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/time.h>
  31 #include <linux/io.h>
  32 #include <linux/ioport.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/slab.h>
  35 #include <linux/compiler.h>
  36 #include <linux/pstore_ram.h>
  37
  38 #define RAMOOPS_KERNMSG_HDR "===="
  39 #define MIN_MEM_SIZE 4096UL
  40
  41 static ulong record_size = MIN_MEM_SIZE;
  42 module_param(record_size, ulong, 0400);
  43 MODULE_PARM_DESC(record_size,
  44                 "size of each dump done on oops/panic");
  45
  46 static ulong ramoops_console_size = MIN_MEM_SIZE;
  47 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  48 MODULE_PARM_DESC(console_size, "size of kernel console log");
  49
  50 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  51 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  52 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  53
  54 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  55 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  56 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  57
  58 static ulong mem_address;
  59 module_param(mem_address, ulong, 0400);
  60 MODULE_PARM_DESC(mem_address,
  61                 "start of reserved RAM used to store oops/panic logs");
  62
  63 static ulong mem_size;
  64 module_param(mem_size, ulong, 0400);
  65 MODULE_PARM_DESC(mem_size,
  66                 "size of reserved RAM used to store oops/panic logs");
  67
  68 static unsigned int mem_type;
  69 module_param(mem_type, uint, 0600);
  70 MODULE_PARM_DESC(mem_type,
  71                 "set to 1 to try to use unbuffered memory (default 0)");
  72
  73 static int dump_oops = 1;
  74 module_param(dump_oops, int, 0600);
  75 MODULE_PARM_DESC(dump_oops,
  76                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  77
  78 static int ramoops_ecc;
  79 module_param_named(ecc, ramoops_ecc, int, 0600);
  80 MODULE_PARM_DESC(ramoops_ecc,
  81                 "if non-zero, the option enables ECC support and specifies "
  82                 "ECC buffer size in bytes (1 is a special value, means 16 "
  83                 "bytes ECC)");
  84
  85 struct ramoops_context {
  86         struct persistent_ram_zone **przs;
  87         struct persistent_ram_zone *cprz;
  88         struct persistent_ram_zone *fprz;
  89         struct persistent_ram_zone *mprz;
  90         phys_addr_t phys_addr;
  91         unsigned long size;
  92         unsigned int memtype;
  93         size_t record_size;
  94         size_t console_size;
  95         size_t ftrace_size;
  96         size_t pmsg_size;
  97         int dump_oops;
  98         struct persistent_ram_ecc_info ecc_info;
  99         unsigned int max_dump_cnt;
 100         unsigned int dump_write_cnt;
 101         /* _read_cnt need clear on ramoops_pstore_open */
 102         unsigned int dump_read_cnt;
 103         unsigned int console_read_cnt;
 104         unsigned int ftrace_read_cnt;
 105         unsigned int pmsg_read_cnt;
 106         struct pstore_info pstore;
 107 };
 108
 109 static struct platform_device *dummy;
 110 static struct ramoops_platform_data *dummy_data;
 111
 112 static int ramoops_pstore_open(struct pstore_info *psi)
 113 {
 114         struct ramoops_context *cxt = psi->data;
 115
 116         cxt->dump_read_cnt = 0;
 117         cxt->console_read_cnt = 0;
 118         cxt->ftrace_read_cnt = 0;
 119         cxt->pmsg_read_cnt = 0;
 120         return 0;
 121 }
 122
 123 static struct persistent_ram_zone *
 124 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 125                      u64 *id,
 126                      enum pstore_type_id *typep, enum pstore_type_id type,
 127                      bool update)
 128 {
 129         struct persistent_ram_zone *prz;
 130         int i = (*c)++;
 131
 132         if (i >= max)
 133                 return NULL;
 134
 135         prz = przs[i];
 136         if (!prz)
 137                 return NULL;
 138
 139         /* Update old/shadowed buffer. */
 140         if (update)
 141                 persistent_ram_save_old(prz);
 142
 143         if (!persistent_ram_old_size(prz))
 144                 return NULL;
 145
 146         *typep = type;
 147         *id = i;
 148
 149         return prz;
 150 }
 151
 152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 153                                   bool *compressed)
 154 {
 155         char data_type;
 156         int header_length = 0;
 157
 158         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 159                         &time->tv_nsec, &data_type, &header_length) == 3) {
 160                 if (data_type == 'C')
 161                         *compressed = true;
 162                 else
 163                         *compressed = false;
 164         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 165                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
 166                         *compressed = false;
 167         } else {
 168                 time->tv_sec = 0;
 169                 time->tv_nsec = 0;
 170                 *compressed = false;
 171         }
 172         return header_length;
 173 }
 174
 175 static bool prz_ok(struct persistent_ram_zone *prz)
 176 {
 177         return !!prz && !!(persistent_ram_old_size(prz) +
