fs/pstore/ram.c

   1 /*
   2  * RAM Oops/Panic logger
   3  *
   4  * Copyright (C) 2010 Marco Stornelli <[email protected]>
   5  * Copyright (C) 2011 Kees Cook <[email protected]>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/kernel.h>
  26 #include <linux/err.h>
  27 #include <linux/module.h>
  28 #include <linux/version.h>
  29 #include <linux/pstore.h>
  30 #include <linux/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                 if (data_type == 'C')
 166                         *compressed = true;
 167                 else
 168                         *compressed = false;
 169         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 170                           (time64_t *)&time->tv_sec, &time->tv_nsec,
 171                           &header_length) == 2) {
 172                 *compressed = false;
 173         } else {
 174                 time->tv_sec = 0;
 175                 time->tv_nsec = 0;
 176                 *compressed = false;
 177         }
 178         return header_length;
 179 }
 180
 181 static bool prz_ok(struct persistent_ram_zone *prz)
 182 {
 183         return !!prz && !!(persistent_ram_old_size(prz) +
 184                            persistent_ram_ecc_string(prz, NULL, 0));
 185 }
 186
 187 static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
 188                                   struct persistent_ram_zone *src)
 189 {
 190         size_t dest_size, src_size, total, dest_off, src_off;
 191         size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
 192         void *merged_buf;
 193         struct pstore_ftrace_record *drec, *srec, *mrec;
 194         size_t record_size = sizeof(struct pstore_ftrace_record);
 195
 196         dest_off = dest->old_log_size % record_size;
 197         dest_size = dest->old_log_size - dest_off;
 198
 199         src_off = src->old_log_size % record_size;
 200         src_size = src->old_log_size - src_off;
 201
 202         total = dest_size + src_size;
 203         merged_buf = kmalloc(total, GFP_KERNEL);
 204         if (!merged_buf)
 205                 return -ENOMEM;
 206
 207         drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
 208         srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
 209         mrec = (struct pstore_ftrace_record *)(merged_buf);
 210
 211         while (dest_size > 0 && src_size > 0) {
 212                 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
 213                     pstore_ftrace_read_timestamp(&srec[src_idx])) {
 214                         mrec[merged_idx++] = drec[dest_idx++];
 215                         dest_size -= record_size;
 216                 } else {
 217                         mrec[merged_idx++] = srec[src_idx++];
 218                         src_size -= record_size;
 219                 }
 220         }
 221
 222         while (dest_size > 0) {
 223                 mrec[merged_idx++] = drec[dest_idx++];
 224                 dest_size -= record_size;
 225         }
 226
 227         while (src_size > 0) {
 228                 mrec[merged_idx++] = srec[src_idx++];
 229                 src_size -= record_size;
 230         }
 231
 232         kfree(dest->old_log);
 233         dest->old_log = merged_buf;
 234         dest->old_log_size = total;
 235
 236         return 0;
 237 }
 238
 239 static ssize_t ramoops_pstore_read(struct pstore_record *record)
 240 {
 241         ssize_t size = 0;
 242         struct ramoops_context *cxt = record->psi->data;
 243         struct persistent_ram_zone *prz = NULL;
 244         int header_length = 0;
 245         bool free_prz = false;
 246
 247         /*
 248          * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
 249          * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
 250          * valid time stamps, so it is initialized to zero.
