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 **dprzs;     /* Oops dump zones */
  89         struct persistent_ram_zone *cprz;       /* Console zone */
  90         struct persistent_ram_zone **fprzs;     /* Ftrace zones */
  91         struct persistent_ram_zone *mprz;       /* PMSG zone */
  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         u32 flags;
 101         struct persistent_ram_ecc_info ecc_info;
 102         unsigned int max_dump_cnt;
 103         unsigned int dump_write_cnt;
 104         /* _read_cnt need clear on ramoops_pstore_open */
 105         unsigned int dump_read_cnt;
 106         unsigned int console_read_cnt;
 107         unsigned int max_ftrace_cnt;
 108         unsigned int ftrace_read_cnt;
 109         unsigned int pmsg_read_cnt;
 110         struct pstore_info pstore;
 111 };
 112
 113 static struct platform_device *dummy;
 114 static struct ramoops_platform_data *dummy_data;
 115
 116 static int ramoops_pstore_open(struct pstore_info *psi)
 117 {
 118         struct ramoops_context *cxt = psi->data;
 119
 120         cxt->dump_read_cnt = 0;
 121         cxt->console_read_cnt = 0;
 122         cxt->ftrace_read_cnt = 0;
 123         cxt->pmsg_read_cnt = 0;
 124         return 0;
 125 }
 126
 127 static struct persistent_ram_zone *
 128 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 129                      u64 *id,
 130                      enum pstore_type_id *typep, enum pstore_type_id type,
 131                      bool update)
 132 {
 133         struct persistent_ram_zone *prz;
 134         int i = (*c)++;
 135
 136         if (i >= max)
 137                 return NULL;
 138
 139         prz = przs[i];
 140         if (!prz)
 141                 return NULL;
 142
 143         /* Update old/shadowed buffer. */
 144         if (update)
 145                 persistent_ram_save_old(prz);
 146
 147         if (!persistent_ram_old_size(prz))
 148                 return NULL;
 149
 150         *typep = type;
 151         *id = i;
 152
 153         return prz;
 154 }
 155
 156 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 157                                   bool *compressed)
 158 {
 159         char data_type;
 160         int header_length = 0;
 161
 162         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 163                         &time->tv_nsec, &data_type, &header_length) == 3) {
 164                 if (data_type == 'C')
 165                         *compressed = true;
 166                 else
 167                         *compressed = false;
 168         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 169                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
 170                         *compressed = false;
 171         } else {
 172                 time->tv_sec = 0;
 173                 time->tv_nsec = 0;
 174                 *compressed = false;
 175         }
 176         return header_length;
 177 }
 178
 179 static bool prz_ok(struct persistent_ram_zone *prz)
 180 {
 181         return !!prz && !!(persistent_ram_old_size(prz) +
 182                            persistent_ram_ecc_string(prz, NULL, 0));
 183 }
 184
 185 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 186                                   struct persistent_ram_zone *src)
 187 {
 188         size_t dest_size, src_size, total, dest_off, src_off;
 189         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 190         void *merged_buf;
 191         struct pstore_ftrace_record *drec, *srec, *mrec;
 192         size_t record_size = sizeof(struct pstore_ftrace_record);
 193
 194         dest_off = dest->old_log_size % record_size;
 195         dest_size = dest->old_log_size - dest_off;
 196
 197         src_off = src->old_log_size % record_size;
 198         src_size = src->old_log_size - src_off;
 199
 200         total = dest_size + src_size;
 201         merged_buf = kmalloc(total, GFP_KERNEL);
 202         if (!merged_buf)
 203                 return -ENOMEM;
 204
 205         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 206         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 207         mrec = (struct pstore_ftrace_record *)(merged_buf);
 208
 209         while (dest_size > 0 && src_size > 0) {
 210                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 211                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 212                         mrec[merged_idx++] = drec[dest_idx++];
 213                         dest_size -= record_size;
 214                 } else {
 215                         mrec[merged_idx++] = srec[src_idx++];
 216                         src_size -= record_size;
 217                 }
 218         }
 219
 220         while (dest_size > 0) {
 221                 mrec[merged_idx++] = drec[dest_idx++];
 222                 dest_size -= record_size;
 223         }
 224
 225         while (src_size > 0) {
 226                 mrec[merged_idx++] = srec[src_idx++];
 227                 src_size -= record_size;
 228         }
 229
 230         kfree(dest->old_log);
 231         dest->old_log = merged_buf;
 232         dest->old_log_size = total;
 233
 234         return 0;
 235 }
 236
 237 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
 238                                    int *count, struct timespec *time,
 239                                    char **buf, bool *compressed,
 240                                    ssize_t *ecc_notice_size,
 241                                    struct pstore_info *psi)
 242 {
 243         ssize_t size = 0;
 244         struct ramoops_context *cxt = psi->data;
 245         struct persistent_ram_zone *prz = NULL;
 246         int header_length = 0;
 247         bool free_prz = false;
 248
 249         /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 250          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 251          * valid time stamps, so it is initialized to zero.
