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 unsigned long size; 213 214 /* 215 * Check if the size is specified through fadump_reserve_mem= cmdline 216 * option. If yes, then use that. 217 */ 218 if (fw_dump.reserve_bootvar) 219 return fw_dump.reserve_bootvar; 220 221 /* divide by 20 to get 5% of value */ 222 size = memblock_end_of_DRAM() / 20; 223 224 /* round it down in multiples of 256 */ 225 size = size & ~0x0FFFFFFFUL; 226 227 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 228 if (memory_limit && size > memory_limit) 229 size = memory_limit; 230 231 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 232 } 233 234 /* 235 * Calculate the total memory size required to be reserved for 236 * firmware-assisted dump registration. 237 */ 238 static unsigned long get_fadump_area_size(void) 239 { 240 unsigned long size = 0; 241 242 size += fw_dump.cpu_state_data_size; 243 size += fw_dump.hpte_region_size; 244 size += fw_dump.boot_memory_size; 245 size += sizeof(struct fadump_crash_info_header); 246 size += sizeof(struct elfhdr); /* ELF core header.*/ 247 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 248 /* Program headers for crash memory regions. */ 249 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 250 251 size = PAGE_ALIGN(size); 252 return size; 253 } 254 255 int __init fadump_reserve_mem(void) 256 { 257 unsigned long base, size, memory_boundary; 258 259 if (!fw_dump.fadump_enabled) 260 return 0; 261 262 if (!fw_dump.fadump_supported) { 263 printk(KERN_INFO "Firmware-assisted dump is not supported on" 264 " this hardware\n"); 265 fw_dump.fadump_enabled = 0; 266 return 0; 267 } 268 /* 269 * Initialize boot memory size 270 * If dump is active then we have already calculated the size during 271 * first kernel. 272 */ 273 if (fdm_active) 274 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 275 else 276 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 277 278 /* 279 * Calculate the memory boundary. 280 * If memory_limit is less than actual memory boundary then reserve 281 * the memory for fadump beyond the memory_limit and adjust the 282 * memory_limit accordingly, so that the running kernel can run with 283 * specified memory_limit. 284 */ 285 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 286 size = get_fadump_area_size(); 287 if ((memory_limit + size) < memblock_end_of_DRAM()) 288 memory_limit += size; 289 else 290 memory_limit = memblock_end_of_DRAM(); 291 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 292 " dump, now %#016llx\n", memory_limit); 293 } 294 if (memory_limit) 295 memory_boundary = memory_limit; 296 else 297 memory_boundary = memblock_end_of_DRAM(); 298 299 if (fw_dump.dump_active) { 300 printk(KERN_INFO "Firmware-assisted dump is active.\n"); 301 /* 302 * If last boot has crashed then reserve all the memory 303 * above boot_memory_size so that we don't touch it until 304 * dump is written to disk by userspace tool. This memory 305 * will be released for general use once the dump is saved. 306 */ 307 base = fw_dump.boot_memory_size; 308 size = memory_boundary - base; 309 memblock_reserve(base, size); 310 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " 311 "for saving crash dump\n", 312 (unsigned long)(size >> 20), 313 (unsigned long)(base >> 20)); 314 315 fw_dump.fadumphdr_addr = 316 be64_to_cpu(fdm_active->rmr_region.destination_address) + 317 be64_to_cpu(fdm_active->rmr_region.source_len); 318 pr_debug("fadumphdr_addr = %p\n", 319 (void *) fw_dump.fadumphdr_addr); 320 } else { 321 size = get_fadump_area_size(); 322 323 /* 324 * Reserve memory at an offset closer to bottom of the RAM to 325 * minimize the impact of memory hot-remove operation. We can't 326 * use memblock_find_in_range() here since it doesn't allocate 327 * from bottom to top. 328 */ 329 for (base = fw_dump.boot_memory_size; 330 base <= (memory_boundary - size); 331 base += size) { 332 if (memblock_is_region_memory(base, size) && 333 !memblock_is_region_reserved(base, size)) 334 break; 335 } 336 if ((base > (memory_boundary - size)) || 337 memblock_reserve(base, size)) { 338 pr_err("Failed to reserve memory\n"); 339 return 0; 340 } 341 342 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 343 "assisted dump (System