arch/powerpc/kernel/nvram_64.c

   1 /*
   2  *  c 2001 PPC 64 Team, IBM Corp
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  * /dev/nvram driver for PPC64
  10  *
  11  * This perhaps should live in drivers/char
  12  *
  13  * TODO: Split the /dev/nvram part (that one can use
  14  *       drivers/char/generic_nvram.c) from the arch & partition
  15  *       parsing code.
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/errno.h>
  20 #include <linux/fs.h>
  21 #include <linux/miscdevice.h>
  22 #include <linux/fcntl.h>
  23 #include <linux/nvram.h>
  24 #include <linux/init.h>
  25 #include <linux/slab.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/kmsg_dump.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/pstore.h>
  30 #include <linux/zlib.h>
  31 #include <linux/uaccess.h>
  32 #include <asm/nvram.h>
  33 #include <asm/rtas.h>
  34 #include <asm/prom.h>
  35 #include <asm/machdep.h>
  36
  37 #undef DEBUG_NVRAM
  38
  39 #define NVRAM_HEADER_LEN        sizeof(struct nvram_header)
  40 #define NVRAM_BLOCK_LEN         NVRAM_HEADER_LEN
  41
  42 /* If change this size, then change the size of NVNAME_LEN */
  43 struct nvram_header {
  44         unsigned char signature;
  45         unsigned char checksum;
  46         unsigned short length;
  47         /* Terminating null required only for names < 12 chars. */
  48         char name[12];
  49 };
  50
  51 struct nvram_partition {
  52         struct list_head partition;
  53         struct nvram_header header;
  54         unsigned int index;
  55 };
  56
  57 static LIST_HEAD(nvram_partitions);
  58
  59 #ifdef CONFIG_PPC_PSERIES
  60 struct nvram_os_partition rtas_log_partition = {
  61         .name = "ibm,rtas-log",
  62         .req_size = 2079,
  63         .min_size = 1055,
  64         .index = -1,
  65         .os_partition = true
  66 };
  67 #endif
  68
  69 struct nvram_os_partition oops_log_partition = {
  70         .name = "lnx,oops-log",
  71         .req_size = 4000,
  72         .min_size = 2000,
  73         .index = -1,
  74         .os_partition = true
  75 };
  76
  77 static const char *nvram_os_partitions[] = {
  78 #ifdef CONFIG_PPC_PSERIES
  79         "ibm,rtas-log",
  80 #endif
  81         "lnx,oops-log",
  82         NULL
  83 };
  84
  85 static void oops_to_nvram(struct kmsg_dumper *dumper,
  86                           enum kmsg_dump_reason reason);
  87
  88 static struct kmsg_dumper nvram_kmsg_dumper = {
  89         .dump = oops_to_nvram
  90 };
  91
  92 /*
  93  * For capturing and compressing an oops or panic report...
  94
  95  * big_oops_buf[] holds the uncompressed text we're capturing.
  96  *
  97  * oops_buf[] holds the compressed text, preceded by a oops header.
  98  * oops header has u16 holding the version of oops header (to differentiate
  99  * between old and new format header) followed by u16 holding the length of
 100  * the compressed* text (*Or uncompressed, if compression fails.) and u64
 101  * holding the timestamp. oops_buf[] gets written to NVRAM.
 102  *
 103  * oops_log_info points to the header. oops_data points to the compressed text.
 104  *
 105  * +- oops_buf
 106  * |                                   +- oops_data
 107  * v                                   v
 108  * +-----------+-----------+-----------+------------------------+
 109  * | version   | length    | timestamp | text                   |
 110  * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
 111  * +-----------+-----------+-----------+------------------------+
 112  * ^
 113  * +- oops_log_info
 114  *
 115  * We preallocate these buffers during init to avoid kmalloc during oops/panic.
 116  */
 117 static size_t big_oops_buf_sz;
 118 static char *big_oops_buf, *oops_buf;
 119 static char *oops_data;
 120 static size_t oops_data_sz;
 121
 122 /* Compression parameters */
 123 #define COMPR_LEVEL 6
 124 #define WINDOW_BITS 12
 125 #define MEM_LEVEL 4
 126 static struct z_stream_s stream;
 127
 128 #ifdef CONFIG_PSTORE
 129 #ifdef CONFIG_PPC_POWERNV
 130 static struct nvram_os_partition skiboot_partition = {
 131         .name = "ibm,skiboot",
 132         .index = -1,
 133         .os_partition = false
 134 };
 135 #endif
 136
 137 #ifdef CONFIG_PPC_PSERIES
 138 static struct nvram_os_partition of_config_partition = {
 139         .name = "of-config",
 140         .index = -1,
 141         .os_partition = false
 142 };
 143 #endif
 144
 145 static struct nvram_os_partition common_partition = {
 146         .name = "common",
 147         .index = -1,
 148         .os_partition = false
 149 };
 150
 151 static enum pstore_type_id nvram_type_ids[] = {
 152         PSTORE_TYPE_DMESG,
 153         PSTORE_TYPE_PPC_COMMON,
 154         -1,
 155         -1,
 156         -1
 157 };
 158 static int read_type;
 159 #endif
 160
 161 /* nvram_write_os_partition
 162  *
 163  * We need to buffer the error logs into nvram to ensure that we have
 164  * the failure information to decode.  If we have a severe error there
 165  * is no way to guarantee that the OS or the machine is in a state to
 166  * get back to user land and write the error to disk.  For example if
 167  * the SCSI device driver causes a Machine Check by writing to a bad
 168  * IO address, there is no way of guaranteeing that the device driver
 169  * is in any state that is would also be able to write the error data
 170  * captured to disk, thus we buffer it in NVRAM for analysis on the
 171  * next boot.
