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/debugfs.h> 34 #include <linux/seq_file.h> 35 #include <linux/crash_dump.h> 36 #include <linux/kobject.h> 37 #include <linux/sysfs.h> 38 39 #include <asm/page.h> 40 #include <asm/prom.h> 41 #include <asm/rtas.h> 42 #include <asm/fadump.h> 43 #include <asm/debug.h> 44 #include <asm/setup.h> 45 46 static struct fw_dump fw_dump; 47 static struct fadump_mem_struct fdm; 48 static const struct fadump_mem_struct *fdm_active; 49 50 static DEFINE_MUTEX(fadump_mutex); 51 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES]; 52 int crash_mem_ranges; 53 54 /* Scan the Firmware Assisted dump configuration details. */ 55 int __init early_init_dt_scan_fw_dump(unsigned long node, 56 const char *uname, int depth, void *data) 57 { 58 const __be32 *sections; 59 int i, num_sections; 60 int size; 61 const __be32 *token; 62 63 if (depth != 1 || strcmp(uname, "rtas") != 0) 64 return 0; 65 66 /* 67 * Check if Firmware Assisted dump is supported. if yes, check 68 * if dump has been initiated on last reboot. 69 */ 70 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 71 if (!token) 72 return 1; 73 74 fw_dump.fadump_supported = 1; 75 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 76 77 /* 78 * The 'ibm,kernel-dump' rtas node is present only if there is 79 * dump data waiting for us. 80 */ 81 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 82 if (fdm_active) 83 fw_dump.dump_active = 1; 84 85 /* Get the sizes required to store dump data for the firmware provided 86 * dump sections. 87 * For each dump section type supported, a 32bit cell which defines 88 * the ID of a supported section followed by two 32 bit cells which 89 * gives teh size of the section in bytes. 90 */ 91 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 92 &size); 93 94 if (!sections) 95 return 1; 96 97 num_sections = size / (3 * sizeof(u32)); 98 99 for (i = 0; i < num_sections; i++, sections += 3) { 100 u32 type = (u32)of_read_number(sections, 1); 101 102 switch (type) { 103 case FADUMP_CPU_STATE_DATA: 104 fw_dump.cpu_state_data_size = 105 of_read_ulong(§ions[1], 2); 106 break; 107 case FADUMP_HPTE_REGION: 108 fw_dump.hpte_region_size = 109 of_read_ulong(§ions[1], 2); 110 break; 111 } 112 } 113 114 return 1; 115 } 116 117 int is_fadump_active(void) 118 { 119 return fw_dump.dump_active; 120 } 121 122 /* Print firmware assisted dump configurations for debugging purpose. */ 123 static void fadump_show_config(void) 124 { 125 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 126 (fw_dump.fadump_supported ? "present" : "no support")); 127 128 if (!fw_dump.fadump_supported) 129 return; 130 131 pr_debug("Fadump enabled : %s\n", 132 (fw_dump.fadump_enabled ? "yes" : "no")); 133 pr_debug("Dump Active : %s\n", 134 (fw_dump.dump_active ? "yes" : "no")); 135 pr_debug("Dump section sizes:\n"); 136 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 137 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 138 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 139 } 140 141 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 142 unsigned long addr) 143 { 144 if (!fdm) 145 return 0; 146 147 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 148 addr = addr & PAGE_MASK; 149 150 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 151 fdm->header.dump_num_sections = cpu_to_be16(3); 152 fdm->header.dump_status_flag = 0; 153 fdm->header.offset_first_dump_section = 154 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 155 156 /* 157 * Fields for disk dump option. 158 * We are not using disk dump option, hence set these fields to 0. 