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
 114 static int ramoops_pstore_open(struct pstore_info *psi)
 115 {
 116         struct ramoops_context *cxt = psi->data;
 117
 118         cxt->dump_read_cnt = 0;
 119         cxt->console_read_cnt = 0;
 120         cxt->ftrace_read_cnt = 0;
 121         cxt->pmsg_read_cnt = 0;
 122         return 0;
 123 }
 124
 125 static struct persistent_ram_zone *
 126 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
 127                      struct pstore_record *record)
 128 {
 129         struct persistent_ram_zone *prz;
 130
 131         /* Give up if we never existed or have hit the end. */
 132         if (!przs)
 133                 return NULL;
 134
 135         prz = przs[id];
 136         if (!prz)
 137                 return NULL;
 138
 139         /* Update old/shadowed buffer. */
 140         if (prz->type == PSTORE_TYPE_DMESG)
 141                 persistent_ram_save_old(prz);
 142
 143         if (!persistent_ram_old_size(prz))
 144                 return NULL;
 145
 146         record->type = prz->type;
 147         record->id = id;
 148
 149         return prz;
 150 }
 151
 152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
 153                                   bool *compressed)
 154 {
 155         char data_type;
 156         int header_length = 0;
 157
 158         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
 159                    (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
 160                    &header_length) == 3) {
 161                 if (data_type == 'C')
 162                         *compressed = true;
 163                 else
 164                         *compressed = false;
 165         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 166                           (time64_t *)&time->tv_sec, &time->tv_nsec,
 167                           &header_length) == 2) {
 168                 *compressed = false;
 169         } else {
 170                 time->tv_sec = 0;
 171                 time->tv_nsec = 0;
 172                 *compressed = false;
 173         }
 174         return header_length;
 175 }
 176
 177 static bool prz_ok(struct persistent_ram_zone *prz)
 178 {
 179         return !!prz && !!(persistent_ram_old_size(prz) +
 180                            persistent_ram_ecc_string(prz, NULL, 0));
 181 }
 182
 183 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 184                                   struct persistent_ram_zone *src)
 185 {
 186         size_t dest_size, src_size, total, dest_off, src_off;
 187         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 188         void *merged_buf;
 189         struct pstore_ftrace_record *drec, *srec, *mrec;
 190         size_t record_size = sizeof(struct pstore_ftrace_record);
 191
 192         dest_off = dest->old_log_size % record_size;
 193         dest_size = dest->old_log_size - dest_off;
 194
 195         src_off = src->old_log_size % record_size;
 196         src_size = src->old_log_size - src_off;
 197
 198         total = dest_size + src_size;
 199         merged_buf = kmalloc(total, GFP_KERNEL);
 200         if (!merged_buf)
 201                 return -ENOMEM;
 202
 203         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 204         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 205         mrec = (struct pstore_ftrace_record *)(merged_buf);
 206
 207         while (dest_size > 0 && src_size > 0) {
 208                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 209                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 210                         mrec[merged_idx++] = drec[dest_idx++];
 211                         dest_size -= record_size;
 212                 } else {
 213                         mrec[merged_idx++] = srec[src_idx++];
 214                         src_size -= record_size;
 215                 }
 216         }
 217
 218         while (dest_size > 0) {
 219                 mrec[merged_idx++] = drec[dest_idx++];
 220                 dest_size -= record_size;
 221         }
 222
 223         while (src_size > 0) {
 224                 mrec[merged_idx++] = srec[src_idx++];
 225                 src_size -= record_size;
 226         }
 227
 228         kfree(dest->old_log);
 229         dest->old_log = merged_buf;
 230         dest->old_log_size = total;
 231
 232         return 0;
 233 }
 234
 235 static ssize_t ramoops_pstore_read(struct pstore_record *record)
 236 {
 237         ssize_t size = 0;
 238         struct ramoops_context *cxt = record->psi->data;
 239         struct persistent_ram_zone *prz = NULL;
 240         int header_length = 0;
 241         bool free_prz = false;
 242
 243         /*
 244          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 245          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 246          * valid time stamps, so it is initialized to zero.
