arch/powerpc/platforms/pseries/nvram.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
  14
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/init.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/slab.h>
  20 #include <linux/kmsg_dump.h>
  21 #include <linux/pstore.h>
  22 #include <linux/ctype.h>
  23 #include <linux/zlib.h>
  24 #include <asm/uaccess.h>
  25 #include <asm/nvram.h>
  26 #include <asm/rtas.h>
  27 #include <asm/prom.h>
  28 #include <asm/machdep.h>
  29
  30 /* Max bytes to read/write in one go */
  31 #define NVRW_CNT 0x20
  32
  33 /*
  34  * Set oops header version to distingush between old and new format header.
  35  * lnx,oops-log partition max size is 4000, header version > 4000 will
  36  * help in identifying new header.
  37  */
  38 #define OOPS_HDR_VERSION 5000
  39
  40 static unsigned int nvram_size;
  41 static int nvram_fetch, nvram_store;
  42 static char nvram_buf[NVRW_CNT];        /* assume this is in the first 4GB */
  43 static DEFINE_SPINLOCK(nvram_lock);
  44
  45 struct err_log_info {
  46         int error_type;
  47         unsigned int seq_num;
  48 };
  49
  50 struct nvram_os_partition {
  51         const char *name;
  52         int req_size;   /* desired size, in bytes */
  53         int min_size;   /* minimum acceptable size (0 means req_size) */
  54         long size;      /* size of data portion (excluding err_log_info) */
  55         long index;     /* offset of data portion of partition */
  56         bool os_partition; /* partition initialized by OS, not FW */
  57 };
  58
  59 static struct nvram_os_partition rtas_log_partition = {
  60         .name = "ibm,rtas-log",
  61         .req_size = 2079,
  62         .min_size = 1055,
  63         .index = -1,
  64         .os_partition = true
  65 };
  66
  67 static struct nvram_os_partition oops_log_partition = {
  68         .name = "lnx,oops-log",
  69         .req_size = 4000,
  70         .min_size = 2000,
  71         .index = -1,
  72         .os_partition = true
  73 };
  74
  75 static const char *pseries_nvram_os_partitions[] = {
  76         "ibm,rtas-log",
  77         "lnx,oops-log",
  78         NULL
  79 };
  80
  81 struct oops_log_info {
  82         u16 version;
  83         u16 report_length;
  84         u64 timestamp;
  85 } __attribute__((packed));
  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 /* See clobbering_unread_rtas_event() */
  95 #define NVRAM_RTAS_READ_TIMEOUT 5               /* seconds */
  96 static unsigned long last_unread_rtas_event;    /* timestamp */
  97
  98 /*
  99  * For capturing and compressing an oops or panic report...
 100
 101  * big_oops_buf[] holds the uncompressed text we're capturing.
 102  *
 103  * oops_buf[] holds the compressed text, preceded by a oops header.
 104  * oops header has u16 holding the version of oops header (to differentiate
 105  * between old and new format header) followed by u16 holding the length of
 106  * the compressed* text (*Or uncompressed, if compression fails.) and u64
 107  * holding the timestamp. oops_buf[] gets written to NVRAM.
 108  *
 109  * oops_log_info points to the header. oops_data points to the compressed text.
 110  *
 111  * +- oops_buf
 112  * |                                   +- oops_data
 113  * v                                   v
 114  * +-----------+-----------+-----------+------------------------+
 115  * | version   | length    | timestamp | text                   |
 116  * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
 117  * +-----------+-----------+-----------+------------------------+
 118  * ^
 119  * +- oops_log_info
 120  *
 121  * We preallocate these buffers during init to avoid kmalloc during oops/panic.
