1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * RAM Oops/Panic logger
4 *
5 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
6 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/err.h>
13#include <linux/module.h>
14#include <linux/version.h>
15#include <linux/pstore.h>
16#include <linux/io.h>
17#include <linux/ioport.h>
18#include <linux/platform_device.h>
19#include <linux/slab.h>
20#include <linux/compiler.h>
21#include <linux/of.h>
22#include <linux/of_address.h>
23#include <linux/mm.h>
24
25#include "internal.h"
26#include "ram_internal.h"
27
28#define RAMOOPS_KERNMSG_HDR "===="
29#define MIN_MEM_SIZE 4096UL
30
31static ulong record_size = MIN_MEM_SIZE;
32module_param(record_size, ulong, 0400);
33MODULE_PARM_DESC(record_size,
34 "size of each dump done on oops/panic");
35
36static ulong ramoops_console_size = MIN_MEM_SIZE;
37module_param_named(console_size, ramoops_console_size, ulong, 0400);
38MODULE_PARM_DESC(console_size, "size of kernel console log");
39
40static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
41module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
42MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
43
44static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
45module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
46MODULE_PARM_DESC(pmsg_size, "size of user space message log");
47
48static unsigned long long mem_address;
49module_param_hw(mem_address, ullong, other, 0400);
50MODULE_PARM_DESC(mem_address,
51 "start of reserved RAM used to store oops/panic logs");
52
53static ulong mem_size;
54module_param(mem_size, ulong, 0400);
55MODULE_PARM_DESC(mem_size,
56 "size of reserved RAM used to store oops/panic logs");
57
58static unsigned int mem_type;
59module_param(mem_type, uint, 0400);
60MODULE_PARM_DESC(mem_type,
61 "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
62
63static int ramoops_max_reason = -1;
64module_param_named(max_reason, ramoops_max_reason, int, 0400);
65MODULE_PARM_DESC(max_reason,
66 "maximum reason for kmsg dump (default 2: Oops and Panic) ");
67
68static int ramoops_ecc;
69module_param_named(ecc, ramoops_ecc, int, 0400);
70MODULE_PARM_DESC(ramoops_ecc,
71 "if non-zero, the option enables ECC support and specifies "
72 "ECC buffer size in bytes (1 is a special value, means 16 "
73 "bytes ECC)");
74
75static int ramoops_dump_oops = -1;
76module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
77MODULE_PARM_DESC(dump_oops,
78 "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
79
80struct ramoops_context {
81 struct persistent_ram_zone **dprzs; /* Oops dump zones */
82 struct persistent_ram_zone *cprz; /* Console zone */
83 struct persistent_ram_zone **fprzs; /* Ftrace zones */
84 struct persistent_ram_zone *mprz; /* PMSG zone */
85 phys_addr_t phys_addr;
86 unsigned long size;
87 unsigned int memtype;
88 size_t record_size;
89 size_t console_size;
90 size_t ftrace_size;
91 size_t pmsg_size;
92 u32 flags;
93 struct persistent_ram_ecc_info ecc_info;
94 unsigned int max_dump_cnt;
95 unsigned int dump_write_cnt;
96 /* _read_cnt need clear on ramoops_pstore_open */
97 unsigned int dump_read_cnt;
98 unsigned int console_read_cnt;
99 unsigned int max_ftrace_cnt;
100 unsigned int ftrace_read_cnt;
101 unsigned int pmsg_read_cnt;
102 struct pstore_info pstore;
103};
104
105static struct platform_device *dummy;
106
107static int ramoops_pstore_open(struct pstore_info *psi)
108{
