fs/pstore/ram.c

   1 /*
   2  * RAM Oops/Panic logger
   3  *
   4  * Copyright (C) 2010 Marco Stornelli <[email protected]>
   5  * Copyright (C) 2011 Kees Cook <[email protected]>
   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         /* Give up if we never existed or have hit the end. */
 137         if (!przs || i >= max)
 138                 return NULL;
 139
 140         prz = przs[i];
 141         if (!prz)
 142                 return NULL;
 143
 144         /* Update old/shadowed buffer. */
 145         if (update)
 146                 persistent_ram_save_old(prz);
 147
 148         if (!persistent_ram_old_size(prz))
 149                 return NULL;
 150
 151         *typep = type;
 152         *id = i;
 153
 154         return prz;
 155 }
 156
 157 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 158                                   bool *compressed)
 159 {
 160         char data_type;
 161         int header_length = 0;
 162
 163         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 164                         &time->tv_nsec, &data_type, &header_length) == 3) {
 165                 if (data_type == 'C')
 166                         *compressed = true;
 167                 else
 168                         *compressed = false;
 169         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 170                         &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
 171                         *compressed = false;
 172         } else {
 173                 time->tv_sec = 0;
 174                 time->tv_nsec = 0;
 175                 *compressed = false;
 176         }
 177         return header_length;
 178 }
 179
 180 static bool prz_ok(struct persistent_ram_zone *prz)
 181 {
 182         return !!prz && !!(persistent_ram_old_size(prz) +
 183                            persistent_ram_ecc_string(prz, NULL, 0));
 184 }
 185
 186 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 187                                   struct persistent_ram_zone *src)
 188 {
 189         size_t dest_size, src_size, total, dest_off, src_off;
 190         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 191         void *merged_buf;
 192         struct pstore_ftrace_record *drec, *srec, *mrec;
 193         size_t record_size = sizeof(struct pstore_ftrace_record);
 194
 195         dest_off = dest->old_log_size % record_size;
 196         dest_size = dest->old_log_size - dest_off;
 197
 198         src_off = src->old_log_size % record_size;
 199         src_size = src->old_log_size - src_off;
 200
 201         total = dest_size + src_size;
 202         merged_buf = kmalloc(total, GFP_KERNEL);
 203         if (!merged_buf)
 204                 return -ENOMEM;
 205
 206         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 207         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 208         mrec = (struct pstore_ftrace_record *)(merged_buf);
 209
 210         while (dest_size > 0 && src_size > 0) {
 211                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 212                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 213                         mrec[merged_idx++] = drec[dest_idx++];
 214                         dest_size -= record_size;
 215                 } else {
 216                         mrec[merged_idx++] = srec[src_idx++];
 217                         src_size -= record_size;
 218                 }
 219         }
 220
 221         while (dest_size > 0) {
 222                 mrec[merged_idx++] = drec[dest_idx++];
 223                 dest_size -= record_size;
 224         }
 225
 226         while (src_size > 0) {
 227                 mrec[merged_idx++] = srec[src_idx++];
 228                 src_size -= record_size;
 229         }
 230
 231         kfree(dest->old_log);
 232         dest->old_log = merged_buf;
 233         dest->old_log_size = total;
 234
 235         return 0;
 236 }
 237
 238 static ssize_t ramoops_pstore_read(struct pstore_record *record)
 239 {
 240         ssize_t size = 0;
 241         struct ramoops_context *cxt = record->psi->data;
 242         struct persistent_ram_zone *prz = NULL;
 243         int header_length = 0;
 244         bool free_prz = false;
 245
 246         /*
 247          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 248          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 249          * valid time stamps, so it is initialized to zero.