 122  */
 123 static size_t big_oops_buf_sz;
 124 static char *big_oops_buf, *oops_buf;
 125 static char *oops_data;
 126 static size_t oops_data_sz;
 127
 128 /* Compression parameters */
 129 #define COMPR_LEVEL 6
 130 #define WINDOW_BITS 12
 131 #define MEM_LEVEL 4
 132 static struct z_stream_s stream;
 133
 134 #ifdef CONFIG_PSTORE
 135 static struct nvram_os_partition of_config_partition = {
 136         .name = "of-config",
 137         .index = -1,
 138         .os_partition = false
 139 };
 140
 141 static struct nvram_os_partition common_partition = {
 142         .name = "common",
 143         .index = -1,
 144         .os_partition = false
 145 };
 146
 147 static enum pstore_type_id nvram_type_ids[] = {
 148         PSTORE_TYPE_DMESG,
 149         PSTORE_TYPE_PPC_RTAS,
 150         PSTORE_TYPE_PPC_OF,
 151         PSTORE_TYPE_PPC_COMMON,
 152         -1
 153 };
 154 static int read_type;
 155 static unsigned long last_rtas_event;
 156 #endif
 157
 158 static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
 159 {
 160         unsigned int i;
 161         unsigned long len;
 162         int done;
 163         unsigned long flags;
 164         char *p = buf;
 165
 166
 167         if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
 168                 return -ENODEV;
 169
 170         if (*index >= nvram_size)
 171                 return 0;
 172
 173         i = *index;
 174         if (i + count > nvram_size)
 175                 count = nvram_size - i;
 176
 177         spin_lock_irqsave(&nvram_lock, flags);
 178
 179         for (; count != 0; count -= len) {
 180                 len = count;
 181                 if (len > NVRW_CNT)
 182                         len = NVRW_CNT;
 183
 184                 if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
 185                                len) != 0) || len != done) {
 186                         spin_unlock_irqrestore(&nvram_lock, flags);
 187                         return -EIO;
 188                 }
 189
 190                 memcpy(p, nvram_buf, len);
 191
 192                 p += len;
 193                 i += len;
 194         }
 195
 196         spin_unlock_irqrestore(&nvram_lock, flags);
 197
 198         *index = i;
 199         return p - buf;
 200 }
 201
 202 static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
 203 {
 204         unsigned int i;
 205         unsigned long len;
 206         int done;
 207         unsigned long flags;
 208         const char *p = buf;
 209
 210         if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
 211                 return -ENODEV;
 212
 213         if (*index >= nvram_size)
 214                 return 0;
 215
 216         i = *index;
 217         if (i + count > nvram_size)
 218                 count = nvram_size - i;
 219
 220         spin_lock_irqsave(&nvram_lock, flags);
 221
 222         for (; count != 0; count -= len) {
 223                 len = count;
 224                 if (len > NVRW_CNT)
 225                         len = NVRW_CNT;
 226
 227                 memcpy(nvram_buf, p, len);
 228
 229                 if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
 230                                len) != 0) || len != done) {
 231                         spin_unlock_irqrestore(&nvram_lock, flags);
 232                         return -EIO;
 233                 }
 234
 235                 p += len;
 236                 i += len;
 237         }
 238         spin_unlock_irqrestore(&nvram_lock, flags);
 239
 240         *index = i;
 241         return p - buf;
 242 }
 243
 244 static ssize_t pSeries_nvram_get_size(void)
 245 {
 246         return nvram_size ? nvram_size : -ENODEV;
 247 }
 248
 249
 250 /* nvram_write_os_partition, nvram_write_error_log
 251  *
 252  * We need to buffer the error logs into nvram to ensure that we have
 253  * the failure information to decode.  If we have a severe error there
 254  * is no way to guarantee that the OS or the machine is in a state to
 255  * get back to user land and write the error to disk.  For example if
 256  * the SCSI device driver causes a Machine Check by writing to a bad
 257  * IO address, there is no way of guaranteeing that the device driver
 258  * is in any state that is would also be able to write the error data
 259  * captured to disk, thus we buffer it in NVRAM for analysis on the
 260  * next boot.
