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 #include <linux/hugetlb.h> 40 41 #include <asm/debugfs.h> 42 #include <asm/page.h> 43 #include <asm/prom.h> 44 #include <asm/rtas.h> 45 #include <asm/fadump.h> 46 #include <asm/setup.h> 47 48 static struct fw_dump fw_dump; 49 static struct fadump_mem_struct fdm; 50 static const struct fadump_mem_struct *fdm_active; 51 #ifdef CONFIG_CMA 52 static struct cma *fadump_cma; 53 #endif 54 55 static DEFINE_MUTEX(fadump_mutex); 56 struct fad_crash_memory_ranges *crash_memory_ranges; 57 int crash_memory_ranges_size; 58 int crash_mem_ranges; 59 int max_crash_mem_ranges; 60 61 #ifdef CONFIG_CMA 62 /* 63 * fadump_cma_init() - Initialize CMA area from a fadump reserved memory 64 * 65 * This function initializes CMA area from fadump reserved memory. 66 * The total size of fadump reserved memory covers for boot memory size 67 * + cpu data size + hpte size and metadata. 68 * Initialize only the area equivalent to boot memory size for CMA use. 69 * The reamining portion of fadump reserved memory will be not given 70 * to CMA and pages for thoes will stay reserved. boot memory size is 71 * aligned per CMA requirement to satisy cma_init_reserved_mem() call. 72 * But for some reason even if it fails we still have the memory reservation 73 * with us and we can still continue doing fadump. 74 */ 75 int __init fadump_cma_init(void) 76 { 77 unsigned long long base, size; 78 int rc; 79 80 if (!fw_dump.fadump_enabled) 81 return 0; 82 83 /* 84 * Do not use CMA if user has provided fadump=nocma kernel parameter. 85 * Return 1 to continue with fadump old behaviour. 86 */ 87 if (fw_dump.nocma) 88 return 1; 89 90 base = fw_dump.reserve_dump_area_start; 91 size = fw_dump.boot_memory_size; 92 93 if (!size) 94 return 0; 95 96 rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma); 97 if (rc) { 98 pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc); 99 /* 100 * Though the CMA init has failed we still have memory 101 * reservation with us. The reserved memory will be 102 * blocked from production system usage. Hence return 1, 103 * so that we can continue with fadump. 104 */ 105 return 1; 106 } 107 108 /* 109 * So we now have successfully initialized cma area for fadump. 110 */ 111 pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx " 112 "bytes of memory reserved for firmware-assisted dump\n", 113 cma_get_size(fadump_cma), 114 (unsigned long)cma_get_base(fadump_cma) >> 20, 115 fw_dump.reserve_dump_area_size); 116 return 1; 117 } 118 #else 119 static int __init fadump_cma_init(void) { return 1; } 120 #endif /* CONFIG_CMA */ 121 122 /* Scan the Firmware Assisted dump configuration details. */ 123 int __init early_init_dt_scan_fw_dump(unsigned long node, 124 const char *uname, int depth, void *data) 125 { 126 const __be32 *sections; 127 int i, num_sections; 128 int size; 129 const __be32 *token; 130 131 if (depth != 1 || strcmp(uname, "rtas") != 0) 132 return 0; 133 134 /* 135 * Check if Firmware Assisted dump is supported. if yes, check 136 * if dump has been initiated on last reboot. 137 */ 138 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 139 if (!token) 140 return 1; 141 142 fw_dump.fadump_supported = 1; 143 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 144 145 /* 146 * The 'ibm,kernel-dump' rtas node is present only if there is 147 * dump data waiting for us. 148 */ 149 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 150 if (fdm_active) 151 fw_dump.dump_active = 1; 152 153 /* Get the sizes required to store dump data for the firmware provided 154 * dump sections. 155 * For each dump section type supported, a 32bit cell which defines 156 * the ID of a supported section followed by two 32 bit cells which 157 * gives teh size of the section in bytes. 158 */ 159 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 160 &size); 161 162 if (!sections) 163 return 1; 164 165 num_sections = size / (3 * sizeof(u32)); 166 167 for (i = 0; i < num_sections; i++, sections += 3) { 168 u32 type = (u32)of_read_number(sections, 1); 169 170 switch (type) { 171 case FADUMP_CPU_STATE_DATA: 172 fw_dump.cpu_state_data_size = 173 of_read_ulong(§ions[1], 2); 174 break; 175 case FADUMP_HPTE_REGION: 176 fw_dump.hpte_region_size = 177 of_read_ulong(§ions[1], 2); 178 break; 179 } 180 } 181 182 return 1; 183 } 184 185 /* 186 * If fadump is registered, check if the memory provided 187 * falls within boot memory area and reserved memory area. 188 */ 189 int is_fadump_memory_area(u64 addr, ulong size) 190 { 191 u64 d_start = fw_dump.reserve_dump_area_start; 192 u64 d_end = d_start + fw_dump.reserve_dump_area_size; 193 194 if (!fw_dump.dump_registered) 195 return 0; 196 197 if (((addr + size) > d_start) && (addr <= d_end)) 198 return 1; 199 200 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; 201 } 202 203 int should_fadump_crash(void) 204 { 205 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 206 return 0; 207 return 1; 208 } 209 210 int is_fadump_active(void) 211 { 212 return fw_dump.dump_active; 213 } 214 215 /* 216 * Returns 1, if there are no holes in boot memory area, 217 * 0 otherwise. 218 */ 219 static int is_boot_memory_area_contiguous(void) 220 { 221 struct memblock_region *reg; 222 unsigned long tstart, tend; 223 unsigned long start_pfn = PHYS_PFN(RMA_START); 224 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size); 225 unsigned int ret = 0; 226 227 for_each_memblock(memory, reg) { 228 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 229 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 230 if (tstart < tend) { 231 /* Memory hole from start_pfn to tstart */ 232 if (tstart > start_pfn) 233 break; 234 235 if (tend == end_pfn) { 236 ret = 1; 237 break; 238 } 239 240 start_pfn = tend + 1; 241 } 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 static bool is_reserved_memory_area_contiguous(void) 252 { 253 struct memblock_region *reg; 254 unsigned long start, end; 255 unsigned long d_start = fw_dump.reserve_dump_area_start; 256 unsigned long d_end = d_start + fw_dump.reserve_dump_area_size; 257 258 for_each_memblock(memory, reg) { 259 start = max(d_start, (unsigned long)reg->base); 