1 // SPDX-License-Identifier: Apache-2.0
2 // Copyright (C) 2018 IBM Corp.
3
4 #define _GNU_SOURCE
5 #include <assert.h>
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <getopt.h>
9 #include <limits.h>
10 #include <poll.h>
11 #include <stdbool.h>
12 #include <stdint.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <syslog.h>
17 #include <signal.h>
18 #include <sys/ioctl.h>
19 #include <sys/mman.h>
20 #include <sys/stat.h>
21 #include <sys/timerfd.h>
22 #include <sys/types.h>
23 #include <time.h>
24 #include <unistd.h>
25 #include <inttypes.h>
26
27 #include "mbox.h"
28 #include "common.h"
29 #include "mboxd_msg.h"
30 #include "mboxd_windows.h"
31 #include "mboxd_lpc.h"
32
33 /*
34 * write_bmc_event_reg() - Write to the BMC controlled status register (reg 15)
35 * @context: The mbox context pointer
36 *
37 * Return: 0 on success otherwise negative error code
38 */
write_bmc_event_reg(struct mbox_context * context)39 static int write_bmc_event_reg(struct mbox_context *context)
40 {
41 int rc;
42
43 /* Seek mbox registers */
44 rc = lseek(context->fds[MBOX_FD].fd, MBOX_BMC_EVENT, SEEK_SET);
45 if (rc != MBOX_BMC_EVENT) {
46 MSG_ERR("Couldn't lseek mbox to byte %d: %s\n", MBOX_BMC_EVENT,
47 strerror(errno));
48 return -MBOX_R_SYSTEM_ERROR;
49 }
50
51 /* Write to mbox status register */
52 rc = write(context->fds[MBOX_FD].fd, &context->bmc_events, 1);
53 if (rc != 1) {
54 MSG_ERR("Couldn't write to BMC status reg: %s\n",
55 strerror(errno));
56 return -MBOX_R_SYSTEM_ERROR;
57 }
58
59 /* Reset to start */
60 rc = lseek(context->fds[MBOX_FD].fd, 0, SEEK_SET);
61 if (rc) {
62 MSG_ERR("Couldn't reset MBOX offset to zero: %s\n",
63 strerror(errno));
64 return -MBOX_R_SYSTEM_ERROR;
65 }
66
67 return 0;
68 }
69
70 /*
71 * set_bmc_events() - Set BMC events
72 * @context: The mbox context pointer
73 * @bmc_event: The bits to set
74 * @write_back: Whether to write back to the register -> will interrupt host
75 *
76 * Return: 0 on success otherwise negative error code
77 */
set_bmc_events(struct mbox_context * context,uint8_t bmc_event,bool write_back)78 int set_bmc_events(struct mbox_context *context, uint8_t bmc_event,
79 bool write_back)
80 {
81 uint8_t mask = 0x00;
82
83 switch (context->version) {
84 case API_VERSION_1:
85 mask = BMC_EVENT_V1_MASK;
86 break;
87 default:
88 mask = BMC_EVENT_V2_MASK;
89 break;
90 }
91
92 context->bmc_events |= (bmc_event & mask);
93 MSG_DBG("BMC Events set to: 0x%.2x\n", context->bmc_events);
94
95 return write_back ? write_bmc_event_reg(context) : 0;
96 }
97
98 /*
99 * clr_bmc_events() - Clear BMC events
100 * @context: The mbox context pointer
101 * @bmc_event: The bits to clear
102 * @write_back: Whether to write back to the register -> will interrupt host
103 *
104 * Return: 0 on success otherwise negative error code
105 */
clr_bmc_events(struct mbox_context * context,uint8_t bmc_event,bool write_back)106 int clr_bmc_events(struct mbox_context *context, uint8_t bmc_event,
107 bool write_back)
108 {
109 context->bmc_events &= ~bmc_event;
110 MSG_DBG("BMC Events clear to: 0x%.2x\n", context->bmc_events);
111
112 return write_back ? write_bmc_event_reg(context) : 0;
113 }
114
115 /* Command Handlers */
116
117 /*
118 * Command: RESET_STATE
119 * Reset the LPC mapping to point back at the flash, or memory in case we're
120 * using a virtual pnor.