 172  *
 173  * In NVRAM the partition containing the error log buffer will looks like:
 174  * Header (in bytes):
 175  * +-----------+----------+--------+------------+------------------+
 176  * | signature | checksum | length | name       | data             |
 177  * |0          |1         |2      3|4         15|16        length-1|
 178  * +-----------+----------+--------+------------+------------------+
 179  *
 180  * The 'data' section would look like (in bytes):
 181  * +--------------+------------+-----------------------------------+
 182  * | event_logged | sequence # | error log                         |
 183  * |0            3|4          7|8                  error_log_size-1|
 184  * +--------------+------------+-----------------------------------+
 185  *
 186  * event_logged: 0 if event has not been logged to syslog, 1 if it has
 187  * sequence #: The unique sequence # for each event. (until it wraps)
 188  * error log: The error log from event_scan
 189  */
 190 int nvram_write_os_partition(struct nvram_os_partition *part,
 191                              char *buff, int length,
 192                              unsigned int err_type,
 193                              unsigned int error_log_cnt)
 194 {
 195         int rc;
 196         loff_t tmp_index;
 197         struct err_log_info info;
 198
 199         if (part->index == -1)
 200                 return -ESPIPE;
 201
 202         if (length > part->size)
 203                 length = part->size;
 204
 205         info.error_type = cpu_to_be32(err_type);
 206         info.seq_num = cpu_to_be32(error_log_cnt);
 207
 208         tmp_index = part->index;
 209
 210         rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
 211                                 &tmp_index);
 212         if (rc <= 0) {
 213                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 214                 return rc;
 215         }
 216
 217         rc = ppc_md.nvram_write(buff, length, &tmp_index);
 218         if (rc <= 0) {
 219                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 220                 return rc;
 221         }
 222
 223         return 0;
 224 }
 225
 226 /* nvram_read_partition
 227  *
 228  * Reads nvram partition for at most 'length'
 229  */
 230 int nvram_read_partition(struct nvram_os_partition *part, char *buff,
 231                          int length, unsigned int *err_type,
 232                          unsigned int *error_log_cnt)
 233 {
 234         int rc;
 235         loff_t tmp_index;
 236         struct err_log_info info;
 237
 238         if (part->index == -1)
 239                 return -1;
 240
 241         if (length > part->size)
 242                 length = part->size;
 243
 244         tmp_index = part->index;
 245
 246         if (part->os_partition) {
 247                 rc = ppc_md.nvram_read((char *)&info,
 248                                         sizeof(struct err_log_info),
 249                                         &tmp_index);
 250                 if (rc <= 0) {
 251                         pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 252                         return rc;
 253                 }
 254         }
 255
 256         rc = ppc_md.nvram_read(buff, length, &tmp_index);
 257         if (rc <= 0) {
 258                 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 259                 return rc;
 260         }
 261
 262         if (part->os_partition) {
 263                 *error_log_cnt = be32_to_cpu(info.seq_num);
 264                 *err_type = be32_to_cpu(info.error_type);
 265         }
 266
 267         return 0;
 268 }
 269
 270 /* nvram_init_os_partition
 271  *
 272  * This sets up a partition with an "OS" signature.
 273  *
 274  * The general strategy is the following:
 275  * 1.) If a partition with the indicated name already exists...
 276  *      - If it's large enough, use it.
 277  *      - Otherwise, recycle it and keep going.
 278  * 2.) Search for a free partition that is large enough.
 279  * 3.) If there's not a free partition large enough, recycle any obsolete
 280  * OS partitions and try again.
 281  * 4.) Will first try getting a chunk that will satisfy the requested size.
 282  * 5.) If a chunk of the requested size cannot be allocated, then try finding
 283  * a chunk that will satisfy the minum needed.
 284  *
 285  * Returns 0 on success, else -1.
