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