1 /* 2 * c 2001 PPC 64 Team, IBM Corp 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * /dev/nvram driver for PPC64 10 * 11 * This perhaps should live in drivers/char 12 * 13 * TODO: Split the /dev/nvram part (that one can use 14 * drivers/char/generic_nvram.c) from the arch & partition 15 * parsing code. 16 */ 17 18 #include <linux/types.h> 19 #include <linux/errno.h> 20 #include <linux/fs.h> 21 #include <linux/miscdevice.h> 22 #include <linux/fcntl.h> 23 #include <linux/nvram.h> 24 #include <linux/init.h> 25 #include <linux/slab.h> 26 #include <linux/spinlock.h> 27 #include <linux/kmsg_dump.h> 28 #include <linux/pagemap.h> 29 #include <linux/pstore.h> 30 #include <linux/zlib.h> 31 #include <linux/uaccess.h> 32 #include <asm/nvram.h> 33 #include <asm/rtas.h> 34 #include <asm/prom.h> 35 #include <asm/machdep.h> 36 37 #undef DEBUG_NVRAM 38 39 #define NVRAM_HEADER_LEN sizeof(struct nvram_header) 40 #define NVRAM_BLOCK_LEN NVRAM_HEADER_LEN 41 42 /* If change this size, then change the size of NVNAME_LEN */ 43 struct nvram_header { 44 unsigned char signature; 45 unsigned char checksum; 46 unsigned short length; 47 /* Terminating null required only for names < 12 chars. */ 48 char name[12]; 49 }; 50 51 struct nvram_partition { 52 struct list_head partition; 53 struct nvram_header header; 54 unsigned int index; 55 }; 56 57 static LIST_HEAD(nvram_partitions); 58 59 #ifdef CONFIG_PPC_PSERIES 60 struct nvram_os_partition rtas_log_partition = { 61 .name = "ibm,rtas-log", 62 .req_size = 2079, 63 .min_size = 1055, 64 .index = -1, 65 .os_partition = true 66 }; 67 #endif 68 69 struct nvram_os_partition oops_log_partition = { 70 .name = "lnx,oops-log", 71 .req_size = 4000, 72 .min_size = 2000, 73 .index = -1, 74 .os_partition = true 75 }; 76 77 static const char *nvram_os_partitions[] = { 78 #ifdef CONFIG_PPC_PSERIES 79 "ibm,rtas-log", 80 #endif 81 "lnx,oops-log", 82 NULL 83 }; 84 85 static void oops_to_nvram(struct kmsg_dumper *dumper, 86 enum kmsg_dump_reason reason); 87 88 static struct kmsg_dumper nvram_kmsg_dumper = { 89 .dump = oops_to_nvram 90 }; 91 92 /* 93 * For capturing and compressing an oops or panic report... 94 95 * big_oops_buf[] holds the uncompressed text we're capturing. 96 * 97 * oops_buf[] holds the compressed text, preceded by a oops header. 98 * oops header has u16 holding the version of oops header (to differentiate 99 * between old and new format header) followed by u16 holding the length of 100 * the compressed* text (*Or uncompressed, if compression fails.) and u64 101 * holding the timestamp. oops_buf[] gets written to NVRAM. 102 * 103 * oops_log_info points to the header. oops_data points to the compressed text. 104 * 105 * +- oops_buf 106 * | +- oops_data 107 * v v 108 * +-----------+-----------+-----------+------------------------+ 109 * | version | length | timestamp | text | 110 * | (2 bytes) | (2 bytes) | (8 bytes) | (oops_data_sz bytes) | 111 * +-----------+-----------+-----------+------------------------+ 112 * ^ 113 * +- oops_log_info 114 * 115 * We preallocate these buffers during init to avoid kmalloc during oops/panic. 116 */ 117 static size_t big_oops_buf_sz; 118 static char *big_oops_buf, *oops_buf; 119 static char *oops_data; 120 static size_t oops_data_sz; 121 122 /* Compression parameters */ 123 #define COMPR_LEVEL 6 124 #define WINDOW_BITS 12 125 #define MEM_LEVEL 4 126 static struct z_stream_s stream; 127 128 #ifdef CONFIG_PSTORE 129 #ifdef CONFIG_PPC_POWERNV 130 static struct nvram_os_partition skiboot_partition = { 131 .name = "ibm,skiboot", 132 .index = -1, 133 .os_partition = false 134 }; 135 #endif 136 137 #ifdef CONFIG_PPC_PSERIES 138 static struct nvram_os_partition of_config_partition = { 139 .name = "of-config", 140 .index = -1, 141 .os_partition = false 142 }; 143 #endif 144 145 static struct nvram_os_partition common_partition = { 146 .name = "common", 147 .index = -1, 148 .os_partition = false 149 }; 150 151 static enum pstore_type_id nvram_type_ids[] = { 152 PSTORE_TYPE_DMESG, 153 PSTORE_TYPE_PPC_COMMON, 154 -1, 155 -1, 156 -1 157 }; 158 static int read_type; 159 #endif 160 161 /* nvram_write_os_partition 162 * 163 * We need to buffer the error logs into nvram to ensure that we have 164 * the failure information to decode. If we have