 247          */
 248         record->time.tv_sec = 0;
 249         record->time.tv_nsec = 0;
 250         record->compressed = false;
 251
 252         /* Find the next valid persistent_ram_zone for DMESG */
 253         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 254                 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
 255                                            record);
 256                 if (!prz_ok(prz))
 257                         continue;
 258                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 259                                                       &record->time,
 260                                                       &record->compressed);
 261                 /* Clear and skip this DMESG record if it has no valid header */
 262                 if (!header_length) {
 263                         persistent_ram_free_old(prz);
 264                         persistent_ram_zap(prz);
 265                         prz = NULL;
 266                 }
 267         }
 268
 269         if (!prz_ok(prz) && !cxt->console_read_cnt++)
 270                 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
 271
 272         if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
 273                 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
 274
 275         /* ftrace is last since it may want to dynamically allocate memory. */
 276         if (!prz_ok(prz)) {
 277                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
 278                     !cxt->ftrace_read_cnt++) {
 279                         prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
 280                                                    record);
 281                 } else {
 282                         /*
 283                          * Build a new dummy record which combines all the
 284                          * per-cpu records including metadata and ecc info.
 285                          */
 286                         struct persistent_ram_zone *tmp_prz, *prz_next;
 287
 288                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 289                                           GFP_KERNEL);
 290                         if (!tmp_prz)
 291                                 return -ENOMEM;
 292                         prz = tmp_prz;
 293                         free_prz = true;
 294
 295                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 296                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 297                                                 cxt->ftrace_read_cnt++, record);
 298
 299                                 if (!prz_ok(prz_next))
 300                                         continue;
 301
 302                                 tmp_prz->ecc_info = prz_next->ecc_info;
 303                                 tmp_prz->corrected_bytes +=
 304                                                 prz_next->corrected_bytes;
 305                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 306                                 size = ftrace_log_combine(tmp_prz, prz_next);
 307                                 if (size)
 308                                         goto out;
 309                         }
 310                         record->id = 0;
 311                 }
 312         }
 313
 314         if (!prz_ok(prz)) {
 315                 size = 0;
 316                 goto out;
 317         }
 318
 319         size = persistent_ram_old_size(prz) - header_length;
 320
 321         /* ECC correction notice */
 322         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 323
 324         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 325         if (record->buf == NULL) {
 326                 size = -ENOMEM;
 327                 goto out;
 328         }
 329
 330         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 331                size);
 332
 333         persistent_ram_ecc_string(prz, record->buf + size,
 334                                   record->ecc_notice_size + 1);
 335
 336 out:
 337         if (free_prz) {
 338                 kfree(prz->old_log);
 339                 kfree(prz);
 340         }
 341
 342         return size;
 343 }
 344
 345 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 346                                      struct pstore_record *record)
 347 {
 348         char *hdr;
 349         size_t len;
 350
 351         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
 352                 (time64_t)record->time.tv_sec,
 353                 record->time.tv_nsec / 1000,
 354                 record->compressed ? 'C' : 'D');
 355         WARN_ON_ONCE(!hdr);
 356         len = hdr ? strlen(hdr) : 0;
 357         persistent_ram_write(prz, hdr, len);
 358         kfree(hdr);
 359
 360         return len;
 361 }
 362
 363 static int notrace ramoops_pstore_write(struct pstore_record *record)
 364 {
 365         struct ramoops_context *cxt = record->psi->data;
 366         struct persistent_ram_zone *prz;
 367         size_t size, hlen;
 368
 369         if (record->type == PSTORE_TYPE_CONSOLE) {
 370                 if (!cxt->cprz)
 371                         return -ENOMEM;
 372                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 373                 return 0;
 374         } else if (record->type == PSTORE_TYPE_FTRACE) {
 375                 int zonenum;
 376
 377                 if (!cxt->fprzs)
 378                         return -ENOMEM;
 379                 /*
 380                  * Choose zone by if we're using per-cpu buffers.
 381                  */
 382                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 383                         zonenum = smp_processor_id();
 384                 else
 385                         zonenum = 0;
 386
 387                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 388                                      record->size);
 389                 return 0;
 390         } else if (record->type == PSTORE_TYPE_PMSG) {
 391                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 392                 return -EINVAL;
 393         }
 394
 395         if (record->type != PSTORE_TYPE_DMESG)
 396                 return -EINVAL;
 397
 398         /*
 399          * Out of the various dmesg dump types, ramoops is currently designed
 400          * to only store crash logs, rather than storing general kernel logs.