121 */
mbox_handle_reset(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)122 int mbox_handle_reset(struct mbox_context *context,
123 union mbox_regs *req, struct mbox_msg *resp)
124 {
125 /* Host requested it -> No BMC Event */
126 reset_all_windows(context, NO_BMC_EVENT);
127 return reset_lpc(context);
128 }
129
130 /*
131 * get_suggested_timeout() - get the suggested timeout value in seconds
132 * @context: The mbox context pointer
133 *
134 * Return: Suggested timeout in seconds
135 */
get_suggested_timeout(struct mbox_context * context)136 static uint16_t get_suggested_timeout(struct mbox_context *context)
137 {
138 struct window_context *window = find_largest_window(context);
139 uint32_t max_size_mb = window ? (window->size >> 20) : 0;
140 uint16_t ret;
141
142 ret = align_up(max_size_mb * FLASH_ACCESS_MS_PER_MB, 1000) / 1000;
143
144 MSG_DBG("Suggested Timeout: %us, max window size: %uMB, for %dms/MB\n",
145 ret, max_size_mb, FLASH_ACCESS_MS_PER_MB);
146 return ret;
147 }
148
149 /*
150 * Command: GET_MBOX_INFO
151 * Get the API version, default window size and block size
152 * We also set the LPC mapping to point to the reserved memory region here so
153 * this command must be called before any window manipulation
154 *
155 * V1:
156 * ARGS[0]: API Version
157 *
158 * RESP[0]: API Version
159 * RESP[1:2]: Default read window size (number of blocks)
160 * RESP[3:4]: Default write window size (number of blocks)
161 * RESP[5]: Block size (as shift)
162 *
163 * V2:
164 * ARGS[0]: API Version
165 *
166 * RESP[0]: API Version
167 * RESP[1:2]: Default read window size (number of blocks)
168 * RESP[3:4]: Default write window size (number of blocks)
169 * RESP[5]: Block size (as shift)
170 */
mbox_handle_mbox_info(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)171 int mbox_handle_mbox_info(struct mbox_context *context,
172 union mbox_regs *req, struct mbox_msg *resp)
173 {
174 uint8_t mbox_api_version = req->msg.args[0];
175 uint8_t old_api_version = context->version;
176 int rc;
177
178 /* Check we support the version requested */
179 if (mbox_api_version < API_MIN_VERSION)
180 return -MBOX_R_PARAM_ERROR;
181
182 if (mbox_api_version > API_MAX_VERSION)
183 mbox_api_version = API_MAX_VERSION;
184
185 context->version = mbox_api_version;
186 MSG_INFO("Using Protocol Version: %d\n", context->version);
187
188 /*
189 * The reset state is currently to have the LPC bus point directly to
190 * flash, since we got a mbox_info command we know the host can talk
191 * mbox so point the LPC bus mapping to the reserved memory region now
192 * so the host can access what we put in it.
193 */
194 rc = point_to_memory(context);
195 if (rc < 0) {
196 return rc;
197 }
198
199 switch (context->version) {
200 case API_VERSION_1:
201 context->block_size_shift = BLOCK_SIZE_SHIFT_V1;
202 break;
203 default:
204 context->block_size_shift = log_2(context->mtd_info.erasesize);
205 break;
206 }
207 MSG_INFO("Block Size: 0x%.8x (shift: %u)\n",
208 1 << context->block_size_shift, context->block_size_shift);
209
210 /* Now we know the blocksize we can allocate the window dirty_bytemap */
211 if (mbox_api_version != old_api_version) {
212 alloc_window_dirty_bytemap(context);
213 }
214 /* Reset if we were V1 since this required exact window mapping */
215 if (old_api_version == API_VERSION_1) {
216 /*
217 * This will only set the BMC event if there was a current
218 * window -> In which case we are better off notifying the
219 * host.
