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 return 0; 658 } 659 660 /* Look for fadump= cmdline option. */ 661 static int __init early_fadump_param(char *p) 662 { 663 if (!p) 664 return 1; 665 666 if (strncmp(p, "on", 2) == 0) 667 fw_dump.fadump_enabled = 1; 668 else if (strncmp(p, "off", 3) == 0) 669 fw_dump.fadump_enabled = 0; 670 else if (strncmp(p, "nocma", 5) == 0) { 671 fw_dump.fadump_enabled = 1; 672 fw_dump.nocma = 1; 673 } 674 675 return 0; 676 } 677 early_param("fadump", early_fadump_param); 678 679 /* 680 * Look for fadump_reserve_mem= cmdline option 681 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 682 * the sooner 'crashkernel=' parameter is accustomed to. 683 */ 684 static int __init early_fadump_reserve_mem(char *p) 685 { 686 if (p) 687 fw_dump.reserve_bootvar = memparse(p, &p); 688 return 0; 689 } 690 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 691 692 void crash_fadump(struct pt_regs *regs, const char *str) 693 { 694 unsigned int msecs; 695 struct fadump_crash_info_header *fdh = NULL; 696 int old_cpu, this_cpu; 697 /* Do not include first CPU */ 698 unsigned int ncpus = num_online_cpus() - 1; 699 700 if (!should_fadump_crash()) 701 return; 702 703 /* 704 * old_cpu == -1 means this is the first CPU which has come here, 705 * go ahead and trigger fadump. 706 * 707 * old_cpu != -1 means some other CPU has already on it's way 708 * to trigger fadump, just keep looping here. 709 */ 710 this_cpu = smp_processor_id(); 711 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 712 713 if (old_cpu != -1) { 714 atomic_inc(&cpus_in_fadump); 715 716 /* 717 * We can't loop here indefinitely. Wait as long as fadump 718 * is in force. If we race with fadump un-registration this 719 * loop will break and then we go down to normal panic path 720 * and reboot. If fadump is in force the first crashing 721 * cpu will definitely trigger fadump. 722 */ 723 while (fw_dump.dump_registered) 724 cpu_relax(); 725 return; 726 } 727 728 fdh = __va(fw_dump.fadumphdr_addr); 729 fdh->crashing_cpu = crashing_cpu; 730 crash_save_vmcoreinfo(); 731 732 if (regs) 733 fdh->regs = *regs; 734 else 735 ppc_save_regs(&fdh->regs); 736 737 fdh->cpu_mask = *cpu_online_mask; 738 739 /* 740 * If we came in via system reset, wait a while for the secondary 741 * CPUs to enter. 742 */ 743 if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) { 744 msecs = CRASH_TIMEOUT; 745 while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0)) 746 mdelay(1); 747 } 748 749 fw_dump.ops->fadump_trigger(fdh, str); 750 } 751 752 u32 *__init fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 753 { 754 struct elf_prstatus prstatus; 755 756 memset(&prstatus, 0, sizeof(prstatus)); 757 /* 758 * FIXME: How do i get PID? Do I really need it? 759 * prstatus.pr_pid = ???? 760 */ 761 elf_core_copy_regs(&prstatus.pr_reg, regs); 762 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 763 &prstatus, sizeof(prstatus)); 764 return buf; 765 } 766 767 void __init fadump_update_elfcore_header(char *bufp) 768 { 769 struct elf_phdr *phdr; 770 771 bufp += sizeof(struct elfhdr); 772 773 /* First note is a place holder for cpu notes info. */ 774 phdr = (struct elf_phdr *)bufp; 775 776 if (phdr->p_type == PT_NOTE) { 777 phdr->p_paddr = __pa(fw_dump.cpu_notes_buf_vaddr); 778 phdr->p_offset = phdr->p_paddr; 779 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 780 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 781 } 782 return; 783 } 784 785 static void *__init fadump_alloc_buffer(unsigned long size) 786 { 787 unsigned long count, i; 788 struct page *page; 789 void *vaddr; 790 791 vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); 792 if (!vaddr) 793 return NULL; 794 795 count = PAGE_ALIGN(size) / PAGE_SIZE; 796 page = virt_to_page(vaddr); 797 for (i = 0; i < count; i++) 798 mark_page_reserved(page + i); 799 return vaddr; 800 } 801 802 static void fadump_free_buffer(unsigned long vaddr, unsigned long size) 803 { 804 free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL); 805 } 806 807 s32 __init fadump_setup_cpu_notes_buf(u32 num_cpus) 808 { 809 /* Allocate buffer to hold cpu crash notes. */ 810 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 811 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 812 fw_dump.cpu_notes_buf_vaddr = 813 (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size); 814 if (!fw_dump.cpu_notes_buf_vaddr) { 815 pr_err("Failed to allocate %ld bytes for CPU notes buffer\n", 816 fw_dump.cpu_notes_buf_size); 817 return -ENOMEM; 818 } 819 820 pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n", 821 fw_dump.cpu_notes_buf_size, 822 fw_dump.cpu_notes_buf_vaddr); 823 return 0; 824 } 825 826 void fadump_free_cpu_notes_buf(void) 827 { 828 if (!fw_dump.cpu_notes_buf_vaddr) 829 return; 830 831 fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr, 832 fw_dump.cpu_notes_buf_size); 833 fw_dump.cpu_notes_buf_vaddr = 0; 834 fw_dump.cpu_notes_buf_size = 0; 835 } 836 837 static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info) 838 { 839 if (mrange_info->is_static) { 840 mrange_info->mem_range_cnt = 0; 841 return; 842 } 843 844 kfree(mrange_info->mem_ranges); 845 memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0, 846 (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ)); 847 } 848 849 /* 850 * Allocate or reallocate mem_ranges array in incremental units 851 * of PAGE_SIZE. 852 */ 853 static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info) 854 { 855 struct fadump_memory_range *new_array; 856 u64 new_size; 857 858 new_size = mrange_info->mem_ranges_sz + PAGE_SIZE; 859 pr_debug("Allocating %llu bytes of memory for %s memory ranges\n", 860 new_size, mrange_info->name); 861 862 new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL); 863 if (new_array == NULL) { 864 pr_err("Insufficient memory for setting up %s memory ranges\n", 865 mrange_info->name); 866 fadump_free_mem_ranges(mrange_info); 867 return -ENOMEM; 868 } 869 870 mrange_info->mem_ranges = new_array; 871 mrange_info->mem_ranges_sz = new_size; 872 mrange_info->max_mem_ranges = (new_size / 873 sizeof(struct fadump_memory_range)); 874 return 0; 875 } 876 static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info, 877 u64 base, u64 end) 878 { 879 struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges; 880 bool is_adjacent = false; 881 u64 start, size; 882 883 if (base == end) 884 return 0; 885 886 /* 887 * Fold adjacent memory ranges to bring down the memory ranges/ 888 * PT_LOAD segments count. 889 */ 890 if (mrange_info->mem_range_cnt) { 891 start = mem_ranges[mrange_info->mem_range_cnt - 1].base; 892 size = mem_ranges[mrange_info->mem_range_cnt - 1].size; 893 894 /* 895 * Boot memory area needs separate PT_LOAD segment(s) as it 896 * is moved to a different location at the time of crash. 897 * So, fold only if the region is not boot memory area. 898 */ 899 if ((start + size) == base && start >= fw_dump.boot_mem_top) 900 is_adjacent = true; 901 } 902 if (!is_adjacent) { 903 /* resize the array on reaching the limit */ 904 if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) { 905 int ret; 906 907 if (mrange_info->is_static) { 908 pr_err("Reached array size limit for %s memory ranges\n", 909 mrange_info->name); 910 return -ENOSPC; 911 } 912 913 ret = fadump_alloc_mem_ranges(mrange_info); 914 if (ret) 915 return ret; 916 917 /* Update to the new resized array */ 918 mem_ranges = mrange_info->mem_ranges; 919 } 920 921 start = base; 922 mem_ranges[mrange_info->mem_range_cnt].base = start; 923 mrange_info->mem_range_cnt++; 924 } 925 926 mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start); 927 pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 928 mrange_info->name, (mrange_info->mem_range_cnt - 1), 929 start, end - 1, (end - start)); 930 return 0; 931 } 932 933 static int fadump_exclude_reserved_area(u64 start, u64 end) 934 { 935 u64 ra_start, ra_end; 936 int ret = 0; 937 938 ra_start = fw_dump.reserve_dump_area_start; 939 ra_end = ra_start + fw_dump.reserve_dump_area_size; 940 941 if ((ra_start < end) && (ra_end > start)) { 942 if ((start < ra_start) && (end > ra_end)) { 943 ret = fadump_add_mem_range(&crash_mrange_info, 944 start, ra_start); 945 if (ret) 946 return ret; 947 948 ret = fadump_add_mem_range(&crash_mrange_info, 949 ra_end, end); 950 } else if (start < ra_start) { 951 ret = fadump_add_mem_range(&crash_mrange_info, 952 start, ra_start); 953 } else if (ra_end < end) { 954 ret = fadump_add_mem_range(&crash_mrange_info, 955 ra_end, end); 956 } 957 } else 958 ret = fadump_add_mem_range(&crash_mrange_info, start, end); 959 960 return ret; 961 } 962 963 static int fadump_init_elfcore_header(char *bufp) 964 { 965 struct elfhdr *elf; 966 967 elf = (struct elfhdr *) bufp; 968 bufp += sizeof(struct elfhdr); 969 memcpy(elf->e_ident, ELFMAG, SELFMAG); 970 elf->e_ident[EI_CLASS] = ELF_CLASS; 971 elf->e_ident[EI_DATA] = ELF_DATA; 972 elf->e_ident[EI_VERSION] = EV_CURRENT; 973 elf->e_ident[EI_OSABI] = ELF_OSABI; 974 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 975 elf->e_type = ET_CORE; 976 elf->e_machine = ELF_ARCH; 977 elf->e_version = EV_CURRENT; 978 elf->e_entry = 0; 979 elf->e_phoff = sizeof(struct elfhdr); 980 elf->e_shoff = 0; 981 982 if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) 983 elf->e_flags = 2; 984 else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) 985 elf->e_flags = 1; 986 else 987 elf->e_flags = 0; 988 989 elf->e_ehsize = sizeof(struct elfhdr); 990 elf->e_phentsize = sizeof(struct elf_phdr); 991 elf->e_phnum = 0; 992 elf->e_shentsize = 0; 993 elf->e_shnum = 0; 994 elf->e_shstrndx = 0; 995 996 return 0; 997 } 998 999 /* 1000 * Traverse through memblock structure and setup crash memory ranges. These 1001 * ranges will be used create PT_LOAD program headers in elfcore header. 1002 */ 1003 static int fadump_setup_crash_memory_ranges(void) 1004 { 1005 u64 i, start, end; 1006 int ret; 1007 1008 pr_debug("Setup crash memory ranges.\n"); 1009 crash_mrange_info.mem_range_cnt = 0; 1010 1011 /* 1012 * Boot memory region(s) registered with firmware are moved to 1013 * different location at the time of crash. Create separate program 1014 * header(s) for this memory chunk(s) with the correct offset. 1015 */ 1016 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 1017 start = fw_dump.boot_mem_addr[i]; 1018 end = start + fw_dump.boot_mem_sz[i]; 1019 ret = fadump_add_mem_range(&crash_mrange_info, start, end); 1020 if (ret) 1021 return ret; 1022 } 1023 1024 for_each_mem_range(i, &start, &end) { 1025 /* 1026 * skip the memory chunk that is already added 1027 * (0 through boot_memory_top). 1028 */ 1029 if (start < fw_dump.boot_mem_top) { 1030 if (end > fw_dump.boot_mem_top) 1031 start = fw_dump.boot_mem_top; 1032 else 1033 continue; 1034 } 1035 1036 /* add this range excluding the reserved dump area. */ 1037 ret = fadump_exclude_reserved_area(start, end); 1038 if (ret) 1039 return ret; 1040 } 1041 1042 return 0; 1043 } 1044 1045 /* 1046 * If the given physical address falls within the boot memory region then 1047 * return the relocated address that points to the dump region reserved 1048 * for saving initial boot memory contents. 