 401          */
 402         if (record->reason != KMSG_DUMP_OOPS &&
 403             record->reason != KMSG_DUMP_PANIC)
 404                 return -EINVAL;
 405
 406         /* Skip Oopes when configured to do so. */
 407         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 408                 return -EINVAL;
 409
 410         /*
 411          * Explicitly only take the first part of any new crash.
 412          * If our buffer is larger than kmsg_bytes, this can never happen,
 413          * and if our buffer is smaller than kmsg_bytes, we don't want the
 414          * report split across multiple records.
 415          */
 416         if (record->part != 1)
 417                 return -ENOSPC;
 418
 419         if (!cxt->dprzs)
 420                 return -ENOSPC;
 421
 422         prz = cxt->dprzs[cxt->dump_write_cnt];
 423
 424         /* Build header and append record contents. */
 425         hlen = ramoops_write_kmsg_hdr(prz, record);
 426         size = record->size;
 427         if (size + hlen > prz->buffer_size)
 428                 size = prz->buffer_size - hlen;
 429         persistent_ram_write(prz, record->buf, size);
 430
 431         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 432
 433         return 0;
 434 }
 435
 436 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 437                                              const char __user *buf)
 438 {
 439         if (record->type == PSTORE_TYPE_PMSG) {
 440                 struct ramoops_context *cxt = record->psi->data;
 441
 442                 if (!cxt->mprz)
 443                         return -ENOMEM;
 444                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 445         }
 446
 447         return -EINVAL;
 448 }
 449
 450 static int ramoops_pstore_erase(struct pstore_record *record)
 451 {
 452         struct ramoops_context *cxt = record->psi->data;
 453         struct persistent_ram_zone *prz;
 454
 455         switch (record->type) {
 456         case PSTORE_TYPE_DMESG:
 457                 if (record->id >= cxt->max_dump_cnt)
 458                         return -EINVAL;
 459                 prz = cxt->dprzs[record->id];
 460                 break;
 461         case PSTORE_TYPE_CONSOLE:
 462                 prz = cxt->cprz;
 463                 break;
 464         case PSTORE_TYPE_FTRACE:
 465                 if (record->id >= cxt->max_ftrace_cnt)
 466                         return -EINVAL;
 467                 prz = cxt->fprzs[record->id];
 468                 break;
 469         case PSTORE_TYPE_PMSG:
 470                 prz = cxt->mprz;
 471                 break;
 472         default:
 473                 return -EINVAL;
 474         }
 475
 476         persistent_ram_free_old(prz);
 477         persistent_ram_zap(prz);
 478
 479         return 0;
 480 }
 481
 482 static struct ramoops_context oops_cxt = {
 483         .pstore = {
 484                 .owner  = THIS_MODULE,
 485                 .name   = "ramoops",
 486                 .open   = ramoops_pstore_open,
 487                 .read   = ramoops_pstore_read,
 488                 .write  = ramoops_pstore_write,
 489                 .write_user     = ramoops_pstore_write_user,
 490                 .erase  = ramoops_pstore_erase,
 491         },
 492 };
 493
 494 static void ramoops_free_przs(struct ramoops_context *cxt)
 495 {
 496         int i;
 497
 498         /* Free dump PRZs */
 499         if (cxt->dprzs) {
 500                 for (i = 0; i < cxt->max_dump_cnt; i++)
 501                         persistent_ram_free(cxt->dprzs[i]);
 502
 503                 kfree(cxt->dprzs);
 504                 cxt->max_dump_cnt = 0;
 505         }
 506
 507         /* Free ftrace PRZs */
 508         if (cxt->fprzs) {
 509                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 510                         persistent_ram_free(cxt->fprzs[i]);
 511                 kfree(cxt->fprzs);
 512                 cxt->max_ftrace_cnt = 0;
 513         }
 514 }
 515
 516 static int ramoops_init_przs(const char *name,
 517                              struct device *dev, struct ramoops_context *cxt,
 518                              struct persistent_ram_zone ***przs,
 519                              phys_addr_t *paddr, size_t mem_sz,
 520                              ssize_t record_size,
 521                              unsigned int *cnt, u32 sig, u32 flags)
 522 {
 523         int err = -ENOMEM;
 524         int i;
 525         size_t zone_sz;
 526         struct persistent_ram_zone **prz_ar;
 527
 528         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 529         if (mem_sz == 0 || record_size == 0) {
 530                 *cnt = 0;
 531                 return 0;
 532         }
 533
 534         /*
 535          * If we have a negative record size, calculate it based on
 536          * mem_sz / *cnt. If we have a positive record size, calculate
 537          * cnt from mem_sz / record_size.
