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