 252          */
 253         time->tv_sec = 0;
 254         time->tv_nsec = 0;
 255         *compressed = false;
 256
 257         /* Find the next valid persistent_ram_zone for DMESG */
 258         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 259                 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
 260                                            cxt->max_dump_cnt, id, type,
 261                                            PSTORE_TYPE_DMESG, 1);
 262                 if (!prz_ok(prz))
 263                         continue;
 264                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 265                                                       time, compressed);
 266                 /* Clear and skip this DMESG record if it has no valid header */
 267                 if (!header_length) {
 268                         persistent_ram_free_old(prz);
 269                         persistent_ram_zap(prz);
 270                         prz = NULL;
 271                 }
 272         }
 273
 274         if (!prz_ok(prz))
 275                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 276                                            1, id, type, PSTORE_TYPE_CONSOLE, 0);
 277
 278         if (!prz_ok(prz))
 279                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 280                                            1, id, type, PSTORE_TYPE_PMSG, 0);
 281
 282         /* ftrace is last since it may want to dynamically allocate memory. */
 283         if (!prz_ok(prz) && cxt->fprzs) {
 284                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
 285                         prz = ramoops_get_next_prz(cxt->fprzs,
 286                                         &cxt->ftrace_read_cnt, 1, id, type,
 287                                         PSTORE_TYPE_FTRACE, 0);
 288                 } else {
 289                         /*
 290                          * Build a new dummy record which combines all the
 291                          * per-cpu records including metadata and ecc info.
 292                          */
 293                         struct persistent_ram_zone *tmp_prz, *prz_next;
 294
 295                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 296                                           GFP_KERNEL);
 297                         if (!tmp_prz)
 298                                 return -ENOMEM;
 299                         free_prz = true;
 300
 301                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 302                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 303                                                 &cxt->ftrace_read_cnt,
 304                                                 cxt->max_ftrace_cnt, id,
 305                                                 type, PSTORE_TYPE_FTRACE, 0);
 306
 307                                 if (!prz_ok(prz_next))
 308                                         continue;
 309
 310                                 tmp_prz->ecc_info = prz_next->ecc_info;
 311                                 tmp_prz->corrected_bytes +=
 312                                                 prz_next->corrected_bytes;
 313                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 314                                 size = ftrace_log_combine(tmp_prz, prz_next);
 315                                 if (size)
 316                                         goto out;
 317                         }
 318                         *id = 0;
 319                         prz = tmp_prz;
 320                 }
 321         }
 322
 323         if (!prz_ok(prz)) {
 324                 size = 0;
 325                 goto out;
 326         }
 327
 328         size = persistent_ram_old_size(prz) - header_length;
 329
 330         /* ECC correction notice */
