1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash 4 * dump with assistance from firmware. This approach does not use kexec, 5 * instead firmware assists in booting the kdump kernel while preserving 6 * memory contents. The most of the code implementation has been adapted 7 * from phyp assisted dump implementation written by Linas Vepstas and 8 * Manish Ahuja 9 * 10 * Copyright 2011 IBM Corporation 11 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 12 */ 13 14 #undef DEBUG 15 #define pr_fmt(fmt) "fadump: " fmt 16 17 #include <linux/string.h> 18 #include <linux/memblock.h> 19 #include <linux/delay.h> 20 #include <linux/seq_file.h> 21 #include <linux/crash_dump.h> 22 #include <linux/kobject.h> 23 #include <linux/sysfs.h> 24 #include <linux/slab.h> 25 #include <linux/cma.h> 26 #include <linux/hugetlb.h> 27 #include <linux/debugfs.h> 28 #include <linux/of.h> 29 #include <linux/of_fdt.h> 30 31 #include <asm/page.h> 32 #include <asm/fadump.h> 33 #include <asm/fadump-internal.h> 34 #include <asm/setup.h> 35 #include <asm/interrupt.h> 36 37 /* 38 * The CPU who acquired the lock to trigger the fadump crash should 39 * wait for other CPUs to enter. 40 * 41 * The timeout is in milliseconds. 42 */ 43 #define CRASH_TIMEOUT 500 44 45 static struct fw_dump fw_dump; 46 47 static void __init fadump_reserve_crash_area(u64 base); 48 49 #ifndef CONFIG_PRESERVE_FA_DUMP 50 51 static struct kobject *fadump_kobj; 52 53 static atomic_t cpus_in_fadump; 54 static DEFINE_MUTEX(fadump_mutex); 55 56 static struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0, false }; 57 58 #define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */ 59 #define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \ 60 sizeof(struct fadump_memory_range)) 61 static struct fadump_memory_range rngs[RESERVED_RNGS_CNT]; 62 static struct fadump_mrange_info 63 reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true }; 64 65 static void __init early_init_dt_scan_reserved_ranges(unsigned long node); 66 67 #ifdef CONFIG_CMA 68 static struct cma *fadump_cma; 69 70 /* 71 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory 72 * 73 * This function initializes CMA area from fadump reserved memory. 74 * The total size of fadump reserved memory covers for boot memory size 75 * + cpu data size + hpte size and metadata. 76 * Initialize only the area equivalent to boot memory size for CMA use. 77 * The remaining portion of fadump reserved memory will be not given 78 * to CMA and pages for those will stay reserved. boot memory size is 79 * aligned per CMA requirement to satisy cma_init_reserved_mem() call. 80 * But for some reason even if it fails we still have the memory reservation 81 * with us and we can still continue doing fadump. 82 */ 83 static int __init fadump_cma_init(void) 84 { 85 unsigned long long base, size; 86 int rc; 87 88 if (!fw_dump.fadump_enabled) 89 return 0; 90 91 /* 92 * Do not use CMA if user has provided fadump=nocma kernel parameter. 93 * Return 1 to continue with fadump old behaviour. 94 */ 95 if (fw_dump.nocma) 96 return 1; 97 98 base = fw_dump.reserve_dump_area_start; 99 size = fw_dump.boot_memory_size; 100 101 if (!size) 102 return 0; 103 104 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma); 105 if (rc) { 106 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc); 107 /* 108 * Though the CMA init has failed we still have memory 109 * reservation with us. The reserved memory will be 110 * blocked from production system usage. Hence return 1, 111 * so that we can continue with fadump. 112 */ 113 return 1; 114 } 115 116 /* 117 * If CMA activation fails, keep the pages reserved, instead of 118 * exposing them to buddy allocator. Same as 'fadump=nocma' case. 119 */ 120 cma_reserve_pages_on_error(fadump_cma); 121 122 /* 123 * So we now have successfully initialized cma area for fadump. 124 */ 125 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx " 126 "bytes of memory reserved for firmware-assisted dump\n", 127 cma_get_size(fadump_cma), 128 (unsigned long)cma_get_base(fadump_cma) >> 20, 129 fw_dump.reserve_dump_area_size); 130 return 1; 131 } 132 #else 133 static int __init fadump_cma_init(void) { return 1; } 134 #endif /* CONFIG_CMA */ 135 136 /* Scan the Firmware Assisted dump configuration details. */ 137 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname, 138 int depth, void *data) 139 { 140 if (depth == 0) { 141 early_init_dt_scan_reserved_ranges(node); 142 return 0; 143 } 144 145 if (depth != 1) 146 return 0; 147 148 if (strcmp(uname, "rtas") == 0) { 149 rtas_fadump_dt_scan(&fw_dump, node); 150 return 1; 151 } 152 153 if (strcmp(uname, "ibm,opal") == 0) { 154 opal_fadump_dt_scan(&fw_dump, node); 155 return 1; 156 } 157 158 return 0; 159 } 160 161 /* 162 * If fadump is registered, check if the memory provided 163 * falls within boot memory area and reserved memory area. 164 */ 165 int is_fadump_memory_area(u64 addr, unsigned long size) 166 { 167 u64 d_start, d_end; 168 169 if (!fw_dump.dump_registered) 170 return 0; 171 172 if (!size) 173 return 0; 174 175 d_start = fw_dump.reserve_dump_area_start; 176 d_end = d_start + fw_dump.reserve_dump_area_size; 177 if (((addr + size) > d_start) && (addr <= d_end)) 178 return 1; 179 180 return (addr <= fw_dump.boot_mem_top); 181 } 182 183 int should_fadump_crash(void) 184 { 185 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 186 return 0; 187 return 1; 188 } 189 190 int is_fadump_active(void) 191 { 192 return fw_dump.dump_active; 193 } 194 195 /* 196 * Returns true, if there are no holes in memory area between d_start to d_end, 197 * false otherwise. 198 */ 199 static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end) 200 { 201 phys_addr_t reg_start, reg_end; 202 bool ret = false; 203 u64 i, start, end; 204 205 for_each_mem_range(i, ®_start, ®_end) { 206 start = max_t(u64, d_start, reg_start); 207 end = min_t(u64, d_end, reg_end); 208 if (d_start < end) { 209 /* Memory hole from d_start to start */ 210 if (start > d_start) 211 break; 212 213 if (end == d_end) { 214 ret = true; 215 break; 216 } 217 218 d_start = end + 1; 219 } 220 } 221 222 return ret; 223 } 224 225 /* 226 * Returns true, if there are no holes in boot memory area, 227 * false otherwise. 