109 struct ramoops_context *cxt = psi->data;
110
111 cxt->dump_read_cnt = 0;
112 cxt->console_read_cnt = 0;
113 cxt->ftrace_read_cnt = 0;
114 cxt->pmsg_read_cnt = 0;
115 return 0;
116}
117
118static struct persistent_ram_zone *
119ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
120 struct pstore_record *record)
121{
122 struct persistent_ram_zone *prz;
123
124 /* Give up if we never existed or have hit the end. */
125 if (!przs)
126 return NULL;
127
128 prz = przs[id];
129 if (!prz)
130 return NULL;
131
132 /* Update old/shadowed buffer. */
133 if (prz->type == PSTORE_TYPE_DMESG)
134 persistent_ram_save_old(prz);
135
136 if (!persistent_ram_old_size(prz))
137 return NULL;
138
139 record->type = prz->type;
140 record->id = id;
141
142 return prz;
143}
144
145static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
146 bool *compressed)
147{
148 char data_type;
149 int header_length = 0;
150
151 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
152 (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
153 &header_length) == 3) {
154 time->tv_nsec *= 1000;
155 if (data_type == 'C')
156 *compressed = true;
157 else
158 *compressed = false;
159 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
160 (time64_t *)&time->tv_sec, &time->tv_nsec,
161 &header_length) == 2) {
162 time->tv_nsec *= 1000;
163 *compressed = false;
164 } else {
165 time->tv_sec = 0;
166 time->tv_nsec = 0;
167 *compressed = false;
168 }
169 return header_length;
170}
171
172static bool prz_ok(struct persistent_ram_zone *prz)
173{
174 return !!prz && !!(persistent_ram_old_size(prz) +
175 persistent_ram_ecc_string(prz, NULL, len: 0));
176}
177
178static ssize_t ramoops_pstore_read(struct pstore_record *record)
179{
180 ssize_t size = 0;
181 struct ramoops_context *cxt = record->psi->data;
182 struct persistent_ram_zone *prz = NULL;
183 int header_length = 0;
184 bool free_prz = false;
185
186 /*
187 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
188 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
189 * valid time stamps, so it is initialized to zero.
190 */
191 record->time.tv_sec = 0;
192 record->time.tv_nsec = 0;
193 record->compressed = false;
194
195 /* Find the next valid persistent_ram_zone for DMESG */
196 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
197 prz = ramoops_get_next_prz(przs: cxt->dprzs, id: cxt->dump_read_cnt++,
198 record);
199 if (!prz_ok(prz))
200 continue;
201 header_length = ramoops_read_kmsg_hdr(buffer: persistent_ram_old(prz),
202 time: &record->time,
203 compressed: &record->compressed);
204 /* Clear and skip this DMESG record if it has no valid header */
205 if (!header_length) {
206 persistent_ram_free_old(prz);
207 persistent_ram_zap(prz);
208 prz = NULL;
209 }
210 }
211
212 if (!prz_ok(prz) && !cxt->console_read_cnt++)
213 prz = ramoops_get_next_prz(przs: &cxt->cprz, id: 0 /* single */, record);
214
215 if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
216 prz = ramoops_get_next_prz(przs: &cxt->mprz, id: 0 /* single */, record);
217
218 /* ftrace is last since it may want to dynamically allocate memory. */
219 if (!prz_ok(prz)) {
220 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
221 !cxt->ftrace_read_cnt++) {
222 prz = ramoops_get_next_prz(przs: cxt->fprzs, id: 0 /* single */,
223 record);
224 } else {
225 /*
226 * Build a new dummy record which combines all the
227 * per-cpu records including metadata and ecc info.
