xref: /openbmc/linux/drivers/soc/apple/rtkit.c (revision cf1788fb)
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_IDLE = 0x201, /* sleeping, retain state */
13 	APPLE_RTKIT_PWR_STATE_QUIESCED = 0x10, /* running but no communication */
14 	APPLE_RTKIT_PWR_STATE_ON = 0x20, /* normal operating state */
15 };
16 
17 enum {
18 	APPLE_RTKIT_EP_MGMT = 0,
19 	APPLE_RTKIT_EP_CRASHLOG = 1,
20 	APPLE_RTKIT_EP_SYSLOG = 2,
21 	APPLE_RTKIT_EP_DEBUG = 3,
22 	APPLE_RTKIT_EP_IOREPORT = 4,
23 	APPLE_RTKIT_EP_OSLOG = 8,
24 };
25 
26 #define APPLE_RTKIT_MGMT_TYPE GENMASK_ULL(59, 52)
27 
28 enum {
29 	APPLE_RTKIT_MGMT_HELLO = 1,
30 	APPLE_RTKIT_MGMT_HELLO_REPLY = 2,
31 	APPLE_RTKIT_MGMT_STARTEP = 5,
32 	APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE = 6,
33 	APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK = 7,
34 	APPLE_RTKIT_MGMT_EPMAP = 8,
35 	APPLE_RTKIT_MGMT_EPMAP_REPLY = 8,
36 	APPLE_RTKIT_MGMT_SET_AP_PWR_STATE = 0xb,
37 	APPLE_RTKIT_MGMT_SET_AP_PWR_STATE_ACK = 0xb,
38 };
39 
40 #define APPLE_RTKIT_MGMT_HELLO_MINVER GENMASK_ULL(15, 0)
41 #define APPLE_RTKIT_MGMT_HELLO_MAXVER GENMASK_ULL(31, 16)
42 
43 #define APPLE_RTKIT_MGMT_EPMAP_LAST   BIT_ULL(51)
44 #define APPLE_RTKIT_MGMT_EPMAP_BASE   GENMASK_ULL(34, 32)
45 #define APPLE_RTKIT_MGMT_EPMAP_BITMAP GENMASK_ULL(31, 0)
46 
47 #define APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE BIT_ULL(0)
48 
49 #define APPLE_RTKIT_MGMT_STARTEP_EP   GENMASK_ULL(39, 32)
50 #define APPLE_RTKIT_MGMT_STARTEP_FLAG BIT_ULL(1)
51 
52 #define APPLE_RTKIT_MGMT_PWR_STATE GENMASK_ULL(15, 0)
53 
54 #define APPLE_RTKIT_CRASHLOG_CRASH 1
55 
56 #define APPLE_RTKIT_BUFFER_REQUEST	1
57 #define APPLE_RTKIT_BUFFER_REQUEST_SIZE GENMASK_ULL(51, 44)
58 #define APPLE_RTKIT_BUFFER_REQUEST_IOVA GENMASK_ULL(43, 0)
59 
60 #define APPLE_RTKIT_SYSLOG_TYPE GENMASK_ULL(59, 52)
61 
62 #define APPLE_RTKIT_SYSLOG_LOG 5
63 
64 #define APPLE_RTKIT_SYSLOG_INIT	     8
65 #define APPLE_RTKIT_SYSLOG_N_ENTRIES GENMASK_ULL(7, 0)
66 #define APPLE_RTKIT_SYSLOG_MSG_SIZE  GENMASK_ULL(31, 24)
67 
68 #define APPLE_RTKIT_OSLOG_TYPE GENMASK_ULL(63, 56)
69 #define APPLE_RTKIT_OSLOG_INIT	1
70 #define APPLE_RTKIT_OSLOG_ACK	3
71 
72 #define APPLE_RTKIT_MIN_SUPPORTED_VERSION 11
73 #define APPLE_RTKIT_MAX_SUPPORTED_VERSION 12
74 
75 struct apple_rtkit_msg {
76 	struct completion *completion;
77 	struct apple_mbox_msg mbox_msg;
78 };
79 
80 struct apple_rtkit_rx_work {
81 	struct apple_rtkit *rtk;
82 	u8 ep;
83 	u64 msg;
84 	struct work_struct work;
85 };
86 
87 bool apple_rtkit_is_running(struct apple_rtkit *rtk)
88 {
89 	if (rtk->crashed)
90 		return false;
91 	if ((rtk->iop_power_state & 0xff) != APPLE_RTKIT_PWR_STATE_ON)
92 		return false;
93 	if ((rtk->ap_power_state & 0xff) != APPLE_RTKIT_PWR_STATE_ON)
94 		return false;
95 	return true;
96 }
97 EXPORT_SYMBOL_GPL(apple_rtkit_is_running);
98 
99 bool apple_rtkit_is_crashed(struct apple_rtkit *rtk)
100 {
101 	return rtk->crashed;
102 }
103 EXPORT_SYMBOL_GPL(apple_rtkit_is_crashed);
104 
105 static void apple_rtkit_management_send(struct apple_rtkit *rtk, u8 type,
106 					u64 msg)
107 {
108 	msg &= ~APPLE_RTKIT_MGMT_TYPE;
109 	msg |= FIELD_PREP(APPLE_RTKIT_MGMT_TYPE, type);
110 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_MGMT, msg, NULL, false);
111 }
112 
113 static void apple_rtkit_management_rx_hello(struct apple_rtkit *rtk, u64 msg)
114 {
115 	u64 reply;
116 
117 	int min_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MINVER, msg);
