1 /* 2 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash 3 * dump with assistance from firmware. This approach does not use kexec, 4 * instead firmware assists in booting the kdump kernel while preserving 5 * memory contents. The most of the code implementation has been adapted 6 * from phyp assisted dump implementation written by Linas Vepstas and 7 * Manish Ahuja 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 22 * 23 * Copyright 2011 IBM Corporation 24 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 25 */ 26 27 #undef DEBUG 28 #define pr_fmt(fmt) "fadump: " fmt 29 30 #include <linux/string.h> 31 #include <linux/memblock.h> 32 #include <linux/delay.h> 33 #include <linux/seq_file.h> 34 #include <linux/crash_dump.h> 35 #include <linux/kobject.h> 36 #include <linux/sysfs.h> 37 #include <linux/slab.h> 38 #include <linux/cma.h> 39 40 #include <asm/debugfs.h> 41 #include <asm/page.h> 42 #include <asm/prom.h> 43 #include <asm/rtas.h> 44 #include <asm/fadump.h> 45 #include <asm/setup.h> 46 47 static struct fw_dump fw_dump; 48 static struct fadump_mem_struct fdm; 49 static const struct fadump_mem_struct *fdm_active; 50 #ifdef CONFIG_CMA 51 static struct cma *fadump_cma; 52 #endif 53 54 static DEFINE_MUTEX(fadump_mutex); 55 struct fad_crash_memory_ranges *crash_memory_ranges; 56 int crash_memory_ranges_size; 57 int crash_mem_ranges; 58 int max_crash_mem_ranges; 59 60 #ifdef CONFIG_CMA 61 /* 62 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory 63 * 64 * This function initializes CMA area from fadump reserved memory. 65 * The total size of fadump reserved memory covers for boot memory size 66 * + cpu data size + hpte size and metadata. 67 * Initialize only the area equivalent to boot memory size for CMA use. 68 * The reamining portion of fadump reserved memory will be not given 69 * to CMA and pages for thoes will stay reserved. boot memory size is 70 * aligned per CMA requirement to satisy cma_init_reserved_mem() call. 71 * But for some reason even if it fails we still have the memory reservation 72 * with us and we can still continue doing fadump. 73 */ 74 int __init fadump_cma_init(void) 75 { 76 unsigned long long base, size; 77 int rc; 78 79 if (!fw_dump.fadump_enabled) 80 return 0; 81 82 /* 83 * Do not use CMA if user has provided fadump=nocma kernel parameter. 84 * Return 1 to continue with fadump old behaviour. 85 */ 86 if (fw_dump.nocma) 87 return 1; 88 89 base = fw_dump.reserve_dump_area_start; 90 size = fw_dump.boot_memory_size; 91 92 if (!size) 93 return 0; 94 95 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma); 96 if (rc) { 97 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc); 98 /* 99 * Though the CMA init has failed we still have memory 100 * reservation with us. The reserved memory will be 101 * blocked from production system usage. Hence return 1, 102 * so that we can continue with fadump. 103 */ 104 return 1; 105 } 106 107 /* 108 * So we now have successfully initialized cma area for fadump. 109 */ 110 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx " 111 "bytes of memory reserved for firmware-assisted dump\n", 112 cma_get_size(fadump_cma), 113 (unsigned long)cma_get_base(fadump_cma) >> 20, 114 fw_dump.reserve_dump_area_size); 115 return 1; 116 } 117 #else 118 static int __init fadump_cma_init(void) { return 1; } 119 #endif /* CONFIG_CMA */ 120 121 /* Scan the Firmware Assisted dump configuration details. */ 122 int __init early_init_dt_scan_fw_dump(unsigned long node, 123 const char *uname, int depth, void *data) 124 { 125 const __be32 *sections; 126 int i, num_sections; 127 int size; 128 const __be32 *token; 129 130 if (depth != 1 || strcmp(uname, "rtas") != 0) 131 return 0; 132 133 /* 134 * Check if Firmware Assisted dump is supported. if yes, check 135 * if dump has been initiated on last reboot. 136 */ 137 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 138 if (!token) 139 return 1; 140 141 fw_dump.fadump_supported = 1; 142 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 143 144 /* 145 * The 'ibm,kernel-dump' rtas node is present only if there is 146 * dump data waiting for us. 147 */ 148 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 149 if (fdm_active) 150 fw_dump.dump_active = 1; 151 152 /* Get the sizes required to store dump data for the firmware provided 153 * dump sections. 154 * For each dump section type supported, a 32bit cell which defines 155 * the ID of a supported section followed by two 32 bit cells which 156 * gives teh size of the section in bytes. 157 */ 158 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 159 &size); 160 161 if (!sections) 162 return 1; 163 164 num_sections = size / (3 * sizeof(u32)); 165 166 for (i = 0; i < num_sections; i++, sections += 3) { 167 u32 type = (u32)of_read_number(sections, 1); 168 169 switch (type) { 170 case FADUMP_CPU_STATE_DATA: 171 fw_dump.cpu_state_data_size = 172 of_read_ulong(§ions[1], 2); 173 break; 174 case FADUMP_HPTE_REGION: 175 fw_dump.hpte_region_size = 176 of_read_ulong(§ions[1], 2); 177 break; 178 } 179 } 180 181 return 1; 182 } 183 184 /* 185 * If fadump is registered, check if the memory provided 186 * falls within boot memory area and reserved memory area. 187 */ 188 int is_fadump_memory_area(u64 addr, ulong size) 189 { 190 u64 d_start = fw_dump.reserve_dump_area_start; 191 u64 d_end = d_start + fw_dump.reserve_dump_area_size; 192 193 if (!fw_dump.dump_registered) 194 return 0; 195 196 if (((addr + size) > d_start) && (addr <= d_end)) 197 return 1; 198 199 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; 200 } 201 202 int should_fadump_crash(void) 203 { 204 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 205 return 0; 206 return 1; 207 } 208 209 int is_fadump_active(void) 210 { 211 return fw_dump.dump_active; 212 } 213 214 /* 215 * Returns 1, if there are no holes in boot memory area, 216 * 0 otherwise. 