228 */
229 struct persistent_ram_zone *tmp_prz, *prz_next;
230
231 tmp_prz = kzalloc(size: sizeof(struct persistent_ram_zone),
232 GFP_KERNEL);
233 if (!tmp_prz)
234 return -ENOMEM;
235 prz = tmp_prz;
236 free_prz = true;
237
238 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
239 prz_next = ramoops_get_next_prz(przs: cxt->fprzs,
240 id: cxt->ftrace_read_cnt++, record);
241
242 if (!prz_ok(prz: prz_next))
243 continue;
244
245 tmp_prz->ecc_info = prz_next->ecc_info;
246 tmp_prz->corrected_bytes +=
247 prz_next->corrected_bytes;
248 tmp_prz->bad_blocks += prz_next->bad_blocks;
249
250 size = pstore_ftrace_combine_log(
251 dest_log: &tmp_prz->old_log,
252 dest_log_size: &tmp_prz->old_log_size,
253 src_log: prz_next->old_log,
254 src_log_size: prz_next->old_log_size);
255 if (size)
256 goto out;
257 }
258 record->id = 0;
259 }
260 }
261
262 if (!prz_ok(prz)) {
263 size = 0;
264 goto out;
265 }
266
267 size = persistent_ram_old_size(prz) - header_length;
268
269 /* ECC correction notice */
270 record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, len: 0);
271
272 record->buf = kvzalloc(size: size + record->ecc_notice_size + 1, GFP_KERNEL);
273 if (record->buf == NULL) {
274 size = -ENOMEM;
275 goto out;
276 }
277
278 memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
279 size);
280
281 persistent_ram_ecc_string(prz, str: record->buf + size,
282 len: record->ecc_notice_size + 1);
283
284out:
285 if (free_prz) {
286 kvfree(addr: prz->old_log);
287 kfree(objp: prz);
288 }
289
290 return size;
291}
292
293static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
294 struct pstore_record *record)
295{
296 char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
297 size_t len;
298
299 len = scnprintf(buf: hdr, size: sizeof(hdr),
300 RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
301 (time64_t)record->time.tv_sec,
302 record->time.tv_nsec / 1000,
303 record->compressed ? 'C' : 'D');
304 persistent_ram_write(prz, s: hdr, count: len);
305
306 return len;
307}
308
309static int notrace ramoops_pstore_write(struct pstore_record *record)
310{
311 struct ramoops_context *cxt = record->psi->data;
312 struct persistent_ram_zone *prz;
313 size_t size, hlen;
314
315 if (record->type == PSTORE_TYPE_CONSOLE) {
316 if (!cxt->cprz)
317 return -ENOMEM;
318 persistent_ram_write(prz: cxt->cprz, s: record->buf, count: record->size);
319 return 0;
320 } else if (record->type == PSTORE_TYPE_FTRACE) {
321 int zonenum;
322
323 if (!cxt->fprzs)
324 return -ENOMEM;
325 /*
326 * Choose zone by if we're using per-cpu buffers.
327 */
328 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
329 zonenum = smp_processor_id();
330 else
331 zonenum = 0;
332
333 persistent_ram_write(prz: cxt->fprzs[zonenum], s: record->buf,
334 count: record->size);
335 return 0;
336 } else if (record->type == PSTORE_TYPE_PMSG) {
337 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
338 return -EINVAL;
339 }
340
341 if (record->type != PSTORE_TYPE_DMESG)
342 return -EINVAL;
343
344 /*
345 * We could filter on record->reason here if we wanted to (which
346 * would duplicate what happened before the "max_reason" setting
347 * was added), but that would defeat the purpose of a system
348 * changing printk.always_kmsg_dump, so instead log everything that
349 * the kmsg dumper sends us, since it should be doing the filtering
350 * based on the combination of printk.always_kmsg_dump and our
351 * requested "max_reason".
352 */
353
354 /*
355 * Explicitly only take the first part of any new crash.
356 * If our buffer is larger than kmsg_bytes, this can never happen,
357 * and if our buffer is smaller than kmsg_bytes, we don't want the
358 * report split across multiple records.
359 */
360 if (record->part != 1)
361 return -ENOSPC;
362
363 if (!cxt->dprzs)
364 return -ENOSPC;
365
366 prz = cxt->dprzs[cxt->dump_write_cnt];
367
368 /*
369 * Since this is a new crash dump, we need to reset the buffer in
370 * case it still has an old dump present. Without this, the new dump
371 * will get appended, which would seriously confuse anything trying
372 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
373 * expects to find a dump header in the beginning of buffer data, so
374 * we must to reset the buffer values, in order to ensure that the
375 * header will be written to the beginning of the buffer.
