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/pstore_ram.h>
22 #include <linux/of.h>
23 #include <linux/of_address.h>
24
25 #define RAMOOPS_KERNMSG_HDR "===="
26 #define MIN_MEM_SIZE 4096UL
27
28 static ulong record_size = MIN_MEM_SIZE;
29 module_param(record_size, ulong, 0400);
30 MODULE_PARM_DESC(record_size,
31 "size of each dump done on oops/panic");
32
33 static ulong ramoops_console_size = MIN_MEM_SIZE;
34 module_param_named(console_size, ramoops_console_size, ulong, 0400);
35 MODULE_PARM_DESC(console_size, "size of kernel console log");
36
37 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
38 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
39 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
40
41 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
42 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
43 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
44
45 static unsigned long long mem_address;
46 module_param_hw(mem_address, ullong, other, 0400);
47 MODULE_PARM_DESC(mem_address,
48 "start of reserved RAM used to store oops/panic logs");
49
50 static ulong mem_size;
51 module_param(mem_size, ulong, 0400);
52 MODULE_PARM_DESC(mem_size,
53 "size of reserved RAM used to store oops/panic logs");
54
55 static unsigned int mem_type;
56 module_param(mem_type, uint, 0600);
57 MODULE_PARM_DESC(mem_type,
58 "set to 1 to try to use unbuffered memory (default 0)");
59
60 static int dump_oops = 1;
61 module_param(dump_oops, int, 0600);
62 MODULE_PARM_DESC(dump_oops,
63 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
64
65 static int ramoops_ecc;
66 module_param_named(ecc, ramoops_ecc, int, 0600);
67 MODULE_PARM_DESC(ramoops_ecc,
68 "if non-zero, the option enables ECC support and specifies "
69 "ECC buffer size in bytes (1 is a special value, means 16 "
70 "bytes ECC)");
71
72 struct ramoops_context {
73 struct persistent_ram_zone **dprzs; /* Oops dump zones */
74 struct persistent_ram_zone *cprz; /* Console zone */
75 struct persistent_ram_zone **fprzs; /* Ftrace zones */
76 struct persistent_ram_zone *mprz; /* PMSG zone */
77 phys_addr_t phys_addr;
78 unsigned long size;
79 unsigned int memtype;
80 size_t record_size;
81 size_t console_size;
82 size_t ftrace_size;
83 size_t pmsg_size;
84 int dump_oops;
85 u32 flags;
86 struct persistent_ram_ecc_info ecc_info;
87 unsigned int max_dump_cnt;
88 unsigned int dump_write_cnt;
89 /* _read_cnt need clear on ramoops_pstore_open */
90 unsigned int dump_read_cnt;
91 unsigned int console_read_cnt;
92 unsigned int max_ftrace_cnt;
93 unsigned int ftrace_read_cnt;
94 unsigned int pmsg_read_cnt;
95 struct pstore_info pstore;
96 };
97
98 static struct platform_device *dummy;
99
ramoops_pstore_open(struct pstore_info * psi)100 static int ramoops_pstore_open(struct pstore_info *psi)
101 {
102 struct ramoops_context *cxt = psi->data;
103
104 cxt->dump_read_cnt = 0;
105 cxt->console_read_cnt = 0;
106 cxt->ftrace_read_cnt = 0;
107 cxt->pmsg_read_cnt = 0;
108 return 0;
109 }
110
111 static struct persistent_ram_zone *
ramoops_get_next_prz(struct persistent_ram_zone * przs[],int id,struct pstore_record * record)112 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
113 struct pstore_record *record)
114 {
115 struct persistent_ram_zone *prz;
116
117 /* Give up if we never existed or have hit the end. */
118 if (!przs)
119 return NULL;
120
121 prz = przs[id];
122 if (!prz)
123 return NULL;
124
125 /* Update old/shadowed buffer. */
126 if (prz->type == PSTORE_TYPE_DMESG)
127 persistent_ram_save_old(prz);
128
129 if (!persistent_ram_old_size(prz))
130 return NULL;
131
132 record->type = prz->type;
133 record->id = id;
134
135 return prz;
136 }
137
ramoops_read_kmsg_hdr(char * buffer,struct timespec64 * time,bool * compressed)138 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
139 bool *compressed)
140 {
141 char data_type;
142 int header_length = 0;
143
144 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
145 (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