 331         *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 332
 333         *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
 334         if (*buf == NULL) {
 335                 size = -ENOMEM;
 336                 goto out;
 337         }
 338
 339         memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
 340
 341         persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
 342
 343 out:
 344         if (free_prz) {
 345                 kfree(prz->old_log);
 346                 kfree(prz);
 347         }
 348
 349         return size;
 350 }
 351
 352 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 353                                      bool compressed)
 354 {
 355         char *hdr;
 356         struct timespec timestamp;
 357         size_t len;
 358
 359         /* Report zeroed timestamp if called before timekeeping has resumed. */
 360         if (__getnstimeofday(&timestamp)) {
 361                 timestamp.tv_sec = 0;
 362                 timestamp.tv_nsec = 0;
 363         }
 364         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 365                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
 366                 compressed ? 'C' : 'D');
 367         WARN_ON_ONCE(!hdr);
 368         len = hdr ? strlen(hdr) : 0;
 369         persistent_ram_write(prz, hdr, len);
 370         kfree(hdr);
 371
 372         return len;
 373 }
 374
 375 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
 376                                             enum kmsg_dump_reason reason,
 377                                             u64 *id, unsigned int part,
 378                                             const char *buf,
 379                                             bool compressed, size_t size,
 380                                             struct pstore_info *psi)
 381 {
 382         struct ramoops_context *cxt = psi->data;
 383         struct persistent_ram_zone *prz;
 384         size_t hlen;
 385
 386         if (type == PSTORE_TYPE_CONSOLE) {
 387                 if (!cxt->cprz)
 388                         return -ENOMEM;
 389                 persistent_ram_write(cxt->cprz, buf, size);
 390                 return 0;
 391         } else if (type == PSTORE_TYPE_FTRACE) {
 392                 int zonenum;
 393
 394                 if (!cxt->fprzs)
 395                         return -ENOMEM;
 396                 /*
 397                  * Choose zone by if we're using per-cpu buffers.
 398                  */
 399                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 400                         zonenum = smp_processor_id();
 401                 else
 402                         zonenum = 0;
 403
 404                 persistent_ram_write(cxt->fprzs[zonenum], buf, size);
 405                 return 0;
 406         } else if (type == PSTORE_TYPE_PMSG) {
 407                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 408                 return -EINVAL;
 409         }
 410
 411         if (type != PSTORE_TYPE_DMESG)
 412                 return -EINVAL;
 413
 414         /* Out of the various dmesg dump types, ramoops is currently designed
 415          * to only store crash logs, rather than storing general kernel logs.
 416          */
 417         if (reason != KMSG_DUMP_OOPS &&
 418             reason != KMSG_DUMP_PANIC)
 419                 return -EINVAL;
 420
 421         /* Skip Oopes when configured to do so. */
 422         if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 423                 return -EINVAL;
 424
 425         /* Explicitly only take the first part of any new crash.
 426          * If our buffer is larger than kmsg_bytes, this can never happen,
 427          * and if our buffer is smaller than kmsg_bytes, we don't want the
 428          * report split across multiple records.