228 */ 229 bool is_fadump_boot_mem_contiguous(void) 230 { 231 unsigned long d_start, d_end; 232 bool ret = false; 233 int i; 234 235 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 236 d_start = fw_dump.boot_mem_addr[i]; 237 d_end = d_start + fw_dump.boot_mem_sz[i]; 238 239 ret = is_fadump_mem_area_contiguous(d_start, d_end); 240 if (!ret) 241 break; 242 } 243 244 return ret; 245 } 246 247 /* 248 * Returns true, if there are no holes in reserved memory area, 249 * false otherwise. 250 */ 251 bool is_fadump_reserved_mem_contiguous(void) 252 { 253 u64 d_start, d_end; 254 255 d_start = fw_dump.reserve_dump_area_start; 256 d_end = d_start + fw_dump.reserve_dump_area_size; 257 return is_fadump_mem_area_contiguous(d_start, d_end); 258 } 259 260 /* Print firmware assisted dump configurations for debugging purpose. */ 261 static void __init fadump_show_config(void) 262 { 263 int i; 264 265 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 266 (fw_dump.fadump_supported ? "present" : "no support")); 267 268 if (!fw_dump.fadump_supported) 269 return; 270 271 pr_debug("Fadump enabled : %s\n", 272 (fw_dump.fadump_enabled ? "yes" : "no")); 273 pr_debug("Dump Active : %s\n", 274 (fw_dump.dump_active ? "yes" : "no")); 275 pr_debug("Dump section sizes:\n"); 276 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 277 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 278 pr_debug(" Boot memory size : %lx\n", fw_dump.boot_memory_size); 279 pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top); 280 pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt); 281 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 282 pr_debug("[%03d] base = %llx, size = %llx\n", i, 283 fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]); 284 } 285 } 286 287 /** 288 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 289 * 290 * Function to find the largest memory size we need to reserve during early 291 * boot process. This will be the size of the memory that is required for a 292 * kernel to boot successfully. 293 * 294 * This function has been taken from phyp-assisted dump feature implementation. 295 * 296 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 297 * 298 * TODO: Come up with better approach to find out more accurate memory size 299 * that is required for a kernel to boot successfully. 300 * 301 */ 302 static __init u64 fadump_calculate_reserve_size(void) 303 { 304 u64 base, size, bootmem_min; 305 int ret; 306 307 if (fw_dump.reserve_bootvar) 308 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 309 310 /* 311 * Check if the size is specified through crashkernel= cmdline 312 * option. If yes, then use that but ignore base as fadump reserves 313 * memory at a predefined offset. 314 */ 315 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 316 &size, &base); 317 if (ret == 0 && size > 0) { 318 unsigned long max_size; 319 320 if (fw_dump.reserve_bootvar) 321 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 322 323 fw_dump.reserve_bootvar = (unsigned long)size; 324 325 /* 326 * Adjust if the boot memory size specified is above 327 * the upper limit. 328 */ 329 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 330 if (fw_dump.reserve_bootvar > max_size) { 331 fw_dump.reserve_bootvar = max_size; 332 pr_info("Adjusted boot memory size to %luMB\n", 333 (fw_dump.reserve_bootvar >> 20)); 334 } 335 336 return fw_dump.reserve_bootvar; 337 } else if (fw_dump.reserve_bootvar) { 338 /* 339 * 'fadump_reserve_mem=' is being used to reserve memory 340 * for firmware-assisted dump. 341 */ 342 return fw_dump.reserve_bootvar; 343 } 344 345 /* divide by 20 to get 5% of value */ 346 size = memblock_phys_mem_size() / 20; 347 348 /* round it down in multiples of 256 */ 349 size = size & ~0x0FFFFFFFUL; 350 351 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 352 if (memory_limit && size > memory_limit) 353 size = memory_limit; 354 355 bootmem_min = fw_dump.ops->fadump_get_bootmem_min(); 356 return (size > bootmem_min ? size : bootmem_min); 357 } 358 359 /* 360 * Calculate the total memory size required to be reserved for 361 * firmware-assisted dump registration. 362 */ 363 static unsigned long __init get_fadump_area_size(void) 364 { 365 unsigned long size = 0; 366 367 size += fw_dump.cpu_state_data_size; 368 size += fw_dump.hpte_region_size; 369 /* 370 * Account for pagesize alignment of boot memory area destination address. 371 * This faciliates in mmap reading of first kernel's memory. 372 */ 373 size = PAGE_ALIGN(size); 374 size += fw_dump.boot_memory_size; 375 size += sizeof(struct fadump_crash_info_header); 376 size += sizeof(struct elfhdr); /* ELF core header.*/ 377 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 378 /* Program headers for crash memory regions. */ 379 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 380 381 size = PAGE_ALIGN(size); 382 383 /* This is to hold kernel metadata on platforms that support it */ 384 size += (fw_dump.ops->fadump_get_metadata_size ? 385 fw_dump.ops->fadump_get_metadata_size() : 0); 386 return size; 387 } 388 389 static int __init add_boot_mem_region(unsigned long rstart, 390 unsigned long rsize) 391 { 392 int i = fw_dump.boot_mem_regs_cnt++; 393 394 if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) { 395 fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS; 396 return 0; 397 } 398 399 pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n", 400 i, rstart, (rstart + rsize)); 401 fw_dump.boot_mem_addr[i] = rstart; 402 fw_dump.boot_mem_sz[i] = rsize; 403 return 1; 404 } 405 406 /* 407 * Firmware usually has a hard limit on the data it can copy per region. 408 * Honour that by splitting a memory range into multiple regions. 