118 	int max_ver = FIELD_GET(APPLE_RTKIT_MGMT_HELLO_MAXVER, msg);
119 	int want_ver = min(APPLE_RTKIT_MAX_SUPPORTED_VERSION, max_ver);
120 
121 	dev_dbg(rtk->dev, "RTKit: Min ver %d, max ver %d\n", min_ver, max_ver);
122 
123 	if (min_ver > APPLE_RTKIT_MAX_SUPPORTED_VERSION) {
124 		dev_err(rtk->dev, "RTKit: Firmware min version %d is too new\n",
125 			min_ver);
126 		goto abort_boot;
127 	}
128 
129 	if (max_ver < APPLE_RTKIT_MIN_SUPPORTED_VERSION) {
130 		dev_err(rtk->dev, "RTKit: Firmware max version %d is too old\n",
131 			max_ver);
132 		goto abort_boot;
133 	}
134 
135 	dev_info(rtk->dev, "RTKit: Initializing (protocol version %d)\n",
136 		 want_ver);
137 	rtk->version = want_ver;
138 
139 	reply = FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MINVER, want_ver);
140 	reply |= FIELD_PREP(APPLE_RTKIT_MGMT_HELLO_MAXVER, want_ver);
141 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_HELLO_REPLY, reply);
142 
143 	return;
144 
145 abort_boot:
146 	rtk->boot_result = -EINVAL;
147 	complete_all(&rtk->epmap_completion);
148 }
149 
150 static void apple_rtkit_management_rx_epmap(struct apple_rtkit *rtk, u64 msg)
151 {
152 	int i, ep;
153 	u64 reply;
154 	unsigned long bitmap = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BITMAP, msg);
155 	u32 base = FIELD_GET(APPLE_RTKIT_MGMT_EPMAP_BASE, msg);
156 
157 	dev_dbg(rtk->dev,
158 		"RTKit: received endpoint bitmap 0x%lx with base 0x%x\n",
159 		bitmap, base);
160 
161 	for_each_set_bit(i, &bitmap, 32) {
162 		ep = 32 * base + i;
163 		dev_dbg(rtk->dev, "RTKit: Discovered endpoint 0x%02x\n", ep);
164 		set_bit(ep, rtk->endpoints);
165 	}
166 
167 	reply = FIELD_PREP(APPLE_RTKIT_MGMT_EPMAP_BASE, base);
168 	if (msg & APPLE_RTKIT_MGMT_EPMAP_LAST)
169 		reply |= APPLE_RTKIT_MGMT_EPMAP_LAST;
170 	else
171 		reply |= APPLE_RTKIT_MGMT_EPMAP_REPLY_MORE;
172 
173 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_EPMAP_REPLY, reply);
174 
175 	if (!(msg & APPLE_RTKIT_MGMT_EPMAP_LAST))
176 		return;
177 
178 	for_each_set_bit(ep, rtk->endpoints, APPLE_RTKIT_APP_ENDPOINT_START) {
179 		switch (ep) {
180 		/* the management endpoint is started by default */
181 		case APPLE_RTKIT_EP_MGMT:
182 			break;
183 
184 		/* without starting these RTKit refuses to boot */
185 		case APPLE_RTKIT_EP_SYSLOG:
186 		case APPLE_RTKIT_EP_CRASHLOG:
187 		case APPLE_RTKIT_EP_DEBUG:
188 		case APPLE_RTKIT_EP_IOREPORT:
189 		case APPLE_RTKIT_EP_OSLOG:
190 			dev_dbg(rtk->dev,
191 				"RTKit: Starting system endpoint 0x%02x\n", ep);
192 			apple_rtkit_start_ep(rtk, ep);
193 			break;
194 
195 		default:
196 			dev_warn(rtk->dev,
197 				 "RTKit: Unknown system endpoint: 0x%02x\n",
198 				 ep);
199 		}
200 	}
201 
202 	rtk->boot_result = 0;
203 	complete_all(&rtk->epmap_completion);
204 }
205 
206 static void apple_rtkit_management_rx_iop_pwr_ack(struct apple_rtkit *rtk,
207 						  u64 msg)
208 {
209 	unsigned int new_state = FIELD_GET(APPLE_RTKIT_MGMT_PWR_STATE, msg);
210 
211 	dev_dbg(rtk->dev, "RTKit: IOP power state transition: 0x%x -> 0x%x\n",
212 		rtk->iop_power_state, new_state);
213 	rtk->iop_power_state = new_state;
214 
215 	complete_all(&rtk->iop_pwr_ack_completion);
216 }
217 
218 static void apple_rtkit_management_rx_ap_pwr_ack(struct apple_rtkit *rtk,
219 						 u64 msg)
220 {
221 	unsigned int new_state = FIELD_GET(APPLE_RTKIT_MGMT_PWR_STATE, msg);
222 
223 	dev_dbg(rtk->dev, "RTKit: AP power state transition: 0x%x -> 0x%x\n",
224 		rtk->ap_power_state, new_state);