 261  *
 262  * In NVRAM the partition containing the error log buffer will looks like:
 263  * Header (in bytes):
 264  * +-----------+----------+--------+------------+------------------+
 265  * | signature | checksum | length | name       | data             |
 266  * |0          |1         |2      3|4         15|16        length-1|
 267  * +-----------+----------+--------+------------+------------------+
 268  *
 269  * The 'data' section would look like (in bytes):
 270  * +--------------+------------+-----------------------------------+
 271  * | event_logged | sequence # | error log                         |
 272  * |0            3|4          7|8                  error_log_size-1|
 273  * +--------------+------------+-----------------------------------+
 274  *
 275  * event_logged: 0 if event has not been logged to syslog, 1 if it has
 276  * sequence #: The unique sequence # for each event. (until it wraps)
 277  * error log: The error log from event_scan
 278  */
 279 int nvram_write_os_partition(struct nvram_os_partition *part, char * buff,
 280                 int length, unsigned int err_type, unsigned int error_log_cnt)
 281 {
 282         int rc;
 283         loff_t tmp_index;
 284         struct err_log_info info;
 285
 286         if (part->index == -1) {
 287                 return -ESPIPE;
 288         }
 289
 290         if (length > part->size) {
 291                 length = part->size;
 292         }
 293
 294         info.error_type = err_type;
 295         info.seq_num = error_log_cnt;
 296
 297         tmp_index = part->index;
 298
 299         rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index);
 300         if (rc <= 0) {
 301                 pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc);
 302                 return rc;
 303         }
 304
 305         rc = ppc_md.nvram_write(buff, length, &tmp_index);
 306         if (rc <= 0) {
 307                 pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc);
 308                 return rc;
 309         }
 310
 311         return 0;
 312 }
 313
 314 int nvram_write_error_log(char * buff, int length,
 315                           unsigned int err_type, unsigned int error_log_cnt)
 316 {
 317         int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
 318                                                 err_type, error_log_cnt);
 319         if (!rc) {
 320                 last_unread_rtas_event = get_seconds();
 321 #ifdef CONFIG_PSTORE
 322                 last_rtas_event = get_seconds();
 323 #endif
 324         }
 325
 326         return rc;
 327 }
 328
 329 /* nvram_read_partition
 330  *
 331  * Reads nvram partition for at most 'length'
 332  */
 333 int nvram_read_partition(struct nvram_os_partition *part, char *buff,
 334                         int length, unsigned int *err_type,
 335                         unsigned int *error_log_cnt)
 336 {
 337         int rc;
 338         loff_t tmp_index;
 339         struct err_log_info info;
 340
 341         if (part->index == -1)
 342                 return -1;
 343
 344         if (length > part->size)
 345                 length = part->size;
 346
 347         tmp_index = part->index;
 348
 349         if (part->os_partition) {
 350                 rc = ppc_md.nvram_read((char *)&info,
 351                                         sizeof(struct err_log_info),
 352                                         &tmp_index);
 353                 if (rc <= 0) {
 354                         pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__,
 355                                                                         rc);
 356                         return rc;
 357                 }
 358         }
 359
 360         rc = ppc_md.nvram_read(buff, length, &tmp_index);
 361         if (rc <= 0) {
 362                 pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__, rc);
 363                 return rc;
 364         }
 365
 366         if (part->os_partition) {
 367                 *error_log_cnt = info.seq_num;
 368                 *err_type = info.error_type;
 369         }
 370
 371         return 0;
 372 }
 373
 374 /* nvram_read_error_log
 375  *
 376  * Reads nvram for error log for at most 'length'
 377  */
 378 int nvram_read_error_log(char *buff, int length,
 379                         unsigned int *err_type, unsigned int *error_log_cnt)
 380 {
 381         return nvram_read_partition(&rtas_log_partition, buff, length,
 382                                                 err_type, error_log_cnt);
 383 }
 384
 385 /* This doesn't actually zero anything, but it sets the event_logged
 386  * word to tell that this event is safely in syslog.
 387  */
 388 int nvram_clear_error_log(void)
 389 {
 390         loff_t tmp_index;
 391         int clear_word = ERR_FLAG_ALREADY_LOGGED;
 392         int rc;
 393
 394         if (rtas_log_partition.index == -1)
 395                 return -1;
 396
 397         tmp_index = rtas_log_partition.index;
 398
 399         rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
 400         if (rc <= 0) {
 401                 printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
 402                 return rc;
 403         }
 404         last_unread_rtas_event = 0;
 405
 406         return 0;
 407 }
 408
 409 /* pseries_nvram_init_os_partition
 410  *
 411  * This sets up a partition with an "OS" signature.