 178                            persistent_ram_ecc_string(prz, NULL, 0));
 179 }
 180
 181 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 182                                    int *count, struct timespec *time,
 183                                    char **buf, bool *compressed,
 184                                    struct pstore_info *psi)
 185 {
 186         ssize_t size;
 187         ssize_t ecc_notice_size;
 188         struct ramoops_context *cxt = psi->data;
 189         struct persistent_ram_zone *prz = NULL;
 190         int header_length = 0;
 191
 192         /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 193          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 194          * valid time stamps, so it is initialized to zero.
 195          */
 196         time->tv_sec = 0;
 197         time->tv_nsec = 0;
 198         *compressed = false;
 199
 200         /* Find the next valid persistent_ram_zone for DMESG */
 201         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 202                 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
 203                                            cxt->max_dump_cnt, id, type,
 204                                            PSTORE_TYPE_DMESG, 1);
 205                 if (!prz_ok(prz))
 206                         continue;
 207                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 208                                                       time, compressed);
 209                 /* Clear and skip this DMESG record if it has no valid header */
 210                 if (!header_length) {
 211                         persistent_ram_free_old(prz);
 212                         persistent_ram_zap(prz);
 213                         prz = NULL;
 214                 }
 215         }
 216
 217         if (!prz_ok(prz))
 218                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 219                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 220         if (!prz_ok(prz))
 221                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
 222                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
 223         if (!prz_ok(prz))
 224                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 225                                            1, id, type, PSTORE_TYPE_PMSG, 0);
 226         if (!prz_ok(prz))
 227                 return 0;
 228
 229         size = persistent_ram_old_size(prz) - header_length;
 230
 231         /* ECC correction notice */
 232         ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 233
 234         *buf = kmalloc(size + ecc_notice_size + 1, GFP_KERNEL);
 235         if (*buf == NULL)
 236                 return -ENOMEM;
 237
 238         memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
 239         persistent_ram_ecc_string(prz, *buf + size, ecc_notice_size + 1);
 240
 241         return size + ecc_notice_size;
 242 }
 243
 244 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 245                                      bool compressed)
 246 {
 247         char *hdr;
 248         struct timespec timestamp;
 249         size_t len;
 250
 251         /* Report zeroed timestamp if called before timekeeping has resumed. */
 252         if (__getnstimeofday(&timestamp)) {
 253                 timestamp.tv_sec = 0;
 254                 timestamp.tv_nsec = 0;
 255         }
 256         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 257                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
 258                 compressed ? 'C' : 'D');
 259         WARN_ON_ONCE(!hdr);
 260         len = hdr ? strlen(hdr) : 0;
 261         persistent_ram_write(prz, hdr, len);
 262         kfree(hdr);
 263
 264         return len;
 265 }
 266
 267 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 268                                             enum kmsg_dump_reason reason,
 269                                             u64 *id, unsigned int part,
 270                                             const char *buf,
 271                                             bool compressed, size_t size,
 272                                             struct pstore_info *psi)
 273 {
 274         struct ramoops_context *cxt = psi->data;
 275         struct persistent_ram_zone *prz;
 276         size_t hlen;
 277
 278         if (type == PSTORE_TYPE_CONSOLE) {
 279                 if (!cxt->cprz)
 280                         return -ENOMEM;
 281                 persistent_ram_write(cxt->cprz, buf, size);
 282                 return 0;
 283         } else if (type == PSTORE_TYPE_FTRACE) {
 284                 if (!cxt->fprz)
 285                         return -ENOMEM;
 286                 persistent_ram_write(cxt->fprz, buf, size);
 287                 return 0;
 288         } else if (type == PSTORE_TYPE_PMSG) {
 289                 if (!cxt->mprz)
 290                         return -ENOMEM;
 291                 persistent_ram_write(cxt->mprz, buf, size);
 292                 return 0;
 293         }
 294
 295         if (type != PSTORE_TYPE_DMESG)
 296                 return -EINVAL;
 297
 298         /* Out of the various dmesg dump types, ramoops is currently designed
 299          * to only store crash logs, rather than storing general kernel logs.
