fs/pstore/ram.c

   1 /*
   2  * RAM Oops/Panic logger
   3  *
   4  * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
   5  * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/kernel.h>
  26 #include <linux/err.h>
  27 #include <linux/module.h>
  28 #include <linux/version.h>
  29 #include <linux/pstore.h>
  30 #include <linux/io.h>
  31 #include <linux/ioport.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/slab.h>
  34 #include <linux/compiler.h>
  35 #include <linux/pstore_ram.h>
  36 #include <linux/of.h>
  37 #include <linux/of_address.h>
  38
  39 #define RAMOOPS_KERNMSG_HDR "===="
  40 #define MIN_MEM_SIZE 4096UL
  41
  42 static ulong record_size = MIN_MEM_SIZE;
  43 module_param(record_size, ulong, 0400);
  44 MODULE_PARM_DESC(record_size,
  45                 "size of each dump done on oops/panic");
  46
  47 static ulong ramoops_console_size = MIN_MEM_SIZE;
  48 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  49 MODULE_PARM_DESC(console_size, "size of kernel console log");
  50
  51 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  52 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  53 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  54
  55 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  56 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  57 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  58
  59 static unsigned long long mem_address;
  60 module_param_hw(mem_address, ullong, other, 0400);
  61 MODULE_PARM_DESC(mem_address,
  62                 "start of reserved RAM used to store oops/panic logs");
  63
  64 static ulong mem_size;
  65 module_param(mem_size, ulong, 0400);
  66 MODULE_PARM_DESC(mem_size,
  67                 "size of reserved RAM used to store oops/panic logs");
  68
  69 static unsigned int mem_type;
  70 module_param(mem_type, uint, 0600);
  71 MODULE_PARM_DESC(mem_type,
  72                 "set to 1 to try to use unbuffered memory (default 0)");
  73
  74 static int dump_oops = 1;
  75 module_param(dump_oops, int, 0600);
  76 MODULE_PARM_DESC(dump_oops,
  77                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  78
  79 static int ramoops_ecc;
  80 module_param_named(ecc, ramoops_ecc, int, 0600);
  81 MODULE_PARM_DESC(ramoops_ecc,
  82                 "if non-zero, the option enables ECC support and specifies "
  83                 "ECC buffer size in bytes (1 is a special value, means 16 "
  84                 "bytes ECC)");
  85
  86 struct ramoops_context {
  87         struct persistent_ram_zone **dprzs;     /* Oops dump zones */
  88         struct persistent_ram_zone *cprz;       /* Console zone */
  89         struct persistent_ram_zone **fprzs;     /* Ftrace zones */
  90         struct persistent_ram_zone *mprz;       /* PMSG zone */
  91         phys_addr_t phys_addr;
  92         unsigned long size;
  93         unsigned int memtype;
  94         size_t record_size;
  95         size_t console_size;
  96         size_t ftrace_size;
  97         size_t pmsg_size;
  98         int dump_oops;
  99         u32 flags;
 100         struct persistent_ram_ecc_info ecc_info;
 101         unsigned int max_dump_cnt;
 102         unsigned int dump_write_cnt;
 103         /* _read_cnt need clear on ramoops_pstore_open */
 104         unsigned int dump_read_cnt;
 105         unsigned int console_read_cnt;
 106         unsigned int max_ftrace_cnt;
 107         unsigned int ftrace_read_cnt;
 108         unsigned int pmsg_read_cnt;
 109         struct pstore_info pstore;
 110 };
 111
 112 static struct platform_device *dummy;
 113 static struct ramoops_platform_data *dummy_data;
 114
 115 static int ramoops_pstore_open(struct pstore_info *psi)
 116 {
 117         struct ramoops_context *cxt = psi->data;
 118
 119         cxt->dump_read_cnt = 0;
 120         cxt->console_read_cnt = 0;
 121         cxt->ftrace_read_cnt = 0;
 122         cxt->pmsg_read_cnt = 0;
 123         return 0;
 124 }
 125
 126 static struct persistent_ram_zone *
 127 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
 128                      struct pstore_record *record)
 129 {
 130         struct persistent_ram_zone *prz;
 131
 132         /* Give up if we never existed or have hit the end. */
 133         if (!przs)
 134                 return NULL;
 135
 136         prz = przs[id];
 137         if (!prz)
 138                 return NULL;
 139
 140         /* Update old/shadowed buffer. */
 141         if (prz->type == PSTORE_TYPE_DMESG)
 142                 persistent_ram_save_old(prz);
 143
 144         if (!persistent_ram_old_size(prz))
 145                 return NULL;
 146
 147         record->type = prz->type;
 148         record->id = id;
 149
 150         return prz;
 151 }
 152
 153 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
 154                                   bool *compressed)
 155 {
 156         char data_type;
 157         int header_length = 0;
 158
 159         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
 160                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
 161                    &header_length) == 3) {
 162                 if (data_type == 'C')
 163                         *compressed = true;
