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/io.h>
  31 #include <linux/ioport.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/slab.h>
  34 #include <linux/compiler.h>
  35 #include <linux/pstore_ram.h>
  36 #include <linux/of.h>
  37 #include <linux/of_address.h>
  38
  39 #define RAMOOPS_KERNMSG_HDR "===="
  40 #define MIN_MEM_SIZE 4096UL
  41
  42 static ulong record_size = MIN_MEM_SIZE;
  43 module_param(record_size, ulong, 0400);
  44 MODULE_PARM_DESC(record_size,
  45                 "size of each dump done on oops/panic");
  46
  47 static ulong ramoops_console_size = MIN_MEM_SIZE;
  48 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  49 MODULE_PARM_DESC(console_size, "size of kernel console log");
  50
  51 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  52 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  53 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  54
  55 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  56 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  57 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  58
  59 static unsigned long long mem_address;
  60 module_param_hw(mem_address, ullong, other, 0400);
  61 MODULE_PARM_DESC(mem_address,
  62                 "start of reserved RAM used to store oops/panic logs");
  63
  64 static ulong mem_size;
  65 module_param(mem_size, ulong, 0400);
  66 MODULE_PARM_DESC(mem_size,
  67                 "size of reserved RAM used to store oops/panic logs");
  68
  69 static unsigned int mem_type;
  70 module_param(mem_type, uint, 0600);
  71 MODULE_PARM_DESC(mem_type,
  72                 "set to 1 to try to use unbuffered memory (default 0)");
  73
  74 static int dump_oops = 1;
  75 module_param(dump_oops, int, 0600);
  76 MODULE_PARM_DESC(dump_oops,
  77                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  78
  79 static int ramoops_ecc;
  80 module_param_named(ecc, ramoops_ecc, int, 0600);
  81 MODULE_PARM_DESC(ramoops_ecc,
  82                 "if non-zero, the option enables ECC support and specifies "
  83                 "ECC buffer size in bytes (1 is a special value, means 16 "
  84                 "bytes ECC)");
  85
  86 struct ramoops_context {
  87         struct persistent_ram_zone **dprzs;     /* Oops dump zones */
  88         struct persistent_ram_zone *cprz;       /* Console zone */
  89         struct persistent_ram_zone **fprzs;     /* Ftrace zones */
  90         struct persistent_ram_zone *mprz;       /* PMSG zone */
  91         phys_addr_t phys_addr;
  92         unsigned long size;
  93         unsigned int memtype;
  94         size_t record_size;
  95         size_t console_size;
  96         size_t ftrace_size;
  97         size_t pmsg_size;
  98         int dump_oops;
  99         u32 flags;
 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 max_ftrace_cnt;
 107         unsigned int ftrace_read_cnt;
 108         unsigned int pmsg_read_cnt;
 109         struct pstore_info pstore;
 110 };
 111
 112 static struct platform_device *dummy;
 113 static struct ramoops_platform_data *dummy_data;
 114
 115 static int ramoops_pstore_open(struct pstore_info *psi)
 116 {
 117         struct ramoops_context *cxt = psi->data;
 118
 119         cxt->dump_read_cnt = 0;
 120         cxt->console_read_cnt = 0;
 121         cxt->ftrace_read_cnt = 0;
 122         cxt->pmsg_read_cnt = 0;
 123         return 0;
 124 }
 125
 126 static struct persistent_ram_zone *
 127 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 128                      u64 *id,
 129                      enum pstore_type_id *typep, enum pstore_type_id type,
 130                      bool update)
 131 {
 132         struct persistent_ram_zone *prz;
 133         int i = (*c)++;
 134
 135         /* Give up if we never existed or have hit the end. */
 136         if (!przs || 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 timespec64 *time,
 157                                   bool *compressed)
 158 {
 159         char data_type;
 160         int header_length = 0;
 161
 162         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
 163                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
 164                    &header_length) == 3) {
 165                 time->tv_nsec *= 1000;
 166                 if (data_type == 'C')
 167                         *compressed = true;
 168                 else
 169                         *compressed = false;
 170         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 171                           (time64_t *)&time->tv_sec, &time->tv_nsec,
 172                           &header_length) == 2) {
 173                 time->tv_nsec *= 1000;
 174                 *compressed = false;
 175         } else {
 176                 time->tv_sec = 0;
 177                 time->tv_nsec = 0;
 178                 *compressed = false;
 179         }
 180         return header_length;
 181 }
 182
 183 static bool prz_ok(struct persistent_ram_zone *prz)
 184 {