 286  */
 287 int __init nvram_init_os_partition(struct nvram_os_partition *part)
 288 {
 289         loff_t p;
 290         int size;
 291
 292         /* Look for ours */
 293         p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
 294
 295         /* Found one but too small, remove it */
 296         if (p && size < part->min_size) {
 297                 pr_info("nvram: Found too small %s partition,"
 298                                         " removing it...\n", part->name);
 299                 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
 300                 p = 0;
 301         }
 302
 303         /* Create one if we didn't find */
 304         if (!p) {
 305                 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 306                                         part->req_size, part->min_size);
 307                 if (p == -ENOSPC) {
 308                         pr_info("nvram: No room to create %s partition, "
 309                                 "deleting any obsolete OS partitions...\n",
 310                                 part->name);
 311                         nvram_remove_partition(NULL, NVRAM_SIG_OS,
 312                                         nvram_os_partitions);
 313                         p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 314                                         part->req_size, part->min_size);
 315                 }
 316         }
 317
 318         if (p <= 0) {
 319                 pr_err("nvram: Failed to find or create %s"
 320                        " partition, err %d\n", part->name, (int)p);
 321                 return -1;
 322         }
 323
 324         part->index = p;
 325         part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
 326
 327         return 0;
 328 }
 329
 330 /* Derived from logfs_compress() */
 331 static int nvram_compress(const void *in, void *out, size_t inlen,
 332                                                         size_t outlen)
 333 {
 334         int err, ret;
 335
 336         ret = -EIO;
 337         err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
 338                                                 MEM_LEVEL, Z_DEFAULT_STRATEGY);
 339         if (err != Z_OK)
 340                 goto error;
 341
 342         stream.next_in = in;
 343         stream.avail_in = inlen;
 344         stream.total_in = 0;
 345         stream.next_out = out;
 346         stream.avail_out = outlen;
 347         stream.total_out = 0;
 348
 349         err = zlib_deflate(&stream, Z_FINISH);
 350         if (err != Z_STREAM_END)
 351                 goto error;
 352
 353         err = zlib_deflateEnd(&stream);
 354         if (err != Z_OK)
 355                 goto error;
 356
 357         if (stream.total_out >= stream.total_in)
 358                 goto error;
 359
 360         ret = stream.total_out;
 361 error:
 362         return ret;
 363 }
 364
 365 /* Compress the text from big_oops_buf into oops_buf. */
 366 static int zip_oops(size_t text_len)
 367 {
 368         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 369         int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
 370                                                                 oops_data_sz);
 371         if (zipped_len < 0) {
 372                 pr_err("nvram: compression failed; returned %d\n", zipped_len);
 373                 pr_err("nvram: logging uncompressed oops/panic report\n");
 374                 return -1;
 375         }
 376         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 377         oops_hdr->report_length = cpu_to_be16(zipped_len);
 378         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 379         return 0;
 380 }
 381
 382 #ifdef CONFIG_PSTORE
 383 static int nvram_pstore_open(struct pstore_info *psi)
 384 {
 385         /* Reset the iterator to start reading partitions again */
 386         read_type = -1;
 387         return 0;
 388 }
 389
 390 /**
 391  * nvram_pstore_write - pstore write callback for nvram
 392  * @record:             pstore record to write, with @id to be set
 393  *
 394  * Called by pstore_dump() when an oops or panic report is logged in the
 395  * printk buffer.
 396  * Returns 0 on successful write.
 397  */
 398 static int nvram_pstore_write(struct pstore_record *record)
 399 {
 400         int rc;
 401         unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
 402         struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
 403
 404         /* part 1 has the recent messages from printk buffer */
 405         if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG))
 406                 return -1;
 407
 408         if (clobbering_unread_rtas_event())
 409                 return -1;
 410
 411         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 412         oops_hdr->report_length = cpu_to_be16(record->size);
 413         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 414
 415         if (record->compressed)
 416                 err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 417
 418         rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
 419                 (int) (sizeof(*oops_hdr) + record->size), err_type,
 420                 record->count);
 421
 422         if (rc != 0)
 423                 return rc;
 424
 425         record->id = record->part;
 426         return 0;
 427 }
 428
 429 /*
 430  * Reads the oops/panic report, rtas, of-config and common partition.
 431  * Returns the length of the data we read from each partition.
 432  * Returns 0 if we've been called before.
