arch/powerpc/kernel/nvram_64.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  c 2001 PPC 64 Team, IBM Corp
   4  *
   5  * /dev/nvram driver for PPC64
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/errno.h>
  10 #include <linux/fs.h>
  11 #include <linux/miscdevice.h>
  12 #include <linux/fcntl.h>
  13 #include <linux/nvram.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/kmsg_dump.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/pstore.h>
  20 #include <linux/zlib.h>
  21 #include <linux/uaccess.h>
  22 #include <asm/nvram.h>
  23 #include <asm/rtas.h>
  24 #include <asm/prom.h>
  25 #include <asm/machdep.h>
  26
  27 #undef DEBUG_NVRAM
  28
  29 #define NVRAM_HEADER_LEN        sizeof(struct nvram_header)
  30 #define NVRAM_BLOCK_LEN         NVRAM_HEADER_LEN
  31
  32 /* If change this size, then change the size of NVNAME_LEN */
  33 struct nvram_header {
  34         unsigned char signature;
  35         unsigned char checksum;
  36         unsigned short length;
  37         /* Terminating null required only for names < 12 chars. */
  38         char name[12];
  39 };
  40
  41 struct nvram_partition {
  42         struct list_head partition;
  43         struct nvram_header header;
  44         unsigned int index;
  45 };
  46
  47 static LIST_HEAD(nvram_partitions);
  48
  49 #ifdef CONFIG_PPC_PSERIES
  50 struct nvram_os_partition rtas_log_partition = {
  51         .name = "ibm,rtas-log",
  52         .req_size = 2079,
  53         .min_size = 1055,
  54         .index = -1,
  55         .os_partition = true
  56 };
  57 #endif
  58
  59 struct nvram_os_partition oops_log_partition = {
  60         .name = "lnx,oops-log",
  61         .req_size = 4000,
  62         .min_size = 2000,
  63         .index = -1,
  64         .os_partition = true
  65 };
  66
  67 static const char *nvram_os_partitions[] = {
  68 #ifdef CONFIG_PPC_PSERIES
  69         "ibm,rtas-log",
  70 #endif
  71         "lnx,oops-log",
  72         NULL
  73 };
  74
  75 static void oops_to_nvram(struct kmsg_dumper *dumper,
  76                           enum kmsg_dump_reason reason);
  77
  78 static struct kmsg_dumper nvram_kmsg_dumper = {
  79         .dump = oops_to_nvram
  80 };
  81
  82 /*
  83  * For capturing and compressing an oops or panic report...
  84
  85  * big_oops_buf[] holds the uncompressed text we're capturing.
  86  *
  87  * oops_buf[] holds the compressed text, preceded by a oops header.
  88  * oops header has u16 holding the version of oops header (to differentiate
  89  * between old and new format header) followed by u16 holding the length of
  90  * the compressed* text (*Or uncompressed, if compression fails.) and u64
  91  * holding the timestamp. oops_buf[] gets written to NVRAM.
  92  *
  93  * oops_log_info points to the header. oops_data points to the compressed text.
  94  *
  95  * +- oops_buf
  96  * |                                   +- oops_data
  97  * v                                   v
  98  * +-----------+-----------+-----------+------------------------+
  99  * | version   | length    | timestamp | text                   |
 100  * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes)   |
 101  * +-----------+-----------+-----------+------------------------+
 102  * ^
 103  * +- oops_log_info
 104  *
 105  * We preallocate these buffers during init to avoid kmalloc during oops/panic.
 106  */
 107 static size_t big_oops_buf_sz;
 108 static char *big_oops_buf, *oops_buf;
 109 static char *oops_data;
 110 static size_t oops_data_sz;
 111
 112 /* Compression parameters */
 113 #define COMPR_LEVEL 6
 114 #define WINDOW_BITS 12
 115 #define MEM_LEVEL 4
 116 static struct z_stream_s stream;
 117
 118 #ifdef CONFIG_PSTORE
 119 #ifdef CONFIG_PPC_POWERNV
 120 static struct nvram_os_partition skiboot_partition = {
 121         .name = "ibm,skiboot",
 122         .index = -1,
 123         .os_partition = false
 124 };
 125 #endif
 126
 127 #ifdef CONFIG_PPC_PSERIES
 128 static struct nvram_os_partition of_config_partition = {
 129         .name = "of-config",
 130         .index = -1,
 131         .os_partition = false
 132 };
 133 #endif
 134
 135 static struct nvram_os_partition common_partition = {
 136         .name = "common",
 137         .index = -1,
 138         .os_partition = false
 139 };
 140
 141 static enum pstore_type_id nvram_type_ids[] = {
 142         PSTORE_TYPE_DMESG,
 143         PSTORE_TYPE_PPC_COMMON,
 144         -1,
 145         -1,
 146         -1
 147 };
 148 static int read_type;
 149 #endif
 150
 151 /* nvram_write_os_partition
 152  *
 153  * We need to buffer the error logs into nvram to ensure that we have
 154  * the failure information to decode.  If we have a severe error there
 155  * is no way to guarantee that the OS or the machine is in a state to
 156  * get back to user land and write the error to disk.  For example if
 157  * the SCSI device driver causes a Machine Check by writing to a bad
 158  * IO address, there is no way of guaranteeing that the device driver
 159  * is in any state that is would also be able to write the error data
 160  * captured to disk, thus we buffer it in NVRAM for analysis on the
 161  * next boot.