 185         return !!prz && !!(persistent_ram_old_size(prz) +
 186                            persistent_ram_ecc_string(prz, NULL, 0));
 187 }
 188
 189 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 190                                   struct persistent_ram_zone *src)
 191 {
 192         size_t dest_size, src_size, total, dest_off, src_off;
 193         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 194         void *merged_buf;
 195         struct pstore_ftrace_record *drec, *srec, *mrec;
 196         size_t record_size = sizeof(struct pstore_ftrace_record);
 197
 198         dest_off = dest->old_log_size % record_size;
 199         dest_size = dest->old_log_size - dest_off;
 200
 201         src_off = src->old_log_size % record_size;
 202         src_size = src->old_log_size - src_off;
 203
 204         total = dest_size + src_size;
 205         merged_buf = kmalloc(total, GFP_KERNEL);
 206         if (!merged_buf)
 207                 return -ENOMEM;
 208
 209         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 210         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 211         mrec = (struct pstore_ftrace_record *)(merged_buf);
 212
 213         while (dest_size > 0 && src_size > 0) {
 214                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 215                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 216                         mrec[merged_idx++] = drec[dest_idx++];
 217                         dest_size -= record_size;
 218                 } else {
 219                         mrec[merged_idx++] = srec[src_idx++];
 220                         src_size -= record_size;
 221                 }
 222         }
 223
 224         while (dest_size > 0) {
 225                 mrec[merged_idx++] = drec[dest_idx++];
 226                 dest_size -= record_size;
 227         }
 228
 229         while (src_size > 0) {
 230                 mrec[merged_idx++] = srec[src_idx++];
 231                 src_size -= record_size;
 232         }
 233
 234         kfree(dest->old_log);
 235         dest->old_log = merged_buf;
 236         dest->old_log_size = total;
 237
 238         return 0;
 239 }
 240
 241 static ssize_t ramoops_pstore_read(struct pstore_record *record)
 242 {
 243         ssize_t size = 0;
 244         struct ramoops_context *cxt = record->psi->data;
 245         struct persistent_ram_zone *prz = NULL;
 246         int header_length = 0;
 247         bool free_prz = false;
 248
 249         /*
 250          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 251          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 252          * valid time stamps, so it is initialized to zero.
 253          */
 254         record->time.tv_sec = 0;
 255         record->time.tv_nsec = 0;
 256         record->compressed = false;
 257
 258         /* Find the next valid persistent_ram_zone for DMESG */
 259         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 260                 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
 261                                            cxt->max_dump_cnt, &record->id,
 262                                            &record->type,
 263                                            PSTORE_TYPE_DMESG, 1);
 264                 if (!prz_ok(prz))
 265                         continue;
 266                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 267                                                       &record->time,
 268                                                       &record->compressed);
 269                 /* Clear and skip this DMESG record if it has no valid header */
 270                 if (!header_length) {
 271                         persistent_ram_free_old(prz);
 272                         persistent_ram_zap(prz);
 273                         prz = NULL;
 274                 }
 275         }
 276
 277         if (!prz_ok(prz))
 278                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 279                                            1, &record->id, &record->type,
 280                                            PSTORE_TYPE_CONSOLE, 0);
 281
 282         if (!prz_ok(prz))
 283                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 284                                            1, &record->id, &record->type,
 285                                            PSTORE_TYPE_PMSG, 0);
 286
 287         /* ftrace is last since it may want to dynamically allocate memory. */
 288         if (!prz_ok(prz)) {
 289                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
 290                         prz = ramoops_get_next_prz(cxt->fprzs,
 291                                         &cxt->ftrace_read_cnt, 1, &record->id,
 292                                         &record->type, PSTORE_TYPE_FTRACE, 0);
 293                 } else {
 294                         /*
 295                          * Build a new dummy record which combines all the
 296                          * per-cpu records including metadata and ecc info.