159 */ 160 fdm->header.dd_block_size = 0; 161 fdm->header.dd_block_offset = 0; 162 fdm->header.dd_num_blocks = 0; 163 fdm->header.dd_offset_disk_path = 0; 164 165 /* set 0 to disable an automatic dump-reboot. */ 166 fdm->header.max_time_auto = 0; 167 168 /* Kernel dump sections */ 169 /* cpu state data section. */ 170 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 171 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 172 fdm->cpu_state_data.source_address = 0; 173 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 174 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 175 addr += fw_dump.cpu_state_data_size; 176 177 /* hpte region section */ 178 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 179 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 180 fdm->hpte_region.source_address = 0; 181 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 182 fdm->hpte_region.destination_address = cpu_to_be64(addr); 183 addr += fw_dump.hpte_region_size; 184 185 /* RMA region section */ 186 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 187 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 188 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 189 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 190 fdm->rmr_region.destination_address = cpu_to_be64(addr); 191 addr += fw_dump.boot_memory_size; 192 193 return addr; 194 } 195 196 /** 197 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 198 * 199 * Function to find the largest memory size we need to reserve during early 200 * boot process. This will be the size of the memory that is required for a 201 * kernel to boot successfully. 202 * 203 * This function has been taken from phyp-assisted dump feature implementation. 204 * 205 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 206 * 207 * TODO: Come up with better approach to find out more accurate memory size 208 * that is required for a kernel to boot successfully. 209 * 210 */ 211 static inline unsigned long fadump_calculate_reserve_size(void) 212 { 213 unsigned long size; 214 215 /* 216 * Check if the size is specified through fadump_reserve_mem= cmdline 217 * option. If yes, then use that. 218 */ 219 if (fw_dump.reserve_bootvar) 220 return fw_dump.reserve_bootvar; 221 222 /* divide by 20 to get 5% of value */ 223 size = memblock_end_of_DRAM() / 20; 224 225 /* round it down in multiples of 256 */ 226 size = size & ~0x0FFFFFFFUL; 227 228 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 229 if (memory_limit && size > memory_limit) 230 size = memory_limit; 231 232 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 233 } 234 235 /* 236 * Calculate the total memory size required to be reserved for 237 * firmware-assisted dump registration. 238 */ 239 static unsigned long get_fadump_area_size(void) 240 { 241 unsigned long size = 0; 242 243 size += fw_dump.cpu_state_data_size; 244 size += fw_dump.hpte_region_size; 245 size += fw_dump.boot_memory_size; 246 size += sizeof(struct fadump_crash_info_header); 247 size += sizeof(struct elfhdr); /* ELF core header.*/ 248 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 249 /* Program headers for crash memory regions. */ 250 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 251 252 size = PAGE_ALIGN(size); 253 return size; 254 } 255 256 int __init fadump_reserve_mem(void) 257 { 258 unsigned long base, size, memory_boundary; 259 260 if (!fw_dump.fadump_enabled) 261 return 0; 262 263 if (!fw_dump.fadump_supported) { 264 printk(KERN_INFO "Firmware-assisted dump is not supported on" 265 " this hardware\n"); 266 fw_dump.fadump_enabled = 0; 267 return 0; 268 } 269 /* 270 * Initialize boot memory size 271 * If dump is active then we have already calculated the size during 272 * first kernel. 273 */ 274 if (fdm_active) 275 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 276 else 277 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 278 279 /* 280 * Calculate the memory boundary. 