 162  *
 163  * In NVRAM the partition containing the error log buffer will looks like:
 164  * Header (in bytes):
 165  * +-----------+----------+--------+------------+------------------+
 166  * | signature | checksum | length | name       | data             |
 167  * |0          |1         |2      3|4         15|16        length-1|
 168  * +-----------+----------+--------+------------+------------------+
 169  *
 170  * The 'data' section would look like (in bytes):
 171  * +--------------+------------+-----------------------------------+
 172  * | event_logged | sequence # | error log                         |
 173  * |0            3|4          7|8                  error_log_size-1|
 174  * +--------------+------------+-----------------------------------+
 175  *
 176  * event_logged: 0 if event has not been logged to syslog, 1 if it has
 177  * sequence #: The unique sequence # for each event. (until it wraps)
 178  * error log: The error log from event_scan
 179  */
 180 int nvram_write_os_partition(struct nvram_os_partition *part,
 181                              char *buff, int length,
 182                              unsigned int err_type,
 183                              unsigned int error_log_cnt)
 184 {
 185         int rc;
 186         loff_t tmp_index;
 187         struct err_log_info info;
 188
 189         if (part->index == -1)
 190                 return -ESPIPE;
 191
 192         if (length > part->size)
 193                 length = part->size;
 194
 195         info.error_type = cpu_to_be32(err_type);
 196         info.seq_num = cpu_to_be32(error_log_cnt);
 197
 198         tmp_index = part->index;
 199
 200         rc = ppc_md.nvram_write((char *)&info, sizeof(info), &tmp_index);
 201         if (rc <= 0) {
 202                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 203                 return rc;
 204         }
 205
 206         rc = ppc_md.nvram_write(buff, length, &tmp_index);
 207         if (rc <= 0) {
 208                 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc);
 209                 return rc;
 210         }
 211
 212         return 0;
 213 }
 214
 215 /* nvram_read_partition
 216  *
 217  * Reads nvram partition for at most 'length'
 218  */
 219 int nvram_read_partition(struct nvram_os_partition *part, char *buff,
 220                          int length, unsigned int *err_type,
 221                          unsigned int *error_log_cnt)
 222 {
 223         int rc;
 224         loff_t tmp_index;
 225         struct err_log_info info;
 226
 227         if (part->index == -1)
 228                 return -1;
 229
 230         if (length > part->size)
 231                 length = part->size;
 232
 233         tmp_index = part->index;
 234
 235         if (part->os_partition) {
 236                 rc = ppc_md.nvram_read((char *)&info, sizeof(info), &tmp_index);
 237                 if (rc <= 0) {
 238                         pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 239                         return rc;
 240                 }
 241         }
 242
 243         rc = ppc_md.nvram_read(buff, length, &tmp_index);
 244         if (rc <= 0) {
 245                 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc);
 246                 return rc;
 247         }
 248
 249         if (part->os_partition) {
 250                 *error_log_cnt = be32_to_cpu(info.seq_num);
 251                 *err_type = be32_to_cpu(info.error_type);
 252         }
 253
 254         return 0;
 255 }
 256
 257 /* nvram_init_os_partition
 258  *
 259  * This sets up a partition with an "OS" signature.
 260  *
 261  * The general strategy is the following:
 262  * 1.) If a partition with the indicated name already exists...
 263  *      - If it's large enough, use it.
 264  *      - Otherwise, recycle it and keep going.
 265  * 2.) Search for a free partition that is large enough.
 266  * 3.) If there's not a free partition large enough, recycle any obsolete
 267  * OS partitions and try again.
 268  * 4.) Will first try getting a chunk that will satisfy the requested size.
