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Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +11001/*
2 * Mailbox Daemon Window Helpers
3 *
4 * Copyright 2016 IBM
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 *
18 */
19
20#define _GNU_SOURCE
21#include <assert.h>
22#include <errno.h>
23#include <fcntl.h>
24#include <getopt.h>
25#include <limits.h>
26#include <poll.h>
27#include <stdbool.h>
28#include <stdint.h>
29#include <stdio.h>
30#include <stdlib.h>
31#include <string.h>
32#include <syslog.h>
33#include <signal.h>
34#include <sys/ioctl.h>
35#include <sys/mman.h>
36#include <sys/stat.h>
37#include <sys/timerfd.h>
38#include <sys/types.h>
39#include <time.h>
40#include <unistd.h>
41#include <inttypes.h>
42#include <mtd/mtd-abi.h>
43
44#include "mbox.h"
45#include "common.h"
46#include "mboxd_msg.h"
47#include "mboxd_windows.h"
48#include "mboxd_flash.h"
49
50/* Initialisation Functions */
51
52/*
53 * init_window_state() - Initialise a new window to a known state
54 * @window: The window to initialise
55 * @size: The size of the window
56 */
Suraj Jitindar Singhc29172e2017-04-12 14:26:47 +100057static void init_window_state(struct window_context *window, uint32_t size)
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +110058{
59 window->mem = NULL;
60 window->flash_offset = FLASH_OFFSET_UNINIT;
61 window->size = size;
62 window->dirty_bmap = NULL;
63 window->age = 0;
64}
65
66/*
67 * init_window_mem() - Divide the reserved memory region among the windows
68 * @context: The mbox context pointer
69 *
70 * Return: 0 on success otherwise negative error code
71 */
Suraj Jitindar Singhc29172e2017-04-12 14:26:47 +100072static int init_window_mem(struct mbox_context *context)
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +110073{
74 void *mem_location = context->mem;
75 int i;
76
77 /*
78 * Carve up the reserved memory region and allocate it to each of the
79 * windows. The windows are placed one after the other in ascending
80 * order, so the first window will be first in memory and so on. We
81 * shouldn't have allocated more windows than we have memory, but if we
82 * did we will error out here
83 */
84 for (i = 0; i < context->windows.num; i++) {
Suraj Jitindar Singh28519592017-04-27 14:48:58 +100085 uint32_t size = context->windows.window[i].size;
86 MSG_DBG("Window %d @ %p for size 0x%.8x\n", i,
87 mem_location, size);
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +110088 context->windows.window[i].mem = mem_location;
Suraj Jitindar Singh28519592017-04-27 14:48:58 +100089 mem_location += size;
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +110090 if (mem_location > (context->mem + context->mem_size)) {
91 /* Tried to allocate window past the end of memory */
92 MSG_ERR("Total size of windows exceeds reserved mem\n");
93 MSG_ERR("Try smaller or fewer windows\n");
94 MSG_ERR("Mem size: 0x%.8x\n", context->mem_size);
95 return -1;
96 }
97 }
98
99 return 0;
100}
Suraj Jitindar Singhc29172e2017-04-12 14:26:47 +1000101/*
102 * init_windows() - Initalise the window cache
103 * @context: The mbox context pointer
104 *
105 * Return: 0 on success otherwise negative
106 */
107int init_windows(struct mbox_context *context)
108{
109 int i;
110
111 /* Check if window size and number set - otherwise set to default */
112 if (!context->windows.default_size) {
113 /* Default to 1MB windows */
114 context->windows.default_size = 1 << 20;
115 }
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000116 MSG_INFO("Window size: 0x%.8x\n", context->windows.default_size);
Suraj Jitindar Singhc29172e2017-04-12 14:26:47 +1000117 if (!context->windows.num) {
118 /* Use the entire reserved memory region by default */
119 context->windows.num = context->mem_size /
120 context->windows.default_size;
121 }
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000122 MSG_INFO("Number of windows: %d\n", context->windows.num);
Suraj Jitindar Singhc29172e2017-04-12 14:26:47 +1000123
124 context->windows.window = calloc(context->windows.num,
125 sizeof(*context->windows.window));
126 if (!context->windows.window) {
127 MSG_ERR("Memory allocation failed\n");
128 return -1;
129 }
130
