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[], int id,
 128                      struct pstore_record *record)
 129 {
 130         struct persistent_ram_zone *prz;
 131         bool update = (record->type == PSTORE_TYPE_DMESG);
 132
 133         /* Give up if we never existed or have hit the end. */
 134         if (!przs)
 135                 return NULL;
 136
 137         prz = przs[id];
 138         if (!prz)
 139                 return NULL;
 140
 141         /* Update old/shadowed buffer. */
 142         if (update)
 143                 persistent_ram_save_old(prz);
 144
 145         if (!persistent_ram_old_size(prz))
 146                 return NULL;
 147
 148         record->type = prz->type;
 149         record->id = id;
 150
 151         return prz;
 152 }
 153
 154 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
 155                                   bool *compressed)
 156 {
 157         char data_type;
 158         int header_length = 0;
 159
 160         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
 161                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
 162                    &header_length) == 3) {
 163                 if (data_type == 'C')
 164                         *compressed = true;
 165                 else
 166                         *compressed = false;
 167         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 168                           (time64_t *)&time->tv_sec, &time->tv_nsec,
 169                           &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(struct pstore_record *record)
 238 {
 239         ssize_t size = 0;
 240         struct ramoops_context *cxt = record->psi->data;
 241         struct persistent_ram_zone *prz = NULL;
 242         int header_length = 0;
 243         bool free_prz = false;
 244
 245         /*
 246          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 247          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 248          * valid time stamps, so it is initialized to zero.
 249          */
 250         record->time.tv_sec = 0;
 251         record->time.tv_nsec = 0;
 252         record->compressed = false;
 253
 254         /* Find the next valid persistent_ram_zone for DMESG */
 255         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 256                 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
 257                                            record);
 258                 if (!prz_ok(prz))
 259                         continue;
 260                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 261                                                       &record->time,
 262                                                       &record->compressed);
 263                 /* Clear and skip this DMESG record if it has no valid header */
 264                 if (!header_length) {
 265                         persistent_ram_free_old(prz);
 266                         persistent_ram_zap(prz);
 267                         prz = NULL;
 268                 }
 269         }
 270
 271         if (!prz_ok(prz) && !cxt->console_read_cnt++)
 272                 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
 273
 274         if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
 275                 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
 276
 277         /* ftrace is last since it may want to dynamically allocate memory. */
 278         if (!prz_ok(prz)) {
 279                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
 280                     !cxt->ftrace_read_cnt++) {
 281                         prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
 282                                                    record);
 283                 } else {
 284                         /*
 285                          * Build a new dummy record which combines all the
 286                          * per-cpu records including metadata and ecc info.
 287                          */
 288                         struct persistent_ram_zone *tmp_prz, *prz_next;
 289
 290                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 291                                           GFP_KERNEL);
 292                         if (!tmp_prz)
 293                                 return -ENOMEM;
 294                         prz = tmp_prz;
 295                         free_prz = true;
 296