225 	rtk->ap_power_state = new_state;
226 
227 	complete_all(&rtk->ap_pwr_ack_completion);
228 }
229 
230 static void apple_rtkit_management_rx(struct apple_rtkit *rtk, u64 msg)
231 {
232 	u8 type = FIELD_GET(APPLE_RTKIT_MGMT_TYPE, msg);
233 
234 	switch (type) {
235 	case APPLE_RTKIT_MGMT_HELLO:
236 		apple_rtkit_management_rx_hello(rtk, msg);
237 		break;
238 	case APPLE_RTKIT_MGMT_EPMAP:
239 		apple_rtkit_management_rx_epmap(rtk, msg);
240 		break;
241 	case APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE_ACK:
242 		apple_rtkit_management_rx_iop_pwr_ack(rtk, msg);
243 		break;
244 	case APPLE_RTKIT_MGMT_SET_AP_PWR_STATE_ACK:
245 		apple_rtkit_management_rx_ap_pwr_ack(rtk, msg);
246 		break;
247 	default:
248 		dev_warn(
249 			rtk->dev,
250 			"RTKit: unknown management message: 0x%llx (type: 0x%02x)\n",
251 			msg, type);
252 	}
253 }
254 
255 static int apple_rtkit_common_rx_get_buffer(struct apple_rtkit *rtk,
256 					    struct apple_rtkit_shmem *buffer,
257 					    u8 ep, u64 msg)
258 {
259 	size_t n_4kpages = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_SIZE, msg);
260 	u64 reply;
261 	int err;
262 
263 	buffer->buffer = NULL;
264 	buffer->iomem = NULL;
265 	buffer->is_mapped = false;
266 	buffer->iova = FIELD_GET(APPLE_RTKIT_BUFFER_REQUEST_IOVA, msg);
267 	buffer->size = n_4kpages << 12;
268 
269 	dev_dbg(rtk->dev, "RTKit: buffer request for 0x%zx bytes at %pad\n",
270 		buffer->size, &buffer->iova);
271 
272 	if (buffer->iova &&
273 	    (!rtk->ops->shmem_setup || !rtk->ops->shmem_destroy)) {
274 		err = -EINVAL;
275 		goto error;
276 	}
277 
278 	if (rtk->ops->shmem_setup) {
279 		err = rtk->ops->shmem_setup(rtk->cookie, buffer);
280 		if (err)
281 			goto error;
282 	} else {
283 		buffer->buffer = dma_alloc_coherent(rtk->dev, buffer->size,
284 						    &buffer->iova, GFP_KERNEL);
285 		if (!buffer->buffer) {
286 			err = -ENOMEM;
287 			goto error;
288 		}
289 	}
290 
291 	if (!buffer->is_mapped) {
292 		reply = FIELD_PREP(APPLE_RTKIT_SYSLOG_TYPE,
293 				   APPLE_RTKIT_BUFFER_REQUEST);
294 		reply |= FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_SIZE, n_4kpages);
295 		reply |= FIELD_PREP(APPLE_RTKIT_BUFFER_REQUEST_IOVA,
296 				    buffer->iova);
297 		apple_rtkit_send_message(rtk, ep, reply, NULL, false);
298 	}
299 
300 	return 0;
301 
302 error:
303 	buffer->buffer = NULL;
304 	buffer->iomem = NULL;
305 	buffer->iova = 0;
306 	buffer->size = 0;
307 	buffer->is_mapped = false;
308 	return err;
309 }
310 
311 static void apple_rtkit_free_buffer(struct apple_rtkit *rtk,
312 				    struct apple_rtkit_shmem *bfr)
313 {
314 	if (bfr->size == 0)
315 		return;
316 
317 	if (rtk->ops->shmem_destroy)
318 		rtk->ops->shmem_destroy(rtk->cookie, bfr);
319 	else if (bfr->buffer)
320 		dma_free_coherent(rtk->dev, bfr->size, bfr->buffer, bfr->iova);
321 
322 	bfr->buffer = NULL;
323 	bfr->iomem = NULL;
324 	bfr->iova = 0;
325 	bfr->size = 0;
326 	bfr->is_mapped = false;
327 }
328 
329 static void apple_rtkit_memcpy(struct apple_rtkit *rtk, void *dst,
330 			       struct apple_rtkit_shmem *bfr, size_t offset,
331 			       size_t len)
332 {
333 	if (bfr->iomem)
334 		memcpy_fromio(dst, bfr->iomem + offset, len);
335 	else
336 		memcpy(dst, bfr->buffer + offset, len);
337 }
338 
339 static void apple_rtkit_crashlog_rx(struct apple_rtkit *rtk, u64 msg)
340 {
341 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
342 	u8 *bfr;
343 
344 	if (type != APPLE_RTKIT_CRASHLOG_CRASH) {