 412  *
 413  * The general strategy is the following:
 414  * 1.) If a partition with the indicated name already exists...
 415  *      - If it's large enough, use it.
 416  *      - Otherwise, recycle it and keep going.
 417  * 2.) Search for a free partition that is large enough.
 418  * 3.) If there's not a free partition large enough, recycle any obsolete
 419  * OS partitions and try again.
 420  * 4.) Will first try getting a chunk that will satisfy the requested size.
 421  * 5.) If a chunk of the requested size cannot be allocated, then try finding
 422  * a chunk that will satisfy the minum needed.
 423  *
 424  * Returns 0 on success, else -1.
 425  */
 426 static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
 427                                                                         *part)
 428 {
 429         loff_t p;
 430         int size;
 431
 432         /* Scan nvram for partitions */
 433         nvram_scan_partitions();
 434
 435         /* Look for ours */
 436         p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
 437
 438         /* Found one but too small, remove it */
 439         if (p && size < part->min_size) {
 440                 pr_info("nvram: Found too small %s partition,"
 441                                         " removing it...\n", part->name);
 442                 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
 443                 p = 0;
 444         }
 445
 446         /* Create one if we didn't find */
 447         if (!p) {
 448                 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 449                                         part->req_size, part->min_size);
 450                 if (p == -ENOSPC) {
 451                         pr_info("nvram: No room to create %s partition, "
 452                                 "deleting any obsolete OS partitions...\n",
 453                                 part->name);
 454                         nvram_remove_partition(NULL, NVRAM_SIG_OS,
 455                                                 pseries_nvram_os_partitions);
 456                         p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 457                                         part->req_size, part->min_size);
 458                 }
 459         }
 460
 461         if (p <= 0) {
 462                 pr_err("nvram: Failed to find or create %s"
 463                        " partition, err %d\n", part->name, (int)p);
 464                 return -1;
 465         }
 466
 467         part->index = p;
 468         part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
 469
 470         return 0;
 471 }
 472
 473 /*
 474  * Are we using the ibm,rtas-log for oops/panic reports?  And if so,
 475  * would logging this oops/panic overwrite an RTAS event that rtas_errd
 476  * hasn't had a chance to read and process?  Return 1 if so, else 0.
 477  *
 478  * We assume that if rtas_errd hasn't read the RTAS event in
 479  * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to.
 480  */
 481 static int clobbering_unread_rtas_event(void)
 482 {
 483         return (oops_log_partition.index == rtas_log_partition.index
 484                 && last_unread_rtas_event
 485                 && get_seconds() - last_unread_rtas_event <=
 486                                                 NVRAM_RTAS_READ_TIMEOUT);
 487 }
 488
 489 /* Derived from logfs_compress() */
 490 static int nvram_compress(const void *in, void *out, size_t inlen,
 491                                                         size_t outlen)
 492 {
 493         int err, ret;
 494
 495         ret = -EIO;
 496         err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
 497                                                 MEM_LEVEL, Z_DEFAULT_STRATEGY);
 498         if (err != Z_OK)
 499                 goto error;
 500
 501         stream.next_in = in;
 502         stream.avail_in = inlen;
 503         stream.total_in = 0;
 504         stream.next_out = out;
 505         stream.avail_out = outlen;
 506         stream.total_out = 0;
 507
 508         err = zlib_deflate(&stream, Z_FINISH);
 509         if (err != Z_STREAM_END)
 510                 goto error;
 511