146 &header_length) == 3) {
147 time->tv_nsec *= 1000;
148 if (data_type == 'C')
149 *compressed = true;
150 else
151 *compressed = false;
152 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
153 (time64_t *)&time->tv_sec, &time->tv_nsec,
154 &header_length) == 2) {
155 time->tv_nsec *= 1000;
156 *compressed = false;
157 } else {
158 time->tv_sec = 0;
159 time->tv_nsec = 0;
160 *compressed = false;
161 }
162 return header_length;
163 }
164
prz_ok(struct persistent_ram_zone * prz)165 static bool prz_ok(struct persistent_ram_zone *prz)
166 {
167 return !!prz && !!(persistent_ram_old_size(prz) +
168 persistent_ram_ecc_string(prz, NULL, 0));
169 }
170
ftrace_log_combine(struct persistent_ram_zone * dest,struct persistent_ram_zone * src)171 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
172 struct persistent_ram_zone *src)
173 {
174 size_t dest_size, src_size, total, dest_off, src_off;
175 size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
176 void *merged_buf;
177 struct pstore_ftrace_record *drec, *srec, *mrec;
178 size_t record_size = sizeof(struct pstore_ftrace_record);
179
180 dest_off = dest->old_log_size % record_size;
181 dest_size = dest->old_log_size - dest_off;
182
183 src_off = src->old_log_size % record_size;
184 src_size = src->old_log_size - src_off;
185
186 total = dest_size + src_size;
187 merged_buf = kmalloc(total, GFP_KERNEL);
188 if (!merged_buf)
189 return -ENOMEM;
190
191 drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
192 srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
193 mrec = (struct pstore_ftrace_record *)(merged_buf);
194
195 while (dest_size > 0 && src_size > 0) {
196 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
197 pstore_ftrace_read_timestamp(&srec[src_idx])) {
198 mrec[merged_idx++] = drec[dest_idx++];
199 dest_size -= record_size;
200 } else {
201 mrec[merged_idx++] = srec[src_idx++];
202 src_size -= record_size;
203 }
204 }
205
206 while (dest_size > 0) {
207 mrec[merged_idx++] = drec[dest_idx++];
208 dest_size -= record_size;
209 }
210
211 while (src_size > 0) {
212 mrec[merged_idx++] = srec[src_idx++];
213 src_size -= record_size;
214 }
215
216 kfree(dest->old_log);
217 dest->old_log = merged_buf;
218 dest->old_log_size = total;
219
220 return 0;
221 }
222
ramoops_pstore_read(struct pstore_record * record)223 static ssize_t ramoops_pstore_read(struct pstore_record *record)
224 {
225 ssize_t size = 0;
226 struct ramoops_context *cxt = record->psi->data;
227 struct persistent_ram_zone *prz = NULL;
228 int header_length = 0;
229 bool free_prz = false;
230
231 /*
232 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
233 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
234 * valid time stamps, so it is initialized to zero.
235 */
236 record->time.tv_sec = 0;
237 record->time.tv_nsec = 0;
238 record->compressed = false;
239
240 /* Find the next valid persistent_ram_zone for DMESG */
241 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
242 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
243 record);
244 if (!prz_ok(prz))
245 continue;
246 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
247 &record->time,
248 &record->compressed);
249 /* Clear and skip this DMESG record if it has no valid header */
250 if (!header_length) {
251 persistent_ram_free_old(prz);
252 persistent_ram_zap(prz);
253 prz = NULL;
254 }
255 }
256
257 if (!prz_ok(prz) && !cxt->console_read_cnt++)
258 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
259
260 if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
261 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
262
263 /* ftrace is last since it may want to dynamically allocate memory. */
264 if (!prz_ok(prz)) {
265 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
266 !cxt->ftrace_read_cnt++) {
267 prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
268 record);
269 } else {
270 /*
271 * Build a new dummy record which combines all the
272 * per-cpu records including metadata and ecc info.