260 end = min(d_end, (unsigned long)(reg->base + reg->size)); 261 if (d_start < end) { 262 /* Memory hole from d_start to start */ 263 if (start > d_start) 264 break; 265 266 if (end == d_end) 267 return true; 268 269 d_start = end + 1; 270 } 271 } 272 273 return false; 274 } 275 276 /* Print firmware assisted dump configurations for debugging purpose. */ 277 static void fadump_show_config(void) 278 { 279 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 280 (fw_dump.fadump_supported ? "present" : "no support")); 281 282 if (!fw_dump.fadump_supported) 283 return; 284 285 pr_debug("Fadump enabled : %s\n", 286 (fw_dump.fadump_enabled ? "yes" : "no")); 287 pr_debug("Dump Active : %s\n", 288 (fw_dump.dump_active ? "yes" : "no")); 289 pr_debug("Dump section sizes:\n"); 290 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 291 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 292 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 293 } 294 295 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 296 unsigned long addr) 297 { 298 if (!fdm) 299 return 0; 300 301 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 302 addr = addr & PAGE_MASK; 303 304 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 305 fdm->header.dump_num_sections = cpu_to_be16(3); 306 fdm->header.dump_status_flag = 0; 307 fdm->header.offset_first_dump_section = 308 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 309 310 /* 311 * Fields for disk dump option. 312 * We are not using disk dump option, hence set these fields to 0. 313 */ 314 fdm->header.dd_block_size = 0; 315 fdm->header.dd_block_offset = 0; 316 fdm->header.dd_num_blocks = 0; 317 fdm->header.dd_offset_disk_path = 0; 318 319 /* set 0 to disable an automatic dump-reboot. */ 320 fdm->header.max_time_auto = 0; 321 322 /* Kernel dump sections */ 323 /* cpu state data section. */ 324 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 325 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 326 fdm->cpu_state_data.source_address = 0; 327 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 328 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 329 addr += fw_dump.cpu_state_data_size; 330 331 /* hpte region section */ 332 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 333 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 334 fdm->hpte_region.source_address = 0; 335 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 336 fdm->hpte_region.destination_address = cpu_to_be64(addr); 337 addr += fw_dump.hpte_region_size; 338 339 /* RMA region section */ 340 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 341 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 342 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 343 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 344 fdm->rmr_region.destination_address = cpu_to_be64(addr); 345 addr += fw_dump.boot_memory_size; 346 347 return addr; 348 } 349 350 /** 351 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 352 * 353 * Function to find the largest memory size we need to reserve during early 354 * boot process. This will be the size of the memory that is required for a 355 * kernel to boot successfully. 356 * 357 * This function has been taken from phyp-assisted dump feature implementation. 358 * 359 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 360 * 361 * TODO: Come up with better approach to find out more accurate memory size 362 * that is required for a kernel to boot successfully. 363 * 364 */ 365 static inline unsigned long fadump_calculate_reserve_size(void) 366 { 367 int ret; 368 unsigned long long base, size; 369 370 if (fw_dump.reserve_bootvar) 371 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 372 373 /* 374 * Check if the size is specified through crashkernel= cmdline 375 * option. If yes, then use that but ignore base as fadump reserves 376 * memory at a predefined offset. 377 */ 378 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 379 &size, &base); 380 if (ret == 0 && size > 0) { 381 unsigned long max_size; 382 383 if (fw_dump.reserve_bootvar) 384 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 385 386 fw_dump.reserve_bootvar = (unsigned long)size; 387 388 /* 389 * Adjust if the boot memory size specified is above 390 * the upper limit. 391 */ 392 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 393 if (fw_dump.reserve_bootvar > max_size) { 394 fw_dump.reserve_bootvar = max_size; 395 pr_info("Adjusted boot memory size to %luMB\n", 396 (fw_dump.reserve_bootvar >> 20)); 397 } 398 399 return fw_dump.reserve_bootvar; 400 } else if (fw_dump.reserve_bootvar) { 401 /* 402 * 'fadump_reserve_mem=' is being used to reserve memory 403 * for firmware-assisted dump. 404 */ 405 return fw_dump.reserve_bootvar; 406 } 407 408 /* divide by 20 to get 5% of value */ 409 size = memblock_phys_mem_size() / 20; 410 411 /* round it down in multiples of 256 */ 412 size = size & ~0x0FFFFFFFUL; 413 414 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 415 if (memory_limit && size > memory_limit) 416 size = memory_limit; 417 418 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 419 } 420 421 /* 422 * Calculate the total memory size required to be reserved for 423 * firmware-assisted dump registration. 424 */ 425 static unsigned long get_fadump_area_size(void) 426 { 427 unsigned long size = 0; 428 429 size += fw_dump.cpu_state_data_size; 430 size += fw_dump.hpte_region_size; 431 size += fw_dump.boot_memory_size; 432 size += sizeof(struct fadump_crash_info_header); 433 size += sizeof(struct elfhdr); /* ELF core header.