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 notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
 335                                                  enum kmsg_dump_reason reason,
 336                                                  u64 *id, unsigned int part,
 337                                                  const char __user *buf,
 338                                                  bool compressed, size_t size,
 339                                                  struct pstore_info *psi)
 340 {
 341         if (type == PSTORE_TYPE_PMSG) {
 342                 struct ramoops_context *cxt = psi->data;
 343
 344                 if (!cxt->mprz)
 345                         return -ENOMEM;
 346                 return persistent_ram_write_user(cxt->mprz, buf, size);
 347         }
 348
 349         return -EINVAL;
 350 }
 351
 352 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 353                                 struct timespec time, struct pstore_info *psi)
 354 {
 355         struct ramoops_context *cxt = psi->data;
 356         struct persistent_ram_zone *prz;
 357
 358         switch (type) {
 359         case PSTORE_TYPE_DMESG:
 360                 if (id >= cxt->max_dump_cnt)
 361                         return -EINVAL;
 362                 prz = cxt->przs[id];
 363                 break;
 364         case PSTORE_TYPE_CONSOLE:
 365                 prz = cxt->cprz;
 366                 break;
 367         case PSTORE_TYPE_FTRACE:
 368                 prz = cxt->fprz;
 369                 break;
 370         case PSTORE_TYPE_PMSG:
 371                 prz = cxt->mprz;
 372                 break;
 373         default:
 374                 return -EINVAL;
 375         }
 376
 377         persistent_ram_free_old(prz);
 378         persistent_ram_zap(prz);
 379
 380         return 0;
 381 }
 382
 383 static struct ramoops_context oops_cxt = {
 384         .pstore = {
 385                 .owner  = THIS_MODULE,
 386                 .name   = "ramoops",
 387                 .open   = ramoops_pstore_open,
 388                 .read   = ramoops_pstore_read,
 389                 .write_buf      = ramoops_pstore_write_buf,
 390                 .write_buf_user = ramoops_pstore_write_buf_user,
 391                 .erase  = ramoops_pstore_erase,
 392         },
 393 };
 394
 395 static void ramoops_free_przs(struct ramoops_context *cxt)
 396 {
 397         int i;
 398
 399         if (!cxt->przs)
 400                 return;
 401
 402         for (i = 0; i < cxt->max_dump_cnt; i++)
 403                 persistent_ram_free(cxt->przs[i]);
 404
 405         kfree(cxt->przs);
 406         cxt->max_dump_cnt = 0;
 407 }
 408
 409 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
 410                              phys_addr_t *paddr, size_t dump_mem_sz)
 411 {
 412         int err = -ENOMEM;
 413         int i;
 414
 415         if (!cxt->record_size)
 416                 return 0;
 417
 418         if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
 419                 dev_err(dev, "no room for dumps\n");
 420                 return -ENOMEM;
 421         }
 422
 423         cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
 424         if (!cxt->max_dump_cnt)
 425                 return -ENOMEM;
 426
 427         cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
 428                              GFP_KERNEL);
 429         if (!cxt->przs) {
 430                 dev_err(dev, "failed to initialize a prz array for dumps\n");
 431                 goto fail_mem;
 432         }
 433
 434         for (i = 0; i < cxt->max_dump_cnt; i++) {
 435                 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
 436                                                   &cxt->ecc_info,
 437                                                   cxt->memtype);
 438                 if (IS_ERR(cxt->przs[i])) {
 439                         err = PTR_ERR(cxt->przs[i]);
 440                         dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 441                                 cxt->record_size, (unsigned long long)*paddr, err);
 442
 443                         while (i > 0) {
 444                                 i--;
 445                                 persistent_ram_free(cxt->przs[i]);
 446                         }
 447                         goto fail_prz;
 448                 }
 449                 *paddr += cxt->record_size;
 450         }
 451
 452         return 0;
 453 fail_prz:
 454         kfree(cxt->przs);
 455 fail_mem:
 456         cxt->max_dump_cnt = 0;
 457         return err;
 458 }
 459
 460 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
 461                             struct persistent_ram_zone **prz,
 462                             phys_addr_t *paddr, size_t sz, u32 sig)
 463 {
 464         if (!sz)
 465                 return 0;
 466
 467         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 468                 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 469                         sz, (unsigned long long)*paddr,
 470                         cxt->size, (unsigned long long)cxt->phys_addr);
 471                 return -ENOMEM;
 472         }
 473
 474         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
 475         if (IS_ERR(*prz)) {
 476                 int err = PTR_ERR(*prz);
 477
 478                 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
 479                         sz, (unsigned long long)*paddr, err);
 480                 return err;
 481         }
 482
 483         persistent_ram_zap(*prz);
 484
 485         *paddr += sz;
 486
 487         return 0;
 488 }
 489
 490 static int ramoops_parse_dt_size(struct platform_device *pdev,