 538          */
 539         if (record_size < 0) {
 540                 if (*cnt == 0)
 541                         return 0;
 542                 record_size = mem_sz / *cnt;
 543                 if (record_size == 0) {
 544                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 545                                 name, mem_sz, *cnt);
 546                         goto fail;
 547                 }
 548         } else {
 549                 *cnt = mem_sz / record_size;
 550                 if (*cnt == 0) {
 551                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 552                                 name, mem_sz, record_size);
 553                         goto fail;
 554                 }
 555         }
 556
 557         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 558                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 559                         name,
 560                         mem_sz, (unsigned long long)*paddr,
 561                         cxt->size, (unsigned long long)cxt->phys_addr);
 562                 goto fail;
 563         }
 564
 565         zone_sz = mem_sz / *cnt;
 566         if (!zone_sz) {
 567                 dev_err(dev, "%s zone size == 0\n", name);
 568                 goto fail;
 569         }
 570
 571         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 572         if (!prz_ar)
 573                 goto fail;
 574
 575         for (i = 0; i < *cnt; i++) {
 576                 char *label;
 577
 578                 if (*cnt == 1)
 579                         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 580                 else
 581                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
 582                                           name, i, *cnt - 1);
 583                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 584                                                &cxt->ecc_info,
 585                                                cxt->memtype, flags, label);
 586                 if (IS_ERR(prz_ar[i])) {
 587                         err = PTR_ERR(prz_ar[i]);
 588                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 589                                 name, record_size,
 590                                 (unsigned long long)*paddr, err);
 591
 592                         while (i > 0) {
 593                                 i--;
 594                                 persistent_ram_free(prz_ar[i]);
 595                         }
 596                         kfree(prz_ar);
 597                         goto fail;
 598                 }
 599                 *paddr += zone_sz;
 600                 prz_ar[i]->type = pstore_name_to_type(name);
 601         }
 602
 603         *przs = prz_ar;
 604         return 0;
 605
 606 fail:
 607         *cnt = 0;
 608         return err;
 609 }
 610
 611 static int ramoops_init_prz(const char *name,
 612                             struct device *dev, struct ramoops_context *cxt,
 613                             struct persistent_ram_zone **prz,
 614                             phys_addr_t *paddr, size_t sz, u32 sig)
 615 {
 616         char *label;
 617
 618         if (!sz)
 619                 return 0;
 620
 621         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 622                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 623                         name, sz, (unsigned long long)*paddr,
 624                         cxt->size, (unsigned long long)cxt->phys_addr);
 625                 return -ENOMEM;
 626         }
 627
 628         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 629         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 630                                   cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
 631         if (IS_ERR(*prz)) {
 632                 int err = PTR_ERR(*prz);
 633
 634                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 635                         name, sz, (unsigned long long)*paddr, err);
 636                 return err;
 637         }
 638
 639         *paddr += sz;
 640         (*prz)->type = pstore_name_to_type(name);
 641
 642         return 0;
 643 }
 644
 645 static int ramoops_parse_dt_size(struct platform_device *pdev,
 646                                  const char *propname, u32 *value)
 647 {
 648         u32 val32 = 0;
 649         int ret;
 650
 651         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 652         if (ret < 0 && ret != -EINVAL) {
 653                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 654                         propname, ret);
 655                 return ret;
 656         }
 657
 658         if (val32 > INT_MAX) {
 659                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 660                 return -EOVERFLOW;
 661         }
 662
 663         *value = val32;
 664         return 0;
 665 }
 666
 667 static int ramoops_parse_dt(struct platform_device *pdev,
 668                             struct ramoops_platform_data *pdata)
 669 {
 670         struct device_node *of_node = pdev->dev.of_node;
 671         struct resource *res;
 672         u32 value;
 673         int ret;
 674
 675         dev_dbg(&pdev->dev, "using Device Tree\n");
 676
 677         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 678         if (!res) {
 679                 dev_err(&pdev->dev,