*/ 434 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 435 /* Program headers for crash memory regions. */ 436 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 437 438 size = PAGE_ALIGN(size); 439 return size; 440 } 441 442 static void __init fadump_reserve_crash_area(unsigned long base, 443 unsigned long size) 444 { 445 struct memblock_region *reg; 446 unsigned long mstart, mend, msize; 447 448 for_each_memblock(memory, reg) { 449 mstart = max_t(unsigned long, base, reg->base); 450 mend = reg->base + reg->size; 451 mend = min(base + size, mend); 452 453 if (mstart < mend) { 454 msize = mend - mstart; 455 memblock_reserve(mstart, msize); 456 pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n", 457 (msize >> 20), mstart); 458 } 459 } 460 } 461 462 int __init fadump_reserve_mem(void) 463 { 464 unsigned long base, size, memory_boundary; 465 466 if (!fw_dump.fadump_enabled) 467 return 0; 468 469 if (!fw_dump.fadump_supported) { 470 printk(KERN_INFO "Firmware-assisted dump is not supported on" 471 " this hardware\n"); 472 fw_dump.fadump_enabled = 0; 473 return 0; 474 } 475 /* 476 * Initialize boot memory size 477 * If dump is active then we have already calculated the size during 478 * first kernel. 479 */ 480 if (fdm_active) 481 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 482 else { 483 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 484 #ifdef CONFIG_CMA 485 if (!fw_dump.nocma) 486 fw_dump.boot_memory_size = 487 ALIGN(fw_dump.boot_memory_size, 488 FADUMP_CMA_ALIGNMENT); 489 #endif 490 } 491 492 /* 493 * Calculate the memory boundary. 494 * If memory_limit is less than actual memory boundary then reserve 495 * the memory for fadump beyond the memory_limit and adjust the 496 * memory_limit accordingly, so that the running kernel can run with 497 * specified memory_limit. 498 */ 499 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 500 size = get_fadump_area_size(); 501 if ((memory_limit + size) < memblock_end_of_DRAM()) 502 memory_limit += size; 503 else 504 memory_limit = memblock_end_of_DRAM(); 505 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 506 " dump, now %#016llx\n", memory_limit); 507 } 508 if (memory_limit) 509 memory_boundary = memory_limit; 510 else 511 memory_boundary = memblock_end_of_DRAM(); 512 513 if (fw_dump.dump_active) { 514 pr_info("Firmware-assisted dump is active.\n"); 515 516 #ifdef CONFIG_HUGETLB_PAGE 517 /* 518 * FADump capture kernel doesn't care much about hugepages. 519 * In fact, handling hugepages in capture kernel is asking for 520 * trouble. So, disable HugeTLB support when fadump is active. 521 */ 522 hugetlb_disabled = true; 523 #endif 524 /* 525 * If last boot has crashed then reserve all the memory 526 * above boot_memory_size so that we don't touch it until 527 * dump is written to disk by userspace tool. This memory 528 * will be released for general use once the dump is saved. 529 */ 530 base = fw_dump.boot_memory_size; 531 size = memory_boundary - base; 532 fadump_reserve_crash_area(base, size); 533 534 fw_dump.fadumphdr_addr = 535 be64_to_cpu(fdm_active->rmr_region.destination_address) + 536 be64_to_cpu(fdm_active->rmr_region.source_len); 537 pr_debug("fadumphdr_addr = %pa\n", &fw_dump.fadumphdr_addr); 538 fw_dump.reserve_dump_area_start = base; 539 fw_dump.reserve_dump_area_size = size; 540 } else { 541 size = get_fadump_area_size(); 542 543 /* 544 * Reserve memory at an offset closer to bottom of the RAM to 545 * minimize the impact of memory hot-remove operation. We can't 546 * use memblock_find_in_range() here since it doesn't allocate 547 * from bottom to top. 548 */ 549 for (base = fw_dump.boot_memory_size; 550 base <= (memory_boundary - size); 551 base += size) { 552 if (memblock_is_region_memory(base, size) && 553 !memblock_is_region_reserved(base, size)) 554 break; 555 } 556 if ((base > (memory_boundary - size)) || 557 memblock_reserve(base, size)) { 558 pr_err("Failed to reserve memory\n"); 559 return 0; 560 } 561 562 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 563 "assisted dump (System RAM: %ldMB)\n", 564 (unsigned long)(size >> 20), 565 (unsigned long)(base >> 20), 566 (unsigned long)(memblock_phys_mem_size() >> 20)); 567 568 fw_dump.reserve_dump_area_start = base; 569 fw_dump.reserve_dump_area_size = size; 570 return fadump_cma_init(); 571 } 572 return 1; 573 } 574 575 unsigned long __init arch_reserved_kernel_pages(void) 576 { 577 return memblock_reserved_size() / PAGE_SIZE; 578 } 579 580 /* Look for fadump= cmdline option. */ 581 static int __init early_fadump_param(char *p) 582 { 583 if (!p) 584 return 1; 585 586 if (strncmp(p, "on", 2) == 0) 587 fw_dump.fadump_enabled = 1; 588 else if (strncmp(p, "off", 3) == 0) 589 fw_dump.fadump_enabled = 0; 590 else if (strncmp(p, "nocma", 5) == 0) { 591 fw_dump.fadump_enabled = 1; 592 fw_dump.nocma = 1; 593 } 594 595 return 0; 596 } 597 early_param("fadump", early_fadump_param); 598 599 /* 600 * Look for fadump_reserve_mem= cmdline option 601 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 602 * the sooner 'crashkernel=' parameter is accustomed to. 603 */ 604 static int __init early_fadump_reserve_mem(char *p) 605 { 606 if (p) 607 fw_dump.reserve_bootvar = memparse(p, &p); 608 return 0; 609 } 610 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 611 612 static int register_fw_dump(struct fadump_mem_struct *fdm) 613 { 614 int rc, err; 615 unsigned int wait_time; 616 617 pr_debug("Registering for firmware-assisted kernel dump...\n"); 618 619 /* TODO: Add upper time limit for the delay */ 620 do { 621 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 622 FADUMP_REGISTER, fdm, 623 sizeof(struct fadump_mem_struct)); 624 625 wait_time = rtas_busy_delay_time(rc); 626 if (wait_time) 627 mdelay(wait_time); 628 629 } while (wait_time); 630 631 err = -EIO; 632 switch (rc) { 633 default: 634 pr_err("Failed to register. Unknown Error(%d).\n", rc); 635 break; 636 case -1: 637 printk(KERN_ERR "Failed to register firmware-assisted kernel" 638 " dump. Hardware Error(%d).\n", rc); 639 break; 640 case -3: 641 if (!is_boot_memory_area_contiguous()) 642 pr_err("Can't have holes in boot memory area while registering fadump\n"); 643 else if (!is_reserved_memory_area_contiguous()) 644 pr_err("Can't have holes in reserved memory area while" 645 " registering fadump\n"); 646 647 printk(KERN_ERR "Failed to register firmware-assisted kernel" 648 " dump. Parameter Error(%d).