273 */
274 struct persistent_ram_zone *tmp_prz, *prz_next;
275
276 tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
277 GFP_KERNEL);
278 if (!tmp_prz)
279 return -ENOMEM;
280 prz = tmp_prz;
281 free_prz = true;
282
283 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
284 prz_next = ramoops_get_next_prz(cxt->fprzs,
285 cxt->ftrace_read_cnt++, record);
286
287 if (!prz_ok(prz_next))
288 continue;
289
290 tmp_prz->ecc_info = prz_next->ecc_info;
291 tmp_prz->corrected_bytes +=
292 prz_next->corrected_bytes;
293 tmp_prz->bad_blocks += prz_next->bad_blocks;
294 size = ftrace_log_combine(tmp_prz, prz_next);
295 if (size)
296 goto out;
297 }
298 record->id = 0;
299 }
300 }
301
302 if (!prz_ok(prz)) {
303 size = 0;
304 goto out;
305 }
306
307 size = persistent_ram_old_size(prz) - header_length;
308
309 /* ECC correction notice */
310 record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
311
312 record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
313 if (record->buf == NULL) {
314 size = -ENOMEM;
315 goto out;
316 }
317
318 memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
319 size);
320
321 persistent_ram_ecc_string(prz, record->buf + size,
322 record->ecc_notice_size + 1);
323
324 out:
325 if (free_prz) {
326 kfree(prz->old_log);
327 kfree(prz);
328 }
329
330 return size;
331 }
332
ramoops_write_kmsg_hdr(struct persistent_ram_zone * prz,struct pstore_record * record)333 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
334 struct pstore_record *record)
335 {
336 char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
337 size_t len;
338
339 len = scnprintf(hdr, sizeof(hdr),
340 RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
341 (time64_t)record->time.tv_sec,
342 record->time.tv_nsec / 1000,
343 record->compressed ? 'C' : 'D');
344 persistent_ram_write(prz, hdr, len);
345
346 return len;
347 }
348
ramoops_pstore_write(struct pstore_record * record)349 static int notrace ramoops_pstore_write(struct pstore_record *record)
350 {
351 struct ramoops_context *cxt = record->psi->data;
352 struct persistent_ram_zone *prz;
353 size_t size, hlen;
354
355 if (record->type == PSTORE_TYPE_CONSOLE) {
356 if (!cxt->cprz)
357 return -ENOMEM;
358 persistent_ram_write(cxt->cprz, record->buf, record->size);
359 return 0;
360 } else if (record->type == PSTORE_TYPE_FTRACE) {
361 int zonenum;
362
363 if (!cxt->fprzs)
364 return -ENOMEM;
365 /*
366 * Choose zone by if we're using per-cpu buffers.
367 */
368 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
369 zonenum = smp_processor_id();
370 else
371 zonenum = 0;
372
373 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
374 record->size);
375 return 0;
376 } else if (record->type == PSTORE_TYPE_PMSG) {
377 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
378 return -EINVAL;
379 }
380
381 if (record->type != PSTORE_TYPE_DMESG)
382 return -EINVAL;
383
384 /*
385 * Out of the various dmesg dump types, ramoops is currently designed
386 * to only store crash logs, rather than storing general kernel logs.
387 */
388 if (record->reason != KMSG_DUMP_OOPS &&
389 record->reason != KMSG_DUMP_PANIC)
390 return -EINVAL;
391
392 /* Skip Oopes when configured to do so. */
393 if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
394 return -EINVAL;
395
396 /*
397 * Explicitly only take the first part of any new crash.
398 * If our buffer is larger than kmsg_bytes, this can never happen,
399 * and if our buffer is smaller than kmsg_bytes, we don't want the
400 * report split across multiple records.
401 */
402 if (record->part != 1)
403 return -ENOSPC;
404
405 if (!cxt->dprzs)
406 return -ENOSPC;
407
408 prz = cxt->dprzs[cxt->dump_write_cnt];
409
410 /*
411 * Since this is a new crash dump, we need to reset the buffer in
412 * case it still has an old dump present. Without this, the new dump
413 * will get appended, which would seriously confuse anything trying
414 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
415 * expects to find a dump header in the beginning of buffer data, so
416 * we must to reset the buffer values, in order to ensure that the
417 * header will be written to the beginning of the buffer.