a severe error there 165 * is no way to guarantee that the OS or the machine is in a state to 166 * get back to user land and write the error to disk. For example if 167 * the SCSI device driver causes a Machine Check by writing to a bad 168 * IO address, there is no way of guaranteeing that the device driver 169 * is in any state that is would also be able to write the error data 170 * captured to disk, thus we buffer it in NVRAM for analysis on the 171 * next boot. 172 * 173 * In NVRAM the partition containing the error log buffer will looks like: 174 * Header (in bytes): 175 * +-----------+----------+--------+------------+------------------+ 176 * | signature | checksum | length | name | data | 177 * |0 |1 |2 3|4 15|16 length-1| 178 * +-----------+----------+--------+------------+------------------+ 179 * 180 * The 'data' section would look like (in bytes): 181 * +--------------+------------+-----------------------------------+ 182 * | event_logged | sequence # | error log | 183 * |0 3|4 7|8 error_log_size-1| 184 * +--------------+------------+-----------------------------------+ 185 * 186 * event_logged: 0 if event has not been logged to syslog, 1 if it has 187 * sequence #: The unique sequence # for each event. (until it wraps) 188 * error log: The error log from event_scan 189 */ 190 int nvram_write_os_partition(struct nvram_os_partition *part, 191 char *buff, int length, 192 unsigned int err_type, 193 unsigned int error_log_cnt) 194 { 195 int rc; 196 loff_t tmp_index; 197 struct err_log_info info; 198 199 if (part->index == -1) 200 return -ESPIPE; 201 202 if (length > part->size) 203 length = part->size; 204 205 info.error_type = cpu_to_be32(err_type); 206 info.seq_num = cpu_to_be32(error_log_cnt); 207 208 tmp_index = part->index; 209 210 rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), 211 &tmp_index); 212 if (rc <= 0) { 213 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc); 214 return rc; 215 } 216 217 rc = ppc_md.nvram_write(buff, length, &tmp_index); 218 if (rc <= 0) { 219 pr_err("%s: Failed nvram_write (%d)\n", __func__, rc); 220 return rc; 221 } 222 223 return 0; 224 } 225 226 /* nvram_read_partition 227 * 228 * Reads nvram partition for at most 'length' 229 */ 230 int nvram_read_partition(struct nvram_os_partition *part, char *buff, 231 int length, unsigned int *err_type, 232 unsigned int *error_log_cnt) 233 { 234 int rc; 235 loff_t tmp_index; 236 struct err_log_info info; 237 238 if (part->index == -1) 239 return -1; 240 241 if (length > part->size) 242 length = part->size; 243 244 tmp_index = part->index; 245 246 if (part->os_partition) { 247 rc = ppc_md.nvram_read((char *)&info, 248 sizeof(struct err_log_info), 249 &tmp_index); 250 if (rc <= 0) { 251 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc); 252 return rc; 253 } 254 } 255 256 rc = ppc_md.nvram_read(buff, length, &tmp_index); 257 if (rc <= 0) { 258 pr_err("%s: Failed nvram_read (%d)\n", __func__, rc); 259 return rc; 260 } 261 262 if (part->os_partition) { 263 *error_log_cnt = be32_to_cpu(info.seq_num); 264 *err_type = be32_to_cpu(info.error_type); 265 } 266 267 return 0; 268 } 269 270 /* nvram_init_os_partition 271 * 272 * This sets up a partition with an "OS" signature. 273 * 274 * The general strategy is the following: 275 * 1.) If a partition with the indicated name already exists... 276 * - If it's large enough, use it. 277 * - Otherwise, recycle it and keep going. 278 * 2.) Search for a free partition that is large enough. 279 * 3.) If there's not a free partition large enough, recycle any obsolete 280 * OS partitions and try again. 281 * 4.) Will first try getting a chunk that will satisfy the requested size. 282 * 5.) If a chunk of the requested size cannot be allocated, then try finding 283 * a chunk that will satisfy the minum needed. 284 * 285 * Returns 0 on success, else -1. 286 */ 287 int __init nvram_init_os_partition(struct nvram_os_partition *part) 288 { 289 loff_t p; 290 int size; 291 292 /* Look for ours */ 293 p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size); 294 295 /* Found one but too small, remove it */ 296 if (p && size < part->min_size) { 297 pr_info("nvram: Found too small %s partition," 298 " removing it...