345 		dev_warn(rtk->dev, "RTKit: Unknown crashlog message: %llx\n",
346 			 msg);
347 		return;
348 	}
349 
350 	if (!rtk->crashlog_buffer.size) {
351 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->crashlog_buffer,
352 						 APPLE_RTKIT_EP_CRASHLOG, msg);
353 		return;
354 	}
355 
356 	dev_err(rtk->dev, "RTKit: co-processor has crashed\n");
357 
358 	/*
359 	 * create a shadow copy here to make sure the co-processor isn't able
360 	 * to change the log while we're dumping it. this also ensures
361 	 * the buffer is in normal memory and not iomem for e.g. the SMC
362 	 */
363 	bfr = kzalloc(rtk->crashlog_buffer.size, GFP_KERNEL);
364 	if (bfr) {
365 		apple_rtkit_memcpy(rtk, bfr, &rtk->crashlog_buffer, 0,
366 				   rtk->crashlog_buffer.size);
367 		apple_rtkit_crashlog_dump(rtk, bfr, rtk->crashlog_buffer.size);
368 		kfree(bfr);
369 	} else {
370 		dev_err(rtk->dev,
371 			"RTKit: Couldn't allocate crashlog shadow buffer\n");
372 	}
373 
374 	rtk->crashed = true;
375 	if (rtk->ops->crashed)
376 		rtk->ops->crashed(rtk->cookie);
377 }
378 
379 static void apple_rtkit_ioreport_rx(struct apple_rtkit *rtk, u64 msg)
380 {
381 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
382 
383 	switch (type) {
384 	case APPLE_RTKIT_BUFFER_REQUEST:
385 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->ioreport_buffer,
386 						 APPLE_RTKIT_EP_IOREPORT, msg);
387 		break;
388 	/* unknown, must be ACKed or the co-processor will hang */
389 	case 0x8:
390 	case 0xc:
391 		apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_IOREPORT, msg,
392 					 NULL, false);
393 		break;
394 	default:
395 		dev_warn(rtk->dev, "RTKit: Unknown ioreport message: %llx\n",
396 			 msg);
397 	}
398 }
399 
400 static void apple_rtkit_syslog_rx_init(struct apple_rtkit *rtk, u64 msg)
401 {
402 	rtk->syslog_n_entries = FIELD_GET(APPLE_RTKIT_SYSLOG_N_ENTRIES, msg);
403 	rtk->syslog_msg_size = FIELD_GET(APPLE_RTKIT_SYSLOG_MSG_SIZE, msg);
404 
405 	rtk->syslog_msg_buffer = kzalloc(rtk->syslog_msg_size, GFP_KERNEL);
406 
407 	dev_dbg(rtk->dev,
408 		"RTKit: syslog initialized: entries: %zd, msg_size: %zd\n",
409 		rtk->syslog_n_entries, rtk->syslog_msg_size);
410 }
411 
412 static bool should_crop_syslog_char(char c)
413 {
414 	return c == '\n' || c == '\r' || c == ' ' || c == '\0';
415 }
416 
417 static void apple_rtkit_syslog_rx_log(struct apple_rtkit *rtk, u64 msg)
418 {
419 	u8 idx = msg & 0xff;
420 	char log_context[24];
421 	size_t entry_size = 0x20 + rtk->syslog_msg_size;
422 	int msglen;
423 
424 	if (!rtk->syslog_msg_buffer) {
425 		dev_warn(
426 			rtk->dev,
427 			"RTKit: received syslog message but no syslog_msg_buffer\n");
428 		goto done;
429 	}
430 	if (!rtk->syslog_buffer.size) {
431 		dev_warn(
432 			rtk->dev,
433 			"RTKit: received syslog message but syslog_buffer.size is zero\n");
434 		goto done;
435 	}
436 	if (!rtk->syslog_buffer.buffer && !rtk->syslog_buffer.iomem) {
437 		dev_warn(
438 			rtk->dev,
439 			"RTKit: received syslog message but no syslog_buffer.buffer or syslog_buffer.iomem\n");
440 		goto done;
441 	}
442 	if (idx > rtk->syslog_n_entries) {
443 		dev_warn(rtk->dev, "RTKit: syslog index %d out of range\n",
444 			 idx);
445 		goto done;
446 	}
447 
448 	apple_rtkit_memcpy(rtk, log_context, &rtk->syslog_buffer,
449 			   idx * entry_size + 8, sizeof(log_context));
450 	apple_rtkit_memcpy(rtk, rtk->syslog_msg_buffer, &rtk->syslog_buffer,
451 			   idx * entry_size + 8 + sizeof(log_context),