 164                 else
 165                         *compressed = false;
 166         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 167                           (time64_t *)&time->tv_sec, &time->tv_nsec,
 168                           &header_length) == 2) {
 169                 *compressed = false;
 170         } else {
 171                 time->tv_sec = 0;
 172                 time->tv_nsec = 0;
 173                 *compressed = false;
 174         }
 175         return header_length;
 176 }
 177
 178 static bool prz_ok(struct persistent_ram_zone *prz)
 179 {
 180         return !!prz && !!(persistent_ram_old_size(prz) +
 181                            persistent_ram_ecc_string(prz, NULL, 0));
 182 }
 183
 184 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 185                                   struct persistent_ram_zone *src)
 186 {
 187         size_t dest_size, src_size, total, dest_off, src_off;
 188         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 189         void *merged_buf;
 190         struct pstore_ftrace_record *drec, *srec, *mrec;
 191         size_t record_size = sizeof(struct pstore_ftrace_record);
 192
 193         dest_off = dest->old_log_size % record_size;
 194         dest_size = dest->old_log_size - dest_off;
 195
 196         src_off = src->old_log_size % record_size;
 197         src_size = src->old_log_size - src_off;
 198
 199         total = dest_size + src_size;
 200         merged_buf = kmalloc(total, GFP_KERNEL);
 201         if (!merged_buf)
 202                 return -ENOMEM;
 203
 204         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 205         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 206         mrec = (struct pstore_ftrace_record *)(merged_buf);
 207
 208         while (dest_size > 0 && src_size > 0) {
 209                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 210                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 211                         mrec[merged_idx++] = drec[dest_idx++];
 212                         dest_size -= record_size;
 213                 } else {
 214                         mrec[merged_idx++] = srec[src_idx++];
 215                         src_size -= record_size;
 216                 }
 217         }
 218
 219         while (dest_size > 0) {
 220                 mrec[merged_idx++] = drec[dest_idx++];
 221                 dest_size -= record_size;
 222         }
 223
 224         while (src_size > 0) {
 225                 mrec[merged_idx++] = srec[src_idx++];
 226                 src_size -= record_size;
 227         }
 228
 229         kfree(dest->old_log);
 230         dest->old_log = merged_buf;
 231         dest->old_log_size = total;
 232
 233         return 0;
 234 }
 235
 236 static ssize_t ramoops_pstore_read(struct pstore_record *record)
 237 {
 238         ssize_t size = 0;
 239         struct ramoops_context *cxt = record->psi->data;
 240         struct persistent_ram_zone *prz = NULL;
 241         int header_length = 0;
 242         bool free_prz = false;
 243
 244         /*
 245          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 246          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 247          * valid time stamps, so it is initialized to zero.
 248          */
 249         record->time.tv_sec = 0;
 250         record->time.tv_nsec = 0;
 251         record->compressed = false;
 252
 253         /* Find the next valid persistent_ram_zone for DMESG */
 254         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 255                 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
 256                                            record);
 257                 if (!prz_ok(prz))
 258                         continue;
 259                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 260                                                       &record->time,
 261                                                       &record->compressed);
 262                 /* Clear and skip this DMESG record if it has no valid header */
 263                 if (!header_length) {
 264                         persistent_ram_free_old(prz);
 265                         persistent_ram_zap(prz);
 266                         prz = NULL;
 267                 }
 268         }
 269
 270         if (!prz_ok(prz) && !cxt->console_read_cnt++)
 271                 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
 272
 273         if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
 274                 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
 275
 276         /* ftrace is last since it may want to dynamically allocate memory. */
 277         if (!prz_ok(prz)) {
 278                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
 279                     !cxt->ftrace_read_cnt++) {
 280                         prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
 281                                                    record);
 282                 } else {
 283                         /*
 284                          * Build a new dummy record which combines all the
 285                          * per-cpu records including metadata and ecc info.