131 for (i = 0; i < context->windows.num; i++) {
132 init_window_state(&context->windows.window[i],
133 context->windows.default_size);
134 }
135
136 return init_window_mem(context);
137}
138
139/*
140 * free_windows() - Free the window cache
141 * @context: The mbox context pointer
142 */
143void free_windows(struct mbox_context *context)
144{
145 int i;
146
147 /* Check window cache has actually been allocated */
148 if (context->windows.window) {
149 for (i = 0; i < context->windows.num; i++) {
150 free(context->windows.window[i].dirty_bmap);
151 }
152 free(context->windows.window);
153 }
154}
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100155
156/* Write from Window Functions */
157
158/*
159 * write_from_window_v1() - Handle writing when erase and block size differ
160 * @context: The mbox context pointer
161 * @offset_bytes: The offset in the current window to write from (bytes)
162 * @count_bytes: Number of bytes to write
163 *
164 * Handle a write_from_window for dirty memory when block_size is less than the
165 * flash erase size
166 * This requires us to be a bit careful because we might have to erase more
167 * than we want to write which could result in data loss if we don't have the
168 * entire portion of flash to be erased already saved in memory (for us to
169 * write back after the erase)
170 *
171 * Return: 0 on success otherwise negative error code
172 */
173int write_from_window_v1(struct mbox_context *context,
174 uint32_t offset_bytes, uint32_t count_bytes)
175{
176 int rc;
177 uint32_t flash_offset;
178 struct window_context low_mem = { 0 }, high_mem = { 0 };
179
180 /* Find where in phys flash this is based on the window.flash_offset */
181 flash_offset = context->current->flash_offset + offset_bytes;
182
183 /*
184 * low_mem.flash_offset = erase boundary below where we're writing
185 * low_mem.size = size from low_mem.flash_offset to where we're writing
186 *
187 * high_mem.flash_offset = end of where we're writing
188 * high_mem.size = size from end of where we're writing to next erase
189 * boundary
190 */
191 low_mem.flash_offset = align_down(flash_offset,
192 context->mtd_info.erasesize);
193 low_mem.size = flash_offset - low_mem.flash_offset;
194 high_mem.flash_offset = flash_offset + count_bytes;
195 high_mem.size = align_up(high_mem.flash_offset,
196 context->mtd_info.erasesize) -
197 high_mem.flash_offset;
198
199 /*
200 * Check if we already have a copy of the required flash areas in
201 * memory as part of the existing window
202 */
203 if (low_mem.flash_offset < context->current->flash_offset) {
204 /* Before the start of our current window */
205 low_mem.mem = malloc(low_mem.size);
206 if (!low_mem.mem) {
207 MSG_ERR("Unable to allocate memory\n");
208 return -MBOX_R_SYSTEM_ERROR;
209 }
210 rc = copy_flash(context, low_mem.flash_offset,
211 low_mem.mem, low_mem.size);
212 if (rc < 0) {
213 goto out;
214 }
215 }
216 if ((high_mem.flash_offset + high_mem.size) >
217 (context->current->flash_offset + context->current->size)) {
218 /* After the end of our current window */
219 high_mem.mem = malloc(high_mem.size);
220 if (!high_mem.mem) {
221 MSG_ERR("Unable to allocate memory\n");
222 rc = -MBOX_R_SYSTEM_ERROR;
223 goto out;
224 }
225 rc = copy_flash(context, high_mem.flash_offset,
226 high_mem.mem, high_mem.size);
227 if (rc < 0) {
228 goto out;
229 }
230 }
231
232 /*
233 * We need to erase the flash from low_mem.flash_offset->
234 * high_mem.flash_offset + high_mem.size
235 */
236 rc = erase_flash(context, low_mem.flash_offset,
237 (high_mem.flash_offset - low_mem.flash_offset) +
238 high_mem.size);
239 if (rc < 0) {
240 MSG_ERR("Couldn't erase flash\n");
241 goto out;
242 }
243
244 /* Write back over the erased area */
245 if (low_mem.mem) {
246 /* Exceed window at the start */
247 rc = write_flash(context, low_mem.flash_offset, low_mem.mem,
248 low_mem.size);
249 if (rc < 0) {
250 goto out;
251 }
252 }
253 rc = write_flash(context, flash_offset,
254 context->current->mem + offset_bytes, count_bytes);
255 if (rc < 0) {
256 goto out;
257 }
258 /*
259 * We still need to write the last little bit that we erased - it's
260 * either in the current window or the high_mem window.