409 */ 410 static int __init add_boot_mem_regions(unsigned long mstart, 411 unsigned long msize) 412 { 413 unsigned long rstart, rsize, max_size; 414 int ret = 1; 415 416 rstart = mstart; 417 max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize; 418 while (msize) { 419 if (msize > max_size) 420 rsize = max_size; 421 else 422 rsize = msize; 423 424 ret = add_boot_mem_region(rstart, rsize); 425 if (!ret) 426 break; 427 428 msize -= rsize; 429 rstart += rsize; 430 } 431 432 return ret; 433 } 434 435 static int __init fadump_get_boot_mem_regions(void) 436 { 437 unsigned long size, cur_size, hole_size, last_end; 438 unsigned long mem_size = fw_dump.boot_memory_size; 439 phys_addr_t reg_start, reg_end; 440 int ret = 1; 441 u64 i; 442 443 fw_dump.boot_mem_regs_cnt = 0; 444 445 last_end = 0; 446 hole_size = 0; 447 cur_size = 0; 448 for_each_mem_range(i, ®_start, ®_end) { 449 size = reg_end - reg_start; 450 hole_size += (reg_start - last_end); 451 452 if ((cur_size + size) >= mem_size) { 453 size = (mem_size - cur_size); 454 ret = add_boot_mem_regions(reg_start, size); 455 break; 456 } 457 458 mem_size -= size; 459 cur_size += size; 460 ret = add_boot_mem_regions(reg_start, size); 461 if (!ret) 462 break; 463 464 last_end = reg_end; 465 } 466 fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size); 467 468 return ret; 469 } 470 471 /* 472 * Returns true, if the given range overlaps with reserved memory ranges 473 * starting at idx. Also, updates idx to index of overlapping memory range 474 * with the given memory range. 475 * False, otherwise. 476 */ 477 static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx) 478 { 479 bool ret = false; 480 int i; 481 482 for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) { 483 u64 rbase = reserved_mrange_info.mem_ranges[i].base; 484 u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size; 485 486 if (end <= rbase) 487 break; 488 489 if ((end > rbase) && (base < rend)) { 490 *idx = i; 491 ret = true; 492 break; 493 } 494 } 495 496 return ret; 497 } 498 499 /* 500 * Locate a suitable memory area to reserve memory for FADump. While at it, 501 * lookup reserved-ranges & avoid overlap with them, as they are used by F/W. 502 */ 503 static u64 __init fadump_locate_reserve_mem(u64 base, u64 size) 504 { 505 struct fadump_memory_range *mrngs; 506 phys_addr_t mstart, mend; 507 int idx = 0; 508 u64 i, ret = 0; 509 510 mrngs = reserved_mrange_info.mem_ranges; 511 for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, 512 &mstart, &mend, NULL) { 513 pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n", 514 i, mstart, mend, base); 515 516 if (mstart > base) 517 base = PAGE_ALIGN(mstart); 518 519 while ((mend > base) && ((mend - base) >= size)) { 520 if (!overlaps_reserved_ranges(base, base+size, &idx)) { 521 ret = base; 522 goto out; 523 } 524 525 base = mrngs[idx].base + mrngs[idx].size; 526 base = PAGE_ALIGN(base); 527 } 528 } 529 530 out: 531 return ret; 532 } 533 534 int __init fadump_reserve_mem(void) 535 { 536 u64 base, size, mem_boundary, bootmem_min; 537 int ret = 1; 538 539 if (!fw_dump.fadump_enabled) 540 return 0; 541 542 if (!fw_dump.fadump_supported) { 543 pr_info("Firmware-Assisted Dump is not supported on this hardware\n"); 544 goto error_out; 545 } 546 547 /* 548 * Initialize boot memory size 549 * If dump is active then we have already calculated the size during 550 * first kernel. 551 */ 552 if (!fw_dump.dump_active) { 553 fw_dump.boot_memory_size = 554 PAGE_ALIGN(fadump_calculate_reserve_size()); 555 #ifdef CONFIG_CMA 556 if (!fw_dump.nocma) { 557 fw_dump.boot_memory_size = 558 ALIGN(fw_dump.boot_memory_size, 559 CMA_MIN_ALIGNMENT_BYTES); 560 } 561 #endif 562 563 bootmem_min = fw_dump.ops->fadump_get_bootmem_min(); 564 if (fw_dump.boot_memory_size < bootmem_min) { 565 pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n", 566 fw_dump.boot_memory_size, bootmem_min); 567 goto error_out; 568 } 569 570 if (!fadump_get_boot_mem_regions()) { 571 pr_err("Too many holes in boot memory area to enable fadump\n"); 572 goto error_out; 573 } 574 } 575 576 /* 577 * Calculate the memory boundary. 578 * If memory_limit is less than actual memory boundary then reserve 579 * the memory for fadump beyond the memory_limit and adjust the 580 * memory_limit accordingly, so that the running kernel can run with 581 * specified memory_limit. 582 */ 583 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 584 size = get_fadump_area_size(); 585 if ((memory_limit + size) < memblock_end_of_DRAM()) 586 memory_limit += size; 587 else 588 memory_limit = memblock_end_of_DRAM(); 589 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 590 " dump, now %#016llx\n", memory_limit); 591 } 592 if (memory_limit) 593 mem_boundary = memory_limit; 594 else 595 mem_boundary = memblock_end_of_DRAM(); 596 597 base = fw_dump.boot_mem_top; 598 size = get_fadump_area_size(); 599 fw_dump.reserve_dump_area_size = size; 600 if (fw_dump.dump_active) { 601 pr_info("Firmware-assisted dump is active.\n"); 602 603 #ifdef CONFIG_HUGETLB_PAGE 604 /* 605 * FADump capture kernel doesn't care much about hugepages. 606 * In fact, handling hugepages in capture kernel is asking for 607 * trouble. So, disable HugeTLB support when fadump is active. 608 */ 609 hugetlb_disabled = true; 610 #endif 611 /* 612 * If last boot has crashed then reserve all the memory 613 * above boot memory size so that we don't touch it until 614 * dump is written to disk by userspace tool. This memory 615 * can be released for general use by invalidating fadump. 616 */ 617 fadump_reserve_crash_area(base); 618 619 pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr); 620 pr_debug("Reserve dump area start address: 0x%lx\n", 621 fw_dump.reserve_dump_area_start); 622 } else { 623 /* 624 * Reserve memory at an offset closer to bottom of the RAM to 625 * minimize the impact of memory hot-remove operation. 626 */ 627 base = fadump_locate_reserve_mem(base, size); 628 629 if (!base || (base + size > mem_boundary)) { 630 pr_err("Failed to find memory chunk for reservation!\n"); 631 goto error_out; 632 } 633 fw_dump.reserve_dump_area_start = base; 634 635 /* 636 * Calculate the kernel metadata address and register it with 637 * f/w if the platform supports. 638 */ 639 if (fw_dump.ops->fadump_setup_metadata && 640 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)) 641 goto error_out; 642 643 if (memblock_reserve(base, size)) { 644 pr_err("Failed to reserve memory!