376 */
377 persistent_ram_zap(prz);
378
379 /* Build header and append record contents. */
380 hlen = ramoops_write_kmsg_hdr(prz, record);
381 if (!hlen)
382 return -ENOMEM;
383
384 size = record->size;
385 if (size + hlen > prz->buffer_size)
386 size = prz->buffer_size - hlen;
387 persistent_ram_write(prz, s: record->buf, count: size);
388
389 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
390
391 return 0;
392}
393
394static int notrace ramoops_pstore_write_user(struct pstore_record *record,
395 const char __user *buf)
396{
397 if (record->type == PSTORE_TYPE_PMSG) {
398 struct ramoops_context *cxt = record->psi->data;
399
400 if (!cxt->mprz)
401 return -ENOMEM;
402 return persistent_ram_write_user(prz: cxt->mprz, s: buf, count: record->size);
403 }
404
405 return -EINVAL;
406}
407
408static int ramoops_pstore_erase(struct pstore_record *record)
409{
410 struct ramoops_context *cxt = record->psi->data;
411 struct persistent_ram_zone *prz;
412
413 switch (record->type) {
414 case PSTORE_TYPE_DMESG:
415 if (record->id >= cxt->max_dump_cnt)
416 return -EINVAL;
417 prz = cxt->dprzs[record->id];
418 break;
419 case PSTORE_TYPE_CONSOLE:
420 prz = cxt->cprz;
421 break;
422 case PSTORE_TYPE_FTRACE:
423 if (record->id >= cxt->max_ftrace_cnt)
424 return -EINVAL;
425 prz = cxt->fprzs[record->id];
426 break;
427 case PSTORE_TYPE_PMSG:
428 prz = cxt->mprz;
429 break;
430 default:
431 return -EINVAL;
432 }
433
434 persistent_ram_free_old(prz);
435 persistent_ram_zap(prz);
436
437 return 0;
438}
439
440static struct ramoops_context oops_cxt = {
441 .pstore = {
442 .owner = THIS_MODULE,
443 .name = "ramoops",
444 .open = ramoops_pstore_open,
445 .read = ramoops_pstore_read,
446 .write = ramoops_pstore_write,
447 .write_user = ramoops_pstore_write_user,
448 .erase = ramoops_pstore_erase,
449 },
450};
451
452static void ramoops_free_przs(struct ramoops_context *cxt)
453{
454 int i;
455
456 /* Free pmsg PRZ */
457 persistent_ram_free(prz: &cxt->mprz);
458
459 /* Free console PRZ */
460 persistent_ram_free(prz: &cxt->cprz);
461
462 /* Free dump PRZs */
463 if (cxt->dprzs) {
464 for (i = 0; i < cxt->max_dump_cnt; i++)
465 persistent_ram_free(prz: &cxt->dprzs[i]);
466
467 kfree(objp: cxt->dprzs);
468 cxt->dprzs = NULL;
469 cxt->max_dump_cnt = 0;
470 }
471
472 /* Free ftrace PRZs */
473 if (cxt->fprzs) {
474 for (i = 0; i < cxt->max_ftrace_cnt; i++)
475 persistent_ram_free(prz: &cxt->fprzs[i]);
476 kfree(objp: cxt->fprzs);
477 cxt->fprzs = NULL;
478 cxt->max_ftrace_cnt = 0;
479 }
480}
481
482static int ramoops_init_przs(const char *name,
483 struct device *dev, struct ramoops_context *cxt,
484 struct persistent_ram_zone ***przs,
485 phys_addr_t *paddr, size_t mem_sz,
486 ssize_t record_size,
487 unsigned int *cnt, u32 sig, u32 flags)
488{
489 int err = -ENOMEM;
490 int i;
491 size_t zone_sz;
492 struct persistent_ram_zone **prz_ar;
493
494 /* Allocate nothing for 0 mem_sz or 0 record_size. */
495 if (mem_sz == 0 || record_size == 0) {
496 *cnt = 0;
497 return 0;
498 }
499
500 /*
501 * If we have a negative record size, calculate it based on
502 * mem_sz / *cnt. If we have a positive record size, calculate
503 * cnt from mem_sz / record_size.