\n", rc); 649 err = -EINVAL; 650 break; 651 case -9: 652 printk(KERN_ERR "firmware-assisted kernel dump is already " 653 " registered."); 654 fw_dump.dump_registered = 1; 655 err = -EEXIST; 656 break; 657 case 0: 658 printk(KERN_INFO "firmware-assisted kernel dump registration" 659 " is successful\n"); 660 fw_dump.dump_registered = 1; 661 err = 0; 662 break; 663 } 664 return err; 665 } 666 667 void crash_fadump(struct pt_regs *regs, const char *str) 668 { 669 struct fadump_crash_info_header *fdh = NULL; 670 int old_cpu, this_cpu; 671 672 if (!should_fadump_crash()) 673 return; 674 675 /* 676 * old_cpu == -1 means this is the first CPU which has come here, 677 * go ahead and trigger fadump. 678 * 679 * old_cpu != -1 means some other CPU has already on it's way 680 * to trigger fadump, just keep looping here. 681 */ 682 this_cpu = smp_processor_id(); 683 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 684 685 if (old_cpu != -1) { 686 /* 687 * We can't loop here indefinitely. Wait as long as fadump 688 * is in force. If we race with fadump un-registration this 689 * loop will break and then we go down to normal panic path 690 * and reboot. If fadump is in force the first crashing 691 * cpu will definitely trigger fadump. 692 */ 693 while (fw_dump.dump_registered) 694 cpu_relax(); 695 return; 696 } 697 698 fdh = __va(fw_dump.fadumphdr_addr); 699 fdh->crashing_cpu = crashing_cpu; 700 crash_save_vmcoreinfo(); 701 702 if (regs) 703 fdh->regs = *regs; 704 else 705 ppc_save_regs(&fdh->regs); 706 707 fdh->online_mask = *cpu_online_mask; 708 709 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 710 rtas_os_term((char *)str); 711 } 712 713 #define GPR_MASK 0xffffff0000000000 714 static inline int fadump_gpr_index(u64 id) 715 { 716 int i = -1; 717 char str[3]; 718 719 if ((id & GPR_MASK) == REG_ID("GPR")) { 720 /* get the digits at the end */ 721 id &= ~GPR_MASK; 722 id >>= 24; 723 str[2] = '\0'; 724 str[1] = id & 0xff; 725 str[0] = (id >> 8) & 0xff; 726 sscanf(str, "%d", &i); 727 if (i > 31) 728 i = -1; 729 } 730 return i; 731 } 732 733 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 734 u64 reg_val) 735 { 736 int i; 737 738 i = fadump_gpr_index(reg_id); 739 if (i >= 0) 740 regs->gpr[i] = (unsigned long)reg_val; 741 else if (reg_id == REG_ID("NIA")) 742 regs->nip = (unsigned long)reg_val; 743 else if (reg_id == REG_ID("MSR")) 744 regs->msr = (unsigned long)reg_val; 745 else if (reg_id == REG_ID("CTR")) 746 regs->ctr = (unsigned long)reg_val; 747 else if (reg_id == REG_ID("LR")) 748 regs->link = (unsigned long)reg_val; 749 else if (reg_id == REG_ID("XER")) 750 regs->xer = (unsigned long)reg_val; 751 else if (reg_id == REG_ID("CR")) 752 regs->ccr = (unsigned long)reg_val; 753 else if (reg_id == REG_ID("DAR")) 754 regs->dar = (unsigned long)reg_val; 755 else if (reg_id == REG_ID("DSISR")) 756 regs->dsisr = (unsigned long)reg_val; 757 } 758 759 static struct fadump_reg_entry* 760 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 761 { 762 memset(regs, 0, sizeof(struct pt_regs)); 763 764 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 765 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 766 be64_to_cpu(reg_entry->reg_value)); 767 reg_entry++; 768 } 769 reg_entry++; 770 return reg_entry; 771 } 772 773 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 774 { 775 struct elf_prstatus prstatus; 776 777 memset(&prstatus, 0, sizeof(prstatus)); 778 /* 779 * FIXME: How do i get PID? Do I really need it? 780 * prstatus.pr_pid = ???? 781 */ 782 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 783 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 784 &prstatus, sizeof(prstatus)); 785 return buf; 786 } 787 788 static void fadump_update_elfcore_header(char *bufp) 789 { 790 struct elfhdr *elf; 791 struct elf_phdr *phdr; 792 793 elf = (struct elfhdr *)bufp; 794 bufp += sizeof(struct elfhdr); 795 796 /* First note is a place holder for cpu notes info. */ 797 phdr = (struct elf_phdr *)bufp; 798 799 if (phdr->p_type == PT_NOTE) { 800 phdr->p_paddr = fw_dump.cpu_notes_buf; 801 phdr->p_offset = phdr->p_paddr; 802 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 803 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 804 } 805 return; 806 } 807 808 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 809 { 810 void *vaddr; 811 struct page *page; 812 unsigned long order, count, i; 813 814 order = get_order(size); 815 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 816 if (!vaddr) 817 return NULL; 818 819 count = 1 << order; 820 page = virt_to_page(vaddr); 821 for (i = 0; i < count; i++) 822 SetPageReserved(page + i); 823 return vaddr; 824 } 825 826 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 827 { 828 struct page *page; 829 unsigned long order, count, i; 830 831 order = get_order(size); 832 count = 1 << order; 833 page = virt_to_page(vaddr); 834 for (i = 0; i < count; i++) 835 ClearPageReserved(page + i); 836 __free_pages(page, order); 837 } 838 839 /* 840 * Read CPU state dump data and convert it into ELF notes. 841 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 842 * used to access the data to allow for additional fields to be added without 843 * affecting compatibility. Each list of registers for a CPU starts with 844 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 845 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 846 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 847 * of register value. For more details refer to PAPR document. 848 * 849 * Only for the crashing cpu we ignore the CPU dump data and get exact 850 * state from fadump crash info structure populated by first kernel at the 851 * time of crash. 852 */ 853 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 854 { 855 struct fadump_reg_save_area_header *reg_header; 856 struct fadump_reg_entry *reg_entry; 857 struct fadump_crash_info_header *fdh = NULL; 858 void *vaddr; 859 unsigned long addr; 860 u32 num_cpus, *note_buf; 861 struct pt_regs regs; 862 int i, rc = 0, cpu = 0; 863 864 if (!fdm->cpu_state_data.bytes_dumped) 865 return -EINVAL; 866 867 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 868 vaddr = __va(addr); 869 870 reg_header = vaddr; 871 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 872 printk(KERN_ERR "Unable to read register save area.