\n"); 645 goto error_out; 646 } 647 648 pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n", 649 (size >> 20), base, (memblock_phys_mem_size() >> 20)); 650 651 ret = fadump_cma_init(); 652 } 653 654 return ret; 655 error_out: 656 fw_dump.fadump_enabled = 0; 657 fw_dump.reserve_dump_area_size = 0; 658 return 0; 659 } 660 661 /* Look for fadump= cmdline option. */ 662 static int __init early_fadump_param(char *p) 663 { 664 if (!p) 665 return 1; 666 667 if (strncmp(p, "on", 2) == 0) 668 fw_dump.fadump_enabled = 1; 669 else if (strncmp(p, "off", 3) == 0) 670 fw_dump.fadump_enabled = 0; 671 else if (strncmp(p, "nocma", 5) == 0) { 672 fw_dump.fadump_enabled = 1; 673 fw_dump.nocma = 1; 674 } 675 676 return 0; 677 } 678 early_param("fadump", early_fadump_param); 679 680 /* 681 * Look for fadump_reserve_mem= cmdline option 682 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 683 * the sooner 'crashkernel=' parameter is accustomed to. 684 */ 685 static int __init early_fadump_reserve_mem(char *p) 686 { 687 if (p) 688 fw_dump.reserve_bootvar = memparse(p, &p); 689 return 0; 690 } 691 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 692 693 void crash_fadump(struct pt_regs *regs, const char *str) 694 { 695 unsigned int msecs; 696 struct fadump_crash_info_header *fdh = NULL; 697 int old_cpu, this_cpu; 698 /* Do not include first CPU */ 699 unsigned int ncpus = num_online_cpus() - 1; 700 701 if (!should_fadump_crash()) 702 return; 703 704 /* 705 * old_cpu == -1 means this is the first CPU which has come here, 706 * go ahead and trigger fadump. 707 * 708 * old_cpu != -1 means some other CPU has already on it's way 709 * to trigger fadump, just keep looping here. 710 */ 711 this_cpu = smp_processor_id(); 712 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 713 714 if (old_cpu != -1) { 715 atomic_inc(&cpus_in_fadump); 716 717 /* 718 * We can't loop here indefinitely. Wait as long as fadump 719 * is in force. If we race with fadump un-registration this 720 * loop will break and then we go down to normal panic path 721 * and reboot. If fadump is in force the first crashing 722 * cpu will definitely trigger fadump. 723 */ 724 while (fw_dump.dump_registered) 725 cpu_relax(); 726 return; 727 } 728 729 fdh = __va(fw_dump.fadumphdr_addr); 730 fdh->crashing_cpu = crashing_cpu; 731 crash_save_vmcoreinfo(); 732 733 if (regs) 734 fdh->regs = *regs; 735 else 736 ppc_save_regs(&fdh->regs); 737 738 fdh->cpu_mask = *cpu_online_mask; 739 740 /* 741 * If we came in via system reset, wait a while for the secondary 742 * CPUs to enter. 743 */ 744 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) { 745 msecs = CRASH_TIMEOUT; 746 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0)) 747 mdelay(1); 748 } 749 750 fw_dump.ops->fadump_trigger(fdh, str); 751 } 752 753 u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 754 { 755 struct elf_prstatus prstatus; 756 757 memset(&prstatus, 0, sizeof(prstatus)); 758 /* 759 * FIXME: How do i get PID? Do I really need it? 760 * prstatus.pr_pid = ???? 761 */ 762 elf_core_copy_regs(&prstatus.pr_reg, regs); 763 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 764 &prstatus, sizeof(prstatus)); 765 return buf; 766 } 767 768 void __init fadump_update_elfcore_header(char *bufp) 769 { 770 struct elf_phdr *phdr; 771 772 bufp += sizeof(struct elfhdr); 773 774 /* First note is a place holder for cpu notes info. */ 775 phdr = (struct elf_phdr *)bufp; 776 777 if (phdr->p_type == PT_NOTE) { 778 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr); 779 phdr->p_offset = phdr->p_paddr; 780 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 781 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 782 } 783 return; 784 } 785 786 static void *__init fadump_alloc_buffer(unsigned long size) 787 { 788 unsigned long count, i; 789 struct page *page; 790 void *vaddr; 791 792 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); 793 if (!vaddr) 794 return NULL; 795 796 count = PAGE_ALIGN(size) / PAGE_SIZE; 797 page = virt_to_page(vaddr); 798 for (i = 0; i < count; i++) 799 mark_page_reserved(page + i); 800 return vaddr; 801 } 802 803 static void fadump_free_buffer(unsigned long vaddr, unsigned long size) 804 { 805 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL); 806 } 807 808 s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus) 809 { 810 /* Allocate buffer to hold cpu crash notes. */ 811 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 812 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 813 fw_dump.cpu_notes_buf_vaddr = 814 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size); 815 if (!fw_dump.cpu_notes_buf_vaddr) { 816 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n", 817 fw_dump.cpu_notes_buf_size); 818 return -ENOMEM; 819 } 820 821 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n", 822 fw_dump.cpu_notes_buf_size, 823 fw_dump.cpu_notes_buf_vaddr); 824 return 0; 825 } 826 827 void fadump_free_cpu_notes_buf(void) 828 { 829 if (!fw_dump.cpu_notes_buf_vaddr) 830 return; 831 832 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr, 833 fw_dump.cpu_notes_buf_size); 834 fw_dump.cpu_notes_buf_vaddr = 0; 835 fw_dump.cpu_notes_buf_size = 0; 836 } 837 838 static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info) 839 { 840 if (mrange_info->is_static) { 841 mrange_info->mem_range_cnt = 0; 842 return; 843 } 844 845 kfree(mrange_info->mem_ranges); 846 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0, 847 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ)); 848 } 849 850 /* 851 * Allocate or reallocate mem_ranges array in incremental units 852 * of PAGE_SIZE. 853 */ 854 static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info) 855 { 856 struct fadump_memory_range *new_array; 857 u64 new_size; 858 859 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE; 860 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n", 861 new_size, mrange_info->name); 862 863 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL); 864 if (new_array == NULL) { 865 pr_err("Insufficient memory for setting up %s memory ranges\n", 866 mrange_info->name); 867 fadump_free_mem_ranges(mrange_info); 868 return -ENOMEM; 869 } 870 871 mrange_info->mem_ranges = new_array; 872 mrange_info->mem_ranges_sz = new_size; 873 mrange_info->max_mem_ranges = (new_size / 874 sizeof(struct fadump_memory_range)); 875 return 0; 876 } 877 static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info, 878 u64 base, u64 end) 879 { 880 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges; 881 bool is_adjacent = false; 882 u64 start, size; 883 884 if (base == end) 885 return 0; 886 887 /* 888 * Fold adjacent memory ranges to bring down the memory ranges/ 889 * PT_LOAD segments count. 