 286                          */
 287                         struct persistent_ram_zone *tmp_prz, *prz_next;
 288
 289                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 290                                           GFP_KERNEL);
 291                         if (!tmp_prz)
 292                                 return -ENOMEM;
 293                         prz = tmp_prz;
 294                         free_prz = true;
 295
 296                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 297                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 298                                                 cxt->ftrace_read_cnt++, record);
 299
 300                                 if (!prz_ok(prz_next))
 301                                         continue;
 302
 303                                 tmp_prz->ecc_info = prz_next->ecc_info;
 304                                 tmp_prz->corrected_bytes +=
 305                                                 prz_next->corrected_bytes;
 306                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 307                                 size = ftrace_log_combine(tmp_prz, prz_next);
 308                                 if (size)
 309                                         goto out;
 310                         }
 311                         record->id = 0;
 312                 }
 313         }
 314
 315         if (!prz_ok(prz)) {
 316                 size = 0;
 317                 goto out;
 318         }
 319
 320         size = persistent_ram_old_size(prz) - header_length;
 321
 322         /* ECC correction notice */
 323         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 324
 325         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 326         if (record->buf == NULL) {
 327                 size = -ENOMEM;
 328                 goto out;
 329         }
 330
 331         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 332                size);
 333
 334         persistent_ram_ecc_string(prz, record->buf + size,
 335                                   record->ecc_notice_size + 1);
 336
 337 out:
 338         if (free_prz) {
 339                 kfree(prz->old_log);
 340                 kfree(prz);
 341         }
 342
 343         return size;
 344 }
 345
 346 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 347                                      struct pstore_record *record)
 348 {
 349         char *hdr;
 350         size_t len;
 351
 352         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
 353                 (time64_t)record->time.tv_sec,
 354                 record->time.tv_nsec / 1000,
 355                 record->compressed ? 'C' : 'D');
 356         WARN_ON_ONCE(!hdr);
 357         len = hdr ? strlen(hdr) : 0;
 358         persistent_ram_write(prz, hdr, len);
 359         kfree(hdr);
 360
 361         return len;
 362 }
 363
 364 static int notrace ramoops_pstore_write(struct pstore_record *record)
 365 {
 366         struct ramoops_context *cxt = record->psi->data;
 367         struct persistent_ram_zone *prz;
 368         size_t size, hlen;
 369
 370         if (record->type == PSTORE_TYPE_CONSOLE) {
 371                 if (!cxt->cprz)
 372                         return -ENOMEM;
 373                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 374                 return 0;
 375         } else if (record->type == PSTORE_TYPE_FTRACE) {
 376                 int zonenum;
 377
 378                 if (!cxt->fprzs)
 379                         return -ENOMEM;
 380                 /*
 381                  * Choose zone by if we're using per-cpu buffers.
 382                  */
 383                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 384                         zonenum = smp_processor_id();
 385                 else
 386                         zonenum = 0;
 387
 388                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 389                                      record->size);
 390                 return 0;
 391         } else if (record->type == PSTORE_TYPE_PMSG) {
 392                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 393                 return -EINVAL;
 394         }
 395
 396         if (record->type != PSTORE_TYPE_DMESG)
 397                 return -EINVAL;
 398
 399         /*
 400          * Out of the various dmesg dump types, ramoops is currently designed
 401          * to only store crash logs, rather than storing general kernel logs.
 402          */
 403         if (record->reason != KMSG_DUMP_OOPS &&
 404             record->reason != KMSG_DUMP_PANIC)
 405                 return -EINVAL;
 406
 407         /* Skip Oopes when configured to do so. */
 408         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 409                 return -EINVAL;
 410
 411         /*
 412          * Explicitly only take the first part of any new crash.