1049 */ 1050 static inline unsigned long fadump_relocate(unsigned long paddr) 1051 { 1052 unsigned long raddr, rstart, rend, rlast, hole_size; 1053 int i; 1054 1055 hole_size = 0; 1056 rlast = 0; 1057 raddr = paddr; 1058 for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { 1059 rstart = fw_dump.boot_mem_addr[i]; 1060 rend = rstart + fw_dump.boot_mem_sz[i]; 1061 hole_size += (rstart - rlast); 1062 1063 if (paddr >= rstart && paddr < rend) { 1064 raddr += fw_dump.boot_mem_dest_addr - hole_size; 1065 break; 1066 } 1067 1068 rlast = rend; 1069 } 1070 1071 pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr); 1072 return raddr; 1073 } 1074 1075 static int fadump_create_elfcore_headers(char *bufp) 1076 { 1077 unsigned long long raddr, offset; 1078 struct elf_phdr *phdr; 1079 struct elfhdr *elf; 1080 int i, j; 1081 1082 fadump_init_elfcore_header(bufp); 1083 elf = (struct elfhdr *)bufp; 1084 bufp += sizeof(struct elfhdr); 1085 1086 /* 1087 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1088 * will be populated during second kernel boot after crash. Hence 1089 * this PT_NOTE will always be the first elf note. 1090 * 1091 * NOTE: Any new ELF note addition should be placed after this note. 1092 */ 1093 phdr = (struct elf_phdr *)bufp; 1094 bufp += sizeof(struct elf_phdr); 1095 phdr->p_type = PT_NOTE; 1096 phdr->p_flags = 0; 1097 phdr->p_vaddr = 0; 1098 phdr->p_align = 0; 1099 1100 phdr->p_offset = 0; 1101 phdr->p_paddr = 0; 1102 phdr->p_filesz = 0; 1103 phdr->p_memsz = 0; 1104 1105 (elf->e_phnum)++; 1106 1107 /* setup ELF PT_NOTE for vmcoreinfo */ 1108 phdr = (struct elf_phdr *)bufp; 1109 bufp += sizeof(struct elf_phdr); 1110 phdr->p_type = PT_NOTE; 1111 phdr->p_flags = 0; 1112 phdr->p_vaddr = 0; 1113 phdr->p_align = 0; 1114 1115 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1116 phdr->p_offset = phdr->p_paddr; 1117 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1118 1119 /* Increment number of program headers. */ 1120 (elf->e_phnum)++; 1121 1122 /* setup PT_LOAD sections. */ 1123 j = 0; 1124 offset = 0; 1125 raddr = fw_dump.boot_mem_addr[0]; 1126 for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) { 1127 u64 mbase, msize; 1128 1129 mbase = crash_mrange_info.mem_ranges[i].base; 1130 msize = crash_mrange_info.mem_ranges[i].size; 1131 if (!msize) 1132 continue; 1133 1134 phdr = (struct elf_phdr *)bufp; 1135 bufp += sizeof(struct elf_phdr); 1136 phdr->p_type = PT_LOAD; 1137 phdr->p_flags = PF_R|PF_W|PF_X; 1138 phdr->p_offset = mbase; 1139 1140 if (mbase == raddr) { 1141 /* 1142 * The entire real memory region will be moved by 1143 * firmware to the specified destination_address. 1144 * Hence set the correct offset. 1145 */ 1146 phdr->p_offset = fw_dump.boot_mem_dest_addr + offset; 1147 if (j < (fw_dump.boot_mem_regs_cnt - 1)) { 1148 offset += fw_dump.boot_mem_sz[j]; 1149 raddr = fw_dump.boot_mem_addr[++j]; 1150 } 1151 } 1152 1153 phdr->p_paddr = mbase; 1154 phdr->p_vaddr = (unsigned long)__va(mbase); 1155 phdr->p_filesz = msize; 1156 phdr->p_memsz = msize; 1157 phdr->p_align = 0; 1158 1159 /* Increment number of program headers. */ 1160 (elf->e_phnum)++; 1161 } 1162 return 0; 1163 } 1164 1165 static unsigned long init_fadump_header(unsigned long addr) 1166 { 1167 struct fadump_crash_info_header *fdh; 1168 1169 if (!addr) 1170 return 0; 1171 1172 fdh = __va(addr); 1173 addr += sizeof(struct fadump_crash_info_header); 1174 1175 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1176 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1177 fdh->elfcorehdr_addr = addr; 1178 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1179 fdh->crashing_cpu = FADUMP_CPU_UNKNOWN; 1180 /* 1181 * When LPAR is terminated by PYHP, ensure all possible CPUs' 1182 * register data is processed while exporting the vmcore. 