 433  */
 434 static ssize_t nvram_pstore_read(struct pstore_record *record)
 435 {
 436         struct oops_log_info *oops_hdr;
 437         unsigned int err_type, id_no, size = 0;
 438         struct nvram_os_partition *part = NULL;
 439         char *buff = NULL;
 440         int sig = 0;
 441         loff_t p;
 442
 443         read_type++;
 444
 445         switch (nvram_type_ids[read_type]) {
 446         case PSTORE_TYPE_DMESG:
 447                 part = &oops_log_partition;
 448                 record->type = PSTORE_TYPE_DMESG;
 449                 break;
 450         case PSTORE_TYPE_PPC_COMMON:
 451                 sig = NVRAM_SIG_SYS;
 452                 part = &common_partition;
 453                 record->type = PSTORE_TYPE_PPC_COMMON;
 454                 record->id = PSTORE_TYPE_PPC_COMMON;
 455                 record->time.tv_sec = 0;
 456                 record->time.tv_nsec = 0;
 457                 break;
 458 #ifdef CONFIG_PPC_PSERIES
 459         case PSTORE_TYPE_PPC_RTAS:
 460                 part = &rtas_log_partition;
 461                 record->type = PSTORE_TYPE_PPC_RTAS;
 462                 record->time.tv_sec = last_rtas_event;
 463                 record->time.tv_nsec = 0;
 464                 break;
 465         case PSTORE_TYPE_PPC_OF:
 466                 sig = NVRAM_SIG_OF;
 467                 part = &of_config_partition;
 468                 record->type = PSTORE_TYPE_PPC_OF;
 469                 record->id = PSTORE_TYPE_PPC_OF;
 470                 record->time.tv_sec = 0;
 471                 record->time.tv_nsec = 0;
 472                 break;
 473 #endif
 474 #ifdef CONFIG_PPC_POWERNV
 475         case PSTORE_TYPE_PPC_OPAL:
 476                 sig = NVRAM_SIG_FW;
 477                 part = &skiboot_partition;
 478                 record->type = PSTORE_TYPE_PPC_OPAL;
 479                 record->id = PSTORE_TYPE_PPC_OPAL;
 480                 record->time.tv_sec = 0;
 481                 record->time.tv_nsec = 0;
 482                 break;
 483 #endif
 484         default:
 485                 return 0;
 486         }
 487
 488         if (!part->os_partition) {
 489                 p = nvram_find_partition(part->name, sig, &size);
 490                 if (p <= 0) {
 491                         pr_err("nvram: Failed to find partition %s, "
 492                                 "err %d\n", part->name, (int)p);
 493                         return 0;
 494                 }
 495                 part->index = p;
 496                 part->size = size;
 497         }
 498
 499         buff = kmalloc(part->size, GFP_KERNEL);
 500
 501         if (!buff)
 502                 return -ENOMEM;
 503
 504         if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
 505                 kfree(buff);
 506                 return 0;
 507         }
 508
 509         record->count = 0;
 510
 511         if (part->os_partition)
 512                 record->id = id_no;
 513
 514         if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
 515                 size_t length, hdr_size;
 516
 517                 oops_hdr = (struct oops_log_info *)buff;
 518                 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
 519                         /* Old format oops header had 2-byte record size */
 520                         hdr_size = sizeof(u16);
 521                         length = be16_to_cpu(oops_hdr->version);
 522                         record->time.tv_sec = 0;
 523                         record->time.tv_nsec = 0;
 524                 } else {
 525                         hdr_size = sizeof(*oops_hdr);
 526                         length = be16_to_cpu(oops_hdr->report_length);
 527                         record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp);
 528                         record->time.tv_nsec = 0;
 529                 }
 530                 record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
 531                 kfree(buff);
 532                 if (record->buf == NULL)
 533                         return -ENOMEM;
 534
 535                 record->ecc_notice_size = 0;
 536                 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
 537                         record->compressed = true;
 538                 else
 539                         record->compressed = false;
 540                 return length;
 541         }
 542
 543         record->buf = buff;
 544         return part->size;
 545 }
 546
 547 static struct pstore_info nvram_pstore_info = {
 548         .owner = THIS_MODULE,
 549         .name = "nvram",
 550         .flags = PSTORE_FLAGS_DMESG,
 551         .open = nvram_pstore_open,
 552         .read = nvram_pstore_read,
 553         .write = nvram_pstore_write,
 554 };
 555
 556 static int nvram_pstore_init(void)
 557 {
 558         int rc = 0;
 559
 560         if (machine_is(pseries)) {
 561                 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
 562                 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
 563         } else
 564                 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
 565
 566         nvram_pstore_info.buf = oops_data;
 567         nvram_pstore_info.bufsize = oops_data_sz;
 568
 569         rc = pstore_register(&nvram_pstore_info);
 570         if (rc && (rc != -EPERM))
 571                 /* Print error only when pstore.backend == nvram */
 572                 pr_err("nvram: pstore_register() failed, returned %d. "
 573                                 "Defaults to kmsg_dump\n", rc);
 574
 575         return rc;
 576 }
 577 #else
 578 static int nvram_pstore_init(void)
 579 {
 580         return -1;
 581 }
 582 #endif
 583
 584 void __init nvram_init_oops_partition(int rtas_partition_exists)
 585 {
 586         int rc;
 587
 588         rc = nvram_init_os_partition(&oops_log_partition);
 589         if (rc != 0) {
 590 #ifdef CONFIG_PPC_PSERIES
 591                 if (!rtas_partition_exists) {
 592                         pr_err("nvram: Failed to initialize oops partition!");
 593                         return;
 594                 }
 595                 pr_notice("nvram: Using %s partition to log both"
 596                         " RTAS errors and oops/panic reports\n",
 597                         rtas_log_partition.name);
 598                 memcpy(&oops_log_partition, &rtas_log_partition,
 599                                                 sizeof(rtas_log_partition));
 600 #else
 601                 pr_err("nvram: Failed to initialize oops partition!");
 602                 return;
 603 #endif
 604         }
 605         oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
 606         if (!oops_buf) {
 607                 pr_err("nvram: No memory for %s partition\n",
 608                                                 oops_log_partition.name);
 609                 return;
 610         }
 611         oops_data = oops_buf + sizeof(struct oops_log_info);
 612         oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
 613
 614         rc = nvram_pstore_init();
 615
 616         if (!rc)
 617                 return;
 618
 619         /*
 620          * Figure compression (preceded by elimination of each line's <n>
 621          * severity prefix) will reduce the oops/panic report to at most
 622          * 45% of its original size.