 297                          */
 298                         struct persistent_ram_zone *tmp_prz, *prz_next;
 299
 300                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 301                                           GFP_KERNEL);
 302                         if (!tmp_prz)
 303                                 return -ENOMEM;
 304                         prz = tmp_prz;
 305                         free_prz = true;
 306
 307                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 308                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 309                                                 &cxt->ftrace_read_cnt,
 310                                                 cxt->max_ftrace_cnt,
 311                                                 &record->id,
 312                                                 &record->type,
 313                                                 PSTORE_TYPE_FTRACE, 0);
 314
 315                                 if (!prz_ok(prz_next))
 316                                         continue;
 317
 318                                 tmp_prz->ecc_info = prz_next->ecc_info;
 319                                 tmp_prz->corrected_bytes +=
 320                                                 prz_next->corrected_bytes;
 321                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 322                                 size = ftrace_log_combine(tmp_prz, prz_next);
 323                                 if (size)
 324                                         goto out;
 325                         }
 326                         record->id = 0;
 327                 }
 328         }
 329
 330         if (!prz_ok(prz)) {
 331                 size = 0;
 332                 goto out;
 333         }
 334
 335         size = persistent_ram_old_size(prz) - header_length;
 336
 337         /* ECC correction notice */
 338         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 339
 340         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 341         if (record->buf == NULL) {
 342                 size = -ENOMEM;
 343                 goto out;
 344         }
 345
 346         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 347                size);
 348
 349         persistent_ram_ecc_string(prz, record->buf + size,
 350                                   record->ecc_notice_size + 1);
 351
 352 out:
 353         if (free_prz) {
 354                 kfree(prz->old_log);
 355                 kfree(prz);
 356         }
 357
 358         return size;
 359 }
 360
 361 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 362                                      struct pstore_record *record)
 363 {
 364         char *hdr;
 365         size_t len;
 366
 367         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
 368                 (time64_t)record->time.tv_sec,
 369                 record->time.tv_nsec / 1000,
 370                 record->compressed ? 'C' : 'D');
 371         WARN_ON_ONCE(!hdr);
 372         len = hdr ? strlen(hdr) : 0;
 373         persistent_ram_write(prz, hdr, len);
 374         kfree(hdr);
 375
 376         return len;
 377 }
 378
 379 static int notrace ramoops_pstore_write(struct pstore_record *record)
 380 {
 381         struct ramoops_context *cxt = record->psi->data;
 382         struct persistent_ram_zone *prz;
 383         size_t size, hlen;
 384
 385         if (record->type == PSTORE_TYPE_CONSOLE) {
 386                 if (!cxt->cprz)
 387                         return -ENOMEM;
 388                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 389                 return 0;
 390         } else if (record->type == PSTORE_TYPE_FTRACE) {
 391                 int zonenum;
 392
 393                 if (!cxt->fprzs)
 394                         return -ENOMEM;
 395                 /*
 396                  * Choose zone by if we're using per-cpu buffers.
 397                  */
 398                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 399                         zonenum = smp_processor_id();
 400                 else
 401                         zonenum = 0;
 402
 403                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 404                                      record->size);
 405                 return 0;
 406         } else if (record->type == PSTORE_TYPE_PMSG) {
 407                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 408                 return -EINVAL;
 409         }
 410
 411         if (record->type != PSTORE_TYPE_DMESG)
 412                 return -EINVAL;
 413
 414         /*
 415          * Out of the various dmesg dump types, ramoops is currently designed
 416          * to only store crash logs, rather than storing general kernel logs.
 417          */
 418         if (record->reason != KMSG_DUMP_OOPS &&
 419             record->reason != KMSG_DUMP_PANIC)
 420                 return -EINVAL;
 421
 422         /* Skip Oopes when configured to do so. */
 423         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 424                 return -EINVAL;
 425
 426         /*
 427          * Explicitly only take the first part of any new crash.
 428          * If our buffer is larger than kmsg_bytes, this can never happen,
 429          * and if our buffer is smaller than kmsg_bytes, we don't want the
 430          * report split across multiple records.
 431          */
 432         if (record->part != 1)
 433                 return -ENOSPC;
 434
 435         if (!cxt->dprzs)
 436                 return -ENOSPC;
 437
 438         prz = cxt->dprzs[cxt->dump_write_cnt];
 439
 440         /*
 441          * Since this is a new crash dump, we need to reset the buffer in
 442          * case it still has an old dump present. Without this, the new dump
 443          * will get appended, which would seriously confuse anything trying
 444          * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
 445          * expects to find a dump header in the beginning of buffer data, so
 446          * we must to reset the buffer values, in order to ensure that the
 447          * header will be written to the beginning of the buffer.
