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 #include <linux/of.h>
  38 #include <linux/of_address.h>
  39
  40 #define RAMOOPS_KERNMSG_HDR "===="
  41 #define MIN_MEM_SIZE 4096UL
  42
  43 static ulong record_size = MIN_MEM_SIZE;
  44 module_param(record_size, ulong, 0400);
  45 MODULE_PARM_DESC(record_size,
  46                 "size of each dump done on oops/panic");
  47
  48 static ulong ramoops_console_size = MIN_MEM_SIZE;
  49 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  50 MODULE_PARM_DESC(console_size, "size of kernel console log");
  51
  52 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  53 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  54 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  55
  56 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  57 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  58 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  59
  60 static unsigned long long mem_address;
  61 module_param(mem_address, ullong, 0400);
  62 MODULE_PARM_DESC(mem_address,
  63                 "start of reserved RAM used to store oops/panic logs");
  64
  65 static ulong mem_size;
  66 module_param(mem_size, ulong, 0400);
  67 MODULE_PARM_DESC(mem_size,
  68                 "size of reserved RAM used to store oops/panic logs");
  69
  70 static unsigned int mem_type;
  71 module_param(mem_type, uint, 0600);
  72 MODULE_PARM_DESC(mem_type,
  73                 "set to 1 to try to use unbuffered memory (default 0)");
  74
  75 static int dump_oops = 1;
  76 module_param(dump_oops, int, 0600);
  77 MODULE_PARM_DESC(dump_oops,
  78                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  79
  80 static int ramoops_ecc;
  81 module_param_named(ecc, ramoops_ecc, int, 0600);
  82 MODULE_PARM_DESC(ramoops_ecc,
  83                 "if non-zero, the option enables ECC support and specifies "
  84                 "ECC buffer size in bytes (1 is a special value, means 16 "
  85                 "bytes ECC)");
  86
  87 struct ramoops_context {
  88         struct persistent_ram_zone **przs;
  89         struct persistent_ram_zone *cprz;
  90         struct persistent_ram_zone *fprz;
  91         struct persistent_ram_zone *mprz;
  92         phys_addr_t phys_addr;
  93         unsigned long size;
  94         unsigned int memtype;
  95         size_t record_size;
  96         size_t console_size;
  97         size_t ftrace_size;
  98         size_t pmsg_size;
  99         int dump_oops;
 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 ftrace_read_cnt;
 107         unsigned int pmsg_read_cnt;
 108         struct pstore_info pstore;
 109 };
 110
 111 static struct platform_device *dummy;
 112 static struct ramoops_platform_data *dummy_data;
 113
 114 static int ramoops_pstore_open(struct pstore_info *psi)
 115 {
 116         struct ramoops_context *cxt = psi->data;
 117
 118         cxt->dump_read_cnt = 0;
 119         cxt->console_read_cnt = 0;
 120         cxt->ftrace_read_cnt = 0;
 121         cxt->pmsg_read_cnt = 0;
 122         return 0;
 123 }
 124
 125 static struct persistent_ram_zone *
 126 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 127                      u64 *id,
 128                      enum pstore_type_id *typep, enum pstore_type_id type,
 129                      bool update)
 130 {
 131         struct persistent_ram_zone *prz;
 132         int i = (*c)++;
 133
 134         if (i >= max)
 135                 return NULL;
 136
 137         prz = przs[i];
 138         if (!prz)
 139                 return NULL;
 140
 141         /* Update old/shadowed buffer. */
 142         if (update)
 143                 persistent_ram_save_old(prz);
 144
 145         if (!persistent_ram_old_size(prz))
 146                 return NULL;
 147
 148         *typep = type;
 149         *id = i;
 150
 151         return prz;
 152 }
 153
 154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 155                                   bool *compressed)
 156 {
 157         char data_type;
 158         int header_length = 0;
 159
 160         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 161                         &time->tv_nsec, &data_type, &header_length) == 3) {
 162                 if (data_type == 'C')
 163                         *compressed = true;
 164                 else
 165                         *compressed = false;
 166         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 167                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
 168                         *compressed = false;
 169         } else {
 170                 time->tv_sec = 0;
 171                 time->tv_nsec = 0;
 172                 *compressed = false;
 173         }
 174         return header_length;
 175 }
 176
 177 static bool prz_ok(struct persistent_ram_zone *prz)
 178 {
 179         return !!prz && !!(persistent_ram_old_size(prz) +
 180                            persistent_ram_ecc_string(prz, NULL, 0));
 181 }
 182
 183 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 184                                    int *count, struct timespec *time,
 185                                    char **buf, bool *compressed,
 186                                    ssize_t *ecc_notice_size,
 187                                    struct pstore_info *psi)
 188 {
 189         ssize_t size;
 190         struct ramoops_context *cxt = psi->data;
 191         struct persistent_ram_zone *prz = NULL;
 192         int header_length = 0;
 193
 194         /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 195          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 196          * valid time stamps, so it is initialized to zero.