 297                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 298                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 299                                                 cxt->ftrace_read_cnt++, record);
 300
 301                                 if (!prz_ok(prz_next))
 302                                         continue;
 303
 304                                 tmp_prz->ecc_info = prz_next->ecc_info;
 305                                 tmp_prz->corrected_bytes +=
 306                                                 prz_next->corrected_bytes;
 307                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 308                                 size = ftrace_log_combine(tmp_prz, prz_next);
 309                                 if (size)
 310                                         goto out;
 311                         }
 312                         record->id = 0;
 313                 }
 314         }
 315
 316         if (!prz_ok(prz)) {
 317                 size = 0;
 318                 goto out;
 319         }
 320
 321         size = persistent_ram_old_size(prz) - header_length;
 322
 323         /* ECC correction notice */
 324         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 325
 326         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 327         if (record->buf == NULL) {
 328                 size = -ENOMEM;
 329                 goto out;
 330         }
 331
 332         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 333                size);
 334
 335         persistent_ram_ecc_string(prz, record->buf + size,
 336                                   record->ecc_notice_size + 1);
 337
 338 out:
 339         if (free_prz) {
 340                 kfree(prz->old_log);
 341                 kfree(prz);
 342         }
 343
 344         return size;
 345 }
 346
 347 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 348                                      struct pstore_record *record)
 349 {
 350         char *hdr;
 351         size_t len;
 352
 353         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
 354                 (time64_t)record->time.tv_sec,
 355                 record->time.tv_nsec / 1000,
 356                 record->compressed ? 'C' : 'D');
 357         WARN_ON_ONCE(!hdr);
 358         len = hdr ? strlen(hdr) : 0;
 359         persistent_ram_write(prz, hdr, len);
 360         kfree(hdr);
 361
 362         return len;
 363 }
 364
 365 static int notrace ramoops_pstore_write(struct pstore_record *record)
 366 {
 367         struct ramoops_context *cxt = record->psi->data;
 368         struct persistent_ram_zone *prz;
 369         size_t size, hlen;
 370
 371         if (record->type == PSTORE_TYPE_CONSOLE) {
 372                 if (!cxt->cprz)
 373                         return -ENOMEM;
 374                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 375                 return 0;
 376         } else if (record->type == PSTORE_TYPE_FTRACE) {
 377                 int zonenum;
 378
 379                 if (!cxt->fprzs)
 380                         return -ENOMEM;
 381                 /*
 382                  * Choose zone by if we're using per-cpu buffers.
 383                  */
 384                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 385                         zonenum = smp_processor_id();
 386                 else
 387                         zonenum = 0;
 388
 389                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 390                                      record->size);
 391                 return 0;
 392         } else if (record->type == PSTORE_TYPE_PMSG) {
 393                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 394                 return -EINVAL;
 395         }
 396
 397         if (record->type != PSTORE_TYPE_DMESG)
 398                 return -EINVAL;
 399
 400         /*
 401          * Out of the various dmesg dump types, ramoops is currently designed
 402          * to only store crash logs, rather than storing general kernel logs.
 403          */
 404         if (record->reason != KMSG_DUMP_OOPS &&
 405             record->reason != KMSG_DUMP_PANIC)
 406                 return -EINVAL;
 407
 408         /* Skip Oopes when configured to do so. */
 409         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 410                 return -EINVAL;
 411
 412         /*
 413          * Explicitly only take the first part of any new crash.
 414          * If our buffer is larger than kmsg_bytes, this can never happen,