 491                                  const char *propname, u32 *value)
 492 {
 493         u32 val32 = 0;
 494         int ret;
 495
 496         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 497         if (ret < 0 && ret != -EINVAL) {
 498                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 499                         propname, ret);
 500                 return ret;
 501         }
 502
 503         if (val32 > INT_MAX) {
 504                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 505                 return -EOVERFLOW;
 506         }
 507
 508         *value = val32;
 509         return 0;
 510 }
 511
 512 static int ramoops_parse_dt(struct platform_device *pdev,
 513                             struct ramoops_platform_data *pdata)
 514 {
 515         struct device_node *of_node = pdev->dev.of_node;
 516         struct resource *res;
 517         u32 value;
 518         int ret;
 519
 520         dev_dbg(&pdev->dev, "using Device Tree\n");
 521
 522         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 523         if (!res) {
 524                 dev_err(&pdev->dev,
 525                         "failed to locate DT /reserved-memory resource\n");
 526                 return -EINVAL;
 527         }
 528
 529         pdata->mem_size = resource_size(res);
 530         pdata->mem_address = res->start;
 531         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 532         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 533
 534 #define parse_size(name, field) {                                       \
 535                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 536                 if (ret < 0)                                            \
 537                         return ret;                                     \
 538                 field = value;                                          \
 539         }
 540
 541         parse_size("record-size", pdata->record_size);
 542         parse_size("console-size", pdata->console_size);
 543         parse_size("ftrace-size", pdata->ftrace_size);
 544         parse_size("pmsg-size", pdata->pmsg_size);
 545         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 546
 547 #undef parse_size
 548
 549         return 0;
 550 }
 551
 552 static int ramoops_probe(struct platform_device *pdev)
 553 {
 554         struct device *dev = &pdev->dev;
 555         struct ramoops_platform_data *pdata = dev->platform_data;
 556         struct ramoops_context *cxt = &oops_cxt;
 557         size_t dump_mem_sz;
 558         phys_addr_t paddr;
 559         int err = -EINVAL;
 560
 561         if (dev_of_node(dev) && !pdata) {
 562                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 563                 if (!pdata) {
 564                         err = -ENOMEM;
 565                         goto fail_out;
 566                 }
 567
 568                 err = ramoops_parse_dt(pdev, pdata);
 569                 if (err < 0)
 570                         goto fail_out;
 571         }
 572
 573         /* Only a single ramoops area allowed at a time, so fail extra
 574          * probes.
 575          */
 576         if (cxt->max_dump_cnt)
 577                 goto fail_out;
 578
 579         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 580                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 581                 pr_err("The memory size and the record/console size must be "
 582                         "non-zero\n");
 583                 goto fail_out;
 584         }
 585
 586         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 587                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 588         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 589                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 590         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 591                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 592         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 593                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 594
 595         cxt->size = pdata->mem_size;
 596         cxt->phys_addr = pdata->mem_address;
 597         cxt->memtype = pdata->mem_type;
 598         cxt->record_size = pdata->record_size;
 599         cxt->console_size = pdata->console_size;
 600         cxt->ftrace_size = pdata->ftrace_size;
 601         cxt->pmsg_size = pdata->pmsg_size;
 602         cxt->dump_oops = pdata->dump_oops;
 603         cxt->ecc_info = pdata->ecc_info;
 604
 605         paddr = cxt->phys_addr;
 606
 607         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 608                         - cxt->pmsg_size;
 609         err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
 610         if (err)
 611                 goto fail_out;
 612
 613         err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
 614                                cxt->console_size, 0);
 615         if (err)
 616                 goto fail_init_cprz;
 617
 618         err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
 619                                LINUX_VERSION_CODE);
 620         if (err)
 621                 goto fail_init_fprz;
 622
 623         err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
 624         if (err)
 625                 goto fail_init_mprz;
 626
 627         cxt->pstore.data = cxt;
 628         /*
 629          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 630          * have to handle dumps, we must have at least record_size buffer. And
 631          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 632          * ZERO_SIZE_PTR).