504 */
505 if (record_size < 0) {
506 if (*cnt == 0)
507 return 0;
508 record_size = mem_sz / *cnt;
509 if (record_size == 0) {
510 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
511 name, mem_sz, *cnt);
512 goto fail;
513 }
514 } else {
515 *cnt = mem_sz / record_size;
516 if (*cnt == 0) {
517 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
518 name, mem_sz, record_size);
519 goto fail;
520 }
521 }
522
523 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
524 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
525 name,
526 mem_sz, (unsigned long long)*paddr,
527 cxt->size, (unsigned long long)cxt->phys_addr);
528 goto fail;
529 }
530
531 zone_sz = mem_sz / *cnt;
532 if (!zone_sz) {
533 dev_err(dev, "%s zone size == 0\n", name);
534 goto fail;
535 }
536
537 prz_ar = kcalloc(n: *cnt, size: sizeof(**przs), GFP_KERNEL);
538 if (!prz_ar)
539 goto fail;
540
541 for (i = 0; i < *cnt; i++) {
542 char *label;
543
544 if (*cnt == 1)
545 label = kasprintf(GFP_KERNEL, fmt: "ramoops:%s", name);
546 else
547 label = kasprintf(GFP_KERNEL, fmt: "ramoops:%s(%d/%d)",
548 name, i, *cnt - 1);
549 prz_ar[i] = persistent_ram_new(start: *paddr, size: zone_sz, sig,
550 ecc_info: &cxt->ecc_info,
551 memtype: cxt->memtype, flags, label);
552 kfree(objp: label);
553 if (IS_ERR(ptr: prz_ar[i])) {
554 err = PTR_ERR(ptr: prz_ar[i]);
555 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
556 name, record_size,
557 (unsigned long long)*paddr, err);
558
559 while (i > 0) {
560 i--;
561 persistent_ram_free(prz: &prz_ar[i]);
562 }
563 kfree(objp: prz_ar);
564 prz_ar = NULL;
565 goto fail;
566 }
567 *paddr += zone_sz;
568 prz_ar[i]->type = pstore_name_to_type(name);
569 }
570
571 *przs = prz_ar;
572 return 0;
573
574fail:
575 *cnt = 0;
576 return err;
577}
578
579static int ramoops_init_prz(const char *name,
580 struct device *dev, struct ramoops_context *cxt,
581 struct persistent_ram_zone **prz,
582 phys_addr_t *paddr, size_t sz, u32 sig)
583{
584 char *label;
585
586 if (!sz)
587 return 0;
588
589 if (*paddr + sz - cxt->phys_addr > cxt->size) {
590 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
591 name, sz, (unsigned long long)*paddr,
592 cxt->size, (unsigned long long)cxt->phys_addr);
593 return -ENOMEM;
594 }
595
596 label = kasprintf(GFP_KERNEL, fmt: "ramoops:%s", name);
597 *prz = persistent_ram_new(start: *paddr, size: sz, sig, ecc_info: &cxt->ecc_info,
598 memtype: cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
599 kfree(objp: label);
600 if (IS_ERR(ptr: *prz)) {
601 int err = PTR_ERR(ptr: *prz);
602
603 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
604 name, sz, (unsigned long long)*paddr, err);
605 return err;
606 }
607
608 *paddr += sz;
609 (*prz)->type = pstore_name_to_type(name);
610
611 return 0;
612}
613
614/* Read a u32 from a dt property and make sure it's safe for an int. */
615static int ramoops_parse_dt_u32(struct platform_device *pdev,
616 const char *propname,
617 u32 default_value, u32 *value)
618{
619 u32 val32 = 0;
620 int ret;
621
622 ret = of_property_read_u32(np: pdev->dev.of_node, propname, out_value: &val32);
623 if (ret == -EINVAL) {
624 /* field is missing, use default value. */
625 val32 = default_value;
626 } else if (ret < 0) {
627 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
628 propname, ret);
629 return ret;
630 }
631
632 /* Sanity check our results. */
633 if (val32 > INT_MAX) {
634 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
635 return -EOVERFLOW;
636 }
637
638 *value = val32;
639 return 0;
640}
641
642static int ramoops_parse_dt(struct platform_device *pdev,
643 struct ramoops_platform_data *pdata)
644{
645 struct device_node *of_node = pdev->dev.of_node;
646 struct device_node *parent_node;
647 struct resource *res;
648 u32 value;
649 int ret;
650
651 dev_dbg(&pdev->dev, "using Device Tree\n");
652
653 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
654 if (!res) {
655 dev_err(&pdev->dev,
656 "failed to locate DT /reserved-memory resource\n");
657 return -EINVAL;
658 }
659
660 pdata->mem_size = resource_size(res);
661 pdata->mem_address = res->start;
662 /*
663 * Setting "unbuffered" is deprecated and will be ignored if
664 * "mem_type" is also specified.