\n", part->name); 299 nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL); 300 p = 0; 301 } 302 303 /* Create one if we didn't find */ 304 if (!p) { 305 p = nvram_create_partition(part->name, NVRAM_SIG_OS, 306 part->req_size, part->min_size); 307 if (p == -ENOSPC) { 308 pr_info("nvram: No room to create %s partition, " 309 "deleting any obsolete OS partitions...\n", 310 part->name); 311 nvram_remove_partition(NULL, NVRAM_SIG_OS, 312 nvram_os_partitions); 313 p = nvram_create_partition(part->name, NVRAM_SIG_OS, 314 part->req_size, part->min_size); 315 } 316 } 317 318 if (p <= 0) { 319 pr_err("nvram: Failed to find or create %s" 320 " partition, err %d\n", part->name, (int)p); 321 return -1; 322 } 323 324 part->index = p; 325 part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info); 326 327 return 0; 328 } 329 330 /* Derived from logfs_compress() */ 331 static int nvram_compress(const void *in, void *out, size_t inlen, 332 size_t outlen) 333 { 334 int err, ret; 335 336 ret = -EIO; 337 err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS, 338 MEM_LEVEL, Z_DEFAULT_STRATEGY); 339 if (err != Z_OK) 340 goto error; 341 342 stream.next_in = in; 343 stream.avail_in = inlen; 344 stream.total_in = 0; 345 stream.next_out = out; 346 stream.avail_out = outlen; 347 stream.total_out = 0; 348 349 err = zlib_deflate(&stream, Z_FINISH); 350 if (err != Z_STREAM_END) 351 goto error; 352 353 err = zlib_deflateEnd(&stream); 354 if (err != Z_OK) 355 goto error; 356 357 if (stream.total_out >= stream.total_in) 358 goto error; 359 360 ret = stream.total_out; 361 error: 362 return ret; 363 } 364 365 /* Compress the text from big_oops_buf into oops_buf. */ 366 static int zip_oops(size_t text_len) 367 { 368 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf; 369 int zipped_len = nvram_compress(big_oops_buf, oops_data, text_len, 370 oops_data_sz); 371 if (zipped_len < 0) { 372 pr_err("nvram: compression failed; returned %d\n", zipped_len); 373 pr_err("nvram: logging uncompressed oops/panic report\n"); 374 return -1; 375 } 376 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION); 377 oops_hdr->report_length = cpu_to_be16(zipped_len); 378 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds()); 379 return 0; 380 } 381 382 #ifdef CONFIG_PSTORE 383 static int nvram_pstore_open(struct pstore_info *psi) 384 { 385 /* Reset the iterator to start reading partitions again */ 386 read_type = -1; 387 return 0; 388 } 389 390 /** 391 * nvram_pstore_write - pstore write callback for nvram 392 * @record: pstore record to write, with @id to be set 393 * 394 * Called by pstore_dump() when an oops or panic report is logged in the 395 * printk buffer. 396 * Returns 0 on successful write. 397 */ 398 static int nvram_pstore_write(struct pstore_record *record) 399 { 400 int rc; 401 unsigned int err_type = ERR_TYPE_KERNEL_PANIC; 402 struct oops_log_info *oops_hdr = (struct oops_log_info *) oops_buf; 403 404 /* part 1 has the recent messages from printk buffer */ 405 if (record->part > 1 || (record->type != PSTORE_TYPE_DMESG)) 406 return -1; 407 408 if (clobbering_unread_rtas_event()) 409 return -1; 410 411 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION); 412 oops_hdr->report_length = cpu_to_be16(record->size); 413 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds()); 414 415 if (record->compressed) 416 err_type = ERR_TYPE_KERNEL_PANIC_GZ; 417 418 rc = nvram_write_os_partition(&oops_log_partition, oops_buf, 419 (int) (sizeof(*oops_hdr) + record->size), err_type, 420 record->count); 421 422 if (rc != 0) 423 return rc; 424 425 record->id = record->part; 426 return 0; 427 } 428 429 /* 430 * Reads the oops/panic report, rtas, of-config and common partition. 431 * Returns the length of the data we read from each partition. 432 * Returns 0 if we've been called before. 