 633          */
 634         if (cxt->console_size)
 635                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 636         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 637         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 638         if (!cxt->pstore.buf) {
 639                 pr_err("cannot allocate pstore buffer\n");
 640                 err = -ENOMEM;
 641                 goto fail_clear;
 642         }
 643         spin_lock_init(&cxt->pstore.buf_lock);
 644
 645         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 646         if (cxt->console_size)
 647                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 648         if (cxt->ftrace_size)
 649                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 650         if (cxt->pmsg_size)
 651                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 652
 653         err = pstore_register(&cxt->pstore);
 654         if (err) {
 655                 pr_err("registering with pstore failed\n");
 656                 goto fail_buf;
 657         }
 658
 659         /*
 660          * Update the module parameter variables as well so they are visible
 661          * through /sys/module/ramoops/parameters/
 662          */
 663         mem_size = pdata->mem_size;
 664         mem_address = pdata->mem_address;
 665         record_size = pdata->record_size;
 666         dump_oops = pdata->dump_oops;
 667         ramoops_console_size = pdata->console_size;
 668         ramoops_pmsg_size = pdata->pmsg_size;
 669         ramoops_ftrace_size = pdata->ftrace_size;
 670
 671         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 672                 cxt->size, (unsigned long long)cxt->phys_addr,
 673                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 674
 675         return 0;
 676
 677 fail_buf:
 678         kfree(cxt->pstore.buf);
 679 fail_clear:
 680         cxt->pstore.bufsize = 0;
 681         persistent_ram_free(cxt->mprz);
 682 fail_init_mprz:
 683         persistent_ram_free(cxt->fprz);
 684 fail_init_fprz:
 685         persistent_ram_free(cxt->cprz);
 686 fail_init_cprz:
 687         ramoops_free_przs(cxt);
 688 fail_out:
 689         return err;
 690 }
 691
 692 static int ramoops_remove(struct platform_device *pdev)
 693 {
 694         struct ramoops_context *cxt = &oops_cxt;
 695
 696         pstore_unregister(&cxt->pstore);
 697
 698         kfree(cxt->pstore.buf);
 699         cxt->pstore.bufsize = 0;
 700
 701         persistent_ram_free(cxt->mprz);
 702         persistent_ram_free(cxt->fprz);
 703         persistent_ram_free(cxt->cprz);
 704         ramoops_free_przs(cxt);
 705
 706         return 0;
 707 }
 708
 709 static const struct of_device_id dt_match[] = {
 710         { .compatible = "ramoops" },
 711         {}
 712 };
 713
 714 static struct platform_driver ramoops_driver = {
 715         .probe          = ramoops_probe,
 716         .remove         = ramoops_remove,
 717         .driver         = {
 718                 .name           = "ramoops",
 719                 .of_match_table = dt_match,
 720         },
 721 };
 722
 723 static void ramoops_register_dummy(void)
 724 {
 725         if (!mem_size)
 726                 return;
 727
 728         pr_info("using module parameters\n");
 729
 730         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 731         if (!dummy_data) {
 732                 pr_info("could not allocate pdata\n");
 733                 return;
 734         }
 735
 736         dummy_data->mem_size = mem_size;
 737         dummy_data->mem_address = mem_address;
 738         dummy_data->mem_type = mem_type;
 739         dummy_data->record_size = record_size;
 740         dummy_data->console_size = ramoops_console_size;
 741         dummy_data->ftrace_size = ramoops_ftrace_size;
 742         dummy_data->pmsg_size = ramoops_pmsg_size;
 743         dummy_data->dump_oops = dump_oops;
 744         /*
 745          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 746          * (using 1 byte for ECC isn't much of use anyway).
 747          */
 748         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 749
 750         dummy = platform_device_register_data(NULL, "ramoops", -1,
 751                         dummy_data, sizeof(struct ramoops_platform_data));
 752         if (IS_ERR(dummy)) {
 753                 pr_info("could not create platform device: %ld\n",
 754                         PTR_ERR(dummy));
 755         }
 756 }
 757
 758 static int __init ramoops_init(void)
 759 {
 760         ramoops_register_dummy();
 761         return platform_driver_register(&ramoops_driver);
 762 }
 763 postcore_initcall(ramoops_init);
 764
 765 static void __exit ramoops_exit(void)
 766 {
 767         platform_driver_unregister(&ramoops_driver);
 768         platform_device_unregister(dummy);
 769         kfree(dummy_data);
 770 }
 771 module_exit(ramoops_exit);
 772
 773 MODULE_LICENSE("GPL");
 774 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 775 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");