RAM: %ldMB)\n", 344 (unsigned long)(size >> 20), 345 (unsigned long)(base >> 20), 346 (unsigned long)(memblock_phys_mem_size() >> 20)); 347 } 348 349 fw_dump.reserve_dump_area_start = base; 350 fw_dump.reserve_dump_area_size = size; 351 return 1; 352 } 353 354 unsigned long __init arch_reserved_kernel_pages(void) 355 { 356 return memblock_reserved_size() / PAGE_SIZE; 357 } 358 359 /* Look for fadump= cmdline option. */ 360 static int __init early_fadump_param(char *p) 361 { 362 if (!p) 363 return 1; 364 365 if (strncmp(p, "on", 2) == 0) 366 fw_dump.fadump_enabled = 1; 367 else if (strncmp(p, "off", 3) == 0) 368 fw_dump.fadump_enabled = 0; 369 370 return 0; 371 } 372 early_param("fadump", early_fadump_param); 373 374 /* Look for fadump_reserve_mem= cmdline option */ 375 static int __init early_fadump_reserve_mem(char *p) 376 { 377 if (p) 378 fw_dump.reserve_bootvar = memparse(p, &p); 379 return 0; 380 } 381 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 382 383 static void register_fw_dump(struct fadump_mem_struct *fdm) 384 { 385 int rc; 386 unsigned int wait_time; 387 388 pr_debug("Registering for firmware-assisted kernel dump...\n"); 389 390 /* TODO: Add upper time limit for the delay */ 391 do { 392 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 393 FADUMP_REGISTER, fdm, 394 sizeof(struct fadump_mem_struct)); 395 396 wait_time = rtas_busy_delay_time(rc); 397 if (wait_time) 398 mdelay(wait_time); 399 400 } while (wait_time); 401 402 switch (rc) { 403 case -1: 404 printk(KERN_ERR "Failed to register firmware-assisted kernel" 405 " dump. Hardware Error(%d).\n", rc); 406 break; 407 case -3: 408 printk(KERN_ERR "Failed to register firmware-assisted kernel" 409 " dump. Parameter Error(%d).\n", rc); 410 break; 411 case -9: 412 printk(KERN_ERR "firmware-assisted kernel dump is already " 413 " registered."); 414 fw_dump.dump_registered = 1; 415 break; 416 case 0: 417 printk(KERN_INFO "firmware-assisted kernel dump registration" 418 " is successful\n"); 419 fw_dump.dump_registered = 1; 420 break; 421 } 422 } 423 424 void crash_fadump(struct pt_regs *regs, const char *str) 425 { 426 struct fadump_crash_info_header *fdh = NULL; 427 int old_cpu, this_cpu; 428 429 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 430 return; 431 432 /* 433 * old_cpu == -1 means this is the first CPU which has come here, 434 * go ahead and trigger fadump. 435 * 436 * old_cpu != -1 means some other CPU has already on it's way 437 * to trigger fadump, just keep looping here. 438 */ 439 this_cpu = smp_processor_id(); 440 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 441 442 if (old_cpu != -1) { 443 /* 444 * We can't loop here indefinitely. Wait as long as fadump 445 * is in force. If we race with fadump un-registration this 446 * loop will break and then we go down to normal panic path 447 * and reboot. If fadump is in force the first crashing 448 * cpu will definitely trigger fadump. 449 */ 450 while (fw_dump.dump_registered) 451 cpu_relax(); 452 return; 453 } 454 455 fdh = __va(fw_dump.fadumphdr_addr); 456 fdh->crashing_cpu = crashing_cpu; 457 crash_save_vmcoreinfo(); 458 459 if (regs) 460 fdh->regs = *regs; 461 else 462 ppc_save_regs(&fdh->regs); 463 464 fdh->online_mask = *cpu_online_mask; 465 466 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 467 rtas_os_term((char *)str); 468 } 469 470 #define GPR_MASK 0xffffff0000000000 471 static inline int fadump_gpr_index(u64 id) 472 { 473 int i = -1; 474 char str[3]; 475 476 if ((id & GPR_MASK) == REG_ID("GPR")) { 477 /* get the digits at the end */ 478 id &= ~GPR_MASK; 479 id >>= 24; 480 str[2] = '\0'; 481 str[1] = id & 0xff; 482 str[0] = (id >> 8) & 0xff; 483 sscanf(str, "%d", &i); 484 if (i > 31) 485 i = -1; 486 } 487 return i; 488 } 489 490 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 491 u64 reg_val) 492 { 493 int i; 494 495 i = fadump_gpr_index(reg_id); 496 if (i >= 0) 497 regs->gpr[i] = (unsigned long)reg_val; 498 else if (reg_id == REG_ID("NIA")) 499 regs->nip = (unsigned long)reg_val; 500 else if (reg_id == REG_ID("MSR")) 501 regs->msr = (unsigned long)reg_val; 502 else if (reg_id == REG_ID("CTR")) 503 regs->ctr = (unsigned long)reg_val; 504 else if (reg_id == REG_ID("LR")) 505 regs->link = (unsigned