 415          * and if our buffer is smaller than kmsg_bytes, we don't want the
 416          * report split across multiple records.
 417          */
 418         if (record->part != 1)
 419                 return -ENOSPC;
 420
 421         if (!cxt->dprzs)
 422                 return -ENOSPC;
 423
 424         prz = cxt->dprzs[cxt->dump_write_cnt];
 425
 426         /* Build header and append record contents. */
 427         hlen = ramoops_write_kmsg_hdr(prz, record);
 428         size = record->size;
 429         if (size + hlen > prz->buffer_size)
 430                 size = prz->buffer_size - hlen;
 431         persistent_ram_write(prz, record->buf, size);
 432
 433         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 434
 435         return 0;
 436 }
 437
 438 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 439                                              const char __user *buf)
 440 {
 441         if (record->type == PSTORE_TYPE_PMSG) {
 442                 struct ramoops_context *cxt = record->psi->data;
 443
 444                 if (!cxt->mprz)
 445                         return -ENOMEM;
 446                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 447         }
 448
 449         return -EINVAL;
 450 }
 451
 452 static int ramoops_pstore_erase(struct pstore_record *record)
 453 {
 454         struct ramoops_context *cxt = record->psi->data;
 455         struct persistent_ram_zone *prz;
 456
 457         switch (record->type) {
 458         case PSTORE_TYPE_DMESG:
 459                 if (record->id >= cxt->max_dump_cnt)
 460                         return -EINVAL;
 461                 prz = cxt->dprzs[record->id];
 462                 break;
 463         case PSTORE_TYPE_CONSOLE:
 464                 prz = cxt->cprz;
 465                 break;
 466         case PSTORE_TYPE_FTRACE:
 467                 if (record->id >= cxt->max_ftrace_cnt)
 468                         return -EINVAL;
 469                 prz = cxt->fprzs[record->id];
 470                 break;
 471         case PSTORE_TYPE_PMSG:
 472                 prz = cxt->mprz;
 473                 break;
 474         default:
 475                 return -EINVAL;
 476         }
 477
 478         persistent_ram_free_old(prz);
 479         persistent_ram_zap(prz);
 480
 481         return 0;
 482 }
 483
 484 static struct ramoops_context oops_cxt = {
 485         .pstore = {
 486                 .owner  = THIS_MODULE,
 487                 .name   = "ramoops",
 488                 .open   = ramoops_pstore_open,
 489                 .read   = ramoops_pstore_read,
 490                 .write  = ramoops_pstore_write,
 491                 .write_user     = ramoops_pstore_write_user,
 492                 .erase  = ramoops_pstore_erase,
 493         },
 494 };
 495
 496 static void ramoops_free_przs(struct ramoops_context *cxt)
 497 {
 498         int i;
 499
 500         /* Free dump PRZs */
 501         if (cxt->dprzs) {
 502                 for (i = 0; i < cxt->max_dump_cnt; i++)
 503                         persistent_ram_free(cxt->dprzs[i]);
 504
 505                 kfree(cxt->dprzs);
 506                 cxt->max_dump_cnt = 0;
 507         }
 508
 509         /* Free ftrace PRZs */
 510         if (cxt->fprzs) {
 511                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 512                         persistent_ram_free(cxt->fprzs[i]);
 513                 kfree(cxt->fprzs);
 514                 cxt->max_ftrace_cnt = 0;
 515         }
 516 }
 517
 518 static int ramoops_init_przs(const char *name,
 519                              struct device *dev, struct ramoops_context *cxt,
 520                              struct persistent_ram_zone ***przs,
 521                              phys_addr_t *paddr, size_t mem_sz,
 522                              ssize_t record_size,
 523                              unsigned int *cnt, u32 sig, u32 flags)
 524 {
 525         int err = -ENOMEM;
 526         int i;
 527         size_t zone_sz;
 528         struct persistent_ram_zone **prz_ar;
 529
 530         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 531         if (mem_sz == 0 || record_size == 0) {
 532                 *cnt = 0;
 533                 return 0;
 534         }
 535
 536         /*
 537          * If we have a negative record size, calculate it based on
 538          * mem_sz / *cnt. If we have a positive record size, calculate
 539          * cnt from mem_sz / record_size.
