kernel/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/module.h>
  19
  20 #include <linux/types.h>
  21 #include <linux/errno.h>
  22 #include <linux/fs.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/fcntl.h>
  25 #include <linux/nvram.h>
  26 #include <linux/init.h>
  27 #include <linux/slab.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/kmsg_dump.h>
  30 #include <linux/pstore.h>
  31 #include <linux/zlib.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/nvram.h>
  34 #include <asm/rtas.h>
  35 #include <asm/prom.h>
  36 #include <asm/machdep.h>
  37
  38 #undef DEBUG_NVRAM
  39
  40 #define NVRAM_HEADER_LEN        sizeof(struct nvram_header)
  41 #define NVRAM_BLOCK_LEN         NVRAM_HEADER_LEN
  42
  43 /* If change this size, then change the size of NVNAME_LEN */
  44 struct nvram_header {
  45         unsigned char signature;
  46         unsigned char checksum;
  47         unsigned short length;
  48         /* Terminating null required only for names < 12 chars. */
  49         char name[12];
  50 };
  51
  52 struct nvram_partition {
  53         struct list_head partition;
  54         struct nvram_header header;
  55         unsigned int index;
  56 };
  57
  58 static LIST_HEAD(nvram_partitions);
  59
  60 #ifdef CONFIG_PPC_PSERIES
  61 struct nvram_os_partition rtas_log_partition = {
  62         .name = "ibm,rtas-log",
  63         .req_size = 2079,
  64         .min_size = 1055,
  65         .index = -1,
  66         .os_partition = true
  67 };
  68 #endif
  69
  70 struct nvram_os_partition oops_log_partition = {
  71         .name = "lnx,oops-log",
  72         .req_size = 4000,
  73         .min_size = 2000,
  74         .index = -1,
  75         .os_partition = true
  76 };
  77
  78 static const char *nvram_os_partitions[] = {
  79 #ifdef CONFIG_PPC_PSERIES
  80         "ibm,rtas-log",
  81 #endif
  82         "lnx,oops-log",
  83         NULL
  84 };
  85
  86 static void oops_to_nvram(struct kmsg_dumper *dumper,
  87                           enum kmsg_dump_reason reason);
  88
  89 static struct kmsg_dumper nvram_kmsg_dumper = {
  90         .dump = oops_to_nvram
  91 };
  92
  93 /*
  94  * For capturing and compressing an oops or panic report...
  95
  96  * big_oops_buf[] holds the uncompressed text we're capturing.
  97  *
  98  * oops_buf[] holds the compressed text, preceded by a oops header.
  99  * oops header has u16 holding the version of oops header (to differentiate
 100  * between old and new format header) followed by u16 holding the length of
 101  * the compressed* text (*Or uncompressed, if compression fails.) and u64
 102  * holding the timestamp. oops_buf[] gets written to NVRAM.
 103  *
 104  * oops_log_info points to the header. oops_data points to the compressed text.
 105  *
 106  * +- oops_buf
 107  * |                                   +- oops_data
 108  * v                                   v
 109  * +-----------+-----------+-----------+------------------------+
 110  * | version   | length    | timestamp | text                   |
 111  * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
 112  * +-----------+-----------+-----------+------------------------+
 113  * ^
 114  * +- oops_log_info
 115  *
 116  * We preallocate these buffers during init to avoid kmalloc during oops/panic.
 117  */
 118 static size_t big_oops_buf_sz;
 119 static char *big_oops_buf, *oops_buf;
 120 static char *oops_data;
 121 static size_t oops_data_sz;
 122
 123 /* Compression parameters */
 124 #define COMPR_LEVEL 6
 125 #define WINDOW_BITS 12
 126 #define MEM_LEVEL 4
 127 static struct z_stream_s stream;
 128
 129 #ifdef CONFIG_PSTORE
 130 #ifdef CONFIG_PPC_POWERNV
 131 static struct nvram_os_partition skiboot_partition = {
 132         .name = "ibm,skiboot",
 133         .index = -1,
 134         .os_partition = false
 135 };
 136 #endif
 137
 138 #ifdef CONFIG_PPC_PSERIES
 139 static struct nvram_os_partition of_config_partition = {
 140         .name = "of-config",
 141         .index = -1,
 142         .os_partition = false
 143 };
 144 #endif
 145
 146 static struct nvram_os_partition common_partition = {
 147         .name = "common",
 148         .index = -1,
 149         .os_partition = false
 150 };
 151
 152 static enum pstore_type_id nvram_type_ids[] = {
 153         PSTORE_TYPE_DMESG,
 154         PSTORE_TYPE_PPC_COMMON,
 155         -1,
 156         -1,
 157         -1
 158 };
 159 static int read_type;
 160 #endif
 161
 162 /* nvram_write_os_partition
 163  *
 164  * We need to buffer the error logs into nvram to ensure that we have
 165  * the failure information to decode.  If we have a severe error there
 166  * is no way to guarantee that the OS or the machine is in a state to
 167  * get back to user land and write the error to disk.  For example if
 168  * the SCSI device driver causes a Machine Check by writing to a bad
 169  * IO address, there is no way of guaranteeing that the device driver
 170  * is in any state that is would also be able to write the error data
 171  * captured to disk, thus we buffer it in NVRAM for analysis on the
 172  * next boot.