220 */
221 reset_all_windows(context, SET_BMC_EVENT);
222 }
223
224 resp->args[0] = mbox_api_version;
225 if (context->version == API_VERSION_1) {
226 put_u16(&resp->args[1], context->windows.default_size >>
227 context->block_size_shift);
228 put_u16(&resp->args[3], context->windows.default_size >>
229 context->block_size_shift);
230 }
231 if (context->version >= API_VERSION_2) {
232 resp->args[5] = context->block_size_shift;
233 put_u16(&resp->args[6], get_suggested_timeout(context));
234 }
235
236 return 0;
237 }
238
239 /*
240 * Command: GET_FLASH_INFO
241 * Get the flash size and erase granularity
242 *
243 * V1:
244 * RESP[0:3]: Flash Size (bytes)
245 * RESP[4:7]: Erase Size (bytes)
246 * V2:
247 * RESP[0:1]: Flash Size (number of blocks)
248 * RESP[2:3]: Erase Size (number of blocks)
249 */
mbox_handle_flash_info(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)250 int mbox_handle_flash_info(struct mbox_context *context,
251 union mbox_regs *req, struct mbox_msg *resp)
252 {
253 switch (context->version) {
254 case API_VERSION_1:
255 /* Both Sizes in Bytes */
256 put_u32(&resp->args[0], context->flash_size);
257 put_u32(&resp->args[4], context->mtd_info.erasesize);
258 break;
259 case API_VERSION_2:
260 /* Both Sizes in Block Size */
261 put_u16(&resp->args[0],
262 context->flash_size >> context->block_size_shift);
263 put_u16(&resp->args[2],
264 context->mtd_info.erasesize >>
265 context->block_size_shift);
266 break;
267 default:
268 MSG_ERR("API Version Not Valid - Invalid System State\n");
269 return -MBOX_R_SYSTEM_ERROR;
270 }
271
272 return 0;
273 }
274
275 /*
276 * get_lpc_addr_shifted() - Get lpc address of the current window
277 * @context: The mbox context pointer
278 *
279 * Return: The lpc address to access that offset shifted by block size
280 */
get_lpc_addr_shifted(struct mbox_context * context)281 static inline uint16_t get_lpc_addr_shifted(struct mbox_context *context)
282 {
283 uint32_t lpc_addr, mem_offset;
284
285 /* Offset of the current window in the reserved memory region */
286 mem_offset = context->current->mem - context->mem;
287 /* Total LPC Address */
288 lpc_addr = context->lpc_base + mem_offset;
289
290 MSG_DBG("LPC address of current window: 0x%.8x\n", lpc_addr);
291
292 return lpc_addr >> context->block_size_shift;
293 }
294
295 /*
296 * Command: CREATE_READ_WINDOW
297 * Opens a read window
298 * First checks if any current window with the requested data, if so we just
299 * point the host to that. Otherwise we read the request data in from flash and
300 * point the host there.