433 */ 434 static ssize_t nvram_pstore_read(struct pstore_record *record) 435 { 436 struct oops_log_info *oops_hdr; 437 unsigned int err_type, id_no, size = 0; 438 struct nvram_os_partition *part = NULL; 439 char *buff = NULL; 440 int sig = 0; 441 loff_t p; 442 443 read_type++; 444 445 switch (nvram_type_ids[read_type]) { 446 case PSTORE_TYPE_DMESG: 447 part = &oops_log_partition; 448 record->type = PSTORE_TYPE_DMESG; 449 break; 450 case PSTORE_TYPE_PPC_COMMON: 451 sig = NVRAM_SIG_SYS; 452 part = &common_partition; 453 record->type = PSTORE_TYPE_PPC_COMMON; 454 record->id = PSTORE_TYPE_PPC_COMMON; 455 record->time.tv_sec = 0; 456 record->time.tv_nsec = 0; 457 break; 458 #ifdef CONFIG_PPC_PSERIES 459 case PSTORE_TYPE_PPC_RTAS: 460 part = &rtas_log_partition; 461 record->type = PSTORE_TYPE_PPC_RTAS; 462 record->time.tv_sec = last_rtas_event; 463 record->time.tv_nsec = 0; 464 break; 465 case PSTORE_TYPE_PPC_OF: 466 sig = NVRAM_SIG_OF; 467 part = &of_config_partition; 468 record->type = PSTORE_TYPE_PPC_OF; 469 record->id = PSTORE_TYPE_PPC_OF; 470 record->time.tv_sec = 0; 471 record->time.tv_nsec = 0; 472 break; 473 #endif 474 #ifdef CONFIG_PPC_POWERNV 475 case PSTORE_TYPE_PPC_OPAL: 476 sig = NVRAM_SIG_FW; 477 part = &skiboot_partition; 478 record->type = PSTORE_TYPE_PPC_OPAL; 479 record->id = PSTORE_TYPE_PPC_OPAL; 480 record->time.tv_sec = 0; 481 record->time.tv_nsec = 0; 482 break; 483 #endif 484 default: 485 return 0; 486 } 487 488 if (!part->os_partition) { 489 p = nvram_find_partition(part->name, sig, &size); 490 if (p <= 0) { 491 pr_err("nvram: Failed to find partition %s, " 492 "err %d\n", part->name, (int)p); 493 return 0; 494 } 495 part->index = p; 496 part->size = size; 497 } 498 499 buff = kmalloc(part->size, GFP_KERNEL); 500 501 if (!buff) 502 return -ENOMEM; 503 504 if (nvram_read_partition(part, buff, part->size, &err_type, &id_no)) { 505 kfree(buff); 506 return 0; 507 } 508 509 record->count = 0; 510 511 if (part->os_partition) 512 record->id = id_no; 513 514 if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) { 515 size_t length, hdr_size; 516 517 oops_hdr = (struct oops_log_info *)buff; 518 if (be16_to_cpu(oops_hdr->version) < OOPS_HDR_VERSION) { 519 /* Old format oops header had 2-byte record size */ 520 hdr_size = sizeof(u16); 521 length = be16_to_cpu(oops_hdr->version); 522 record->time.tv_sec = 0; 523 record->time.tv_nsec = 0; 524 } else { 525 hdr_size = sizeof(*oops_hdr); 526 length = be16_to_cpu(oops_hdr->report_length); 527 record->time.tv_sec = be64_to_cpu(oops_hdr->timestamp); 528 record->time.tv_nsec = 0; 529 } 530 record->buf = kmemdup(buff + hdr_size, length, GFP_KERNEL); 531 kfree(buff); 532 if (record->buf == NULL) 533 return -ENOMEM; 534 535 record->ecc_notice_size = 0; 536 if (err_type == ERR_TYPE_KERNEL_PANIC_GZ) 537 record->compressed = true; 538 else 539 record->compressed = false; 540 return length; 541 } 542 543 record->buf = buff; 544 return part->size; 545 } 546 547 static struct pstore_info nvram_pstore_info = { 548 .owner = THIS_MODULE, 549 .name = "nvram", 550 .flags = PSTORE_FLAGS_DMESG, 551 .open = nvram_pstore_open, 552 .read = nvram_pstore_read, 553 .write = nvram_pstore_write, 554 }; 555 556 static int nvram_pstore_init(void) 557 { 558 int rc = 0; 559 560 if (machine_is(pseries)) { 561 nvram_type_ids[2] = PSTORE_TYPE_PPC_RTAS; 562 nvram_type_ids[3] = PSTORE_TYPE_PPC_OF; 563 } else 564 nvram_type_ids[2] = PSTORE_TYPE_PPC_OPAL; 565 566 nvram_pstore_info.buf = oops_data; 567 nvram_pstore_info.bufsize = oops_data_sz; 568 569 spin_lock_init(&nvram_pstore_info.buf_lock); 570 571 rc = pstore_register(&nvram_pstore_info); 572 if (rc && (rc != -EPERM)) 573 /* Print error only when pstore.backend == nvram */ 574 pr_err("nvram: pstore_register() failed, returned %d. " 575 "Defaults to kmsg_dump\n", rc); 576 577 return rc; 578 } 579 #else 580 static int nvram_pstore_init(void) 581 { 582 return -1; 583 } 584 #endif 585 586 void __init nvram_init_oops_partition(int rtas_partition_exists) 587 { 588 int rc; 589 590 rc = nvram_init_os_partition(&oops_log_partition); 591 if (rc != 0) { 592 #ifdef CONFIG_PPC_PSERIES 593 if (!rtas_partition_exists) { 594 pr_err("nvram: Failed to initialize oops partition!"); 595 return; 596 } 597 pr_notice("nvram: Using %s partition to log both" 598 " RTAS errors and oops/panic reports\n", 599 rtas_log_partition.name); 600 memcpy(&oops_log_partition, &rtas_log_partition, 601 sizeof(rtas_log_partition)); 602 #else 603 pr_err("nvram: Failed to initialize oops partition!"); 604 return; 605 #endif 606 } 607 oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL); 608 if (!oops_buf) { 609 pr_err("nvram: No memory for %s partition\n", 610 oops_log_partition.name); 611 return; 612 } 613 oops_data = oops_buf + sizeof(struct oops_log_info); 614 oops_data_sz = oops_log_partition.size - sizeof(struct oops_log_info); 615 616 rc = nvram_pstore_init(); 617 618 if (!rc) 619 return; 620 621 /* 622 * Figure compression (preceded by elimination of each line's <n> 623 * severity prefix) will reduce the oops/panic report to at most 624 * 45% of its original size. 625 */ 626 big_oops_buf_sz = (oops_data_sz * 100) / 45; 627 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); 628 if (big_oops_buf) { 629 stream.workspace = kmalloc(zlib_deflate_workspacesize( 630 WINDOW_BITS, MEM_LEVEL), GFP_KERNEL); 631 if (!stream.workspace) { 632 pr_err("nvram: No memory for compression workspace; " 633 "skipping compression of %s partition data\n", 634 oops_log_partition.name); 635 kfree(big_oops_buf); 636 big_oops_buf = NULL; 637 } 638 } else { 639 pr_err("No memory for uncompressed %s data; " 640 "skipping compression\n", oops_log_partition.name); 641 stream.workspace = NULL; 642 } 643 644 rc = kmsg_dump_register(&nvram_kmsg_dumper); 645 if (rc != 0) { 646 pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc); 647 kfree(oops_buf); 648 kfree(big_oops_buf); 649 kfree(stream.workspace); 650 } 651 } 652 653 /* 654 * This is our kmsg_dump callback, called after an oops or panic report 655 * has been written to the printk buffer. We want to capture as much 656 * of the printk buffer as possible. First, capture as much as we can 657 * that we think will compress sufficiently to fit in the lnx,oops-log 658 * partition. If that's too much, go back and capture uncompressed text. 659 */ 660 static void oops_to_nvram(struct kmsg_dumper *dumper, 661 enum kmsg_dump_reason reason) 662 { 663 struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf; 664 static unsigned int oops_count = 0; 665 static bool panicking = false; 666 static DEFINE_SPINLOCK(lock); 667 unsigned long flags; 668 size_t text_len; 669 unsigned int err_type = ERR_TYPE_KERNEL_PANIC_GZ; 670 int rc = -1; 671 672 switch (reason) { 673 case KMSG_DUMP_RESTART: 674 case KMSG_DUMP_HALT: 675 case KMSG_DUMP_POWEROFF: 676 /* These are almost always orderly shutdowns. */ 677 return; 678 case KMSG_DUMP_OOPS: 679 break; 680 case KMSG_DUMP_PANIC: 681 panicking = true; 682 break; 683 case KMSG_DUMP_EMERG: 684 if (panicking) 685 /* Panic report already captured. */ 686 return; 687 break; 688 default: 689 pr_err("%s: ignoring unrecognized KMSG_DUMP_* reason %d\n", 690 __func__, (int) reason); 691 return; 692 } 693 694 if (clobbering_unread_rtas_event()) 695 return; 696 697 if (!spin_trylock_irqsave(&lock, flags)) 698 return; 699 700 if (big_oops_buf) { 701 kmsg_dump_get_buffer(dumper, false, 702 big_oops_buf, big_oops_buf_sz, &text_len); 703 rc = zip_oops(text_len); 704 } 705 if (rc != 0) { 706 kmsg_dump_rewind(dumper); 707 kmsg_dump_get_buffer(dumper, false, 708 oops_data, oops_data_sz, &text_len); 709 err_type = ERR_TYPE_KERNEL_PANIC; 710 oops_hdr->version = cpu_to_be16(OOPS_HDR_VERSION); 711 oops_hdr->report_length = cpu_to_be16(text_len); 712 oops_hdr->timestamp = cpu_to_be64(ktime_get_real_seconds()); 713 } 714 715 (void) nvram_write_os_partition(&oops_log_partition, oops_buf, 716 (int) (sizeof(*oops_hdr) + text_len), err_type, 717 ++oops_count); 718 719 spin_unlock_irqrestore(&lock, flags); 720 } 721 722 static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin) 723 { 724 if (ppc_md.nvram_size == NULL) 725 return -ENODEV; 726 return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE, 727 ppc_md.nvram_size()); 728 } 729 730 731 static ssize_t dev_nvram_read(struct file *file, char __user *buf, 732 size_t count, loff_t *ppos) 733 { 734 ssize_t ret; 735 char *tmp = NULL; 736 ssize_t size; 737 738 if (!ppc_md.nvram_size) { 739 ret = -ENODEV; 740 goto out; 741 } 742 743 size = ppc_md.nvram_size(); 744 if (size < 0) { 745 ret = size; 746 goto out; 747 } 748 749 if (*ppos >= size) { 750 ret = 0; 751 goto out; 752 } 753 754 count = min_t(size_t, count, size - *ppos); 755 count = min(count, PAGE_SIZE); 756 757 tmp = kmalloc(count, GFP_KERNEL); 758 if (!tmp) { 759 ret = -ENOMEM; 760 goto out; 761 } 762 763 ret = ppc_md.nvram_read(tmp, count, ppos); 764 if (ret <= 0) 765 goto out; 766 767 if (copy_to_user(buf, tmp, ret)) 768 ret = -EFAULT; 769 770 out: 771 