1183 */ 1184 fdh->cpu_mask = *cpu_possible_mask; 1185 1186 return addr; 1187 } 1188 1189 static int register_fadump(void) 1190 { 1191 unsigned long addr; 1192 void *vaddr; 1193 int ret; 1194 1195 /* 1196 * If no memory is reserved then we can not register for firmware- 1197 * assisted dump. 1198 */ 1199 if (!fw_dump.reserve_dump_area_size) 1200 return -ENODEV; 1201 1202 ret = fadump_setup_crash_memory_ranges(); 1203 if (ret) 1204 return ret; 1205 1206 addr = fw_dump.fadumphdr_addr; 1207 1208 /* Initialize fadump crash info header. */ 1209 addr = init_fadump_header(addr); 1210 vaddr = __va(addr); 1211 1212 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1213 fadump_create_elfcore_headers(vaddr); 1214 1215 /* register the future kernel dump with firmware. */ 1216 pr_debug("Registering for firmware-assisted kernel dump...\n"); 1217 return fw_dump.ops->fadump_register(&fw_dump); 1218 } 1219 1220 void fadump_cleanup(void) 1221 { 1222 if (!fw_dump.fadump_supported) 1223 return; 1224 1225 /* Invalidate the registration only if dump is active. */ 1226 if (fw_dump.dump_active) { 1227 pr_debug("Invalidating firmware-assisted dump registration\n"); 1228 fw_dump.ops->fadump_invalidate(&fw_dump); 1229 } else if (fw_dump.dump_registered) { 1230 /* Un-register Firmware-assisted dump if it was registered. */ 1231 fw_dump.ops->fadump_unregister(&fw_dump); 1232 fadump_free_mem_ranges(&crash_mrange_info); 1233 } 1234 1235 if (fw_dump.ops->fadump_cleanup) 1236 fw_dump.ops->fadump_cleanup(&fw_dump); 1237 } 1238 1239 static void fadump_free_reserved_memory(unsigned long start_pfn, 1240 unsigned long end_pfn) 1241 { 1242 unsigned long pfn; 1243 unsigned long time_limit = jiffies + HZ; 1244 1245 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1246 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1247 1248 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1249 free_reserved_page(pfn_to_page(pfn)); 1250 1251 if (time_after(jiffies, time_limit)) { 1252 cond_resched(); 1253 time_limit = jiffies + HZ; 1254 } 1255 } 1256 } 1257 1258 /* 1259 * Skip memory holes and free memory that was actually reserved. 1260 */ 1261 static void fadump_release_reserved_area(u64 start, u64 end) 1262 { 1263 unsigned long reg_spfn, reg_epfn; 1264 u64 tstart, tend, spfn, epfn; 1265 int i; 1266 1267 spfn = PHYS_PFN(start); 1268 epfn = PHYS_PFN(end); 1269 1270 for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) { 1271 tstart = max_t(u64, spfn, reg_spfn); 1272 tend = min_t(u64, epfn, reg_epfn); 1273 1274 if (tstart < tend) { 1275 fadump_free_reserved_memory(tstart, tend); 1276 1277 if (tend == epfn) 1278 break; 1279 1280 spfn = tend; 1281 } 1282 } 1283 } 1284 1285 /* 1286 * Sort the mem ranges in-place and merge adjacent ranges 1287 * to minimize the memory ranges count. 1288 */ 1289 static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info) 1290 { 1291 struct fadump_memory_range *mem_ranges; 1292 u64 base, size; 1293 int i, j, idx; 1294 1295 if (!reserved_mrange_info.mem_range_cnt) 1296 return; 1297 1298 /* Sort the memory ranges */ 1299 mem_ranges = mrange_info->mem_ranges; 1300 for (i = 0; i < mrange_info->mem_range_cnt; i++) { 1301 idx = i; 1302 for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) { 1303 if (mem_ranges[idx].base > mem_ranges[j].base) 1304 idx = j; 1305 } 1306 if (idx != i) 1307 swap(mem_ranges[idx], mem_ranges[i]); 1308 } 1309 1310 /* Merge adjacent reserved ranges */ 1311 idx = 0; 1312 for (i = 1; i < mrange_info->mem_range_cnt; i++) { 1313 base = mem_ranges[i-1].base; 1314 size = mem_ranges[i-1].size; 1315 if (mem_ranges[i].base == (base + size)) 1316 mem_ranges[idx].size += mem_ranges[i].size; 1317 else { 1318 idx++; 1319 if (i == idx) 1320 continue; 1321 1322 mem_ranges[idx] = mem_ranges[i]; 1323 } 1324 } 1325 mrange_info->mem_range_cnt = idx + 1; 1326 } 1327 1328 /* 1329 * Scan reserved-ranges to consider them while reserving/releasing 1330 * memory for FADump. 