 269  * 5.) If a chunk of the requested size cannot be allocated, then try finding
 270  * a chunk that will satisfy the minum needed.
 271  *
 272  * Returns 0 on success, else -1.
 273  */
 274 int __init nvram_init_os_partition(struct nvram_os_partition *part)
 275 {
 276         loff_t p;
 277         int size;
 278
 279         /* Look for ours */
 280         p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size);
 281
 282         /* Found one but too small, remove it */
 283         if (p && size < part->min_size) {
 284                 pr_info("nvram: Found too small %s partition,"
 285                                         " removing it...\n", part->name);
 286                 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
 287                 p = 0;
 288         }
 289
 290         /* Create one if we didn't find */
 291         if (!p) {
 292                 p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 293                                         part->req_size, part->min_size);
 294                 if (p == -ENOSPC) {
 295                         pr_info("nvram: No room to create %s partition, "
 296                                 "deleting any obsolete OS partitions...\n",
 297                                 part->name);
 298                         nvram_remove_partition(NULL, NVRAM_SIG_OS,
 299                                         nvram_os_partitions);
 300                         p = nvram_create_partition(part->name, NVRAM_SIG_OS,
 301                                         part->req_size, part->min_size);
 302                 }
 303         }
 304
 305         if (p <= 0) {
 306                 pr_err("nvram: Failed to find or create %s"
 307                        " partition, err %d\n", part->name, (int)p);
 308                 return -1;
 309         }
 310
 311         part->index = p;
 312         part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
 313
 314         return 0;
 315 }
 316
 317 /* Derived from logfs_compress() */
 318 static int nvram_compress(const void *in, void *out, size_t inlen,
 319                                                         size_t outlen)
 320 {
 321         int err, ret;
 322
 323         ret = -EIO;
 324         err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
 325                                                 MEM_LEVEL, Z_DEFAULT_STRATEGY);
 326         if (err != Z_OK)
 327                 goto error;
 328
 329         stream.next_in = in;
 330         stream.avail_in = inlen;
 331         stream.total_in = 0;
 332         stream.next_out = out;
 333         stream.avail_out = outlen;
 334         stream.total_out = 0;
 335
 336         err = zlib_deflate(&stream, Z_FINISH);
 337         if (err != Z_STREAM_END)
 338                 goto error;
 339
 340         err = zlib_deflateEnd(&stream);
 341         if (err != Z_OK)
 342                 goto error;
 343
 344         if (stream.total_out >= stream.total_in)
 345                 goto error;
 346
 347         ret = stream.total_out;
 348 error:
 349         return ret;
 350 }
 351
 352 /* Compress the text from big_oops_buf into oops_buf. */
 353 static int zip_oops(size_t text_len)
 354 {
 355         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 356         int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len,
 357                                                                 oops_data_sz);
 358         if (zipped_len < 0) {
 359                 pr_err("nvram: compression failed; returned %d\n", zipped_len);
 360                 pr_err("nvram: logging uncompressed oops/panic report\n");
 361                 return -1;
 362         }
 363         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 364         oops_hdr->report_length = cpu_to_be16(zipped_len);
 365         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 366         return 0;
 367 }
 368
 369 #ifdef CONFIG_PSTORE
 370 static int nvram_pstore_open(struct pstore_info *psi)
 371 {
 372         /* Reset the iterator to start reading partitions again */
 373         read_type = -1;
 374         return 0;
 375 }
 376
 377 /**
 378  * nvram_pstore_write - pstore write callback for nvram
 379  * @record:             pstore record to write, with @id to be set
 380  *
 381  * Called by pstore_dump() when an oops or panic report is logged in the
 382  * printk buffer.
 383  * Returns 0 on successful write.
 384  */
 385 static int nvram_pstore_write(struct pstore_record *record)
 386 {
 387         int rc;
 388         unsigned int err_type = ERR_TYPE_KERNEL_PANIC;
 389         struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf;
 390
 391         /* part 1 has the recent messages from printk buffer */
 392         if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG))
 393                 return -1;
 394
 395         if (clobbering_unread_rtas_event())
 396                 return -1;
 397
 398         oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 399         oops_hdr->report_length = cpu_to_be16(record->size);
 400         oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 401
 402         if (record->compressed)
 403                 err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 404
 405         rc = nvram_write_os_partition(&oops_log_partition, oops_buf,
 406                 (int) (sizeof(*oops_hdr) + record->size), err_type,
 407                 record->count);
 408
 409         if (rc != 0)
 410                 return rc;
 411
 412         record->id = record->part;
 413         return 0;
 414 }
 415
 416 /*
 417  * Reads the oops/panic report, rtas, of-config and common partition.
