fs/pstore/ram.c

   1 /*
   2  * RAM Oops/Panic logger
   3  *
   4  * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
   5  * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19  * 02110-1301 USA
  20  *
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/kernel.h>
  26 #include <linux/err.h>
  27 #include <linux/module.h>
  28 #include <linux/version.h>
  29 #include <linux/pstore.h>
  30 #include <linux/io.h>
  31 #include <linux/ioport.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/slab.h>
  34 #include <linux/compiler.h>
  35 #include <linux/pstore_ram.h>
  36 #include <linux/of.h>
  37 #include <linux/of_address.h>
  38
  39 #define RAMOOPS_KERNMSG_HDR "===="
  40 #define MIN_MEM_SIZE 4096UL
  41
  42 static ulong record_size = MIN_MEM_SIZE;
  43 module_param(record_size, ulong, 0400);
  44 MODULE_PARM_DESC(record_size,
  45                 "size of each dump done on oops/panic");
  46
  47 static ulong ramoops_console_size = MIN_MEM_SIZE;
  48 module_param_named(console_size, ramoops_console_size, ulong, 0400);
  49 MODULE_PARM_DESC(console_size, "size of kernel console log");
  50
  51 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
  52 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
  53 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
  54
  55 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
  56 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
  57 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
  58
  59 static unsigned long long mem_address;
  60 module_param_hw(mem_address, ullong, other, 0400);
  61 MODULE_PARM_DESC(mem_address,
  62                 "start of reserved RAM used to store oops/panic logs");
  63
  64 static ulong mem_size;
  65 module_param(mem_size, ulong, 0400);
  66 MODULE_PARM_DESC(mem_size,
  67                 "size of reserved RAM used to store oops/panic logs");
  68
  69 static unsigned int mem_type;
  70 module_param(mem_type, uint, 0600);
  71 MODULE_PARM_DESC(mem_type,
  72                 "set to 1 to try to use unbuffered memory (default 0)");
  73
  74 static int dump_oops = 1;
  75 module_param(dump_oops, int, 0600);
  76 MODULE_PARM_DESC(dump_oops,
  77                 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
  78
  79 static int ramoops_ecc;
  80 module_param_named(ecc, ramoops_ecc, int, 0600);
  81 MODULE_PARM_DESC(ramoops_ecc,
  82                 "if non-zero, the option enables ECC support and specifies "
  83                 "ECC buffer size in bytes (1 is a special value, means 16 "
  84                 "bytes ECC)");
  85
  86 struct ramoops_context {
  87         struct persistent_ram_zone **dprzs;     /* Oops dump zones */
  88         struct persistent_ram_zone *cprz;       /* Console zone */
  89         struct persistent_ram_zone **fprzs;     /* Ftrace zones */
  90         struct persistent_ram_zone *mprz;       /* PMSG zone */
  91         phys_addr_t phys_addr;
  92         unsigned long size;
  93         unsigned int memtype;
  94         size_t record_size;
  95         size_t console_size;
  96         size_t ftrace_size;
  97         size_t pmsg_size;
  98         int dump_oops;
  99         u32 flags;
 100         struct persistent_ram_ecc_info ecc_info;
 101         unsigned int max_dump_cnt;
 102         unsigned int dump_write_cnt;
 103         /* _read_cnt need clear on ramoops_pstore_open */
 104         unsigned int dump_read_cnt;
 105         unsigned int console_read_cnt;
 106         unsigned int max_ftrace_cnt;
 107         unsigned int ftrace_read_cnt;
 108         unsigned int pmsg_read_cnt;
 109         struct pstore_info pstore;
 110 };
 111
 112 static struct platform_device *dummy;
 113 static struct ramoops_platform_data *dummy_data;
 114
 115 static int ramoops_pstore_open(struct pstore_info *psi)
 116 {
 117         struct ramoops_context *cxt = psi->data;
 118
 119         cxt->dump_read_cnt = 0;
 120         cxt->console_read_cnt = 0;
 121         cxt->ftrace_read_cnt = 0;
 122         cxt->pmsg_read_cnt = 0;
 123         return 0;
 124 }
 125
 126 static struct persistent_ram_zone *
 127 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
 128                      u64 *id,
 129                      enum pstore_type_id *typep, enum pstore_type_id type,
 130                      bool update)
 131 {
 132         struct persistent_ram_zone *prz;
 133         int i = (*c)++;
 134
 135         /* Give up if we never existed or have hit the end. */
 136         if (!przs || i >= max)
 137                 return NULL;
 138
 139         prz = przs[i];
 140         if (!prz)
 141                 return NULL;
 142