890 */ 891 if (mrange_info->mem_range_cnt) { 892 start = mem_ranges[mrange_info->mem_range_cnt - 1].base; 893 size = mem_ranges[mrange_info->mem_range_cnt - 1].size; 894 895 /* 896 * Boot memory area needs separate PT_LOAD segment(s) as it 897 * is moved to a different location at the time of crash. 898 * So, fold only if the region is not boot memory area. 899 */ 900 if ((start + size) == base && start >= fw_dump.boot_mem_top) 901 is_adjacent = true; 902 } 903 if (!is_adjacent) { 904 /* resize the array on reaching the limit */ 905 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) { 906 int ret; 907 908 if (mrange_info->is_static) { 909 pr_err("Reached array size limit for %s memory ranges\n", 910 mrange_info->name); 911 return -ENOSPC; 912 } 913 914 ret = fadump_alloc_mem_ranges(mrange_info); 915 if (ret) 916 return ret; 917 918 /* Update to the new resized array */ 919 mem_ranges = mrange_info->mem_ranges; 920 } 921 922 start = base; 923 mem_ranges[mrange_info->mem_range_cnt].base = start; 924 mrange_info->mem_range_cnt++; 925 } 926 927 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start); 928 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 929 mrange_info->name, (mrange_info->mem_range_cnt - 1), 930 start, end - 1, (end - start)); 931 return 0; 932 } 933 934 static int fadump_exclude_reserved_area(u64 start, u64 end) 935 { 936 u64 ra_start, ra_end; 937 int ret = 0; 938 939 ra_start = fw_dump.reserve_dump_area_start; 940 ra_end = ra_start + fw_dump.reserve_dump_area_size; 941 942 if ((ra_start < end) && (ra_end > start)) { 943 if ((start < ra_start) && (end > ra_end)) { 944 ret = fadump_add_mem_range(&crash_mrange_info, 945 start, ra_start); 946 if (ret) 947 return ret; 948 949 ret = fadump_add_mem_range(&crash_mrange_info, 950 ra_end, end); 951 } else if (start < ra_start) { 952 ret = fadump_add_mem_range(&crash_mrange_info, 953 start, ra_start); 954 } else if (ra_end < end) { 955 ret = fadump_add_mem_range(&crash_mrange_info, 956 ra_end, end); 957 } 958 } else 959 ret = fadump_add_mem_range(&crash_mrange_info, start, end); 960 961 return ret; 962 } 963 964 static int fadump_init_elfcore_header(char *bufp) 965 { 966 struct elfhdr *elf; 967 968 elf = (struct elfhdr *) bufp; 969 bufp += sizeof(struct elfhdr); 970 memcpy(elf->e_ident, ELFMAG, SELFMAG); 971 elf->e_ident[EI_CLASS] = ELF_CLASS; 972 elf->e_ident[EI_DATA] = ELF_DATA; 973 elf->e_ident[EI_VERSION] = EV_CURRENT; 974 elf->e_ident[EI_OSABI] = ELF_OSABI; 975 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 976 elf->e_type = ET_CORE; 977 elf->e_machine = ELF_ARCH; 978 elf->e_version = EV_CURRENT; 979 elf->e_entry = 0; 980 elf->e_phoff = sizeof(struct elfhdr); 981 elf->e_shoff = 0; 982 983 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) 984 elf->e_flags = 2; 985 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) 986 elf->e_flags = 1; 987 else 988 elf->e_flags = 0; 989 990 elf->e_ehsize = sizeof(struct elfhdr); 991 elf->e_phentsize = sizeof(struct elf_phdr); 992 elf->e_phnum = 0; 993 elf->e_shentsize = 0; 994 elf->e_shnum = 0; 995 elf->e_shstrndx = 0; 996 997 return 0; 998 } 999 1000 /* 1001 * Traverse through memblock structure and setup crash memory ranges. These 1002 * ranges will be used create PT_LOAD program headers in elfcore header. 1003 */ 1004 static int fadump_setup_crash_memory_ranges(void) 1005 { 1006 u64 i, start, end; 1007 int ret; 1008 1009 pr_debug("Setup crash memory ranges.\n"); 1010 crash_mrange_info.mem_range_cnt = 0; 1011 1012 /* 1013 * Boot memory region(s) registered with firmware are moved to 1014 * different location at the time of crash. Create separate program 1015 * header(s) for this memory chunk(s) with the correct offset. 1016 */ 1017 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 1018 start = fw_dump.boot_mem_addr[i]; 1019 end = start + fw_dump.boot_mem_sz[i]; 1020 ret = fadump_add_mem_range(&crash_mrange_info, start, end); 1021 if (ret) 1022 return ret; 1023 } 1024 1025 for_each_mem_range(i, &start, &end) { 1026 /* 1027 * skip the memory chunk that is already added 1028 * (0 through boot_memory_top). 1029 */ 1030 if (start < fw_dump.boot_mem_top) { 1031 if (end > fw_dump.boot_mem_top) 1032 start = fw_dump.boot_mem_top; 1033 else 1034 continue; 1035 } 1036 1037 /* add this range excluding the reserved dump area. */ 1038 ret = fadump_exclude_reserved_area(start, end); 1039 if (ret) 1040 return ret; 1041 } 1042 1043 return 0; 1044 } 1045 1046 /* 1047 * If the given physical address falls within the boot memory region then 1048 * return the relocated address that points to the dump region reserved 1049 * for saving initial boot memory contents. 