217 */ 218 static int is_boot_memory_area_contiguous(void) 219 { 220 struct memblock_region *reg; 221 unsigned long tstart, tend; 222 unsigned long start_pfn = PHYS_PFN(RMA_START); 223 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size); 224 unsigned int ret = 0; 225 226 for_each_memblock(memory, reg) { 227 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 228 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 229 if (tstart < tend) { 230 /* Memory hole from start_pfn to tstart */ 231 if (tstart > start_pfn) 232 break; 233 234 if (tend == end_pfn) { 235 ret = 1; 236 break; 237 } 238 239 start_pfn = tend + 1; 240 } 241 } 242 243 return ret; 244 } 245 246 /* 247 * Returns true, if there are no holes in reserved memory area, 248 * false otherwise. 249 */ 250 static bool is_reserved_memory_area_contiguous(void) 251 { 252 struct memblock_region *reg; 253 unsigned long start, end; 254 unsigned long d_start = fw_dump.reserve_dump_area_start; 255 unsigned long d_end = d_start + fw_dump.reserve_dump_area_size; 256 257 for_each_memblock(memory, reg) { 258 start = max(d_start, (unsigned long)reg->base); 259 end = min(d_end, (unsigned long)(reg->base + reg->size)); 260 if (d_start < end) { 261 /* Memory hole from d_start to start */ 262 if (start > d_start) 263 break; 264 265 if (end == d_end) 266 return true; 267 268 d_start = end + 1; 269 } 270 } 271 272 return false; 273 } 274 275 /* Print firmware assisted dump configurations for debugging purpose. */ 276 static void fadump_show_config(void) 277 { 278 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 279 (fw_dump.fadump_supported ? "present" : "no support")); 280 281 if (!fw_dump.fadump_supported) 282 return; 283 284 pr_debug("Fadump enabled : %s\n", 285 (fw_dump.fadump_enabled ? "yes" : "no")); 286 pr_debug("Dump Active : %s\n", 287 (fw_dump.dump_active ? "yes" : "no")); 288 pr_debug("Dump section sizes:\n"); 289 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 290 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 291 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 292 } 293 294 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 295 unsigned long addr) 296 { 297 if (!fdm) 298 return 0; 299 300 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 301 addr = addr & PAGE_MASK; 302 303 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 304 fdm->header.dump_num_sections = cpu_to_be16(3); 305 fdm->header.dump_status_flag = 0; 306 fdm->header.offset_first_dump_section = 307 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 308 309 /* 310 * Fields for disk dump option. 311 * We are not using disk dump option, hence set these fields to 0. 312 */ 313 fdm->header.dd_block_size = 0; 314 fdm->header.dd_block_offset = 0; 315 fdm->header.dd_num_blocks = 0; 316 fdm->header.dd_offset_disk_path = 0; 317 318 /* set 0 to disable an automatic dump-reboot. */ 319 fdm->header.max_time_auto = 0; 320 321 /* Kernel dump sections */ 322 /* cpu state data section. */ 323 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 324 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 325 fdm->cpu_state_data.source_address = 0; 326 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 327 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 328 addr += fw_dump.cpu_state_data_size; 329 330 /* hpte region section */ 331 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 332 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 333 fdm->hpte_region.source_address = 0; 334 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 335 fdm->hpte_region.destination_address = cpu_to_be64(addr); 336 addr += fw_dump.hpte_region_size; 337 338 /* RMA region section */ 339 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 340 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 341 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 342 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 343 fdm->rmr_region.destination_address = cpu_to_be64(addr); 344 addr += fw_dump.boot_memory_size; 345 346 return addr; 347 } 348 349 /** 350 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 351 * 352 * Function to find the largest memory size we need to reserve during early 353 * boot process. This will be the size of the memory that is required for a 354 * kernel to boot successfully. 355 * 356 * This function has been taken from phyp-assisted dump feature implementation. 357 * 358 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 359 * 360 * TODO: Come up with better approach to find out more accurate memory size 361 * that is required for a kernel to boot successfully. 362 * 363 */ 364 static inline unsigned long fadump_calculate_reserve_size(void) 365 { 366 int ret; 367 unsigned long long base, size; 368 369 if (fw_dump.reserve_bootvar) 370 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 371 372 /* 373 * Check if the size is specified through crashkernel= cmdline 374 * option. If yes, then use that but ignore base as fadump reserves 375 * memory at a predefined offset. 376 */ 377 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 378 &size, &base); 379 if (ret == 0 && size > 0) { 380 unsigned long max_size; 381 382 if (fw_dump.reserve_bootvar) 383 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 384 385 fw_dump.reserve_bootvar = (unsigned long)size; 386 387 /* 388 * Adjust if the boot memory size specified is above 389 * the upper limit. 390 */ 391 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 392 if (fw_dump.reserve_bootvar > max_size) { 393 fw_dump.reserve_bootvar = max_size; 394 pr_info("Adjusted boot memory size to %luMB\n", 395 (fw_dump.reserve_bootvar >> 20)); 396 } 397 398 return fw_dump.reserve_bootvar; 399 } else if (fw_dump.reserve_bootvar) { 400 /* 401 * 'fadump_reserve_mem=' is being used to reserve memory 402 * for firmware-assisted dump. 403 */ 404 return fw_dump.reserve_bootvar; 405 } 406 407 /* divide by 20 to get 5% of value */ 408 size = memblock_phys_mem_size() / 20; 409 410 /* round it down in multiples of 256 */ 411 size = size & ~0x0FFFFFFFUL; 412 413 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 414 if (memory_limit && size > memory_limit) 415 size = memory_limit; 416 417 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 418 } 419 420 /* 421 * Calculate the total memory size required to be reserved for 422 * firmware-assisted dump registration. 423 */ 424 static unsigned long get_fadump_area_size(void) 425 { 426 unsigned long size = 0; 427 428 size += fw_dump.cpu_state_data_size; 429 size += fw_dump.hpte_region_size; 430 size += fw_dump.boot_memory_size; 431 size += sizeof(struct fadump_crash_info_header); 432 size += sizeof(struct elfhdr); /* ELF core header.