 429          */
 430         if (part != 1)
 431                 return -ENOSPC;
 432
 433         if (!cxt->dprzs)
 434                 return -ENOSPC;
 435
 436         prz = cxt->dprzs[cxt->dump_write_cnt];
 437
 438         hlen = ramoops_write_kmsg_hdr(prz, compressed);
 439         if (size + hlen > prz->buffer_size)
 440                 size = prz->buffer_size - hlen;
 441         persistent_ram_write(prz, buf, size);
 442
 443         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 444
 445         return 0;
 446 }
 447
 448 static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
 449                                                  enum kmsg_dump_reason reason,
 450                                                  u64 *id, unsigned int part,
 451                                                  const char __user *buf,
 452                                                  bool compressed, size_t size,
 453                                                  struct pstore_info *psi)
 454 {
 455         if (type == PSTORE_TYPE_PMSG) {
 456                 struct ramoops_context *cxt = psi->data;
 457
 458                 if (!cxt->mprz)
 459                         return -ENOMEM;
 460                 return persistent_ram_write_user(cxt->mprz, buf, size);
 461         }
 462
 463         return -EINVAL;
 464 }
 465
 466 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
 467                                 struct timespec time, struct pstore_info *psi)
 468 {
 469         struct ramoops_context *cxt = psi->data;
 470         struct persistent_ram_zone *prz;
 471
 472         switch (type) {
 473         case PSTORE_TYPE_DMESG:
 474                 if (id >= cxt->max_dump_cnt)
 475                         return -EINVAL;
 476                 prz = cxt->dprzs[id];
 477                 break;
 478         case PSTORE_TYPE_CONSOLE:
 479                 prz = cxt->cprz;
 480                 break;
 481         case PSTORE_TYPE_FTRACE:
 482                 if (id >= cxt->max_ftrace_cnt)
 483                         return -EINVAL;
 484                 prz = cxt->fprzs[id];
 485                 break;
 486         case PSTORE_TYPE_PMSG:
 487                 prz = cxt->mprz;
 488                 break;
 489         default:
 490                 return -EINVAL;
 491         }
 492
 493         persistent_ram_free_old(prz);
 494         persistent_ram_zap(prz);
 495
 496         return 0;
 497 }
 498
 499 static struct ramoops_context oops_cxt = {
 500         .pstore = {
 501                 .owner  = THIS_MODULE,
 502                 .name   = "ramoops",
 503                 .open   = ramoops_pstore_open,
 504                 .read   = ramoops_pstore_read,
 505                 .write_buf      = ramoops_pstore_write_buf,
 506                 .write_buf_user = ramoops_pstore_write_buf_user,
 507                 .erase  = ramoops_pstore_erase,
 508         },
 509 };
 510
 511 static void ramoops_free_przs(struct ramoops_context *cxt)
 512 {
 513         int i;
 514
 515         /* Free dump PRZs */
 516         if (cxt->dprzs) {
 517                 for (i = 0; i < cxt->max_dump_cnt; i++)
 518                         persistent_ram_free(cxt->dprzs[i]);
 519
 520                 kfree(cxt->dprzs);
 521                 cxt->max_dump_cnt = 0;
 522         }
 523
 524         /* Free ftrace PRZs */
 525         if (cxt->fprzs) {
 526                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 527                         persistent_ram_free(cxt->fprzs[i]);
 528                 kfree(cxt->fprzs);
 529                 cxt->max_ftrace_cnt = 0;
 530         }
 531 }
 532
 533 static int ramoops_init_przs(const char *name,
 534                              struct device *dev, struct ramoops_context *cxt,
 535                              struct persistent_ram_zone ***przs,
 536                              phys_addr_t *paddr, size_t mem_sz,
 537                              ssize_t record_size,
 538                              unsigned int *cnt, u32 sig, u32 flags)
 539 {
 540         int err = -ENOMEM;
 541         int i;
 542         size_t zone_sz;
 543         struct persistent_ram_zone **prz_ar;
 544
 545         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 546         if (mem_sz == 0 || record_size == 0) {
 547                 *cnt = 0;
 548                 return 0;
 549         }
 550
 551         /*
 552          * If we have a negative record size, calculate it based on
 553          * mem_sz / *cnt. If we have a positive record size, calculate
 554          * cnt from mem_sz / record_size.