418 */
419 persistent_ram_zap(prz);
420
421 /* Build header and append record contents. */
422 hlen = ramoops_write_kmsg_hdr(prz, record);
423 if (!hlen)
424 return -ENOMEM;
425
426 size = record->size;
427 if (size + hlen > prz->buffer_size)
428 size = prz->buffer_size - hlen;
429 persistent_ram_write(prz, record->buf, size);
430
431 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
432
433 return 0;
434 }
435
ramoops_pstore_write_user(struct pstore_record * record,const char __user * buf)436 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
437 const char __user *buf)
438 {
439 if (record->type == PSTORE_TYPE_PMSG) {
440 struct ramoops_context *cxt = record->psi->data;
441
442 if (!cxt->mprz)
443 return -ENOMEM;
444 return persistent_ram_write_user(cxt->mprz, buf, record->size);
445 }
446
447 return -EINVAL;
448 }
449
ramoops_pstore_erase(struct pstore_record * record)450 static int ramoops_pstore_erase(struct pstore_record *record)
451 {
452 struct ramoops_context *cxt = record->psi->data;
453 struct persistent_ram_zone *prz;
454
455 switch (record->type) {
456 case PSTORE_TYPE_DMESG:
457 if (record->id >= cxt->max_dump_cnt)
458 return -EINVAL;
459 prz = cxt->dprzs[record->id];
460 break;
461 case PSTORE_TYPE_CONSOLE:
462 prz = cxt->cprz;
463 break;
464 case PSTORE_TYPE_FTRACE:
465 if (record->id >= cxt->max_ftrace_cnt)
466 return -EINVAL;
467 prz = cxt->fprzs[record->id];
468 break;
469 case PSTORE_TYPE_PMSG:
470 prz = cxt->mprz;
471 break;
472 default:
473 return -EINVAL;
474 }
475
476 persistent_ram_free_old(prz);
477 persistent_ram_zap(prz);
478
479 return 0;
480 }
481
482 static struct ramoops_context oops_cxt = {
483 .pstore = {
484 .owner = THIS_MODULE,
485 .name = "ramoops",
486 .open = ramoops_pstore_open,
487 .read = ramoops_pstore_read,
488 .write = ramoops_pstore_write,
489 .write_user = ramoops_pstore_write_user,
490 .erase = ramoops_pstore_erase,
491 },
492 };
493
ramoops_free_przs(struct ramoops_context * cxt)494 static void ramoops_free_przs(struct ramoops_context *cxt)
495 {
496 int i;
497
498 /* Free dump PRZs */
499 if (cxt->dprzs) {
500 for (i = 0; i < cxt->max_dump_cnt; i++)
501 persistent_ram_free(cxt->dprzs[i]);
502
503 kfree(cxt->dprzs);
504 cxt->max_dump_cnt = 0;
505 }
506
507 /* Free ftrace PRZs */
508 if (cxt->fprzs) {
509 for (i = 0; i < cxt->max_ftrace_cnt; i++)
510 persistent_ram_free(cxt->fprzs[i]);
511 kfree(cxt->fprzs);
512 cxt->max_ftrace_cnt = 0;
513 }
514 }
515
ramoops_init_przs(const char * name,struct device * dev,struct ramoops_context * cxt,struct persistent_ram_zone *** przs,phys_addr_t * paddr,size_t mem_sz,ssize_t record_size,unsigned int * cnt,u32 sig,u32 flags)516 static int ramoops_init_przs(const char *name,
517 struct device *dev, struct ramoops_context *cxt,
518 struct persistent_ram_zone ***przs,
519 phys_addr_t *paddr, size_t mem_sz,
520 ssize_t record_size,
521 unsigned int *cnt, u32 sig, u32 flags)
522 {
523 int err = -ENOMEM;
524 int i;
525 size_t zone_sz;
526 struct persistent_ram_zone **prz_ar;
527
528 /* Allocate nothing for 0 mem_sz or 0 record_size. */
529 if (mem_sz == 0 || record_size == 0) {
530 *cnt = 0;
531 return 0;
532 }
533
534 /*
535 * If we have a negative record size, calculate it based on
536 * mem_sz / *cnt. If we have a positive record size, calculate
537 * cnt from mem_sz / record_size.