 250          */
 251         record->time.tv_sec = 0;
 252         record->time.tv_nsec = 0;
 253         record->compressed = false;
 254
 255         /* Find the next valid persistent_ram_zone for DMESG */
 256         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 257                 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
 258                                            cxt->max_dump_cnt, &record->id,
 259                                            &record->type,
 260                                            PSTORE_TYPE_DMESG, 1);
 261                 if (!prz_ok(prz))
 262                         continue;
 263                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 264                                                       &record->time,
 265                                                       &record->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, &record->id, &record->type,
 277                                            PSTORE_TYPE_CONSOLE, 0);
 278
 279         if (!prz_ok(prz))
 280                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 281                                            1, &record->id, &record->type,
 282                                            PSTORE_TYPE_PMSG, 0);
 283
 284         /* ftrace is last since it may want to dynamically allocate memory. */
 285         if (!prz_ok(prz)) {
 286                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
 287                         prz = ramoops_get_next_prz(cxt->fprzs,
 288                                         &cxt->ftrace_read_cnt, 1, &record->id,
 289                                         &record->type, PSTORE_TYPE_FTRACE, 0);
 290                 } else {
 291                         /*
 292                          * Build a new dummy record which combines all the
 293                          * per-cpu records including metadata and ecc info.
 294                          */
 295                         struct persistent_ram_zone *tmp_prz, *prz_next;
 296
 297                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 298                                           GFP_KERNEL);
 299                         if (!tmp_prz)
 300                                 return -ENOMEM;
 301                         free_prz = true;
 302
 303                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 304                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 305                                                 &cxt->ftrace_read_cnt,
 306                                                 cxt->max_ftrace_cnt,
 307                                                 &record->id,
 308                                                 &record->type,
 309                                                 PSTORE_TYPE_FTRACE, 0);
 310
 311                                 if (!prz_ok(prz_next))
 312                                         continue;
 313
 314                                 tmp_prz->ecc_info = prz_next->ecc_info;
 315                                 tmp_prz->corrected_bytes +=
 316                                                 prz_next->corrected_bytes;
 317                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 318                                 size = ftrace_log_combine(tmp_prz, prz_next);
 319                                 if (size)
 320                                         goto out;
 321                         }
 322                         record->id = 0;
 323                         prz = tmp_prz;
 324                 }
 325         }
 326
 327         if (!prz_ok(prz)) {
 328                 size = 0;
 329                 goto out;
 330         }
 331
 332         size = persistent_ram_old_size(prz) - header_length;
 333
 334         /* ECC correction notice */
 335         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 336
 337         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 338         if (record->buf == NULL) {
 339                 size = -ENOMEM;
 340                 goto out;
 341         }
 342
 343         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 344                size);
 345
 346         persistent_ram_ecc_string(prz, record->buf + size,
 347                                   record->ecc_notice_size + 1);
 348
 349 out:
 350         if (free_prz) {
 351                 kfree(prz->old_log);
 352                 kfree(prz);
 353         }
 354
 355         return size;
 356 }
 357
 358 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 359                                      bool compressed)
 360 {
 361         char *hdr;
 362         struct timespec timestamp;
 363         size_t len;
 364
 365         /* Report zeroed timestamp if called before timekeeping has resumed. */
 366         if (__getnstimeofday(&timestamp)) {
 367                 timestamp.tv_sec = 0;
 368                 timestamp.tv_nsec = 0;
 369         }
 370         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 371                 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
 372                 compressed ? 'C' : 'D');
 373         WARN_ON_ONCE(!hdr);
 374         len = hdr ? strlen(hdr) : 0;
 375         persistent_ram_write(prz, hdr, len);
 376         kfree(hdr);
 377
 378         return len;
 379 }
 380
 381 static int notrace ramoops_pstore_write(struct pstore_record *record)
 382 {
 383         struct ramoops_context *cxt = record->psi->data;
 384         struct persistent_ram_zone *prz;
 385         size_t size, hlen;
 386
 387         if (record->type == PSTORE_TYPE_CONSOLE) {
 388                 if (!cxt->cprz)
 389                         return -ENOMEM;
 390                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 391                 return 0;
 392         } else if (record->type == PSTORE_TYPE_FTRACE) {
 393                 int zonenum;
 394
 395                 if (!cxt->fprzs)
 396                         return -ENOMEM;
 397                 /*
 398                  * Choose zone by if we're using per-cpu buffers.
 399                  */
 400                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 401                         zonenum = smp_processor_id();
 402                 else
 403                         zonenum = 0;
 404
 405                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 406                                      record->size);
 407                 return 0;
 408         } else if (record->type == PSTORE_TYPE_PMSG) {
 409                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 410                 return -EINVAL;
 411         }
 412
 413         if (record->type != PSTORE_TYPE_DMESG)
 414                 return -EINVAL;
 415
 416         /*
 417          * Out of the various dmesg dump types, ramoops is currently designed
 418          * to only store crash logs, rather than storing general kernel logs.