261 */
262 if (high_mem.mem) {
263 /* Exceed window at the end */
264 rc = write_flash(context, high_mem.flash_offset, high_mem.mem,
265 high_mem.size);
266 if (rc < 0) {
267 goto out;
268 }
269 } else {
270 /* Write from the current window - it's atleast that big */
271 rc = write_flash(context, high_mem.flash_offset,
272 context->current->mem + offset_bytes +
273 count_bytes, high_mem.size);
274 if (rc < 0) {
275 goto out;
276 }
277 }
278
279out:
280 free(low_mem.mem);
281 free(high_mem.mem);
282 return rc;
283}
284
285/*
286 * write_from_window() - Write back to the flash from the current window
287 * @context: The mbox context pointer
288 * @offset_bytes: The offset in the current window to write from (blocks)
289 * @count_bytes: Number of blocks to write
290 * @type: Whether this is an erase & write or just an erase
291 *
292 * Return: 0 on success otherwise negative error code
293 */
294int write_from_window(struct mbox_context *context, uint32_t offset,
295 uint32_t count, uint8_t type)
296{
297 int rc;
298 uint32_t flash_offset, count_bytes = count << context->block_size_shift;
299 uint32_t offset_bytes = offset << context->block_size_shift;
300
301 switch (type) {
302 case WINDOW_ERASED: /* >= V2 ONLY -> block_size == erasesize */
303 flash_offset = context->current->flash_offset + offset_bytes;
304 rc = erase_flash(context, flash_offset, count_bytes);
305 if (rc < 0) {
306 MSG_ERR("Couldn't erase flash\n");
307 return rc;
308 }
309 break;
310 case WINDOW_DIRTY:
311 /*
312 * For protocol V1, block_size may be smaller than erase size
313 * so we have a special function to make sure that we do this
314 * correctly without losing data.
315 */
316 if (log_2(context->mtd_info.erasesize) !=
317 context->block_size_shift) {
318 return write_from_window_v1(context, offset_bytes,
319 count_bytes);
320 }
321 flash_offset = context->current->flash_offset + offset_bytes;
322
323 /* Erase the flash */
324 rc = erase_flash(context, flash_offset, count_bytes);
325 if (rc < 0) {
326 return rc;
327 }
328
329 /* Write to the erased flash */
330 rc = write_flash(context, flash_offset,
331 context->current->mem + offset_bytes,
332 count_bytes);
333 if (rc < 0) {
334 return rc;
335 }
336
337 break;
338 default:
339 /* We shouldn't be able to get here */
340 MSG_ERR("Write from window with invalid type: %d\n", type);
341 return -MBOX_R_SYSTEM_ERROR;
342 }
343
344 return 0;
345}
346
347/* Window Management Functions */
348
349/*
350 * alloc_window_dirty_bytemap() - (re)allocate all the window dirty bytemaps
351 * @context: The mbox context pointer
352 */
353void alloc_window_dirty_bytemap(struct mbox_context *context)
354{
355 struct window_context *cur;
356 int i;
357
358 for (i = 0; i < context->windows.num; i++) {
359 cur = &context->windows.window[i];
360 /* There may already be one allocated */
361 free(cur->dirty_bmap);
362 /* Allocate the new one */
363 cur->dirty_bmap = calloc((cur->size >>
364 context->block_size_shift),
365 sizeof(*cur->dirty_bmap));
366 }
367}
368
369/*
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100370 * set_window_bytemap() - Set the window bytemap
371 * @context: The mbox context pointer
372 * @cur: The window to set the bytemap of
373 * @offset: Where in the window to set the bytemap (blocks)
374 * @size: The number of blocks to set
375 * @val: The value to set the bytemap to
376 *
377 * Return: 0 on success otherwise negative error code
378 */
379int set_window_bytemap(struct mbox_context *context, struct window_context *cur,
380 uint32_t offset, uint32_t size, uint8_t val)
381{
382 if (offset + size > (cur->size >> context->block_size_shift)) {
383 MSG_ERR("Tried to set window bytemap past end of window\n");
384 MSG_ERR("Requested offset: 0x%x size: 0x%x window size: 0x%x\n",
385 offset << context->block_size_shift,
386 size << context->block_size_shift,
387 cur->size << context->block_size_shift);
388 return -MBOX_R_PARAM_ERROR;
389 }
390
391 memset(cur->dirty_bmap + offset, val, size);
392 return 0;
393}
394
395/*
396 * close_current_window() - Close the current (active) window
397 * @context: The mbox context pointer
398 * @set_bmc_event: Whether to set the bmc event bit
399 * @flags: Flags as defined for a close command in the protocol
400 *
401 * This closes the current window. If the host has requested the current window
402 * be closed then we don't need to set the bmc event bit
403 * (set_bmc_event == false), otherwise if the current window has been closed
404 * without the host requesting it the bmc event bit must be set to indicate this
405 * to the host (set_bmc_event == true).