 680                         "failed to locate DT /reserved-memory resource\n");
 681                 return -EINVAL;
 682         }
 683
 684         pdata->mem_size = resource_size(res);
 685         pdata->mem_address = res->start;
 686         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 687         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 688
 689 #define parse_size(name, field) {                                       \
 690                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 691                 if (ret < 0)                                            \
 692                         return ret;                                     \
 693                 field = value;                                          \
 694         }
 695
 696         parse_size("record-size", pdata->record_size);
 697         parse_size("console-size", pdata->console_size);
 698         parse_size("ftrace-size", pdata->ftrace_size);
 699         parse_size("pmsg-size", pdata->pmsg_size);
 700         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 701         parse_size("flags", pdata->flags);
 702
 703 #undef parse_size
 704
 705         return 0;
 706 }
 707
 708 static int ramoops_probe(struct platform_device *pdev)
 709 {
 710         struct device *dev = &pdev->dev;
 711         struct ramoops_platform_data *pdata = dev->platform_data;
 712         struct ramoops_platform_data pdata_local;
 713         struct ramoops_context *cxt = &oops_cxt;
 714         size_t dump_mem_sz;
 715         phys_addr_t paddr;
 716         int err = -EINVAL;
 717
 718         if (dev_of_node(dev) && !pdata) {
 719                 pdata = &pdata_local;
 720                 memset(pdata, 0, sizeof(*pdata));
 721
 722                 err = ramoops_parse_dt(pdev, pdata);
 723                 if (err < 0)
 724                         goto fail_out;
 725         }
 726
 727         /*
 728          * Only a single ramoops area allowed at a time, so fail extra
 729          * probes.
 730          */
 731         if (cxt->max_dump_cnt) {
 732                 pr_err("already initialized\n");
 733                 goto fail_out;
 734         }
 735
 736         /* Make sure we didn't get bogus platform data pointer. */
 737         if (!pdata) {
 738                 pr_err("NULL platform data\n");
 739                 goto fail_out;
 740         }
 741
 742         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 743                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 744                 pr_err("The memory size and the record/console size must be "
 745                         "non-zero\n");
 746                 goto fail_out;
 747         }
 748
 749         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 750                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 751         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 752                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 753         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 754                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 755         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 756                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 757
 758         cxt->size = pdata->mem_size;
 759         cxt->phys_addr = pdata->mem_address;
 760         cxt->memtype = pdata->mem_type;
 761         cxt->record_size = pdata->record_size;
 762         cxt->console_size = pdata->console_size;
 763         cxt->ftrace_size = pdata->ftrace_size;
 764         cxt->pmsg_size = pdata->pmsg_size;
 765         cxt->dump_oops = pdata->dump_oops;
 766         cxt->flags = pdata->flags;
 767         cxt->ecc_info = pdata->ecc_info;
 768
 769         paddr = cxt->phys_addr;
 770
 771         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 772                         - cxt->pmsg_size;
 773         err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
 774                                 dump_mem_sz, cxt->record_size,
 775                                 &cxt->max_dump_cnt, 0, 0);
 776         if (err)
 777                 goto fail_out;
 778
 779         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 780                                cxt->console_size, 0);
 781         if (err)
 782                 goto fail_init_cprz;
 783
 784         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 785                                 ? nr_cpu_ids
 786                                 : 1;
 787         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 788                                 cxt->ftrace_size, -1,
 789                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 790                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 791                                         ? PRZ_FLAG_NO_LOCK : 0);
 792         if (err)
 793                 goto fail_init_fprz;
 794
 795         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 796                                 cxt->pmsg_size, 0);
 797         if (err)
 798                 goto fail_init_mprz;
 799
 800         cxt->pstore.data = cxt;
 801         /*
 802          * Since bufsize is only used for dmesg crash dumps, it
 803          * must match the size of the dprz record (after PRZ header
 804          * and ECC bytes have been accounted for).