\n"); 873 return -ENOENT; 874 } 875 pr_debug("--------CPU State Data------------\n"); 876 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 877 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 878 879 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 880 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 881 pr_debug("NumCpus : %u\n", num_cpus); 882 vaddr += sizeof(u32); 883 reg_entry = (struct fadump_reg_entry *)vaddr; 884 885 /* Allocate buffer to hold cpu crash notes. */ 886 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 887 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 888 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 889 if (!note_buf) { 890 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 891 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 892 return -ENOMEM; 893 } 894 fw_dump.cpu_notes_buf = __pa(note_buf); 895 896 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 897 (num_cpus * sizeof(note_buf_t)), note_buf); 898 899 if (fw_dump.fadumphdr_addr) 900 fdh = __va(fw_dump.fadumphdr_addr); 901 902 for (i = 0; i < num_cpus; i++) { 903 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 904 printk(KERN_ERR "Unable to read CPU state data\n"); 905 rc = -ENOENT; 906 goto error_out; 907 } 908 /* Lower 4 bytes of reg_value contains logical cpu id */ 909 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 910 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 911 SKIP_TO_NEXT_CPU(reg_entry); 912 continue; 913 } 914 pr_debug("Reading register data for cpu %d...\n", cpu); 915 if (fdh && fdh->crashing_cpu == cpu) { 916 regs = fdh->regs; 917 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 918 SKIP_TO_NEXT_CPU(reg_entry); 919 } else { 920 reg_entry++; 921 reg_entry = fadump_read_registers(reg_entry, ®s); 922 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 923 } 924 } 925 final_note(note_buf); 926 927 if (fdh) { 928 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 929 fdh->elfcorehdr_addr); 930 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 931 } 932 return 0; 933 934 error_out: 935 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 936 fw_dump.cpu_notes_buf_size); 937 fw_dump.cpu_notes_buf = 0; 938 fw_dump.cpu_notes_buf_size = 0; 939 return rc; 940 941 } 942 943 /* 944 * Validate and process the dump data stored by firmware before exporting 945 * it through '/proc/vmcore'. 946 */ 947 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 948 { 949 struct fadump_crash_info_header *fdh; 950 int rc = 0; 951 952 if (!fdm_active || !fw_dump.fadumphdr_addr) 953 return -EINVAL; 954 955 /* Check if the dump data is valid. */ 956 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 957 (fdm_active->cpu_state_data.error_flags != 0) || 958 (fdm_active->rmr_region.error_flags != 0)) { 959 printk(KERN_ERR "Dump taken by platform is not valid\n"); 960 return -EINVAL; 961 } 962 if ((fdm_active->rmr_region.bytes_dumped != 963 fdm_active->rmr_region.source_len) || 964 !fdm_active->cpu_state_data.bytes_dumped) { 965 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 966 return -EINVAL; 967 } 968 969 /* Validate the fadump crash info header */ 970 fdh = __va(fw_dump.fadumphdr_addr); 971 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 972 printk(KERN_ERR "Crash info header is not valid.\n"); 973 return -EINVAL; 974 } 975 976 rc = fadump_build_cpu_notes(fdm_active); 977 if (rc) 978 return rc; 979 980 /* 981 * We are done validating dump info and elfcore header is now ready 982 * to be exported. set elfcorehdr_addr so that vmcore module will 983 * export the elfcore header through '/proc/vmcore'. 984 */ 985 elfcorehdr_addr = fdh->elfcorehdr_addr; 986 987 return 0; 988 } 989 990 static void free_crash_memory_ranges(void) 991 { 992 kfree(crash_memory_ranges); 993 crash_memory_ranges = NULL; 994 crash_memory_ranges_size = 0; 995 max_crash_mem_ranges = 0; 996 } 997 998 /* 999 * Allocate or reallocate crash memory ranges array in incremental units 1000 * of PAGE_SIZE. 1001 */ 1002 static int allocate_crash_memory_ranges(void) 1003 { 1004 struct fad_crash_memory_ranges *new_array; 1005 u64 new_size; 1006 1007 new_size = crash_memory_ranges_size + PAGE_SIZE; 1008 pr_debug("Allocating %llu bytes of memory for crash memory ranges\n", 1009 new_size); 1010 1011 new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL); 1012 if (new_array == NULL) { 1013 pr_err("Insufficient memory for setting up crash memory ranges\n"); 1014 free_crash_memory_ranges(); 1015 return -ENOMEM; 1016 } 1017 1018 crash_memory_ranges = new_array; 1019 crash_memory_ranges_size = new_size; 1020 max_crash_mem_ranges = (new_size / 1021 sizeof(struct fad_crash_memory_ranges)); 1022 return 0; 1023 } 1024 1025 static inline int fadump_add_crash_memory(unsigned long long base, 1026 unsigned long long end) 1027 { 1028 u64 start, size; 1029 bool is_adjacent = false; 1030 1031 if (base == end) 1032 return 0; 1033 1034 /* 1035 * Fold adjacent memory ranges to bring down the memory ranges/ 1036 * PT_LOAD segments count. 1037 */ 1038 if (crash_mem_ranges) { 1039 start = crash_memory_ranges[crash_mem_ranges - 1].base; 1040 size = crash_memory_ranges[crash_mem_ranges - 1].size; 1041 1042 if ((start + size) == base) 1043 is_adjacent = true; 1044 } 1045 if (!is_adjacent) { 1046 /* resize the array on reaching the limit */ 1047 if (crash_mem_ranges == max_crash_mem_ranges) { 1048 int ret; 1049 1050 ret = allocate_crash_memory_ranges(); 1051 if (ret) 1052 return ret; 1053 } 1054 1055 start = base; 1056 crash_memory_ranges[crash_mem_ranges].base = start; 1057 crash_mem_ranges++; 1058 } 1059 1060 crash_memory_ranges[crash_mem_ranges - 1].size = (end - start); 1061 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 1062 (crash_mem_ranges - 1), start, end - 1, (end - start)); 1063 return 0; 1064 } 1065 1066 static int fadump_exclude_reserved_area(unsigned long long start, 1067 unsigned long long end) 1068 { 1069 unsigned long long ra_start, ra_end; 1070 int ret = 0; 1071 1072 ra_start = fw_dump.reserve_dump_area_start; 1073 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1074 1075 if ((ra_start < end) && (ra_end > start)) { 1076 if ((start < ra_start) && (end > ra_end)) { 1077 ret = fadump_add_crash_memory(start, ra_start); 1078 if (ret) 1079 return ret; 1080 