*/ 433 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 434 /* Program headers for crash memory regions. */ 435 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 436 437 size = PAGE_ALIGN(size); 438 return size; 439 } 440 441 static void __init fadump_reserve_crash_area(unsigned long base, 442 unsigned long size) 443 { 444 struct memblock_region *reg; 445 unsigned long mstart, mend, msize; 446 447 for_each_memblock(memory, reg) { 448 mstart = max_t(unsigned long, base, reg->base); 449 mend = reg->base + reg->size; 450 mend = min(base + size, mend); 451 452 if (mstart < mend) { 453 msize = mend - mstart; 454 memblock_reserve(mstart, msize); 455 pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n", 456 (msize >> 20), mstart); 457 } 458 } 459 } 460 461 int __init fadump_reserve_mem(void) 462 { 463 unsigned long base, size, memory_boundary; 464 465 if (!fw_dump.fadump_enabled) 466 return 0; 467 468 if (!fw_dump.fadump_supported) { 469 printk(KERN_INFO "Firmware-assisted dump is not supported on" 470 " this hardware\n"); 471 fw_dump.fadump_enabled = 0; 472 return 0; 473 } 474 /* 475 * Initialize boot memory size 476 * If dump is active then we have already calculated the size during 477 * first kernel. 478 */ 479 if (fdm_active) 480 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 481 else { 482 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 483 #ifdef CONFIG_CMA 484 if (!fw_dump.nocma) 485 fw_dump.boot_memory_size = 486 ALIGN(fw_dump.boot_memory_size, 487 FADUMP_CMA_ALIGNMENT); 488 #endif 489 } 490 491 /* 492 * Calculate the memory boundary. 493 * If memory_limit is less than actual memory boundary then reserve 494 * the memory for fadump beyond the memory_limit and adjust the 495 * memory_limit accordingly, so that the running kernel can run with 496 * specified memory_limit. 497 */ 498 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 499 size = get_fadump_area_size(); 500 if ((memory_limit + size) < memblock_end_of_DRAM()) 501 memory_limit += size; 502 else 503 memory_limit = memblock_end_of_DRAM(); 504 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 505 " dump, now %#016llx\n", memory_limit); 506 } 507 if (memory_limit) 508 memory_boundary = memory_limit; 509 else 510 memory_boundary = memblock_end_of_DRAM(); 511 512 if (fw_dump.dump_active) { 513 pr_info("Firmware-assisted dump is active.\n"); 514 515 #ifdef CONFIG_HUGETLB_PAGE 516 /* 517 * FADump capture kernel doesn't care much about hugepages. 518 * In fact, handling hugepages in capture kernel is asking for 519 * trouble. So, disable HugeTLB support when fadump is active. 520 */ 521 hugetlb_disabled = true; 522 #endif 523 /* 524 * If last boot has crashed then reserve all the memory 525 * above boot_memory_size so that we don't touch it until 526 * dump is written to disk by userspace tool. This memory 527 * will be released for general use once the dump is saved. 528 */ 529 base = fw_dump.boot_memory_size; 530 size = memory_boundary - base; 531 fadump_reserve_crash_area(base, size); 532 533 fw_dump.fadumphdr_addr = 534 be64_to_cpu(fdm_active->rmr_region.destination_address) + 535 be64_to_cpu(fdm_active->rmr_region.source_len); 536 pr_debug("fadumphdr_addr = %pa\n", &fw_dump.fadumphdr_addr); 537 fw_dump.reserve_dump_area_start = base; 538 fw_dump.reserve_dump_area_size = size; 539 } else { 540 size = get_fadump_area_size(); 541 542 /* 543 * Reserve memory at an offset closer to bottom of the RAM to 544 * minimize the impact of memory hot-remove operation. We can't 545 * use memblock_find_in_range() here since it doesn't allocate 546 * from bottom to top. 547 */ 548 for (base = fw_dump.boot_memory_size; 549 base <= (memory_boundary - size); 550 base += size) { 551 if (memblock_is_region_memory(base, size) && 552 !memblock_is_region_reserved(base, size)) 553 break; 554 } 555 if ((base > (memory_boundary - size)) || 556 memblock_reserve(base, size)) { 557 pr_err("Failed to reserve memory\n"); 558 return 0; 559 } 560 561 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 562 "assisted dump (System RAM: %ldMB)\n", 563 (unsigned long)(size >> 20), 564 (unsigned long)(base >> 20), 565 (unsigned long)(memblock_phys_mem_size() >> 20)); 566 567 fw_dump.reserve_dump_area_start = base; 568 fw_dump.reserve_dump_area_size = size; 569 return fadump_cma_init(); 570 } 571 return 1; 572 } 573 574 unsigned long __init arch_reserved_kernel_pages(void) 575 { 576 return memblock_reserved_size() / PAGE_SIZE; 577 } 578 579 /* Look for fadump= cmdline option. */ 580 static int __init early_fadump_param(char *p) 581 { 582 if (!p) 583 return 1; 584 585 if (strncmp(p, "on", 2) == 0) 586 fw_dump.fadump_enabled = 1; 587 else if (strncmp(p, "off", 3) == 0) 588 fw_dump.fadump_enabled = 0; 589 else if (strncmp(p, "nocma", 5) == 0) { 590 fw_dump.fadump_enabled = 1; 591 fw_dump.nocma = 1; 592 } 593 594 return 0; 595 } 596 early_param("fadump", early_fadump_param); 597 598 /* 599 * Look for fadump_reserve_mem= cmdline option 600 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 601 * the sooner 'crashkernel=' parameter is accustomed to. 602 */ 603 static int __init early_fadump_reserve_mem(char *p) 604 { 605 if (p) 606 fw_dump.reserve_bootvar = memparse(p, &p); 607 return 0; 608 } 609 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 610 611 static int register_fw_dump(struct fadump_mem_struct *fdm) 612 { 613 int rc, err; 614 unsigned int wait_time; 615 616 pr_debug("Registering for firmware-assisted kernel dump...\n"); 617 618 /* TODO: Add upper time limit for the delay */ 619 do { 620 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 621 FADUMP_REGISTER, fdm, 622 sizeof(struct fadump_mem_struct)); 623 624 wait_time = rtas_busy_delay_time(rc); 625 if (wait_time) 626 mdelay(wait_time); 627 628 } while (wait_time); 629 630 err = -EIO; 631 switch (rc) { 632 default: 633 pr_err("Failed to register. Unknown Error(%d).\n", rc); 634 break; 635 case -1: 636 printk(KERN_ERR "Failed to register firmware-assisted kernel" 637 " dump. Hardware Error(%d).