 419          */
 420         if (record->reason != KMSG_DUMP_OOPS &&
 421             record->reason != KMSG_DUMP_PANIC)
 422                 return -EINVAL;
 423
 424         /* Skip Oopes when configured to do so. */
 425         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 426                 return -EINVAL;
 427
 428         /*
 429          * Explicitly only take the first part of any new crash.
 430          * If our buffer is larger than kmsg_bytes, this can never happen,
 431          * and if our buffer is smaller than kmsg_bytes, we don't want the
 432          * report split across multiple records.
 433          */
 434         if (record->part != 1)
 435                 return -ENOSPC;
 436
 437         if (!cxt->dprzs)
 438                 return -ENOSPC;
 439
 440         prz = cxt->dprzs[cxt->dump_write_cnt];
 441
 442         /* Build header and append record contents. */
 443         hlen = ramoops_write_kmsg_hdr(prz, record->compressed);
 444         size = record->size;
 445         if (size + hlen > prz->buffer_size)
 446                 size = prz->buffer_size - hlen;
 447         persistent_ram_write(prz, record->buf, size);
 448
 449         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 450
 451         return 0;
 452 }
 453
 454 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 455                                              const char __user *buf)
 456 {
 457         if (record->type == PSTORE_TYPE_PMSG) {
 458                 struct ramoops_context *cxt = record->psi->data;
 459
 460                 if (!cxt->mprz)
 461                         return -ENOMEM;
 462                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 463         }
 464
 465         return -EINVAL;
 466 }
 467
 468 static int ramoops_pstore_erase(struct pstore_record *record)
 469 {
 470         struct ramoops_context *cxt = record->psi->data;
 471         struct persistent_ram_zone *prz;
 472
 473         switch (record->type) {
 474         case PSTORE_TYPE_DMESG:
 475                 if (record->id >= cxt->max_dump_cnt)
 476                         return -EINVAL;
 477                 prz = cxt->dprzs[record->id];
 478                 break;
 479         case PSTORE_TYPE_CONSOLE:
 480                 prz = cxt->cprz;
 481                 break;
 482         case PSTORE_TYPE_FTRACE:
 483                 if (record->id >= cxt->max_ftrace_cnt)
 484                         return -EINVAL;
 485                 prz = cxt->fprzs[record->id];
 486                 break;
 487         case PSTORE_TYPE_PMSG:
 488                 prz = cxt->mprz;
 489                 break;
 490         default:
 491                 return -EINVAL;
 492         }
 493
 494         persistent_ram_free_old(prz);
 495         persistent_ram_zap(prz);
 496
 497         return 0;
 498 }
 499
 500 static struct ramoops_context oops_cxt = {
 501         .pstore = {
 502                 .owner  = THIS_MODULE,
 503                 .name   = "ramoops",
 504                 .open   = ramoops_pstore_open,
 505                 .read   = ramoops_pstore_read,
 506                 .write  = ramoops_pstore_write,
 507                 .write_user     = ramoops_pstore_write_user,
 508                 .erase  = ramoops_pstore_erase,
 509         },
 510 };
 511
 512 static void ramoops_free_przs(struct ramoops_context *cxt)
 513 {
 514         int i;
 515
 516         /* Free dump PRZs */
 517         if (cxt->dprzs) {
 518                 for (i = 0; i < cxt->max_dump_cnt; i++)
 519                         persistent_ram_free(cxt->dprzs[i]);
 520
 521                 kfree(cxt->dprzs);
 522                 cxt->max_dump_cnt = 0;
 523         }
 524
 525         /* Free ftrace PRZs */
 526         if (cxt->fprzs) {
 527                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 528                         persistent_ram_free(cxt->fprzs[i]);
 529                 kfree(cxt->fprzs);
 530                 cxt->max_ftrace_cnt = 0;
 531         }
 532 }
 533
 534 static int ramoops_init_przs(const char *name,
 535                              struct device *dev, struct ramoops_context *cxt,
 536                              struct persistent_ram_zone ***przs,
 537                              phys_addr_t *paddr, size_t mem_sz,
 538                              ssize_t record_size,
 539                              unsigned int *cnt, u32 sig, u32 flags)
 540 {
 541         int err = -ENOMEM;
 542         int i;
 543         size_t zone_sz;
 544         struct persistent_ram_zone **prz_ar;
 545
 546         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 547         if (mem_sz == 0 || record_size == 0) {
 548                 *cnt = 0;
 549                 return 0;
 550         }
 551
 552         /*
 553          * If we have a negative record size, calculate it based on
 554          * mem_sz / *cnt. If we have a positive record size, calculate
 555          * cnt from mem_sz / record_size.