1050 */ 1051 static inline unsigned long fadump_relocate(unsigned long paddr) 1052 { 1053 unsigned long raddr, rstart, rend, rlast, hole_size; 1054 int i; 1055 1056 hole_size = 0; 1057 rlast = 0; 1058 raddr = paddr; 1059 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 1060 rstart = fw_dump.boot_mem_addr[i]; 1061 rend = rstart + fw_dump.boot_mem_sz[i]; 1062 hole_size += (rstart - rlast); 1063 1064 if (paddr >= rstart && paddr < rend) { 1065 raddr += fw_dump.boot_mem_dest_addr - hole_size; 1066 break; 1067 } 1068 1069 rlast = rend; 1070 } 1071 1072 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr); 1073 return raddr; 1074 } 1075 1076 static int fadump_create_elfcore_headers(char *bufp) 1077 { 1078 unsigned long long raddr, offset; 1079 struct elf_phdr *phdr; 1080 struct elfhdr *elf; 1081 int i, j; 1082 1083 fadump_init_elfcore_header(bufp); 1084 elf = (struct elfhdr *)bufp; 1085 bufp += sizeof(struct elfhdr); 1086 1087 /* 1088 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1089 * will be populated during second kernel boot after crash. Hence 1090 * this PT_NOTE will always be the first elf note. 1091 * 1092 * NOTE: Any new ELF note addition should be placed after this note. 1093 */ 1094 phdr = (struct elf_phdr *)bufp; 1095 bufp += sizeof(struct elf_phdr); 1096 phdr->p_type = PT_NOTE; 1097 phdr->p_flags = 0; 1098 phdr->p_vaddr = 0; 1099 phdr->p_align = 0; 1100 1101 phdr->p_offset = 0; 1102 phdr->p_paddr = 0; 1103 phdr->p_filesz = 0; 1104 phdr->p_memsz = 0; 1105 1106 (elf->e_phnum)++; 1107 1108 /* setup ELF PT_NOTE for vmcoreinfo */ 1109 phdr = (struct elf_phdr *)bufp; 1110 bufp += sizeof(struct elf_phdr); 1111 phdr->p_type = PT_NOTE; 1112 phdr->p_flags = 0; 1113 phdr->p_vaddr = 0; 1114 phdr->p_align = 0; 1115 1116 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1117 phdr->p_offset = phdr->p_paddr; 1118 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1119 1120 /* Increment number of program headers. */ 1121 (elf->e_phnum)++; 1122 1123 /* setup PT_LOAD sections. */ 1124 j = 0; 1125 offset = 0; 1126 raddr = fw_dump.boot_mem_addr[0]; 1127 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) { 1128 u64 mbase, msize; 1129 1130 mbase = crash_mrange_info.mem_ranges[i].base; 1131 msize = crash_mrange_info.mem_ranges[i].size; 1132 if (!msize) 1133 continue; 1134 1135 phdr = (struct elf_phdr *)bufp; 1136 bufp += sizeof(struct elf_phdr); 1137 phdr->p_type = PT_LOAD; 1138 phdr->p_flags = PF_R|PF_W|PF_X; 1139 phdr->p_offset = mbase; 1140 1141 if (mbase == raddr) { 1142 /* 1143 * The entire real memory region will be moved by 1144 * firmware to the specified destination_address. 1145 * Hence set the correct offset. 1146 */ 1147 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset; 1148 if (j < (fw_dump.boot_mem_regs_cnt - 1)) { 1149 offset += fw_dump.boot_mem_sz[j]; 1150 raddr = fw_dump.boot_mem_addr[++j]; 1151 } 1152 } 1153 1154 phdr->p_paddr = mbase; 1155 phdr->p_vaddr = (unsigned long)__va(mbase); 1156 phdr->p_filesz = msize; 1157 phdr->p_memsz = msize; 1158 phdr->p_align = 0; 1159 1160 /* Increment number of program headers. */ 1161 (elf->e_phnum)++; 1162 } 1163 return 0; 1164 } 1165 1166 static unsigned long init_fadump_header(unsigned long addr) 1167 { 1168 struct fadump_crash_info_header *fdh; 1169 1170 if (!addr) 1171 return 0; 1172 1173 fdh = __va(addr); 1174 addr += sizeof(struct fadump_crash_info_header); 1175 1176 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1177 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1178 fdh->elfcorehdr_addr = addr; 1179 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1180 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN; 1181 /* 1182 * When LPAR is terminated by PYHP, ensure all possible CPUs' 1183 * register data is processed while exporting the vmcore. 1184 */ 1185 fdh->cpu_mask = *cpu_possible_mask; 1186 1187 return addr; 1188 } 1189 1190 static int register_fadump(void) 1191 { 1192 unsigned long addr; 1193 void *vaddr; 1194 int ret; 1195 1196 /* 1197 * If no memory is reserved then we can not register for firmware- 1198 * assisted dump. 1199 */ 1200 if (!fw_dump.reserve_dump_area_size) 1201 return -ENODEV; 1202 1203 ret = fadump_setup_crash_memory_ranges(); 1204 if (ret) 1205 return ret; 1206 1207 addr = fw_dump.fadumphdr_addr; 1208 1209 /* Initialize fadump crash info header. */ 1210 addr = init_fadump_header(addr); 1211 vaddr = __va(addr); 1212 1213 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1214 fadump_create_elfcore_headers(vaddr); 1215 1216 /* register the future kernel dump with firmware. */ 1217 pr_debug("Registering for firmware-assisted kernel dump...\n"); 1218 return fw_dump.ops->fadump_register(&fw_dump); 1219 } 1220 1221 void fadump_cleanup(void) 1222 { 1223 if (!fw_dump.fadump_supported) 1224 return; 1225 1226 /* Invalidate the registration only if dump is active. */ 1227 if (fw_dump.dump_active) { 1228 pr_debug("Invalidating firmware-assisted dump registration\n"); 1229 fw_dump.ops->fadump_invalidate(&fw_dump); 1230 } else if (fw_dump.dump_registered) { 1231 /* Un-register Firmware-assisted dump if it was registered. */ 1232 fw_dump.ops->fadump_unregister(&fw_dump); 1233 fadump_free_mem_ranges(&crash_mrange_info); 1234 } 1235 1236 if (fw_dump.ops->fadump_cleanup) 1237 fw_dump.ops->fadump_cleanup(&fw_dump); 1238 } 1239 1240 static void fadump_free_reserved_memory(unsigned long start_pfn, 1241 unsigned long end_pfn) 1242 { 1243 unsigned long pfn; 1244 unsigned long time_limit = jiffies + HZ; 1245 1246 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1247 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1248 1249 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1250 free_reserved_page(pfn_to_page(pfn)); 1251 1252 if (time_after(jiffies, time_limit)) { 1253 cond_resched(); 1254 time_limit = jiffies + HZ; 1255 } 1256 } 1257 } 1258 1259 /* 1260 * Skip memory holes and free memory that was actually reserved. 1261 */ 1262 static void fadump_release_reserved_area(u64 start, u64 end) 1263 { 1264 unsigned long reg_spfn, reg_epfn; 1265 u64 tstart, tend, spfn, epfn; 1266 int i; 1267 1268 spfn = PHYS_PFN(start); 1269 epfn = PHYS_PFN(end); 1270 1271 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) { 1272 tstart = max_t(u64, spfn, reg_spfn); 1273 tend = min_t(u64, epfn, reg_epfn); 1274 1275 if (tstart < tend) { 1276 fadump_free_reserved_memory(tstart, tend); 1277 1278 if (tend == epfn) 1279 break; 1280 1281 spfn = tend; 1282 } 1283 } 1284 } 1285 1286 /* 1287 * Sort the mem ranges in-place and merge adjacent ranges 1288 * to minimize the memory ranges count. 