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