 413          * If our buffer is larger than kmsg_bytes, this can never happen,
 414          * and if our buffer is smaller than kmsg_bytes, we don't want the
 415          * report split across multiple records.
 416          */
 417         if (record->part != 1)
 418                 return -ENOSPC;
 419
 420         if (!cxt->dprzs)
 421                 return -ENOSPC;
 422
 423         prz = cxt->dprzs[cxt->dump_write_cnt];
 424
 425         /* Build header and append record contents. */
 426         hlen = ramoops_write_kmsg_hdr(prz, record);
 427         size = record->size;
 428         if (size + hlen > prz->buffer_size)
 429                 size = prz->buffer_size - hlen;
 430         persistent_ram_write(prz, record->buf, size);
 431
 432         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 433
 434         return 0;
 435 }
 436
 437 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 438                                              const char __user *buf)
 439 {
 440         if (record->type == PSTORE_TYPE_PMSG) {
 441                 struct ramoops_context *cxt = record->psi->data;
 442
 443                 if (!cxt->mprz)
 444                         return -ENOMEM;
 445                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 446         }
 447
 448         return -EINVAL;
 449 }
 450
 451 static int ramoops_pstore_erase(struct pstore_record *record)
 452 {
 453         struct ramoops_context *cxt = record->psi->data;
 454         struct persistent_ram_zone *prz;
 455
 456         switch (record->type) {
 457         case PSTORE_TYPE_DMESG:
 458                 if (record->id >= cxt->max_dump_cnt)
 459                         return -EINVAL;
 460                 prz = cxt->dprzs[record->id];
 461                 break;
 462         case PSTORE_TYPE_CONSOLE:
 463                 prz = cxt->cprz;
 464                 break;
 465         case PSTORE_TYPE_FTRACE:
 466                 if (record->id >= cxt->max_ftrace_cnt)
 467                         return -EINVAL;
 468                 prz = cxt->fprzs[record->id];
 469                 break;
 470         case PSTORE_TYPE_PMSG:
 471                 prz = cxt->mprz;
 472                 break;
 473         default:
 474                 return -EINVAL;
 475         }
 476
 477         persistent_ram_free_old(prz);
 478         persistent_ram_zap(prz);
 479
 480         return 0;
 481 }
 482
 483 static struct ramoops_context oops_cxt = {
 484         .pstore = {
 485                 .owner  = THIS_MODULE,
 486                 .name   = "ramoops",
 487                 .open   = ramoops_pstore_open,
 488                 .read   = ramoops_pstore_read,
 489                 .write  = ramoops_pstore_write,
 490                 .write_user     = ramoops_pstore_write_user,
 491                 .erase  = ramoops_pstore_erase,
 492         },
 493 };
 494
 495 static void ramoops_free_przs(struct ramoops_context *cxt)
 496 {
 497         int i;
 498
 499         /* Free dump PRZs */
 500         if (cxt->dprzs) {
 501                 for (i = 0; i < cxt->max_dump_cnt; i++)
 502                         persistent_ram_free(cxt->dprzs[i]);
 503
 504                 kfree(cxt->dprzs);
 505                 cxt->max_dump_cnt = 0;
 506         }
 507
 508         /* Free ftrace PRZs */
 509         if (cxt->fprzs) {
 510                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 511                         persistent_ram_free(cxt->fprzs[i]);
 512                 kfree(cxt->fprzs);
 513                 cxt->max_ftrace_cnt = 0;
 514         }
 515 }
 516
 517 static int ramoops_init_przs(const char *name,
 518                              struct device *dev, struct ramoops_context *cxt,
 519                              struct persistent_ram_zone ***przs,
 520                              phys_addr_t *paddr, size_t mem_sz,
 521                              ssize_t record_size,
 522                              unsigned int *cnt, u32 sig, u32 flags)
 523 {
 524         int err = -ENOMEM;
 525         int i;
 526         size_t zone_sz;
 527         struct persistent_ram_zone **prz_ar;
 528
 529         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 530         if (mem_sz == 0 || record_size == 0) {
 531                 *cnt = 0;
 532                 return 0;
 533         }
 534
 535         /*
 536          * If we have a negative record size, calculate it based on
 537          * mem_sz / *cnt. If we have a positive record size, calculate
 538          * cnt from mem_sz / record_size.