538 */
539 if (record_size < 0) {
540 if (*cnt == 0)
541 return 0;
542 record_size = mem_sz / *cnt;
543 if (record_size == 0) {
544 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
545 name, mem_sz, *cnt);
546 goto fail;
547 }
548 } else {
549 *cnt = mem_sz / record_size;
550 if (*cnt == 0) {
551 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
552 name, mem_sz, record_size);
553 goto fail;
554 }
555 }
556
557 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
558 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
559 name,
560 mem_sz, (unsigned long long)*paddr,
561 cxt->size, (unsigned long long)cxt->phys_addr);
562 goto fail;
563 }
564
565 zone_sz = mem_sz / *cnt;
566 zone_sz = ALIGN_DOWN(zone_sz, 2);
567 if (!zone_sz) {
568 dev_err(dev, "%s zone size == 0\n", name);
569 goto fail;
570 }
571
572 prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
573 if (!prz_ar)
574 goto fail;
575
576 for (i = 0; i < *cnt; i++) {
577 char *label;
578
579 if (*cnt == 1)
580 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
581 else
582 label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
583 name, i, *cnt - 1);
584 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
585 &cxt->ecc_info,
586 cxt->memtype, flags, label);
587 kfree(label);
588 if (IS_ERR(prz_ar[i])) {
589 err = PTR_ERR(prz_ar[i]);
590 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
591 name, record_size,
592 (unsigned long long)*paddr, err);
593
594 while (i > 0) {
595 i--;
596 persistent_ram_free(prz_ar[i]);
597 }
598 kfree(prz_ar);
599 goto fail;
600 }
601 *paddr += zone_sz;
602 prz_ar[i]->type = pstore_name_to_type(name);
603 }
604
605 *przs = prz_ar;
606 return 0;
607
608 fail:
609 *cnt = 0;
610 return err;
611 }
612
ramoops_init_prz(const char * name,struct device * dev,struct ramoops_context * cxt,struct persistent_ram_zone ** prz,phys_addr_t * paddr,size_t sz,u32 sig)613 static int ramoops_init_prz(const char *name,
614 struct device *dev, struct ramoops_context *cxt,
615 struct persistent_ram_zone **prz,
616 phys_addr_t *paddr, size_t sz, u32 sig)
617 {
618 char *label;
619
620 if (!sz)
621 return 0;
622
623 if (*paddr + sz - cxt->phys_addr > cxt->size) {
624 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
625 name, sz, (unsigned long long)*paddr,
626 cxt->size, (unsigned long long)cxt->phys_addr);
627 return -ENOMEM;
628 }
629
630 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
631 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
632 cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
633 kfree(label);
634 if (IS_ERR(*prz)) {
635 int err = PTR_ERR(*prz);
636
637 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
638 name, sz, (unsigned long long)*paddr, err);
639 return err;
640 }
641
642 *paddr += sz;
643 (*prz)->type = pstore_name_to_type(name);
644
645 return 0;
646 }
647
ramoops_parse_dt_size(struct platform_device * pdev,const char * propname,u32 * value)648 static int ramoops_parse_dt_size(struct platform_device *pdev,
649 const char *propname, u32 *value)
650 {
651 u32 val32 = 0;
652 int ret;
653
654 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
655 if (ret < 0 && ret != -EINVAL) {
656 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
657 propname, ret);
658 return ret;
659 }
660
661 if (val32 > INT_MAX) {
662 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
663 return -EOVERFLOW;
664 }
665
666 *value = val32;
667 return 0;
668 }
669
ramoops_parse_dt(struct platform_device * pdev,struct ramoops_platform_data * pdata)670 static int ramoops_parse_dt(struct platform_device *pdev,
671 struct ramoops_platform_data *pdata)
672 {
673 struct device_node *of_node = pdev->dev.of_node;
674 struct device_node *parent_node;
675 struct resource *res;
676 u32 value;
677 int ret;
678
679 dev_dbg(&pdev->dev, "using Device Tree\n");
680
681 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
682 if (!res) {
683 dev_err(&pdev->dev,
684 "failed to locate DT /reserved-memory resource\n");
685 return -EINVAL;
686 }
687
688 pdata->mem_size = resource_size(res);
689 pdata->mem_address = res->start;
690 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
691 pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
692
693 #define parse_size(name, field) { \
694 ret = ramoops_parse_dt_size(pdev, name, &value); \
695 if (ret < 0) \
696 return ret; \
697 field = value; \
698 }
699
700 parse_size("record-size", pdata->record_size);
701 parse_size("console-size", pdata->console_size);
702 parse_size("ftrace-size", pdata->ftrace_size);
703 parse_size("pmsg-size", pdata->pmsg_size);
704 parse_size("ecc-size", pdata->ecc_info.ecc_size);
705 parse_size("flags", pdata->flags);
706
707 #undef parse_size
708
709 /*
710 * Some old Chromebooks relied on the kernel setting the
711 * console_size and pmsg_size to the record size since that's
712 * what the downstream kernel did. These same Chromebooks had
713 * "ramoops" straight under the root node which isn't
714 * according to the current upstream bindings (though it was
715 * arguably acceptable under a prior version of the bindings).