 418  * Returns the length of the data we read from each partition.
 419  * Returns 0 if we've been called before.
 420  */
 421 static ssize_t nvram_pstore_read(struct pstore_record *record)
 422 {
 423         struct oops_log_info *oops_hdr;
 424         unsigned int err_type, id_no, size = 0;
 425         struct nvram_os_partition *part = NULL;
 426         char *buff = NULL;
 427         int sig = 0;
 428         loff_t p;
 429
 430         read_type++;
 431
 432         switch (nvram_type_ids[read_type]) {
 433         case PSTORE_TYPE_DMESG:
 434                 part = &oops_log_partition;
 435                 record->type = PSTORE_TYPE_DMESG;
 436                 break;
 437         case PSTORE_TYPE_PPC_COMMON:
 438                 sig = NVRAM_SIG_SYS;
 439                 part = &common_partition;
 440                 record->type = PSTORE_TYPE_PPC_COMMON;
 441                 record->id = PSTORE_TYPE_PPC_COMMON;
 442                 record->time.tv_sec = 0;
 443                 record->time.tv_nsec = 0;
 444                 break;
 445 #ifdef CONFIG_PPC_PSERIES
 446         case PSTORE_TYPE_PPC_RTAS:
 447                 part = &rtas_log_partition;
 448                 record->type = PSTORE_TYPE_PPC_RTAS;
 449                 record->time.tv_sec = last_rtas_event;
 450                 record->time.tv_nsec = 0;
 451                 break;
 452         case PSTORE_TYPE_PPC_OF:
 453                 sig = NVRAM_SIG_OF;
 454                 part = &of_config_partition;
 455                 record->type = PSTORE_TYPE_PPC_OF;
 456                 record->id = PSTORE_TYPE_PPC_OF;
 457                 record->time.tv_sec = 0;
 458                 record->time.tv_nsec = 0;
 459                 break;
 460 #endif
 461 #ifdef CONFIG_PPC_POWERNV
 462         case PSTORE_TYPE_PPC_OPAL:
 463                 sig = NVRAM_SIG_FW;
 464                 part = &skiboot_partition;
 465                 record->type = PSTORE_TYPE_PPC_OPAL;
 466                 record->id = PSTORE_TYPE_PPC_OPAL;
 467                 record->time.tv_sec = 0;
 468                 record->time.tv_nsec = 0;
 469                 break;
 470 #endif
 471         default:
 472                 return 0;
 473         }
 474
 475         if (!part->os_partition) {
 476                 p = nvram_find_partition(part->name, sig, &size);
 477                 if (p <= 0) {
 478                         pr_err("nvram: Failed to find partition %s, "
 479                                 "err %d\n", part->name, (int)p);
 480                         return 0;
 481                 }
 482                 part->index = p;
 483                 part->size = size;
 484         }
 485
 486         buff = kmalloc(part->size, GFP_KERNEL);
 487
 488         if (!buff)
 489                 return -ENOMEM;
 490
 491         if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) {
 492                 kfree(buff);
 493                 return 0;
 494         }
 495
 496         record->count = 0;
 497
 498         if (part->os_partition)
 499                 record->id = id_no;
 500
 501         if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
 502                 size_t length, hdr_size;
 503
 504                 oops_hdr = (struct oops_log_info *)buff;
 505                 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) {
 506                         /* Old format oops header had 2-byte record size */
 507                         hdr_size = sizeof(u16);
 508                         length = be16_to_cpu(oops_hdr->version);
 509                         record->time.tv_sec = 0;
 510                         record->time.tv_nsec = 0;
 511                 } else {
 512                         hdr_size = sizeof(*oops_hdr);
 513                         length = be16_to_cpu(oops_hdr->report_length);
 514                         record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp);
 515                         record->time.tv_nsec = 0;
 516                 }
 517                 record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL);
 518                 kfree(buff);
 519                 if (record->buf == NULL)
 520                         return -ENOMEM;
 521
 522                 record->ecc_notice_size = 0;
 523                 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ)
 524                         record->compressed = true;
 525                 else
 526                         record->compressed = false;
 527                 return length;
 528         }
 529
 530         record->buf = buff;
 531         return part->size;