 623          */
 624         big_oops_buf_sz = (oops_data_sz * 100) / 45;
 625         big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 626         if (big_oops_buf) {
 627                 stream.workspace =  kmalloc(zlib_deflate_workspacesize(
 628                                         WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
 629                 if (!stream.workspace) {
 630                         pr_err("nvram: No memory for compression workspace; "
 631                                 "skipping compression of %s partition data\n",
 632                                 oops_log_partition.name);
 633                         kfree(big_oops_buf);
 634                         big_oops_buf = NULL;
 635                 }
 636         } else {
 637                 pr_err("No memory for uncompressed %s data; "
 638                         "skipping compression\n", oops_log_partition.name);
 639                 stream.workspace = NULL;
 640         }
 641
 642         rc = kmsg_dump_register(&nvram_kmsg_dumper);
 643         if (rc != 0) {
 644                 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
 645                 kfree(oops_buf);
 646                 kfree(big_oops_buf);
 647                 kfree(stream.workspace);
 648         }
 649 }
 650
 651 /*
 652  * This is our kmsg_dump callback, called after an oops or panic report
 653  * has been written to the printk buffer.  We want to capture as much
 654  * of the printk buffer as possible.  First, capture as much as we can
 655  * that we think will compress sufficiently to fit in the lnx,oops-log
 656  * partition.  If that's too much, go back and capture uncompressed text.
 657  */
 658 static void oops_to_nvram(struct kmsg_dumper *dumper,
 659                           enum kmsg_dump_reason reason)
 660 {
 661         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 662         static unsigned int oops_count = 0;
 663         static bool panicking = false;
 664         static DEFINE_SPINLOCK(lock);
 665         unsigned long flags;
 666         size_t text_len;
 667         unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 668         int rc = -1;
 669
 670         switch (reason) {
 671         case KMSG_DUMP_RESTART:
 672         case KMSG_DUMP_HALT:
 673         case KMSG_DUMP_POWEROFF:
 674                 /* These are almost always orderly shutdowns. */
 675                 return;
 676         case KMSG_DUMP_OOPS:
 677                 break;
 678         case KMSG_DUMP_PANIC:
 679                 panicking = true;
 680                 break;
 681         case KMSG_DUMP_EMERG:
 682                 if (panicking)
 683                         /* Panic report already captured. */
 684                         return;
 685                 break;
 686         default:
 687                 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
 688                        __func__, (int) reason);
 689                 return;
 690         }
 691
 692         if (clobbering_unread_rtas_event())
 693                 return;
 694
 695         if (!spin_trylock_irqsave(&lock, flags))
 696                 return;
 697
 698         if (big_oops_buf) {
 699                 kmsg_dump_get_buffer(dumper, false,
 700                                      big_oops_buf, big_oops_buf_sz, &text_len);
 701                 rc = zip_oops(text_len);
 702         }
 703         if (rc != 0) {
 704                 kmsg_dump_rewind(dumper);
 705                 kmsg_dump_get_buffer(dumper, false,
 706                                      oops_data, oops_data_sz, &text_len);
 707                 err_type = ERR_TYPE_KERNEL_PANIC;
 708                 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 709                 oops_hdr->report_length = cpu_to_be16(text_len);
 710                 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 711         }
 712
 713         (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
 714                 (int) (sizeof(*oops_hdr) + text_len), err_type,
 715                 ++oops_count);
 716
 717         spin_unlock_irqrestore(&lock, flags);
 718 }
 719
 720 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
 721 {
 722         if (ppc_md.nvram_size == NULL)
 723                 return -ENODEV;
 724         return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
 725                                         ppc_md.nvram_size());
 726 }
 727
 728
 729 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
 730                           size_t count, loff_t *ppos)
 731 {
 732         ssize_t ret;
 733         char *tmp = NULL;
 734         ssize_t size;
 735
 736         if (!ppc_md.nvram_size) {
 737                 ret = -ENODEV;
 738                 goto out;
 739         }
 740
 741         size = ppc_md.nvram_size();
 742         if (size < 0) {
 743                 ret = size;
 744                 goto out;
 745         }
 746
 747         if (*ppos >= size) {
 748                 ret = 0;
 749                 goto out;
 750         }
 751
 752         count = min_t(size_t, count, size - *ppos);
 753         count = min(count, PAGE_SIZE);
 754
 755         tmp = kmalloc(count, GFP_KERNEL);
 756         if (!tmp) {
 757                 ret = -ENOMEM;
 758                 goto out;
 759         }
 760
 761         ret = ppc_md.nvram_read(tmp, count, ppos);
 762         if (ret <= 0)
 763                 goto out;
 764
 765         if (copy_to_user(buf, tmp, ret))
 766                 ret = -EFAULT;
 767