 143         /* Update old/shadowed buffer. */
 144         if (update)
 145                 persistent_ram_save_old(prz);
 146
 147         if (!persistent_ram_old_size(prz))
 148                 return NULL;
 149
 150         *typep = type;
 151         *id = i;
 152
 153         return prz;
 154 }
 155
 156 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
 157                                   bool *compressed)
 158 {
 159         char data_type;
 160         int header_length = 0;
 161
 162         if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
 163                         &time->tv_nsec, &data_type, &header_length) == 3) {
 164                 if (data_type == 'C')
 165                         *compressed = true;
 166                 else
 167                         *compressed = false;
 168         } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
 169                         &time->tv_sec, &time->tv_nsec, &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                                            cxt->max_dump_cnt, &record->id,
 258                                            &record->type,
 259                                            PSTORE_TYPE_DMESG, 1);
 260                 if (!prz_ok(prz))
 261                         continue;
 262                 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
 263                                                       &record->time,
 264                                                       &record->compressed);
 265                 /* Clear and skip this DMESG record if it has no valid header */
 266                 if (!header_length) {
 267                         persistent_ram_free_old(prz);
 268                         persistent_ram_zap(prz);
 269                         prz = NULL;
 270                 }
 271         }
 272
 273         if (!prz_ok(prz))
 274                 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
 275                                            1, &record->id, &record->type,
 276                                            PSTORE_TYPE_CONSOLE, 0);
 277
 278         if (!prz_ok(prz))
 279                 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
 280                                            1, &record->id, &record->type,
 281                                            PSTORE_TYPE_PMSG, 0);
 282
 283         /* ftrace is last since it may want to dynamically allocate memory. */
 284         if (!prz_ok(prz)) {
 285                 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
 286                         prz = ramoops_get_next_prz(cxt->fprzs,
 287                                         &cxt->ftrace_read_cnt, 1, &record->id,
 288                                         &record->type, PSTORE_TYPE_FTRACE, 0);
 289                 } else {
 290                         /*
 291                          * Build a new dummy record which combines all the
 292                          * per-cpu records including metadata and ecc info.
 293                          */
 294                         struct persistent_ram_zone *tmp_prz, *prz_next;
 295
 296                         tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
 297                                           GFP_KERNEL);
 298                         if (!tmp_prz)
 299                                 return -ENOMEM;
 300                         prz = tmp_prz;
 301                         free_prz = true;
 302
 303                         while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
 304                                 prz_next = ramoops_get_next_prz(cxt->fprzs,
 305                                                 &cxt->ftrace_read_cnt,
 306                                                 cxt->max_ftrace_cnt,
 307                                                 &record->id,
 308                                                 &record->type,
 309                                                 PSTORE_TYPE_FTRACE, 0);
 310
 311                                 if (!prz_ok(prz_next))
 312                                         continue;
 313
 314                                 tmp_prz->ecc_info = prz_next->ecc_info;
 315                                 tmp_prz->corrected_bytes +=
 316                                                 prz_next->corrected_bytes;
 317                                 tmp_prz->bad_blocks += prz_next->bad_blocks;
 318                                 size = ftrace_log_combine(tmp_prz, prz_next);
 319                                 if (size)
 320                                         goto out;
 321                         }