1331 */ 1332 static void __init early_init_dt_scan_reserved_ranges(unsigned long node) 1333 { 1334 const __be32 *prop; 1335 int len, ret = -1; 1336 unsigned long i; 1337 1338 /* reserved-ranges already scanned */ 1339 if (reserved_mrange_info.mem_range_cnt != 0) 1340 return; 1341 1342 prop = of_get_flat_dt_prop(node, "reserved-ranges", &len); 1343 if (!prop) 1344 return; 1345 1346 /* 1347 * Each reserved range is an (address,size) pair, 2 cells each, 1348 * totalling 4 cells per range. 1349 */ 1350 for (i = 0; i < len / (sizeof(*prop) * 4); i++) { 1351 u64 base, size; 1352 1353 base = of_read_number(prop + (i * 4) + 0, 2); 1354 size = of_read_number(prop + (i * 4) + 2, 2); 1355 1356 if (size) { 1357 ret = fadump_add_mem_range(&reserved_mrange_info, 1358 base, base + size); 1359 if (ret < 0) { 1360 pr_warn("some reserved ranges are ignored!\n"); 1361 break; 1362 } 1363 } 1364 } 1365 1366 /* Compact reserved ranges */ 1367 sort_and_merge_mem_ranges(&reserved_mrange_info); 1368 } 1369 1370 /* 1371 * Release the memory that was reserved during early boot to preserve the 1372 * crash'ed kernel's memory contents except reserved dump area (permanent 1373 * reservation) and reserved ranges used by F/W. The released memory will 1374 * be available for general use. 1375 */ 1376 static void fadump_release_memory(u64 begin, u64 end) 1377 { 1378 u64 ra_start, ra_end, tstart; 1379 int i, ret; 1380 1381 ra_start = fw_dump.reserve_dump_area_start; 1382 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1383 1384 /* 1385 * If reserved ranges array limit is hit, overwrite the last reserved 1386 * memory range with reserved dump area to ensure it is excluded from 1387 * the memory being released (reused for next FADump registration). 1388 */ 1389 if (reserved_mrange_info.mem_range_cnt == 1390 reserved_mrange_info.max_mem_ranges) 1391 reserved_mrange_info.mem_range_cnt--; 1392 1393 ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end); 1394 if (ret != 0) 1395 return; 1396 1397 /* Get the reserved ranges list in order first. */ 1398 sort_and_merge_mem_ranges(&reserved_mrange_info); 1399 1400 /* Exclude reserved ranges and release remaining memory */ 1401 tstart = begin; 1402 for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) { 1403 ra_start = reserved_mrange_info.mem_ranges[i].base; 1404 ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size; 1405 1406 if (tstart >= ra_end) 1407 continue; 1408 1409 if (tstart < ra_start) 1410 fadump_release_reserved_area(tstart, ra_start); 1411 tstart = ra_end; 1412 } 1413 1414 if (tstart < end) 1415 fadump_release_reserved_area(tstart, end); 1416 } 1417 1418 static void fadump_invalidate_release_mem(void) 1419 { 1420 mutex_lock(&fadump_mutex); 1421 if (!fw_dump.dump_active) { 1422 mutex_unlock(&fadump_mutex); 1423 return; 1424 } 1425 1426 fadump_cleanup(); 1427 mutex_unlock(&fadump_mutex); 1428 1429 fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM()); 1430 fadump_free_cpu_notes_buf(); 1431 1432 /* 1433 * Setup kernel metadata and initialize the kernel dump 1434 * memory structure for FADump re-registration. 1435 */ 1436 if (fw_dump.ops->fadump_setup_metadata && 1437 (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)) 1438 pr_warn("Failed to setup kernel metadata!\n"); 1439 fw_dump.ops->fadump_init_mem_struct(&fw_dump); 1440 } 1441 1442 static ssize_t release_mem_store(struct kobject *kobj, 1443 struct kobj_attribute *attr, 1444 const char *buf, size_t count) 1445 { 1446 int input = -1; 1447 1448 if (!fw_dump.dump_active) 1449 return -EPERM; 1450 1451 if (kstrtoint(buf, 0, &input)) 1452 return -EINVAL; 1453 1454 if (input == 1) { 1455 /* 1456 * Take away the '/proc/vmcore'. We are releasing the dump 1457 * memory, hence it will not be valid anymore. 