 448          */
 449         persistent_ram_zap(prz);
 450
 451         /* Build header and append record contents. */
 452         hlen = ramoops_write_kmsg_hdr(prz, record);
 453         size = record->size;
 454         if (size + hlen > prz->buffer_size)
 455                 size = prz->buffer_size - hlen;
 456         persistent_ram_write(prz, record->buf, size);
 457
 458         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 459
 460         return 0;
 461 }
 462
 463 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 464                                              const char __user *buf)
 465 {
 466         if (record->type == PSTORE_TYPE_PMSG) {
 467                 struct ramoops_context *cxt = record->psi->data;
 468
 469                 if (!cxt->mprz)
 470                         return -ENOMEM;
 471                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 472         }
 473
 474         return -EINVAL;
 475 }
 476
 477 static int ramoops_pstore_erase(struct pstore_record *record)
 478 {
 479         struct ramoops_context *cxt = record->psi->data;
 480         struct persistent_ram_zone *prz;
 481
 482         switch (record->type) {
 483         case PSTORE_TYPE_DMESG:
 484                 if (record->id >= cxt->max_dump_cnt)
 485                         return -EINVAL;
 486                 prz = cxt->dprzs[record->id];
 487                 break;
 488         case PSTORE_TYPE_CONSOLE:
 489                 prz = cxt->cprz;
 490                 break;
 491         case PSTORE_TYPE_FTRACE:
 492                 if (record->id >= cxt->max_ftrace_cnt)
 493                         return -EINVAL;
 494                 prz = cxt->fprzs[record->id];
 495                 break;
 496         case PSTORE_TYPE_PMSG:
 497                 prz = cxt->mprz;
 498                 break;
 499         default:
 500                 return -EINVAL;
 501         }
 502
 503         persistent_ram_free_old(prz);
 504         persistent_ram_zap(prz);
 505
 506         return 0;
 507 }
 508
 509 static struct ramoops_context oops_cxt = {
 510         .pstore = {
 511                 .owner  = THIS_MODULE,
 512                 .name   = "ramoops",
 513                 .open   = ramoops_pstore_open,
 514                 .read   = ramoops_pstore_read,
 515                 .write  = ramoops_pstore_write,
 516                 .write_user     = ramoops_pstore_write_user,
 517                 .erase  = ramoops_pstore_erase,
 518         },
 519 };
 520
 521 static void ramoops_free_przs(struct ramoops_context *cxt)
 522 {
 523         int i;
 524
 525         /* Free dump PRZs */
 526         if (cxt->dprzs) {
 527                 for (i = 0; i < cxt->max_dump_cnt; i++)
 528                         persistent_ram_free(cxt->dprzs[i]);
 529
 530                 kfree(cxt->dprzs);
 531                 cxt->max_dump_cnt = 0;
 532         }
 533
 534         /* Free ftrace PRZs */
 535         if (cxt->fprzs) {
 536                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 537                         persistent_ram_free(cxt->fprzs[i]);
 538                 kfree(cxt->fprzs);
 539                 cxt->max_ftrace_cnt = 0;
 540         }
 541 }
 542
 543 static int ramoops_init_przs(const char *name,
 544                              struct device *dev, struct ramoops_context *cxt,
 545                              struct persistent_ram_zone ***przs,
 546                              phys_addr_t *paddr, size_t mem_sz,
 547                              ssize_t record_size,
 548                              unsigned int *cnt, u32 sig, u32 flags)
 549 {
 550         int err = -ENOMEM;
 551         int i;
 552         size_t zone_sz;
 553         struct persistent_ram_zone **prz_ar;
 554
 555         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 556         if (mem_sz == 0 || record_size == 0) {
 557                 *cnt = 0;
 558                 return 0;
 559         }
 560
 561         /*
 562          * If we have a negative record size, calculate it based on
 563          * mem_sz / *cnt. If we have a positive record size, calculate
 564          * cnt from mem_sz / record_size.