 322                         record->id = 0;
 323                 }
 324         }
 325
 326         if (!prz_ok(prz)) {
 327                 size = 0;
 328                 goto out;
 329         }
 330
 331         size = persistent_ram_old_size(prz) - header_length;
 332
 333         /* ECC correction notice */
 334         record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
 335
 336         record->buf = kmalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
 337         if (record->buf == NULL) {
 338                 size = -ENOMEM;
 339                 goto out;
 340         }
 341
 342         memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
 343                size);
 344
 345         persistent_ram_ecc_string(prz, record->buf + size,
 346                                   record->ecc_notice_size + 1);
 347
 348 out:
 349         if (free_prz) {
 350                 kfree(prz->old_log);
 351                 kfree(prz);
 352         }
 353
 354         return size;
 355 }
 356
 357 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
 358                                      struct pstore_record *record)
 359 {
 360         char *hdr;
 361         size_t len;
 362
 363         hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
 364                 record->time.tv_sec,
 365                 record->time.tv_nsec / 1000,
 366                 record->compressed ? 'C' : 'D');
 367         WARN_ON_ONCE(!hdr);
 368         len = hdr ? strlen(hdr) : 0;
 369         persistent_ram_write(prz, hdr, len);
 370         kfree(hdr);
 371
 372         return len;
 373 }
 374
 375 static int notrace ramoops_pstore_write(struct pstore_record *record)
 376 {
 377         struct ramoops_context *cxt = record->psi->data;
 378         struct persistent_ram_zone *prz;
 379         size_t size, hlen;
 380
 381         if (record->type == PSTORE_TYPE_CONSOLE) {
 382                 if (!cxt->cprz)
 383                         return -ENOMEM;
 384                 persistent_ram_write(cxt->cprz, record->buf, record->size);
 385                 return 0;
 386         } else if (record->type == PSTORE_TYPE_FTRACE) {
 387                 int zonenum;
 388
 389                 if (!cxt->fprzs)
 390                         return -ENOMEM;
 391                 /*
 392                  * Choose zone by if we're using per-cpu buffers.
 393                  */
 394                 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 395                         zonenum = smp_processor_id();
 396                 else
 397                         zonenum = 0;
 398
 399                 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
 400                                      record->size);
 401                 return 0;
 402         } else if (record->type == PSTORE_TYPE_PMSG) {
 403                 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
 404                 return -EINVAL;
 405         }
 406
 407         if (record->type != PSTORE_TYPE_DMESG)
 408                 return -EINVAL;
 409
 410         /*
 411          * Out of the various dmesg dump types, ramoops is currently designed
 412          * to only store crash logs, rather than storing general kernel logs.
 413          */
 414         if (record->reason != KMSG_DUMP_OOPS &&
 415             record->reason != KMSG_DUMP_PANIC)
 416                 return -EINVAL;
 417
 418         /* Skip Oopes when configured to do so. */
 419         if (record->reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
 420                 return -EINVAL;
 421
 422         /*
 423          * Explicitly only take the first part of any new crash.
 424          * If our buffer is larger than kmsg_bytes, this can never happen,
 425          * and if our buffer is smaller than kmsg_bytes, we don't want the
 426          * report split across multiple records.
 427          */
 428         if (record->part != 1)
 429                 return -ENOSPC;
 430
 431         if (!cxt->dprzs)
 432                 return -ENOSPC;
 433
 434         prz = cxt->dprzs[cxt->dump_write_cnt];
 435
 436         /*
 437          * Since this is a new crash dump, we need to reset the buffer in
 438          * case it still has an old dump present. Without this, the new dump
 439          * will get appended, which would seriously confuse anything trying
 440          * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
 441          * expects to find a dump header in the beginning of buffer data, so
 442          * we must to reset the buffer values, in order to ensure that the
 443          * header will be written to the beginning of the buffer.