665 */
666 pdata->mem_type = of_property_read_bool(np: of_node, propname: "unbuffered");
667 /*
668 * Setting "no-dump-oops" is deprecated and will be ignored if
669 * "max_reason" is also specified.
670 */
671 if (of_property_read_bool(np: of_node, propname: "no-dump-oops"))
672 pdata->max_reason = KMSG_DUMP_PANIC;
673 else
674 pdata->max_reason = KMSG_DUMP_OOPS;
675
676#define parse_u32(name, field, default_value) { \
677 ret = ramoops_parse_dt_u32(pdev, name, default_value, \
678 &value); \
679 if (ret < 0) \
680 return ret; \
681 field = value; \
682 }
683
684 parse_u32("mem-type", pdata->mem_type, pdata->mem_type);
685 parse_u32("record-size", pdata->record_size, 0);
686 parse_u32("console-size", pdata->console_size, 0);
687 parse_u32("ftrace-size", pdata->ftrace_size, 0);
688 parse_u32("pmsg-size", pdata->pmsg_size, 0);
689 parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);
690 parse_u32("flags", pdata->flags, 0);
691 parse_u32("max-reason", pdata->max_reason, pdata->max_reason);
692
693#undef parse_u32
694
695 /*
696 * Some old Chromebooks relied on the kernel setting the
697 * console_size and pmsg_size to the record size since that's
698 * what the downstream kernel did. These same Chromebooks had
699 * "ramoops" straight under the root node which isn't
700 * according to the current upstream bindings (though it was
701 * arguably acceptable under a prior version of the bindings).
702 * Let's make those old Chromebooks work by detecting that
703 * we're not a child of "reserved-memory" and mimicking the
704 * expected behavior.
705 */
706 parent_node = of_get_parent(node: of_node);
707 if (!of_node_name_eq(np: parent_node, name: "reserved-memory") &&
708 !pdata->console_size && !pdata->ftrace_size &&
709 !pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
710 pdata->console_size = pdata->record_size;
711 pdata->pmsg_size = pdata->record_size;
712 }
713 of_node_put(node: parent_node);
714
715 return 0;
716}
717
718static int ramoops_probe(struct platform_device *pdev)
719{
720 struct device *dev = &pdev->dev;
721 struct ramoops_platform_data *pdata = dev->platform_data;
722 struct ramoops_platform_data pdata_local;
723 struct ramoops_context *cxt = &oops_cxt;
724 size_t dump_mem_sz;
725 phys_addr_t paddr;
726 int err = -EINVAL;
727
728 /*
729 * Only a single ramoops area allowed at a time, so fail extra
730 * probes.