 556          */
 557         if (record_size < 0) {
 558                 if (*cnt == 0)
 559                         return 0;
 560                 record_size = mem_sz / *cnt;
 561                 if (record_size == 0) {
 562                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 563                                 name, mem_sz, *cnt);
 564                         goto fail;
 565                 }
 566         } else {
 567                 *cnt = mem_sz / record_size;
 568                 if (*cnt == 0) {
 569                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 570                                 name, mem_sz, record_size);
 571                         goto fail;
 572                 }
 573         }
 574
 575         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 576                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 577                         name,
 578                         mem_sz, (unsigned long long)*paddr,
 579                         cxt->size, (unsigned long long)cxt->phys_addr);
 580                 goto fail;
 581         }
 582
 583         zone_sz = mem_sz / *cnt;
 584         if (!zone_sz) {
 585                 dev_err(dev, "%s zone size == 0\n", name);
 586                 goto fail;
 587         }
 588
 589         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 590         if (!prz_ar)
 591                 goto fail;
 592
 593         for (i = 0; i < *cnt; i++) {
 594                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 595                                                   &cxt->ecc_info,
 596                                                   cxt->memtype, flags);
 597                 if (IS_ERR(prz_ar[i])) {
 598                         err = PTR_ERR(prz_ar[i]);
 599                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 600                                 name, record_size,
 601                                 (unsigned long long)*paddr, err);
 602
 603                         while (i > 0) {
 604                                 i--;
 605                                 persistent_ram_free(prz_ar[i]);
 606                         }
 607                         kfree(prz_ar);
 608                         goto fail;
 609                 }
 610                 *paddr += zone_sz;
 611         }
 612
 613         *przs = prz_ar;
 614         return 0;
 615
 616 fail:
 617         *cnt = 0;
 618         return err;
 619 }
 620
 621 static int ramoops_init_prz(const char *name,
 622                             struct device *dev, struct ramoops_context *cxt,
 623                             struct persistent_ram_zone **prz,
 624                             phys_addr_t *paddr, size_t sz, u32 sig)
 625 {
 626         if (!sz)
 627                 return 0;
 628
 629         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 630                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 631                         name, sz, (unsigned long long)*paddr,
 632                         cxt->size, (unsigned long long)cxt->phys_addr);
 633                 return -ENOMEM;
 634         }
 635
 636         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 637                                   cxt->memtype, 0);
 638         if (IS_ERR(*prz)) {
 639                 int err = PTR_ERR(*prz);
 640
 641                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 642                         name, sz, (unsigned long long)*paddr, err);
 643                 return err;
 644         }
 645
 646         persistent_ram_zap(*prz);
 647
 648         *paddr += sz;
 649
 650         return 0;
 651 }
 652
 653 static int ramoops_parse_dt_size(struct platform_device *pdev,
 654                                  const char *propname, u32 *value)
 655 {
 656         u32 val32 = 0;
 657         int ret;
 658
 659         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 660         if (ret < 0 && ret != -EINVAL) {
 661                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 662                         propname, ret);
 663                 return ret;
 664         }
 665
 666         if (val32 > INT_MAX) {
 667                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 668                 return -EOVERFLOW;
 669         }
 670
 671         *value = val32;
 672         return 0;
 673 }
 674
 675 static int ramoops_parse_dt(struct platform_device *pdev,
 676                             struct ramoops_platform_data *pdata)
 677 {
 678         struct device_node *of_node = pdev->dev.of_node;
 679         struct resource *res;
 680         u32 value;
 681         int ret;
 682
 683         dev_dbg(&pdev->dev, "using Device Tree\n");
 684
 685         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 686         if (!res) {
 687                 dev_err(&pdev->dev,
 688                         "failed to locate DT /reserved-memory resource\n");
 689                 return -EINVAL;
 690         }
 691
 692         pdata->mem_size = resource_size(res);
 693         pdata->mem_address = res->start;
 694         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 695         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 696