 512         err = zlib_deflateEnd(&stream);
 513         if (err != Z_OK)
 514                 goto error;
 515
 516         if (stream.total_out >= stream.total_in)
 517                 goto error;
 518
 519         ret = stream.total_out;
 520 error:
 521         return ret;
 522 }
 523
 524 /* Compress the text from big_oops_buf into oops_buf. */
 525 static int zip_oops(size_t text_len)
 526 {
 527         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 528         int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
 529                                                                 oops_data_sz);
 530         if (zipped_len < 0) {
 531                 pr_err("nvram: compression failed; returned %d\n", zipped_len);
 532                 pr_err("nvram: logging uncompressed oops/panic report\n");
 533                 return -1;
 534         }
 535         oops_hdr->version = OOPS_HDR_VERSION;
 536         oops_hdr->report_length = (u16) zipped_len;
 537         oops_hdr->timestamp = get_seconds();
 538         return 0;
 539 }
 540
 541 #ifdef CONFIG_PSTORE
 542 /* Derived from logfs_uncompress */
 543 int nvram_decompress(void *in, void *out, size_t inlen, size_t outlen)
 544 {
 545         int err, ret;
 546
 547         ret = -EIO;
 548         err = zlib_inflateInit(&stream);
 549         if (err != Z_OK)
 550                 goto error;
 551
 552         stream.next_in = in;
 553         stream.avail_in = inlen;
 554         stream.total_in = 0;
 555         stream.next_out = out;
 556         stream.avail_out = outlen;
 557         stream.total_out = 0;
 558
 559         err = zlib_inflate(&stream, Z_FINISH);
 560         if (err != Z_STREAM_END)
 561                 goto error;
 562
 563         err = zlib_inflateEnd(&stream);
 564         if (err != Z_OK)
 565                 goto error;
 566
 567         ret = stream.total_out;
 568 error:
 569         return ret;
 570 }
 571
 572 static int unzip_oops(char *oops_buf, char *big_buf)
 573 {
 574         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 575         u64 timestamp = oops_hdr->timestamp;
 576         char *big_oops_data = NULL;
 577         char *oops_data_buf = NULL;
 578         size_t big_oops_data_sz;
 579         int unzipped_len;
 580
 581         big_oops_data = big_buf + sizeof(struct oops_log_info);
 582         big_oops_data_sz = big_oops_buf_sz - sizeof(struct oops_log_info);
 583         oops_data_buf = oops_buf + sizeof(struct oops_log_info);
 584
 585         unzipped_len = nvram_decompress(oops_data_buf, big_oops_data,
 586                                         oops_hdr->report_length,
 587                                         big_oops_data_sz);
 588
 589         if (unzipped_len < 0) {
 590                 pr_err("nvram: decompression failed; returned %d\n",
 591                                                                 unzipped_len);
 592                 return -1;
 593         }
 594         oops_hdr = (struct oops_log_info *)big_buf;
 595         oops_hdr->version = OOPS_HDR_VERSION;
 596         oops_hdr->report_length = (u16) unzipped_len;
 597         oops_hdr->timestamp = timestamp;
 598         return 0;
 599 }
 600
 601 static int nvram_pstore_open(struct pstore_info *psi)
 602 {
 603         /* Reset the iterator to start reading partitions again */
 604         read_type = -1;
 605         return 0;
 606 }
 607
 608 /**
 609  * nvram_pstore_write - pstore write callback for nvram
 610  * @type:               Type of message logged
 611  * @reason:             reason behind dump (oops/panic)
 612  * @id:                 identifier to indicate the write performed
 613  * @part:               pstore writes data to registered buffer in parts,
 614  *                      part number will indicate the same.
 615  * @count:              Indicates oops count
 616  * @hsize:              Size of header added by pstore
 617  * @size:               number of bytes written to the registered buffer
 618  * @psi:                registered pstore_info structure
 619  *
 620  * Called by pstore_dump() when an oops or panic report is logged in the
 621  * printk buffer.
 622  * Returns 0 on successful write.