 539          */
 540         if (record_size < 0) {
 541                 if (*cnt == 0)
 542                         return 0;
 543                 record_size = mem_sz / *cnt;
 544                 if (record_size == 0) {
 545                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 546                                 name, mem_sz, *cnt);
 547                         goto fail;
 548                 }
 549         } else {
 550                 *cnt = mem_sz / record_size;
 551                 if (*cnt == 0) {
 552                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 553                                 name, mem_sz, record_size);
 554                         goto fail;
 555                 }
 556         }
 557
 558         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 559                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 560                         name,
 561                         mem_sz, (unsigned long long)*paddr,
 562                         cxt->size, (unsigned long long)cxt->phys_addr);
 563                 goto fail;
 564         }
 565
 566         zone_sz = mem_sz / *cnt;
 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                 if (IS_ERR(prz_ar[i])) {
 588                         err = PTR_ERR(prz_ar[i]);
 589                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 590                                 name, record_size,
 591                                 (unsigned long long)*paddr, err);
 592
 593                         while (i > 0) {
 594                                 i--;
 595                                 persistent_ram_free(prz_ar[i]);
 596                         }
 597                         kfree(prz_ar);
 598                         goto fail;
 599                 }
 600                 *paddr += zone_sz;
 601                 prz_ar[i]->type = pstore_name_to_type(name);
 602         }
 603
 604         *przs = prz_ar;
 605         return 0;
 606
 607 fail:
 608         *cnt = 0;
 609         return err;
 610 }
 611
 612 static int ramoops_init_prz(const char *name,
 613                             struct device *dev, struct ramoops_context *cxt,
 614                             struct persistent_ram_zone **prz,
 615                             phys_addr_t *paddr, size_t sz, u32 sig)
 616 {
 617         char *label;
 618
 619         if (!sz)
 620                 return 0;
 621
 622         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 623                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 624                         name, sz, (unsigned long long)*paddr,
 625                         cxt->size, (unsigned long long)cxt->phys_addr);
 626                 return -ENOMEM;
 627         }
 628
 629         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 630         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 631                                   cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
 632         if (IS_ERR(*prz)) {
 633                 int err = PTR_ERR(*prz);
 634
 635                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 636                         name, sz, (unsigned long long)*paddr, err);
 637                 return err;
 638         }
 639
 640         *paddr += sz;
 641         (*prz)->type = pstore_name_to_type(name);
 642
 643         return 0;
 644 }
 645
 646 static int ramoops_parse_dt_size(struct platform_device *pdev,
 647                                  const char *propname, u32 *value)
 648 {
 649         u32 val32 = 0;
 650         int ret;
 651
 652         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 653         if (ret < 0 && ret != -EINVAL) {
 654                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 655                         propname, ret);
 656                 return ret;
 657         }
 658
 659         if (val32 > INT_MAX) {
 660                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 661                 return -EOVERFLOW;
 662         }
 663
 664         *value = val32;
 665         return 0;
 666 }
 667
 668 static int ramoops_parse_dt(struct platform_device *pdev,
 669                             struct ramoops_platform_data *pdata)
 670 {
 671         struct device_node *of_node = pdev->dev.of_node;
 672         struct resource *res;
 673         u32 value;
 674         int ret;
 675
 676         dev_dbg(&pdev->dev, "using Device Tree\n");
 677
 678         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 679         if (!res) {
 680                 dev_err(&pdev->dev,
 681                         "failed to locate DT /reserved-memory resource\n");
 682                 return -EINVAL;
 683         }
 684
 685         pdata->mem_size = resource_size(res);
 686         pdata->mem_address = res->start;