 532 }
 533
 534 static struct pstore_info nvram_pstore_info = {
 535         .owner = THIS_MODULE,
 536         .name = "nvram",
 537         .flags = PSTORE_FLAGS_DMESG,
 538         .open = nvram_pstore_open,
 539         .read = nvram_pstore_read,
 540         .write = nvram_pstore_write,
 541 };
 542
 543 static int nvram_pstore_init(void)
 544 {
 545         int rc = 0;
 546
 547         if (machine_is(pseries)) {
 548                 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS;
 549                 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF;
 550         } else
 551                 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL;
 552
 553         nvram_pstore_info.buf = oops_data;
 554         nvram_pstore_info.bufsize = oops_data_sz;
 555
 556         rc = pstore_register(&nvram_pstore_info);
 557         if (rc && (rc != -EPERM))
 558                 /* Print error only when pstore.backend == nvram */
 559                 pr_err("nvram: pstore_register() failed, returned %d. "
 560                                 "Defaults to kmsg_dump\n", rc);
 561
 562         return rc;
 563 }
 564 #else
 565 static int nvram_pstore_init(void)
 566 {
 567         return -1;
 568 }
 569 #endif
 570
 571 void __init nvram_init_oops_partition(int rtas_partition_exists)
 572 {
 573         int rc;
 574
 575         rc = nvram_init_os_partition(&oops_log_partition);
 576         if (rc != 0) {
 577 #ifdef CONFIG_PPC_PSERIES
 578                 if (!rtas_partition_exists) {
 579                         pr_err("nvram: Failed to initialize oops partition!");
 580                         return;
 581                 }
 582                 pr_notice("nvram: Using %s partition to log both"
 583                         " RTAS errors and oops/panic reports\n",
 584                         rtas_log_partition.name);
 585                 memcpy(&oops_log_partition, &rtas_log_partition,
 586                                                 sizeof(rtas_log_partition));
 587 #else
 588                 pr_err("nvram: Failed to initialize oops partition!");
 589                 return;
 590 #endif
 591         }
 592         oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL);
 593         if (!oops_buf) {
 594                 pr_err("nvram: No memory for %s partition\n",
 595                                                 oops_log_partition.name);
 596                 return;
 597         }
 598         oops_data = oops_buf + sizeof(struct oops_log_info);
 599         oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info);
 600
 601         rc = nvram_pstore_init();
 602
 603         if (!rc)
 604                 return;
 605
 606         /*
 607          * Figure compression (preceded by elimination of each line's <n>
 608          * severity prefix) will reduce the oops/panic report to at most
 609          * 45% of its original size.
 610          */
 611         big_oops_buf_sz = (oops_data_sz * 100) / 45;
 612         big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
 613         if (big_oops_buf) {
 614                 stream.workspace =  kmalloc(zlib_deflate_workspacesize(
 615                                         WINDOW_BITS, MEM_LEVEL), GFP_KERNEL);
 616                 if (!stream.workspace) {
 617                         pr_err("nvram: No memory for compression workspace; "
 618                                 "skipping compression of %s partition data\n",
 619                                 oops_log_partition.name);
 620                         kfree(big_oops_buf);
 621                         big_oops_buf = NULL;
 622                 }
 623         } else {
 624                 pr_err("No memory for uncompressed %s data; "
 625                         "skipping compression\n", oops_log_partition.name);
 626                 stream.workspace = NULL;
 627         }
 628
 629         rc = kmsg_dump_register(&nvram_kmsg_dumper);
 630         if (rc != 0) {
 631                 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc);
 632                 kfree(oops_buf);
 633                 kfree(big_oops_buf);
 634                 kfree(stream.workspace);
 635         }
 636 }
 637
 638 /*
 639  * This is our kmsg_dump callback, called after an oops or panic report
 640  * has been written to the printk buffer.  We want to capture as much
 641  * of the printk buffer as possible.  First, capture as much as we can
 642  * that we think will compress sufficiently to fit in the lnx,oops-log
 643  * partition.  If that's too much, go back and capture uncompressed text.