 251          */
 252         record->time.tv_sec = 0;
 253         record->time.tv_nsec = 0;
 254         record->compressed = false;
 255
 256         /* Find the next valid persistent_ram_zone for DMESG */
 257         while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
 258                 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
 259                                            cxt->max_dump_cnt, &record->id,
 260                                            &record->type,
 261                                            PSTORE_TYPE_DMESG, 1);
 262                 if (!prz_ok(prz))
 263                         continue;
 264                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 265                                                       &record->time,
 266                                                       &record->compressed);
 267                 /* Clear and skip this DMESG record if it has no valid header */
 268                 if (!header_length) {
 269                         persistent_ram_free_old(prz);
 270                         persistent_ram_zap(prz);
 271                         prz = NULL;
 272                 }
 273         }
 274
 275         if (!prz_ok(prz))
 276                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 277                                            1, &record->id, &record->type,
 278                                            PSTORE_TYPE_CONSOLE, 0);
 279
 280         if (!prz_ok(prz))
 281                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 282                                            1, &record->id, &record->type,
 283                                            PSTORE_TYPE_PMSG, 0);
 284
 285         /* ftrace is last since it may want to dynamically allocate memory. */
 286         if (!prz_ok(prz)) {
 287                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
 288                         prz = ramoops_get_next_prz(cxt->fprzs,
 289                                         &cxt->ftrace_read_cnt, 1, &record->id,
 290                                         &record->type, PSTORE_TYPE_FTRACE, 0);
 291                 } else {
 292                         /*
 293                          * Build a new dummy record which combines all the
 294                          * per-cpu records including metadata and ecc info.
 295                          */
 296                         struct persistent_ram_zone *tmp_prz, *prz_next;
 297
 298                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 299                                           GFP_KERNEL);
 300                         if (!tmp_prz)
 301                                 return -ENOMEM;
 302                         free_prz = true;
 303
 304                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 305                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 306                                                 &cxt->ftrace_read_cnt,
 307                                                 cxt->max_ftrace_cnt,
 308                                                 &record->id,
 309                                                 &record->type,
 310                                                 PSTORE_TYPE_FTRACE, 0);
 311
 312                                 if (!prz_ok(prz_next))
 313                                         continue;
 314
 315                                 tmp_prz->ecc_info = prz_next->ecc_info;
 316                                 tmp_prz->corrected_bytes +=
 317                                                 prz_next->corrected_bytes;
 318                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 319                                 size = ftrace_log_combine(tmp_prz, prz_next);
 320                                 if (size)
 321                                         goto out;
 322                         }
 323                         record->id = 0;
 324                         prz = tmp_prz;
 325                 }
 326         }
 327
 328         if (!prz_ok(prz)) {
 329                 size = 0;
 330                 goto out;
 331         }
 332
 333         size = persistent_ram_old_size(prz) - header_length;
 334
 335         /* ECC correction notice */
 336         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 337
 338         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 339         if (record->buf == NULL) {
 340                 size = -ENOMEM;
 341                 goto out;
 342         }
 343
 344         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 345                size);
 346
 347         persistent_ram_ecc_string(prz, record->buf + size,
 348                                   record->ecc_notice_size + 1);
 349
 350 out:
 351         if (free_prz) {
 352                 kfree(prz->old_log);
 353                 kfree(prz);
 354         }
 355
 356         return size;
 357 }
 358
 359 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 360                                      struct pstore_record *record)
 361 {
 362         char *hdr;
 363         size_t len;
 364
 365         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
 366                 (time64_t)record->time.tv_sec,
 367                 record->time.tv_nsec / 1000,
 368                 record->compressed ? 'C' : 'D');
 369         WARN_ON_ONCE(!hdr);
 370         len = hdr ? strlen(hdr) : 0;
 371         persistent_ram_write(prz, hdr, len);
 372         kfree(hdr);
 373
 374         return len;
 375 }
 376
 377 static int notrace ramoops_pstore_write(struct pstore_record *record)
 378 {
 379         struct ramoops_context *cxt = record->psi->data;
 380         struct persistent_ram_zone *prz;
 381         size_t size, hlen;
 382
 383         if (record->type == PSTORE_TYPE_CONSOLE) {
 384                 if (!cxt->cprz)
 385                         return -ENOMEM;
 386                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 387                 return 0;
 388         } else if (record->type == PSTORE_TYPE_FTRACE) {
 389                 int zonenum;
 390
 391                 if (!cxt->fprzs)
 392                         return -ENOMEM;
 393                 /*
 394                  * Choose zone by if we're using per-cpu buffers.