 197          */
 198         time->tv_sec = 0;
 199         time->tv_nsec = 0;
 200         *compressed = false;
 201
 202         /* Find the next valid persistent_ram_zone for DMESG */
 203         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 204                 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
 205                                            cxt->max_dump_cnt, id, type,
 206                                            PSTORE_TYPE_DMESG, 1);
 207                 if (!prz_ok(prz))
 208                         continue;
 209                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 210                                                       time, compressed);
 211                 /* Clear and skip this DMESG record if it has no valid header */
 212                 if (!header_length) {
 213                         persistent_ram_free_old(prz);
 214                         persistent_ram_zap(prz);
 215                         prz = NULL;
 216                 }
 217         }
 218
 219         if (!prz_ok(prz))
 220                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 221                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 222         if (!prz_ok(prz))
 223                 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
 224                                            1, id, type, PSTORE_TYPE_FTRACE, 0);
 225         if (!prz_ok(prz))
 226                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 227                                            1, id, type, PSTORE_TYPE_PMSG, 0);
 228         if (!prz_ok(prz))
 229                 return 0;
 230
 231         size = persistent_ram_old_size(prz) - header_length;
 232
 233         /* ECC correction notice */
 234         *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 235
 236         *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
 237         if (*buf == NULL)
 238                 return -ENOMEM;
 239
 240         memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
 241         persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
 242
 243         return size;
 244 }
 245
 246 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 247                                      bool compressed)
 248 {
 249         char *hdr;
 250         struct timespec timestamp;
 251         size_t len;
 252
 253         /* Report zeroed timestamp if called before timekeeping has resumed. */
 254         if (__getnstimeofday(&timestamp)) {
 255                 timestamp.tv_sec = 0;
 256                 timestamp.tv_nsec = 0;
 257         }
 258         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 259                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
 260                 compressed ? 'C' : 'D');
 261         WARN_ON_ONCE(!hdr);
 262         len = hdr ? strlen(hdr) : 0;
 263         persistent_ram_write(prz, hdr, len);
 264         kfree(hdr);
 265
 266         return len;
 267 }
 268
 269 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 270                                             enum kmsg_dump_reason reason,
 271                                             u64 *id, unsigned int part,
 272                                             const char *buf,
 273                                             bool compressed, size_t size,
 274                                             struct pstore_info *psi)
 275 {
 276         struct ramoops_context *cxt = psi->data;
 277         struct persistent_ram_zone *prz;
 278         size_t hlen;
 279
 280         if (type == PSTORE_TYPE_CONSOLE) {
 281                 if (!cxt->cprz)
 282                         return -ENOMEM;
 283                 persistent_ram_write(cxt->cprz, buf, size);
 284                 return 0;
 285         } else if (type == PSTORE_TYPE_FTRACE) {
 286                 if (!cxt->fprz)
 287                         return -ENOMEM;
 288                 persistent_ram_write(cxt->fprz, buf, size);
 289                 return 0;
 290         } else if (type == PSTORE_TYPE_PMSG) {
 291                 if (!cxt->mprz)
 292                         return -ENOMEM;
 293                 persistent_ram_write(cxt->mprz, buf, size);
 294                 return 0;
 295         }
 296
 297         if (type != PSTORE_TYPE_DMESG)
 298                 return -EINVAL;
 299
 300         /* Out of the various dmesg dump types, ramoops is currently designed
 301          * to only store crash logs, rather than storing general kernel logs.
 302          */
 303         if (reason != KMSG_DUMP_OOPS &&
 304             reason != KMSG_DUMP_PANIC)
 305                 return -EINVAL;
 306
 307         /* Skip Oopes when configured to do so. */
 308         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 309                 return -EINVAL;
 310
 311         /* Explicitly only take the first part of any new crash.