731 */
732 if (cxt->max_dump_cnt) {
733 pr_err("already initialized\n");
734 goto fail_out;
735 }
736
737 if (dev_of_node(dev) && !pdata) {
738 pdata = &pdata_local;
739 memset(pdata, 0, sizeof(*pdata));
740
741 err = ramoops_parse_dt(pdev, pdata);
742 if (err < 0)
743 goto fail_out;
744 }
745
746 /* Make sure we didn't get bogus platform data pointer. */
747 if (!pdata) {
748 pr_err("NULL platform data\n");
749 err = -EINVAL;
750 goto fail_out;
751 }
752
753 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
754 !pdata->ftrace_size && !pdata->pmsg_size)) {
755 pr_err("The memory size and the record/console size must be "
756 "non-zero\n");
757 err = -EINVAL;
758 goto fail_out;
759 }
760
761 if (pdata->record_size && !is_power_of_2(n: pdata->record_size))
762 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
763 if (pdata->console_size && !is_power_of_2(n: pdata->console_size))
764 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
765 if (pdata->ftrace_size && !is_power_of_2(n: pdata->ftrace_size))
766 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
767 if (pdata->pmsg_size && !is_power_of_2(n: pdata->pmsg_size))
768 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
769
770 cxt->size = pdata->mem_size;
771 cxt->phys_addr = pdata->mem_address;
772 cxt->memtype = pdata->mem_type;
773 cxt->record_size = pdata->record_size;
774 cxt->console_size = pdata->console_size;
775 cxt->ftrace_size = pdata->ftrace_size;
776 cxt->pmsg_size = pdata->pmsg_size;
777 cxt->flags = pdata->flags;
778 cxt->ecc_info = pdata->ecc_info;
779
780 paddr = cxt->phys_addr;
781
782 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
783 - cxt->pmsg_size;
784 err = ramoops_init_przs(name: "dmesg", dev, cxt, przs: &cxt->dprzs, paddr: &paddr,
785 mem_sz: dump_mem_sz, record_size: cxt->record_size,
786 cnt: &cxt->max_dump_cnt, sig: 0, flags: 0);
787 if (err)
788 goto fail_init;
789
790 err = ramoops_init_prz(name: "console", dev, cxt, prz: &cxt->cprz, paddr: &paddr,
791 sz: cxt->console_size, sig: 0);
792 if (err)
793 goto fail_init;
794
795 err = ramoops_init_prz(name: "pmsg", dev, cxt, prz: &cxt->mprz, paddr: &paddr,
796 sz: cxt->pmsg_size, sig: 0);
797 if (err)
798 goto fail_init;
799
800 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
801 ? nr_cpu_ids
802 : 1;
803 err = ramoops_init_przs(name: "ftrace", dev, cxt, przs: &cxt->fprzs, paddr: &paddr,
804 mem_sz: cxt->ftrace_size, record_size: -1,
805 cnt: &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
806 flags: (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
807 ? PRZ_FLAG_NO_LOCK : 0);
808 if (err)
809 goto fail_init;
810
811 cxt->pstore.data = cxt;
812 /*
813 * Prepare frontend flags based on which areas are initialized.
814 * For ramoops_init_przs() cases, the "max count" variable tells
815 * if there are regions present. For ramoops_init_prz() cases,
816 * the single region size is how to check.
817 */
818 cxt->pstore.flags = 0;
819 if (cxt->max_dump_cnt) {
820 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
821 cxt->pstore.max_reason = pdata->max_reason;
822 }
823 if (cxt->console_size)
824 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
825 if (cxt->max_ftrace_cnt)
826 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
827 if (cxt->pmsg_size)
828 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
829
830 /*
831 * Since bufsize is only used for dmesg crash dumps, it
832 * must match the size of the dprz record (after PRZ header
833 * and ECC bytes have been accounted for).