 173  *
 174  * In NVRAM the partition containing the error log buffer will looks like:
 175  * Header (in bytes):
 176  * +-----------+----------+--------+------------+------------------+
 177  * | signature | checksum | length | name       | data             |
 178  * |0          |1         |2      3|4         15|16        length-1|
 179  * +-----------+----------+--------+------------+------------------+
 180  *
 181  * The 'data' section would look like (in bytes):
 182  * +--------------+------------+-----------------------------------+
 183  * | event_logged | sequence # | error log                         |
 184  * |0            3|4          7|8                  error_log_size-1|
 185  * +--------------+------------+-----------------------------------+
 186  *
 187  * event_logged: 0 if event has not been logged to syslog, 1 if it has
 188  * sequence #: The unique sequence # for each event. (until it wraps)
 189  * error log: The error log from event_scan
 190  */
 191 int nvram_write_os_partition(struct nvram_os_partition *part,
 192                              char *buff, int length,
 193                              unsigned int err_type,
 194                              unsigned int error_log_cnt)
 195 {
 196         int rc;
 197         loff_t tmp_index;
 198         struct err_log_info info;
 199
 200         if (part->index == -1)
 201                 return -ESPIPE;
 202
 203         if (length > part->size)
 204                 length = part->size;
 205
 206         info.error_type = cpu_to_be32(err_type);
 207         info.seq_num = cpu_to_be32(error_log_cnt);
 208
 209         tmp_index = part->index;
 210
 211         rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info),
 212                                 &tmp_index);
 213         if (rc <= 0) {
 214                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 215                 return rc;
 216         }
 217
 218         rc = ppc_md.nvram_write(buff, length, &tmp_index);
 219         if (rc <= 0) {
 220                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 221                 return rc;
 222         }
 223
 224         return 0;
 225 }
 226
 227 /* nvram_read_partition
 228  *
 229  * Reads nvram partition for at most 'length'
 230  */
 231 int nvram_read_partition(struct nvram_os_partition *part, char *buff,
 232                          int length, unsigned int *err_type,
 233                          unsigned int *error_log_cnt)
 234 {
 235         int rc;
 236         loff_t tmp_index;
 237         struct err_log_info info;
 238
 239         if (part->index == -1)
 240                 return -1;
 241
 242         if (length > part->size)
 243                 length = part->size;
 244
 245         tmp_index = part->index;
 246
 247         if (part->os_partition) {
 248                 rc = ppc_md.nvram_read((char *)&info,
 249                                         sizeof(struct err_log_info),
 250                                         &tmp_index);
 251                 if (rc <= 0) {
 252                         pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 253                         return rc;
 254                 }
 255         }
 256
 257         rc = ppc_md.nvram_read(buff, length, &tmp_index);
 258         if (rc <= 0) {
 259                 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 260                 return rc;
 261         }
 262
 263         if (part->os_partition) {
 264                 *error_log_cnt = be32_to_cpu(info.seq_num);
 265                 *err_type = be32_to_cpu(info.error_type);
 266         }
 267
 268         return 0;
 269 }
 270
 271 /* nvram_init_os_partition
 272  *
 273  * This sets up a partition with an "OS" signature.
 274  *
 275  * The general strategy is the following:
 276  * 1.) If a partition with the indicated name already exists...
 277  *      - If it's large enough, use it.
 278  *      - Otherwise, recycle it and keep going.
 279  * 2.) Search for a free partition that is large enough.
 280  * 3.) If there's not a free partition large enough, recycle any obsolete
 281  * OS partitions and try again.
 282  * 4.) Will first try getting a chunk that will satisfy the requested size.
 283  * 5.) If a chunk of the requested size cannot be allocated, then try finding
 284  * a chunk that will satisfy the minum needed.
 285  *
 286  * Returns 0 on success, else -1.