\n", rc); 638 break; 639 case -3: 640 if (!is_boot_memory_area_contiguous()) 641 pr_err("Can't have holes in boot memory area while registering fadump\n"); 642 else if (!is_reserved_memory_area_contiguous()) 643 pr_err("Can't have holes in reserved memory area while" 644 " registering fadump\n"); 645 646 printk(KERN_ERR "Failed to register firmware-assisted kernel" 647 " dump. Parameter Error(%d).\n", rc); 648 err = -EINVAL; 649 break; 650 case -9: 651 printk(KERN_ERR "firmware-assisted kernel dump is already " 652 " registered."); 653 fw_dump.dump_registered = 1; 654 err = -EEXIST; 655 break; 656 case 0: 657 printk(KERN_INFO "firmware-assisted kernel dump registration" 658 " is successful\n"); 659 fw_dump.dump_registered = 1; 660 err = 0; 661 break; 662 } 663 return err; 664 } 665 666 void crash_fadump(struct pt_regs *regs, const char *str) 667 { 668 struct fadump_crash_info_header *fdh = NULL; 669 int old_cpu, this_cpu; 670 671 if (!should_fadump_crash()) 672 return; 673 674 /* 675 * old_cpu == -1 means this is the first CPU which has come here, 676 * go ahead and trigger fadump. 677 * 678 * old_cpu != -1 means some other CPU has already on it's way 679 * to trigger fadump, just keep looping here. 680 */ 681 this_cpu = smp_processor_id(); 682 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 683 684 if (old_cpu != -1) { 685 /* 686 * We can't loop here indefinitely. Wait as long as fadump 687 * is in force. If we race with fadump un-registration this 688 * loop will break and then we go down to normal panic path 689 * and reboot. If fadump is in force the first crashing 690 * cpu will definitely trigger fadump. 691 */ 692 while (fw_dump.dump_registered) 693 cpu_relax(); 694 return; 695 } 696 697 fdh = __va(fw_dump.fadumphdr_addr); 698 fdh->crashing_cpu = crashing_cpu; 699 crash_save_vmcoreinfo(); 700 701 if (regs) 702 fdh->regs = *regs; 703 else 704 ppc_save_regs(&fdh->regs); 705 706 fdh->online_mask = *cpu_online_mask; 707 708 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 709 rtas_os_term((char *)str); 710 } 711 712 #define GPR_MASK 0xffffff0000000000 713 static inline int fadump_gpr_index(u64 id) 714 { 715 int i = -1; 716 char str[3]; 717 718 if ((id & GPR_MASK) == REG_ID("GPR")) { 719 /* get the digits at the end */ 720 id &= ~GPR_MASK; 721 id >>= 24; 722 str[2] = '\0'; 723 str[1] = id & 0xff; 724 str[0] = (id >> 8) & 0xff; 725 sscanf(str, "%d", &i); 726 if (i > 31) 727 i = -1; 728 } 729 return i; 730 } 731 732 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 733 u64 reg_val) 734 { 735 int i; 736 737 i = fadump_gpr_index(reg_id); 738 if (i >= 0) 739 regs->gpr[i] = (unsigned long)reg_val; 740 else if (reg_id == REG_ID("NIA")) 741 regs->nip = (unsigned long)reg_val; 742 else if (reg_id == REG_ID("MSR")) 743 regs->msr = (unsigned long)reg_val; 744 else if (reg_id == REG_ID("CTR")) 745 regs->ctr = (unsigned long)reg_val; 746 else if (reg_id == REG_ID("LR")) 747 regs->link = (unsigned long)reg_val; 748 else if (reg_id == REG_ID("XER")) 749 regs->xer = (unsigned long)reg_val; 750 else if (reg_id == REG_ID("CR")) 751 regs->ccr = (unsigned long)reg_val; 752 else if (reg_id == REG_ID("DAR")) 753 regs->dar = (unsigned long)reg_val; 754 else if (reg_id == REG_ID("DSISR")) 755 regs->dsisr = (unsigned long)reg_val; 756 } 757 758 static struct fadump_reg_entry* 759 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 760 { 761 memset(regs, 0, sizeof(struct pt_regs)); 762 763 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 764 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 765 be64_to_cpu(reg_entry->reg_value)); 766 reg_entry++; 767 } 768 reg_entry++; 769 return reg_entry; 770 } 771 772 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 773 { 774 struct elf_prstatus prstatus; 775 776 memset(&prstatus, 0, sizeof(prstatus)); 777 /* 778 * FIXME: How do i get PID? Do I really need it? 779 * prstatus.pr_pid = ???? 780 */ 781 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 782 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 783 &prstatus, sizeof(prstatus)); 784 return buf; 785 } 786 787 static void fadump_update_elfcore_header(char *bufp) 788 { 789 struct elfhdr *elf; 790 struct elf_phdr *phdr; 791 792 elf = (struct elfhdr *)bufp; 793 bufp += sizeof(struct elfhdr); 794 795 /* First note is a place holder for cpu notes info. */ 796 phdr = (struct elf_phdr *)bufp; 797 798 if (phdr->p_type == PT_NOTE) { 799 phdr->p_paddr = fw_dump.cpu_notes_buf; 800 phdr->p_offset = phdr->p_paddr; 801 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 802 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 803 } 804 return; 805 } 806 807 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 808 { 809 void *vaddr; 810 struct page *page; 811 unsigned long order, count, i; 812 813 order = get_order(size); 814 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 815 if (!vaddr) 816 return NULL; 817 818 count = 1 << order; 819 page = virt_to_page(vaddr); 820 for (i = 0; i < count; i++) 821 SetPageReserved(page + i); 822 return vaddr; 823 } 824 825 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 826 { 827 struct page *page; 828 unsigned long order, count, i; 829 830 order = get_order(size); 831 count = 1 << order; 832 page = virt_to_page(vaddr); 833 for (i = 0; i < count; i++) 834 ClearPageReserved(page + i); 835 __free_pages(page, order); 836 } 837 838 /* 839 * Read CPU state dump data and convert it into ELF notes. 840 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 841 * used to access the data to allow for additional fields to be added without 842 * affecting compatibility. Each list of registers for a CPU starts with 843 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 844 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 845 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 846 * of register value. For more details refer to PAPR document. 847 * 848 * Only for the crashing cpu we ignore the CPU dump data and get exact 849 * state from fadump crash info structure populated by first kernel at the 850 * time of crash. 851 */ 852 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 853 { 854 struct fadump_reg_save_area_header *reg_header; 855 struct fadump_reg_entry *reg_entry; 856 struct fadump_crash_info_header *fdh = NULL; 857 void *vaddr; 858 unsigned long addr; 859 u32 num_cpus, *note_buf; 860 struct pt_regs regs; 861 int i, rc = 0, cpu = 0; 862 863 if (!fdm->cpu_state_data.bytes_dumped) 864 return -EINVAL; 865 866 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 867 vaddr = __va(addr); 868 869 reg_header = vaddr; 870 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 871 printk(KERN_ERR "Unable to read register save area.