 395                  */
 396                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 397                         zonenum = smp_processor_id();
 398                 else
 399                         zonenum = 0;
 400
 401                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 402                                      record->size);
 403                 return 0;
 404         } else if (record->type == PSTORE_TYPE_PMSG) {
 405                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 406                 return -EINVAL;
 407         }
 408
 409         if (record->type != PSTORE_TYPE_DMESG)
 410                 return -EINVAL;
 411
 412         /*
 413          * Out of the various dmesg dump types, ramoops is currently designed
 414          * to only store crash logs, rather than storing general kernel logs.
 415          */
 416         if (record->reason != KMSG_DUMP_OOPS &&
 417             record->reason != KMSG_DUMP_PANIC)
 418                 return -EINVAL;
 419
 420         /* Skip Oopes when configured to do so. */
 421         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 422                 return -EINVAL;
 423
 424         /*
 425          * Explicitly only take the first part of any new crash.
 426          * If our buffer is larger than kmsg_bytes, this can never happen,
 427          * and if our buffer is smaller than kmsg_bytes, we don't want the
 428          * report split across multiple records.
 429          */
 430         if (record->part != 1)
 431                 return -ENOSPC;
 432
 433         if (!cxt->dprzs)
 434                 return -ENOSPC;
 435
 436         prz = cxt->dprzs[cxt->dump_write_cnt];
 437
 438         /* Build header and append record contents. */
 439         hlen = ramoops_write_kmsg_hdr(prz, record);
 440         size = record->size;
 441         if (size + hlen > prz->buffer_size)
 442                 size = prz->buffer_size - hlen;
 443         persistent_ram_write(prz, record->buf, size);
 444
 445         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 446
 447         return 0;
 448 }
 449
 450 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 451                                              const char __user *buf)
 452 {
 453         if (record->type == PSTORE_TYPE_PMSG) {
 454                 struct ramoops_context *cxt = record->psi->data;
 455
 456                 if (!cxt->mprz)
 457                         return -ENOMEM;
 458                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 459         }
 460
 461         return -EINVAL;
 462 }
 463
 464 static int ramoops_pstore_erase(struct pstore_record *record)
 465 {
 466         struct ramoops_context *cxt = record->psi->data;
 467         struct persistent_ram_zone *prz;
 468
 469         switch (record->type) {
 470         case PSTORE_TYPE_DMESG:
 471                 if (record->id >= cxt->max_dump_cnt)
 472                         return -EINVAL;
 473                 prz = cxt->dprzs[record->id];
 474                 break;
 475         case PSTORE_TYPE_CONSOLE:
 476                 prz = cxt->cprz;
 477                 break;
 478         case PSTORE_TYPE_FTRACE:
 479                 if (record->id >= cxt->max_ftrace_cnt)
 480                         return -EINVAL;
 481                 prz = cxt->fprzs[record->id];
 482                 break;
 483         case PSTORE_TYPE_PMSG:
 484                 prz = cxt->mprz;
 485                 break;
 486         default:
 487                 return -EINVAL;
 488         }
 489
 490         persistent_ram_free_old(prz);
 491         persistent_ram_zap(prz);
 492
 493         return 0;
 494 }
 495
 496 static struct ramoops_context oops_cxt = {
 497         .pstore = {
 498                 .owner  = THIS_MODULE,
 499                 .name   = "ramoops",
 500                 .open   = ramoops_pstore_open,
 501                 .read   = ramoops_pstore_read,
 502                 .write  = ramoops_pstore_write,
 503                 .write_user     = ramoops_pstore_write_user,
 504                 .erase  = ramoops_pstore_erase,
 505         },
 506 };
 507
 508 static void ramoops_free_przs(struct ramoops_context *cxt)
 509 {
 510         int i;
 511
 512         /* Free dump PRZs */
 513         if (cxt->dprzs) {
 514                 for (i = 0; i < cxt->max_dump_cnt; i++)
 515                         persistent_ram_free(cxt->dprzs[i]);
 516
 517                 kfree(cxt->dprzs);
 518                 cxt->max_dump_cnt = 0;
 519         }
 520
 521         /* Free ftrace PRZs */
 522         if (cxt->fprzs) {
 523                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 524                         persistent_ram_free(cxt->fprzs[i]);
 525                 kfree(cxt->fprzs);
 526                 cxt->max_ftrace_cnt = 0;
 527         }
 528 }
 529
 530 static int ramoops_init_przs(const char *name,
 531                              struct device *dev, struct ramoops_context *cxt,
 532                              struct persistent_ram_zone ***przs,
 533                              phys_addr_t *paddr, size_t mem_sz,
 534                              ssize_t record_size,
 535                              unsigned int *cnt, u32 sig, u32 flags)
 536 {
 537         int err = -ENOMEM;
 538         int i;
 539         size_t zone_sz;
 540         struct persistent_ram_zone **prz_ar;
 541
 542         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 543         if (mem_sz == 0 || record_size == 0) {
 544                 *cnt = 0;
 545                 return 0;
 546         }
 547
 548         /*
 549          * If we have a negative record size, calculate it based on
 550          * mem_sz / *cnt. If we have a positive record size, calculate
 551          * cnt from mem_sz / record_size.