 623  */
 624 static int nvram_pstore_write(enum pstore_type_id type,
 625                                 enum kmsg_dump_reason reason,
 626                                 u64 *id, unsigned int part, int count,
 627                                 size_t hsize, size_t size,
 628                                 struct pstore_info *psi)
 629 {
 630         int rc;
 631         unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
 632         struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
 633
 634         /* part 1 has the recent messages from printk buffer */
 635         if (part > 1 || type != PSTORE_TYPE_DMESG ||
 636                                 clobbering_unread_rtas_event())
 637                 return -1;
 638
 639         oops_hdr->version = OOPS_HDR_VERSION;
 640         oops_hdr->report_length = (u16) size;
 641         oops_hdr->timestamp = get_seconds();
 642
 643         if (big_oops_buf) {
 644                 rc = zip_oops(size);
 645                 /*
 646                  * If compression fails copy recent log messages from
 647                  * big_oops_buf to oops_data.
 648                  */
 649                 if (rc != 0) {
 650                         size_t diff = size - oops_data_sz + hsize;
 651
 652                         if (size > oops_data_sz) {
 653                                 memcpy(oops_data, big_oops_buf, hsize);
 654                                 memcpy(oops_data + hsize, big_oops_buf + diff,
 655                                         oops_data_sz - hsize);
 656
 657                                 oops_hdr->report_length = (u16) oops_data_sz;
 658                         } else
 659                                 memcpy(oops_data, big_oops_buf, size);
 660                 } else
 661                         err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 662         }
 663
 664         rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
 665                 (int) (sizeof(*oops_hdr) + oops_hdr->report_length), err_type,
 666                 count);
 667
 668         if (rc != 0)
 669                 return rc;
 670
 671         *id = part;
 672         return 0;
 673 }
 674
 675 /*
 676  * Reads the oops/panic report, rtas, of-config and common partition.
 677  * Returns the length of the data we read from each partition.
 678  * Returns 0 if we've been called before.
 679  */
 680 static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
 681                                 int *count, struct timespec *time, char **buf,
 682                                 struct pstore_info *psi)
 683 {
 684         struct oops_log_info *oops_hdr;
 685         unsigned int err_type, id_no, size = 0;
 686         struct nvram_os_partition *part = NULL;
 687         char *buff = NULL, *big_buff = NULL;
 688         int rc, sig = 0;
 689         loff_t p;
 690
 691 read_partition:
 692         read_type++;
 693
 694         switch (nvram_type_ids[read_type]) {
 695         case PSTORE_TYPE_DMESG:
 696                 part = &oops_log_partition;
 697                 *type = PSTORE_TYPE_DMESG;
 698                 break;
 699         case PSTORE_TYPE_PPC_RTAS:
 700                 part = &rtas_log_partition;
 701                 *type = PSTORE_TYPE_PPC_RTAS;
 702                 time->tv_sec = last_rtas_event;
 703                 time->tv_nsec = 0;
 704                 break;
 705         case PSTORE_TYPE_PPC_OF:
 706                 sig = NVRAM_SIG_OF;
 707                 part = &of_config_partition;
 708                 *type = PSTORE_TYPE_PPC_OF;
 709                 *id = PSTORE_TYPE_PPC_OF;
 710                 time->tv_sec = 0;
 711                 time->tv_nsec = 0;
 712                 break;
 713         case PSTORE_TYPE_PPC_COMMON:
 714                 sig = NVRAM_SIG_SYS;
 715                 part = &common_partition;
 716                 *type = PSTORE_TYPE_PPC_COMMON;
 717                 *id = PSTORE_TYPE_PPC_COMMON;
 718                 time->tv_sec = 0;
 719                 time->tv_nsec = 0;
 720                 break;
 721         default:
 722                 return 0;
 723         }
 724
 725         if (!part->os_partition) {
 726                 p = nvram_find_partition(part->name, sig, &size);