 300          */
 301         if (reason != KMSG_DUMP_OOPS &&
 302             reason != KMSG_DUMP_PANIC)
 303                 return -EINVAL;
 304
 305         /* Skip Oopes when configured to do so. */
 306         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 307                 return -EINVAL;
 308
 309         /* Explicitly only take the first part of any new crash.
 310          * If our buffer is larger than kmsg_bytes, this can never happen,
 311          * and if our buffer is smaller than kmsg_bytes, we don't want the
 312          * report split across multiple records.
 313          */
 314         if (part != 1)
 315                 return -ENOSPC;
 316
 317         if (!cxt->przs)
 318                 return -ENOSPC;
 319
 320         prz = cxt->przs[cxt->dump_write_cnt];
 321
 322         hlen = ramoops_write_kmsg_hdr(prz, compressed);
 323         if (size + hlen > prz->buffer_size)
 324                 size = prz->buffer_size - hlen;
 325         persistent_ram_write(prz, buf, size);
 326
 327         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 328
 329         return 0;
 330 }
 331
 332 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 333                                 struct timespec time, struct pstore_info *psi)
 334 {
 335         struct ramoops_context *cxt = psi->data;
 336         struct persistent_ram_zone *prz;
 337
 338         switch (type) {
 339         case PSTORE_TYPE_DMESG:
 340                 if (id >= cxt->max_dump_cnt)
 341                         return -EINVAL;
 342                 prz = cxt->przs[id];
 343                 break;
 344         case PSTORE_TYPE_CONSOLE:
 345                 prz = cxt->cprz;
 346                 break;
 347         case PSTORE_TYPE_FTRACE:
 348                 prz = cxt->fprz;
 349                 break;
 350         case PSTORE_TYPE_PMSG:
 351                 prz = cxt->mprz;
 352                 break;
 353         default:
 354                 return -EINVAL;
 355         }
 356
 357         persistent_ram_free_old(prz);
 358         persistent_ram_zap(prz);
 359
 360         return 0;
 361 }
 362
 363 static struct ramoops_context oops_cxt = {
 364         .pstore = {
 365                 .owner  = THIS_MODULE,
 366                 .name   = "ramoops",
 367                 .open   = ramoops_pstore_open,
 368                 .read   = ramoops_pstore_read,
 369                 .write_buf      = ramoops_pstore_write_buf,
 370                 .erase  = ramoops_pstore_erase,
 371         },
 372 };
 373
 374 static void ramoops_free_przs(struct ramoops_context *cxt)
 375 {
 376         int i;
 377
 378         if (!cxt->przs)
 379                 return;
 380
 381         for (i = 0; i < cxt->max_dump_cnt; i++)
 382                 persistent_ram_free(cxt->przs[i]);
 383
 384         kfree(cxt->przs);
 385         cxt->max_dump_cnt = 0;
 386 }
 387
 388 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
 389                              phys_addr_t *paddr, size_t dump_mem_sz)
 390 {
 391         int err = -ENOMEM;
 392         int i;
 393
 394         if (!cxt->record_size)
 395                 return 0;
 396
 397         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
 398                 dev_err(dev, "no room for dumps\n");
 399                 return -ENOMEM;
 400         }
 401
 402         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
 403         if (!cxt->max_dump_cnt)
 404                 return -ENOMEM;
 405
 406         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
 407                              GFP_KERNEL);
 408         if (!cxt->przs) {
 409                 dev_err(dev, "failed to initialize a prz array for dumps\n");
 410                 goto fail_mem;
 411         }
 412
 413         for (i = 0; i < cxt->max_dump_cnt; i++) {
 414                 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
 415                                                   &cxt->ecc_info,
 416                                                   cxt->memtype);
 417                 if (IS_ERR(cxt->przs[i])) {
 418                         err = PTR_ERR(cxt->przs[i]);
 419                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 420                                 cxt->record_size, (unsigned long long)*paddr, err);
 421
 422                         while (i > 0) {
 423                                 i--;