\n"); 872 return -ENOENT; 873 } 874 pr_debug("--------CPU State Data------------\n"); 875 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 876 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 877 878 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 879 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 880 pr_debug("NumCpus : %u\n", num_cpus); 881 vaddr += sizeof(u32); 882 reg_entry = (struct fadump_reg_entry *)vaddr; 883 884 /* Allocate buffer to hold cpu crash notes. */ 885 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 886 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 887 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 888 if (!note_buf) { 889 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 890 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 891 return -ENOMEM; 892 } 893 fw_dump.cpu_notes_buf = __pa(note_buf); 894 895 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 896 (num_cpus * sizeof(note_buf_t)), note_buf); 897 898 if (fw_dump.fadumphdr_addr) 899 fdh = __va(fw_dump.fadumphdr_addr); 900 901 for (i = 0; i < num_cpus; i++) { 902 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 903 printk(KERN_ERR "Unable to read CPU state data\n"); 904 rc = -ENOENT; 905 goto error_out; 906 } 907 /* Lower 4 bytes of reg_value contains logical cpu id */ 908 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 909 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 910 SKIP_TO_NEXT_CPU(reg_entry); 911 continue; 912 } 913 pr_debug("Reading register data for cpu %d...\n", cpu); 914 if (fdh && fdh->crashing_cpu == cpu) { 915 regs = fdh->regs; 916 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 917 SKIP_TO_NEXT_CPU(reg_entry); 918 } else { 919 reg_entry++; 920 reg_entry = fadump_read_registers(reg_entry, ®s); 921 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 922 } 923 } 924 final_note(note_buf); 925 926 if (fdh) { 927 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 928 fdh->elfcorehdr_addr); 929 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 930 } 931 return 0; 932 933 error_out: 934 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 935 fw_dump.cpu_notes_buf_size); 936 fw_dump.cpu_notes_buf = 0; 937 fw_dump.cpu_notes_buf_size = 0; 938 return rc; 939 940 } 941 942 /* 943 * Validate and process the dump data stored by firmware before exporting 944 * it through '/proc/vmcore'. 945 */ 946 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 947 { 948 struct fadump_crash_info_header *fdh; 949 int rc = 0; 950 951 if (!fdm_active || !fw_dump.fadumphdr_addr) 952 return -EINVAL; 953 954 /* Check if the dump data is valid. */ 955 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 956 (fdm_active->cpu_state_data.error_flags != 0) || 957 (fdm_active->rmr_region.error_flags != 0)) { 958 printk(KERN_ERR "Dump taken by platform is not valid\n"); 959 return -EINVAL; 960 } 961 if ((fdm_active->rmr_region.bytes_dumped != 962 fdm_active->rmr_region.source_len) || 963 !fdm_active->cpu_state_data.bytes_dumped) { 964 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 965 return -EINVAL; 966 } 967 968 /* Validate the fadump crash info header */ 969 fdh = __va(fw_dump.fadumphdr_addr); 970 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 971 printk(KERN_ERR "Crash info header is not valid.\n"); 972 return -EINVAL; 973 } 974 975 rc = fadump_build_cpu_notes(fdm_active); 976 if (rc) 977 return rc; 978 979 /* 980 * We are done validating dump info and elfcore header is now ready 981 * to be exported. set elfcorehdr_addr so that vmcore module will 982 * export the elfcore header through '/proc/vmcore'. 983 */ 984 elfcorehdr_addr = fdh->elfcorehdr_addr; 985 986 return 0; 987 } 988 989 static void free_crash_memory_ranges(void) 990 { 991 kfree(crash_memory_ranges); 992 crash_memory_ranges = NULL; 993 crash_memory_ranges_size = 0; 994 max_crash_mem_ranges = 0; 995 } 996 997 /* 998 * Allocate or reallocate crash memory ranges array in incremental units 999 * of PAGE_SIZE. 1000 */ 1001 static int allocate_crash_memory_ranges(void) 1002 { 1003 struct fad_crash_memory_ranges *new_array; 1004 u64 new_size; 1005 1006 new_size = crash_memory_ranges_size + PAGE_SIZE; 1007 pr_debug("Allocating %llu bytes of memory for crash memory ranges\n", 1008 new_size); 1009 1010 new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL); 1011 if (new_array == NULL) { 1012 pr_err("Insufficient memory for setting up crash memory ranges\n"); 1013 free_crash_memory_ranges(); 1014 return -ENOMEM; 1015 } 1016 1017 crash_memory_ranges = new_array; 1018 crash_memory_ranges_size = new_size; 1019 max_crash_mem_ranges = (new_size / 1020 sizeof(struct fad_crash_memory_ranges)); 1021 return 0; 1022 } 1023 1024 static inline int fadump_add_crash_memory(unsigned long long base, 1025 unsigned long long end) 1026 { 1027 u64 start, size; 1028 bool is_adjacent = false; 1029 1030 if (base == end) 1031 return 0; 1032 1033 /* 1034 * Fold adjacent memory ranges to bring down the memory ranges/ 1035 * PT_LOAD segments count. 1036 */ 1037 if (crash_mem_ranges) { 1038 start = crash_memory_ranges[crash_mem_ranges - 1].base; 1039 size = crash_memory_ranges[crash_mem_ranges - 1].size; 1040 1041 if ((start + size) == base) 1042 is_adjacent = true; 1043 } 1044 if (!is_adjacent) { 1045 /* resize the array on reaching the limit */ 1046 if (crash_mem_ranges == max_crash_mem_ranges) { 1047 int ret; 1048 1049 ret = allocate_crash_memory_ranges(); 1050 if (ret) 1051 return ret; 1052 } 1053 1054 start = base; 1055 crash_memory_ranges[crash_mem_ranges].base = start; 1056 crash_mem_ranges++; 1057 } 1058 1059 crash_memory_ranges[crash_mem_ranges - 1].size = (end - start); 1060 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 1061 (crash_mem_ranges - 1), start, end - 1, (end - start)); 1062 return 0; 1063 } 1064 1065 static int fadump_exclude_reserved_area(unsigned long long start, 1066 unsigned long long end) 1067 { 1068 unsigned long long ra_start, ra_end; 1069 int ret = 