 540          */
 541         if (record_size < 0) {
 542                 if (*cnt == 0)
 543                         return 0;
 544                 record_size = mem_sz / *cnt;
 545                 if (record_size == 0) {
 546                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 547                                 name, mem_sz, *cnt);
 548                         goto fail;
 549                 }
 550         } else {
 551                 *cnt = mem_sz / record_size;
 552                 if (*cnt == 0) {
 553                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 554                                 name, mem_sz, record_size);
 555                         goto fail;
 556                 }
 557         }
 558
 559         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 560                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 561                         name,
 562                         mem_sz, (unsigned long long)*paddr,
 563                         cxt->size, (unsigned long long)cxt->phys_addr);
 564                 goto fail;
 565         }
 566
 567         zone_sz = mem_sz / *cnt;
 568         if (!zone_sz) {
 569                 dev_err(dev, "%s zone size == 0\n", name);
 570                 goto fail;
 571         }
 572
 573         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 574         if (!prz_ar)
 575                 goto fail;
 576
 577         for (i = 0; i < *cnt; i++) {
 578                 char *label;
 579
 580                 if (*cnt == 1)
 581                         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 582                 else
 583                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
 584                                           name, i, *cnt - 1);
 585                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 586                                                &cxt->ecc_info,
 587                                                cxt->memtype, flags, label);
 588                 if (IS_ERR(prz_ar[i])) {
 589                         err = PTR_ERR(prz_ar[i]);
 590                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 591                                 name, record_size,
 592                                 (unsigned long long)*paddr, err);
 593
 594                         while (i > 0) {
 595                                 i--;
 596                                 persistent_ram_free(prz_ar[i]);
 597                         }
 598                         kfree(prz_ar);
 599                         goto fail;
 600                 }
 601                 *paddr += zone_sz;
 602                 prz_ar[i]->type = pstore_name_to_type(name);
 603         }
 604
 605         *przs = prz_ar;
 606         return 0;
 607
 608 fail:
 609         *cnt = 0;
 610         return err;
 611 }
 612
 613 static int ramoops_init_prz(const char *name,
 614                             struct device *dev, struct ramoops_context *cxt,
 615                             struct persistent_ram_zone **prz,
 616                             phys_addr_t *paddr, size_t sz, u32 sig)
 617 {
 618         char *label;
 619
 620         if (!sz)
 621                 return 0;
 622
 623         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 624                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 625                         name, sz, (unsigned long long)*paddr,
 626                         cxt->size, (unsigned long long)cxt->phys_addr);
 627                 return -ENOMEM;
 628         }
 629
 630         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 631         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 632                                   cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
 633         if (IS_ERR(*prz)) {
 634                 int err = PTR_ERR(*prz);
 635
 636                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 637                         name, sz, (unsigned long long)*paddr, err);
 638                 return err;
 639         }
 640
 641         *paddr += sz;
 642         (*prz)->type = pstore_name_to_type(name);
 643
 644         return 0;
 645 }
 646
 647 static int ramoops_parse_dt_size(struct platform_device *pdev,
 648                                  const char *propname, u32 *value)
 649 {
 650         u32 val32 = 0;
 651         int ret;
 652
 653         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 654         if (ret < 0 && ret != -EINVAL) {
 655                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 656                         propname, ret);
 657                 return ret;
 658         }
 659
 660         if (val32 > INT_MAX) {
 661                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 662                 return -EOVERFLOW;
 663         }
 664
 665         *value = val32;
 666         return 0;
 667 }
 668
 669 static int ramoops_parse_dt(struct platform_device *pdev,
 670                             struct ramoops_platform_data *pdata)
 671 {
 672         struct device_node *of_node = pdev->dev.of_node;
 673         struct resource *res;
 674         u32 value;
 675         int ret;
 676
 677         dev_dbg(&pdev->dev, "using Device Tree\n");
 678
 679         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 680         if (!res) {
 681                 dev_err(&pdev->dev,
 682                         "failed to locate DT /reserved-memory resource\n");
 683                 return -EINVAL;
 684         }
 685
 686         pdata->mem_size = resource_size(res);
 687         pdata->mem_address = res->start;
 688         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 689         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 690
 691 #define parse_size(name, field) {                                       \
 692                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 693                 if (ret < 0)                                            \
 694                         return ret;                                     \
 695                 field = value;                                          \
 696         }
 697
 698         parse_size("record-size", pdata->record_size);
 699         parse_size("console-size", pdata->console_size);
 700         parse_size("ftrace-size", pdata->ftrace_size);
 701         parse_size("pmsg-size", pdata->pmsg_size);
 702         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 703         parse_size("flags", pdata->flags);
 704
 705 #undef parse_size
 706
 707         return 0;
 708 }
 709
 710 static int ramoops_probe(struct platform_device *pdev)
 711 {
 712         struct device *dev = &pdev->dev;
 713         struct ramoops_platform_data *pdata = dev->platform_data;
 714         struct ramoops_context *cxt = &oops_cxt;
 715         size_t dump_mem_sz;
 716         phys_addr_t paddr;
 717         int err = -EINVAL;
 718
 719         if (dev_of_node(dev) && !pdata) {
 720                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 721                 if (!pdata) {
 722                         pr_err("cannot allocate platform data buffer\n");
 723                         err = -ENOMEM;
 724                         goto fail_out;
 725                 }
 726
 727                 err = ramoops_parse_dt(pdev, pdata);
 728                 if (err < 0)
 729                         goto fail_out;
 730         }
 731
 732         /*
 733          * Only a single ramoops area allowed at a time, so fail extra
 734          * probes.