kfree(tmp); 772 return ret; 773 774 } 775 776 static ssize_t dev_nvram_write(struct file *file, const char __user *buf, 777 size_t count, loff_t *ppos) 778 { 779 ssize_t ret; 780 char *tmp = NULL; 781 ssize_t size; 782 783 ret = -ENODEV; 784 if (!ppc_md.nvram_size) 785 goto out; 786 787 ret = 0; 788 size = ppc_md.nvram_size(); 789 if (*ppos >= size || size < 0) 790 goto out; 791 792 count = min_t(size_t, count, size - *ppos); 793 count = min(count, PAGE_SIZE); 794 795 ret = -ENOMEM; 796 tmp = kmalloc(count, GFP_KERNEL); 797 if (!tmp) 798 goto out; 799 800 ret = -EFAULT; 801 if (copy_from_user(tmp, buf, count)) 802 goto out; 803 804 ret = ppc_md.nvram_write(tmp, count, ppos); 805 806 out: 807 kfree(tmp); 808 return ret; 809 810 } 811 812 static long dev_nvram_ioctl(struct file *file, unsigned int cmd, 813 unsigned long arg) 814 { 815 switch(cmd) { 816 #ifdef CONFIG_PPC_PMAC 817 case OBSOLETE_PMAC_NVRAM_GET_OFFSET: 818 printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); 819 case IOC_NVRAM_GET_OFFSET: { 820 int part, offset; 821 822 if (!machine_is(powermac)) 823 return -EINVAL; 824 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) 825 return -EFAULT; 826 if (part < pmac_nvram_OF || part > pmac_nvram_NR) 827 return -EINVAL; 828 offset = pmac_get_partition(part); 829 if (offset < 0) 830 return offset; 831 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) 832 return -EFAULT; 833 return 0; 834 } 835 #endif /* CONFIG_PPC_PMAC */ 836 default: 837 return -EINVAL; 838 } 839 } 840 841 static const struct file_operations nvram_fops = { 842 .owner = THIS_MODULE, 843 .llseek = dev_nvram_llseek, 844 .read = dev_nvram_read, 845 .write = dev_nvram_write, 846 .unlocked_ioctl = dev_nvram_ioctl, 847 }; 848 849 static struct miscdevice nvram_dev = { 850 NVRAM_MINOR, 851 "nvram", 852 &nvram_fops 853 }; 854 855 856 #ifdef DEBUG_NVRAM 857 static void __init nvram_print_partitions(char * label) 858 { 859 struct nvram_partition * tmp_part; 860 861 printk(KERN_WARNING "--------%s---------\n", label); 862 printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n"); 863 list_for_each_entry(tmp_part, &nvram_partitions, partition) { 864 printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%12.12s\n", 865 tmp_part->index, tmp_part->header.signature, 866 tmp_part->header.checksum, tmp_part->header.length, 867 tmp_part->header.name); 868 } 869 } 870 #endif 871 872 873 static int __init nvram_write_header(struct nvram_partition * part) 874 { 875 loff_t tmp_index; 876 int rc; 877 struct nvram_header phead; 878 879 memcpy(&phead, &part->header, NVRAM_HEADER_LEN); 880 phead.length = cpu_to_be16(phead.length); 881 882 tmp_index = part->index; 883 rc = ppc_md.nvram_write((char *)&phead, NVRAM_HEADER_LEN, &tmp_index); 884 885 return rc; 886 } 887 888 889 static unsigned char __init nvram_checksum(struct nvram_header *p) 890 { 891 unsigned int c_sum, c_sum2; 892 unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */ 893 c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5]; 894 895 /* The sum may have spilled into the 3rd byte. Fold it back. */ 896 c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff; 897 /* The sum cannot exceed 2 bytes. Fold it into a checksum */ 898 c_sum2 = (c_sum >> 8) + (c_sum << 8); 899 c_sum = ((c_sum + c_sum2) >> 8) & 0xff; 900 return c_sum; 901 } 902 903 /* 904 * Per the criteria passed via nvram_remove_partition(), should this 905 * partition be removed? 1=remove, 0=keep 906 */ 907 static int nvram_can_remove_partition(struct nvram_partition *part, 908 const char *name, int sig, const char *exceptions[]) 909 { 910 if (part->header.signature != sig) 911 return 0; 912 if (name) { 913 if (strncmp(name, part->header.name, 12)) 914 return 0; 915 } else if (exceptions) { 916 const char **except; 917 for (except = exceptions; *except; except++) { 918 if (!strncmp(*except, part->header.name, 12)) 919 return 0; 920 } 921 } 922 return 1; 923 } 924 925 /** 926 * nvram_remove_partition - Remove one or more partitions in nvram 927 * @name: name of the partition to remove, or NULL for a 928 * signature only match 929 * @sig: signature of the partition(s) to remove 930 * @exceptions: When removing all partitions with a matching signature, 931 * leave these alone. 