1081 ret = fadump_add_crash_memory(ra_end, end); 1082 } else if (start < ra_start) { 1083 ret = fadump_add_crash_memory(start, ra_start); 1084 } else if (ra_end < end) { 1085 ret = fadump_add_crash_memory(ra_end, end); 1086 } 1087 } else 1088 ret = fadump_add_crash_memory(start, end); 1089 1090 return ret; 1091 } 1092 1093 static int fadump_init_elfcore_header(char *bufp) 1094 { 1095 struct elfhdr *elf; 1096 1097 elf = (struct elfhdr *) bufp; 1098 bufp += sizeof(struct elfhdr); 1099 memcpy(elf->e_ident, ELFMAG, SELFMAG); 1100 elf->e_ident[EI_CLASS] = ELF_CLASS; 1101 elf->e_ident[EI_DATA] = ELF_DATA; 1102 elf->e_ident[EI_VERSION] = EV_CURRENT; 1103 elf->e_ident[EI_OSABI] = ELF_OSABI; 1104 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 1105 elf->e_type = ET_CORE; 1106 elf->e_machine = ELF_ARCH; 1107 elf->e_version = EV_CURRENT; 1108 elf->e_entry = 0; 1109 elf->e_phoff = sizeof(struct elfhdr); 1110 elf->e_shoff = 0; 1111 #if defined(_CALL_ELF) 1112 elf->e_flags = _CALL_ELF; 1113 #else 1114 elf->e_flags = 0; 1115 #endif 1116 elf->e_ehsize = sizeof(struct elfhdr); 1117 elf->e_phentsize = sizeof(struct elf_phdr); 1118 elf->e_phnum = 0; 1119 elf->e_shentsize = 0; 1120 elf->e_shnum = 0; 1121 elf->e_shstrndx = 0; 1122 1123 return 0; 1124 } 1125 1126 /* 1127 * Traverse through memblock structure and setup crash memory ranges. These 1128 * ranges will be used create PT_LOAD program headers in elfcore header. 1129 */ 1130 static int fadump_setup_crash_memory_ranges(void) 1131 { 1132 struct memblock_region *reg; 1133 unsigned long long start, end; 1134 int ret; 1135 1136 pr_debug("Setup crash memory ranges.\n"); 1137 crash_mem_ranges = 0; 1138 1139 /* 1140 * add the first memory chunk (RMA_START through boot_memory_size) as 1141 * a separate memory chunk. The reason is, at the time crash firmware 1142 * will move the content of this memory chunk to different location 1143 * specified during fadump registration. We need to create a separate 1144 * program header for this chunk with the correct offset. 1145 */ 1146 ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 1147 if (ret) 1148 return ret; 1149 1150 for_each_memblock(memory, reg) { 1151 start = (unsigned long long)reg->base; 1152 end = start + (unsigned long long)reg->size; 1153 1154 /* 1155 * skip the first memory chunk that is already added (RMA_START 1156 * through boot_memory_size). This logic needs a relook if and 1157 * when RMA_START changes to a non-zero value. 1158 */ 1159 BUILD_BUG_ON(RMA_START != 0); 1160 if (start < fw_dump.boot_memory_size) { 1161 if (end > fw_dump.boot_memory_size) 1162 start = fw_dump.boot_memory_size; 1163 else 1164 continue; 1165 } 1166 1167 /* add this range excluding the reserved dump area. */ 1168 ret = fadump_exclude_reserved_area(start, end); 1169 if (ret) 1170 return ret; 1171 } 1172 1173 return 0; 1174 } 1175 1176 /* 1177 * If the given physical address falls within the boot memory region then 1178 * return the relocated address that points to the dump region reserved 1179 * for saving initial boot memory contents. 1180 */ 1181 static inline unsigned long fadump_relocate(unsigned long paddr) 1182 { 1183 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 1184 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 1185 else 1186 return paddr; 1187 } 1188 1189 static int fadump_create_elfcore_headers(char *bufp) 1190 { 1191 struct elfhdr *elf; 1192 struct elf_phdr *phdr; 1193 int i; 1194 1195 fadump_init_elfcore_header(bufp); 1196 elf = (struct elfhdr *)bufp; 1197 bufp += sizeof(struct elfhdr); 1198 1199 /* 1200 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1201 * will be populated during second kernel boot after crash. Hence 1202 * this PT_NOTE will always be the first elf note. 1203 * 1204 * NOTE: Any new ELF note addition should be placed after this note. 1205 */ 1206 phdr = (struct elf_phdr *)bufp; 1207 bufp += sizeof(struct elf_phdr); 1208 phdr->p_type = PT_NOTE; 1209 phdr->p_flags = 0; 1210 phdr->p_vaddr = 0; 1211 phdr->p_align = 0; 1212 1213 phdr->p_offset = 0; 1214 phdr->p_paddr = 0; 1215 phdr->p_filesz = 0; 1216 phdr->p_memsz = 0; 1217 1218 (elf->e_phnum)++; 1219 1220 /* setup ELF PT_NOTE for vmcoreinfo */ 1221 phdr = (struct elf_phdr *)bufp; 1222 bufp += sizeof(struct elf_phdr); 1223 phdr->p_type = PT_NOTE; 1224 phdr->p_flags = 0; 1225 phdr->p_vaddr = 0; 1226 phdr->p_align = 0; 1227 1228 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1229 phdr->p_offset = phdr->p_paddr; 1230 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1231 1232 /* Increment number of program headers. */ 1233 (elf->e_phnum)++; 1234 1235 /* setup PT_LOAD sections. */ 1236 1237 for (i = 0; i < crash_mem_ranges; i++) { 1238 unsigned long long mbase, msize; 1239 mbase = crash_memory_ranges[i].base; 1240 msize = crash_memory_ranges[i].size; 1241 1242 if (!msize) 1243 continue; 1244 1245 phdr = (struct elf_phdr *)bufp; 1246 bufp += sizeof(struct elf_phdr); 1247 phdr->p_type = PT_LOAD; 1248 phdr->p_flags = PF_R|PF_W|PF_X; 1249 phdr->p_offset = mbase; 1250 1251 if (mbase == RMA_START) { 1252 /* 1253 * The entire RMA region will be moved by firmware 1254 * to the specified destination_address. Hence set 1255 * the correct offset. 1256 */ 1257 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1258 } 1259 1260 phdr->p_paddr = mbase; 1261 phdr->p_vaddr = (unsigned long)__va(mbase); 1262 phdr->p_filesz = msize; 1263 phdr->p_memsz = msize; 1264 phdr->p_align = 0; 1265 1266 /* Increment number of program headers. */ 1267 (elf->e_phnum)++; 1268 } 1269 return 0; 1270 } 1271 1272 static unsigned long init_fadump_header(unsigned long addr) 1273 { 1274 struct fadump_crash_info_header *fdh; 1275 1276 if (!addr) 1277 return 0; 1278 1279 fw_dump.fadumphdr_addr = addr; 1280 fdh = __va(addr); 1281 addr += sizeof(struct fadump_crash_info_header); 1282 1283 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1284 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1285 fdh->elfcorehdr_addr = addr; 1286 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1287 fdh->crashing_cpu = CPU_UNKNOWN; 1288 1289 return addr; 1290 } 1291 1292 static int register_fadump(void) 1293 { 1294 unsigned long addr; 1295 void *vaddr; 1296 int ret; 1297 1298 /* 1299 * If no memory is reserved then we can not register for firmware- 1300 * assisted dump. 1301 */ 1302 if (!fw_dump.reserve_dump_area_size) 1303 return -ENODEV; 1304 1305 ret = fadump_setup_crash_memory_ranges(); 1306 if (ret) 1307 return ret; 1308 1309 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1310 /* Initialize fadump crash info header. */ 1311 addr = init_fadump_header(addr); 1312 vaddr = __va(addr); 1313 1314 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1315 fadump_create_elfcore_headers(vaddr); 1316 1317 /* register the future kernel dump with firmware. */ 1318 return register_fw_dump(&fdm); 1319 } 1320 1321 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1322 { 1323 int rc = 0; 1324 unsigned int wait_time; 1325 1326 pr_debug("Un-register firmware-assisted dump\n"); 1327 1328 /* TODO: Add upper time limit for the delay */ 1329 do { 1330 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1331 FADUMP_UNREGISTER, fdm, 1332 sizeof(struct fadump_mem_struct)); 1333 1334 wait_time = rtas_busy_delay_time(rc); 1335 if (wait_time) 1336 mdelay(wait_time); 1337 } while (wait_time); 1338 1339 if (rc) { 1340 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1341 " unexpected error(%d).\n", rc); 1342 return rc; 1343 } 1344 fw_dump.dump_registered = 0; 1345 return 0; 1346 } 1347 1348 static int fadump_invalidate_dump(const struct fadump_mem_struct *fdm) 1349 { 1350 int rc = 0; 1351 unsigned int wait_time; 1352 1353 pr_debug("Invalidating firmware-assisted dump registration\n"); 1354 1355 /* TODO: Add upper time limit for the delay */ 1356 do { 1357 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1358 FADUMP_INVALIDATE, fdm, 1359 sizeof(struct fadump_mem_struct)); 1360 1361 wait_time = rtas_busy_delay_time(rc); 1362 if (wait_time) 1363 mdelay(wait_time); 1364 } while (wait_time); 1365 1366 if (rc) { 1367 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1368 return rc; 1369 } 1370 fw_dump.dump_active = 0; 1371 fdm_active = NULL; 1372 return 0; 1373 } 1374 1375 void fadump_cleanup(void) 1376 { 1377 /* Invalidate the registration only if dump is active. */ 1378 if (fw_dump.dump_active) { 1379 /* pass the same memory dump structure provided by platform */ 1380 fadump_invalidate_dump(fdm_active); 1381 } else if (fw_dump.dump_registered) { 1382 /* Un-register Firmware-assisted dump if it was registered. */ 1383 fadump_unregister_dump(&fdm); 1384 free_crash_memory_ranges(); 1385 } 1386 } 1387 1388 static void fadump_free_reserved_memory(unsigned long start_pfn, 1389 unsigned long end_pfn) 1390 { 1391 unsigned long pfn; 1392 unsigned long time_limit = jiffies + HZ; 1393 1394 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1395 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1396 1397 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1398 free_reserved_page(pfn_to_page(pfn)); 1399 1400 if (time_after(jiffies, time_limit)) { 1401 cond_resched(); 1402 time_limit = jiffies + HZ; 1403 } 1404 } 1405 } 1406 1407 /* 1408 * Skip memory holes and free memory that was actually reserved. 1409 */ 1410 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1411 { 1412 struct memblock_region *reg; 1413 unsigned long tstart, tend; 1414 unsigned long start_pfn = PHYS_PFN(start); 1415 unsigned long end_pfn = PHYS_PFN(end); 1416 1417 for_each_memblock(memory, reg) { 1418 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1419 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1420 if (tstart < tend) { 1421 fadump_free_reserved_memory(tstart, tend); 1422 1423 if (tend == end_pfn) 1424 break; 1425 1426 start_pfn = tend + 1; 1427 } 1428 } 1429 } 1430 1431 /* 1432 * Release the memory that was reserved in early boot to preserve the memory 1433 * contents. The released memory will be available for general use. 1434 */ 1435 static void fadump_release_memory(unsigned long begin, unsigned long end) 1436 { 1437 unsigned long ra_start, ra_end; 1438 1439 ra_start = fw_dump.reserve_dump_area_start; 1440 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1441 1442 /* 1443 * exclude the dump reserve area. Will reuse it for next 1444 * fadump registration. 1445 */ 1446 if (begin < ra_end && end > ra_start) { 1447 if (begin < ra_start) 1448 fadump_release_reserved_area(begin, ra_start); 1449 if (end > ra_end) 1450 fadump_release_reserved_area(ra_end, end); 1451 } else 1452 fadump_release_reserved_area(begin, end); 1453 } 1454 1455 static void fadump_invalidate_release_mem(void) 1456 { 1457 unsigned long reserved_area_start, reserved_area_end; 1458 unsigned long destination_address; 1459 1460 mutex_lock(&fadump_mutex); 1461 if (!fw_dump.dump_active) { 1462 mutex_unlock(&fadump_mutex); 1463 return; 1464 } 1465 1466 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1467 fadump_cleanup(); 1468 mutex_unlock(&fadump_mutex); 1469 1470 /* 1471 * Save the current reserved memory bounds we will require them 1472 * later for releasing the memory for general use. 1473 */ 1474 reserved_area_start = fw_dump.reserve_dump_area_start; 1475 reserved_area_end = reserved_area_start + 1476 fw_dump.reserve_dump_area_size; 1477 /* 1478 * Setup reserve_dump_area_start and its size so that we can 1479 * reuse this reserved memory for Re-registration. 1480 */ 1481 fw_dump.reserve_dump_area_start = destination_address; 1482 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1483 1484 fadump_release_memory(reserved_area_start, reserved_area_end); 1485 if (fw_dump.cpu_notes_buf) { 1486 fadump_cpu_notes_buf_free( 1487 (unsigned long)__va(fw_dump.cpu_notes_buf), 1488 fw_dump.cpu_notes_buf_size); 1489 fw_dump.cpu_notes_buf = 0; 1490 fw_dump.cpu_notes_buf_size = 0; 1491 } 1492 /* Initialize the kernel dump memory structure for FAD registration. */ 1493 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1494 } 1495 1496 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1497 struct kobj_attribute *attr, 1498 const char *buf, size_t count) 1499 { 1500 int input = -1; 1501 1502 if (!fw_dump.dump_active) 1503 return -EPERM; 1504 1505 if (kstrtoint(buf, 0, &input)) 1506 return -EINVAL; 1507 1508 if (input == 1) { 1509 /* 1510 * Take away the '/proc/vmcore'. We are releasing the dump 1511 * memory, hence it will not be valid anymore. 