_msg_size = 0;
777 
778 	bitmap_zero(rtk->endpoints, APPLE_RTKIT_MAX_ENDPOINTS);
779 	set_bit(APPLE_RTKIT_EP_MGMT, rtk->endpoints);
780 
781 	reinit_completion(&rtk->epmap_completion);
782 	reinit_completion(&rtk->iop_pwr_ack_completion);
783 	reinit_completion(&rtk->ap_pwr_ack_completion);
784 
785 	rtk->crashed = false;
786 	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_OFF;
787 	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_OFF;
788 
789 	return apple_rtkit_request_mbox_chan(rtk);
790 }
791 EXPORT_SYMBOL_GPL(apple_rtkit_reinit);
792 
793 static int apple_rtkit_set_ap_power_state(struct apple_rtkit *rtk,
794 					  unsigned int state)
795 {
796 	u64 msg;
797 	int ret;
798 
799 	reinit_completion(&rtk->ap_pwr_ack_completion);
800 
801 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, state);
802 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_AP_PWR_STATE,
803 				    msg);
804 
805 	ret = apple_rtkit_wait_for_completion(&rtk->ap_pwr_ack_completion);
806 	if (ret)
807 		return ret;
808 
809 	if (rtk->ap_power_state != state)
810 		return -EINVAL;
811 	return 0;
812 }
813 
814 static int apple_rtkit_set_iop_power_state(struct apple_rtkit *rtk,
815 					   unsigned int state)
816 {
817 	u64 msg;
818 	int ret;
819 
820 	reinit_completion(&rtk->iop_pwr_ack_completion);
821 
822 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, state);
823 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE,
824 				    msg);
825 
826 	ret = apple_rtkit_wait_for_completion(&rtk->iop_pwr_ack_completion);
827 	if (ret)
828 		return ret;
829 
830 	if (rtk->iop_power_state != state)
831 		return -EINVAL;
832 	return 0;
833 }
834 
835 int apple_rtkit_boot(struct apple_rtkit *rtk)
836 {
837 	int ret;
838 
839 	if (apple_rtkit_is_running(rtk))
840 		return 0;
841 	if (rtk->crashed)
842 		return -EINVAL;
843 
844 	dev_dbg(rtk->dev, "RTKit: waiting for boot to finish\n");
845 	ret = apple_rtkit_wait_for_completion(&rtk->epmap_completion);
846 	if (ret)
847 		return ret;
848 	if (rtk->boot_result)
849 		return rtk->boot_result;
850 
851 	dev_dbg(rtk->dev, "RTKit: waiting for IOP power state ACK\n");
852 	ret = apple_rtkit_wait_for_completion(&rtk->iop_pwr_ack_completion);
853 	if (ret)
854 		return ret;
855 
856 	return apple_rtkit_set_ap_power_state(rtk, APPLE_RTKIT_PWR_STATE_ON);
857 }
858 EXPORT_SYMBOL_GPL(apple_rtkit_boot);
859 
860 int apple_rtkit_shutdown(struct apple_rtkit *rtk)
861 {
862 	int ret;
863 
864 	/* if OFF is used here the co-processor will not wake up again */
865 	ret = apple_rtkit_set_ap_power_state(rtk,
866 					     APPLE_RTKIT_PWR_STATE_QUIESCED);
867 	if (ret)
868 		return ret;
869 
870 	ret = apple_rtkit_set_iop_power_state(rtk, APPLE_RTKIT_PWR_STATE_SLEEP);
871 	if (ret)
872 		return ret;
873 
874 	return apple_rtkit_reinit(rtk);
875 }
876 EXPORT_SYMBOL_GPL(apple_rtkit_shutdown);
877 
878 int apple_rtkit_quiesce(struct apple_rtkit *rtk)
879 {
880 	int ret;
881 
882 	ret = apple_rtkit_set_ap_power_state(rtk,
883 					     APPLE_RTKIT_PWR_STATE_QUIESCED);
884 	if (ret)
885 		return ret;
886 
887 	ret = apple_rtkit_set_iop_power_state(rtk,
888 					      APPLE_RTKIT_PWR_STATE_QUIESCED);
889 	if (ret)
890 		return ret;
891 
892 	ret = apple_rtkit_reinit(rtk);
893 	if (ret)
894 		return ret;
895 
896 	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_QUIESCED;
897 	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_QUIESCED;
898 	return 0;
899 }
900 EXPORT_SYMBOL_GPL(apple_rtkit_quiesce);
901 
902 int apple_rtkit_wake(struct apple_rtkit *rtk)
903 {
904 	u64 msg;
905 
906 	if (apple_rtkit_is_running(rtk))
907 		return -EINVAL;
908 
909 	reinit_completion(&rtk->iop_pwr_ack_completion);
910 
911 	/*
912 	 * Use open-coded apple_rtkit_set_iop_power_state since apple_rtkit_boot
913 	 * will wait for the completion anyway.
914 	 */
915 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, APPLE_RTKIT_PWR_STATE_ON);
916 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE,
917 				    msg);
918 
919 	return apple_rtkit_boot(rtk);
920 }
921 EXPORT_SYMBOL_GPL(apple_rtkit_wake);
922 
923 static void apple_rtkit_free(struct apple_rtkit *rtk)
924 {
925 	mbox_free_channel(rtk->mbox_chan);
926 	destroy_workqueue(rtk->wq);
927 
928 	apple_rtkit_free_buffer(rtk, &rtk->ioreport_buffer);
929 	apple_rtkit_free_buffer(rtk, &rtk->crashlog_buffer);
930 	apple_rtkit_free_buffer(rtk, &rtk->syslog_buffer);
931 
932 	kfree(rtk->syslog_msg_buffer);
933 	kfree(rtk);
934 }
935 
936 struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
937 					  const char *mbox_name, int mbox_idx,
938 					  const struct apple_rtkit_ops *ops)
939 {
940 	struct apple_rtkit *rtk;
941 	int ret;
942 
943 	rtk = apple_rtkit_init(dev, cookie, mbox_name, mbox_idx, ops);
944 	if (IS_ERR(rtk))
945 		return rtk;
946 
947 	ret = devm_add_action_or_reset(dev, (void (*)(void *))apple_rtkit_free,
948 				       rtk);
949 	if (ret)
950 		return ERR_PTR(ret);
951 
952 	return rtk;
953 }
954 EXPORT_SYMBOL_GPL(devm_apple_rtkit_init);
955 
956 MODULE_LICENSE("Dual MIT/GPL");
957 MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
958 MODULE_DESCRIPTION("Apple RTKit driver");
959