301 *
302 * V1:
303 * ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
304 *
305 * RESP[0:1]: LPC bus address for host to access this window (number of blocks)
306 *
307 * V2:
308 * ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
309 * ARGS[2:3]: Requested window size (number of blocks)
310 *
311 * RESP[0:1]: LPC bus address for host to access this window (number of blocks)
312 * RESP[2:3]: Actual window size that the host can access (number of blocks)
313 */
mbox_handle_read_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)314 int mbox_handle_read_window(struct mbox_context *context,
315 union mbox_regs *req, struct mbox_msg *resp)
316 {
317 uint32_t flash_offset;
318 int rc;
319
320 /* Close the current window if there is one */
321 if (context->current) {
322 /* There is an implicit flush if it was a write window */
323 if (context->current_is_write) {
324 rc = mbox_handle_flush_window(context, NULL, NULL);
325 if (rc < 0) {
326 MSG_ERR("Couldn't Flush Write Window\n");
327 return rc;
328 }
329 }
330 close_current_window(context, NO_BMC_EVENT, FLAGS_NONE);
331 }
332
333 /* Offset the host has requested */
334 flash_offset = get_u16(&req->msg.args[0]) << context->block_size_shift;
335 MSG_INFO("Host requested flash @ 0x%.8x\n", flash_offset);
336 /* Check if we have an existing window */
337 context->current = search_windows(context, flash_offset,
338 context->version == API_VERSION_1);
339
340 if (!context->current) { /* No existing window */
341 MSG_DBG("No existing window which maps that flash offset\n");
342 rc = create_map_window(context, &context->current, flash_offset,
343 context->version == API_VERSION_1);
344 if (rc < 0) { /* Unable to map offset */
345 MSG_ERR("Couldn't create window mapping for offset 0x%.8x\n"
346 , flash_offset);
347 return rc;
348 }
349 }
350
351 MSG_INFO("Window @ %p for size 0x%.8x maps flash offset 0x%.8x\n",
352 context->current->mem, context->current->size,
353 context->current->flash_offset);
354
355 put_u16(&resp->args[0], get_lpc_addr_shifted(context));
356 if (context->version >= API_VERSION_2) {
357 put_u16(&resp->args[2], context->current->size >>
358 context->block_size_shift);
359 put_u16(&resp->args[4], context->current->flash_offset >>
360 context->block_size_shift);
361 }
362
363 context->current_is_write = false;
364
365 return 0;
366 }
367
368 /*
369 * Command: CREATE_WRITE_WINDOW
370 * Opens a write window
371 * First checks if any current window with the requested data, if so we just
372 * point the host to that. Otherwise we read the request data in from flash and
373 * point the host there.
374 *
375 * V1:
376 * ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
377 *
378 * RESP[0:1]: LPC bus address for host to access this window (number of blocks)
379 *
380 * V2:
381 * ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
382 * ARGS[2:3]: Requested window size (number of blocks)
383 *
384 * RESP[0:1]: LPC bus address for host to access this window (number of blocks)
385 * RESP[2:3]: Actual window size that was mapped/host can access (n.o. blocks)
386 */
mbox_handle_write_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)387 int mbox_handle_write_window(struct mbox_context *context,
388 union mbox_regs *req, struct mbox_msg *resp)
389 {
390 int rc;
391
392 /*
393 * This is very similar to opening a read window (exactly the same
394 * for now infact)
395 */
396 rc = mbox_handle_read_window(context, req, resp);
397 if (rc < 0) {
398 return rc;
399 }
400
401 context->current_is_write = true;
402 return rc;
403 }
404
405 /*
406 * Commands: MARK_WRITE_DIRTY
407 * Marks a portion of the current (write) window dirty, informing the daemon
408 * that is has been written to and thus must be at some point written to the
409 * backing store
410 * These changes aren't written back to the backing store unless flush is then
411 * called or the window closed
412 *
413 * V1:
414 * ARGS[0:1]: Where within flash to start (number of blocks)
415 * ARGS[2:5]: Number to mark dirty (number of bytes)
416 *
417 * V2:
418 * ARGS[0:1]: Where within window to start (number of blocks)
419 * ARGS[2:3]: Number to mark dirty (number of blocks)
420 */
mbox_handle_dirty_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)421 int mbox_handle_dirty_window(struct mbox_context *context,
422 union mbox_regs *req, struct mbox_msg *resp)
423 {
424 uint32_t offset, size;
425
426 if (!(context->current && context->current_is_write)) {
427 MSG_ERR("Tried to call mark dirty without open write window\n");
428 return context->version >= API_VERSION_2 ? -MBOX_R_WINDOW_ERROR
429 : -MBOX_R_PARAM_ERROR;
430 }
431
432 offset = get_u16(&req->msg.args[0]);
433
434 if (context->version >= API_VERSION_2) {
435 size = get_u16(&req->msg.args[2]);
436 } else {
437 uint32_t off;
438 /* For V1 offset given relative to flash - we want the window */
439 off = offset - ((context->current->flash_offset) >>
440 context->block_size_shift);
441 if (off > offset) { /* Underflow - before current window */
442 MSG_ERR("Tried to mark dirty before start of window\n");
443 MSG_ERR("requested offset: 0x%x window start: 0x%x\n",
444 offset << context->block_size_shift,
445 context->current->flash_offset);
446 return -MBOX_R_PARAM_ERROR;
447 }
448 offset = off;
449 size = get_u32(&req->msg.args[2]);
450 /*
451 * We only track dirty at the block level.