281 * If memory_limit is less than actual memory boundary then reserve 282 * the memory for fadump beyond the memory_limit and adjust the 283 * memory_limit accordingly, so that the running kernel can run with 284 * specified memory_limit. 285 */ 286 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 287 size = get_fadump_area_size(); 288 if ((memory_limit + size) < memblock_end_of_DRAM()) 289 memory_limit += size; 290 else 291 memory_limit = memblock_end_of_DRAM(); 292 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 293 " dump, now %#016llx\n", memory_limit); 294 } 295 if (memory_limit) 296 memory_boundary = memory_limit; 297 else 298 memory_boundary = memblock_end_of_DRAM(); 299 300 if (fw_dump.dump_active) { 301 printk(KERN_INFO "Firmware-assisted dump is active.\n"); 302 /* 303 * If last boot has crashed then reserve all the memory 304 * above boot_memory_size so that we don't touch it until 305 * dump is written to disk by userspace tool. This memory 306 * will be released for general use once the dump is saved. 307 */ 308 base = fw_dump.boot_memory_size; 309 size = memory_boundary - base; 310 memblock_reserve(base, size); 311 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " 312 "for saving crash dump\n", 313 (unsigned long)(size >> 20), 314 (unsigned long)(base >> 20)); 315 316 fw_dump.fadumphdr_addr = 317 be64_to_cpu(fdm_active->rmr_region.destination_address) + 318 be64_to_cpu(fdm_active->rmr_region.source_len); 319 pr_debug("fadumphdr_addr = %p\n", 320 (void *) fw_dump.fadumphdr_addr); 321 } else { 322 /* Reserve the memory at the top of memory. */ 323 size = get_fadump_area_size(); 324 base = memory_boundary - size; 325 memblock_reserve(base, size); 326 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " 327 "for firmware-assisted dump\n", 328 (unsigned long)(size >> 20), 329 (unsigned long)(base >> 20)); 330 } 331 fw_dump.reserve_dump_area_start = base; 332 fw_dump.reserve_dump_area_size = size; 333 return 1; 334 } 335 336 unsigned long __init arch_reserved_kernel_pages(void) 337 { 338 return memblock_reserved_size() / PAGE_SIZE; 339 } 340 341 /* Look for fadump= cmdline option. */ 342 static int __init early_fadump_param(char *p) 343 { 344 if (!p) 345 return 1; 346 347 if (strncmp(p, "on", 2) == 0) 348 fw_dump.fadump_enabled = 1; 349 else if (strncmp(p, "off", 3) == 0) 350 fw_dump.fadump_enabled = 0; 351 352 return 0; 353 } 354 early_param("fadump", early_fadump_param); 355 356 /* Look for fadump_reserve_mem= cmdline option */ 357 static int __init early_fadump_reserve_mem(char *p) 358 { 359 if (p) 360 fw_dump.reserve_bootvar = memparse(p, &p); 361 return 0; 362 } 363 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 364 365 static void register_fw_dump(struct fadump_mem_struct *fdm) 366 { 367 int rc; 368 unsigned int wait_time; 369 370 pr_debug("Registering for firmware-assisted kernel dump...\n"); 371 372 /* TODO: Add upper time limit for the delay */ 373 do { 374 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 375 FADUMP_REGISTER, fdm, 376 sizeof(struct fadump_mem_struct)); 377 378 wait_time = rtas_busy_delay_time(rc); 379 if (wait_time) 380 mdelay(wait_time); 381 382 } while (wait_time); 383 384 switch (rc) { 385 case -1: 386 printk(KERN_ERR "Failed to register firmware-assisted kernel" 387 " dump. Hardware Error(%d).\n", rc); 388 break; 389 case -3: 390 printk(KERN_ERR "Failed to register firmware-assisted kernel" 391 " dump. Parameter Error(%d).