 735          */
 736         if (cxt->max_dump_cnt) {
 737                 pr_err("already initialized\n");
 738                 goto fail_out;
 739         }
 740
 741         /* Make sure we didn't get bogus platform data pointer. */
 742         if (!pdata) {
 743                 pr_err("NULL platform data\n");
 744                 goto fail_out;
 745         }
 746
 747         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 748                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 749                 pr_err("The memory size and the record/console size must be "
 750                         "non-zero\n");
 751                 goto fail_out;
 752         }
 753
 754         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 755                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 756         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 757                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 758         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 759                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 760         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 761                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 762
 763         cxt->size = pdata->mem_size;
 764         cxt->phys_addr = pdata->mem_address;
 765         cxt->memtype = pdata->mem_type;
 766         cxt->record_size = pdata->record_size;
 767         cxt->console_size = pdata->console_size;
 768         cxt->ftrace_size = pdata->ftrace_size;
 769         cxt->pmsg_size = pdata->pmsg_size;
 770         cxt->dump_oops = pdata->dump_oops;
 771         cxt->flags = pdata->flags;
 772         cxt->ecc_info = pdata->ecc_info;
 773
 774         paddr = cxt->phys_addr;
 775
 776         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 777                         - cxt->pmsg_size;
 778         err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
 779                                 dump_mem_sz, cxt->record_size,
 780                                 &cxt->max_dump_cnt, 0, 0);
 781         if (err)
 782                 goto fail_out;
 783
 784         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 785                                cxt->console_size, 0);
 786         if (err)
 787                 goto fail_init_cprz;
 788
 789         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 790                                 ? nr_cpu_ids
 791                                 : 1;
 792         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 793                                 cxt->ftrace_size, -1,
 794                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 795                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 796                                         ? PRZ_FLAG_NO_LOCK : 0);
 797         if (err)
 798                 goto fail_init_fprz;
 799
 800         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 801                                 cxt->pmsg_size, 0);
 802         if (err)
 803                 goto fail_init_mprz;
 804
 805         cxt->pstore.data = cxt;
 806         /*
 807          * Since bufsize is only used for dmesg crash dumps, it
 808          * must match the size of the dprz record (after PRZ header
 809          * and ECC bytes have been accounted for).