 555          */
 556         if (record_size < 0) {
 557                 if (*cnt == 0)
 558                         return 0;
 559                 record_size = mem_sz / *cnt;
 560                 if (record_size == 0) {
 561                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 562                                 name, mem_sz, *cnt);
 563                         goto fail;
 564                 }
 565         } else {
 566                 *cnt = mem_sz / record_size;
 567                 if (*cnt == 0) {
 568                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 569                                 name, mem_sz, record_size);
 570                         goto fail;
 571                 }
 572         }
 573
 574         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 575                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 576                         name,
 577                         mem_sz, (unsigned long long)*paddr,
 578                         cxt->size, (unsigned long long)cxt->phys_addr);
 579                 goto fail;
 580         }
 581
 582         zone_sz = mem_sz / *cnt;
 583         if (!zone_sz) {
 584                 dev_err(dev, "%s zone size == 0\n", name);
 585                 goto fail;
 586         }
 587
 588         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 589         if (!prz_ar)
 590                 goto fail;
 591
 592         for (i = 0; i < *cnt; i++) {
 593                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 594                                                   &cxt->ecc_info,
 595                                                   cxt->memtype, flags);
 596                 if (IS_ERR(prz_ar[i])) {
 597                         err = PTR_ERR(prz_ar[i]);
 598                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 599                                 name, record_size,
 600                                 (unsigned long long)*paddr, err);
 601
 602                         while (i > 0) {
 603                                 i--;
 604                                 persistent_ram_free(prz_ar[i]);
 605                         }
 606                         kfree(prz_ar);
 607                         goto fail;
 608                 }
 609                 *paddr += zone_sz;
 610         }
 611
 612         *przs = prz_ar;
 613         return 0;
 614
 615 fail:
 616         *cnt = 0;
 617         return err;
 618 }
 619
 620 static int ramoops_init_prz(const char *name,
 621                             struct device *dev, struct ramoops_context *cxt,
 622                             struct persistent_ram_zone **prz,
 623                             phys_addr_t *paddr, size_t sz, u32 sig)
 624 {
 625         if (!sz)
 626                 return 0;
 627
 628         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 629                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 630                         name, sz, (unsigned long long)*paddr,
 631                         cxt->size, (unsigned long long)cxt->phys_addr);
 632                 return -ENOMEM;
 633         }
 634
 635         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 636                                   cxt->memtype, 0);
 637         if (IS_ERR(*prz)) {
 638                 int err = PTR_ERR(*prz);
 639
 640                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 641                         name, sz, (unsigned long long)*paddr, err);
 642                 return err;
 643         }
 644
 645         persistent_ram_zap(*prz);
 646
 647         *paddr += sz;
 648
 649         return 0;
 650 }
 651
 652 static int ramoops_parse_dt_size(struct platform_device *pdev,
 653                                  const char *propname, u32 *value)
 654 {
 655         u32 val32 = 0;
 656         int ret;
 657
 658         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 659         if (ret < 0 && ret != -EINVAL) {
 660                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 661                         propname, ret);
 662                 return ret;
 663         }
 664
 665         if (val32 > INT_MAX) {
 666                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 667                 return -EOVERFLOW;
 668         }
 669
 670         *value = val32;
 671         return 0;
 672 }
 673
 674 static int ramoops_parse_dt(struct platform_device *pdev,
 675                             struct ramoops_platform_data *pdata)
 676 {
 677         struct device_node *of_node = pdev->dev.of_node;
 678         struct resource *res;
 679         u32 value;
 680         int ret;
 681
 682         dev_dbg(&pdev->dev, "using Device Tree\n");
 683
 684         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 685         if (!res) {
 686                 dev_err(&pdev->dev,
 687                         "failed to locate DT /reserved-memory resource\n");
 688                 return -EINVAL;
 689         }
 690
 691         pdata->mem_size = resource_size(res);
 692         pdata->mem_address = res->start;
 693         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 694         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 695
 696 #define parse_size(name, field) {                                       \
 697                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 698                 if (ret < 0)                                            \
 699                         return ret;                                     \
 700                 field = value;                                          \
 701         }
 702
 703         parse_size("record-size", pdata->record_size);
 704         parse_size("console-size", pdata->console_size);
 705         parse_size("ftrace-size", pdata->ftrace_size);
 706         parse_size("pmsg-size", pdata->pmsg_size);
 707         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 708         parse_size("flags", pdata->flags);
 709
 710 #undef parse_size
 711
 712         return 0;
 713 }
 714
 715 static int ramoops_probe(struct platform_device *pdev)
 716 {
 717         struct device *dev = &pdev->dev;
 718         struct ramoops_platform_data *pdata = dev->platform_data;
 719         struct ramoops_context *cxt = &oops_cxt;
 720         size_t dump_mem_sz;
 721         phys_addr_t paddr;
 722         int err = -EINVAL;
 723
 724         if (dev_of_node(dev) && !pdata) {
 725                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 726                 if (!pdata) {
 727                         pr_err("cannot allocate platform data buffer\n");
 728                         err = -ENOMEM;
 729                         goto fail_out;
 730                 }
 731
 732                 err = ramoops_parse_dt(pdev, pdata);
 733                 if (err < 0)
 734                         goto fail_out;
 735         }
 736
 737         /*
 738          * Only a single ramoops area allowed at a time, so fail extra
 739          * probes.