0; 1070 1071 ra_start = fw_dump.reserve_dump_area_start; 1072 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1073 1074 if ((ra_start < end) && (ra_end > start)) { 1075 if ((start < ra_start) && (end > ra_end)) { 1076 ret = fadump_add_crash_memory(start, ra_start); 1077 if (ret) 1078 return ret; 1079 1080 ret = fadump_add_crash_memory(ra_end, end); 1081 } else if (start < ra_start) { 1082 ret = fadump_add_crash_memory(start, ra_start); 1083 } else if (ra_end < end) { 1084 ret = fadump_add_crash_memory(ra_end, end); 1085 } 1086 } else 1087 ret = fadump_add_crash_memory(start, end); 1088 1089 return ret; 1090 } 1091 1092 static int fadump_init_elfcore_header(char *bufp) 1093 { 1094 struct elfhdr *elf; 1095 1096 elf = (struct elfhdr *) bufp; 1097 bufp += sizeof(struct elfhdr); 1098 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1099 elf->e_ident[EI_CLASS] = ELF_CLASS; 1100 elf->e_ident[EI_DATA] = ELF_DATA; 1101 elf->e_ident[EI_VERSION] = EV_CURRENT; 1102 elf->e_ident[EI_OSABI] = ELF_OSABI; 1103 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1104 elf->e_type = ET_CORE; 1105 elf->e_machine = ELF_ARCH; 1106 elf->e_version = EV_CURRENT; 1107 elf->e_entry = 0; 1108 elf->e_phoff = sizeof(struct elfhdr); 1109 elf->e_shoff = 0; 1110 #if defined(_CALL_ELF) 1111 elf->e_flags = _CALL_ELF; 1112 #else 1113 elf->e_flags = 0; 1114 #endif 1115 elf->e_ehsize = sizeof(struct elfhdr); 1116 elf->e_phentsize = sizeof(struct elf_phdr); 1117 elf->e_phnum = 0; 1118 elf->e_shentsize = 0; 1119 elf->e_shnum = 0; 1120 elf->e_shstrndx = 0; 1121 1122 return 0; 1123 } 1124 1125 /* 1126 * Traverse through memblock structure and setup crash memory ranges. These 1127 * ranges will be used create PT_LOAD program headers in elfcore header. 1128 */ 1129 static int fadump_setup_crash_memory_ranges(void) 1130 { 1131 struct memblock_region *reg; 1132 unsigned long long start, end; 1133 int ret; 1134 1135 pr_debug("Setup crash memory ranges.\n"); 1136 crash_mem_ranges = 0; 1137 1138 /* 1139 * add the first memory chunk (RMA_START through boot_memory_size) as 1140 * a separate memory chunk. The reason is, at the time crash firmware 1141 * will move the content of this memory chunk to different location 1142 * specified during fadump registration. We need to create a separate 1143 * program header for this chunk with the correct offset. 1144 */ 1145 ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 1146 if (ret) 1147 return ret; 1148 1149 for_each_memblock(memory, reg) { 1150 start = (unsigned long long)reg->base; 1151 end = start + (unsigned long long)reg->size; 1152 1153 /* 1154 * skip the first memory chunk that is already added (RMA_START 1155 * through boot_memory_size). This logic needs a relook if and 1156 * when RMA_START changes to a non-zero value. 1157 */ 1158 BUILD_BUG_ON(RMA_START != 0); 1159 if (start < fw_dump.boot_memory_size) { 1160 if (end > fw_dump.boot_memory_size) 1161 start = fw_dump.boot_memory_size; 1162 else 1163 continue; 1164 } 1165 1166 /* add this range excluding the reserved dump area. */ 1167 ret = fadump_exclude_reserved_area(start, end); 1168 if (ret) 1169 return ret; 1170 } 1171 1172 return 0; 1173 } 1174 1175 /* 1176 * If the given physical address falls within the boot memory region then 1177 * return the relocated address that points to the dump region reserved 1178 * for saving initial boot memory contents. 1179 */ 1180 static inline unsigned long fadump_relocate(unsigned long paddr) 1181 { 1182 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 1183 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 1184 else 1185 return paddr; 1186 } 1187 1188 static int fadump_create_elfcore_headers(char *bufp) 1189 { 1190 struct elfhdr *elf; 1191 struct elf_phdr *phdr; 1192 int i; 1193 1194 fadump_init_elfcore_header(bufp); 1195 elf = (struct elfhdr *)bufp; 1196 bufp += sizeof(struct elfhdr); 1197 1198 /* 1199 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1200 * will be populated during second kernel boot after crash. Hence 1201 * this PT_NOTE will always be the first elf note. 1202 * 1203 * NOTE: Any new ELF note addition should be placed after this note. 1204 */ 1205 phdr = (struct elf_phdr *)bufp; 1206 bufp += sizeof(struct elf_phdr); 1207 phdr->p_type = PT_NOTE; 1208 phdr->p_flags = 0; 1209 phdr->p_vaddr = 0; 1210 phdr->p_align = 0; 1211 1212 phdr->p_offset = 0; 1213 phdr->p_paddr = 0; 1214 phdr->p_filesz = 0; 1215 phdr->p_memsz = 0; 1216 1217 (elf->e_phnum)++; 1218 1219 /* setup ELF PT_NOTE for vmcoreinfo */ 1220 phdr = (struct elf_phdr *)bufp; 1221 bufp += sizeof(struct elf_phdr); 1222 phdr->p_type = PT_NOTE; 1223 phdr->p_flags = 0; 1224 phdr->p_vaddr = 0; 1225 phdr->p_align = 0; 1226 1227 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1228 phdr->p_offset = phdr->p_paddr; 1229 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1230 1231 /* Increment number of program headers. */ 1232 (elf->e_phnum)++; 1233 1234 /* setup PT_LOAD sections. */ 1235 1236 for (i = 0; i < crash_mem_ranges; i++) { 1237 unsigned long long mbase, msize; 1238 mbase = crash_memory_ranges[i].base; 1239 msize = crash_memory_ranges[i].size; 1240 1241 if (!msize) 1242 continue; 1243 1244 phdr = (struct elf_phdr *)bufp; 1245 bufp += sizeof(struct elf_phdr); 1246 phdr->p_type = PT_LOAD; 1247 phdr->p_flags = PF_R|PF_W|PF_X; 1248 phdr->p_offset = mbase; 1249 1250 if (mbase == RMA_START) { 1251 /* 1252 * The entire RMA region will be moved by firmware 1253 * to the specified destination_address. Hence set 1254 * the correct offset. 