 644  */
 645 static void oops_to_nvram(struct kmsg_dumper *dumper,
 646                           enum kmsg_dump_reason reason)
 647 {
 648         struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf;
 649         static unsigned int oops_count = 0;
 650         static struct kmsg_dump_iter iter;
 651         static bool panicking = false;
 652         static DEFINE_SPINLOCK(lock);
 653         unsigned long flags;
 654         size_t text_len;
 655         unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 656         int rc = -1;
 657
 658         switch (reason) {
 659         case KMSG_DUMP_SHUTDOWN:
 660                 /* These are almost always orderly shutdowns. */
 661                 return;
 662         case KMSG_DUMP_OOPS:
 663                 break;
 664         case KMSG_DUMP_PANIC:
 665                 panicking = true;
 666                 break;
 667         case KMSG_DUMP_EMERG:
 668                 if (panicking)
 669                         /* Panic report already captured. */
 670                         return;
 671                 break;
 672         default:
 673                 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
 674                        __func__, (int) reason);
 675                 return;
 676         }
 677
 678         if (clobbering_unread_rtas_event())
 679                 return;
 680
 681         if (!spin_trylock_irqsave(&lock, flags))
 682                 return;
 683
 684         if (big_oops_buf) {
 685                 kmsg_dump_rewind(&iter);
 686                 kmsg_dump_get_buffer(&iter, false,
 687                                      big_oops_buf, big_oops_buf_sz, &text_len);
 688                 rc = zip_oops(text_len);
 689         }
 690         if (rc != 0) {
 691                 kmsg_dump_rewind(&iter);
 692                 kmsg_dump_get_buffer(&iter, false,
 693                                      oops_data, oops_data_sz, &text_len);
 694                 err_type = ERR_TYPE_KERNEL_PANIC;
 695                 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION);
 696                 oops_hdr->report_length = cpu_to_be16(text_len);
 697                 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds());
 698         }
 699
 700         (void) nvram_write_os_partition(&oops_log_partition, oops_buf,
 701                 (int) (sizeof(*oops_hdr) + text_len), err_type,
 702                 ++oops_count);
 703
 704         spin_unlock_irqrestore(&lock, flags);
 705 }
 706
 707 #ifdef DEBUG_NVRAM
 708 static void __init nvram_print_partitions(char * label)
 709 {
 710         struct nvram_partition * tmp_part;
 711
 712         printk(KERN_WARNING "--------%s---------\n", label);
 713         printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n");
 714         list_for_each_entry(tmp_part, &nvram_partitions, partition) {
 715                 printk(KERN_WARNING "%4d    \t%02x\t%02x\t%d\t%12.12s\n",
 716                        tmp_part->index, tmp_part->header.signature,
 717                        tmp_part->header.checksum, tmp_part->header.length,
 718                        tmp_part->header.name);
 719         }
 720 }
 721 #endif
 722
 723
 724 static int __init nvram_write_header(struct nvram_partition * part)
 725 {
 726         loff_t tmp_index;
 727         int rc;
 728         struct nvram_header phead;
 729
 730         memcpy(&phead, &part->header, NVRAM_HEADER_LEN);
 731         phead.length = cpu_to_be16(phead.length);
 732
 733         tmp_index = part->index;
 734         rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index);
 735
 736         return rc;
 737 }
 738
 739
 740 static unsigned char __init nvram_checksum(struct nvram_header *p)
 741 {
 742         unsigned int c_sum, c_sum2;
 743         unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */
 744         c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5];
 745
 746         /* The sum may have spilled into the 3rd byte.  Fold it back. */
 747         c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff;
 748         /* The sum cannot exceed 2 bytes.  Fold it into a checksum */
 749         c_sum2 = (c_sum >> 8) + (c_sum << 8);
 750         c_sum = ((c_sum + c_sum2) >> 8) & 0xff;
 751         return c_sum;
 752 }
 753
 754 /*
 755  * Per the criteria passed via nvram_remove_partition(), should this
 756  * partition be removed?  1=remove, 0=keep
 757  */
 758 static int nvram_can_remove_partition(struct nvram_partition *part,
 759                 const char *name, int sig, const char *exceptions[])
 760 {
 761         if (part->header.signature != sig)
 762                 return 0;
 763         if (name) {
 764                 if (strncmp(name, part->header.name, 12))
 765                         return 0;
 766         } else if (exceptions) {
 767                 const char **except;
 768                 for (except = exceptions; *except; except++) {
 769                         if (!strncmp(*except, part->header.name, 12))
 770                                 return 0;
 771                 }
 772         }
 773         return 1;
 774 }
 775
 776 /**
 777  * nvram_remove_partition - Remove one or more partitions in nvram
 778  * @name: name of the partition to remove, or NULL for a
 779  *        signature only match
 780  * @sig: signature of the partition(s) to remove
 781  * @exceptions: When removing all partitions with a matching signature,
 782  *        leave these alone.