452 			   rtk->syslog_msg_size);
453 
454 	log_context[sizeof(log_context) - 1] = 0;
455 
456 	msglen = rtk->syslog_msg_size - 1;
457 	while (msglen > 0 &&
458 		   should_crop_syslog_char(rtk->syslog_msg_buffer[msglen - 1]))
459 		msglen--;
460 
461 	rtk->syslog_msg_buffer[msglen] = 0;
462 	dev_info(rtk->dev, "RTKit: syslog message: %s: %s\n", log_context,
463 		 rtk->syslog_msg_buffer);
464 
465 done:
466 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_SYSLOG, msg, NULL, false);
467 }
468 
469 static void apple_rtkit_syslog_rx(struct apple_rtkit *rtk, u64 msg)
470 {
471 	u8 type = FIELD_GET(APPLE_RTKIT_SYSLOG_TYPE, msg);
472 
473 	switch (type) {
474 	case APPLE_RTKIT_BUFFER_REQUEST:
475 		apple_rtkit_common_rx_get_buffer(rtk, &rtk->syslog_buffer,
476 						 APPLE_RTKIT_EP_SYSLOG, msg);
477 		break;
478 	case APPLE_RTKIT_SYSLOG_INIT:
479 		apple_rtkit_syslog_rx_init(rtk, msg);
480 		break;
481 	case APPLE_RTKIT_SYSLOG_LOG:
482 		apple_rtkit_syslog_rx_log(rtk, msg);
483 		break;
484 	default:
485 		dev_warn(rtk->dev, "RTKit: Unknown syslog message: %llx\n",
486 			 msg);
487 	}
488 }
489 
490 static void apple_rtkit_oslog_rx_init(struct apple_rtkit *rtk, u64 msg)
491 {
492 	u64 ack;
493 
494 	dev_dbg(rtk->dev, "RTKit: oslog init: msg: 0x%llx\n", msg);
495 	ack = FIELD_PREP(APPLE_RTKIT_OSLOG_TYPE, APPLE_RTKIT_OSLOG_ACK);
496 	apple_rtkit_send_message(rtk, APPLE_RTKIT_EP_OSLOG, ack, NULL, false);
497 }
498 
499 static void apple_rtkit_oslog_rx(struct apple_rtkit *rtk, u64 msg)
500 {
501 	u8 type = FIELD_GET(APPLE_RTKIT_OSLOG_TYPE, msg);
502 
503 	switch (type) {
504 	case APPLE_RTKIT_OSLOG_INIT:
505 		apple_rtkit_oslog_rx_init(rtk, msg);
506 		break;
507 	default:
508 		dev_warn(rtk->dev, "RTKit: Unknown oslog message: %llx\n", msg);
509 	}
510 }
511 
512 static void apple_rtkit_rx_work(struct work_struct *work)
513 {
514 	struct apple_rtkit_rx_work *rtk_work =
515 		container_of(work, struct apple_rtkit_rx_work, work);
516 	struct apple_rtkit *rtk = rtk_work->rtk;
517 
518 	switch (rtk_work->ep) {
519 	case APPLE_RTKIT_EP_MGMT:
520 		apple_rtkit_management_rx(rtk, rtk_work->msg);
521 		break;
522 	case APPLE_RTKIT_EP_CRASHLOG:
523 		apple_rtkit_crashlog_rx(rtk, rtk_work->msg);
524 		break;
525 	case APPLE_RTKIT_EP_SYSLOG:
526 		apple_rtkit_syslog_rx(rtk, rtk_work->msg);
527 		break;
528 	case APPLE_RTKIT_EP_IOREPORT:
529 		apple_rtkit_ioreport_rx(rtk, rtk_work->msg);
530 		break;
531 	case APPLE_RTKIT_EP_OSLOG:
532 		apple_rtkit_oslog_rx(rtk, rtk_work->msg);
533 		break;
534 	case APPLE_RTKIT_APP_ENDPOINT_START ... 0xff:
535 		if (rtk->ops->recv_message)
536 			rtk->ops->recv_message(rtk->cookie, rtk_work->ep,
537 					       rtk_work->msg);
538 		else
539 			dev_warn(
540 				rtk->dev,
541 				"Received unexpected message to EP%02d: %llx\n",
542 				rtk_work->ep, rtk_work->msg);
543 		break;
544 	default:
545 		dev_warn(rtk->dev,
546 			 "RTKit: message to unknown endpoint %02x: %llx\n",
547 			 rtk_work->ep, rtk_work->msg);
548 	}
549 
550 	kfree(rtk_work);
551 }
552 
553 static void apple_rtkit_rx(struct mbox_client *cl, void *mssg)
554 {
555 	struct apple_rtkit *rtk = container_of(cl, struct apple_rtkit, mbox_cl);
556 	struct apple_mbox_msg *msg = mssg;
557 	struct apple_rtkit_rx_work *work;
558 	u8 ep = msg->msg1;
559 
560 	/*
561 	 * The message was read from a MMIO FIFO and we have to make
562 	 * sure all reads from buffers sent with that message happen
563 	 * afterwards.