 287  */
 288 int __init nvram_init_os_partition(struct nvram_os_partition *part)
 289 {
 290         loff_t p;
 291         int size;
 292
 293         /* Look for ours */
 294         p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
 295
 296         /* Found one but too small, remove it */
 297         if (p && size < part->min_size) {
 298                 pr_info("nvram: Found too small %s partition,"
 299                                         " removing it...\n", part->name);
 300                 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
 301                 p = 0;
 302         }
 303
 304         /* Create one if we didn't find */
 305         if (!p) {
 306                 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 307                                         part->req_size, part->min_size);
 308                 if (p == -ENOSPC) {
 309                         pr_info("nvram: No room to create %s partition, "
 310                                 "deleting any obsolete OS partitions...\n",
 311                                 part->name);
 312                         nvram_remove_partition(NULL, NVRAM_SIG_OS,
 313                                         nvram_os_partitions);
 314                         p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 315                                         part->req_size, part->min_size);
 316                 }
 317         }
 318
 319         if (p <= 0) {
 320                 pr_err("nvram: Failed to find or create %s"
 321                        " partition, err %d\n", part->name, (int)p);
 322                 return -1;
 323         }
 324
 325         part->index = p;
 326         part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
 327
 328         return 0;
 329 }
 330
 331 /* Derived from logfs_compress() */
 332 static int nvram_compress(const void *in, void *out, size_t inlen,
 333                                                         size_t outlen)
 334 {
 335         int err, ret;
 336
 337         ret = -EIO;
 338         err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
 339                                                 MEM_LEVEL, Z_DEFAULT_STRATEGY);
 340         if (err != Z_OK)
 341                 goto error;
 342
 343         stream.next_in = in;
 344         stream.avail_in = inlen;
 345         stream.total_in = 0;
 346         stream.next_out = out;
 347         stream.avail_out = outlen;
 348         stream.total_out = 0;
 349
 350         err = zlib_deflate(&stream, Z_FINISH);
 351         if (err != Z_STREAM_END)
 352                 goto error;
 353
 354         err = zlib_deflateEnd(&stream);
 355         if (err != Z_OK)
 356                 goto error;
 357
 358         if (stream.total_out >= stream.total_in)
 359                 goto error;
 360
 361         ret = stream.total_out;
 362 error:
 363         return ret;
 364 }
 365
 366 /* Compress the text from big_oops_buf into oops_buf. */
 367 static int zip_oops(size_t text_len)
 368 {
 369         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 370         int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
 371                                                                 oops_data_sz);
 372         if (zipped_len < 0) {
 373                 pr_err("nvram: compression failed; returned %d\n", zipped_len);
 374                 pr_err("nvram: logging uncompressed oops/panic report\n");
 375                 return -1;
 376         }
 377         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 378         oops_hdr->report_length = cpu_to_be16(zipped_len);
 379         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 380         return 0;
 381 }
 382
 383 #ifdef CONFIG_PSTORE
 384 static int nvram_pstore_open(struct pstore_info *psi)
 385 {
 386         /* Reset the iterator to start reading partitions again */
 387         read_type = -1;
 388         return 0;
 389 }
 390
 391 /**
 392  * nvram_pstore_write - pstore write callback for nvram
 393  * @type:               Type of message logged
 394  * @reason:             reason behind dump (oops/panic)
 395  * @id:                 identifier to indicate the write performed
 396  * @part:               pstore writes data to registered buffer in parts,
 397  *                      part number will indicate the same.
 398  * @count:              Indicates oops count
 399  * @compressed:         Flag to indicate the log is compressed
 400  * @size:               number of bytes written to the registered buffer
 401  * @psi:                registered pstore_info structure
 402  *
 403  * Called by pstore_dump() when an oops or panic report is logged in the
 404  * printk buffer.
 405  * Returns 0 on successful write.
 406  */
 407 static int nvram_pstore_write(enum pstore_type_id type,
 408                                 enum kmsg_dump_reason reason,
 409                                 u64 *id, unsigned int part, int count,
 410                                 bool compressed, size_t size,
 411                                 struct pstore_info *psi)
 412 {
 413         int rc;
 414         unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
 415         struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
 416
 417         /* part 1 has the recent messages from printk buffer */
 418         if (part > 1 || (type != PSTORE_TYPE_DMESG))
 419                 return -1;
 420
 421         if (clobbering_unread_rtas_event())
 422                 return -1;
 423
 424         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 425         oops_hdr->report_length = cpu_to_be16(size);
 426         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 427
 428         if (compressed)
 429                 err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 430
 431         rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
 432                 (int) (sizeof(*oops_hdr) + size), err_type, count);
 433
 434         if (rc != 0)
 435                 return rc;
 436
 437         *id = part;
 438         return 0;
 439 }
 440
 441 /*
 442  * Reads the oops/panic report, rtas, of-config and common partition.
 443  * Returns the length of the data we read from each partition.
 444  * Returns 0 if we've been called before.