452 * For protocol V1 we can get away with just marking the whole
453 * block dirty.
454 */
455 size = align_up(size, 1 << context->block_size_shift);
456 size >>= context->block_size_shift;
457 }
458
459 MSG_INFO("Dirty window @ 0x%.8x for 0x%.8x\n",
460 offset << context->block_size_shift,
461 size << context->block_size_shift);
462
463 return set_window_bytemap(context, context->current, offset, size,
464 WINDOW_DIRTY);
465 }
466
467 /*
468 * Commands: MARK_WRITE_ERASE
469 * Erases a portion of the current window
470 * These changes aren't written back to the backing store unless flush is then
471 * called or the window closed
472 *
473 * V1:
474 * Unimplemented
475 *
476 * V2:
477 * ARGS[0:1]: Where within window to start (number of blocks)
478 * ARGS[2:3]: Number to erase (number of blocks)
479 */
mbox_handle_erase_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)480 int mbox_handle_erase_window(struct mbox_context *context,
481 union mbox_regs *req, struct mbox_msg *resp)
482 {
483 uint32_t offset, size;
484 int rc;
485
486 if (context->version < API_VERSION_2) {
487 MSG_ERR("Protocol Version invalid for Erase Command\n");
488 return -MBOX_R_PARAM_ERROR;
489 }
490
491 if (!(context->current && context->current_is_write)) {
492 MSG_ERR("Tried to call erase without open write window\n");
493 return -MBOX_R_WINDOW_ERROR;
494 }
495
496 offset = get_u16(&req->msg.args[0]);
497 size = get_u16(&req->msg.args[2]);
498
499 MSG_INFO("Erase window @ 0x%.8x for 0x%.8x\n",
500 offset << context->block_size_shift,
501 size << context->block_size_shift);
502
503 rc = set_window_bytemap(context, context->current, offset, size,
504 WINDOW_ERASED);
505 if (rc < 0) {
506 return rc;
507 }
508
509 /* Write 0xFF to mem -> This ensures consistency between flash & ram */
510 memset(context->current->mem + (offset << context->block_size_shift),
511 0xFF, size << context->block_size_shift);
512
513 return 0;
514 }
515
516 /*
517 * Command: WRITE_FLUSH
518 * Flushes any dirty or erased blocks in the current window back to the backing
519 * store
520 * NOTE: For V1 this behaves much the same as the dirty command in that it
521 * takes an offset and number of blocks to dirty, then also performs a flush as
522 * part of the same command. For V2 this will only flush blocks already marked
523 * dirty/erased with the appropriate commands and doesn't take any arguments
524 * directly.