406 */
407void close_current_window(struct mbox_context *context, bool set_bmc_event,
408 uint8_t flags)
409{
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000410 MSG_DBG("Close current window, flags: 0x%.2x\n", flags);
411
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100412 if (set_bmc_event) {
413 set_bmc_events(context, BMC_EVENT_WINDOW_RESET, SET_BMC_EVENT);
414 }
415
416 if (flags & FLAGS_SHORT_LIFETIME) {
417 context->current->age = 0;
418 }
419
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100420 context->current = NULL;
421 context->current_is_write = false;
422}
423
424/*
425 * reset_window() - Reset a window context to a well defined default state
426 * @context: The mbox context pointer
427 * @window: The window to reset
428 */
429void reset_window(struct mbox_context *context, struct window_context *window)
430{
431 window->flash_offset = FLASH_OFFSET_UNINIT;
432 window->size = context->windows.default_size;
433 if (window->dirty_bmap) { /* Might not have been allocated */
434 set_window_bytemap(context, window, 0,
435 window->size >> context->block_size_shift,
436 WINDOW_CLEAN);
437 }
438 window->age = 0;
439}
440
441/*
442 * reset_all_windows() - Reset all windows to a well defined default state
443 * @context: The mbox context pointer
444 * @set_bmc_event: If any state change should be indicated to the host
445 */
446void reset_all_windows(struct mbox_context *context, bool set_bmc_event)
447{
448 int i;
449
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000450 MSG_DBG("Resetting all windows\n");
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100451 /* We might have an open window which needs closing */
452 if (context->current) {
453 close_current_window(context, set_bmc_event, FLAGS_NONE);
454 }
455 for (i = 0; i < context->windows.num; i++) {
456 reset_window(context, &context->windows.window[i]);
457 }
458
459 context->windows.max_age = 0;
460}
461
462/*
463 * find_oldest_window() - Find the oldest (Least Recently Used) window
464 * @context: The mbox context pointer
465 *
466 * Return: Pointer to the least recently used window
467 */
468struct window_context *find_oldest_window(struct mbox_context *context)
469{
470 struct window_context *oldest = NULL, *cur;
471 uint32_t min_age = context->windows.max_age + 1;
472 int i;
473
474 for (i = 0; i < context->windows.num; i++) {
475 cur = &context->windows.window[i];
476
477 if (cur->age < min_age) {
478 min_age = cur->age;
479 oldest = cur;
480 }
481 }
482
483 return oldest;
484}
485
486/*
Suraj Jitindar Singh5a3a0662017-04-27 11:55:26 +1000487 * find_largest_window() - Find the largest window in the window cache
488 * @context: The mbox context pointer
489 *
490 * Return: The largest window
491 */
492struct window_context *find_largest_window(struct mbox_context *context)
493{
494 struct window_context *largest = NULL, *cur;
495 uint32_t max_size = 0;
496 int i;
497
498 for (i = 0; i < context->windows.num; i++) {
499 cur = &context->windows.window[i];
500
501 if (cur->size > max_size) {
502 max_size = cur->size;
503 largest = cur;
504 }
505 }
506
507 return largest;
508}
509
510/*
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100511 * search_windows() - Search the window cache for a window containing offset
512 * @context: The mbox context pointer
513 * @offset: Absolute flash offset to search for (bytes)
514 * @exact: If the window must exactly map the requested offset
515 *
516 * This will search the cache of windows for one containing the requested
517 * offset. For V1 of the protocol windows must exactly map the offset since we
518 * can't tell the host how much of its request we actually mapped and it will
519 * thus assume it can access window->size from the offset we give it.
520 *
521 * Return: Pointer to a window containing the requested offset otherwise
522 * NULL
523 */
524struct window_context *search_windows(struct mbox_context *context,
525 uint32_t offset, bool exact)
526{
527 struct window_context *cur;
528 int i;
529
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000530 MSG_DBG("Searching for window which contains 0x%.8x %s\n",
531 offset, exact ? "exactly" : "");
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100532 for (i = 0; i < context->windows.num; i++) {
533 cur = &context->windows.window[i];
534 if (cur->flash_offset == FLASH_OFFSET_UNINIT) {
535 /* Uninitialised Window */
536 if (offset == FLASH_OFFSET_UNINIT) {
537 return cur;
538 }
539 continue;
540 }
541 if ((offset >= cur->flash_offset) &&
542 (offset < (cur->flash_offset + cur->size))) {
543 if (exact && (cur->flash_offset != offset)) {
544 continue;
545 }
546 /* This window contains the requested offset */
547 cur->age = ++(context->windows.max_age);
548 return cur;
549 }
550 }
551
552 return NULL;
553}
554
555/*
556 * create_map_window() - Create a window mapping which maps the requested offset
557 * @context: The mbox context pointer
558 * @this_window: A pointer to update to the "new" window
559 * @offset: Absolute flash offset to create a mapping for (bytes)
560 * @exact: If the window must exactly map the requested offset
561 *
562 * This is used to create a window mapping for the requested offset when there
563 * is no existing window in the cache which satisfies the offset. This involves
564 * choosing an existing window from the window cache to evict so we can use it
565 * to store the flash contents from the requested offset, we then point the
566 * caller to that window since it now maps their request.