 727                 if (p <= 0) {
 728                         pr_err("nvram: Failed to find partition %s, "
 729                                 "err %d\n", part->name, (int)p);
 730                         return 0;
 731                 }
 732                 part->index = p;
 733                 part->size = size;
 734         }
 735
 736         buff = kmalloc(part->size, GFP_KERNEL);
 737
 738         if (!buff)
 739                 return -ENOMEM;
 740
 741         if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
 742                 kfree(buff);
 743                 return 0;
 744         }
 745
 746         *count = 0;
 747
 748         if (part->os_partition)
 749                 *id = id_no;
 750
 751         if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
 752                 oops_hdr = (struct oops_log_info *)buff;
 753                 *buf = buff + sizeof(*oops_hdr);
 754
 755                 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ) {
 756                         big_buff = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 757                         if (!big_buff)
 758                                 return -ENOMEM;
 759
 760                         rc = unzip_oops(buff, big_buff);
 761
 762                         if (rc != 0) {
 763                                 kfree(buff);
 764                                 kfree(big_buff);
 765                                 goto read_partition;
 766                         }
 767
 768                         oops_hdr = (struct oops_log_info *)big_buff;
 769                         *buf = big_buff + sizeof(*oops_hdr);
 770                         kfree(buff);
 771                 }
 772
 773                 time->tv_sec = oops_hdr->timestamp;
 774                 time->tv_nsec = 0;
 775                 return oops_hdr->report_length;
 776         }
 777
 778         *buf = buff;
 779         return part->size;
 780 }
 781
 782 static struct pstore_info nvram_pstore_info = {
 783         .owner = THIS_MODULE,
 784         .name = "nvram",
 785         .open = nvram_pstore_open,
 786         .read = nvram_pstore_read,
 787         .write = nvram_pstore_write,
 788 };
 789
 790 static int nvram_pstore_init(void)
 791 {
 792         int rc = 0;
 793
 794         if (big_oops_buf) {
 795                 nvram_pstore_info.buf = big_oops_buf;
 796                 nvram_pstore_info.bufsize = big_oops_buf_sz;
 797         } else {
 798                 nvram_pstore_info.buf = oops_data;
 799                 nvram_pstore_info.bufsize = oops_data_sz;
 800         }
 801
 802         rc = pstore_register(&nvram_pstore_info);
 803         if (rc != 0)
 804                 pr_err("nvram: pstore_register() failed, defaults to "
 805                                 "kmsg_dump; returned %d\n", rc);
 806
 807         return rc;
 808 }
 809 #else
 810 static int nvram_pstore_init(void)
 811 {
 812         return -1;
 813 }
 814 #endif
 815
 816 static void __init nvram_init_oops_partition(int rtas_partition_exists)
 817 {
 818         int rc;
 819
 820         rc = pseries_nvram_init_os_partition(&oops_log_partition);
 821         if (rc != 0) {
 822                 if (!rtas_partition_exists)
 823                         return;
 824                 pr_notice("nvram: Using %s partition to log both"
 825                         " RTAS errors and oops/panic reports\n",
 826                         rtas_log_partition.name);
 827                 memcpy(&oops_log_partition, &rtas_log_partition,
 828                                                 sizeof(rtas_log_partition));
 829         }
 830         oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
 831         if (!oops_buf) {
 832                 pr_err("nvram: No memory for %s partition\n",
 833                                                 oops_log_partition.name);
 834                 return;
 835         }
 836         oops_data = oops_buf + sizeof(struct oops_log_info);
 837         oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
 838
 839         /*
 840          * Figure compression (preceded by elimination of each line's <n>
 841          * severity prefix) will reduce the oops/panic report to at most
 842          * 45% of its original size.