long)reg_val; 506 else if (reg_id == REG_ID("XER")) 507 regs->xer = (unsigned long)reg_val; 508 else if (reg_id == REG_ID("CR")) 509 regs->ccr = (unsigned long)reg_val; 510 else if (reg_id == REG_ID("DAR")) 511 regs->dar = (unsigned long)reg_val; 512 else if (reg_id == REG_ID("DSISR")) 513 regs->dsisr = (unsigned long)reg_val; 514 } 515 516 static struct fadump_reg_entry* 517 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 518 { 519 memset(regs, 0, sizeof(struct pt_regs)); 520 521 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 522 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 523 be64_to_cpu(reg_entry->reg_value)); 524 reg_entry++; 525 } 526 reg_entry++; 527 return reg_entry; 528 } 529 530 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type, 531 void *data, size_t data_len) 532 { 533 struct elf_note note; 534 535 note.n_namesz = strlen(name) + 1; 536 note.n_descsz = data_len; 537 note.n_type = type; 538 memcpy(buf, ¬e, sizeof(note)); 539 buf += (sizeof(note) + 3)/4; 540 memcpy(buf, name, note.n_namesz); 541 buf += (note.n_namesz + 3)/4; 542 memcpy(buf, data, note.n_descsz); 543 buf += (note.n_descsz + 3)/4; 544 545 return buf; 546 } 547 548 static void fadump_final_note(u32 *buf) 549 { 550 struct elf_note note; 551 552 note.n_namesz = 0; 553 note.n_descsz = 0; 554 note.n_type = 0; 555 memcpy(buf, ¬e, sizeof(note)); 556 } 557 558 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 559 { 560 struct elf_prstatus prstatus; 561 562 memset(&prstatus, 0, sizeof(prstatus)); 563 /* 564 * FIXME: How do i get PID? Do I really need it? 565 * prstatus.pr_pid = ???? 566 */ 567 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 568 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, 569 &prstatus, sizeof(prstatus)); 570 return buf; 571 } 572 573 static void fadump_update_elfcore_header(char *bufp) 574 { 575 struct elfhdr *elf; 576 struct elf_phdr *phdr; 577 578 elf = (struct elfhdr *)bufp; 579 bufp += sizeof(struct elfhdr); 580 581 /* First note is a place holder for cpu notes info. */ 582 phdr = (struct elf_phdr *)bufp; 583 584 if (phdr->p_type == PT_NOTE) { 585 phdr->p_paddr = fw_dump.cpu_notes_buf; 586 phdr->p_offset = phdr->p_paddr; 587 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 588 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 589 } 590 return; 591 } 592 593 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 594 { 595 void *vaddr; 596 struct page *page; 597 unsigned long order, count, i; 598 599 order = get_order(size); 600 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 601 if (!vaddr) 602 return NULL; 603 604 count = 1 << order; 605 page = virt_to_page(vaddr); 606 for (i = 0; i < count; i++) 607 SetPageReserved(page + i); 608 return vaddr; 609 } 610 611 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 612 { 613 struct page *page; 614 unsigned long order, count, i; 615 616 order = get_order(size); 617 count = 1 << order; 618 page = virt_to_page(vaddr); 619 for (i = 0; i < count; i++) 620 ClearPageReserved(page + i); 621 __free_pages(page, order); 622 } 623 624 /* 625 * Read CPU state dump data and convert it into ELF notes. 626 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 627 * used to access the data to allow for additional fields to be added without 628 * affecting compatibility. Each list of registers for a CPU starts with 629 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 630 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 631 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 632 * of register value. For more details refer to PAPR document. 633 * 634 * Only for the crashing cpu we ignore the CPU dump data and get exact 635 * state from fadump crash info structure populated by first kernel at the 636 * time of crash. 637 */ 638 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 639 { 640 struct fadump_reg_save_area_header *reg_header; 641 struct fadump_reg_entry *reg_entry; 642 struct fadump_crash_info_header *fdh = NULL; 643 void *vaddr; 644 unsigned long addr; 645 u32 num_cpus, *note_buf; 646 struct pt_regs regs; 647 int i, rc = 0, cpu = 0; 648 649 if (!fdm->cpu_state_data.bytes_dumped) 650 return -EINVAL; 651 652 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 653 vaddr = __va(addr); 654 655 reg_header = vaddr; 656 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 657 printk(KERN_ERR "Unable to read register save area.