564 	 */
565 	dma_rmb();
566 
567 	if (!test_bit(ep, rtk->endpoints))
568 		dev_warn(rtk->dev,
569 			 "RTKit: Message to undiscovered endpoint 0x%02x\n",
570 			 ep);
571 
572 	if (ep >= APPLE_RTKIT_APP_ENDPOINT_START &&
573 	    rtk->ops->recv_message_early &&
574 	    rtk->ops->recv_message_early(rtk->cookie, ep, msg->msg0))
575 		return;
576 
577 	work = kzalloc(sizeof(*work), GFP_ATOMIC);
578 	if (!work)
579 		return;
580 
581 	work->rtk = rtk;
582 	work->ep = ep;
583 	work->msg = msg->msg0;
584 	INIT_WORK(&work->work, apple_rtkit_rx_work);
585 	queue_work(rtk->wq, &work->work);
586 }
587 
588 static void apple_rtkit_tx_done(struct mbox_client *cl, void *mssg, int r)
589 {
590 	struct apple_rtkit_msg *msg =
591 		container_of(mssg, struct apple_rtkit_msg, mbox_msg);
592 
593 	if (r == -ETIME)
594 		return;
595 
596 	if (msg->completion)
597 		complete(msg->completion);
598 	kfree(msg);
599 }
600 
601 int apple_rtkit_send_message(struct apple_rtkit *rtk, u8 ep, u64 message,
602 			     struct completion *completion, bool atomic)
603 {
604 	struct apple_rtkit_msg *msg;
605 	int ret;
606 	gfp_t flags;
607 
608 	if (rtk->crashed)
609 		return -EINVAL;
610 	if (ep >= APPLE_RTKIT_APP_ENDPOINT_START &&
611 	    !apple_rtkit_is_running(rtk))
612 		return -EINVAL;
613 
614 	if (atomic)
615 		flags = GFP_ATOMIC;
616 	else
617 		flags = GFP_KERNEL;
618 
619 	msg = kzalloc(sizeof(*msg), flags);
620 	if (!msg)
621 		return -ENOMEM;
622 
623 	msg->mbox_msg.msg0 = message;
624 	msg->mbox_msg.msg1 = ep;
625 	msg->completion = completion;
626 
627 	/*
628 	 * The message will be sent with a MMIO write. We need the barrier
629 	 * here to ensure any previous writes to buffers are visible to the
630 	 * device before that MMIO write happens.
631 	 */
632 	dma_wmb();
633 
634 	ret = mbox_send_message(rtk->mbox_chan, &msg->mbox_msg);
635 	if (ret < 0) {
636 		kfree(msg);
637 		return ret;
638 	}
639 
640 	return 0;
641 }
642 EXPORT_SYMBOL_GPL(apple_rtkit_send_message);
643 
644 int apple_rtkit_send_message_wait(struct apple_rtkit *rtk, u8 ep, u64 message,
645 				  unsigned long timeout, bool atomic)
646 {
647 	DECLARE_COMPLETION_ONSTACK(completion);
648 	int ret;
649 	long t;
650 
651 	ret = apple_rtkit_send_message(rtk, ep, message, &completion, atomic);
652 	if (ret < 0)
653 		return ret;
654 
655 	if (atomic) {
656 		ret = mbox_flush(rtk->mbox_chan, timeout);
657 		if (ret < 0)
658 			return ret;
659 
660 		if (try_wait_for_completion(&completion))
661 			return 0;
662 
663 		return -ETIME;
664 	} else {
665 		t = wait_for_completion_interruptible_timeout(
666 			&completion, msecs_to_jiffies(timeout));
667 		if (t < 0)
668 			return t;
669 		else if (t == 0)
670 			return -ETIME;
671 		return 0;
672 	}
673 }
674 EXPORT_SYMBOL_GPL(apple_rtkit_send_message_wait);
675 
676 int apple_rtkit_poll(struct apple_rtkit *rtk)
677 {
678 	return mbox_client_peek_data(rtk->mbox_chan);
679 }
680 EXPORT_SYMBOL_GPL(apple_rtkit_poll);
681 
682 int apple_rtkit_start_ep(struct apple_rtkit *rtk, u8 endpoint)
683 {
684 	u64 msg;
685 
686 	if (!test_bit(endpoint, rtk->endpoints))
687 		return -EINVAL;
688 	if (endpoint >= APPLE_RTKIT_APP_ENDPOINT_START &&
689 	    !apple_rtkit_is_running(rtk))
690 		return -EINVAL;
691 
692 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_STARTEP_EP, endpoint);
693 	msg |= APPLE_RTKIT_MGMT_STARTEP_FLAG;
694 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_STARTEP, msg);
695 
696 	return 0;
697 }
698 EXPORT_SYMBOL_GPL(apple_rtkit_start_ep);
699 
700 static int apple_rtkit_request_mbox_chan(struct apple_rtkit *rtk)
701 {
702 	if (rtk->mbox_name)
703 		rtk->mbox_chan = mbox_request_channel_byname(&rtk->mbox_cl,
704 							     rtk->mbox_name);
705 	else
706 		rtk->mbox_chan =
707 			mbox_request_channel(&rtk->mbox_cl, rtk->mbox_idx);
708 
709 	if (IS_ERR(rtk->mbox_chan))
710 		return PTR_ERR(rtk->mbox_chan);
711 	return 0;
712 }
713 
714 struct apple_rtkit *apple_rtkit_init(struct device *dev, void *cookie,