716 * Let's make those old Chromebooks work by detecting that
717 * we're not a child of "reserved-memory" and mimicking the
718 * expected behavior.
719 */
720 parent_node = of_get_parent(of_node);
721 if (!of_node_name_eq(parent_node, "reserved-memory") &&
722 !pdata->console_size && !pdata->ftrace_size &&
723 !pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
724 pdata->console_size = pdata->record_size;
725 pdata->pmsg_size = pdata->record_size;
726 }
727 of_node_put(parent_node);
728
729 return 0;
730 }
731
ramoops_probe(struct platform_device * pdev)732 static int ramoops_probe(struct platform_device *pdev)
733 {
734 struct device *dev = &pdev->dev;
735 struct ramoops_platform_data *pdata = dev->platform_data;
736 struct ramoops_platform_data pdata_local;
737 struct ramoops_context *cxt = &oops_cxt;
738 size_t dump_mem_sz;
739 phys_addr_t paddr;
740 int err = -EINVAL;
741
742 /*
743 * Only a single ramoops area allowed at a time, so fail extra
744 * probes.
745 */
746 if (cxt->max_dump_cnt) {
747 pr_err("already initialized\n");
748 goto fail_out;
749 }
750
751 if (dev_of_node(dev) && !pdata) {
752 pdata = &pdata_local;
753 memset(pdata, 0, sizeof(*pdata));
754
755 err = ramoops_parse_dt(pdev, pdata);
756 if (err < 0)
757 goto fail_out;
758 }
759
760 /* Make sure we didn't get bogus platform data pointer. */
761 if (!pdata) {
762 pr_err("NULL platform data\n");
763 err = -EINVAL;
764 goto fail_out;
765 }
766
767 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
768 !pdata->ftrace_size && !pdata->pmsg_size)) {
769 pr_err("The memory size and the record/console size must be "
770 "non-zero\n");
771 err = -EINVAL;
772 goto fail_out;
773 }
774
775 if (pdata->record_size && !is_power_of_2(pdata->record_size))
776 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
777 if (pdata->console_size && !is_power_of_2(pdata->console_size))
778 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
779 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
780 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
781 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
782 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
783
784 cxt->size = pdata->mem_size;
785 cxt->phys_addr = pdata->mem_address;
786 cxt->memtype = pdata->mem_type;
787 cxt->record_size = pdata->record_size;
788 cxt->console_size = pdata->console_size;
789 cxt->ftrace_size = pdata->ftrace_size;
790 cxt->pmsg_size = pdata->pmsg_size;
791 cxt->dump_oops = pdata->dump_oops;
792 cxt->flags = pdata->flags;
793 cxt->ecc_info = pdata->ecc_info;
794
795 paddr = cxt->phys_addr;
796
797 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
798 - cxt->pmsg_size;
799 err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
800 dump_mem_sz, cxt->record_size,
801 &cxt->max_dump_cnt, 0, 0);
802 if (err)
803 goto fail_out;
804
805 err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
806 cxt->console_size, 0);
807 if (err)
808 goto fail_init_cprz;
809
810 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
811 ? nr_cpu_ids
812 : 1;
813 err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
814 cxt->ftrace_size, -1,
815 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
816 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
817 ? PRZ_FLAG_NO_LOCK : 0);
818 if (err)
819 goto fail_init_fprz;
820
821 err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
822 cxt->pmsg_size, 0);
823 if (err)
824 goto fail_init_mprz;
825
826 cxt->pstore.data = cxt;
827 /*
828 * Prepare frontend flags based on which areas are initialized.
829 * For ramoops_init_przs() cases, the "max count" variable tells
830 * if there are regions present. For ramoops_init_prz() cases,
831 * the single region size is how to check.
832 */
833 cxt->pstore.flags = 0;
834 if (cxt->max_dump_cnt)
835 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
836 if (cxt->console_size)
837 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
838 if (cxt->max_ftrace_cnt)
839 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
840 if (cxt->pmsg_size)
841 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
842
843 /*
844 * Since bufsize is only used for dmesg crash dumps, it
845 * must match the size of the dprz record (after PRZ header
846 * and ECC bytes have been accounted for).