 445  */
 446 static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
 447                                 int *count, struct timespec *time, char **buf,
 448                                 bool *compressed, struct pstore_info *psi)
 449 {
 450         struct oops_log_info *oops_hdr;
 451         unsigned int err_type, id_no, size = 0;
 452         struct nvram_os_partition *part = NULL;
 453         char *buff = NULL;
 454         int sig = 0;
 455         loff_t p;
 456
 457         read_type++;
 458
 459         switch (nvram_type_ids[read_type]) {
 460         case PSTORE_TYPE_DMESG:
 461                 part = &oops_log_partition;
 462                 *type = PSTORE_TYPE_DMESG;
 463                 break;
 464         case PSTORE_TYPE_PPC_COMMON:
 465                 sig = NVRAM_SIG_SYS;
 466                 part = &common_partition;
 467                 *type = PSTORE_TYPE_PPC_COMMON;
 468                 *id = PSTORE_TYPE_PPC_COMMON;
 469                 time->tv_sec = 0;
 470                 time->tv_nsec = 0;
 471                 break;
 472 #ifdef CONFIG_PPC_PSERIES
 473         case PSTORE_TYPE_PPC_RTAS:
 474                 part = &rtas_log_partition;
 475                 *type = PSTORE_TYPE_PPC_RTAS;
 476                 time->tv_sec = last_rtas_event;
 477                 time->tv_nsec = 0;
 478                 break;
 479         case PSTORE_TYPE_PPC_OF:
 480                 sig = NVRAM_SIG_OF;
 481                 part = &of_config_partition;
 482                 *type = PSTORE_TYPE_PPC_OF;
 483                 *id = PSTORE_TYPE_PPC_OF;
 484                 time->tv_sec = 0;
 485                 time->tv_nsec = 0;
 486                 break;
 487 #endif
 488 #ifdef CONFIG_PPC_POWERNV
 489         case PSTORE_TYPE_PPC_OPAL:
 490                 sig = NVRAM_SIG_FW;
 491                 part = &skiboot_partition;
 492                 *type = PSTORE_TYPE_PPC_OPAL;
 493                 *id = PSTORE_TYPE_PPC_OPAL;
 494                 time->tv_sec = 0;
 495                 time->tv_nsec = 0;
 496                 break;
 497 #endif
 498         default:
 499                 return 0;
 500         }
 501
 502         if (!part->os_partition) {
 503                 p = nvram_find_partition(part->name, sig, &size);
 504                 if (p <= 0) {
 505                         pr_err("nvram: Failed to find partition %s, "
 506                                 "err %d\n", part->name, (int)p);
 507                         return 0;
 508                 }
 509                 part->index = p;
 510                 part->size = size;
 511         }
 512
 513         buff = kmalloc(part->size, GFP_KERNEL);
 514
 515         if (!buff)
 516                 return -ENOMEM;
 517
 518         if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
 519                 kfree(buff);
 520                 return 0;
 521         }
 522
 523         *count = 0;
 524
 525         if (part->os_partition)
 526                 *id = id_no;
 527
 528         if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
 529                 size_t length, hdr_size;
 530
 531                 oops_hdr = (struct oops_log_info *)buff;
 532                 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
 533                         /* Old format oops header had 2-byte record size */
 534                         hdr_size = sizeof(u16);
 535                         length = be16_to_cpu(oops_hdr->version);
 536                         time->tv_sec = 0;
 537                         time->tv_nsec = 0;
 538                 } else {
 539                         hdr_size = sizeof(*oops_hdr);
 540                         length = be16_to_cpu(oops_hdr->report_length);
 541                         time->tv_sec = be64_to_cpu(oops_hdr->timestamp);
 542                         time->tv_nsec = 0;
 543                 }
 544                 *buf = kmalloc(length, GFP_KERNEL);
 545                 if (*buf == NULL)
 546                         return -ENOMEM;
 547                 memcpy(*buf, buff + hdr_size, length);
 548                 kfree(buff);
 549
 550                 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
 551                         *compressed = true;
 552                 else
 553                         *compressed = false;
 554                 return length;
 555         }
 556
 557         *buf = buff;
 558         return part->size;
 559 }
 560
 561 static struct pstore_info nvram_pstore_info = {
 562         .owner = THIS_MODULE,
 563         .name = "nvram",
 564         .open = nvram_pstore_open,
 565         .read = nvram_pstore_read,
 566         .write = nvram_pstore_write,
 567 };
 568
 569 static int nvram_pstore_init(void)
 570 {
 571         int rc = 0;
 572
 573         if (machine_is(pseries)) {
 574                 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
 575                 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
 576         } else
 577                 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
 578
 579         nvram_pstore_info.buf = oops_data;
 580         nvram_pstore_info.bufsize = oops_data_sz;
 581
 582         spin_lock_init(&nvram_pstore_info.buf_lock);
 583
 584         rc = pstore_register(&nvram_pstore_info);
 585         if (rc != 0)
 586                 pr_err("nvram: pstore_register() failed, defaults to "
 587                                 "kmsg_dump; returned %d\n", rc);
 588
 589         return rc;
 590 }
 591 #else
 592 static int nvram_pstore_init(void)
 593 {
 594         return -1;
 595 }
 596 #endif
 597
 598 void __init nvram_init_oops_partition(int rtas_partition_exists)
 599 {
 600         int rc;
 601
 602         rc = nvram_init_os_partition(&oops_log_partition);
 603         if (rc != 0) {
 604 #ifdef CONFIG_PPC_PSERIES
 605                 if (!rtas_partition_exists) {
 606                         pr_err("nvram: Failed to initialize oops partition!");
 607                         return;
 608                 }
 609                 pr_notice("nvram: Using %s partition to log both"
 610                         " RTAS errors and oops/panic reports\n",
 611                         rtas_log_partition.name);
 612                 memcpy(&oops_log_partition, &rtas_log_partition,
 613                                                 sizeof(rtas_log_partition));
 614 #else
 615                 pr_err("nvram: Failed to initialize oops partition!");
 616                 return;
 617 #endif
 618         }
 619         oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
 620         if (!oops_buf) {
 621                 pr_err("nvram: No memory for %s partition\n",
 622                                                 oops_log_partition.name);
 623                 return;
 624         }
 625         oops_data = oops_buf + sizeof(struct oops_log_info);
 626         oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
 627
 628         rc = nvram_pstore_init();
 629
 630         if (!rc)
 631                 return;
 632
 633         /*
 634          * Figure compression (preceded by elimination of each line's <n>
 635          * severity prefix) will reduce the oops/panic report to at most
 636          * 45% of its original size.