 697 #define parse_size(name, field) {                                       \
 698                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 699                 if (ret < 0)                                            \
 700                         return ret;                                     \
 701                 field = value;                                          \
 702         }
 703
 704         parse_size("record-size", pdata->record_size);
 705         parse_size("console-size", pdata->console_size);
 706         parse_size("ftrace-size", pdata->ftrace_size);
 707         parse_size("pmsg-size", pdata->pmsg_size);
 708         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 709         parse_size("flags", pdata->flags);
 710
 711 #undef parse_size
 712
 713         return 0;
 714 }
 715
 716 static int ramoops_probe(struct platform_device *pdev)
 717 {
 718         struct device *dev = &pdev->dev;
 719         struct ramoops_platform_data *pdata = dev->platform_data;
 720         struct ramoops_context *cxt = &oops_cxt;
 721         size_t dump_mem_sz;
 722         phys_addr_t paddr;
 723         int err = -EINVAL;
 724
 725         if (dev_of_node(dev) && !pdata) {
 726                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 727                 if (!pdata) {
 728                         pr_err("cannot allocate platform data buffer\n");
 729                         err = -ENOMEM;
 730                         goto fail_out;
 731                 }
 732
 733                 err = ramoops_parse_dt(pdev, pdata);
 734                 if (err < 0)
 735                         goto fail_out;
 736         }
 737
 738         /*
 739          * Only a single ramoops area allowed at a time, so fail extra
 740          * probes.
 741          */
 742         if (cxt->max_dump_cnt) {
 743                 pr_err("already initialized\n");
 744                 goto fail_out;
 745         }
 746
 747         /* Make sure we didn't get bogus platform data pointer. */
 748         if (!pdata) {
 749                 pr_err("NULL platform data\n");
 750                 goto fail_out;
 751         }
 752
 753         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 754                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 755                 pr_err("The memory size and the record/console size must be "
 756                         "non-zero\n");
 757                 goto fail_out;
 758         }
 759
 760         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 761                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 762         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 763                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 764         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 765                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 766         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 767                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 768
 769         cxt->size = pdata->mem_size;
 770         cxt->phys_addr = pdata->mem_address;
 771         cxt->memtype = pdata->mem_type;
 772         cxt->record_size = pdata->record_size;
 773         cxt->console_size = pdata->console_size;
 774         cxt->ftrace_size = pdata->ftrace_size;
 775         cxt->pmsg_size = pdata->pmsg_size;
 776         cxt->dump_oops = pdata->dump_oops;
 777         cxt->flags = pdata->flags;
 778         cxt->ecc_info = pdata->ecc_info;
 779
 780         paddr = cxt->phys_addr;
 781
 782         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 783                         - cxt->pmsg_size;
 784         err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
 785                                 dump_mem_sz, cxt->record_size,
 786                                 &cxt->max_dump_cnt, 0, 0);
 787         if (err)
 788                 goto fail_out;
 789
 790         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 791                                cxt->console_size, 0);
 792         if (err)
 793                 goto fail_init_cprz;
 794
 795         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 796                                 ? nr_cpu_ids
 797                                 : 1;
 798         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 799                                 cxt->ftrace_size, -1,
 800                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 801                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 802                                         ? PRZ_FLAG_NO_LOCK : 0);
 803         if (err)
 804                 goto fail_init_fprz;
 805
 806         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 807                                 cxt->pmsg_size, 0);
 808         if (err)
 809                 goto fail_init_mprz;
 810
 811         cxt->pstore.data = cxt;
 812         /*
 813          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 814          * have to handle dumps, we must have at least record_size buffer. And
 815          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 816          * ZERO_SIZE_PTR).