 444          */
 445         persistent_ram_zap(prz);
 446
 447         /* Build header and append record contents. */
 448         hlen = ramoops_write_kmsg_hdr(prz, record);
 449         size = record->size;
 450         if (size + hlen > prz->buffer_size)
 451                 size = prz->buffer_size - hlen;
 452         persistent_ram_write(prz, record->buf, size);
 453
 454         cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
 455
 456         return 0;
 457 }
 458
 459 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
 460                                              const char __user *buf)
 461 {
 462         if (record->type == PSTORE_TYPE_PMSG) {
 463                 struct ramoops_context *cxt = record->psi->data;
 464
 465                 if (!cxt->mprz)
 466                         return -ENOMEM;
 467                 return persistent_ram_write_user(cxt->mprz, buf, record->size);
 468         }
 469
 470         return -EINVAL;
 471 }
 472
 473 static int ramoops_pstore_erase(struct pstore_record *record)
 474 {
 475         struct ramoops_context *cxt = record->psi->data;
 476         struct persistent_ram_zone *prz;
 477
 478         switch (record->type) {
 479         case PSTORE_TYPE_DMESG:
 480                 if (record->id >= cxt->max_dump_cnt)
 481                         return -EINVAL;
 482                 prz = cxt->dprzs[record->id];
 483                 break;
 484         case PSTORE_TYPE_CONSOLE:
 485                 prz = cxt->cprz;
 486                 break;
 487         case PSTORE_TYPE_FTRACE:
 488                 if (record->id >= cxt->max_ftrace_cnt)
 489                         return -EINVAL;
 490                 prz = cxt->fprzs[record->id];
 491                 break;
 492         case PSTORE_TYPE_PMSG:
 493                 prz = cxt->mprz;
 494                 break;
 495         default:
 496                 return -EINVAL;
 497         }
 498
 499         persistent_ram_free_old(prz);
 500         persistent_ram_zap(prz);
 501
 502         return 0;
 503 }
 504
 505 static struct ramoops_context oops_cxt = {
 506         .pstore = {
 507                 .owner  = THIS_MODULE,
 508                 .name   = "ramoops",
 509                 .open   = ramoops_pstore_open,
 510                 .read   = ramoops_pstore_read,
 511                 .write  = ramoops_pstore_write,
 512                 .write_user     = ramoops_pstore_write_user,
 513                 .erase  = ramoops_pstore_erase,
 514         },
 515 };
 516
 517 static void ramoops_free_przs(struct ramoops_context *cxt)
 518 {
 519         int i;
 520
 521         /* Free dump PRZs */
 522         if (cxt->dprzs) {
 523                 for (i = 0; i < cxt->max_dump_cnt; i++)
 524                         persistent_ram_free(cxt->dprzs[i]);
 525
 526                 kfree(cxt->dprzs);
 527                 cxt->max_dump_cnt = 0;
 528         }
 529
 530         /* Free ftrace PRZs */
 531         if (cxt->fprzs) {
 532                 for (i = 0; i < cxt->max_ftrace_cnt; i++)
 533                         persistent_ram_free(cxt->fprzs[i]);
 534                 kfree(cxt->fprzs);
 535                 cxt->max_ftrace_cnt = 0;
 536         }
 537 }
 538
 539 static int ramoops_init_przs(const char *name,
 540                              struct device *dev, struct ramoops_context *cxt,
 541                              struct persistent_ram_zone ***przs,
 542                              phys_addr_t *paddr, size_t mem_sz,
 543                              ssize_t record_size,
 544                              unsigned int *cnt, u32 sig, u32 flags)
 545 {
 546         int err = -ENOMEM;
 547         int i;
 548         size_t zone_sz;
 549         struct persistent_ram_zone **prz_ar;
 550
 551         /* Allocate nothing for 0 mem_sz or 0 record_size. */
 552         if (mem_sz == 0 || record_size == 0) {
 553                 *cnt = 0;
 554                 return 0;
 555         }
 556
 557         /*
 558          * If we have a negative record size, calculate it based on
 559          * mem_sz / *cnt. If we have a positive record size, calculate
 560          * cnt from mem_sz / record_size.