 805          */
 806         cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
 807         cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
 808         if (!cxt->pstore.buf) {
 809                 pr_err("cannot allocate pstore crash dump buffer\n");
 810                 err = -ENOMEM;
 811                 goto fail_clear;
 812         }
 813
 814         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 815         if (cxt->console_size)
 816                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 817         if (cxt->ftrace_size)
 818                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 819         if (cxt->pmsg_size)
 820                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 821
 822         err = pstore_register(&cxt->pstore);
 823         if (err) {
 824                 pr_err("registering with pstore failed\n");
 825                 goto fail_buf;
 826         }
 827
 828         /*
 829          * Update the module parameter variables as well so they are visible
 830          * through /sys/module/ramoops/parameters/
 831          */
 832         mem_size = pdata->mem_size;
 833         mem_address = pdata->mem_address;
 834         record_size = pdata->record_size;
 835         dump_oops = pdata->dump_oops;
 836         ramoops_console_size = pdata->console_size;
 837         ramoops_pmsg_size = pdata->pmsg_size;
 838         ramoops_ftrace_size = pdata->ftrace_size;
 839
 840         pr_info("using 0x%lx@0x%llx, ecc: %d\n",
 841                 cxt->size, (unsigned long long)cxt->phys_addr,
 842                 cxt->ecc_info.ecc_size);
 843
 844         return 0;
 845
 846 fail_buf:
 847         kfree(cxt->pstore.buf);
 848 fail_clear:
 849         cxt->pstore.bufsize = 0;
 850         persistent_ram_free(cxt->mprz);
 851 fail_init_mprz:
 852 fail_init_fprz:
 853         persistent_ram_free(cxt->cprz);
 854 fail_init_cprz:
 855         ramoops_free_przs(cxt);
 856 fail_out:
 857         return err;
 858 }
 859
 860 static int ramoops_remove(struct platform_device *pdev)
 861 {
 862         struct ramoops_context *cxt = &oops_cxt;
 863
 864         pstore_unregister(&cxt->pstore);
 865
 866         kfree(cxt->pstore.buf);
 867         cxt->pstore.bufsize = 0;
 868
 869         persistent_ram_free(cxt->mprz);
 870         persistent_ram_free(cxt->cprz);
 871         ramoops_free_przs(cxt);
 872
 873         return 0;
 874 }
 875
 876 static const struct of_device_id dt_match[] = {
 877         { .compatible = "ramoops" },
 878         {}
 879 };
 880
 881 static struct platform_driver ramoops_driver = {
 882         .probe          = ramoops_probe,
 883         .remove         = ramoops_remove,
 884         .driver         = {
 885                 .name           = "ramoops",
 886                 .of_match_table = dt_match,
 887         },
 888 };
 889
 890 static inline void ramoops_unregister_dummy(void)
 891 {
 892         platform_device_unregister(dummy);
 893         dummy = NULL;
 894 }
 895
 896 static void __init ramoops_register_dummy(void)
 897 {
 898         struct ramoops_platform_data pdata;
 899
 900         /*
 901          * Prepare a dummy platform data structure to carry the module
 902          * parameters. If mem_size isn't set, then there are no module
 903          * parameters, and we can skip this.
 904          */
 905         if (!mem_size)
 906                 return;
 907
 908         pr_info("using module parameters\n");
 909
 910         memset(&pdata, 0, sizeof(pdata));
 911         pdata.mem_size = mem_size;
 912         pdata.mem_address = mem_address;
 913         pdata.mem_type = mem_type;
 914         pdata.record_size = record_size;
 915         pdata.console_size = ramoops_console_size;
 916         pdata.ftrace_size = ramoops_ftrace_size;
 917         pdata.pmsg_size = ramoops_pmsg_size;
 918         pdata.dump_oops = dump_oops;
 919         pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 920
 921         /*
 922          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 923          * (using 1 byte for ECC isn't much of use anyway).
 924          */
 925         pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 926
 927         dummy = platform_device_register_data(NULL, "ramoops", -1,
 928                         &pdata, sizeof(pdata));
 929         if (IS_ERR(dummy)) {
 930                 pr_info("could not create platform device: %ld\n",
 931                         PTR_ERR(dummy));
 932                 dummy = NULL;
 933                 ramoops_unregister_dummy();
 934         }
 935 }
 936
 937 static int __init ramoops_init(void)
 938 {
 939         int ret;
 940
 941         ramoops_register_dummy();
 942         ret = platform_driver_register(&ramoops_driver);
 943         if (ret != 0)
 944                 ramoops_unregister_dummy();
 945
 946         return ret;
 947 }
 948 postcore_initcall(ramoops_init);
 949
 950 static void __exit ramoops_exit(void)
 951 {
 952         platform_driver_unregister(&ramoops_driver);
 953         ramoops_unregister_dummy();
 954 }
 955 module_exit(ramoops_exit);
 956
 957 MODULE_LICENSE("GPL");
 958 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 959 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");