 687         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 688         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 689
 690 #define parse_size(name, field) {                                       \
 691                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 692                 if (ret < 0)                                            \
 693                         return ret;                                     \
 694                 field = value;                                          \
 695         }
 696
 697         parse_size("record-size", pdata->record_size);
 698         parse_size("console-size", pdata->console_size);
 699         parse_size("ftrace-size", pdata->ftrace_size);
 700         parse_size("pmsg-size", pdata->pmsg_size);
 701         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 702         parse_size("flags", pdata->flags);
 703
 704 #undef parse_size
 705
 706         return 0;
 707 }
 708
 709 static int ramoops_probe(struct platform_device *pdev)
 710 {
 711         struct device *dev = &pdev->dev;
 712         struct ramoops_platform_data *pdata = dev->platform_data;
 713         struct ramoops_platform_data pdata_local;
 714         struct ramoops_context *cxt = &oops_cxt;
 715         size_t dump_mem_sz;
 716         phys_addr_t paddr;
 717         int err = -EINVAL;
 718
 719         if (dev_of_node(dev) && !pdata) {
 720                 pdata = &pdata_local;
 721                 memset(pdata, 0, sizeof(*pdata));
 722
 723                 err = ramoops_parse_dt(pdev, pdata);
 724                 if (err < 0)
 725                         goto fail_out;
 726         }
 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         /* Make sure we didn't get bogus platform data pointer. */
 738         if (!pdata) {
 739                 pr_err("NULL platform data\n");
 740                 goto fail_out;
 741         }
 742
 743         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 744                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 745                 pr_err("The memory size and the record/console size must be "
 746                         "non-zero\n");
 747                 goto fail_out;
 748         }
 749
 750         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 751                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 752         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 753                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 754         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 755                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 756         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 757                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 758
 759         cxt->size = pdata->mem_size;
 760         cxt->phys_addr = pdata->mem_address;
 761         cxt->memtype = pdata->mem_type;
 762         cxt->record_size = pdata->record_size;
 763         cxt->console_size = pdata->console_size;
 764         cxt->ftrace_size = pdata->ftrace_size;
 765         cxt->pmsg_size = pdata->pmsg_size;
 766         cxt->dump_oops = pdata->dump_oops;
 767         cxt->flags = pdata->flags;
 768         cxt->ecc_info = pdata->ecc_info;
 769
 770         paddr = cxt->phys_addr;
 771
 772         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 773                         - cxt->pmsg_size;
 774         err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
 775                                 dump_mem_sz, cxt->record_size,
 776                                 &cxt->max_dump_cnt, 0, 0);
 777         if (err)
 778                 goto fail_out;
 779
 780         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 781                                cxt->console_size, 0);
 782         if (err)
 783                 goto fail_init_cprz;
 784
 785         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 786                                 ? nr_cpu_ids
 787                                 : 1;
 788         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 789                                 cxt->ftrace_size, -1,
 790                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 791                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 792                                         ? PRZ_FLAG_NO_LOCK : 0);
 793         if (err)
 794                 goto fail_init_fprz;
 795
 796         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 797                                 cxt->pmsg_size, 0);
 798         if (err)
 799                 goto fail_init_mprz;
 800
 801         cxt->pstore.data = cxt;
 802         /*
 803          * Since bufsize is only used for dmesg crash dumps, it
 804          * must match the size of the dprz record (after PRZ header
 805          * and ECC bytes have been accounted for).