 561          */
 562         if (record_size < 0) {
 563                 if (*cnt == 0)
 564                         return 0;
 565                 record_size = mem_sz / *cnt;
 566                 if (record_size == 0) {
 567                         dev_err(dev, "%s record size == 0 (%zu / %u)\n",
 568                                 name, mem_sz, *cnt);
 569                         goto fail;
 570                 }
 571         } else {
 572                 *cnt = mem_sz / record_size;
 573                 if (*cnt == 0) {
 574                         dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
 575                                 name, mem_sz, record_size);
 576                         goto fail;
 577                 }
 578         }
 579
 580         if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
 581                 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
 582                         name,
 583                         mem_sz, (unsigned long long)*paddr,
 584                         cxt->size, (unsigned long long)cxt->phys_addr);
 585                 goto fail;
 586         }
 587
 588         zone_sz = mem_sz / *cnt;
 589         if (!zone_sz) {
 590                 dev_err(dev, "%s zone size == 0\n", name);
 591                 goto fail;
 592         }
 593
 594         prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
 595         if (!prz_ar)
 596                 goto fail;
 597
 598         for (i = 0; i < *cnt; i++) {
 599                 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
 600                                                   &cxt->ecc_info,
 601                                                   cxt->memtype, flags);
 602                 if (IS_ERR(prz_ar[i])) {
 603                         err = PTR_ERR(prz_ar[i]);
 604                         dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 605                                 name, record_size,
 606                                 (unsigned long long)*paddr, err);
 607
 608                         while (i > 0) {
 609                                 i--;
 610                                 persistent_ram_free(prz_ar[i]);
 611                         }
 612                         kfree(prz_ar);
 613                         goto fail;
 614                 }
 615                 *paddr += zone_sz;
 616         }
 617
 618         *przs = prz_ar;
 619         return 0;
 620
 621 fail:
 622         *cnt = 0;
 623         return err;
 624 }
 625
 626 static int ramoops_init_prz(const char *name,
 627                             struct device *dev, struct ramoops_context *cxt,
 628                             struct persistent_ram_zone **prz,
 629                             phys_addr_t *paddr, size_t sz, u32 sig)
 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         *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
 642                                   cxt->memtype, 0);
 643         if (IS_ERR(*prz)) {
 644                 int err = PTR_ERR(*prz);
 645
 646                 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 647                         name, sz, (unsigned long long)*paddr, err);
 648                 return err;
 649         }
 650
 651         persistent_ram_zap(*prz);
 652
 653         *paddr += sz;
 654
 655         return 0;
 656 }
 657
 658 static int ramoops_parse_dt_size(struct platform_device *pdev,
 659                                  const char *propname, u32 *value)
 660 {
 661         u32 val32 = 0;
 662         int ret;
 663
 664         ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
 665         if (ret < 0 && ret != -EINVAL) {
 666                 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
 667                         propname, ret);
 668                 return ret;
 669         }
 670
 671         if (val32 > INT_MAX) {
 672                 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
 673                 return -EOVERFLOW;
 674         }
 675
 676         *value = val32;
 677         return 0;
 678 }
 679
 680 static int ramoops_parse_dt(struct platform_device *pdev,
 681                             struct ramoops_platform_data *pdata)
 682 {
 683         struct device_node *of_node = pdev->dev.of_node;
 684         struct resource *res;
 685         u32 value;
 686         int ret;
 687
 688         dev_dbg(&pdev->dev, "using Device Tree\n");
 689
 690         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 691         if (!res) {
 692                 dev_err(&pdev->dev,
 693                         "failed to locate DT /reserved-memory resource\n");
 694                 return -EINVAL;
 695         }
 696
 697         pdata->mem_size = resource_size(res);
 698         pdata->mem_address = res->start;
 699         pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
 700         pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
 701
 702 #define parse_size(name, field) {                                       \
 703                 ret = ramoops_parse_dt_size(pdev, name, &value);        \
 704                 if (ret < 0)                                            \
 705                         return ret;                                     \
 706                 field = value;                                          \
 707         }
 708
 709         parse_size("record-size", pdata->record_size);
 710         parse_size("console-size", pdata->console_size);
 711         parse_size("ftrace-size", pdata->ftrace_size);
 712         parse_size("pmsg-size", pdata->pmsg_size);
 713         parse_size("ecc-size", pdata->ecc_info.ecc_size);
 714         parse_size("flags", pdata->flags);
 715
 716 #undef parse_size
 717
 718         return 0;
 719 }
 720
 721 static int ramoops_probe(struct platform_device *pdev)
 722 {
 723         struct device *dev = &pdev->dev;
 724         struct ramoops_platform_data *pdata = dev->platform_data;
 725         struct ramoops_platform_data pdata_local;
 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 = &pdata_local;
 733                 memset(pdata, 0, sizeof(*pdata));
 734
 735                 err = ramoops_parse_dt(pdev, pdata);
 736                 if (err < 0)
 737                         goto fail_out;
 738         }
 739
 740         /*
 741          * Only a single ramoops area allowed at a time, so fail extra
 742          * probes.
