linux/arch/powerpc/kernel/nvram_64.c
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   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 */
  33struct 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
  41struct nvram_partition {
  42        struct list_head partition;
  43        struct nvram_header header;
  44        unsigned int index;
  45};
  46
  47static LIST_HEAD(nvram_partitions);
  48
  49#ifdef CONFIG_PPC_PSERIES
  50struct 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
  59struct 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
  67static const char *nvram_os_partitions[] = {
  68#ifdef CONFIG_PPC_PSERIES
  69        "ibm,rtas-log",
  70#endif
  71        "lnx,oops-log",
  72        NULL
  73};
  74
  75static void oops_to_nvram(struct kmsg_dumper *dumper,
  76                          enum kmsg_dump_reason reason);
  77
  78static 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 */
 107static size_t big_oops_buf_sz;
 108static char *big_oops_buf, *oops_buf;
 109static char *oops_data;
 110static size_t oops_data_sz;
 111
 112/* Compression parameters */
 113#define COMPR_LEVEL 6
 114#define WINDOW_BITS 12
 115#define MEM_LEVEL 4
 116static struct z_stream_s stream;
 117
 118#ifdef CONFIG_PSTORE
 119#ifdef CONFIG_PPC_POWERNV
 120static 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
 128static struct nvram_os_partition of_config_partition = {
 129        .name = "of-config",
 130        .index = -1,
 131        .os_partition = false
 132};
 133#endif
 134
 135static struct nvram_os_partition common_partition = {
 136        .name = "common",
 137        .index = -1,
 138        .os_partition = false
 139};
 140
 141static enum pstore_type_id nvram_type_ids[] = {
 142        PSTORE_TYPE_DMESG,
 143        PSTORE_TYPE_PPC_COMMON,
 144        -1,
 145        -1,
 146        -1
 147};
 148static 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 */
 180int 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 */
 219int 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 */
 274int __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() */
 318static 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;
 348error:
 349        return ret;
 350}
 351
 352/* Compress the text from big_oops_buf into oops_buf. */
 353static 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
 370static 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 */
 385static 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 */
 421static 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
 534static 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
 543static 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
 565static int nvram_pstore_init(void)
 566{
 567        return -1;
 568}
 569#endif
 570
 571void __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 */
 645static 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 bool panicking = false;
 651        static DEFINE_SPINLOCK(lock);
 652        unsigned long flags;
 653        size_t text_len;
 654        unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ;
 655        int rc = -1;
 656
 657        switch (reason) {
 658        case KMSG_DUMP_RESTART:
 659        case KMSG_DUMP_HALT:
 660        case KMSG_DUMP_POWEROFF:
 661                /* These are almost always orderly shutdowns. */
 662                return;
 663        case KMSG_DUMP_OOPS:
 664                break;
 665        case KMSG_DUMP_PANIC:
 666                panicking = true;
 667                break;
 668        case KMSG_DUMP_EMERG:
 669                if (panicking)
 670                        /* Panic report already captured. */
 671                        return;
 672                break;
 673        default:
 674                pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n",
 675                       __func__, (int) reason);
 676                return;
 677        }
 678
 679        if (clobbering_unread_rtas_event())
 680                return;
 681
 682        if (!spin_trylock_irqsave(&lock, flags))
 683                return;
 684
 685        if (big_oops_buf) {
 686                kmsg_dump_get_buffer(dumper, 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(dumper);
 692                kmsg_dump_get_buffer(dumper, 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
 708static 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
 724static 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
 740static 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 */
 758static 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
 785int __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 */
 843loff_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_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN;
 858        min_size = _ALIGN_UP(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 */
 950int 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 */
 968loff_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
 984int __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}
1056