 768 out:
 769         kfree(tmp);
 770         return ret;
 771
 772 }
 773
 774 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
 775                           size_t count, loff_t *ppos)
 776 {
 777         ssize_t ret;
 778         char *tmp = NULL;
 779         ssize_t size;
 780
 781         ret = -ENODEV;
 782         if (!ppc_md.nvram_size)
 783                 goto out;
 784
 785         ret = 0;
 786         size = ppc_md.nvram_size();
 787         if (*ppos >= size || size < 0)
 788                 goto out;
 789
 790         count = min_t(size_t, count, size - *ppos);
 791         count = min(count, PAGE_SIZE);
 792
 793         tmp = memdup_user(buf, count);
 794         if (IS_ERR(tmp)) {
 795                 ret = PTR_ERR(tmp);
 796                 goto out;
 797         }
 798
 799         ret = ppc_md.nvram_write(tmp, count, ppos);
 800
 801         kfree(tmp);
 802 out:
 803         return ret;
 804 }
 805
 806 static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
 807                             unsigned long arg)
 808 {
 809         switch(cmd) {
 810 #ifdef CONFIG_PPC_PMAC
 811         case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
 812                 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
 813         case IOC_NVRAM_GET_OFFSET: {
 814                 int part, offset;
 815
 816                 if (!machine_is(powermac))
 817                         return -EINVAL;
 818                 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
 819                         return -EFAULT;
 820                 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
 821                         return -EINVAL;
 822                 offset = pmac_get_partition(part);
 823                 if (offset < 0)
 824                         return offset;
 825                 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
 826                         return -EFAULT;
 827                 return 0;
 828         }
 829 #endif /* CONFIG_PPC_PMAC */
 830         default:
 831                 return -EINVAL;
 832         }
 833 }
 834
 835 static const struct file_operations nvram_fops = {
 836         .owner          = THIS_MODULE,
 837         .llseek         = dev_nvram_llseek,
 838         .read           = dev_nvram_read,
 839         .write          = dev_nvram_write,
 840         .unlocked_ioctl = dev_nvram_ioctl,
 841 };
 842
 843 static struct miscdevice nvram_dev = {
 844         NVRAM_MINOR,
 845         "nvram",
 846         &nvram_fops
 847 };
 848
 849
 850 #ifdef DEBUG_NVRAM
 851 static void __init nvram_print_partitions(char * label)
 852 {
 853         struct nvram_partition * tmp_part;
 854
 855         printk(KERN_WARNING "--------%s---------\n", label);
 856         printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
 857         list_for_each_entry(tmp_part, &nvram_partitions, partition) {
 858                 printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%12.12s\n",
 859                        tmp_part->index, tmp_part->header.signature,
 860                        tmp_part->header.checksum, tmp_part->header.length,
 861                        tmp_part->header.name);
 862         }
 863 }
 864 #endif
 865
 866
 867 static int __init nvram_write_header(struct nvram_partition * part)
 868 {
 869         loff_t tmp_index;
 870         int rc;
 871         struct nvram_header phead;
 872
 873         memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
 874         phead.length = cpu_to_be16(phead.length);
 875
 876         tmp_index = part->index;
 877         rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
 878
 879         return rc;
 880 }
 881
 882
 883 static unsigned char __init nvram_checksum(struct nvram_header *p)
 884 {
 885         unsigned int c_sum, c_sum2;
 886         unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
 887         c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
 888
 889         /* The sum may have spilled into the 3rd byte.  Fold it back. */
 890         c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
 891         /* The sum cannot exceed 2 bytes.  Fold it into a checksum */
 892         c_sum2 = (c_sum >> 8) + (c_sum << 8);
 893         c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
 894         return c_sum;
 895 }
 896
 897 /*
 898  * Per the criteria passed via nvram_remove_partition(), should this
 899  * partition be removed?  1=remove, 0=keep
 900  */
 901 static int nvram_can_remove_partition(struct nvram_partition *part,
 902                 const char *name, int sig, const char *exceptions[])
 903 {
 904         if (part->header.signature != sig)
 905                 return 0;
 906         if (name) {
 907                 if (strncmp(name, part->header.name, 12))
 908                         return 0;
 909         } else if (exceptions) {
 910                 const char **except;
 911                 for (except = exceptions; *except; except++) {
 912                         if (!strncmp(*except, part->header.name, 12))
 913                                 return 0;
 914                 }
 915         }
 916         return 1;
 917 }
 918
 919 /**
 920  * nvram_remove_partition - Remove one or more partitions in nvram
 921  * @name: name of the partition to remove, or NULL for a
 922  *        signature only match
 923  * @sig: signature of the partition(s) to remove
 924  * @exceptions: When removing all partitions with a matching signature,
 925  *        leave these alone.