932 */ 933 934 int __init nvram_remove_partition(const char *name, int sig, 935 const char *exceptions[]) 936 { 937 struct nvram_partition *part, *prev, *tmp; 938 int rc; 939 940 list_for_each_entry(part, &nvram_partitions, partition) { 941 if (!nvram_can_remove_partition(part, name, sig, exceptions)) 942 continue; 943 944 /* Make partition a free partition */ 945 part->header.signature = NVRAM_SIG_FREE; 946 memset(part->header.name, 'w', 12); 947 part->header.checksum = nvram_checksum(&part->header); 948 rc = nvram_write_header(part); 949 if (rc <= 0) { 950 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc); 951 return rc; 952 } 953 } 954 955 /* Merge contiguous ones */ 956 prev = NULL; 957 list_for_each_entry_safe(part, tmp, &nvram_partitions, partition) { 958 if (part->header.signature != NVRAM_SIG_FREE) { 959 prev = NULL; 960 continue; 961 } 962 if (prev) { 963 prev->header.length += part->header.length; 964 prev->header.checksum = nvram_checksum(&prev->header); 965 rc = nvram_write_header(prev); 966 if (rc <= 0) { 967 printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc); 968 return rc; 969 } 970 list_del(&part->partition); 971 kfree(part); 972 } else 973 prev = part; 974 } 975 976 return 0; 977 } 978 979 /** 980 * nvram_create_partition - Create a partition in nvram 981 * @name: name of the partition to create 982 * @sig: signature of the partition to create 983 * @req_size: size of data to allocate in bytes 984 * @min_size: minimum acceptable size (0 means req_size) 985 * 986 * Returns a negative error code or a positive nvram index 987 * of the beginning of the data area of the newly created 988 * partition. If you provided a min_size smaller than req_size 989 * you need to query for the actual size yourself after the 990 * call using nvram_partition_get_size(). 991 */ 992 loff_t __init nvram_create_partition(const char *name, int sig, 993 int req_size, int min_size) 994 { 995 struct nvram_partition *part; 996 struct nvram_partition *new_part; 997 struct nvram_partition *free_part = NULL; 998 static char nv_init_vals[16]; 999 loff_t tmp_index; 1000 long size = 0; 1001 int rc; 1002 1003 /* Convert sizes from bytes to blocks */ 1004 req_size = _ALIGN_UP(req_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN; 1005 min_size = _ALIGN_UP(min_size, NVRAM_BLOCK_LEN) / NVRAM_BLOCK_LEN; 1006 1007 /* If no minimum size specified, make it the same as the 1008 * requested size 1009 */ 1010 if (min_size == 0) 1011 min_size = req_size; 1012 if (min_size > req_size) 1013 return -EINVAL; 1014 1015 /* Now add one block to each for the header */ 1016 req_size += 1; 1017 min_size += 1; 1018 1019 /* Find a free partition that will give us the maximum needed size 1020 If can't find one that will give us the minimum size needed */ 1021 list_for_each_entry(part, &nvram_partitions, partition) { 1022 if (part->header.signature != NVRAM_SIG_FREE) 1023 continue; 1024 1025 if (part->header.length >= req_size) { 1026 size = req_size; 1027 free_part = part; 1028 break; 1029 } 1030 if (part->header.length > size && 1031 part->header.length >= min_size) { 1032 size = part->header.length; 1033 free_part = part; 1034 } 1035 } 1036 if (!size) 1037 return -ENOSPC; 1038 1039 /* Create our OS partition */ 1040 new_part = kmalloc(sizeof(*new_part), GFP_KERNEL); 1041 if (!new_part) { 1042 pr_err("%s: kmalloc failed\n", __func__); 1043 return -ENOMEM; 1044 } 1045 1046 new_part->index = free_part->index; 1047 new_part->header.signature = sig; 1048 new_part->header.length = size; 1049 strncpy(new_part->header.name, name, 12); 1050 new_part->header.checksum = nvram_checksum(&new_part->header); 1051 1052 rc = nvram_write_header(new_part); 1053 if (rc <= 0) { 1054 pr_err("%s: nvram_write_header failed (%d)\n", __func__, rc); 1055 kfree(new_part); 1056 return rc; 1057 } 1058 list_add_tail(&new_part->partition, &free_part->partition); 1059 1060 /* Adjust or remove the partition we stole the space from */ 1061 if (free_part->header.length > size) { 1062 free_part->index += size * NVRAM_BLOCK_LEN; 1063 free_part->header.length -= size; 1064 free_part->header.checksum = nvram_checksum(&free_part->header); 1065 rc = nvram_write_header(free_part); 1066 if (rc <= 0) { 1067 pr_err("%s: nvram_write_header failed (%d)\n", 1068 __func__, rc); 1069 return rc; 1070 } 1071 } else { 1072 list_del(&free_part->partition); 1073 kfree(free_part); 1074 } 1075 1076 /* Clear the new partition */ 1077 for (tmp_index = new_part->index + NVRAM_HEADER_LEN; 1078 tmp_index < ((size - 1) * NVRAM_BLOCK_LEN); 1079 tmp_index += NVRAM_BLOCK_LEN) { 1080 rc = ppc_md.nvram_write(nv_init_vals, NVRAM_BLOCK_LEN, &tmp_index); 1081 if (rc <= 0) { 1082 pr_err("%s: nvram_write failed (%d)\n", 1083 __func__, rc); 1084 return rc; 1085 } 1086 } 1087 1088 return new_part->index + NVRAM_HEADER_LEN; 1089 } 1090 1091 /** 1092 * nvram_get_partition_size - Get the data size of an nvram partition 1093 * @data_index: This is the offset of the start of the data of 1094 * the partition. The same value that is returned by 1095 * nvram_create_partition(). 1096 */ 1097 int nvram_get_partition_size(loff_t data_index) 1098 { 1099 struct nvram_partition *part; 1100 1101 list_for_each_entry(part, &nvram_partitions, partition) { 1102 if (part->index + NVRAM_HEADER_LEN == data_index) 1103 return (part->header.length - 1) * NVRAM_BLOCK_LEN; 1104 } 1105 return -1; 1106 } 1107 1108 1109 /** 1110 * nvram_find_partition - Find an nvram partition by signature and name 1111 * @name: Name of the partition or NULL for any name 1112 * @sig: Signature to test against 1113 * @out_size: if non-NULL, returns the size of the data part of the partition 1114 */ 1115 loff_t nvram_find_partition(const char *name, int sig, int *out_size) 1116 { 1117 struct nvram_partition *p; 1118 1119 list_for_each_entry(p, &nvram_partitions, partition) { 1120 if (p->header.signature == sig && 1121 (!name || !strncmp(p->header.name, name, 12))) { 1122 if (out_size) 1123 *out_size = (p->header.length - 1) * 1124 NVRAM_BLOCK_LEN; 1125 return p->index + NVRAM_HEADER_LEN; 1126 } 1127 } 1128 return 0; 1129 } 1130 1131 int __init nvram_scan_partitions(void) 1132 { 1133 loff_t cur_index = 0; 1134 struct nvram_header phead; 1135 struct nvram_partition * tmp_part; 1136 unsigned char c_sum; 1137 char * header; 1138 int total_size; 1139 int err; 1140 1141 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0) 1142 return -ENODEV; 1143 total_size = ppc_md.nvram_size(); 1144 1145 header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL); 1146 if (!header) { 1147 printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n"); 1148 return -ENOMEM; 1149 } 1150 1151 while (cur_index < total_size) { 1152 1153 err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index); 1154 if (err != NVRAM_HEADER_LEN) { 1155 printk(KERN_ERR "nvram_scan_partitions: Error parsing " 1156 "nvram partitions\n"); 1157 goto out; 1158 } 1159 1160 cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */ 1161 1162 memcpy(&phead, header, NVRAM_HEADER_LEN); 1163 1164 phead.length = be16_to_cpu(phead.length); 1165 1166 err = 0; 1167 c_sum = nvram_checksum(&phead); 1168 if (c_sum != phead.checksum) { 1169 printk(KERN_WARNING "WARNING: nvram partition checksum" 1170 " was %02x, should be %02x!\n", 1171 phead.checksum, c_sum); 1172 printk(KERN_WARNING "Terminating nvram partition scan\n"); 1173 goto out; 1174 } 1175 if (!phead.length) { 1176 printk(KERN_WARNING "WARNING: nvram corruption " 1177 "detected: 0-length partition\n"); 1178 goto out; 1179 } 1180 tmp_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); 1181 err = -ENOMEM; 1182 if (!tmp_part) { 1183 printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n"); 1184 goto out; 1185 } 1186 1187 memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN); 1188 tmp_part->index = cur_index; 1189 list_add_tail(&tmp_part->partition, &nvram_partitions); 1190 1191 cur_index += phead.length * NVRAM_BLOCK_LEN; 1192 } 1193 err = 0; 1194 1195 #ifdef DEBUG_NVRAM 1196 nvram_print_partitions("NVRAM Partitions"); 1197 #endif 1198 1199 out: 1200 kfree(header); 1201 return err; 1202 } 1203 1204 static int __init nvram_init(void) 1205 { 1206 int rc; 1207 1208 BUILD_BUG_ON(NVRAM_BLOCK_LEN != 16); 1209 1210 if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0) 1211 return -ENODEV; 1212 1213 rc = misc_register(&nvram_dev); 1214 if (rc != 0) { 1215 printk(KERN_ERR "nvram_init: failed to register device\n"); 1216 return rc; 1217 } 1218 1219 return rc; 1220 } 1221 device_initcall(nvram_init); 1222