 783  */
 784
 785 int __init nvram_remove_partition(const char *name, int sig,
 786                                                 const char *exceptions[])
 787 {
 788         struct nvram_partition *part, *prev, *tmp;
 789         int rc;
 790
 791         list_for_each_entry(part, &nvram_partitions, partition) {
 792                 if (!nvram_can_remove_partition(part, name, sig, exceptions))
 793                         continue;
 794
 795                 /* Make partition a free partition */
 796                 part->header.signature = NVRAM_SIG_FREE;
 797                 memset(part->header.name, 'w', 12);
 798                 part->header.checksum = nvram_checksum(&part->header);
 799                 rc = nvram_write_header(part);
 800                 if (rc <= 0) {
 801                         printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 802                         return rc;
 803                 }
 804         }
 805
 806         /* Merge contiguous ones */
 807         prev = NULL;
 808         list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) {
 809                 if (part->header.signature != NVRAM_SIG_FREE) {
 810                         prev = NULL;
 811                         continue;
 812                 }
 813                 if (prev) {
 814                         prev->header.length += part->header.length;
 815                         prev->header.checksum = nvram_checksum(&prev->header);
 816                         rc = nvram_write_header(prev);
 817                         if (rc <= 0) {
 818                                 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 819                                 return rc;
 820                         }
 821                         list_del(&part->partition);
 822                         kfree(part);
 823                 } else
 824                         prev = part;
 825         }
 826
 827         return 0;
 828 }
 829
 830 /**
 831  * nvram_create_partition - Create a partition in nvram
 832  * @name: name of the partition to create
 833  * @sig: signature of the partition to create
 834  * @req_size: size of data to allocate in bytes
 835  * @min_size: minimum acceptable size (0 means req_size)
 836  *
 837  * Returns a negative error code or a positive nvram index
 838  * of the beginning of the data area of the newly created
 839  * partition. If you provided a min_size smaller than req_size
 840  * you need to query for the actual size yourself after the
 841  * call using nvram_partition_get_size().
 842  */
 843 loff_t __init nvram_create_partition(const char *name, int sig,
 844                                      int req_size, int min_size)
 845 {
 846         struct nvram_partition *part;
 847         struct nvram_partition *new_part;
 848         struct nvram_partition *free_part = NULL;
 849         static char nv_init_vals[16];
 850         loff_t tmp_index;
 851         long size = 0;
 852         int rc;
 853
 854         BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16);
 855
 856         /* Convert sizes from bytes to blocks */
 857         req_size = ALIGN(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
 858         min_size = ALIGN(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
 859
 860         /* If no minimum size specified, make it the same as the
 861          * requested size
 862          */
 863         if (min_size == 0)
 864                 min_size = req_size;
 865         if (min_size > req_size)
 866                 return -EINVAL;
 867
 868         /* Now add one block to each for the header */
 869         req_size += 1;
 870         min_size += 1;
 871
 872         /* Find a free partition that will give us the maximum needed size
 873            If can't find one that will give us the minimum size needed */
 874         list_for_each_entry(part, &nvram_partitions, partition) {
 875                 if (part->header.signature != NVRAM_SIG_FREE)
 876                         continue;
 877
 878                 if (part->header.length >= req_size) {
 879                         size = req_size;
 880                         free_part = part;
 881                         break;
 882                 }
 883                 if (part->header.length > size &&
 884                     part->header.length >= min_size) {
 885                         size = part->header.length;
 886                         free_part = part;
 887                 }
 888         }
 889         if (!size)
 890                 return -ENOSPC;
 891
 892         /* Create our OS partition */
 893         new_part = kzalloc(sizeof(*new_part), GFP_KERNEL);
 894         if (!new_part) {
 895                 pr_err("%s: kmalloc failed\n", __func__);
 896                 return -ENOMEM;
 897         }
 898
 899         new_part->index = free_part->index;
 900         new_part->header.signature = sig;
 901         new_part->header.length = size;
 902         memcpy(new_part->header.name, name, strnlen(name, sizeof(new_part->header.name)));
 903         new_part->header.checksum = nvram_checksum(&new_part->header);
 904
 905         rc = nvram_write_header(new_part);
 906         if (rc <= 0) {
 907                 pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc);
 908                 kfree(new_part);
 909                 return rc;
 910         }
 911         list_add_tail(&new_part->partition, &free_part->partition);
 912
 913         /* Adjust or remove the partition we stole the space from */
 914         if (free_part->header.length > size) {
 915                 free_part->index += size * NVRAM_BLOCK_LEN;
 916                 free_part->header.length -= size;
 917                 free_part->header.checksum = nvram_checksum(&free_part->header);
 918                 rc = nvram_write_header(free_part);
 919                 if (rc <= 0) {
 920                         pr_err("%s: nvram_write_header failed (%d)\n",
 921                                __func__, rc);
 922                         return rc;
 923                 }
 924         } else {
 925                 list_del(&free_part->partition);
 926                 kfree(free_part);
 927         }
 928
 929         /* Clear the new partition */
 930         for (tmp_index = new_part->index + NVRAM_HEADER_LEN;
 931              tmp_index <  ((size - 1) * NVRAM_BLOCK_LEN);
 932              tmp_index += NVRAM_BLOCK_LEN) {
 933                 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index);
 934                 if (rc <= 0) {
 935                         pr_err("%s: nvram_write failed (%d)\n",
 936                                __func__, rc);
 937                         return rc;
 938                 }
 939         }
 940
 941         return new_part->index + NVRAM_HEADER_LEN;
 942 }
 943
 944 /**
 945  * nvram_get_partition_size - Get the data size of an nvram partition
 946  * @data_index: This is the offset of the start of the data of
 947  *              the partition. The same value that is returned by
 948  *              nvram_create_partition().