 926  */
 927
 928 int __init nvram_remove_partition(const char *name, int sig,
 929                                                 const char *exceptions[])
 930 {
 931         struct nvram_partition *part, *prev, *tmp;
 932         int rc;
 933
 934         list_for_each_entry(part, &nvram_partitions, partition) {
 935                 if (!nvram_can_remove_partition(part, name, sig, exceptions))
 936                         continue;
 937
 938                 /* Make partition a free partition */
 939                 part->header.signature = NVRAM_SIG_FREE;
 940                 memset(part->header.name, 'w', 12);
 941                 part->header.checksum = nvram_checksum(&part->header);
 942                 rc = nvram_write_header(part);
 943                 if (rc <= 0) {
 944                         printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 945                         return rc;
 946                 }
 947         }
 948
 949         /* Merge contiguous ones */
 950         prev = NULL;
 951         list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
 952                 if (part->header.signature != NVRAM_SIG_FREE) {
 953                         prev = NULL;
 954                         continue;
 955                 }
 956                 if (prev) {
 957                         prev->header.length += part->header.length;
 958                         prev->header.checksum = nvram_checksum(&prev->header);
 959                         rc = nvram_write_header(prev);
 960                         if (rc <= 0) {
 961                                 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 962                                 return rc;
 963                         }
 964                         list_del(&part->partition);
 965                         kfree(part);
 966                 } else
 967                         prev = part;
 968         }
 969
 970         return 0;
 971 }
 972
 973 /**
 974  * nvram_create_partition - Create a partition in nvram
 975  * @name: name of the partition to create
 976  * @sig: signature of the partition to create
 977  * @req_size: size of data to allocate in bytes
 978  * @min_size: minimum acceptable size (0 means req_size)
 979  *
 980  * Returns a negative error code or a positive nvram index
 981  * of the beginning of the data area of the newly created
 982  * partition. If you provided a min_size smaller than req_size
 983  * you need to query for the actual size yourself after the
 984  * call using nvram_partition_get_size().
 985  */
 986 loff_t __init nvram_create_partition(const char *name, int sig,
 987                                      int req_size, int min_size)
 988 {
 989         struct nvram_partition *part;
 990         struct nvram_partition *new_part;
 991         struct nvram_partition *free_part = NULL;
 992         static char nv_init_vals[16];
 993         loff_t tmp_index;
 994         long size = 0;
 995         int rc;
 996
 997         /* Convert sizes from bytes to blocks */
 998         req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
 999         min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
1000
1001         /* If no minimum size specified, make it the same as the
1002          * requested size
1003          */
1004         if (min_size == 0)
1005                 min_size = req_size;
1006         if (min_size > req_size)
1007                 return -EINVAL;
1008
1009         /* Now add one block to each for the header */
1010         req_size += 1;
1011         min_size += 1;
1012
1013         /* Find a free partition that will give us the maximum needed size
1014            If can't find one that will give us the minimum size needed */
1015         list_for_each_entry(part, &nvram_partitions, partition) {
1016                 if (part->header.signature != NVRAM_SIG_FREE)
1017                         continue;
1018
1019                 if (part->header.length >= req_size) {
1020                         size = req_size;
1021                         free_part = part;
1022                         break;
1023                 }
1024                 if (part->header.length > size &&
1025                     part->header.length >= min_size) {
1026                         size = part->header.length;
1027                         free_part = part;
1028                 }
1029         }
1030         if (!size)
1031                 return -ENOSPC;
1032
1033         /* Create our OS partition */
1034         new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1035         if (!new_part) {
1036                 pr_err("%s: kmalloc failed\n", __func__);
1037                 return -ENOMEM;
1038         }
1039
1040         new_part->index = free_part->index;
1041         new_part->header.signature = sig;
1042         new_part->header.length = size;
1043         strncpy(new_part->header.name, name, 12);
1044         new_part->header.checksum = nvram_checksum(&new_part->header);
1045
1046         rc = nvram_write_header(new_part);
1047         if (rc <= 0) {
1048                 pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
1049                 kfree(new_part);
1050                 return rc;
1051         }
1052         list_add_tail(&new_part->partition, &free_part->partition);
1053
1054         /* Adjust or remove the partition we stole the space from */
1055         if (free_part->header.length > size) {
1056                 free_part->index += size * NVRAM_BLOCK_LEN;
1057                 free_part->header.length -= size;
1058                 free_part->header.checksum = nvram_checksum(&free_part->header);
1059                 rc = nvram_write_header(free_part);
1060                 if (rc <= 0) {
1061                         pr_err("%s: nvram_write_header failed (%d)\n",
1062                                __func__, rc);
1063                         return rc;
1064                 }
1065         } else {
1066                 list_del(&free_part->partition);
1067                 kfree(free_part);
1068         }
1069
1070         /* Clear the new partition */
1071         for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
1072              tmp_index <  ((size - 1) * NVRAM_BLOCK_LEN);
1073              tmp_index += NVRAM_BLOCK_LEN) {
1074                 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
1075                 if (rc <= 0) {
1076                         pr_err("%s: nvram_write failed (%d)\n",
1077                                __func__, rc);
1078                         return rc;
1079                 }
1080         }
1081
1082         return new_part->index + NVRAM_HEADER_LEN;
1083 }
1084
1085 /**
1086  * nvram_get_partition_size - Get the data size of an nvram partition
1087  * @data_index: This is the offset of the start of the data of
1088  *              the partition. The same value that is returned by
1089  *              nvram_create_partition().