 740          */
 741         if (cxt->max_dump_cnt) {
 742                 pr_err("already initialized\n");
 743                 goto fail_out;
 744         }
 745
 746         /* Make sure we didn't get bogus platform data pointer. */
 747         if (!pdata) {
 748                 pr_err("NULL platform data\n");
 749                 goto fail_out;
 750         }
 751
 752         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 753                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 754                 pr_err("The memory size and the record/console size must be "
 755                         "non-zero\n");
 756                 goto fail_out;
 757         }
 758
 759         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 760                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 761         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 762                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 763         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 764                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 765         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 766                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 767
 768         cxt->size = pdata->mem_size;
 769         cxt->phys_addr = pdata->mem_address;
 770         cxt->memtype = pdata->mem_type;
 771         cxt->record_size = pdata->record_size;
 772         cxt->console_size = pdata->console_size;
 773         cxt->ftrace_size = pdata->ftrace_size;
 774         cxt->pmsg_size = pdata->pmsg_size;
 775         cxt->dump_oops = pdata->dump_oops;
 776         cxt->flags = pdata->flags;
 777         cxt->ecc_info = pdata->ecc_info;
 778
 779         paddr = cxt->phys_addr;
 780
 781         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 782                         - cxt->pmsg_size;
 783         err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
 784                                 dump_mem_sz, cxt->record_size,
 785                                 &cxt->max_dump_cnt, 0, 0);
 786         if (err)
 787                 goto fail_out;
 788
 789         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 790                                cxt->console_size, 0);
 791         if (err)
 792                 goto fail_init_cprz;
 793
 794         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 795                                 ? nr_cpu_ids
 796                                 : 1;
 797         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 798                                 cxt->ftrace_size, -1,
 799                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 800                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 801                                         ? PRZ_FLAG_NO_LOCK : 0);
 802         if (err)
 803                 goto fail_init_fprz;
 804
 805         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 806                                 cxt->pmsg_size, 0);
 807         if (err)
 808                 goto fail_init_mprz;
 809
 810         cxt->pstore.data = cxt;
 811         /*
 812          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 813          * have to handle dumps, we must have at least record_size buffer. And
 814          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 815          * ZERO_SIZE_PTR).