 637          */
 638         big_oops_buf_sz = (oops_data_sz * 100) / 45;
 639         big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 640         if (big_oops_buf) {
 641                 stream.workspace =  kmalloc(zlib_deflate_workspacesize(
 642                                         WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
 643                 if (!stream.workspace) {
 644                         pr_err("nvram: No memory for compression workspace; "
 645                                 "skipping compression of %s partition data\n",
 646                                 oops_log_partition.name);
 647                         kfree(big_oops_buf);
 648                         big_oops_buf = NULL;
 649                 }
 650         } else {
 651                 pr_err("No memory for uncompressed %s data; "
 652                         "skipping compression\n", oops_log_partition.name);
 653                 stream.workspace = NULL;
 654         }
 655
 656         rc = kmsg_dump_register(&nvram_kmsg_dumper);
 657         if (rc != 0) {
 658                 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
 659                 kfree(oops_buf);
 660                 kfree(big_oops_buf);
 661                 kfree(stream.workspace);
 662         }
 663 }
 664
 665 /*
 666  * This is our kmsg_dump callback, called after an oops or panic report
 667  * has been written to the printk buffer.  We want to capture as much
 668  * of the printk buffer as possible.  First, capture as much as we can
 669  * that we think will compress sufficiently to fit in the lnx,oops-log
 670  * partition.  If that's too much, go back and capture uncompressed text.
 671  */
 672 static void oops_to_nvram(struct kmsg_dumper *dumper,
 673                           enum kmsg_dump_reason reason)
 674 {
 675         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 676         static unsigned int oops_count = 0;
 677         static bool panicking = false;
 678         static DEFINE_SPINLOCK(lock);
 679         unsigned long flags;
 680         size_t text_len;
 681         unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 682         int rc = -1;
 683
 684         switch (reason) {
 685         case KMSG_DUMP_RESTART:
 686         case KMSG_DUMP_HALT:
 687         case KMSG_DUMP_POWEROFF:
 688                 /* These are almost always orderly shutdowns. */
 689                 return;
 690         case KMSG_DUMP_OOPS:
 691                 break;
 692         case KMSG_DUMP_PANIC:
 693                 panicking = true;
 694                 break;
 695         case KMSG_DUMP_EMERG:
 696                 if (panicking)
 697                         /* Panic report already captured. */
 698                         return;
 699                 break;
 700         default:
 701                 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
 702                        __func__, (int) reason);
 703                 return;
 704         }
 705
 706         if (clobbering_unread_rtas_event())
 707                 return;
 708
 709         if (!spin_trylock_irqsave(&lock, flags))
 710                 return;
 711
 712         if (big_oops_buf) {
 713                 kmsg_dump_get_buffer(dumper, false,
 714                                      big_oops_buf, big_oops_buf_sz, &text_len);
 715                 rc = zip_oops(text_len);
 716         }
 717         if (rc != 0) {
 718                 kmsg_dump_rewind(dumper);
 719                 kmsg_dump_get_buffer(dumper, false,
 720                                      oops_data, oops_data_sz, &text_len);
 721                 err_type = ERR_TYPE_KERNEL_PANIC;
 722                 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 723                 oops_hdr->report_length = cpu_to_be16(text_len);
 724                 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 725         }
 726
 727         (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
 728                 (int) (sizeof(*oops_hdr) + text_len), err_type,
 729                 ++oops_count);
 730
 731         spin_unlock_irqrestore(&lock, flags);
 732 }
 733
 734 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin)
 735 {
 736         int size;
 737
 738         if (ppc_md.nvram_size == NULL)
 739                 return -ENODEV;
 740         size = ppc_md.nvram_size();
 741
 742         switch (origin) {
 743         case 1:
 744                 offset += file->f_pos;
 745                 break;
 746         case 2:
 747                 offset += size;
 748                 break;
 749         }
 750         if (offset < 0)
 751                 return -EINVAL;
 752         file->f_pos = offset;
 753         return file->f_pos;
 754 }
 755
 756
 757 static ssize_t dev_nvram_read(struct file *file, char __user *buf,
 758                           size_t count, loff_t *ppos)
 759 {
 760         ssize_t ret;
 761         char *tmp = NULL;
 762         ssize_t size;
 763
 764         if (!ppc_md.nvram_size) {
 765                 ret = -ENODEV;
 766                 goto out;
 767         }
 768
 769         size = ppc_md.nvram_size();
 770         if (size < 0) {
 771                 ret = size;
 772                 goto out;
 773         }
 774
 775         if (*ppos >= size) {
 776                 ret = 0;
 777                 goto out;
 778         }
 779
 780         count = min_t(size_t, count, size - *ppos);
 781         count = min(count, PAGE_SIZE);
 782
 783         tmp = kmalloc(count, GFP_KERNEL);
 784         if (!tmp) {
 785                 ret = -ENOMEM;
 786                 goto out;
 787         }
 788
 789         ret = ppc_md.nvram_read(tmp, count, ppos);
 790         if (ret <= 0)
