fs/pstore/ram.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * RAM Oops/Panic logger
   4  *
   5  * Copyright (C) 2010 Marco Stornelli <[email protected]>
   6  * Copyright (C) 2011 Kees Cook <[email protected]>
   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
  31 static ulong record_size = MIN_MEM_SIZE;
  32 module_param(record_size, ulong, 0400);
  33 MODULE_PARM_DESC(record_size,
  34                 "size of each dump done on oops/panic");
  35
  36 static ulong ramoops_console_size = MIN_MEM_SIZE;
  37 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  38 MODULE_PARM_DESC(console_size, "size of kernel console log");
  39
  40 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  41 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  42 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  43
  44 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  45 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  46 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  47
  48 static unsigned long long mem_address;
  49 module_param_hw(mem_address, ullong, other, 0400);
  50 MODULE_PARM_DESC(mem_address,
  51                 "start of reserved RAM used to store oops/panic logs");
  52
  53 static ulong mem_size;
  54 module_param(mem_size, ulong, 0400);
  55 MODULE_PARM_DESC(mem_size,
  56                 "size of reserved RAM used to store oops/panic logs");
  57
  58 static unsigned int mem_type;
  59 module_param(mem_type, uint, 0400);
  60 MODULE_PARM_DESC(mem_type,
  61                 "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
  62
  63 static int ramoops_max_reason = -1;
  64 module_param_named(max_reason, ramoops_max_reason, int, 0400);
  65 MODULE_PARM_DESC(max_reason,
  66                  "maximum reason for kmsg dump (default 2: Oops and Panic) ");
  67
  68 static int ramoops_ecc;
  69 module_param_named(ecc, ramoops_ecc, int, 0400);
  70 MODULE_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
  75 static int ramoops_dump_oops = -1;
  76 module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
  77 MODULE_PARM_DESC(dump_oops,
  78                  "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
  79
  80 struct 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
 105 static struct platform_device *dummy;
 106
 107 static 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
 118 static struct persistent_ram_zone *
 119 ramoops_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
 145 static 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
 172 static bool prz_ok(struct persistent_ram_zone *prz)
 173 {
 174         return !!prz && !!(persistent_ram_old_size(prz) +
 175                            persistent_ram_ecc_string(prz, NULL, 0));
 176 }
 177
 178 static 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(cxt->dprzs, cxt->dump_read_cnt++,
 198                                            record);
 199                 if (!prz_ok(prz))
 200                         continue;
 201                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 202                                                       &record->time,
 203                                                       &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(&cxt->cprz, 0 /* single */, record);
 214
 215         if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
 216                 prz = ramoops_get_next_prz(&cxt->mprz, 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(cxt->fprzs, 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(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(cxt->fprzs,
 240                                                 cxt->ftrace_read_cnt++, record);
 241
 242                                 if (!prz_ok(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                                                 &tmp_prz->old_log,
 252                                                 &tmp_prz->old_log_size,
 253                                                 prz_next->old_log,
 254                                                 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, 0);
 271
 272         record->buf = kvzalloc(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, record->buf + size,
 282                                   record->ecc_notice_size + 1);
 283
 284 out:
 285         if (free_prz) {
 286                 kvfree(prz->old_log);
 287                 kfree(prz);
 288         }
 289
 290         return size;
 291 }
 292
 293 static 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(hdr, 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, hdr, len);
 305
 306         return len;
 307 }
 308
 309 static 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(cxt->cprz, record->buf, 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(cxt->fprzs[zonenum], record->buf,
 334                                      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, record->buf, size);
 388
 389         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 390
 391         return 0;
 392 }
 393
 394 static 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(cxt->mprz, buf, record->size);
 403         }
 404
 405         return -EINVAL;
 406 }
 407
 408 static 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
 440 static 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
 452 static void ramoops_free_przs(struct ramoops_context *cxt)
 453 {
 454         int i;
 455
 456         /* Free pmsg PRZ */
 457         persistent_ram_free(&cxt->mprz);
 458
 459         /* Free console PRZ */
 460         persistent_ram_free(&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(&cxt->dprzs[i]);
 466
 467                 kfree(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(&cxt->fprzs[i]);
 476                 kfree(cxt->fprzs);
 477                 cxt->fprzs = NULL;
 478                 cxt->max_ftrace_cnt = 0;
 479         }
 480 }
 481
 482 static 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(*cnt, 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, "ramoops:%s", name);
 546                 else
 547                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
 548                                           name, i, *cnt - 1);
 549                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 550                                                &cxt->ecc_info,
 551                                                cxt->memtype, flags, label);
 552                 kfree(label);
 553                 if (IS_ERR(prz_ar[i])) {
 554                         err = PTR_ERR(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_ar[i]);
 562                         }
 563                         kfree(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
 574 fail:
 575         *cnt = 0;
 576         return err;
 577 }
 578
 579 static 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, "ramoops:%s", name);
 597         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 598                                   cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
 599         kfree(label);
 600         if (IS_ERR(*prz)) {
 601                 int err = PTR_ERR(*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. */
 615 static 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(pdev->dev.of_node, propname, &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
 642 static 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(of_node, "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(of_node, "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(of_node);
 707         if (!of_node_name_eq(parent_node, "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(parent_node);
 714
 715         return 0;
 716 }
 717
 718 static 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(pdata->record_size))
 762                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 763         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 764                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 765         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 766                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 767         if (pdata->pmsg_size && !is_power_of_2(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("dmesg", dev, cxt, &cxt->dprzs, &paddr,
 785                                 dump_mem_sz, cxt->record_size,
 786                                 &cxt->max_dump_cnt, 0, 0);
 787         if (err)
 788                 goto fail_init;
 789
 790         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 791                                cxt->console_size, 0);
 792         if (err)
 793                 goto fail_init;
 794
 795         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 796                                 cxt->pmsg_size, 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("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 804                                 cxt->ftrace_size, -1,
 805                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 806                                 (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(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
 869 fail_buf:
 870         kvfree(cxt->pstore.buf);
 871 fail_clear:
 872         cxt->pstore.bufsize = 0;
 873 fail_init:
 874         ramoops_free_przs(cxt);
 875 fail_out:
 876         return err;
 877 }
 878
 879 static void ramoops_remove(struct platform_device *pdev)
 880 {
 881         struct ramoops_context *cxt = &oops_cxt;
 882
 883         pstore_unregister(&cxt->pstore);
 884
 885         kvfree(cxt->pstore.buf);
 886         cxt->pstore.bufsize = 0;
 887
 888         ramoops_free_przs(cxt);
 889 }
 890
 891 static const struct of_device_id dt_match[] = {
 892         { .compatible = "ramoops" },
 893         {}
 894 };
 895
 896 static 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
 905 static inline void ramoops_unregister_dummy(void)
 906 {
 907         platform_device_unregister(dummy);
 908         dummy = NULL;
 909 }
 910
 911 static 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, "ramoops", -1,
 952                         &pdata, sizeof(pdata));
 953         if (IS_ERR(dummy)) {
 954                 pr_info("could not create platform device: %ld\n",
 955                         PTR_ERR(dummy));
 956                 dummy = NULL;
 957         }
 958 }
 959
 960 static 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 }
 971 postcore_initcall(ramoops_init);
 972
 973 static void __exit ramoops_exit(void)
 974 {
 975         platform_driver_unregister(&ramoops_driver);
 976         ramoops_unregister_dummy();
 977 }
 978 module_exit(ramoops_exit);
 979
 980 MODULE_LICENSE("GPL");
 981 MODULE_AUTHOR("Marco Stornelli <[email protected]>");
 982 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");