 949  */
 950 int nvram_get_partition_size(loff_t data_index)
 951 {
 952         struct nvram_partition *part;
 953
 954         list_for_each_entry(part, &nvram_partitions, partition) {
 955                 if (part->index + NVRAM_HEADER_LEN == data_index)
 956                         return (part->header.length - 1) * NVRAM_BLOCK_LEN;
 957         }
 958         return -1;
 959 }
 960
 961
 962 /**
 963  * nvram_find_partition - Find an nvram partition by signature and name
 964  * @name: Name of the partition or NULL for any name
 965  * @sig: Signature to test against
 966  * @out_size: if non-NULL, returns the size of the data part of the partition
 967  */
 968 loff_t nvram_find_partition(const char *name, int sig, int *out_size)
 969 {
 970         struct nvram_partition *p;
 971
 972         list_for_each_entry(p, &nvram_partitions, partition) {
 973                 if (p->header.signature == sig &&
 974                     (!name || !strncmp(p->header.name, name, 12))) {
 975                         if (out_size)
 976                                 *out_size = (p->header.length - 1) *
 977                                         NVRAM_BLOCK_LEN;
 978                         return p->index + NVRAM_HEADER_LEN;
 979                 }
 980         }
 981         return 0;
 982 }
 983
 984 int __init nvram_scan_partitions(void)
 985 {
 986         loff_t cur_index = 0;
 987         struct nvram_header phead;
 988         struct nvram_partition * tmp_part;
 989         unsigned char c_sum;
 990         char * header;
 991         int total_size;
 992         int err;
 993
 994         if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0)
 995                 return -ENODEV;
 996         total_size = ppc_md.nvram_size();
 997
 998         header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL);
 999         if (!header) {
1000                 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n");
1001                 return -ENOMEM;
1002         }
1003
1004         while (cur_index < total_size) {
1005
1006                 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index);
1007                 if (err != NVRAM_HEADER_LEN) {
1008                         printk(KERN_ERR "nvram_scan_partitions: Error parsing "
1009                                "nvram partitions\n");
1010                         goto out;
1011                 }
1012
1013                 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */
1014
1015                 memcpy(&phead, header, NVRAM_HEADER_LEN);
1016
1017                 phead.length = be16_to_cpu(phead.length);
1018
1019                 err = 0;
1020                 c_sum = nvram_checksum(&phead);
1021                 if (c_sum != phead.checksum) {
1022                         printk(KERN_WARNING "WARNING: nvram partition checksum"
1023                                " was %02x, should be %02x!\n",
1024                                phead.checksum, c_sum);
1025                         printk(KERN_WARNING "Terminating nvram partition scan\n");
1026                         goto out;
1027                 }
1028                 if (!phead.length) {
1029                         printk(KERN_WARNING "WARNING: nvram corruption "
1030                                "detected: 0-length partition\n");
1031                         goto out;
1032                 }
1033                 tmp_part = kmalloc(sizeof(*tmp_part), GFP_KERNEL);
1034                 err = -ENOMEM;
1035                 if (!tmp_part) {
1036                         printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n");
1037                         goto out;
1038                 }
1039
1040                 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN);
1041                 tmp_part->index = cur_index;
1042                 list_add_tail(&tmp_part->partition, &nvram_partitions);
1043
1044                 cur_index += phead.length * NVRAM_BLOCK_LEN;
1045         }
1046         err = 0;
1047
1048 #ifdef DEBUG_NVRAM
1049         nvram_print_partitions("NVRAM Partitions");
1050 #endif
1051
1052  out:
1053         kfree(header);
1054         return err;
1055 }