1458 */ 1459 #ifdef CONFIG_PROC_VMCORE 1460 vmcore_cleanup(); 1461 #endif 1462 fadump_invalidate_release_mem(); 1463 1464 } else 1465 return -EINVAL; 1466 return count; 1467 } 1468 1469 /* Release the reserved memory and disable the FADump */ 1470 static void __init unregister_fadump(void) 1471 { 1472 fadump_cleanup(); 1473 fadump_release_memory(fw_dump.reserve_dump_area_start, 1474 fw_dump.reserve_dump_area_size); 1475 fw_dump.fadump_enabled = 0; 1476 kobject_put(fadump_kobj); 1477 } 1478 1479 static ssize_t enabled_show(struct kobject *kobj, 1480 struct kobj_attribute *attr, 1481 char *buf) 1482 { 1483 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1484 } 1485 1486 static ssize_t mem_reserved_show(struct kobject *kobj, 1487 struct kobj_attribute *attr, 1488 char *buf) 1489 { 1490 return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size); 1491 } 1492 1493 static ssize_t registered_show(struct kobject *kobj, 1494 struct kobj_attribute *attr, 1495 char *buf) 1496 { 1497 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1498 } 1499 1500 static ssize_t registered_store(struct kobject *kobj, 1501 struct kobj_attribute *attr, 1502 const char *buf, size_t count) 1503 { 1504 int ret = 0; 1505 int input = -1; 1506 1507 if (!fw_dump.fadump_enabled || fw_dump.dump_active) 1508 return -EPERM; 1509 1510 if (kstrtoint(buf, 0, &input)) 1511 return -EINVAL; 1512 1513 mutex_lock(&fadump_mutex); 1514 1515 switch (input) { 1516 case 0: 1517 if (fw_dump.dump_registered == 0) { 1518 goto unlock_out; 1519 } 1520 1521 /* Un-register Firmware-assisted dump */ 1522 pr_debug("Un-register firmware-assisted dump\n"); 1523 fw_dump.ops->fadump_unregister(&fw_dump); 1524 break; 1525 case 1: 1526 if (fw_dump.dump_registered == 1) { 1527 /* Un-register Firmware-assisted dump */ 1528 fw_dump.ops->fadump_unregister(&fw_dump); 1529 } 1530 /* Register Firmware-assisted dump */ 1531 ret = register_fadump(); 1532 break; 1533 default: 1534 ret = -EINVAL; 1535 break; 1536 } 1537 1538 unlock_out: 1539 mutex_unlock(&fadump_mutex); 1540 return ret < 0 ? ret : count; 1541 } 1542 1543 static int fadump_region_show(struct seq_file *m, void *private) 1544 { 1545 if (!fw_dump.fadump_enabled) 1546 return 0; 1547 1548 mutex_lock(&fadump_mutex); 1549 fw_dump.ops->fadump_region_show(&fw_dump, m); 1550 mutex_unlock(&fadump_mutex); 1551 return 0; 1552 } 1553 1554 static struct kobj_attribute release_attr = __ATTR_WO(release_mem); 1555 static struct kobj_attribute enable_attr = __ATTR_RO(enabled); 1556 static struct kobj_attribute register_attr = __ATTR_RW(registered); 1557 static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved); 1558 1559 static struct attribute *fadump_attrs[] = { 1560 &enable_attr.attr, 1561 ®ister_attr.attr, 1562 &mem_reserved_attr.attr, 1563 NULL, 1564 }; 1565 1566 ATTRIBUTE_GROUPS(fadump); 1567 1568 DEFINE_SHOW_ATTRIBUTE(fadump_region); 1569 1570 static void __init fadump_init_files(void) 1571 { 1572 int rc = 0; 1573 1574 fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); 1575 if (!fadump_kobj) { 1576 pr_err("failed to create fadump kobject\n"); 1577 return; 1578 } 1579 1580 debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL, 1581 &fadump_region_fops); 1582 1583 if (fw_dump.dump_active) { 1584 rc = sysfs_create_file(fadump_kobj, &release_attr.attr); 1585 if (rc) 1586 pr_err("unable to create release_mem sysfs file (%d)\n", 1587 rc); 1588 } 1589 1590 rc = sysfs_create_groups(fadump_kobj, fadump_groups); 1591 if (rc) { 1592 pr_err("sysfs group creation failed (%d), unregistering FADump", 1593 rc); 1594 unregister_fadump(); 1595 return; 1596 } 1597 1598 /* 1599 * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to 1600 * create symlink at old location to maintain backward compatibility. 