1289 */ 1290 static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info) 1291 { 1292 struct fadump_memory_range *mem_ranges; 1293 u64 base, size; 1294 int i, j, idx; 1295 1296 if (!reserved_mrange_info.mem_range_cnt) 1297 return; 1298 1299 /* Sort the memory ranges */ 1300 mem_ranges = mrange_info->mem_ranges; 1301 for (i = 0; i < mrange_info->mem_range_cnt; i++) { 1302 idx = i; 1303 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) { 1304 if (mem_ranges[idx].base > mem_ranges[j].base) 1305 idx = j; 1306 } 1307 if (idx != i) 1308 swap(mem_ranges[idx], mem_ranges[i]); 1309 } 1310 1311 /* Merge adjacent reserved ranges */ 1312 idx = 0; 1313 for (i = 1; i < mrange_info->mem_range_cnt; i++) { 1314 base = mem_ranges[i-1].base; 1315 size = mem_ranges[i-1].size; 1316 if (mem_ranges[i].base == (base + size)) 1317 mem_ranges[idx].size += mem_ranges[i].size; 1318 else { 1319 idx++; 1320 if (i == idx) 1321 continue; 1322 1323 mem_ranges[idx] = mem_ranges[i]; 1324 } 1325 } 1326 mrange_info->mem_range_cnt = idx + 1; 1327 } 1328 1329 /* 1330 * Scan reserved-ranges to consider them while reserving/releasing 1331 * memory for FADump. 1332 */ 1333 static void __init early_init_dt_scan_reserved_ranges(unsigned long node) 1334 { 1335 const __be32 *prop; 1336 int len, ret = -1; 1337 unsigned long i; 1338 1339 /* reserved-ranges already scanned */ 1340 if (reserved_mrange_info.mem_range_cnt != 0) 1341 return; 1342 1343 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len); 1344 if (!prop) 1345 return; 1346 1347 /* 1348 * Each reserved range is an (address,size) pair, 2 cells each, 1349 * totalling 4 cells per range. 1350 */ 1351 for (i = 0; i < len / (sizeof(*prop) * 4); i++) { 1352 u64 base, size; 1353 1354 base = of_read_number(prop + (i * 4) + 0, 2); 1355 size = of_read_number(prop + (i * 4) + 2, 2); 1356 1357 if (size) { 1358 ret = fadump_add_mem_range(&reserved_mrange_info, 1359 base, base + size); 1360 if (ret < 0) { 1361 pr_warn("some reserved ranges are ignored!\n"); 1362 break; 1363 } 1364 } 1365 } 1366 1367 /* Compact reserved ranges */ 1368 sort_and_merge_mem_ranges(&reserved_mrange_info); 1369 } 1370 1371 /* 1372 * Release the memory that was reserved during early boot to preserve the 1373 * crash'ed kernel's memory contents except reserved dump area (permanent 1374 * reservation) and reserved ranges used by F/W. The released memory will 1375 * be available for general use. 1376 */ 1377 static void fadump_release_memory(u64 begin, u64 end) 1378 { 1379 u64 ra_start, ra_end, tstart; 1380 int i, ret; 1381 1382 ra_start = fw_dump.reserve_dump_area_start; 1383 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1384 1385 /* 1386 * If reserved ranges array limit is hit, overwrite the last reserved 1387 * memory range with reserved dump area to ensure it is excluded from 1388 * the memory being released (reused for next FADump registration). 1389 */ 1390 if (reserved_mrange_info.mem_range_cnt == 1391 reserved_mrange_info.max_mem_ranges) 1392 reserved_mrange_info.mem_range_cnt--; 1393 1394 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end); 1395 if (ret != 0) 1396 return; 1397 1398 /* Get the reserved ranges list in order first. */ 1399 sort_and_merge_mem_ranges(&reserved_mrange_info); 1400 1401 /* Exclude reserved ranges and release remaining memory */ 1402 tstart = begin; 1403 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) { 1404 ra_start = reserved_mrange_info.mem_ranges[i].base; 1405 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size; 1406 1407 if (tstart >= ra_end) 1408 continue; 1409 1410 if (tstart < ra_start) 1411 fadump_release_reserved_area(tstart, ra_start); 1412 tstart = ra_end; 1413 } 1414 1415 if (tstart < end) 1416 fadump_release_reserved_area(tstart, end); 1417 } 1418 1419 static void fadump_invalidate_release_mem(void) 1420 { 1421 mutex_lock(&fadump_mutex); 1422 if (!fw_dump.dump_active) { 1423 mutex_unlock(&fadump_mutex); 1424 return; 1425 } 1426 1427 fadump_cleanup(); 1428 mutex_unlock(&fadump_mutex); 1429 1430 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM()); 1431 fadump_free_cpu_notes_buf(); 1432 1433 /* 1434 * Setup kernel metadata and initialize the kernel dump 1435 * memory structure for FADump re-registration. 1436 */ 1437 if (fw_dump.ops->fadump_setup_metadata && 1438 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)) 1439 pr_warn("Failed to setup kernel metadata!\n"); 1440 fw_dump.ops->fadump_init_mem_struct(&fw_dump); 1441 } 1442 1443 static ssize_t release_mem_store(struct kobject *kobj, 1444 struct kobj_attribute *attr, 1445 const char *buf, size_t count) 1446 { 1447 int input = -1; 1448 1449 if (!fw_dump.dump_active) 1450 return -EPERM; 1451 1452 if (kstrtoint(buf, 0, &input)) 1453 return -EINVAL; 1454 1455 if (input == 1) { 1456 /* 1457 * Take away the '/proc/vmcore'. We are releasing the dump 1458 * memory, hence it will not be valid anymore. 1459 */ 1460 #ifdef CONFIG_PROC_VMCORE 1461 vmcore_cleanup(); 1462 #endif 1463 fadump_invalidate_release_mem(); 1464 1465 } else 1466 return -EINVAL; 1467 return count; 1468 } 1469 1470 /* Release the reserved memory and disable the FADump */ 1471 static void __init unregister_fadump(void) 1472 { 1473 fadump_cleanup(); 1474 fadump_release_memory(fw_dump.reserve_dump_area_start, 1475 fw_dump.reserve_dump_area_size); 1476 fw_dump.fadump_enabled = 0; 1477 kobject_put(fadump_kobj); 1478 } 1479 1480 static ssize_t enabled_show(struct kobject *kobj, 1481 struct kobj_attribute *attr, 1482 char *buf) 1483 { 1484 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1485 } 1486 1487 static ssize_t mem_reserved_show(struct kobject *kobj, 1488 struct kobj_attribute *attr, 1489 char *buf) 1490 { 1491 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size); 1492 } 1493 1494 static ssize_t registered_show(struct kobject *kobj, 1495 struct kobj_attribute *attr, 1496 char *buf) 1497 { 1498 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1499 } 1500 1501 static ssize_t registered_store(struct kobject *kobj, 1502 struct kobj_attribute *attr, 1503 const char *buf, size_t count) 1504 { 1505 int ret = 0; 1506 int input = -1; 1507 1508 if (!fw_dump.fadump_enabled || fw_dump.dump_active) 1509 return -EPERM; 1510 1511 if (kstrtoint(buf, 0, &input)) 1512 return -EINVAL; 1513 1514 mutex_lock(&fadump_mutex); 1515 1516 switch (input) { 1517 case 0: 1518 if (fw_dump.dump_registered == 0) { 1519 goto unlock_out; 1520 } 1521 1522 /* Un-register Firmware-assisted dump */ 1523 pr_debug("Un-register firmware-assisted dump\n"); 