834 */
835 if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
836 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
837 cxt->pstore.buf = kvzalloc(size: cxt->pstore.bufsize, GFP_KERNEL);
838 if (!cxt->pstore.buf) {
839 pr_err("cannot allocate pstore crash dump buffer\n");
840 err = -ENOMEM;
841 goto fail_clear;
842 }
843 }
844
845 err = pstore_register(&cxt->pstore);
846 if (err) {
847 pr_err("registering with pstore failed\n");
848 goto fail_buf;
849 }
850
851 /*
852 * Update the module parameter variables as well so they are visible
853 * through /sys/module/ramoops/parameters/
854 */
855 mem_size = pdata->mem_size;
856 mem_address = pdata->mem_address;
857 record_size = pdata->record_size;
858 ramoops_max_reason = pdata->max_reason;
859 ramoops_console_size = pdata->console_size;
860 ramoops_pmsg_size = pdata->pmsg_size;
861 ramoops_ftrace_size = pdata->ftrace_size;
862
863 pr_info("using 0x%lx@0x%llx, ecc: %d\n",
864 cxt->size, (unsigned long long)cxt->phys_addr,
865 cxt->ecc_info.ecc_size);
866
867 return 0;
868
869fail_buf:
870 kvfree(addr: cxt->pstore.buf);
871fail_clear:
872 cxt->pstore.bufsize = 0;
873fail_init:
874 ramoops_free_przs(cxt);
875fail_out:
876 return err;
877}
878
879static void ramoops_remove(struct platform_device *pdev)
880{
881 struct ramoops_context *cxt = &oops_cxt;
882
883 pstore_unregister(&cxt->pstore);
884
885 kvfree(addr: cxt->pstore.buf);
886 cxt->pstore.bufsize = 0;
887
888 ramoops_free_przs(cxt);
889}
890
891static const struct of_device_id dt_match[] = {
892 { .compatible = "ramoops" },
893 {}
894};
895
896static struct platform_driver ramoops_driver = {
897 .probe = ramoops_probe,
898 .remove_new = ramoops_remove,
899 .driver = {
900 .name = "ramoops",
901 .of_match_table = dt_match,
902 },
903};
904
905static inline void ramoops_unregister_dummy(void)
906{
907 platform_device_unregister(dummy);
908 dummy = NULL;
909}
910
911static void __init ramoops_register_dummy(void)
912{
913 struct ramoops_platform_data pdata;
914
915 /*
916 * Prepare a dummy platform data structure to carry the module
917 * parameters. If mem_size isn't set, then there are no module
918 * parameters, and we can skip this.
919 */
920 if (!mem_size)
921 return;
922
923 pr_info("using module parameters\n");
924
925 memset(&pdata, 0, sizeof(pdata));
926 pdata.mem_size = mem_size;
927 pdata.mem_address = mem_address;
928 pdata.mem_type = mem_type;
929 pdata.record_size = record_size;
930 pdata.console_size = ramoops_console_size;
931 pdata.ftrace_size = ramoops_ftrace_size;
932 pdata.pmsg_size = ramoops_pmsg_size;
933 /* If "max_reason" is set, its value has priority over "dump_oops". */
934 if (ramoops_max_reason >= 0)
935 pdata.max_reason = ramoops_max_reason;
936 /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
937 else if (ramoops_dump_oops != -1)
938 pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
939 : KMSG_DUMP_PANIC;
940 /* And if neither are explicitly set, use the default. */
941 else
942 pdata.max_reason = KMSG_DUMP_OOPS;
943 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
944
945 /*
946 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
947 * (using 1 byte for ECC isn't much of use anyway).
948 */
949 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
950
951 dummy = platform_device_register_data(NULL, name: "ramoops", id: -1,
952 data: &pdata, size: sizeof(pdata));
953 if (IS_ERR(ptr: dummy)) {
954 pr_info("could not create platform device: %ld\n",
955 PTR_ERR(dummy));
956 dummy = NULL;
957 }
958}
959
960static int __init ramoops_init(void)
961{
962 int ret;
963
964 ramoops_register_dummy();
965 ret = platform_driver_register(&ramoops_driver);
966 if (ret != 0)
967 ramoops_unregister_dummy();
968
969 return ret;
970}
971postcore_initcall(ramoops_init);
972
973static void __exit ramoops_exit(void)
974{
975 platform_driver_unregister(&ramoops_driver);
976 ramoops_unregister_dummy();
977}
978module_exit(ramoops_exit);
979
980MODULE_LICENSE("GPL");
981MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
982MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
983

source code of linux/fs/pstore/ram.c