 424                                 persistent_ram_free(cxt->przs[i]);
 425                         }
 426                         goto fail_prz;
 427                 }
 428                 *paddr += cxt->record_size;
 429         }
 430
 431         return 0;
 432 fail_prz:
 433         kfree(cxt->przs);
 434 fail_mem:
 435         cxt->max_dump_cnt = 0;
 436         return err;
 437 }
 438
 439 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
 440                             struct persistent_ram_zone **prz,
 441                             phys_addr_t *paddr, size_t sz, u32 sig)
 442 {
 443         if (!sz)
 444                 return 0;
 445
 446         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 447                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 448                         sz, (unsigned long long)*paddr,
 449                         cxt->size, (unsigned long long)cxt->phys_addr);
 450                 return -ENOMEM;
 451         }
 452
 453         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
 454         if (IS_ERR(*prz)) {
 455                 int err = PTR_ERR(*prz);
 456
 457                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 458                         sz, (unsigned long long)*paddr, err);
 459                 return err;
 460         }
 461
 462         persistent_ram_zap(*prz);
 463
 464         *paddr += sz;
 465
 466         return 0;
 467 }
 468
 469 static int ramoops_probe(struct platform_device *pdev)
 470 {
 471         struct device *dev = &pdev->dev;
 472         struct ramoops_platform_data *pdata = pdev->dev.platform_data;
 473         struct ramoops_context *cxt = &oops_cxt;
 474         size_t dump_mem_sz;
 475         phys_addr_t paddr;
 476         int err = -EINVAL;
 477
 478         /* Only a single ramoops area allowed at a time, so fail extra
 479          * probes.
 480          */
 481         if (cxt->max_dump_cnt)
 482                 goto fail_out;
 483
 484         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 485                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 486                 pr_err("The memory size and the record/console size must be "
 487                         "non-zero\n");
 488                 goto fail_out;
 489         }
 490
 491         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 492                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 493         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 494                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 495         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 496                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 497         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 498                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 499
 500         cxt->size = pdata->mem_size;
 501         cxt->phys_addr = pdata->mem_address;
 502         cxt->memtype = pdata->mem_type;
 503         cxt->record_size = pdata->record_size;
 504         cxt->console_size = pdata->console_size;
 505         cxt->ftrace_size = pdata->ftrace_size;
 506         cxt->pmsg_size = pdata->pmsg_size;
 507         cxt->dump_oops = pdata->dump_oops;
 508         cxt->ecc_info = pdata->ecc_info;
 509
 510         paddr = cxt->phys_addr;
 511
 512         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 513                         - cxt->pmsg_size;
 514         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 515         if (err)
 516                 goto fail_out;
 517
 518         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 519                                cxt->console_size, 0);
 520         if (err)
 521                 goto fail_init_cprz;
 522
 523         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 524                                LINUX_VERSION_CODE);
 525         if (err)
 526                 goto fail_init_fprz;
 527
 528         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
 529         if (err)
 530                 goto fail_init_mprz;
 531
 532         cxt->pstore.data = cxt;
 533         /*
 534          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 535          * have to handle dumps, we must have at least record_size buffer. And
 536          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 537          * ZERO_SIZE_PTR).
