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