 791                 goto out;
 792
 793         if (copy_to_user(buf, tmp, ret))
 794                 ret = -EFAULT;
 795
 796 out:
 797         kfree(tmp);
 798         return ret;
 799
 800 }
 801
 802 static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
 803                           size_t count, loff_t *ppos)
 804 {
 805         ssize_t ret;
 806         char *tmp = NULL;
 807         ssize_t size;
 808
 809         ret = -ENODEV;
 810         if (!ppc_md.nvram_size)
 811                 goto out;
 812
 813         ret = 0;
 814         size = ppc_md.nvram_size();
 815         if (*ppos >= size || size < 0)
 816                 goto out;
 817
 818         count = min_t(size_t, count, size - *ppos);
 819         count = min(count, PAGE_SIZE);
 820
 821         ret = -ENOMEM;
 822         tmp = kmalloc(count, GFP_KERNEL);
 823         if (!tmp)
 824                 goto out;
 825
 826         ret = -EFAULT;
 827         if (copy_from_user(tmp, buf, count))
 828                 goto out;
 829
 830         ret = ppc_md.nvram_write(tmp, count, ppos);
 831
 832 out:
 833         kfree(tmp);
 834         return ret;
 835
 836 }
 837
 838 static long dev_nvram_ioctl(struct file *file, unsigned int cmd,
 839                             unsigned long arg)
 840 {
 841         switch(cmd) {
 842 #ifdef CONFIG_PPC_PMAC
 843         case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
 844                 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
 845         case IOC_NVRAM_GET_OFFSET: {
 846                 int part, offset;
 847
 848                 if (!machine_is(powermac))
 849                         return -EINVAL;
 850                 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
 851                         return -EFAULT;
 852                 if (part < pmac_nvram_OF || part > pmac_nvram_NR)
 853                         return -EINVAL;
 854                 offset = pmac_get_partition(part);
 855                 if (offset < 0)
 856                         return offset;
 857                 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
 858                         return -EFAULT;
 859                 return 0;
 860         }
 861 #endif /* CONFIG_PPC_PMAC */
 862         default:
 863                 return -EINVAL;
 864         }
 865 }
 866
 867 const struct file_operations nvram_fops = {
 868         .owner          = THIS_MODULE,
 869         .llseek         = dev_nvram_llseek,
 870         .read           = dev_nvram_read,
 871         .write          = dev_nvram_write,
 872         .unlocked_ioctl = dev_nvram_ioctl,
 873 };
 874
 875 static struct miscdevice nvram_dev = {
 876         NVRAM_MINOR,
 877         "nvram",
 878         &nvram_fops
 879 };
 880
 881
 882 #ifdef DEBUG_NVRAM
 883 static void __init nvram_print_partitions(char * label)
 884 {
 885         struct nvram_partition * tmp_part;
 886
 887         printk(KERN_WARNING "--------%s---------\n", label);
 888         printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
 889         list_for_each_entry(tmp_part, &nvram_partitions, partition) {
 890                 printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%12.12s\n",
 891                        tmp_part->index, tmp_part->header.signature,
 892                        tmp_part->header.checksum, tmp_part->header.length,
 893                        tmp_part->header.name);
 894         }
 895 }
 896 #endif
 897
 898
 899 static int __init nvram_write_header(struct nvram_partition * part)
 900 {
 901         loff_t tmp_index;
 902         int rc;
 903         struct nvram_header phead;
 904
 905         memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
 906         phead.length = cpu_to_be16(phead.length);
 907
 908         tmp_index = part->index;
 909         rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
 910
 911         return rc;
 912 }
 913
 914
 915 static unsigned char __init nvram_checksum(struct nvram_header *p)
 916 {
 917         unsigned int c_sum, c_sum2;
 918         unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
 919         c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
 920
 921         /* The sum may have spilled into the 3rd byte.  Fold it back. */
 922         c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
 923         /* The sum cannot exceed 2 bytes.  Fold it into a checksum */
 924         c_sum2 = (c_sum >> 8) + (c_sum << 8);
 925         c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
 926         return c_sum;
 927 }
 928
 929 /*
 930  * Per the criteria passed via nvram_remove_partition(), should this
 931  * partition be removed?  1=remove, 0=keep
 932  */
 933 static int nvram_can_remove_partition(struct nvram_partition *part,
 934                 const char *name, int sig, const char *exceptions[])
 935 {
 936         if (part->header.signature != sig)
 937                 return 0;
 938         if (name) {
 939                 if (strncmp(name, part->header.name, 12))
 940                         return 0;
 941         } else if (exceptions) {
 942                 const char **except;
 943                 for (except = exceptions; *except; except++) {
 944                         if (!strncmp(*except, part->header.name, 12))
 945                                 return 0;
 946                 }
 947         }
 948         return 1;
 949 }
 950
 951 /**
 952  * nvram_remove_partition - Remove one or more partitions in nvram
 953  * @name: name of the partition to remove, or NULL for a
 954  *        signature only match
 955  * @sig: signature of the partition(s) to remove
 956  * @exceptions: When removing all partitions with a matching signature,
 957  *        leave these alone.