525 *
526 * V1:
527 * ARGS[0:1]: Where within window to start (number of blocks)
528 * ARGS[2:5]: Number to mark dirty (number of bytes)
529 *
530 * V2:
531 * NONE
532 */
mbox_handle_flush_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)533 int mbox_handle_flush_window(struct mbox_context *context,
534 union mbox_regs *req, struct mbox_msg *resp)
535 {
536 int rc, i, offset, count;
537 uint8_t prev;
538
539 if (!(context->current && context->current_is_write)) {
540 MSG_ERR("Tried to call flush without open write window\n");
541 return context->version >= API_VERSION_2 ? -MBOX_R_WINDOW_ERROR
542 : -MBOX_R_PARAM_ERROR;
543 }
544
545 /*
546 * For V1 the Flush command acts much the same as the dirty command
547 * except with a flush as well. Only do this on an actual flush
548 * command not when we call flush because we've implicitly closed a
549 * window because we might not have the required args in req.
550 */
551 if (context->version == API_VERSION_1 && req &&
552 req->msg.command == MBOX_C_WRITE_FLUSH) {
553 rc = mbox_handle_dirty_window(context, req, NULL);
554 if (rc < 0) {
555 return rc;
556 }
557 }
558
559 offset = 0;
560 count = 0;
561 prev = WINDOW_CLEAN;
562
563 MSG_INFO("Flush window @ %p for size 0x%.8x which maps flash @ 0x%.8x\n",
564 context->current->mem, context->current->size,
565 context->current->flash_offset);
566
567 /*
568 * We look for streaks of the same type and keep a count, when the type
569 * (dirty/erased) changes we perform the required action on the backing
570 * store and update the current streak-type
571 */
572 for (i = 0; i < (context->current->size >> context->block_size_shift);
573 i++) {
574 uint8_t cur = context->current->dirty_bmap[i];
575 if (cur != WINDOW_CLEAN) {
576 if (cur == prev) { /* Same as previous block, incrmnt */
577 count++;
578 } else if (prev == WINDOW_CLEAN) { /* Start of run */
579 offset = i;
580 count++;
581 } else { /* Change in streak type */
582 rc = write_from_window(context, offset, count,
583 prev);
584 if (rc < 0) {
585 return rc;
586 }
587 offset = i;
588 count = 1;
589 }
590 } else {
591 if (prev != WINDOW_CLEAN) { /* End of a streak */
592 rc = write_from_window(context, offset, count,
593 prev);
594 if (rc < 0) {
595 return rc;
596 }
597 offset = 0;
598 count = 0;
599 }
600 }
601 prev = cur;
602 }
603
604 if (prev != WINDOW_CLEAN) { /* Still the last streak to write */
605 rc = write_from_window(context, offset, count, prev);
606 if (rc < 0) {
607 return rc;
608 }
609 }
610
611 /* Clear the dirty bytemap since we have written back all changes */
612 return set_window_bytemap(context, context->current, 0,
613 context->current->size >>
614 context->block_size_shift,
615 WINDOW_CLEAN);
616 }
617
618 /*
619 * Command: CLOSE_WINDOW
620 * Close the current window
621 * NOTE: There is an implicit flush
622 *
623 * V1:
624 * NONE
625 *
626 * V2:
627 * ARGS[0]: FLAGS
628 */
mbox_handle_close_window(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)629 int mbox_handle_close_window(struct mbox_context *context,
630 union mbox_regs *req, struct mbox_msg *resp)
631 {
632 uint8_t flags = 0;
633 int rc;
634
635 /* Close the current window if there is one */
636 if (context->current) {
637 /* There is an implicit flush if it was a write window */