567 *
568 * Return: 0 on success otherwise negative error code
569 */
570int create_map_window(struct mbox_context *context,
571 struct window_context **this_window, uint32_t offset,
572 bool exact)
573{
574 struct window_context *cur = NULL;
575 int rc;
576
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000577 MSG_DBG("Creating window which maps 0x%.8x %s\n", offset,
578 exact ? "exactly" : "");
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100579
580 /* Search for an uninitialised window, use this before evicting */
581 cur = search_windows(context, FLASH_OFFSET_UNINIT, true);
582
583 /* No uninitialised window found, we need to choose one to "evict" */
584 if (!cur) {
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000585 MSG_DBG("No uninitialised window, evicting one\n");
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100586 cur = find_oldest_window(context);
587 }
588
Deepak Kodihalliaee73892017-07-12 13:18:06 -0500589/*
590 * In case of the virtual pnor, as of now it's possible that a window may
591 * have content less than it's max size. We basically copy one flash partition
592 * per window, and some partitions are smaller than the max size. An offset
593 * right after such a small partition ends should lead to new mapping. The code
594 * below prevents that.
595 */
596#ifndef VIRTUAL_PNOR_ENABLED
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100597 if (!exact) {
598 /*
599 * It would be nice to align the offsets which we map to window
600 * size, this will help prevent overlap which would be an
601 * inefficient use of our reserved memory area (we would like
602 * to "cache" as much of the acutal flash as possible in
603 * memory). If we're protocol V1 however we must ensure the
604 * offset requested is exactly mapped.
605 */
606 offset &= ~(cur->size - 1);
607 }
Deepak Kodihalliaee73892017-07-12 13:18:06 -0500608#endif
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100609
610 if ((offset + cur->size) > context->flash_size) {
611 /*
612 * There is V1 skiboot implementations out there which don't
613 * mask offset with window size, meaning when we have
614 * window size == flash size we will never allow the host to
615 * open a window except at 0x0, which isn't always where the
616 * host requests it. Thus we have to ignore this check and just
617 * hope the host doesn't access past the end of the window
618 * (which it shouldn't) for V1 implementations to get around
619 * this.
620 */
621 if (context->version == API_VERSION_1) {
622 cur->size = align_down(context->flash_size - offset,
623 1 << context->block_size_shift);
624 } else {
625 /* Trying to read past the end of flash */
626 MSG_ERR("Tried to open read window past flash limit\n");
627 return -MBOX_R_PARAM_ERROR;
628 }
629 }
630
631 /* Copy from flash into the window buffer */
632 rc = copy_flash(context, offset, cur->mem, cur->size);
633 if (rc < 0) {
634 /* We don't know how much we've copied -> better reset window */
635 reset_window(context, cur);
636 return rc;
637 }
Deepak Kodihalli7ee307c2017-07-12 03:41:08 -0500638 cur->size = rc;
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100639
640 /*
641 * Since for V1 windows aren't constrained to start at multiples of
642 * window size it's possible that something already maps this offset.
643 * Reset any windows which map this offset to avoid coherency problems.
644 * We just have to check for anything which maps the start or the end
645 * of the window since all windows are the same size so another window
646 * cannot map just the middle of this window.
647 */
648 if (context->version == API_VERSION_1) {
649 uint32_t i;
650
Suraj Jitindar Singh28519592017-04-27 14:48:58 +1000651 MSG_DBG("Checking for window overlap\n");
652
Suraj Jitindar Singhe39c9162017-03-28 10:47:43 +1100653 for (i = offset; i < (offset + cur->size); i += (cur->size - 1)) {
654 struct window_context *tmp = NULL;
655 do {
656 tmp = search_windows(context, i, false);
657 if (tmp) {
658 reset_window(context, tmp);
659 }
660 } while (tmp);
661 }
662 }
663
664 /* Clear the bytemap of the window just loaded -> we know it's clean */
665 set_window_bytemap(context, cur, 0,
666 cur->size >> context->block_size_shift,
667 WINDOW_CLEAN);
668
669 /* Update so we know what's in the window */
670 cur->flash_offset = offset;
671 cur->age = ++(context->windows.max_age);
672 *this_window = cur;
673
674 return 0;
675}