847 */
848 if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
849 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
850 cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
851 if (!cxt->pstore.buf) {
852 pr_err("cannot allocate pstore crash dump buffer\n");
853 err = -ENOMEM;
854 goto fail_clear;
855 }
856 }
857
858 err = pstore_register(&cxt->pstore);
859 if (err) {
860 pr_err("registering with pstore failed\n");
861 goto fail_buf;
862 }
863
864 /*
865 * Update the module parameter variables as well so they are visible
866 * through /sys/module/ramoops/parameters/
867 */
868 mem_size = pdata->mem_size;
869 mem_address = pdata->mem_address;
870 record_size = pdata->record_size;
871 dump_oops = pdata->dump_oops;
872 ramoops_console_size = pdata->console_size;
873 ramoops_pmsg_size = pdata->pmsg_size;
874 ramoops_ftrace_size = pdata->ftrace_size;
875
876 pr_info("using 0x%lx@0x%llx, ecc: %d\n",
877 cxt->size, (unsigned long long)cxt->phys_addr,
878 cxt->ecc_info.ecc_size);
879
880 return 0;
881
882 fail_buf:
883 kfree(cxt->pstore.buf);
884 fail_clear:
885 cxt->pstore.bufsize = 0;
886 persistent_ram_free(cxt->mprz);
887 fail_init_mprz:
888 fail_init_fprz:
889 persistent_ram_free(cxt->cprz);
890 fail_init_cprz:
891 ramoops_free_przs(cxt);
892 fail_out:
893 return err;
894 }
895
ramoops_remove(struct platform_device * pdev)896 static int ramoops_remove(struct platform_device *pdev)
897 {
898 struct ramoops_context *cxt = &oops_cxt;
899
900 pstore_unregister(&cxt->pstore);
901
902 kfree(cxt->pstore.buf);
903 cxt->pstore.bufsize = 0;
904
905 persistent_ram_free(cxt->mprz);
906 persistent_ram_free(cxt->cprz);
907 ramoops_free_przs(cxt);
908
909 return 0;
910 }
911
912 static const struct of_device_id dt_match[] = {
913 { .compatible = "ramoops" },
914 {}
915 };
916
917 static struct platform_driver ramoops_driver = {
918 .probe = ramoops_probe,
919 .remove = ramoops_remove,
920 .driver = {
921 .name = "ramoops",
922 .of_match_table = dt_match,
923 },
924 };
925
ramoops_unregister_dummy(void)926 static inline void ramoops_unregister_dummy(void)
927 {
928 platform_device_unregister(dummy);
929 dummy = NULL;
930 }
931
ramoops_register_dummy(void)932 static void __init ramoops_register_dummy(void)
933 {
934 struct ramoops_platform_data pdata;
935
936 /*
937 * Prepare a dummy platform data structure to carry the module
938 * parameters. If mem_size isn't set, then there are no module
939 * parameters, and we can skip this.
940 */
941 if (!mem_size)
942 return;
943
944 pr_info("using module parameters\n");
945
946 memset(&pdata, 0, sizeof(pdata));
947 pdata.mem_size = mem_size;
948 pdata.mem_address = mem_address;
949 pdata.mem_type = mem_type;
950 pdata.record_size = record_size;
951 pdata.console_size = ramoops_console_size;
952 pdata.ftrace_size = ramoops_ftrace_size;
953 pdata.pmsg_size = ramoops_pmsg_size;
954 pdata.dump_oops = dump_oops;
955 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
956
957 /*
958 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
959 * (using 1 byte for ECC isn't much of use anyway).
960 */
961 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
962
963 dummy = platform_device_register_data(NULL, "ramoops", -1,
964 &pdata, sizeof(pdata));
965 if (IS_ERR(dummy)) {
966 pr_info("could not create platform device: %ld\n",
967 PTR_ERR(dummy));
968 dummy = NULL;
969 ramoops_unregister_dummy();
970 }
971 }
972
ramoops_init(void)973 static int __init ramoops_init(void)
974 {
975 int ret;
976
977 ramoops_register_dummy();
978 ret = platform_driver_register(&ramoops_driver);
979 if (ret != 0)
980 ramoops_unregister_dummy();
981
982 return ret;
983 }
984 postcore_initcall(ramoops_init);
985
ramoops_exit(void)986 static void __exit ramoops_exit(void)
987 {
988 platform_driver_unregister(&ramoops_driver);
989 ramoops_unregister_dummy();
990 }
991 module_exit(ramoops_exit);
992
993 MODULE_LICENSE("GPL");
994 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
995 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
996