 817          */
 818         if (cxt->console_size)
 819                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 820         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 821         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 822         if (!cxt->pstore.buf) {
 823                 pr_err("cannot allocate pstore buffer\n");
 824                 err = -ENOMEM;
 825                 goto fail_clear;
 826         }
 827         spin_lock_init(&cxt->pstore.buf_lock);
 828
 829         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 830         if (cxt->console_size)
 831                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 832         if (cxt->ftrace_size)
 833                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 834         if (cxt->pmsg_size)
 835                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 836
 837         err = pstore_register(&cxt->pstore);
 838         if (err) {
 839                 pr_err("registering with pstore failed\n");
 840                 goto fail_buf;
 841         }
 842
 843         /*
 844          * Update the module parameter variables as well so they are visible
 845          * through /sys/module/ramoops/parameters/
 846          */
 847         mem_size = pdata->mem_size;
 848         mem_address = pdata->mem_address;
 849         record_size = pdata->record_size;
 850         dump_oops = pdata->dump_oops;
 851         ramoops_console_size = pdata->console_size;
 852         ramoops_pmsg_size = pdata->pmsg_size;
 853         ramoops_ftrace_size = pdata->ftrace_size;
 854
 855         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 856                 cxt->size, (unsigned long long)cxt->phys_addr,
 857                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 858
 859         return 0;
 860
 861 fail_buf:
 862         kfree(cxt->pstore.buf);
 863 fail_clear:
 864         cxt->pstore.bufsize = 0;
 865         persistent_ram_free(cxt->mprz);
 866 fail_init_mprz:
 867 fail_init_fprz:
 868         persistent_ram_free(cxt->cprz);
 869 fail_init_cprz:
 870         ramoops_free_przs(cxt);
 871 fail_out:
 872         return err;
 873 }
 874
 875 static int ramoops_remove(struct platform_device *pdev)
 876 {
 877         struct ramoops_context *cxt = &oops_cxt;
 878
 879         pstore_unregister(&cxt->pstore);
 880
 881         kfree(cxt->pstore.buf);
 882         cxt->pstore.bufsize = 0;
 883
 884         persistent_ram_free(cxt->mprz);
 885         persistent_ram_free(cxt->cprz);
 886         ramoops_free_przs(cxt);
 887
 888         return 0;
 889 }
 890
 891 static const struct of_device_id dt_match[] = {
 892         { .compatible = "ramoops" },
 893         {}
 894 };
 895
 896 static struct platform_driver ramoops_driver = {
 897         .probe          = ramoops_probe,
 898         .remove         = ramoops_remove,
 899         .driver         = {
 900                 .name           = "ramoops",
 901                 .of_match_table = dt_match,
 902         },
 903 };
 904
 905 static void ramoops_register_dummy(void)
 906 {
 907         if (!mem_size)
 908                 return;
 909
 910         pr_info("using module parameters\n");
 911
 912         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 913         if (!dummy_data) {
 914                 pr_info("could not allocate pdata\n");
 915                 return;
 916         }
 917
 918         dummy_data->mem_size = mem_size;
 919         dummy_data->mem_address = mem_address;
 920         dummy_data->mem_type = mem_type;
 921         dummy_data->record_size = record_size;
 922         dummy_data->console_size = ramoops_console_size;
 923         dummy_data->ftrace_size = ramoops_ftrace_size;
 924         dummy_data->pmsg_size = ramoops_pmsg_size;
 925         dummy_data->dump_oops = dump_oops;
 926         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 927
 928         /*
 929          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 930          * (using 1 byte for ECC isn't much of use anyway).
 931          */
 932         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 933
 934         dummy = platform_device_register_data(NULL, "ramoops", -1,
 935                         dummy_data, sizeof(struct ramoops_platform_data));
 936         if (IS_ERR(dummy)) {
 937                 pr_info("could not create platform device: %ld\n",
 938                         PTR_ERR(dummy));
 939         }
 940 }
 941
 942 static int __init ramoops_init(void)
 943 {
 944         ramoops_register_dummy();
 945         return platform_driver_register(&ramoops_driver);
 946 }
 947 postcore_initcall(ramoops_init);
 948
 949 static void __exit ramoops_exit(void)
 950 {
 951         platform_driver_unregister(&ramoops_driver);
 952         platform_device_unregister(dummy);
 953         kfree(dummy_data);
 954 }
 955 module_exit(ramoops_exit);
 956
 957 MODULE_LICENSE("GPL");
 958 MODULE_AUTHOR("Marco Stornelli <[email protected]>");
 959 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");