\n"); 658 return -ENOENT; 659 } 660 pr_debug("--------CPU State Data------------\n"); 661 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 662 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 663 664 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 665 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 666 pr_debug("NumCpus : %u\n", num_cpus); 667 vaddr += sizeof(u32); 668 reg_entry = (struct fadump_reg_entry *)vaddr; 669 670 /* Allocate buffer to hold cpu crash notes. */ 671 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 672 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 673 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 674 if (!note_buf) { 675 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 676 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 677 return -ENOMEM; 678 } 679 fw_dump.cpu_notes_buf = __pa(note_buf); 680 681 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 682 (num_cpus * sizeof(note_buf_t)), note_buf); 683 684 if (fw_dump.fadumphdr_addr) 685 fdh = __va(fw_dump.fadumphdr_addr); 686 687 for (i = 0; i < num_cpus; i++) { 688 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 689 printk(KERN_ERR "Unable to read CPU state data\n"); 690 rc = -ENOENT; 691 goto error_out; 692 } 693 /* Lower 4 bytes of reg_value contains logical cpu id */ 694 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 695 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 696 SKIP_TO_NEXT_CPU(reg_entry); 697 continue; 698 } 699 pr_debug("Reading register data for cpu %d...\n", cpu); 700 if (fdh && fdh->crashing_cpu == cpu) { 701 regs = fdh->regs; 702 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 703 SKIP_TO_NEXT_CPU(reg_entry); 704 } else { 705 reg_entry++; 706 reg_entry = fadump_read_registers(reg_entry, ®s); 707 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 708 } 709 } 710 fadump_final_note(note_buf); 711 712 if (fdh) { 713 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 714 fdh->elfcorehdr_addr); 715 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 716 } 717 return 0; 718 719 error_out: 720 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 721 fw_dump.cpu_notes_buf_size); 722 fw_dump.cpu_notes_buf = 0; 723 fw_dump.cpu_notes_buf_size = 0; 724 return rc; 725 726 } 727 728 /* 729 * Validate and process the dump data stored by firmware before exporting 730 * it through '/proc/vmcore'. 731 */ 732 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 733 { 734 struct fadump_crash_info_header *fdh; 735 int rc = 0; 736 737 if (!fdm_active || !fw_dump.fadumphdr_addr) 738 return -EINVAL; 739 740 /* Check if the dump data is valid. */ 741 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 742 (fdm_active->cpu_state_data.error_flags != 0) || 743 (fdm_active->rmr_region.error_flags != 0)) { 744 printk(KERN_ERR "Dump taken by platform is not valid\n"); 745 return -EINVAL; 746 } 747 if ((fdm_active->rmr_region.bytes_dumped != 748 fdm_active->rmr_region.source_len) || 749 !fdm_active->cpu_state_data.bytes_dumped) { 750 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 751 return -EINVAL; 752 } 753 754 /* Validate the fadump crash info header */ 755 fdh = __va(fw_dump.fadumphdr_addr); 756 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 757 printk(KERN_ERR "Crash info header is not valid.\n"); 758 return -EINVAL; 759 } 760 761 rc = fadump_build_cpu_notes(fdm_active); 762 if (rc) 763 return rc; 764 765 /* 766 * We are done validating dump info and elfcore header is now ready 767 * to be exported. set elfcorehdr_addr so that vmcore module will 768 * export the elfcore header through '/proc/vmcore'. 