 958  */
 959
 960 int __init nvram_remove_partition(const char *name, int sig,
 961                                                 const char *exceptions[])
 962 {
 963         struct nvram_partition *part, *prev, *tmp;
 964         int rc;
 965
 966         list_for_each_entry(part, &nvram_partitions, partition) {
 967                 if (!nvram_can_remove_partition(part, name, sig, exceptions))
 968                         continue;
 969
 970                 /* Make partition a free partition */
 971                 part->header.signature = NVRAM_SIG_FREE;
 972                 strncpy(part->header.name, "wwwwwwwwwwww", 12);
 973                 part->header.checksum = nvram_checksum(&part->header);
 974                 rc = nvram_write_header(part);
 975                 if (rc <= 0) {
 976                         printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 977                         return rc;
 978                 }
 979         }
 980
 981         /* Merge contiguous ones */
 982         prev = NULL;
 983         list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
 984                 if (part->header.signature != NVRAM_SIG_FREE) {
 985                         prev = NULL;
 986                         continue;
 987                 }
 988                 if (prev) {
 989                         prev->header.length += part->header.length;
 990                         prev->header.checksum = nvram_checksum(&part->header);
 991                         rc = nvram_write_header(part);
 992                         if (rc <= 0) {
 993                                 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 994                                 return rc;
 995                         }
 996                         list_del(&part->partition);
 997                         kfree(part);
 998                 } else
 999                         prev = part;
1000         }
1001
1002         return 0;
1003 }
1004
1005 /**
1006  * nvram_create_partition - Create a partition in nvram
1007  * @name: name of the partition to create
1008  * @sig: signature of the partition to create
1009  * @req_size: size of data to allocate in bytes
1010  * @min_size: minimum acceptable size (0 means req_size)
1011  *
1012  * Returns a negative error code or a positive nvram index
1013  * of the beginning of the data area of the newly created
1014  * partition. If you provided a min_size smaller than req_size
1015  * you need to query for the actual size yourself after the
1016  * call using nvram_partition_get_size().
1017  */
1018 loff_t __init nvram_create_partition(const char *name, int sig,
1019                                      int req_size, int min_size)
1020 {
1021         struct nvram_partition *part;
1022         struct nvram_partition *new_part;
1023         struct nvram_partition *free_part = NULL;
1024         static char nv_init_vals[16];
1025         loff_t tmp_index;
1026         long size = 0;
1027         int rc;
1028
1029         /* Convert sizes from bytes to blocks */
1030         req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
1031         min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
1032
1033         /* If no minimum size specified, make it the same as the
1034          * requested size
1035          */
1036         if (min_size == 0)
1037                 min_size = req_size;
1038         if (min_size > req_size)
1039                 return -EINVAL;
1040
1041         /* Now add one block to each for the header */
1042         req_size += 1;
1043         min_size += 1;
1044
1045         /* Find a free partition that will give us the maximum needed size
1046            If can't find one that will give us the minimum size needed */
1047         list_for_each_entry(part, &nvram_partitions, partition) {
1048                 if (part->header.signature != NVRAM_SIG_FREE)
1049                         continue;
1050
1051                 if (part->header.length >= req_size) {
1052                         size = req_size;
1053                         free_part = part;
1054                         break;
1055                 }
1056                 if (part->header.length > size &&
1057                     part->header.length >= min_size) {
1058                         size = part->header.length;
1059                         free_part = part;
1060                 }
1061         }
1062         if (!size)
1063                 return -ENOSPC;
1064
1065         /* Create our OS partition */
1066         new_part = kmalloc(sizeof(*new_part), GFP_KERNEL);
1067         if (!new_part) {
1068                 pr_err("nvram_create_os_partition: kmalloc failed\n");
1069                 return -ENOMEM;
1070         }
1071
1072         new_part->index = free_part->index;
1073         new_part->header.signature = sig;
1074         new_part->header.length = size;
1075         strncpy(new_part->header.name, name, 12);
1076         new_part->header.checksum = nvram_checksum(&new_part->header);
1077
1078         rc = nvram_write_header(new_part);
1079         if (rc <= 0) {
1080                 pr_err("nvram_create_os_partition: nvram_write_header "
1081                        "failed (%d)\n", rc);
1082                 return rc;
1083         }
1084         list_add_tail(&new_part->partition, &free_part->partition);
1085
1086         /* Adjust or remove the partition we stole the space from */
1087         if (free_part->header.length > size) {
1088                 free_part->index += size * NVRAM_BLOCK_LEN;
1089                 free_part->header.length -= size;
1090                 free_part->header.checksum = nvram_checksum(&free_part->header);
1091                 rc = nvram_write_header(free_part);
1092                 if (rc <= 0) {
1093                         pr_err("nvram_create_os_partition: nvram_write_header "
1094                                "failed (%d)\n", rc);
1095                         return rc;
1096                 }
1097         } else {
1098                 list_del(&free_part->partition);
1099                 kfree(free_part);
1100         }
1101
1102         /* Clear the new partition */
1103         for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
1104              tmp_index <  ((size - 1) * NVRAM_BLOCK_LEN);
1105              tmp_index += NVRAM_BLOCK_LEN) {
1106                 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
1107                 if (rc <= 0) {
1108                         pr_err("nvram_create_partition: nvram_write failed (%d)\n", rc);
1109                         return rc;
1110                 }
1111         }
1112
1113         return new_part->index + NVRAM_HEADER_LEN;
1114 }
1115
1116 /**
1117  * nvram_get_partition_size - Get the data size of an nvram partition
1118  * @data_index: This is the offset of the start of the data of
1119  *              the partition. The same value that is returned by
1120  *              nvram_create_partition().