 312          * If our buffer is larger than kmsg_bytes, this can never happen,
 313          * and if our buffer is smaller than kmsg_bytes, we don't want the
 314          * report split across multiple records.
 315          */
 316         if (part != 1)
 317                 return -ENOSPC;
 318
 319         if (!cxt->przs)
 320                 return -ENOSPC;
 321
 322         prz = cxt->przs[cxt->dump_write_cnt];
 323
 324         hlen = ramoops_write_kmsg_hdr(prz, compressed);
 325         if (size + hlen > prz->buffer_size)
 326                 size = prz->buffer_size - hlen;
 327         persistent_ram_write(prz, buf, size);
 328
 329         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 330
 331         return 0;
 332 }
 333
 334 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 335                                 struct timespec time, struct pstore_info *psi)
 336 {
 337         struct ramoops_context *cxt = psi->data;
 338         struct persistent_ram_zone *prz;
 339
 340         switch (type) {
 341         case PSTORE_TYPE_DMESG:
 342                 if (id >= cxt->max_dump_cnt)
 343                         return -EINVAL;
 344                 prz = cxt->przs[id];
 345                 break;
 346         case PSTORE_TYPE_CONSOLE:
 347                 prz = cxt->cprz;
 348                 break;
 349         case PSTORE_TYPE_FTRACE:
 350                 prz = cxt->fprz;
 351                 break;
 352         case PSTORE_TYPE_PMSG:
 353                 prz = cxt->mprz;
 354                 break;
 355         default:
 356                 return -EINVAL;
 357         }
 358
 359         persistent_ram_free_old(prz);
 360         persistent_ram_zap(prz);
 361
 362         return 0;
 363 }
 364
 365 static struct ramoops_context oops_cxt = {
 366         .pstore = {
 367                 .owner  = THIS_MODULE,
 368                 .name   = "ramoops",
 369                 .open   = ramoops_pstore_open,
 370                 .read   = ramoops_pstore_read,
 371                 .write_buf      = ramoops_pstore_write_buf,
 372                 .erase  = ramoops_pstore_erase,
 373         },
 374 };
 375
 376 static void ramoops_free_przs(struct ramoops_context *cxt)
 377 {
 378         int i;
 379
 380         cxt->max_dump_cnt = 0;
 381         if (!cxt->przs)
 382                 return;
 383
 384         for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
 385                 persistent_ram_free(cxt->przs[i]);
 386         kfree(cxt->przs);
 387 }
 388
 389 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
 390                              phys_addr_t *paddr, size_t dump_mem_sz)
 391 {
 392         int err = -ENOMEM;
 393         int i;
 394
 395         if (!cxt->record_size)
 396                 return 0;
 397
 398         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
 399                 dev_err(dev, "no room for dumps\n");
 400                 return -ENOMEM;
 401         }
 402
 403         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
 404         if (!cxt->max_dump_cnt)
 405                 return -ENOMEM;
 406
 407         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
 408                              GFP_KERNEL);
 409         if (!cxt->przs) {
 410                 dev_err(dev, "failed to initialize a prz array for dumps\n");
 411                 goto fail_prz;
 412         }
 413
 414         for (i = 0; i < cxt->max_dump_cnt; i++) {
 415                 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
 416                                                   &cxt->ecc_info,
 417                                                   cxt->memtype);
 418                 if (IS_ERR(cxt->przs[i])) {
 419                         err = PTR_ERR(cxt->przs[i]);
 420                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 421                                 cxt->record_size, (unsigned long long)*paddr, err);
 422                         goto fail_prz;
 423                 }
 424                 *paddr += cxt->record_size;
 425         }
 426
 427         return 0;
 428 fail_prz:
 429         ramoops_free_przs(cxt);
 430         return err;
 431 }
 432
 433 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
 434                             struct persistent_ram_zone **prz,
 435                             phys_addr_t *paddr, size_t sz, u32 sig)
 436 {
 437         if (!sz)
 438                 return 0;
 439
 440         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 441                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 442                         sz, (unsigned long long)*paddr,
 443                         cxt->size, (unsigned long long)cxt->phys_addr);
 444                 return -ENOMEM;
 445         }
 446
 447         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
 448         if (IS_ERR(*prz)) {
 449                 int err = PTR_ERR(*prz);
 450
 451                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 452                         sz, (unsigned long long)*paddr, err);
 453                 return err;
 454         }
 455
 456         persistent_ram_zap(*prz);
 457
 458         *paddr += sz;
 459
 460         return 0;
 461 }
 462
 463 static int ramoops_parse_dt_size(struct platform_device *pdev,
 464                                  const char *propname, u32 *value)
 465 {
 466         u32 val32 = 0;
 467         int ret;
 468