769 */ 770 elfcorehdr_addr = fdh->elfcorehdr_addr; 771 772 return 0; 773 } 774 775 static inline void fadump_add_crash_memory(unsigned long long base, 776 unsigned long long end) 777 { 778 if (base == end) 779 return; 780 781 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 782 crash_mem_ranges, base, end - 1, (end - base)); 783 crash_memory_ranges[crash_mem_ranges].base = base; 784 crash_memory_ranges[crash_mem_ranges].size = end - base; 785 crash_mem_ranges++; 786 } 787 788 static void fadump_exclude_reserved_area(unsigned long long start, 789 unsigned long long end) 790 { 791 unsigned long long ra_start, ra_end; 792 793 ra_start = fw_dump.reserve_dump_area_start; 794 ra_end = ra_start + fw_dump.reserve_dump_area_size; 795 796 if ((ra_start < end) && (ra_end > start)) { 797 if ((start < ra_start) && (end > ra_end)) { 798 fadump_add_crash_memory(start, ra_start); 799 fadump_add_crash_memory(ra_end, end); 800 } else if (start < ra_start) { 801 fadump_add_crash_memory(start, ra_start); 802 } else if (ra_end < end) { 803 fadump_add_crash_memory(ra_end, end); 804 } 805 } else 806 fadump_add_crash_memory(start, end); 807 } 808 809 static int fadump_init_elfcore_header(char *bufp) 810 { 811 struct elfhdr *elf; 812 813 elf = (struct elfhdr *) bufp; 814 bufp += sizeof(struct elfhdr); 815 memcpy(elf->e_ident, ELFMAG, SELFMAG); 816 elf->e_ident[EI_CLASS] = ELF_CLASS; 817 elf->e_ident[EI_DATA] = ELF_DATA; 818 elf->e_ident[EI_VERSION] = EV_CURRENT; 819 elf->e_ident[EI_OSABI] = ELF_OSABI; 820 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 821 elf->e_type = ET_CORE; 822 elf->e_machine = ELF_ARCH; 823 elf->e_version = EV_CURRENT; 824 elf->e_entry = 0; 825 elf->e_phoff = sizeof(struct elfhdr); 826 elf->e_shoff = 0; 827 #if defined(_CALL_ELF) 828 elf->e_flags = _CALL_ELF; 829 #else 830 elf->e_flags = 0; 831 #endif 832 elf->e_ehsize = sizeof(struct elfhdr); 833 elf->e_phentsize = sizeof(struct elf_phdr); 834 elf->e_phnum = 0; 835 elf->e_shentsize = 0; 836 elf->e_shnum = 0; 837 elf->e_shstrndx = 0; 838 839 return 0; 840 } 841 842 /* 843 * Traverse through memblock structure and setup crash memory ranges. These 844 * ranges will be used create PT_LOAD program headers in elfcore header. 845 */ 846 static void fadump_setup_crash_memory_ranges(void) 847 { 848 struct memblock_region *reg; 849 unsigned long long start, end; 850 851 pr_debug("Setup crash memory ranges.\n"); 852 crash_mem_ranges = 0; 853 /* 854 * add the first memory chunk (RMA_START through boot_memory_size) as 855 * a separate memory chunk. The reason is, at the time crash firmware 856 * will move the content of this memory chunk to different location 857 * specified during fadump registration. We need to create a separate 858 * program header for this chunk with the correct offset. 859 */ 860 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 861 862 for_each_memblock(memory, reg) { 863 start = (unsigned long long)reg->base; 864 end = start + (unsigned long long)reg->size; 865 if (start == RMA_START && end >= fw_dump.boot_memory_size) 866 start = fw_dump.boot_memory_size; 867 868 /* add this range excluding the reserved dump area. */ 869 fadump_exclude_reserved_area(start, end); 870 } 871 } 872 873 /* 874 * If the given physical address falls within the boot memory region then 875 * return the relocated address that points to the dump region reserved 876 * for saving initial boot memory contents. 877 */ 878 static inline unsigned long fadump_relocate(unsigned long paddr) 879 { 880 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 881 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 882 else 883 return paddr; 884 } 885 886 static int fadump_create_elfcore_headers(char *bufp) 887 { 888 struct elfhdr *elf; 889 struct elf_phdr *phdr; 890 int i; 891 892 fadump_init_elfcore_header(bufp); 893 elf = (struct elfhdr *)bufp; 894 bufp += sizeof(struct elfhdr); 895 896 /* 897 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 898 * will be populated during second kernel boot after crash. Hence 899 * this PT_NOTE will always be the first elf note. 900 * 901 * NOTE: Any new ELF note addition should be placed after this note. 902 */ 903 phdr = (struct elf_phdr *)bufp; 904 bufp += sizeof(struct elf_phdr); 905 phdr->p_type = PT_NOTE; 906 phdr->p_flags = 0; 907 phdr->p_vaddr = 0; 908 phdr->p_align = 0; 909 910 phdr->p_offset = 0; 911 phdr->p_paddr = 0; 912 phdr->p_filesz = 0; 913 phdr->p_memsz = 0; 914 915 (elf->e_phnum)++; 916 917 /* setup ELF PT_NOTE for vmcoreinfo */ 918 phdr = (struct elf_phdr *)bufp; 919 bufp += sizeof(struct elf_phdr); 920 phdr->p_type = PT_NOTE; 921 phdr->p_flags = 0; 922 phdr->p_vaddr = 0; 923 phdr->p_align = 0; 924 925 