1090  */
1091 int nvram_get_partition_size(loff_t data_index)
1092 {
1093         struct nvram_partition *part;
1094
1095         list_for_each_entry(part, &nvram_partitions, partition) {
1096                 if (part->index + NVRAM_HEADER_LEN == data_index)
1097                         return (part->header.length - 1) * NVRAM_BLOCK_LEN;
1098         }
1099         return -1;
1100 }
1101
1102
1103 /**
1104  * nvram_find_partition - Find an nvram partition by signature and name
1105  * @name: Name of the partition or NULL for any name
1106  * @sig: Signature to test against
1107  * @out_size: if non-NULL, returns the size of the data part of the partition
1108  */
1109 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
1110 {
1111         struct nvram_partition *p;
1112
1113         list_for_each_entry(p, &nvram_partitions, partition) {
1114                 if (p->header.signature == sig &&
1115                     (!name || !strncmp(p->header.name, name, 12))) {
1116                         if (out_size)
1117                                 *out_size = (p->header.length - 1) *
1118                                         NVRAM_BLOCK_LEN;
1119                         return p->index + NVRAM_HEADER_LEN;
1120                 }
1121         }
1122         return 0;
1123 }
1124
1125 int __init nvram_scan_partitions(void)
1126 {
1127         loff_t cur_index = 0;
1128         struct nvram_header phead;
1129         struct nvram_partition * tmp_part;
1130         unsigned char c_sum;
1131         char * header;
1132         int total_size;
1133         int err;
1134
1135         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1136                 return -ENODEV;
1137         total_size = ppc_md.nvram_size();
1138
1139         header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1140         if (!header) {
1141                 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
1142                 return -ENOMEM;
1143         }
1144
1145         while (cur_index < total_size) {
1146
1147                 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
1148                 if (err != NVRAM_HEADER_LEN) {
1149                         printk(KERN_ERR "nvram_scan_partitions: Error parsing "
1150                                "nvram partitions\n");
1151                         goto out;
1152                 }
1153
1154                 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
1155
1156                 memcpy(&phead, header, NVRAM_HEADER_LEN);
1157
1158                 phead.length = be16_to_cpu(phead.length);
1159
1160                 err = 0;
1161                 c_sum = nvram_checksum(&phead);
1162                 if (c_sum != phead.checksum) {
1163                         printk(KERN_WARNING "WARNING: nvram partition checksum"
1164                                " was %02x, should be %02x!\n",
1165                                phead.checksum, c_sum);
1166                         printk(KERN_WARNING "Terminating nvram partition scan\n");
1167                         goto out;
1168                 }
1169                 if (!phead.length) {
1170                         printk(KERN_WARNING "WARNING: nvram corruption "
1171                                "detected: 0-length partition\n");
1172                         goto out;
1173                 }
1174                 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
1175                 err = -ENOMEM;
1176                 if (!tmp_part) {
1177                         printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
1178                         goto out;
1179                 }
1180
1181                 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
1182                 tmp_part->index = cur_index;
1183                 list_add_tail(&tmp_part->partition, &nvram_partitions);
1184
1185                 cur_index += phead.length * NVRAM_BLOCK_LEN;
1186         }
1187         err = 0;
1188
1189 #ifdef DEBUG_NVRAM
1190         nvram_print_partitions("NVRAM Partitions");
1191 #endif
1192
1193  out:
1194         kfree(header);
1195         return err;
1196 }
1197
1198 static int __init nvram_init(void)
1199 {
1200         int rc;
1201
1202         BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
1203
1204         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1205                 return  -ENODEV;
1206
1207         rc = misc_register(&nvram_dev);
1208         if (rc != 0) {
1209                 printk(KERN_ERR "nvram_init: failed to register device\n");
1210                 return rc;
1211         }
1212
1213         return rc;
1214 }
1215 device_initcall(nvram_init);