1601 * 1602 * - fadump_enabled -> fadump/enabled 1603 * - fadump_registered -> fadump/registered 1604 * - fadump_release_mem -> fadump/release_mem 1605 */ 1606 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, 1607 "enabled", "fadump_enabled"); 1608 if (rc) { 1609 pr_err("unable to create fadump_enabled symlink (%d)", rc); 1610 return; 1611 } 1612 1613 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, 1614 "registered", 1615 "fadump_registered"); 1616 if (rc) { 1617 pr_err("unable to create fadump_registered symlink (%d)", rc); 1618 sysfs_remove_link(kernel_kobj, "fadump_enabled"); 1619 return; 1620 } 1621 1622 if (fw_dump.dump_active) { 1623 rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, 1624 fadump_kobj, 1625 "release_mem", 1626 "fadump_release_mem"); 1627 if (rc) 1628 pr_err("unable to create fadump_release_mem symlink (%d)", 1629 rc); 1630 } 1631 return; 1632 } 1633 1634 /* 1635 * Prepare for firmware-assisted dump. 1636 */ 1637 int __init setup_fadump(void) 1638 { 1639 if (!fw_dump.fadump_supported) 1640 return 0; 1641 1642 fadump_init_files(); 1643 fadump_show_config(); 1644 1645 if (!fw_dump.fadump_enabled) 1646 return 1; 1647 1648 /* 1649 * If dump data is available then see if it is valid and prepare for 1650 * saving it to the disk. 1651 */ 1652 if (fw_dump.dump_active) { 1653 /* 1654 * if dump process fails then invalidate the registration 1655 * and release memory before proceeding for re-registration. 1656 */ 1657 if (fw_dump.ops->fadump_process(&fw_dump) < 0) 1658 fadump_invalidate_release_mem(); 1659 } 1660 /* Initialize the kernel dump memory structure and register with f/w */ 1661 else if (fw_dump.reserve_dump_area_size) { 1662 fw_dump.ops->fadump_init_mem_struct(&fw_dump); 1663 register_fadump(); 1664 } 1665 1666 /* 1667 * In case of panic, fadump is triggered via ppc_panic_event() 1668 * panic notifier. Setting crash_kexec_post_notifiers to 'true' 1669 * lets panic() function take crash friendly path before panic 1670 * notifiers are invoked. 1671 */ 1672 crash_kexec_post_notifiers = true; 1673 1674 return 1; 1675 } 1676 /* 1677 * Use subsys_initcall_sync() here because there is dependency with 1678 * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization 1679 * is done before registering with f/w. 1680 */ 1681 subsys_initcall_sync(setup_fadump); 1682 #else /* !CONFIG_PRESERVE_FA_DUMP */ 1683 1684 /* Scan the Firmware Assisted dump configuration details. */ 1685 int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname, 1686 int depth, void *data) 1687 { 1688 if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0)) 1689 return 0; 1690 1691 opal_fadump_dt_scan(&fw_dump, node); 1692 return 1; 1693 } 1694 1695 /* 1696 * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel, 1697 * preserve crash data. The subsequent memory preserving kernel boot 1698 * is likely to process this crash data. 1699 */ 1700 int __init fadump_reserve_mem(void) 1701 { 1702 if (fw_dump.dump_active) { 1703 /* 1704 * If last boot has crashed then reserve all the memory 1705 * above boot memory to preserve crash data. 1706 */ 1707 pr_info("Preserving crash data for processing in next boot.\n"); 1708 fadump_reserve_crash_area(fw_dump.boot_mem_top); 1709 } else 1710 pr_debug("FADump-aware kernel..\n"); 1711 1712 return 1; 1713 } 1714 #endif /* CONFIG_PRESERVE_FA_DUMP */ 1715 1716 /* Preserve everything above the base address */ 1717 static void __init fadump_reserve_crash_area(u64 base) 1718 { 1719 u64 i, mstart, mend, msize; 1720 1721 for_each_mem_range(i, &mstart, &mend) { 1722 msize = mend - mstart; 1723 1724 if ((mstart + msize) < base) 1725 continue; 1726 1727 if (mstart < base) { 1728 msize -= (base - mstart); 1729 mstart = base; 1730 } 1731 1732 pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data", 1733 (msize >> 20), mstart); 1734 memblock_reserve(mstart, msize); 1735 } 1736 } 1737 1738 unsigned long __init arch_reserved_kernel_pages(void) 1739 { 1740 return memblock_reserved_size() / PAGE_SIZE; 1741 } 1742