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 926 phdr->p_offset = phdr->p_paddr; 927 phdr->p_memsz = vmcoreinfo_max_size; 928 phdr->p_filesz = vmcoreinfo_max_size; 929 930 /* Increment number of program headers. */ 931 (elf->e_phnum)++; 932 933 /* setup PT_LOAD sections. */ 934 935 for (i = 0; i < crash_mem_ranges; i++) { 936 unsigned long long mbase, msize; 937 mbase = crash_memory_ranges[i].base; 938 msize = crash_memory_ranges[i].size; 939 940 if (!msize) 941 continue; 942 943 phdr = (struct elf_phdr *)bufp; 944 bufp += sizeof(struct elf_phdr); 945 phdr->p_type = PT_LOAD; 946 phdr->p_flags = PF_R|PF_W|PF_X; 947 phdr->p_offset = mbase; 948 949 if (mbase == RMA_START) { 950 /* 951 * The entire RMA region will be moved by firmware 952 * to the specified destination_address. Hence set 953 * the correct offset. 954 */ 955 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 956 } 957 958 phdr->p_paddr = mbase; 959 phdr->p_vaddr = (unsigned long)__va(mbase); 960 phdr->p_filesz = msize; 961 phdr->p_memsz = msize; 962 phdr->p_align = 0; 963 964 /* Increment number of program headers. */ 965 (elf->e_phnum)++; 966 } 967 return 0; 968 } 969 970 static unsigned long init_fadump_header(unsigned long addr) 971 { 972 struct fadump_crash_info_header *fdh; 973 974 if (!addr) 975 return 0; 976 977 fw_dump.fadumphdr_addr = addr; 978 fdh = __va(addr); 979 addr += sizeof(struct fadump_crash_info_header); 980 981 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 982 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 983 fdh->elfcorehdr_addr = addr; 984 /* We will set the crashing cpu id in crash_fadump() during crash. */ 985 fdh->crashing_cpu = CPU_UNKNOWN; 986 987 return addr; 988 } 989 990 static void register_fadump(void) 991 { 992 unsigned long addr; 993 void *vaddr; 994 995 /* 996 * If no memory is reserved then we can not register for firmware- 997 * assisted dump. 998 */ 999 if (!fw_dump.reserve_dump_area_size) 1000 return; 1001 1002 fadump_setup_crash_memory_ranges(); 1003 1004 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1005 /* Initialize fadump crash info header. */ 1006 addr = init_fadump_header(addr); 1007 vaddr = __va(addr); 1008 1009 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1010 fadump_create_elfcore_headers(vaddr); 1011 1012 /* register the future kernel dump with firmware. */ 1013 register_fw_dump(&fdm); 1014 } 1015 1016 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1017 { 1018 int rc = 0; 1019 unsigned int wait_time; 1020 1021 pr_debug("Un-register firmware-assisted dump\n"); 1022 1023 /* TODO: Add upper time limit for the delay */ 1024 do { 1025 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1026 FADUMP_UNREGISTER, fdm, 1027 sizeof(struct fadump_mem_struct)); 1028 1029 wait_time = rtas_busy_delay_time(rc); 1030 if (wait_time) 1031 mdelay(wait_time); 1032 } while (wait_time); 1033 1034 if (rc) { 1035 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1036 " unexpected error(%d).\n", rc); 1037 return rc; 1038 } 1039 fw_dump.dump_registered = 0; 1040 return 0; 1041 } 1042 1043 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1044 { 1045 int rc = 0; 1046 unsigned int wait_time; 1047 1048 pr_debug("Invalidating firmware-assisted dump registration\n"); 1049 1050 /* TODO: Add upper time limit for the delay */ 1051 do { 1052 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1053 FADUMP_INVALIDATE, fdm, 1054 sizeof(struct fadump_mem_struct)); 1055 1056 wait_time = rtas_busy_delay_time(rc); 1057 if (wait_time) 1058 mdelay(wait_time); 1059 } while (wait_time); 1060 1061 if (rc) { 1062 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1063 return rc; 1064 } 1065 fw_dump.dump_active = 0; 1066 fdm_active = NULL; 1067 return 0; 1068 } 1069 1070 void fadump_cleanup(void) 1071 { 1072 /* Invalidate the registration only if dump is active. */ 1073 if (fw_dump.dump_active) { 1074 init_fadump_mem_struct(&fdm, 1075 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1076 fadump_invalidate_dump(&fdm); 1077 } 1078 } 1079 1080 /* 1081 * Release the memory that was reserved in early boot to preserve the memory 1082 * contents. The released memory will be available for general use. 1083 */ 1084 static void fadump_release_memory(unsigned long begin, unsigned long end) 1085 { 1086 unsigned long addr; 1087 unsigned long ra_start, ra_end; 1088 1089 ra_start = fw_dump.reserve_dump_area_start; 1090 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1091 1092 for (addr = begin; addr < end; addr += PAGE_SIZE) { 1093 /* 1094 * exclude the dump reserve area. Will reuse it for next 1095 * fadump registration. 