 810          */
 811         cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
 812         cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
 813         if (!cxt->pstore.buf) {
 814                 pr_err("cannot allocate pstore crash dump buffer\n");
 815                 err = -ENOMEM;
 816                 goto fail_clear;
 817         }
 818
 819         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 820         if (cxt->console_size)
 821                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 822         if (cxt->ftrace_size)
 823                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 824         if (cxt->pmsg_size)
 825                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 826
 827         err = pstore_register(&cxt->pstore);
 828         if (err) {
 829                 pr_err("registering with pstore failed\n");
 830                 goto fail_buf;
 831         }
 832
 833         /*
 834          * Update the module parameter variables as well so they are visible
 835          * through /sys/module/ramoops/parameters/
 836          */
 837         mem_size = pdata->mem_size;
 838         mem_address = pdata->mem_address;
 839         record_size = pdata->record_size;
 840         dump_oops = pdata->dump_oops;
 841         ramoops_console_size = pdata->console_size;
 842         ramoops_pmsg_size = pdata->pmsg_size;
 843         ramoops_ftrace_size = pdata->ftrace_size;
 844
 845         pr_info("using 0x%lx@0x%llx, ecc: %d\n",
 846                 cxt->size, (unsigned long long)cxt->phys_addr,
 847                 cxt->ecc_info.ecc_size);
 848
 849         return 0;
 850
 851 fail_buf:
 852         kfree(cxt->pstore.buf);
 853 fail_clear:
 854         cxt->pstore.bufsize = 0;
 855         persistent_ram_free(cxt->mprz);
 856 fail_init_mprz:
 857 fail_init_fprz:
 858         persistent_ram_free(cxt->cprz);
 859 fail_init_cprz:
 860         ramoops_free_przs(cxt);
 861 fail_out:
 862         return err;
 863 }
 864
 865 static int ramoops_remove(struct platform_device *pdev)
 866 {
 867         struct ramoops_context *cxt = &oops_cxt;
 868
 869         pstore_unregister(&cxt->pstore);
 870
 871         kfree(cxt->pstore.buf);
 872         cxt->pstore.bufsize = 0;
 873
 874         persistent_ram_free(cxt->mprz);
 875         persistent_ram_free(cxt->cprz);
 876         ramoops_free_przs(cxt);
 877
 878         return 0;
 879 }
 880
 881 static const struct of_device_id dt_match[] = {
 882         { .compatible = "ramoops" },
 883         {}
 884 };
 885
 886 static struct platform_driver ramoops_driver = {
 887         .probe          = ramoops_probe,
 888         .remove         = ramoops_remove,
 889         .driver         = {
 890                 .name           = "ramoops",
 891                 .of_match_table = dt_match,
 892         },
 893 };
 894
 895 static inline void ramoops_unregister_dummy(void)
 896 {
 897         platform_device_unregister(dummy);
 898         dummy = NULL;
 899
 900         kfree(dummy_data);
 901         dummy_data = NULL;
 902 }
 903
 904 static void __init ramoops_register_dummy(void)
 905 {
 906         /*
 907          * Prepare a dummy platform data structure to carry the module
 908          * parameters. If mem_size isn't set, then there are no module
 909          * parameters, and we can skip this.
 910          */
 911         if (!mem_size)
 912                 return;
 913
 914         pr_info("using module parameters\n");
 915
 916         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 917         if (!dummy_data) {
 918                 pr_info("could not allocate pdata\n");
 919                 return;
 920         }
 921
 922         dummy_data->mem_size = mem_size;
 923         dummy_data->mem_address = mem_address;
 924         dummy_data->mem_type = mem_type;
 925         dummy_data->record_size = record_size;
 926         dummy_data->console_size = ramoops_console_size;
 927         dummy_data->ftrace_size = ramoops_ftrace_size;
 928         dummy_data->pmsg_size = ramoops_pmsg_size;
 929         dummy_data->dump_oops = dump_oops;
 930         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 931
 932         /*
 933          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 934          * (using 1 byte for ECC isn't much of use anyway).
 935          */
 936         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 937
 938         dummy = platform_device_register_data(NULL, "ramoops", -1,
 939                         dummy_data, sizeof(struct ramoops_platform_data));
 940         if (IS_ERR(dummy)) {
 941                 pr_info("could not create platform device: %ld\n",
 942                         PTR_ERR(dummy));
 943                 dummy = NULL;
 944                 ramoops_unregister_dummy();
 945         }
 946 }
 947
 948 static int __init ramoops_init(void)
 949 {
 950         int ret;
 951
 952         ramoops_register_dummy();
 953         ret = platform_driver_register(&ramoops_driver);
 954         if (ret != 0)
 955                 ramoops_unregister_dummy();
 956
 957         return ret;
 958 }
 959 postcore_initcall(ramoops_init);
 960
 961 static void __exit ramoops_exit(void)
 962 {
 963         platform_driver_unregister(&ramoops_driver);
 964         ramoops_unregister_dummy();
 965 }
 966 module_exit(ramoops_exit);
 967
 968 MODULE_LICENSE("GPL");
 969 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 970 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");