1255 */ 1256 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1257 } 1258 1259 phdr->p_paddr = mbase; 1260 phdr->p_vaddr = (unsigned long)__va(mbase); 1261 phdr->p_filesz = msize; 1262 phdr->p_memsz = msize; 1263 phdr->p_align = 0; 1264 1265 /* Increment number of program headers. */ 1266 (elf->e_phnum)++; 1267 } 1268 return 0; 1269 } 1270 1271 static unsigned long init_fadump_header(unsigned long addr) 1272 { 1273 struct fadump_crash_info_header *fdh; 1274 1275 if (!addr) 1276 return 0; 1277 1278 fw_dump.fadumphdr_addr = addr; 1279 fdh = __va(addr); 1280 addr += sizeof(struct fadump_crash_info_header); 1281 1282 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1283 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1284 fdh->elfcorehdr_addr = addr; 1285 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1286 fdh->crashing_cpu = CPU_UNKNOWN; 1287 1288 return addr; 1289 } 1290 1291 static int register_fadump(void) 1292 { 1293 unsigned long addr; 1294 void *vaddr; 1295 int ret; 1296 1297 /* 1298 * If no memory is reserved then we can not register for firmware- 1299 * assisted dump. 1300 */ 1301 if (!fw_dump.reserve_dump_area_size) 1302 return -ENODEV; 1303 1304 ret = fadump_setup_crash_memory_ranges(); 1305 if (ret) 1306 return ret; 1307 1308 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1309 /* Initialize fadump crash info header. */ 1310 addr = init_fadump_header(addr); 1311 vaddr = __va(addr); 1312 1313 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1314 fadump_create_elfcore_headers(vaddr); 1315 1316 /* register the future kernel dump with firmware. */ 1317 return register_fw_dump(&fdm); 1318 } 1319 1320 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1321 { 1322 int rc = 0; 1323 unsigned int wait_time; 1324 1325 pr_debug("Un-register firmware-assisted dump\n"); 1326 1327 /* TODO: Add upper time limit for the delay */ 1328 do { 1329 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1330 FADUMP_UNREGISTER, fdm, 1331 sizeof(struct fadump_mem_struct)); 1332 1333 wait_time = rtas_busy_delay_time(rc); 1334 if (wait_time) 1335 mdelay(wait_time); 1336 } while (wait_time); 1337 1338 if (rc) { 1339 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1340 " unexpected error(%d).\n", rc); 1341 return rc; 1342 } 1343 fw_dump.dump_registered = 0; 1344 return 0; 1345 } 1346 1347 static int fadump_invalidate_dump(const struct fadump_mem_struct *fdm) 1348 { 1349 int rc = 0; 1350 unsigned int wait_time; 1351 1352 pr_debug("Invalidating firmware-assisted dump registration\n"); 1353 1354 /* TODO: Add upper time limit for the delay */ 1355 do { 1356 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1357 FADUMP_INVALIDATE, fdm, 1358 sizeof(struct fadump_mem_struct)); 1359 1360 wait_time = rtas_busy_delay_time(rc); 1361 if (wait_time) 1362 mdelay(wait_time); 1363 } while (wait_time); 1364 1365 if (rc) { 1366 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1367 return rc; 1368 } 1369 fw_dump.dump_active = 0; 1370 fdm_active = NULL; 1371 return 0; 1372 } 1373 1374 void fadump_cleanup(void) 1375 { 1376 /* Invalidate the registration only if dump is active. */ 1377 if (fw_dump.dump_active) { 1378 /* pass the same memory dump structure provided by platform */ 1379 fadump_invalidate_dump(fdm_active); 1380 } else if (fw_dump.dump_registered) { 1381 /* Un-register Firmware-assisted dump if it was registered. */ 1382 fadump_unregister_dump(&fdm); 1383 free_crash_memory_ranges(); 1384 } 1385 } 1386 1387 static void fadump_free_reserved_memory(unsigned long start_pfn, 1388 unsigned long end_pfn) 1389 { 1390 unsigned long pfn; 1391 unsigned long time_limit = jiffies + HZ; 1392 1393 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1394 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1395 1396 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1397 free_reserved_page(pfn_to_page(pfn)); 1398 1399 if (time_after(jiffies, time_limit)) { 1400 cond_resched(); 1401 time_limit = jiffies + HZ; 1402 } 1403 } 1404 } 1405 1406 /* 1407 * Skip memory holes and free memory that was actually reserved. 1408 */ 1409 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1410 { 1411 struct memblock_region *reg; 1412 unsigned long tstart, tend; 1413 unsigned long start_pfn = PHYS_PFN(start); 1414 unsigned long end_pfn = PHYS_PFN(end); 1415 1416 for_each_memblock(memory, reg) { 1417 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1418 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1419 if (tstart < tend) { 1420 fadump_free_reserved_memory(tstart, tend); 1421 1422 if (tend == end_pfn) 1423 break; 1424 1425 start_pfn = tend + 1; 1426 } 1427 } 1428 } 1429 1430 /* 1431 * Release the memory that was reserved in early boot to preserve the memory 1432 * contents. The released memory will be available for general use. 1433 */ 1434 static void fadump_release_memory(unsigned long begin, unsigned long end) 1435 { 1436 unsigned long ra_start, ra_end; 1437 1438 ra_start = fw_dump.reserve_dump_area_start; 1439 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1440 1441 /* 1442 * exclude the dump reserve area. Will reuse it for next 1443 * fadump registration. 1444 */ 1445 if (begin < ra_end && end > ra_start) { 1446 if (begin < ra_start) 1447 fadump_release_reserved_area(begin, ra_start); 1448 if (end > ra_end) 1449 fadump_release_reserved_area(ra_end, end); 1450 } else 1451 fadump_release_reserved_area(begin, end); 1452 } 1453 1454 static void fadump_invalidate_release_mem(void) 1455 { 1456 unsigned long reserved_area_start, reserved_area_end; 1457 unsigned long destination_address; 1458 1459 mutex_lock(&fadump_mutex); 1460 if (!fw_dump.dump_active) { 1461 mutex_unlock(&fadump_mutex); 1462 return; 1463 } 1464 1465 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1466 fadump_cleanup(); 1467 mutex_unlock(&fadump_mutex); 1468 1469 /* 1470 * Save the current reserved memory bounds we will require them 1471 * later for releasing the memory for general use. 1472 */ 1473 reserved_area_start = fw_dump.reserve_dump_area_start; 1474 reserved_area_end = reserved_area_start + 1475 fw_dump.reserve_dump_area_size; 1476 /* 1477 * Setup reserve_dump_area_start and its size so that we can 1478 * reuse this reserved memory for Re-registration. 1479 */ 1480 fw_dump.reserve_dump_area_start = destination_address; 1481 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1482 1483 fadump_release_memory(reserved_area_start, reserved_area_end); 1484 if (fw_dump.cpu_notes_buf) { 1485 fadump_cpu_notes_buf_free( 1486 (unsigned long)__va(fw_dump.cpu_notes_buf), 1487 fw_dump.cpu_notes_buf_size); 1488 fw_dump.cpu_notes_buf = 0; 1489 fw_dump.cpu_notes_buf_size = 0; 1490 } 1491 /* Initialize the kernel dump memory structure for FAD registration. */ 1492 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1493 } 1494 1495 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1496 struct kobj_attribute *attr, 1497 const char *buf, size_t count) 1498 { 1499 int input = -1; 1500 1501 if (!fw_dump.dump_active) 1502 return -EPERM; 1503 1504 if (kstrtoint(buf, 0, &input)) 1505 return -EINVAL; 1506 1507 if (input == 1) { 1508 /* 1509 * Take away the '/proc/vmcore'. We are releasing the dump 1510 * memory, hence it will not be valid anymore. 