 469         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 470         if (ret < 0 && ret != -EINVAL) {
 471                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 472                         propname, ret);
 473                 return ret;
 474         }
 475
 476         if (val32 > INT_MAX) {
 477                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 478                 return -EOVERFLOW;
 479         }
 480
 481         *value = val32;
 482         return 0;
 483 }
 484
 485 static int ramoops_parse_dt(struct platform_device *pdev,
 486                             struct ramoops_platform_data *pdata)
 487 {
 488         struct device_node *of_node = pdev->dev.of_node;
 489         struct resource *res;
 490         u32 value;
 491         int ret;
 492
 493         dev_dbg(&pdev->dev, "using Device Tree\n");
 494
 495         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 496         if (!res) {
 497                 dev_err(&pdev->dev,
 498                         "failed to locate DT /reserved-memory resource\n");
 499                 return -EINVAL;
 500         }
 501
 502         pdata->mem_size = resource_size(res);
 503         pdata->mem_address = res->start;
 504         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 505         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 506
 507 #define parse_size(name, field) {                                       \
 508                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 509                 if (ret < 0)                                            \
 510                         return ret;                                     \
 511                 field = value;                                          \
 512         }
 513
 514         parse_size("record-size", pdata->record_size);
 515         parse_size("console-size", pdata->console_size);
 516         parse_size("ftrace-size", pdata->ftrace_size);
 517         parse_size("pmsg-size", pdata->pmsg_size);
 518         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 519
 520 #undef parse_size
 521
 522         return 0;
 523 }
 524
 525 static int ramoops_probe(struct platform_device *pdev)
 526 {
 527         struct device *dev = &pdev->dev;
 528         struct ramoops_platform_data *pdata = dev->platform_data;
 529         struct ramoops_context *cxt = &oops_cxt;
 530         size_t dump_mem_sz;
 531         phys_addr_t paddr;
 532         int err = -EINVAL;
 533
 534         if (dev_of_node(dev) && !pdata) {
 535                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 536                 if (!pdata) {
 537                         err = -ENOMEM;
 538                         goto fail_out;
 539                 }
 540
 541                 err = ramoops_parse_dt(pdev, pdata);
 542                 if (err < 0)
 543                         goto fail_out;
 544         }
 545
 546         /* Only a single ramoops area allowed at a time, so fail extra
 547          * probes.
 548          */
 549         if (cxt->max_dump_cnt)
 550                 goto fail_out;
 551
 552         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 553                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 554                 pr_err("The memory size and the record/console size must be "
 555                         "non-zero\n");
 556                 goto fail_out;
 557         }
 558
 559         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 560                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 561         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 562                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 563         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 564                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 565         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 566                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 567
 568         cxt->size = pdata->mem_size;
 569         cxt->phys_addr = pdata->mem_address;
 570         cxt->memtype = pdata->mem_type;
 571         cxt->record_size = pdata->record_size;
 572         cxt->console_size = pdata->console_size;
 573         cxt->ftrace_size = pdata->ftrace_size;
 574         cxt->pmsg_size = pdata->pmsg_size;
 575         cxt->dump_oops = pdata->dump_oops;
 576         cxt->ecc_info = pdata->ecc_info;
 577
 578         paddr = cxt->phys_addr;
 579
 580         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 581                         - cxt->pmsg_size;
 582         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 583         if (err)
 584                 goto fail_out;
 585
 586         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 587                                cxt->console_size, 0);
 588         if (err)
 589                 goto fail_init_cprz;
 590
 591         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 592                                LINUX_VERSION_CODE);
 593         if (err)
 594                 goto fail_init_fprz;
 595
 596         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
 597         if (err)
 598                 goto fail_init_mprz;
 599
 600         cxt->pstore.data = cxt;
 601         /*
 602          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 603          * have to handle dumps, we must have at least record_size buffer. And
 604          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 605          * ZERO_SIZE_PTR).