1096 */ 1097 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start)) 1098 continue; 1099 1100 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); 1101 } 1102 } 1103 1104 static void fadump_invalidate_release_mem(void) 1105 { 1106 unsigned long reserved_area_start, reserved_area_end; 1107 unsigned long destination_address; 1108 1109 mutex_lock(&fadump_mutex); 1110 if (!fw_dump.dump_active) { 1111 mutex_unlock(&fadump_mutex); 1112 return; 1113 } 1114 1115 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1116 fadump_cleanup(); 1117 mutex_unlock(&fadump_mutex); 1118 1119 /* 1120 * Save the current reserved memory bounds we will require them 1121 * later for releasing the memory for general use. 1122 */ 1123 reserved_area_start = fw_dump.reserve_dump_area_start; 1124 reserved_area_end = reserved_area_start + 1125 fw_dump.reserve_dump_area_size; 1126 /* 1127 * Setup reserve_dump_area_start and its size so that we can 1128 * reuse this reserved memory for Re-registration. 1129 */ 1130 fw_dump.reserve_dump_area_start = destination_address; 1131 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1132 1133 fadump_release_memory(reserved_area_start, reserved_area_end); 1134 if (fw_dump.cpu_notes_buf) { 1135 fadump_cpu_notes_buf_free( 1136 (unsigned long)__va(fw_dump.cpu_notes_buf), 1137 fw_dump.cpu_notes_buf_size); 1138 fw_dump.cpu_notes_buf = 0; 1139 fw_dump.cpu_notes_buf_size = 0; 1140 } 1141 /* Initialize the kernel dump memory structure for FAD registration. */ 1142 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1143 } 1144 1145 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1146 struct kobj_attribute *attr, 1147 const char *buf, size_t count) 1148 { 1149 if (!fw_dump.dump_active) 1150 return -EPERM; 1151 1152 if (buf[0] == '1') { 1153 /* 1154 * Take away the '/proc/vmcore'. We are releasing the dump 1155 * memory, hence it will not be valid anymore. 1156 */ 1157 #ifdef CONFIG_PROC_VMCORE 1158 vmcore_cleanup(); 1159 #endif 1160 fadump_invalidate_release_mem(); 1161 1162 } else 1163 return -EINVAL; 1164 return count; 1165 } 1166 1167 static ssize_t fadump_enabled_show(struct kobject *kobj, 1168 struct kobj_attribute *attr, 1169 char *buf) 1170 { 1171 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1172 } 1173 1174 static ssize_t fadump_register_show(struct kobject *kobj, 1175 struct kobj_attribute *attr, 1176 char *buf) 1177 { 1178 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1179 } 1180 1181 static ssize_t fadump_register_store(struct kobject *kobj, 1182 struct kobj_attribute *attr, 1183 const char *buf, size_t count) 1184 { 1185 int ret = 0; 1186 1187 if (!fw_dump.fadump_enabled || fdm_active) 1188 return -EPERM; 1189 1190 mutex_lock(&fadump_mutex); 1191 1192 switch (buf[0]) { 1193 case '0': 1194 if (fw_dump.dump_registered == 0) { 1195 ret = -EINVAL; 1196 goto unlock_out; 1197 } 1198 /* Un-register Firmware-assisted dump */ 1199 fadump_unregister_dump(&fdm); 1200 break; 1201 case '1': 1202 if (fw_dump.dump_registered == 1) { 1203 ret = -EINVAL; 1204 goto unlock_out; 1205 } 1206 /* Register Firmware-assisted dump */ 1207 register_fadump(); 1208 break; 1209 default: 1210 ret = -EINVAL; 1211 break; 1212 } 1213 1214 unlock_out: 1215 mutex_unlock(&fadump_mutex); 1216 return ret < 0 ? ret : count; 1217 } 1218 1219 static int fadump_region_show(struct seq_file *m, void *private) 1220 { 1221 const struct fadump_mem_struct *fdm_ptr; 1222 1223 if (!fw_dump.fadump_enabled) 1224 return 0; 1225 1226 mutex_lock(&fadump_mutex); 1227 if (fdm_active) 1228 fdm_ptr = fdm_active; 1229 else { 1230 mutex_unlock(&fadump_mutex); 1231 fdm_ptr = &fdm; 1232 } 1233 1234 seq_printf(m, 1235 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1236 "Dumped: %#llx\n", 1237 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1238 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1239 