 538          */
 539         if (cxt->console_size)
 540                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 541         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 542         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 543         spin_lock_init(&cxt->pstore.buf_lock);
 544         if (!cxt->pstore.buf) {
 545                 pr_err("cannot allocate pstore buffer\n");
 546                 err = -ENOMEM;
 547                 goto fail_clear;
 548         }
 549
 550         err = pstore_register(&cxt->pstore);
 551         if (err) {
 552                 pr_err("registering with pstore failed\n");
 553                 goto fail_buf;
 554         }
 555
 556         /*
 557          * Update the module parameter variables as well so they are visible
 558          * through /sys/module/ramoops/parameters/
 559          */
 560         mem_size = pdata->mem_size;
 561         mem_address = pdata->mem_address;
 562         record_size = pdata->record_size;
 563         dump_oops = pdata->dump_oops;
 564         ramoops_console_size = pdata->console_size;
 565         ramoops_pmsg_size = pdata->pmsg_size;
 566         ramoops_ftrace_size = pdata->ftrace_size;
 567
 568         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 569                 cxt->size, (unsigned long long)cxt->phys_addr,
 570                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 571
 572         return 0;
 573
 574 fail_buf:
 575         kfree(cxt->pstore.buf);
 576 fail_clear:
 577         cxt->pstore.bufsize = 0;
 578         kfree(cxt->mprz);
 579 fail_init_mprz:
 580         kfree(cxt->fprz);
 581 fail_init_fprz:
 582         kfree(cxt->cprz);
 583 fail_init_cprz:
 584         ramoops_free_przs(cxt);
 585 fail_out:
 586         return err;
 587 }
 588
 589 static int ramoops_remove(struct platform_device *pdev)
 590 {
 591         struct ramoops_context *cxt = &oops_cxt;
 592
 593         pstore_unregister(&cxt->pstore);
 594
 595         kfree(cxt->pstore.buf);
 596         cxt->pstore.bufsize = 0;
 597
 598         persistent_ram_free(cxt->mprz);
 599         persistent_ram_free(cxt->fprz);
 600         persistent_ram_free(cxt->cprz);
 601         ramoops_free_przs(cxt);
 602
 603         return 0;
 604 }
 605
 606 static struct platform_driver ramoops_driver = {
 607         .probe          = ramoops_probe,
 608         .remove         = ramoops_remove,
 609         .driver         = {
 610                 .name   = "ramoops",
 611         },
 612 };
 613
 614 static void ramoops_register_dummy(void)
 615 {
 616         if (!mem_size)
 617                 return;
 618
 619         pr_info("using module parameters\n");
 620
 621         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 622         if (!dummy_data) {
 623                 pr_info("could not allocate pdata\n");
 624                 return;
 625         }
 626
 627         dummy_data->mem_size = mem_size;
 628         dummy_data->mem_address = mem_address;
 629         dummy_data->mem_type = mem_type;
 630         dummy_data->record_size = record_size;
 631         dummy_data->console_size = ramoops_console_size;
 632         dummy_data->ftrace_size = ramoops_ftrace_size;
 633         dummy_data->pmsg_size = ramoops_pmsg_size;
 634         dummy_data->dump_oops = dump_oops;
 635         /*
 636          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 637          * (using 1 byte for ECC isn't much of use anyway).
 638          */
 639         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 640
 641         dummy = platform_device_register_data(NULL, "ramoops", -1,
 642                         dummy_data, sizeof(struct ramoops_platform_data));
 643         if (IS_ERR(dummy)) {
 644                 pr_info("could not create platform device: %ld\n",
 645                         PTR_ERR(dummy));
 646         }
 647 }
 648
 649 static int __init ramoops_init(void)
 650 {
 651         ramoops_register_dummy();
 652         return platform_driver_register(&ramoops_driver);
 653 }
 654 postcore_initcall(ramoops_init);
 655
 656 static void __exit ramoops_exit(void)
 657 {
 658         platform_driver_unregister(&ramoops_driver);
 659         platform_device_unregister(dummy);
 660         kfree(dummy_data);
 661 }
 662 module_exit(ramoops_exit);
 663
 664 MODULE_LICENSE("GPL");
 665 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 666 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");