1511 */ 1512 #ifdef CONFIG_PROC_VMCORE 1513 vmcore_cleanup(); 1514 #endif 1515 fadump_invalidate_release_mem(); 1516 1517 } else 1518 return -EINVAL; 1519 return count; 1520 } 1521 1522 static ssize_t fadump_enabled_show(struct kobject *kobj, 1523 struct kobj_attribute *attr, 1524 char *buf) 1525 { 1526 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1527 } 1528 1529 static ssize_t fadump_register_show(struct kobject *kobj, 1530 struct kobj_attribute *attr, 1531 char *buf) 1532 { 1533 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1534 } 1535 1536 static ssize_t fadump_register_store(struct kobject *kobj, 1537 struct kobj_attribute *attr, 1538 const char *buf, size_t count) 1539 { 1540 int ret = 0; 1541 int input = -1; 1542 1543 if (!fw_dump.fadump_enabled || fdm_active) 1544 return -EPERM; 1545 1546 if (kstrtoint(buf, 0, &input)) 1547 return -EINVAL; 1548 1549 mutex_lock(&fadump_mutex); 1550 1551 switch (input) { 1552 case 0: 1553 if (fw_dump.dump_registered == 0) { 1554 goto unlock_out; 1555 } 1556 /* Un-register Firmware-assisted dump */ 1557 fadump_unregister_dump(&fdm); 1558 break; 1559 case 1: 1560 if (fw_dump.dump_registered == 1) { 1561 /* Un-register Firmware-assisted dump */ 1562 fadump_unregister_dump(&fdm); 1563 } 1564 /* Register Firmware-assisted dump */ 1565 ret = register_fadump(); 1566 break; 1567 default: 1568 ret = -EINVAL; 1569 break; 1570 } 1571 1572 unlock_out: 1573 mutex_unlock(&fadump_mutex); 1574 return ret < 0 ? ret : count; 1575 } 1576 1577 static int fadump_region_show(struct seq_file *m, void *private) 1578 { 1579 const struct fadump_mem_struct *fdm_ptr; 1580 1581 if (!fw_dump.fadump_enabled) 1582 return 0; 1583 1584 mutex_lock(&fadump_mutex); 1585 if (fdm_active) 1586 fdm_ptr = fdm_active; 1587 else { 1588 mutex_unlock(&fadump_mutex); 1589 fdm_ptr = &fdm; 1590 } 1591 1592 seq_printf(m, 1593 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1594 "Dumped: %#llx\n", 1595 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1596 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1597 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1598 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1599 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1600 seq_printf(m, 1601 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1602 "Dumped: %#llx\n", 1603 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1604 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1605 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1606 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1607 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1608 seq_printf(m, 1609 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1610 "Dumped: %#llx\n", 1611 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1612 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1613 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1614 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1615 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1616 1617 if (!fdm_active || 1618 (fw_dump.reserve_dump_area_start == 1619 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1620 goto out; 1621 1622 /* Dump is active. Show reserved memory region. */ 1623 seq_printf(m, 1624 " : [%#016llx-%#016llx] %#llx bytes, " 1625 "Dumped: %#llx\n", 1626 (unsigned long long)fw_dump.reserve_dump_area_start, 1627 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1628 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1629 fw_dump.reserve_dump_area_start, 1630 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1631 fw_dump.reserve_dump_area_start); 1632 out: 1633 if (fdm_active) 1634 mutex_unlock(&fadump_mutex); 1635 return 0; 1636 } 1637 1638 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1639 0200, NULL, 1640 fadump_release_memory_store); 1641 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1642 0444, fadump_enabled_show, 1643 NULL); 1644 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1645 0644, fadump_register_show, 1646 fadump_register_store); 1647 1648 DEFINE_SHOW_ATTRIBUTE(fadump_region); 1649 1650 static void fadump_init_files(void) 1651 { 1652 struct dentry *debugfs_file; 1653 int rc = 0; 1654 1655 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1656 if (rc) 1657 printk(KERN_ERR "fadump: unable to create sysfs file" 1658 " fadump_enabled (%d)\n", rc); 1659 1660 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1661 if (rc) 1662 printk(KERN_ERR "fadump: unable to create sysfs file" 1663 " fadump_registered (%d)\n", rc); 1664 1665 debugfs_file = debugfs_create_file("fadump_region", 0444, 1666 powerpc_debugfs_root, NULL, 1667 &fadump_region_fops); 1668 if (!debugfs_file) 1669 printk(KERN_ERR "fadump: unable to create debugfs file" 1670 " fadump_region\n"); 1671 1672 if (fw_dump.dump_active) { 1673 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1674 if (rc) 1675 printk(KERN_ERR "fadump: unable to create sysfs file" 1676 " fadump_release_mem (%d)\n", rc); 1677 } 1678 return; 1679 } 1680 1681 /* 1682 * Prepare for firmware-assisted dump. 1683 */ 1684 int __init setup_fadump(void) 1685 { 1686 if (!fw_dump.fadump_enabled) 1687 return 0; 1688 1689 if (!fw_dump.fadump_supported) { 1690 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1691 " this hardware\n"); 1692 return 0; 1693 } 1694 1695 fadump_show_config(); 1696 /* 1697 * If dump data is available then see if it is valid and prepare for 1698 * saving it to the disk. 1699 */ 1700 if (fw_dump.dump_active) { 1701 /* 1702 * if dump process fails then invalidate the registration 1703 * and release memory before proceeding for re-registration. 1704 */ 1705 if (process_fadump(fdm_active) < 0) 1706 fadump_invalidate_release_mem(); 1707 } 1708 /* Initialize the kernel dump memory structure for FAD registration. */ 1709 else if (fw_dump.reserve_dump_area_size) 1710 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1711 fadump_init_files(); 1712 1713 return 1; 1714 } 1715 subsys_initcall(setup_fadump); 1716