 565          */
 566         if (record_size < 0) {
 567                 if (*cnt == 0)
 568                         return 0;
 569                 record_size = mem_sz / *cnt;
 570                 if (record_size == 0) {
 571                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 572                                 name, mem_sz, *cnt);
 573                         goto fail;
 574                 }
 575         } else {
 576                 *cnt = mem_sz / record_size;
 577                 if (*cnt == 0) {
 578                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 579                                 name, mem_sz, record_size);
 580                         goto fail;
 581                 }
 582         }
 583
 584         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 585                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 586                         name,
 587                         mem_sz, (unsigned long long)*paddr,
 588                         cxt->size, (unsigned long long)cxt->phys_addr);
 589                 goto fail;
 590         }
 591
 592         zone_sz = mem_sz / *cnt;
 593         if (!zone_sz) {
 594                 dev_err(dev, "%s zone size == 0\n", name);
 595                 goto fail;
 596         }
 597
 598         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 599         if (!prz_ar)
 600                 goto fail;
 601
 602         for (i = 0; i < *cnt; i++) {
 603                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 604                                                   &cxt->ecc_info,
 605                                                   cxt->memtype, flags);
 606                 if (IS_ERR(prz_ar[i])) {
 607                         err = PTR_ERR(prz_ar[i]);
 608                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 609                                 name, record_size,
 610                                 (unsigned long long)*paddr, err);
 611
 612                         while (i > 0) {
 613                                 i--;
 614                                 persistent_ram_free(prz_ar[i]);
 615                         }
 616                         kfree(prz_ar);
 617                         goto fail;
 618                 }
 619                 *paddr += zone_sz;
 620         }
 621
 622         *przs = prz_ar;
 623         return 0;
 624
 625 fail:
 626         *cnt = 0;
 627         return err;
 628 }
 629
 630 static int ramoops_init_prz(const char *name,
 631                             struct device *dev, struct ramoops_context *cxt,
 632                             struct persistent_ram_zone **prz,
 633                             phys_addr_t *paddr, size_t sz, u32 sig)
 634 {
 635         if (!sz)
 636                 return 0;
 637
 638         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 639                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 640                         name, sz, (unsigned long long)*paddr,
 641                         cxt->size, (unsigned long long)cxt->phys_addr);
 642                 return -ENOMEM;
 643         }
 644
 645         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 646                                   cxt->memtype, 0);
 647         if (IS_ERR(*prz)) {
 648                 int err = PTR_ERR(*prz);
 649
 650                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 651                         name, sz, (unsigned long long)*paddr, err);
 652                 return err;
 653         }
 654
 655         persistent_ram_zap(*prz);
 656
 657         *paddr += sz;
 658
 659         return 0;
 660 }
 661
 662 static int ramoops_parse_dt_size(struct platform_device *pdev,
 663                                  const char *propname, u32 *value)
 664 {
 665         u32 val32 = 0;
 666         int ret;
 667
 668         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 669         if (ret < 0 && ret != -EINVAL) {
 670                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 671                         propname, ret);
 672                 return ret;
 673         }
 674
 675         if (val32 > INT_MAX) {
 676                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 677                 return -EOVERFLOW;
 678         }
 679
 680         *value = val32;
 681         return 0;
 682 }
 683
 684 static int ramoops_parse_dt(struct platform_device *pdev,
 685                             struct ramoops_platform_data *pdata)
 686 {
 687         struct device_node *of_node = pdev->dev.of_node;
 688         struct resource *res;
 689         u32 value;
 690         int ret;
 691
 692         dev_dbg(&pdev->dev, "using Device Tree\n");
 693
 694         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 695         if (!res) {
 696                 dev_err(&pdev->dev,
 697                         "failed to locate DT /reserved-memory resource\n");
 698                 return -EINVAL;
 699         }
 700
 701         pdata->mem_size = resource_size(res);
 702         pdata->mem_address = res->start;
 703         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 704         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 705
 706 #define parse_size(name, field) {                                       \
 707                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 708                 if (ret < 0)                                            \
 709                         return ret;                                     \
 710                 field = value;                                          \
 711         }
 712
 713         parse_size("record-size", pdata->record_size);
 714         parse_size("console-size", pdata->console_size);
 715         parse_size("ftrace-size", pdata->ftrace_size);
 716         parse_size("pmsg-size", pdata->pmsg_size);
 717         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 718         parse_size("flags", pdata->flags);
 719
 720 #undef parse_size
 721
 722         return 0;
 723 }
 724
 725 static int ramoops_probe(struct platform_device *pdev)
 726 {
 727         struct device *dev = &pdev->dev;
 728         struct ramoops_platform_data *pdata = dev->platform_data;
 729         struct ramoops_platform_data pdata_local;
 730         struct ramoops_context *cxt = &oops_cxt;
 731         size_t dump_mem_sz;
 732         phys_addr_t paddr;
 733         int err = -EINVAL;
 734
 735         if (dev_of_node(dev) && !pdata) {
 736                 pdata = &pdata_local;
 737                 memset(pdata, 0, sizeof(*pdata));
 738
 739                 err = ramoops_parse_dt(pdev, pdata);
 740                 if (err < 0)
 741                         goto fail_out;
 742         }
 743
 744         /*
 745          * Only a single ramoops area allowed at a time, so fail extra
 746          * probes.