 552          */
 553         if (record_size < 0) {
 554                 if (*cnt == 0)
 555                         return 0;
 556                 record_size = mem_sz / *cnt;
 557                 if (record_size == 0) {
 558                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 559                                 name, mem_sz, *cnt);
 560                         goto fail;
 561                 }
 562         } else {
 563                 *cnt = mem_sz / record_size;
 564                 if (*cnt == 0) {
 565                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 566                                 name, mem_sz, record_size);
 567                         goto fail;
 568                 }
 569         }
 570
 571         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 572                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 573                         name,
 574                         mem_sz, (unsigned long long)*paddr,
 575                         cxt->size, (unsigned long long)cxt->phys_addr);
 576                 goto fail;
 577         }
 578
 579         zone_sz = mem_sz / *cnt;
 580         if (!zone_sz) {
 581                 dev_err(dev, "%s zone size == 0\n", name);
 582                 goto fail;
 583         }
 584
 585         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 586         if (!prz_ar)
 587                 goto fail;
 588
 589         for (i = 0; i < *cnt; i++) {
 590                 char *label;
 591
 592                 if (*cnt == 1)
 593                         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 594                 else
 595                         label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
 596                                           name, i, *cnt - 1);
 597                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 598                                                &cxt->ecc_info,
 599                                                cxt->memtype, flags, label);
 600                 if (IS_ERR(prz_ar[i])) {
 601                         err = PTR_ERR(prz_ar[i]);
 602                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 603                                 name, record_size,
 604                                 (unsigned long long)*paddr, err);
 605
 606                         while (i > 0) {
 607                                 i--;
 608                                 persistent_ram_free(prz_ar[i]);
 609                         }
 610                         kfree(prz_ar);
 611                         goto fail;
 612                 }
 613                 *paddr += zone_sz;
 614         }
 615
 616         *przs = prz_ar;
 617         return 0;
 618
 619 fail:
 620         *cnt = 0;
 621         return err;
 622 }
 623
 624 static int ramoops_init_prz(const char *name,
 625                             struct device *dev, struct ramoops_context *cxt,
 626                             struct persistent_ram_zone **prz,
 627                             phys_addr_t *paddr, size_t sz, u32 sig)
 628 {
 629         char *label;
 630
 631         if (!sz)
 632                 return 0;
 633
 634         if (*paddr + sz - cxt->phys_addr > cxt->size) {
 635                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 636                         name, sz, (unsigned long long)*paddr,
 637                         cxt->size, (unsigned long long)cxt->phys_addr);
 638                 return -ENOMEM;
 639         }
 640
 641         label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
 642         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 643                                   cxt->memtype, 0, label);
 644         if (IS_ERR(*prz)) {
 645                 int err = PTR_ERR(*prz);
 646
 647                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 648                         name, sz, (unsigned long long)*paddr, err);
 649                 return err;
 650         }
 651
 652         persistent_ram_zap(*prz);
 653
 654         *paddr += sz;
 655
 656         return 0;
 657 }
 658
 659 static int ramoops_parse_dt_size(struct platform_device *pdev,
 660                                  const char *propname, u32 *value)
 661 {
 662         u32 val32 = 0;
 663         int ret;
 664
 665         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 666         if (ret < 0 && ret != -EINVAL) {