 743          */
 744         if (cxt->max_dump_cnt) {
 745                 pr_err("already initialized\n");
 746                 goto fail_out;
 747         }
 748
 749         /* Make sure we didn't get bogus platform data pointer. */
 750         if (!pdata) {
 751                 pr_err("NULL platform data\n");
 752                 err = -EINVAL;
 753                 goto fail_out;
 754         }
 755
 756         if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
 757                         !pdata->ftrace_size && !pdata->pmsg_size)) {
 758                 pr_err("The memory size and the record/console size must be "
 759                         "non-zero\n");
 760                 err = -EINVAL;
 761                 goto fail_out;
 762         }
 763
 764         if (pdata->record_size && !is_power_of_2(pdata->record_size))
 765                 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
 766         if (pdata->console_size && !is_power_of_2(pdata->console_size))
 767                 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
 768         if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
 769                 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
 770         if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
 771                 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
 772
 773         cxt->size = pdata->mem_size;
 774         cxt->phys_addr = pdata->mem_address;
 775         cxt->memtype = pdata->mem_type;
 776         cxt->record_size = pdata->record_size;
 777         cxt->console_size = pdata->console_size;
 778         cxt->ftrace_size = pdata->ftrace_size;
 779         cxt->pmsg_size = pdata->pmsg_size;
 780         cxt->dump_oops = pdata->dump_oops;
 781         cxt->flags = pdata->flags;
 782         cxt->ecc_info = pdata->ecc_info;
 783
 784         paddr = cxt->phys_addr;
 785
 786         dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
 787                         - cxt->pmsg_size;
 788         err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
 789                                 dump_mem_sz, cxt->record_size,
 790                                 &cxt->max_dump_cnt, 0, 0);
 791         if (err)
 792                 goto fail_out;
 793
 794         err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
 795                                cxt->console_size, 0);
 796         if (err)
 797                 goto fail_init_cprz;
 798
 799         cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 800                                 ? nr_cpu_ids
 801                                 : 1;
 802         err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
 803                                 cxt->ftrace_size, -1,
 804                                 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
 805                                 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
 806                                         ? PRZ_FLAG_NO_LOCK : 0);
 807         if (err)
 808                 goto fail_init_fprz;
 809
 810         err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
 811                                 cxt->pmsg_size, 0);
 812         if (err)
 813                 goto fail_init_mprz;
 814
 815         cxt->pstore.data = cxt;
 816         /*
 817          * Prepare frontend flags based on which areas are initialized.
 818          * For ramoops_init_przs() cases, the "max count" variable tells
 819          * if there are regions present. For ramoops_init_prz() cases,
 820          * the single region size is how to check.
 821          */
 822         cxt->pstore.flags = 0;
 823         if (cxt->max_dump_cnt)
 824                 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
 825         if (cxt->console_size)
 826                 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
 827         if (cxt->max_ftrace_cnt)
 828                 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
 829         if (cxt->pmsg_size)
 830                 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
 831
 832         /*
 833          * Since bufsize is only used for dmesg crash dumps, it
 834          * must match the size of the dprz record (after PRZ header
 835          * and ECC bytes have been accounted for).