638 if (context->current_is_write) {
639 rc = mbox_handle_flush_window(context, NULL, NULL);
640 if (rc < 0) {
641 MSG_ERR("Couldn't Flush Write Window\n");
642 return rc;
643 }
644 }
645
646 if (context->version >= API_VERSION_2) {
647 flags = req->msg.args[0];
648 }
649
650 /* Host asked for it -> Don't set the BMC Event */
651 close_current_window(context, NO_BMC_EVENT, flags);
652 }
653
654 return 0;
655 }
656
657 /*
658 * Command: BMC_EVENT_ACK
659 * Sent by the host to acknowledge BMC events supplied in mailbox register 15
660 *
661 * ARGS[0]: Bitmap of bits to ack (by clearing)
662 */
mbox_handle_ack(struct mbox_context * context,union mbox_regs * req,struct mbox_msg * resp)663 int mbox_handle_ack(struct mbox_context *context, union mbox_regs *req,
664 struct mbox_msg *resp)
665 {
666 uint8_t bmc_events = req->msg.args[0];
667
668 return clr_bmc_events(context, (bmc_events & BMC_EVENT_ACK_MASK),
669 SET_BMC_EVENT);
670 }
671
672 /*
673 * check_req_valid() - Check if the given request is a valid mbox request
674 * @context: The mbox context pointer
675 * @cmd: The request registers
676 *
677 * Return: 0 if request is valid otherwise negative error code
678 */
check_req_valid(struct mbox_context * context,union mbox_regs * req)679 static int check_req_valid(struct mbox_context *context, union mbox_regs *req)
680 {
681 uint8_t cmd = req->msg.command;
682 uint8_t seq = req->msg.seq;
683
684 if (cmd > NUM_MBOX_CMDS) {
685 MSG_ERR("Unknown mbox command: %d\n", cmd);
686 return -MBOX_R_PARAM_ERROR;
687 }
688
689 if (seq == context->prev_seq && cmd != MBOX_C_GET_MBOX_INFO) {
690 MSG_ERR("Invalid sequence number: %d, previous: %d\n", seq,
691 context->prev_seq);
692 return -MBOX_R_SEQ_ERROR;
693 }
694
695 if (context->state & STATE_SUSPENDED) {
696 if (cmd != MBOX_C_GET_MBOX_INFO && cmd != MBOX_C_ACK) {
697 MSG_ERR("Cannot use that cmd while suspended: %d\n",
698 cmd);
699 return context->version >= API_VERSION_2 ? -MBOX_R_BUSY
700 : -MBOX_R_PARAM_ERROR;
701 }
702 }
703
704 if (!(context->state & MAPS_MEM)) {
705 if (cmd != MBOX_C_RESET_STATE && cmd != MBOX_C_GET_MBOX_INFO
706 && cmd != MBOX_C_ACK) {
707 MSG_ERR("Must call GET_MBOX_INFO before %d\n", cmd);
708 return -MBOX_R_PARAM_ERROR;
709 }
710 }
711
712 return 0;
713 }
714
715 static const mboxd_mbox_handler mbox_handlers[] = {
716 mbox_handle_reset,
717 mbox_handle_mbox_info,
718 mbox_handle_flash_info,
719 mbox_handle_read_window,
720 mbox_handle_close_window,
721 mbox_handle_write_window,
722 mbox_handle_dirty_window,
723 mbox_handle_flush_window,
724 mbox_handle_ack,
725 mbox_handle_erase_window
726 };
727
728 /*
729 * handle_mbox_req() - Handle an incoming mbox command request
730 * @context: The mbox context pointer
731 * @req: The mbox request message
732 *
733 * Return: 0 if handled successfully otherwise negative error code
734 */
handle_mbox_req(struct mbox_context * context,union mbox_regs * req)735 static int handle_mbox_req(struct mbox_context *context, union mbox_regs *req)
736 {
737 struct mbox_msg resp = {
738 .command = req->msg.command,
739 .seq = req->msg.seq,
740 .args = { 0 },
741 .response = MBOX_R_SUCCESS
742 };
743 int rc = 0, len, i;
744
745 MSG_INFO("Received MBOX command: %u\n", req->msg.command);