 606          */
 607         if (cxt->console_size)
 608                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 609         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 610         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 611         spin_lock_init(&cxt->pstore.buf_lock);
 612         if (!cxt->pstore.buf) {
 613                 pr_err("cannot allocate pstore buffer\n");
 614                 err = -ENOMEM;
 615                 goto fail_clear;
 616         }
 617
 618         err = pstore_register(&cxt->pstore);
 619         if (err) {
 620                 pr_err("registering with pstore failed\n");
 621                 goto fail_buf;
 622         }
 623
 624         /*
 625          * Update the module parameter variables as well so they are visible
 626          * through /sys/module/ramoops/parameters/
 627          */
 628         mem_size = pdata->mem_size;
 629         mem_address = pdata->mem_address;
 630         record_size = pdata->record_size;
 631         dump_oops = pdata->dump_oops;
 632         ramoops_console_size = pdata->console_size;
 633         ramoops_pmsg_size = pdata->pmsg_size;
 634         ramoops_ftrace_size = pdata->ftrace_size;
 635
 636         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 637                 cxt->size, (unsigned long long)cxt->phys_addr,
 638                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 639
 640         return 0;
 641
 642 fail_buf:
 643         kfree(cxt->pstore.buf);
 644 fail_clear:
 645         cxt->pstore.bufsize = 0;
 646         persistent_ram_free(cxt->mprz);
 647 fail_init_mprz:
 648         persistent_ram_free(cxt->fprz);
 649 fail_init_fprz:
 650         persistent_ram_free(cxt->cprz);
 651 fail_init_cprz:
 652         ramoops_free_przs(cxt);
 653 fail_out:
 654         return err;
 655 }
 656
 657 static int ramoops_remove(struct platform_device *pdev)
 658 {
 659         struct ramoops_context *cxt = &oops_cxt;
 660
 661         pstore_unregister(&cxt->pstore);
 662         cxt->max_dump_cnt = 0;
 663
 664         kfree(cxt->pstore.buf);
 665         cxt->pstore.bufsize = 0;
 666
 667         persistent_ram_free(cxt->mprz);
 668         persistent_ram_free(cxt->fprz);
 669         persistent_ram_free(cxt->cprz);
 670         ramoops_free_przs(cxt);
 671
 672         return 0;
 673 }
 674
 675 static const struct of_device_id dt_match[] = {
 676         { .compatible = "ramoops" },
 677         {}
 678 };
 679
 680 static struct platform_driver ramoops_driver = {
 681         .probe          = ramoops_probe,
 682         .remove         = ramoops_remove,
 683         .driver         = {
 684                 .name           = "ramoops",
 685                 .of_match_table = dt_match,
 686         },
 687 };
 688
 689 static void ramoops_register_dummy(void)
 690 {
 691         if (!mem_size)
 692                 return;
 693
 694         pr_info("using module parameters\n");
 695
 696         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 697         if (!dummy_data) {
 698                 pr_info("could not allocate pdata\n");
 699                 return;
 700         }
 701
 702         dummy_data->mem_size = mem_size;
 703         dummy_data->mem_address = mem_address;
 704         dummy_data->mem_type = mem_type;
 705         dummy_data->record_size = record_size;
 706         dummy_data->console_size = ramoops_console_size;
 707         dummy_data->ftrace_size = ramoops_ftrace_size;
 708         dummy_data->pmsg_size = ramoops_pmsg_size;
 709         dummy_data->dump_oops = dump_oops;
 710         /*
 711          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 712          * (using 1 byte for ECC isn't much of use anyway).
 713          */
 714         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 715
 716         dummy = platform_device_register_data(NULL, "ramoops", -1,
 717                         dummy_data, sizeof(struct ramoops_platform_data));
 718         if (IS_ERR(dummy)) {
 719                 pr_info("could not create platform device: %ld\n",
 720                         PTR_ERR(dummy));
 721         }
 722 }
 723
 724 static int __init ramoops_init(void)
 725 {
 726         ramoops_register_dummy();
 727         return platform_driver_register(&ramoops_driver);
 728 }
 729 postcore_initcall(ramoops_init);
 730
 731 static void __exit ramoops_exit(void)
 732 {
 733         platform_driver_unregister(&ramoops_driver);
 734         platform_device_unregister(dummy);
 735         kfree(dummy_data);
 736 }
 737 module_exit(ramoops_exit);
 738
 739 MODULE_LICENSE("GPL");
 740 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 741 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");