715 					    const char *mbox_name, int mbox_idx,
716 					    const struct apple_rtkit_ops *ops)
717 {
718 	struct apple_rtkit *rtk;
719 	int ret;
720 
721 	if (!ops)
722 		return ERR_PTR(-EINVAL);
723 
724 	rtk = kzalloc(sizeof(*rtk), GFP_KERNEL);
725 	if (!rtk)
726 		return ERR_PTR(-ENOMEM);
727 
728 	rtk->dev = dev;
729 	rtk->cookie = cookie;
730 	rtk->ops = ops;
731 
732 	init_completion(&rtk->epmap_completion);
733 	init_completion(&rtk->iop_pwr_ack_completion);
734 	init_completion(&rtk->ap_pwr_ack_completion);
735 
736 	bitmap_zero(rtk->endpoints, APPLE_RTKIT_MAX_ENDPOINTS);
737 	set_bit(APPLE_RTKIT_EP_MGMT, rtk->endpoints);
738 
739 	rtk->mbox_name = mbox_name;
740 	rtk->mbox_idx = mbox_idx;
741 	rtk->mbox_cl.dev = dev;
742 	rtk->mbox_cl.tx_block = false;
743 	rtk->mbox_cl.knows_txdone = false;
744 	rtk->mbox_cl.rx_callback = &apple_rtkit_rx;
745 	rtk->mbox_cl.tx_done = &apple_rtkit_tx_done;
746 
747 	rtk->wq = alloc_ordered_workqueue("rtkit-%s", WQ_MEM_RECLAIM,
748 					  dev_name(rtk->dev));
749 	if (!rtk->wq) {
750 		ret = -ENOMEM;
751 		goto free_rtk;
752 	}
753 
754 	ret = apple_rtkit_request_mbox_chan(rtk);
755 	if (ret)
756 		goto destroy_wq;
757 
758 	return rtk;
759 
760 destroy_wq:
761 	destroy_workqueue(rtk->wq);
762 free_rtk:
763 	kfree(rtk);
764 	return ERR_PTR(ret);
765 }
766 EXPORT_SYMBOL_GPL(apple_rtkit_init);
767 
768 static int apple_rtkit_wait_for_completion(struct completion *c)
769 {
770 	long t;
771 
772 	t = wait_for_completion_interruptible_timeout(c,
773 						      msecs_to_jiffies(1000));
774 	if (t < 0)
775 		return t;
776 	else if (t == 0)
777 		return -ETIME;
778 	else
779 		return 0;
780 }
781 
782 int apple_rtkit_reinit(struct apple_rtkit *rtk)
783 {
784 	/* make sure we don't handle any messages while reinitializing */
785 	mbox_free_channel(rtk->mbox_chan);
786 	flush_workqueue(rtk->wq);
787 
788 	apple_rtkit_free_buffer(rtk, &rtk->ioreport_buffer);
789 	apple_rtkit_free_buffer(rtk, &rtk->crashlog_buffer);
790 	apple_rtkit_free_buffer(rtk, &rtk->syslog_buffer);
791 
792 	kfree(rtk->syslog_msg_buffer);
793 
794 	rtk->syslog_msg_buffer = NULL;
795 	rtk->syslog_n_entries = 0;
796 	rtk->syslog_msg_size = 0;
797 
798 	bitmap_zero(rtk->endpoints, APPLE_RTKIT_MAX_ENDPOINTS);
799 	set_bit(APPLE_RTKIT_EP_MGMT, rtk->endpoints);
800 
801 	reinit_completion(&rtk->epmap_completion);
802 	reinit_completion(&rtk->iop_pwr_ack_completion);
803 	reinit_completion(&rtk->ap_pwr_ack_completion);
804 
805 	rtk->crashed = false;
806 	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_OFF;
807 	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_OFF;
808 
809 	return apple_rtkit_request_mbox_chan(rtk);
810 }
811 EXPORT_SYMBOL_GPL(apple_rtkit_reinit);
812 
813 static int apple_rtkit_set_ap_power_state(struct apple_rtkit *rtk,
814 					  unsigned int state)
815 {
816 	u64 msg;
817 	int ret;
818 
819 	reinit_completion(&rtk->ap_pwr_ack_completion);
820 
821 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, state);
822 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_AP_PWR_STATE,
823 				    msg);
824 
825 	ret = apple_rtkit_wait_for_completion(&rtk->ap_pwr_ack_completion);
826 	if (ret)
827 		return ret;
828 
829 	if (rtk->ap_power_state != state)
830 		return -EINVAL;
831 	return 0;
832 }
833 
834 static int apple_rtkit_set_iop_power_state(struct apple_rtkit *rtk,
835 					   unsigned int state)
836 {
837 	u64 msg;
838 	int ret;
839 
840 	reinit_completion(&rtk->iop_pwr_ack_completion);
841 
842 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, state);
843 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE,
844 				    msg);
845 
846 	ret = apple_rtkit_wait_for_completion(&rtk->iop_pwr_ack_completion);
847 	if (ret)
848 		return ret;
849 
850 	if (rtk->iop_power_state != state)
851 		return -EINVAL;
852 	return 0;
853 }
854 
855 int apple_rtkit_boot(struct apple_rtkit *rtk)
856 {
857 	int ret;
858 
859 	if (apple_rtkit_is_running(rtk))
860 		return 0;
861 	if (rtk->crashed)
862 		return -EINVAL;
863 