746 rc = check_req_valid(context, req);
747 if (rc < 0) {
748 resp.response = -rc;
749 } else {
750 /* Commands start at 1 so we have to subtract 1 from the cmd */
751 mboxd_mbox_handler h = context->handlers[req->msg.command - 1];
752 rc = h(context, req, &resp);
753 if (rc < 0) {
754 MSG_ERR("Error handling mbox cmd: %d\n",
755 req->msg.command);
756 resp.response = -rc;
757 }
758 }
759
760 context->prev_seq = req->msg.seq;
761
762 MSG_DBG("Writing MBOX response:\n");
763 MSG_DBG("MBOX cmd: %u\n", resp.command);
764 MSG_DBG("MBOX seq: %u\n", resp.seq);
765 for (i = 0; i < MBOX_ARGS_BYTES; i++) {
766 MSG_DBG("MBOX arg[%d]: 0x%.2x\n", i, resp.args[i]);
767 }
768 MSG_INFO("Writing MBOX response: %u\n", resp.response);
769 len = write(context->fds[MBOX_FD].fd, &resp, sizeof(resp));
770 if (len < sizeof(resp)) {
771 MSG_ERR("Didn't write the full response\n");
772 rc = -errno;
773 }
774
775 return rc;
776 }
777
778 /*
779 * get_message() - Read an mbox request message from the mbox registers
780 * @context: The mbox context pointer
781 * @msg: Where to put the received message
782 *
783 * Return: 0 if read successfully otherwise negative error code
784 */
get_message(struct mbox_context * context,union mbox_regs * msg)785 static int get_message(struct mbox_context *context, union mbox_regs *msg)
786 {
787 int rc, i;
788
789 rc = read(context->fds[MBOX_FD].fd, msg, sizeof(msg->raw));
790 if (rc < 0) {
791 MSG_ERR("Couldn't read: %s\n", strerror(errno));
792 return -errno;
793 } else if (rc < sizeof(msg->raw)) {
794 MSG_ERR("Short read: %d expecting %zu\n", rc, sizeof(msg->raw));
795 return -1;
796 }
797
798 MSG_DBG("Received MBOX request:\n");
799 MSG_DBG("MBOX cmd: %u\n", msg->msg.command);
800 MSG_DBG("MBOX seq: %u\n", msg->msg.seq);
801 for (i = 0; i < MBOX_ARGS_BYTES; i++) {
802 MSG_DBG("MBOX arg[%d]: 0x%.2x\n", i, msg->msg.args[i]);
803 }
804
805 return 0;
806 }
807
808 /*
809 * dispatch_mbox() - handle an mbox interrupt
810 * @context: The mbox context pointer
811 *
812 * Return: 0 if handled successfully otherwise negative error code
813 */
dispatch_mbox(struct mbox_context * context)814 int dispatch_mbox(struct mbox_context *context)
815 {
816 int rc = 0;
817 union mbox_regs req = { 0 };
818
819 assert(context);
820
821 rc = get_message(context, &req);
822 if (rc) {
823 return rc;
824 }
825
826 return handle_mbox_req(context, &req);
827 }
828
__init_mbox_dev(struct mbox_context * context,const char * path)829 int __init_mbox_dev(struct mbox_context *context, const char *path)
830 {
831 int fd;
832
833 context->handlers = mbox_handlers;
834
835 /* Open MBOX Device */
836 fd = open(path, O_RDWR | O_NONBLOCK);
837 if (fd < 0) {
838 MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n",
839 path, strerror(errno));
840 return -errno;
841 }
842 MSG_DBG("Opened mbox dev: %s\n", path);
843
844 context->fds[MBOX_FD].fd = fd;
845
846 return 0;
847 }
848
init_mbox_dev(struct mbox_context * context)849 int init_mbox_dev(struct mbox_context *context)
850 {
851 return __init_mbox_dev(context, MBOX_HOST_PATH);
852 }
853
free_mbox_dev(struct mbox_context * context)854 void free_mbox_dev(struct mbox_context *context)
855 {
856 close(context->fds[MBOX_FD].fd);
857 }
858