 816          */
 817         if (cxt->console_size)
 818                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 819         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 820         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 821         if (!cxt->pstore.buf) {
 822                 pr_err("cannot allocate pstore buffer\n");
 823                 err = -ENOMEM;
 824                 goto fail_clear;
 825         }
 826         spin_lock_init(&cxt->pstore.buf_lock);
 827
 828         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 829         if (cxt->console_size)
 830                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 831         if (cxt->ftrace_size)
 832                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 833         if (cxt->pmsg_size)
 834                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 835
 836         err = pstore_register(&cxt->pstore);
 837         if (err) {
 838                 pr_err("registering with pstore failed\n");
 839                 goto fail_buf;
 840         }
 841
 842         /*
 843          * Update the module parameter variables as well so they are visible
 844          * through /sys/module/ramoops/parameters/
 845          */
 846         mem_size = pdata->mem_size;
 847         mem_address = pdata->mem_address;
 848         record_size = pdata->record_size;
 849         dump_oops = pdata->dump_oops;
 850         ramoops_console_size = pdata->console_size;
 851         ramoops_pmsg_size = pdata->pmsg_size;
 852         ramoops_ftrace_size = pdata->ftrace_size;
 853
 854         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 855                 cxt->size, (unsigned long long)cxt->phys_addr,
 856                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 857
 858         return 0;
 859
 860 fail_buf:
 861         kfree(cxt->pstore.buf);
 862 fail_clear:
 863         cxt->pstore.bufsize = 0;
 864         persistent_ram_free(cxt->mprz);
 865 fail_init_mprz:
 866 fail_init_fprz:
 867         persistent_ram_free(cxt->cprz);
 868 fail_init_cprz:
 869         ramoops_free_przs(cxt);
 870 fail_out:
 871         return err;
 872 }
 873
 874 static int ramoops_remove(struct platform_device *pdev)
 875 {
 876         struct ramoops_context *cxt = &oops_cxt;
 877
 878         pstore_unregister(&cxt->pstore);
 879
 880         kfree(cxt->pstore.buf);
 881         cxt->pstore.bufsize = 0;
 882
 883         persistent_ram_free(cxt->mprz);
 884         persistent_ram_free(cxt->cprz);
 885         ramoops_free_przs(cxt);
 886
 887         return 0;
 888 }
 889
 890 static const struct of_device_id dt_match[] = {
 891         { .compatible = "ramoops" },
 892         {}
 893 };
 894
 895 static struct platform_driver ramoops_driver = {
 896         .probe          = ramoops_probe,
 897         .remove         = ramoops_remove,
 898         .driver         = {
 899                 .name           = "ramoops",
 900                 .of_match_table = dt_match,
 901         },
 902 };
 903
 904 static void ramoops_register_dummy(void)
 905 {
 906         if (!mem_size)
 907                 return;
 908
 909         pr_info("using module parameters\n");
 910
 911         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 912         if (!dummy_data) {
 913                 pr_info("could not allocate pdata\n");
 914                 return;
 915         }
 916
 917         dummy_data->mem_size = mem_size;
 918         dummy_data->mem_address = mem_address;
 919         dummy_data->mem_type = mem_type;
 920         dummy_data->record_size = record_size;
 921         dummy_data->console_size = ramoops_console_size;
 922         dummy_data->ftrace_size = ramoops_ftrace_size;
 923         dummy_data->pmsg_size = ramoops_pmsg_size;
 924         dummy_data->dump_oops = dump_oops;
 925         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 926
 927         /*
 928          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 929          * (using 1 byte for ECC isn't much of use anyway).
 930          */
 931         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 932
 933         dummy = platform_device_register_data(NULL, "ramoops", -1,
 934                         dummy_data, sizeof(struct ramoops_platform_data));
 935         if (IS_ERR(dummy)) {
 936                 pr_info("could not create platform device: %ld\n",
 937                         PTR_ERR(dummy));
 938         }
 939 }
 940
 941 static int __init ramoops_init(void)
 942 {
 943         ramoops_register_dummy();
 944         return platform_driver_register(&ramoops_driver);
 945 }
 946 postcore_initcall(ramoops_init);
 947
 948 static void __exit ramoops_exit(void)
 949 {
 950         platform_driver_unregister(&ramoops_driver);
 951         platform_device_unregister(dummy);
 952         kfree(dummy_data);
 953 }
 954 module_exit(ramoops_exit);
 955
 956 MODULE_LICENSE("GPL");
 957 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 958 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");