864 	dev_dbg(rtk->dev, "RTKit: waiting for boot to finish\n");
865 	ret = apple_rtkit_wait_for_completion(&rtk->epmap_completion);
866 	if (ret)
867 		return ret;
868 	if (rtk->boot_result)
869 		return rtk->boot_result;
870 
871 	dev_dbg(rtk->dev, "RTKit: waiting for IOP power state ACK\n");
872 	ret = apple_rtkit_wait_for_completion(&rtk->iop_pwr_ack_completion);
873 	if (ret)
874 		return ret;
875 
876 	return apple_rtkit_set_ap_power_state(rtk, APPLE_RTKIT_PWR_STATE_ON);
877 }
878 EXPORT_SYMBOL_GPL(apple_rtkit_boot);
879 
880 int apple_rtkit_shutdown(struct apple_rtkit *rtk)
881 {
882 	int ret;
883 
884 	/* if OFF is used here the co-processor will not wake up again */
885 	ret = apple_rtkit_set_ap_power_state(rtk,
886 					     APPLE_RTKIT_PWR_STATE_QUIESCED);
887 	if (ret)
888 		return ret;
889 
890 	ret = apple_rtkit_set_iop_power_state(rtk, APPLE_RTKIT_PWR_STATE_SLEEP);
891 	if (ret)
892 		return ret;
893 
894 	return apple_rtkit_reinit(rtk);
895 }
896 EXPORT_SYMBOL_GPL(apple_rtkit_shutdown);
897 
898 int apple_rtkit_idle(struct apple_rtkit *rtk)
899 {
900 	int ret;
901 
902 	/* if OFF is used here the co-processor will not wake up again */
903 	ret = apple_rtkit_set_ap_power_state(rtk,
904 					     APPLE_RTKIT_PWR_STATE_IDLE);
905 	if (ret)
906 		return ret;
907 
908 	ret = apple_rtkit_set_iop_power_state(rtk, APPLE_RTKIT_PWR_STATE_IDLE);
909 	if (ret)
910 		return ret;
911 
912 	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_IDLE;
913 	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_IDLE;
914 	return 0;
915 }
916 EXPORT_SYMBOL_GPL(apple_rtkit_idle);
917 
918 int apple_rtkit_quiesce(struct apple_rtkit *rtk)
919 {
920 	int ret;
921 
922 	ret = apple_rtkit_set_ap_power_state(rtk,
923 					     APPLE_RTKIT_PWR_STATE_QUIESCED);
924 	if (ret)
925 		return ret;
926 
927 	ret = apple_rtkit_set_iop_power_state(rtk,
928 					      APPLE_RTKIT_PWR_STATE_QUIESCED);
929 	if (ret)
930 		return ret;
931 
932 	ret = apple_rtkit_reinit(rtk);
933 	if (ret)
934 		return ret;
935 
936 	rtk->iop_power_state = APPLE_RTKIT_PWR_STATE_QUIESCED;
937 	rtk->ap_power_state = APPLE_RTKIT_PWR_STATE_QUIESCED;
938 	return 0;
939 }
940 EXPORT_SYMBOL_GPL(apple_rtkit_quiesce);
941 
942 int apple_rtkit_wake(struct apple_rtkit *rtk)
943 {
944 	u64 msg;
945 
946 	if (apple_rtkit_is_running(rtk))
947 		return -EINVAL;
948 
949 	reinit_completion(&rtk->iop_pwr_ack_completion);
950 
951 	/*
952 	 * Use open-coded apple_rtkit_set_iop_power_state since apple_rtkit_boot
953 	 * will wait for the completion anyway.
954 	 */
955 	msg = FIELD_PREP(APPLE_RTKIT_MGMT_PWR_STATE, APPLE_RTKIT_PWR_STATE_ON);
956 	apple_rtkit_management_send(rtk, APPLE_RTKIT_MGMT_SET_IOP_PWR_STATE,
957 				    msg);
958 
959 	return apple_rtkit_boot(rtk);
960 }
961 EXPORT_SYMBOL_GPL(apple_rtkit_wake);
962 
963 void apple_rtkit_free(struct apple_rtkit *rtk)
964 {
965 	mbox_free_channel(rtk->mbox_chan);
966 	destroy_workqueue(rtk->wq);
967 
968 	apple_rtkit_free_buffer(rtk, &rtk->ioreport_buffer);
969 	apple_rtkit_free_buffer(rtk, &rtk->crashlog_buffer);
970 	apple_rtkit_free_buffer(rtk, &rtk->syslog_buffer);
971 
972 	kfree(rtk->syslog_msg_buffer);
973 	kfree(rtk);
974 }
975 EXPORT_SYMBOL_GPL(apple_rtkit_free);
976 
977 static void apple_rtkit_free_wrapper(void *data)
978 {
979 	apple_rtkit_free(data);
980 }
981 
982 struct apple_rtkit *devm_apple_rtkit_init(struct device *dev, void *cookie,
983 					  const char *mbox_name, int mbox_idx,
984 					  const struct apple_rtkit_ops *ops)
985 {
986 	struct apple_rtkit *rtk;
987 	int ret;
988 
989 	rtk = apple_rtkit_init(dev, cookie, mbox_name, mbox_idx, ops);
990 	if (IS_ERR(rtk))
991 		return rtk;
992 
993 	ret = devm_add_action_or_reset(dev, apple_rtkit_free_wrapper, rtk);
994 	if (ret)
995 		return ERR_PTR(ret);
996 
997 	return rtk;
998 }
999 EXPORT_SYMBOL_GPL(devm_apple_rtkit_init);
1000 
1001 MODULE_LICENSE("Dual MIT/GPL");
1002 MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
1003 MODULE_DESCRIPTION("Apple RTKit driver");
1004