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1240 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1241 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1242 seq_printf(m, 1243 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1244 "Dumped: %#llx\n", 1245 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1246 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1247 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1248 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1249 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1250 seq_printf(m, 1251 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1252 "Dumped: %#llx\n", 1253 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1254 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1255 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1256 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1257 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1258 1259 if (!fdm_active || 1260 (fw_dump.reserve_dump_area_start == 1261 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1262 goto out; 1263 1264 /* Dump is active. Show reserved memory region. */ 1265 seq_printf(m, 1266 " : [%#016llx-%#016llx] %#llx bytes, " 1267 "Dumped: %#llx\n", 1268 (unsigned long long)fw_dump.reserve_dump_area_start, 1269 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1270 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1271 fw_dump.reserve_dump_area_start, 1272 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1273 fw_dump.reserve_dump_area_start); 1274 out: 1275 if (fdm_active) 1276 mutex_unlock(&fadump_mutex); 1277 return 0; 1278 } 1279 1280 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1281 0200, NULL, 1282 fadump_release_memory_store); 1283 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1284 0444, fadump_enabled_show, 1285 NULL); 1286 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1287 0644, fadump_register_show, 1288 fadump_register_store); 1289 1290 static int fadump_region_open(struct inode *inode, struct file *file) 1291 { 1292 return single_open(file, fadump_region_show, inode->i_private); 1293 } 1294 1295 static const struct file_operations fadump_region_fops = { 1296 .open = fadump_region_open, 1297 .read = seq_read, 1298 .llseek = seq_lseek, 1299 .release = single_release, 1300 }; 1301 1302 static void fadump_init_files(void) 1303 { 1304 struct dentry *debugfs_file; 1305 int rc = 0; 1306 1307 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1308 if (rc) 1309 printk(KERN_ERR "fadump: unable to create sysfs file" 1310 " fadump_enabled (%d)\n", rc); 1311 1312 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1313 if (rc) 1314 printk(KERN_ERR "fadump: unable to create sysfs file" 1315 " fadump_registered (%d)\n", rc); 1316 1317 debugfs_file = debugfs_create_file("fadump_region", 0444, 1318 powerpc_debugfs_root, NULL, 1319 &fadump_region_fops); 1320 if (!debugfs_file) 1321 printk(KERN_ERR "fadump: unable to create debugfs file" 1322 " fadump_region\n"); 1323 1324 if (fw_dump.dump_active) { 1325 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1326 if (rc) 1327 printk(KERN_ERR "fadump: unable to create sysfs file" 1328 " fadump_release_mem (%d)\n", rc); 1329 } 1330 return; 1331 } 1332 1333 /* 1334 * Prepare for firmware-assisted dump. 1335 */ 1336 int __init setup_fadump(void) 1337 { 1338 if (!fw_dump.fadump_enabled) 1339 return 0; 1340 1341 if (!fw_dump.fadump_supported) { 1342 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1343 " this hardware\n"); 1344 return 0; 1345 } 1346 1347 fadump_show_config(); 1348 /* 1349 * If dump data is available then see if it is valid and prepare for 1350 * saving it to the disk. 1351 */ 1352 if (fw_dump.dump_active) { 1353 /* 1354 * if dump process fails then invalidate the registration 1355 * and release memory before proceeding for re-registration. 1356 */ 1357 if (process_fadump(fdm_active) < 0) 1358 fadump_invalidate_release_mem(); 1359 } 1360 /* Initialize the kernel dump memory structure for FAD registration. */ 1361 else if (fw_dump.reserve_dump_area_size) 1362 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1363 fadump_init_files(); 1364 1365 return 1; 1366 } 1367 subsys_initcall(setup_fadump); 1368