1524 fw_dump.ops->fadump_unregister(&fw_dump); 1525 break; 1526 case 1: 1527 if (fw_dump.dump_registered == 1) { 1528 /* Un-register Firmware-assisted dump */ 1529 fw_dump.ops->fadump_unregister(&fw_dump); 1530 } 1531 /* Register Firmware-assisted dump */ 1532 ret = register_fadump(); 1533 break; 1534 default: 1535 ret = -EINVAL; 1536 break; 1537 } 1538 1539 unlock_out: 1540 mutex_unlock(&fadump_mutex); 1541 return ret < 0 ? ret : count; 1542 } 1543 1544 static int fadump_region_show(struct seq_file *m, void *private) 1545 { 1546 if (!fw_dump.fadump_enabled) 1547 return 0; 1548 1549 mutex_lock(&fadump_mutex); 1550 fw_dump.ops->fadump_region_show(&fw_dump, m); 1551 mutex_unlock(&fadump_mutex); 1552 return 0; 1553 } 1554 1555 static struct kobj_attribute release_attr = __ATTR_WO(release_mem); 1556 static struct kobj_attribute enable_attr = __ATTR_RO(enabled); 1557 static struct kobj_attribute register_attr = __ATTR_RW(registered); 1558 static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved); 1559 1560 static struct attribute *fadump_attrs[] = { 1561 &enable_attr.attr, 1562 ®ister_attr.attr, 1563 &mem_reserved_attr.attr, 1564 NULL, 1565 }; 1566 1567 ATTRIBUTE_GROUPS(fadump); 1568 1569 DEFINE_SHOW_ATTRIBUTE(fadump_region); 1570 1571 static void __init fadump_init_files(void) 1572 { 1573 int rc = 0; 1574 1575 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); 1576 if (!fadump_kobj) { 1577 pr_err("failed to create fadump kobject\n"); 1578 return; 1579 } 1580 1581 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL, 1582 &fadump_region_fops); 1583 1584 if (fw_dump.dump_active) { 1585 rc = sysfs_create_file(fadump_kobj, &release_attr.attr); 1586 if (rc) 1587 pr_err("unable to create release_mem sysfs file (%d)\n", 1588 rc); 1589 } 1590 1591 rc = sysfs_create_groups(fadump_kobj, fadump_groups); 1592 if (rc) { 1593 pr_err("sysfs group creation failed (%d), unregistering FADump", 1594 rc); 1595 unregister_fadump(); 1596 return; 1597 } 1598 1599 /* 1600 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to 1601 * create symlink at old location to maintain backward compatibility. 1602 * 1603 * - fadump_enabled -> fadump/enabled 1604 * - fadump_registered -> fadump/registered 1605 * - fadump_release_mem -> fadump/release_mem 1606 */ 1607 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, 1608 "enabled", "fadump_enabled"); 1609 if (rc) { 1610 pr_err("unable to create fadump_enabled symlink (%d)", rc); 1611 return; 1612 } 1613 1614 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, 1615 "registered", 1616 "fadump_registered"); 1617 if (rc) { 1618 pr_err("unable to create fadump_registered symlink (%d)", rc); 1619 sysfs_remove_link(kernel_kobj, "fadump_enabled"); 1620 return; 1621 } 1622 1623 if (fw_dump.dump_active) { 1624 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, 1625 fadump_kobj, 1626 "release_mem", 1627 "fadump_release_mem"); 1628 if (rc) 1629 pr_err("unable to create fadump_release_mem symlink (%d)", 1630 rc); 1631 } 1632 return; 1633 } 1634 1635 /* 1636 * Prepare for firmware-assisted dump. 1637 */ 1638 int __init setup_fadump(void) 1639 { 1640 if (!fw_dump.fadump_supported) 1641 return 0; 1642 1643 fadump_init_files(); 1644 fadump_show_config(); 1645 1646 if (!fw_dump.fadump_enabled) 1647 return 1; 1648 1649 /* 1650 * If dump data is available then see if it is valid and prepare for 1651 * saving it to the disk. 1652 */ 1653 if (fw_dump.dump_active) { 1654 /* 1655 * if dump process fails then invalidate the registration 1656 * and release memory before proceeding for re-registration. 1657 */ 1658 if (fw_dump.ops->fadump_process(&fw_dump) < 0) 1659 fadump_invalidate_release_mem(); 1660 } 1661 /* Initialize the kernel dump memory structure and register with f/w */ 1662 else if (fw_dump.reserve_dump_area_size) { 1663 fw_dump.ops->fadump_init_mem_struct(&fw_dump); 1664 register_fadump(); 1665 } 1666 1667 /* 1668 * In case of panic, fadump is triggered via ppc_panic_event() 1669 * panic notifier. Setting crash_kexec_post_notifiers to 'true' 1670 * lets panic() function take crash friendly path before panic 1671 * notifiers are invoked. 1672 */ 1673 crash_kexec_post_notifiers = true; 1674 1675 return 1; 1676 } 1677 /* 1678 * Use subsys_initcall_sync() here because there is dependency with 1679 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization 1680 * is done before registering with f/w. 1681 */ 1682 subsys_initcall_sync(setup_fadump); 1683 #else /* !CONFIG_PRESERVE_FA_DUMP */ 1684 1685 /* Scan the Firmware Assisted dump configuration details. */ 1686 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname, 1687 int depth, void *data) 1688 { 1689 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0)) 1690 return 0; 1691 1692 opal_fadump_dt_scan(&fw_dump, node); 1693 return 1; 1694 } 1695 1696 /* 1697 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel, 1698 * preserve crash data. The subsequent memory preserving kernel boot 1699 * is likely to process this crash data. 1700 */ 1701 int __init fadump_reserve_mem(void) 1702 { 1703 if (fw_dump.dump_active) { 1704 /* 1705 * If last boot has crashed then reserve all the memory 1706 * above boot memory to preserve crash data. 1707 */ 1708 pr_info("Preserving crash data for processing in next boot.\n"); 1709 fadump_reserve_crash_area(fw_dump.boot_mem_top); 1710 } else 1711 pr_debug("FADump-aware kernel..\n"); 1712 1713 return 1; 1714 } 1715 #endif /* CONFIG_PRESERVE_FA_DUMP */ 1716 1717 /* Preserve everything above the base address */ 1718 static void __init fadump_reserve_crash_area(u64 base) 1719 { 1720 u64 i, mstart, mend, msize; 1721 1722 for_each_mem_range(i, &mstart, &mend) { 1723 msize = mend - mstart; 1724 1725 if ((mstart + msize) < base) 1726 continue; 1727 1728 if (mstart < base) { 1729 msize -= (base - mstart); 1730 mstart = base; 1731 } 1732 1733 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data", 1734 (msize >> 20), mstart); 1735 memblock_reserve(mstart, msize); 1736 } 1737 } 1738 1739 unsigned long __init arch_reserved_kernel_pages(void) 1740 { 1741 return memblock_reserved_size() / PAGE_SIZE; 1742 } 1743