1121  */
1122 int nvram_get_partition_size(loff_t data_index)
1123 {
1124         struct nvram_partition *part;
1125
1126         list_for_each_entry(part, &nvram_partitions, partition) {
1127                 if (part->index + NVRAM_HEADER_LEN == data_index)
1128                         return (part->header.length - 1) * NVRAM_BLOCK_LEN;
1129         }
1130         return -1;
1131 }
1132
1133
1134 /**
1135  * nvram_find_partition - Find an nvram partition by signature and name
1136  * @name: Name of the partition or NULL for any name
1137  * @sig: Signature to test against
1138  * @out_size: if non-NULL, returns the size of the data part of the partition
1139  */
1140 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
1141 {
1142         struct nvram_partition *p;
1143
1144         list_for_each_entry(p, &nvram_partitions, partition) {
1145                 if (p->header.signature == sig &&
1146                     (!name || !strncmp(p->header.name, name, 12))) {
1147                         if (out_size)
1148                                 *out_size = (p->header.length - 1) *
1149                                         NVRAM_BLOCK_LEN;
1150                         return p->index + NVRAM_HEADER_LEN;
1151                 }
1152         }
1153         return 0;
1154 }
1155
1156 int __init nvram_scan_partitions(void)
1157 {
1158         loff_t cur_index = 0;
1159         struct nvram_header phead;
1160         struct nvram_partition * tmp_part;
1161         unsigned char c_sum;
1162         char * header;
1163         int total_size;
1164         int err;
1165
1166         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1167                 return -ENODEV;
1168         total_size = ppc_md.nvram_size();
1169
1170         header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
1171         if (!header) {
1172                 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
1173                 return -ENOMEM;
1174         }
1175
1176         while (cur_index < total_size) {
1177
1178                 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
1179                 if (err != NVRAM_HEADER_LEN) {
1180                         printk(KERN_ERR "nvram_scan_partitions: Error parsing "
1181                                "nvram partitions\n");
1182                         goto out;
1183                 }
1184
1185                 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
1186
1187                 memcpy(&phead, header, NVRAM_HEADER_LEN);
1188
1189                 phead.length = be16_to_cpu(phead.length);
1190
1191                 err = 0;
1192                 c_sum = nvram_checksum(&phead);
1193                 if (c_sum != phead.checksum) {
1194                         printk(KERN_WARNING "WARNING: nvram partition checksum"
1195                                " was %02x, should be %02x!\n",
1196                                phead.checksum, c_sum);
1197                         printk(KERN_WARNING "Terminating nvram partition scan\n");
1198                         goto out;
1199                 }
1200                 if (!phead.length) {
1201                         printk(KERN_WARNING "WARNING: nvram corruption "
1202                                "detected: 0-length partition\n");
1203                         goto out;
1204                 }
1205                 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL);
1206                 err = -ENOMEM;
1207                 if (!tmp_part) {
1208                         printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
1209                         goto out;
1210                 }
1211
1212                 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
1213                 tmp_part->index = cur_index;
1214                 list_add_tail(&tmp_part->partition, &nvram_partitions);
1215
1216                 cur_index += phead.length * NVRAM_BLOCK_LEN;
1217         }
1218         err = 0;
1219
1220 #ifdef DEBUG_NVRAM
1221         nvram_print_partitions("NVRAM Partitions");
1222 #endif
1223
1224  out:
1225         kfree(header);
1226         return err;
1227 }
1228
1229 static int __init nvram_init(void)
1230 {
1231         int rc;
1232
1233         BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
1234
1235         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
1236                 return  -ENODEV;
1237
1238         rc = misc_register(&nvram_dev);
1239         if (rc != 0) {
1240                 printk(KERN_ERR "nvram_init: failed to register device\n");
1241                 return rc;
1242         }
1243
1244         return rc;
1245 }
1246
1247 static void __exit nvram_cleanup(void)
1248 {
1249         misc_deregister( &nvram_dev );
1250 }
1251
1252 module_init(nvram_init);
1253 module_exit(nvram_cleanup);
1254 MODULE_LICENSE("GPL");