arch/powerpc/kernel/nvram_64.c

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