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