1512 */ 1513 #ifdef CONFIG_PROC_VMCORE 1514 vmcore_cleanup(); 1515 #endif 1516 fadump_invalidate_release_mem(); 1517 1518 } else 1519 return -EINVAL; 1520 return count; 1521 } 1522 1523 static ssize_t fadump_enabled_show(struct kobject *kobj, 1524 struct kobj_attribute *attr, 1525 char *buf) 1526 { 1527 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1528 } 1529 1530 static ssize_t fadump_register_show(struct kobject *kobj, 1531 struct kobj_attribute *attr, 1532 char *buf) 1533 { 1534 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1535 } 1536 1537 static ssize_t fadump_register_store(struct kobject *kobj, 1538 struct kobj_attribute *attr, 1539 const char *buf, size_t count) 1540 { 1541 int ret = 0; 1542 int input = -1; 1543 1544 if (!fw_dump.fadump_enabled || fdm_active) 1545 return -EPERM; 1546 1547 if (kstrtoint(buf, 0, &input)) 1548 return -EINVAL; 1549 1550 mutex_lock(&fadump_mutex); 1551 1552 switch (input) { 1553 case 0: 1554 if (fw_dump.dump_registered == 0) { 1555 goto unlock_out; 1556 } 1557 /* Un-register Firmware-assisted dump */ 1558 fadump_unregister_dump(&fdm); 1559 break; 1560 case 1: 1561 if (fw_dump.dump_registered == 1) { 1562 /* Un-register Firmware-assisted dump */ 1563 fadump_unregister_dump(&fdm); 1564 } 1565 /* Register Firmware-assisted dump */ 1566 ret = register_fadump(); 1567 break; 1568 default: 1569 ret = -EINVAL; 1570 break; 1571 } 1572 1573 unlock_out: 1574 mutex_unlock(&fadump_mutex); 1575 return ret < 0 ? ret : count; 1576 } 1577 1578 static int fadump_region_show(struct seq_file *m, void *private) 1579 { 1580 const struct fadump_mem_struct *fdm_ptr; 1581 1582 if (!fw_dump.fadump_enabled) 1583 return 0; 1584 1585 mutex_lock(&fadump_mutex); 1586 if (fdm_active) 1587 fdm_ptr = fdm_active; 1588 else { 1589 mutex_unlock(&fadump_mutex); 1590 fdm_ptr = &fdm; 1591 } 1592 1593 seq_printf(m, 1594 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1595 "Dumped: %#llx\n", 1596 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1597 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1598 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1599 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1600 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1601 seq_printf(m, 1602 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1603 "Dumped: %#llx\n", 1604 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1605 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1606 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1607 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1608 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1609 seq_printf(m, 1610 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1611 "Dumped: %#llx\n", 1612 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1613 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1614 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1615 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1616 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1617 1618 if (!fdm_active || 1619 (fw_dump.reserve_dump_area_start == 1620 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1621 goto out; 1622 1623 /* Dump is active. Show reserved memory region. */ 1624 seq_printf(m, 1625 " : [%#016llx-%#016llx] %#llx bytes, " 1626 "Dumped: %#llx\n", 1627 (unsigned long long)fw_dump.reserve_dump_area_start, 1628 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1629 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1630 fw_dump.reserve_dump_area_start, 1631 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1632 fw_dump.reserve_dump_area_start); 1633 out: 1634 if (fdm_active) 1635 mutex_unlock(&fadump_mutex); 1636 return 0; 1637 } 1638 1639 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1640 0200, NULL, 1641 fadump_release_memory_store); 1642 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1643 0444, fadump_enabled_show, 1644 NULL); 1645 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1646 0644, fadump_register_show, 1647 fadump_register_store); 1648 1649 DEFINE_SHOW_ATTRIBUTE(fadump_region); 1650 1651 static void fadump_init_files(void) 1652 { 1653 struct dentry *debugfs_file; 1654 int rc = 0; 1655 1656 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1657 if (rc) 1658 printk(KERN_ERR "fadump: unable to create sysfs file" 1659 " fadump_enabled (%d)\n", rc); 1660 1661 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1662 if (rc) 1663 printk(KERN_ERR "fadump: unable to create sysfs file" 1664 " fadump_registered (%d)\n", rc); 1665 1666 debugfs_file = debugfs_create_file("fadump_region", 0444, 1667 powerpc_debugfs_root, NULL, 1668 &fadump_region_fops); 1669 if (!debugfs_file) 1670 printk(KERN_ERR "fadump: unable to create debugfs file" 1671 " fadump_region\n"); 1672 1673 if (fw_dump.dump_active) { 1674 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1675 if (rc) 1676 printk(KERN_ERR "fadump: unable to create sysfs file" 1677 " fadump_release_mem (%d)\n", rc); 1678 } 1679 return; 1680 } 1681 1682 /* 1683 * Prepare for firmware-assisted dump. 1684 */ 1685 int __init setup_fadump(void) 1686 { 1687 if (!fw_dump.fadump_enabled) 1688 return 0; 1689 1690 if (!fw_dump.fadump_supported) { 1691 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1692 " this hardware\n"); 1693 return 0; 1694 } 1695 1696 fadump_show_config(); 1697 /* 1698 * If dump data is available then see if it is valid and prepare for 1699 * saving it to the disk. 1700 */ 1701 if (fw_dump.dump_active) { 1702 /* 1703 * if dump process fails then invalidate the registration 1704 * and release memory before proceeding for re-registration. 1705 */ 1706 if (process_fadump(fdm_active) < 0) 1707 fadump_invalidate_release_mem(); 1708 } 1709 /* Initialize the kernel dump memory structure for FAD registration. */ 1710 else if (fw_dump.reserve_dump_area_size) 1711 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1712 fadump_init_files(); 1713 1714 return 1; 1715 } 1716 subsys_initcall(setup_fadump); 1717