 667                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 668                         propname, ret);
 669                 return ret;
 670         }
 671
 672         if (val32 > INT_MAX) {
 673                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 674                 return -EOVERFLOW;
 675         }
 676
 677         *value = val32;
 678         return 0;
 679 }
 680
 681 static int ramoops_parse_dt(struct platform_device *pdev,
 682                             struct ramoops_platform_data *pdata)
 683 {
 684         struct device_node *of_node = pdev->dev.of_node;
 685         struct resource *res;
 686         u32 value;
 687         int ret;
 688
 689         dev_dbg(&pdev->dev, "using Device Tree\n");
 690
 691         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 692         if (!res) {
 693                 dev_err(&pdev->dev,
 694                         "failed to locate DT /reserved-memory resource\n");
 695                 return -EINVAL;
 696         }
 697
 698         pdata->mem_size = resource_size(res);
 699         pdata->mem_address = res->start;
 700         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 701         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 702
 703 #define parse_size(name, field) {                                       \
 704                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 705                 if (ret < 0)                                            \
 706                         return ret;                                     \
 707                 field = value;                                          \
 708         }
 709
 710         parse_size("record-size", pdata->record_size);
 711         parse_size("console-size", pdata->console_size);
 712         parse_size("ftrace-size", pdata->ftrace_size);
 713         parse_size("pmsg-size", pdata->pmsg_size);
 714         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 715         parse_size("flags", pdata->flags);
 716
 717 #undef parse_size
 718
 719         return 0;
 720 }
 721
 722 static int ramoops_probe(struct platform_device *pdev)
 723 {
 724         struct device *dev = &pdev->dev;
 725         struct ramoops_platform_data *pdata = dev->platform_data;
 726         struct ramoops_context *cxt = &oops_cxt;
 727         size_t dump_mem_sz;
 728         phys_addr_t paddr;
 729         int err = -EINVAL;
 730
 731         if (dev_of_node(dev) && !pdata) {
 732                 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 733                 if (!pdata) {
 734                         pr_err("cannot allocate platform data buffer\n");
 735                         err = -ENOMEM;
 736                         goto fail_out;
 737                 }
 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          * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
 820          * have to handle dumps, we must have at least record_size buffer. And
 821          * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
 822          * ZERO_SIZE_PTR).
 823          */
 824         if (cxt->console_size)
 825                 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
 826         cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
 827         cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
 828         if (!cxt->pstore.buf) {
 829                 pr_err("cannot allocate pstore buffer\n");
 830                 err = -ENOMEM;
 831                 goto fail_clear;
 832         }
 833         spin_lock_init(&cxt->pstore.buf_lock);
 834
 835         cxt->pstore.flags = PSTORE_FLAGS_DMESG;
 836         if (cxt->console_size)
 837                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 838         if (cxt->ftrace_size)
 839                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 840         if (cxt->pmsg_size)
 841                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 842
 843         err = pstore_register(&cxt->pstore);
 844         if (err) {
 845                 pr_err("registering with pstore failed\n");
 846                 goto fail_buf;
 847         }
 848
 849         /*
 850          * Update the module parameter variables as well so they are visible
 851          * through /sys/module/ramoops/parameters/
 852          */
 853         mem_size = pdata->mem_size;