 806          */
 807         cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
 808         cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
 809         if (!cxt->pstore.buf) {
 810                 pr_err("cannot allocate pstore crash dump buffer\n");
 811                 err = -ENOMEM;
 812                 goto fail_clear;
 813         }
 814
 815         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 816         if (cxt->console_size)
 817                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 818         if (cxt->ftrace_size)
 819                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 820         if (cxt->pmsg_size)
 821                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 822
 823         err = pstore_register(&cxt->pstore);
 824         if (err) {
 825                 pr_err("registering with pstore failed\n");
 826                 goto fail_buf;
 827         }
 828
 829         /*
 830          * Update the module parameter variables as well so they are visible
 831          * through /sys/module/ramoops/parameters/
 832          */
 833         mem_size = pdata->mem_size;
 834         mem_address = pdata->mem_address;
 835         record_size = pdata->record_size;
 836         dump_oops = pdata->dump_oops;
 837         ramoops_console_size = pdata->console_size;
 838         ramoops_pmsg_size = pdata->pmsg_size;
 839         ramoops_ftrace_size = pdata->ftrace_size;
 840
 841         pr_info("using 0x%lx@0x%llx, ecc: %d\n",
 842                 cxt->size, (unsigned long long)cxt->phys_addr,
 843                 cxt->ecc_info.ecc_size);
 844
 845         return 0;
 846
 847 fail_buf:
 848         kfree(cxt->pstore.buf);
 849 fail_clear:
 850         cxt->pstore.bufsize = 0;
 851         persistent_ram_free(cxt->mprz);
 852 fail_init_mprz:
 853 fail_init_fprz:
 854         persistent_ram_free(cxt->cprz);
 855 fail_init_cprz:
 856         ramoops_free_przs(cxt);
 857 fail_out:
 858         return err;
 859 }
 860
 861 static int ramoops_remove(struct platform_device *pdev)
 862 {
 863         struct ramoops_context *cxt = &oops_cxt;
 864
 865         pstore_unregister(&cxt->pstore);
 866
 867         kfree(cxt->pstore.buf);
 868         cxt->pstore.bufsize = 0;
 869
 870         persistent_ram_free(cxt->mprz);
 871         persistent_ram_free(cxt->cprz);
 872         ramoops_free_przs(cxt);
 873
 874         return 0;
 875 }
 876
 877 static const struct of_device_id dt_match[] = {
 878         { .compatible = "ramoops" },
 879         {}
 880 };
 881
 882 static struct platform_driver ramoops_driver = {
 883         .probe          = ramoops_probe,
 884         .remove         = ramoops_remove,
 885         .driver         = {
 886                 .name           = "ramoops",
 887                 .of_match_table = dt_match,
 888         },
 889 };
 890
 891 static inline void ramoops_unregister_dummy(void)
 892 {
 893         platform_device_unregister(dummy);
 894         dummy = NULL;
 895
 896         kfree(dummy_data);
 897         dummy_data = NULL;
 898 }
 899
 900 static void __init ramoops_register_dummy(void)
 901 {
 902         /*
 903          * Prepare a dummy platform data structure to carry the module
 904          * parameters. If mem_size isn't set, then there are no module
 905          * parameters, and we can skip this.
 906          */
 907         if (!mem_size)
 908                 return;
 909
 910         pr_info("using module parameters\n");
 911
 912         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 913         if (!dummy_data) {
 914                 pr_info("could not allocate pdata\n");
 915                 return;
 916         }
 917
 918         dummy_data->mem_size = mem_size;
 919         dummy_data->mem_address = mem_address;
 920         dummy_data->mem_type = mem_type;
 921         dummy_data->record_size = record_size;
 922         dummy_data->console_size = ramoops_console_size;
 923         dummy_data->ftrace_size = ramoops_ftrace_size;
 924         dummy_data->pmsg_size = ramoops_pmsg_size;
 925         dummy_data->dump_oops = dump_oops;
 926         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 927
 928         /*
 929          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 930          * (using 1 byte for ECC isn't much of use anyway).
 931          */
 932         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 933
 934         dummy = platform_device_register_data(NULL, "ramoops", -1,
 935                         dummy_data, sizeof(struct ramoops_platform_data));
 936         if (IS_ERR(dummy)) {
 937                 pr_info("could not create platform device: %ld\n",
 938                         PTR_ERR(dummy));
 939                 dummy = NULL;
 940                 ramoops_unregister_dummy();
 941         }
 942 }
 943
 944 static int __init ramoops_init(void)
 945 {
 946         int ret;
 947
 948         ramoops_register_dummy();
 949         ret = platform_driver_register(&ramoops_driver);
 950         if (ret != 0)
 951                 ramoops_unregister_dummy();
 952
 953         return ret;
 954 }
 955 postcore_initcall(ramoops_init);
 956
 957 static void __exit ramoops_exit(void)
 958 {
 959         platform_driver_unregister(&ramoops_driver);
 960         ramoops_unregister_dummy();
 961 }
 962 module_exit(ramoops_exit);
 963
 964 MODULE_LICENSE("GPL");
 965 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 966 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");