 836          */
 837         if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
 838                 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
 839                 cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL);
 840                 if (!cxt->pstore.buf) {
 841                         pr_err("cannot allocate pstore crash dump buffer\n");
 842                         err = -ENOMEM;
 843                         goto fail_clear;
 844                 }
 845         }
 846
 847         err = pstore_register(&cxt->pstore);
 848         if (err) {
 849                 pr_err("registering with pstore failed\n");
 850                 goto fail_buf;
 851         }
 852
 853         /*
 854          * Update the module parameter variables as well so they are visible
 855          * through /sys/module/ramoops/parameters/
 856          */
 857         mem_size = pdata->mem_size;
 858         mem_address = pdata->mem_address;
 859         record_size = pdata->record_size;
 860         dump_oops = pdata->dump_oops;
 861         ramoops_console_size = pdata->console_size;
 862         ramoops_pmsg_size = pdata->pmsg_size;
 863         ramoops_ftrace_size = pdata->ftrace_size;
 864
 865         pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
 866                 cxt->size, (unsigned long long)cxt->phys_addr,
 867                 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
 868
 869         return 0;
 870
 871 fail_buf:
 872         kfree(cxt->pstore.buf);
 873 fail_clear:
 874         cxt->pstore.bufsize = 0;
 875         persistent_ram_free(cxt->mprz);
 876 fail_init_mprz:
 877 fail_init_fprz:
 878         persistent_ram_free(cxt->cprz);
 879 fail_init_cprz:
 880         ramoops_free_przs(cxt);
 881 fail_out:
 882         return err;
 883 }
 884
 885 static int ramoops_remove(struct platform_device *pdev)
 886 {
 887         struct ramoops_context *cxt = &oops_cxt;
 888
 889         pstore_unregister(&cxt->pstore);
 890
 891         kfree(cxt->pstore.buf);
 892         cxt->pstore.bufsize = 0;
 893
 894         persistent_ram_free(cxt->mprz);
 895         persistent_ram_free(cxt->cprz);
 896         ramoops_free_przs(cxt);
 897
 898         return 0;
 899 }
 900
 901 static const struct of_device_id dt_match[] = {
 902         { .compatible = "ramoops" },
 903         {}
 904 };
 905
 906 static struct platform_driver ramoops_driver = {
 907         .probe          = ramoops_probe,
 908         .remove         = ramoops_remove,
 909         .driver         = {
 910                 .name           = "ramoops",
 911                 .of_match_table = dt_match,
 912         },
 913 };
 914
 915 static void ramoops_register_dummy(void)
 916 {
 917         if (!mem_size)
 918                 return;
 919
 920         pr_info("using module parameters\n");
 921
 922         dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
 923         if (!dummy_data) {
 924                 pr_info("could not allocate pdata\n");
 925                 return;
 926         }
 927
 928         dummy_data->mem_size = mem_size;
 929         dummy_data->mem_address = mem_address;
 930         dummy_data->mem_type = mem_type;
 931         dummy_data->record_size = record_size;
 932         dummy_data->console_size = ramoops_console_size;
 933         dummy_data->ftrace_size = ramoops_ftrace_size;
 934         dummy_data->pmsg_size = ramoops_pmsg_size;
 935         dummy_data->dump_oops = dump_oops;
 936         dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
 937
 938         /*
 939          * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
 940          * (using 1 byte for ECC isn't much of use anyway).
 941          */
 942         dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
 943
 944         dummy = platform_device_register_data(NULL, "ramoops", -1,
 945                         dummy_data, sizeof(struct ramoops_platform_data));
 946         if (IS_ERR(dummy)) {
 947                 pr_info("could not create platform device: %ld\n",
 948                         PTR_ERR(dummy));
 949         }
 950 }
 951
 952 static int __init ramoops_init(void)
 953 {
 954         ramoops_register_dummy();
 955         return platform_driver_register(&ramoops_driver);
 956 }
 957 postcore_initcall(ramoops_init);
 958
 959 static void __exit ramoops_exit(void)
 960 {
 961         platform_driver_unregister(&ramoops_driver);
 962         platform_device_unregister(dummy);
 963         kfree(dummy_data);
 964 }
 965 module_exit(ramoops_exit);
 966
 967 MODULE_LICENSE("GPL");
 968 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
 969 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");