 854         mem_address = pdata->mem_address;
 855         record_size = pdata->record_size;
 856         dump_oops = pdata->dump_oops;
 857         ramoops_console_size = pdata->console_size;
 858         ramoops_pmsg_size = pdata->pmsg_size;
 859         ramoops_ftrace_size = pdata->ftrace_size;
 860
 861         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 862                 cxt->size, (unsigned long long)cxt->phys_addr,
 863                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 864
 865         return 0;
 866
 867 fail_buf:
 868         kfree(cxt->pstore.buf);
 869 fail_clear:
 870         cxt->pstore.bufsize = 0;
 871         persistent_ram_free(cxt->mprz);
 872 fail_init_mprz:
 873 fail_init_fprz:
 874         persistent_ram_free(cxt->cprz);
 875 fail_init_cprz:
 876         ramoops_free_przs(cxt);
 877 fail_out:
 878         return err;
 879 }
 880
 881 static int ramoops_remove(struct platform_device *pdev)
 882 {
 883         struct ramoops_context *cxt = &oops_cxt;
 884
 885         pstore_unregister(&cxt->pstore);
 886
 887         kfree(cxt->pstore.buf);
 888         cxt->pstore.bufsize = 0;
 889
 890         persistent_ram_free(cxt->mprz);
 891         persistent_ram_free(cxt->cprz);
 892         ramoops_free_przs(cxt);
 893
 894         return 0;
 895 }
 896
 897 static const struct of_device_id dt_match[] = {
 898         { .compatible = "ramoops" },
 899         {}
 900 };
 901
 902 static struct platform_driver ramoops_driver = {
 903         .probe          = ramoops_probe,
 904         .remove         = ramoops_remove,
 905         .driver         = {
 906                 .name           = "ramoops",
 907                 .of_match_table = dt_match,
 908         },
 909 };
 910
 911 static inline void ramoops_unregister_dummy(void)
 912 {
 913         platform_device_unregister(dummy);
 914         dummy = NULL;
 915
 916         kfree(dummy_data);
 917         dummy_data = NULL;
 918 }
 919
 920 static void __init ramoops_register_dummy(void)
 921 {
 922         /*
 923          * Prepare a dummy platform data structure to carry the module
 924          * parameters. If mem_size isn't set, then there are no module
 925          * parameters, and we can skip this.
 926          */
 927         if (!mem_size)
 928                 return;
 929
 930         pr_info("using module parameters\n");
 931
 932         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 933         if (!dummy_data) {
 934                 pr_info("could not allocate pdata\n");
 935                 return;
 936         }
 937
 938         dummy_data->mem_size = mem_size;
 939         dummy_data->mem_address = mem_address;
 940         dummy_data->mem_type = mem_type;
 941         dummy_data->record_size = record_size;
 942         dummy_data->console_size = ramoops_console_size;
 943         dummy_data->ftrace_size = ramoops_ftrace_size;
 944         dummy_data->pmsg_size = ramoops_pmsg_size;
 945         dummy_data->dump_oops = dump_oops;
 946         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 947
 948         /*
 949          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 950          * (using 1 byte for ECC isn't much of use anyway).
 951          */
 952         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 953
 954         dummy = platform_device_register_data(NULL, "ramoops", -1,
 955                         dummy_data, sizeof(struct ramoops_platform_data));
 956         if (IS_ERR(dummy)) {
 957                 pr_info("could not create platform device: %ld\n",
 958                         PTR_ERR(dummy));
 959                 dummy = NULL;
 960                 ramoops_unregister_dummy();
 961         }
 962 }
 963
 964 static int __init ramoops_init(void)
 965 {
 966         int ret;
 967
 968         ramoops_register_dummy();
 969         ret = platform_driver_register(&ramoops_driver);
 970         if (ret != 0)
 971                 ramoops_unregister_dummy();
 972
 973         return ret;
 974 }
 975 postcore_initcall(ramoops_init);
 976
 977 static void __exit ramoops_exit(void)
 978 {
 979         platform_driver_unregister(&ramoops_driver);
 980         ramoops_unregister_dummy();
 981 }
 982 module_exit(ramoops_exit);
 983
 984 MODULE_LICENSE("GPL");
 985 MODULE_AUTHOR("Marco Stornelli <[email protected]>");
 986 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");