 747          */
 748         if (cxt->max_dump_cnt) {
 749                 pr_err("already initialized\n");
 750                 goto fail_out;
 751         }
 752
 753         /* Make sure we didn't get bogus platform data pointer. */
 754         if (!pdata) {
 755                 pr_err("NULL platform data\n");
 756                 goto fail_out;
 757         }
 758
 759         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 760                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 761                 pr_err("The memory size and the record/console size must be "
 762                         "non-zero\n");
 763                 goto fail_out;
 764         }
 765
 766         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 767                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 768         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 769                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 770         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 771                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 772         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 773                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 774
 775         cxt->size = pdata->mem_size;
 776         cxt->phys_addr = pdata->mem_address;
 777         cxt->memtype = pdata->mem_type;
 778         cxt->record_size = pdata->record_size;
 779         cxt->console_size = pdata->console_size;
 780         cxt->ftrace_size = pdata->ftrace_size;
 781         cxt->pmsg_size = pdata->pmsg_size;
 782         cxt->dump_oops = pdata->dump_oops;
 783         cxt->flags = pdata->flags;
 784         cxt->ecc_info = pdata->ecc_info;
 785
 786         paddr = cxt->phys_addr;
 787
 788         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 789                         - cxt->pmsg_size;
 790         err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
 791                                 dump_mem_sz, cxt->record_size,
 792                                 &cxt->max_dump_cnt, 0, 0);
 793         if (err)
 794                 goto fail_out;
 795
 796         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 797                                cxt->console_size, 0);
 798         if (err)
 799                 goto fail_init_cprz;
 800
 801         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 802                                 ? nr_cpu_ids
 803                                 : 1;
 804         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 805                                 cxt->ftrace_size, -1,
 806                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 807                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 808                                         ? PRZ_FLAG_NO_LOCK : 0);
 809         if (err)
 810                 goto fail_init_fprz;
 811
 812         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 813                                 cxt->pmsg_size, 0);
 814         if (err)
 815                 goto fail_init_mprz;
 816
 817         cxt->pstore.data = cxt;
 818         /*
 819          * Prepare frontend flags based on which areas are initialized.
 820          * For ramoops_init_przs() cases, the "max count" variable tells
 821          * if there are regions present. For ramoops_init_prz() cases,
 822          * the single region size is how to check.
 823          */
 824         cxt->pstore.flags = 0;
 825         if (cxt->max_dump_cnt)
 826                 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
 827         if (cxt->console_size)
 828                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 829         if (cxt->max_ftrace_cnt)
 830                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 831         if (cxt->pmsg_size)
 832                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 833
 834         /*
 835          * Since bufsize is only used for dmesg crash dumps, it
 836          * must match the size of the dprz record (after PRZ header
 837          * and ECC bytes have been accounted for).