 843          */
 844         big_oops_buf_sz = (oops_data_sz * 100) / 45;
 845         big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 846         if (big_oops_buf) {
 847                 stream.workspace = kmalloc(zlib_deflate_workspacesize(
 848                                 WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
 849                 if (!stream.workspace) {
 850                         pr_err("nvram: No memory for compression workspace; "
 851                                 "skipping compression of %s partition data\n",
 852                                 oops_log_partition.name);
 853                         kfree(big_oops_buf);
 854                         big_oops_buf = NULL;
 855                 }
 856         } else {
 857                 pr_err("No memory for uncompressed %s data; "
 858                         "skipping compression\n", oops_log_partition.name);
 859                 stream.workspace = NULL;
 860         }
 861
 862         rc = nvram_pstore_init();
 863
 864         if (!rc)
 865                 return;
 866
 867         rc = kmsg_dump_register(&nvram_kmsg_dumper);
 868         if (rc != 0) {
 869                 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
 870                 kfree(oops_buf);
 871                 kfree(big_oops_buf);
 872                 kfree(stream.workspace);
 873         }
 874 }
 875
 876 static int __init pseries_nvram_init_log_partitions(void)
 877 {
 878         int rc;
 879
 880         rc = pseries_nvram_init_os_partition(&rtas_log_partition);
 881         nvram_init_oops_partition(rc == 0);
 882         return 0;
 883 }
 884 machine_arch_initcall(pseries, pseries_nvram_init_log_partitions);
 885
 886 int __init pSeries_nvram_init(void)
 887 {
 888         struct device_node *nvram;
 889         const unsigned int *nbytes_p;
 890         unsigned int proplen;
 891
 892         nvram = of_find_node_by_type(NULL, "nvram");
 893         if (nvram == NULL)
 894                 return -ENODEV;
 895
 896         nbytes_p = of_get_property(nvram, "#bytes", &proplen);
 897         if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
 898                 of_node_put(nvram);
 899                 return -EIO;
 900         }
 901
 902         nvram_size = *nbytes_p;
 903
 904         nvram_fetch = rtas_token("nvram-fetch");
 905         nvram_store = rtas_token("nvram-store");
 906         printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
 907         of_node_put(nvram);
 908
 909         ppc_md.nvram_read       = pSeries_nvram_read;
 910         ppc_md.nvram_write      = pSeries_nvram_write;
 911         ppc_md.nvram_size       = pSeries_nvram_get_size;
 912
 913         return 0;
 914 }
 915
 916
 917 /*
 918  * This is our kmsg_dump callback, called after an oops or panic report
 919  * has been written to the printk buffer.  We want to capture as much
 920  * of the printk buffer as possible.  First, capture as much as we can
 921  * that we think will compress sufficiently to fit in the lnx,oops-log
 922  * partition.  If that's too much, go back and capture uncompressed text.
 923  */
 924 static void oops_to_nvram(struct kmsg_dumper *dumper,
 925                           enum kmsg_dump_reason reason)
 926 {
 927         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 928         static unsigned int oops_count = 0;
 929         static bool panicking = false;
 930         static DEFINE_SPINLOCK(lock);
 931         unsigned long flags;
 932         size_t text_len;
 933         unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 934         int rc = -1;
 935
 936         switch (reason) {
 937         case KMSG_DUMP_RESTART:
 938         case KMSG_DUMP_HALT:
 939         case KMSG_DUMP_POWEROFF:
 940                 /* These are almost always orderly shutdowns. */
 941                 return;
 942         case KMSG_DUMP_OOPS:
 943                 break;
 944         case KMSG_DUMP_PANIC:
 945                 panicking = true;
 946                 break;
 947         case KMSG_DUMP_EMERG:
 948                 if (panicking)
 949                         /* Panic report already captured. */
 950                         return;
 951                 break;
 952         default:
 953                 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
 954                                                 __FUNCTION__, (int) reason);
 955                 return;
 956         }
 957
 958         if (clobbering_unread_rtas_event())
 959                 return;
 960
 961         if (!spin_trylock_irqsave(&lock, flags))
 962                 return;
 963
 964         if (big_oops_buf) {
 965                 kmsg_dump_get_buffer(dumper, false,
 966                                      big_oops_buf, big_oops_buf_sz, &text_len);
 967                 rc = zip_oops(text_len);
 968         }
 969         if (rc != 0) {
 970                 kmsg_dump_rewind(dumper);
 971                 kmsg_dump_get_buffer(dumper, false,
 972                                      oops_data, oops_data_sz, &text_len);
 973                 err_type = ERR_TYPE_KERNEL_PANIC;
 974                 oops_hdr->version = OOPS_HDR_VERSION;
 975                 oops_hdr->report_length = (u16) text_len;
 976                 oops_hdr->timestamp = get_seconds();
 977         }
 978
 979         (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
 980                 (int) (sizeof(*oops_hdr) + oops_hdr->report_length), err_type,
 981                 ++oops_count);
 982
 983         spin_unlock_irqrestore(&lock, flags);
 984 }