 838          */
 839         if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
 840                 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
 841                 cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
 842                 if (!cxt->pstore.buf) {
 843                         pr_err("cannot allocate pstore crash dump buffer\n");
 844                         err = -ENOMEM;
 845                         goto fail_clear;
 846                 }
 847         }
 848
 849         err = pstore_register(&cxt->pstore);
 850         if (err) {
 851                 pr_err("registering with pstore failed\n");
 852                 goto fail_buf;
 853         }
 854
 855         /*
 856          * Update the module parameter variables as well so they are visible
 857          * through /sys/module/ramoops/parameters/
 858          */
 859         mem_size = pdata->mem_size;
 860         mem_address = pdata->mem_address;
 861         record_size = pdata->record_size;
 862         dump_oops = pdata->dump_oops;
 863         ramoops_console_size = pdata->console_size;
 864         ramoops_pmsg_size = pdata->pmsg_size;
 865         ramoops_ftrace_size = pdata->ftrace_size;
 866
 867         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 868                 cxt->size, (unsigned long long)cxt->phys_addr,
 869                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 870
 871         return 0;
 872
 873 fail_buf:
 874         kfree(cxt->pstore.buf);
 875 fail_clear:
 876         cxt->pstore.bufsize = 0;
 877         persistent_ram_free(cxt->mprz);
 878 fail_init_mprz:
 879 fail_init_fprz:
 880         persistent_ram_free(cxt->cprz);
 881 fail_init_cprz:
 882         ramoops_free_przs(cxt);
 883 fail_out:
 884         return err;
 885 }
 886
 887 static int ramoops_remove(struct platform_device *pdev)
 888 {
 889         struct ramoops_context *cxt = &oops_cxt;
 890
 891         pstore_unregister(&cxt->pstore);
 892
 893         kfree(cxt->pstore.buf);
 894         cxt->pstore.bufsize = 0;
 895
 896         persistent_ram_free(cxt->mprz);
 897         persistent_ram_free(cxt->cprz);
 898         ramoops_free_przs(cxt);
 899
 900         return 0;
 901 }
 902
 903 static const struct of_device_id dt_match[] = {
 904         { .compatible = "ramoops" },
 905         {}
 906 };
 907
 908 static struct platform_driver ramoops_driver = {
 909         .probe          = ramoops_probe,
 910         .remove         = ramoops_remove,
 911         .driver         = {
 912                 .name           = "ramoops",
 913                 .of_match_table = dt_match,
 914         },
 915 };
 916
 917 static inline void ramoops_unregister_dummy(void)
 918 {
 919         platform_device_unregister(dummy);
 920         dummy = NULL;
 921
 922         kfree(dummy_data);
 923         dummy_data = NULL;
 924 }
 925
 926 static void __init ramoops_register_dummy(void)
 927 {
 928         /*
 929          * Prepare a dummy platform data structure to carry the module
 930          * parameters. If mem_size isn't set, then there are no module
 931          * parameters, and we can skip this.
 932          */
 933         if (!mem_size)
 934                 return;
 935
 936         pr_info("using module parameters\n");
 937
 938         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 939         if (!dummy_data) {
 940                 pr_info("could not allocate pdata\n");
 941                 return;
 942         }
 943
 944         dummy_data->mem_size = mem_size;
 945         dummy_data->mem_address = mem_address;
 946         dummy_data->mem_type = mem_type;
 947         dummy_data->record_size = record_size;
 948         dummy_data->console_size = ramoops_console_size;
 949         dummy_data->ftrace_size = ramoops_ftrace_size;
 950         dummy_data->pmsg_size = ramoops_pmsg_size;
 951         dummy_data->dump_oops = dump_oops;
 952         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 953
 954         /*
 955          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 956          * (using 1 byte for ECC isn't much of use anyway).
 957          */
 958         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 959
 960         dummy = platform_device_register_data(NULL, "ramoops", -1,
 961                         dummy_data, sizeof(struct ramoops_platform_data));
 962         if (IS_ERR(dummy)) {
 963                 pr_info("could not create platform device: %ld\n",
 964                         PTR_ERR(dummy));
 965                 dummy = NULL;
 966                 ramoops_unregister_dummy();
 967         }
 968 }
 969
 970 static int __init ramoops_init(void)
 971 {
 972         int ret;
 973
 974         ramoops_register_dummy();
 975         ret = platform_driver_register(&ramoops_driver);
 976         if (ret != 0)
 977                 ramoops_unregister_dummy();
 978
 979         return ret;
 980 }
 981 postcore_initcall(ramoops_init);
 982
 983 static void __exit ramoops_exit(void)
 984 {
 985         platform_driver_unregister(&ramoops_driver);
 986         ramoops_unregister_dummy();
 987 }
 988 module_exit(ramoops_exit);
 989
 990 MODULE_LICENSE("GPL");
 991 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 992 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");