\n", rc); 392 break; 393 case -9: 394 printk(KERN_ERR "firmware-assisted kernel dump is already " 395 " registered."); 396 fw_dump.dump_registered = 1; 397 break; 398 case 0: 399 printk(KERN_INFO "firmware-assisted kernel dump registration" 400 " is successful\n"); 401 fw_dump.dump_registered = 1; 402 break; 403 } 404 } 405 406 void crash_fadump(struct pt_regs *regs, const char *str) 407 { 408 struct fadump_crash_info_header *fdh = NULL; 409 int old_cpu, this_cpu; 410 411 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 412 return; 413 414 /* 415 * old_cpu == -1 means this is the first CPU which has come here, 416 * go ahead and trigger fadump. 417 * 418 * old_cpu != -1 means some other CPU has already on it's way 419 * to trigger fadump, just keep looping here. 420 */ 421 this_cpu = smp_processor_id(); 422 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 423 424 if (old_cpu != -1) { 425 /* 426 * We can't loop here indefinitely. Wait as long as fadump 427 * is in force. If we race with fadump un-registration this 428 * loop will break and then we go down to normal panic path 429 * and reboot. If fadump is in force the first crashing 430 * cpu will definitely trigger fadump. 431 */ 432 while (fw_dump.dump_registered) 433 cpu_relax(); 434 return; 435 } 436 437 fdh = __va(fw_dump.fadumphdr_addr); 438 fdh->crashing_cpu = crashing_cpu; 439 crash_save_vmcoreinfo(); 440 441 if (regs) 442 fdh->regs = *regs; 443 else 444 ppc_save_regs(&fdh->regs); 445 446 fdh->online_mask = *cpu_online_mask; 447 448 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 449 rtas_os_term((char *)str); 450 } 451 452 #define GPR_MASK 0xffffff0000000000 453 static inline int fadump_gpr_index(u64 id) 454 { 455 int i = -1; 456 char str[3]; 457 458 if ((id & GPR_MASK) == REG_ID("GPR")) { 459 /* get the digits at the end */ 460 id &= ~GPR_MASK; 461 id >>= 24; 462 str[2] = '\0'; 463 str[1] = id & 0xff; 464 str[0] = (id >> 8) & 0xff; 465 sscanf(str, "%d", &i); 466 if (i > 31) 467 i = -1; 468 } 469 return i; 470 } 471 472 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 473 u64 reg_val) 474 { 475 int i; 476 477 i = fadump_gpr_index(reg_id); 478 if (i >= 0) 479 regs->gpr[i] = (unsigned long)reg_val; 480 else if (reg_id == REG_ID("NIA")) 481 regs->nip = (unsigned long)reg_val; 482 else if (reg_id == REG_ID("MSR")) 483 regs->msr = (unsigned long)reg_val; 484 else if (reg_id == REG_ID("CTR")) 485 regs->ctr = (unsigned long)reg_val; 486 else if (reg_id == REG_ID("LR")) 487 regs->link = (unsigned long)reg_val; 488 else if (reg_id == REG_ID("XER")) 489 regs->xer = (unsigned long)reg_val; 490 else if (reg_id == REG_ID("CR")) 491 regs->ccr = (unsigned long)reg_val; 492 else if (reg_id == REG_ID("DAR")) 493 regs->dar = (unsigned long)reg_val; 494 else if (reg_id == REG_ID("DSISR")) 495 regs->dsisr = (unsigned long)reg_val; 496 } 497 498 static struct fadump_reg_entry* 499 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 500 { 501 memset(regs, 0, sizeof(struct pt_regs)); 502 503 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 504 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 505 be64_to_cpu(reg_entry->reg_value)); 506 reg_entry++; 507 } 508 reg_entry++; 509 return reg_entry; 510 } 511 512 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type, 513 void *data, size_t data_len) 514 { 515 struct elf_note note; 516 517 note.n_namesz = strlen(name) + 1; 518 note.n_descsz = data_len; 519 note.n_type = type; 520 memcpy(buf, ¬e, sizeof(note)); 521 buf += (sizeof(note) + 3)/4; 522 memcpy(buf, name, note.n_namesz); 523 buf += (note.n_namesz + 3)/4; 524 memcpy(buf, data, note.n_descsz); 525 buf += (note.n_descsz + 3)/4; 526 527 return buf; 528 } 529 530 static void fadump_final_note(u32 *buf) 531 { 532 struct elf_note note; 533 534 note.n_namesz = 0; 535 note.n_descsz = 0; 536 note.n_type = 0; 537 memcpy(buf, ¬e, sizeof(note)); 538 } 539 540 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 541 { 542 struct elf_prstatus prstatus; 543 544 memset(&prstatus, 0, sizeof(prstatus)); 545 /* 546 * FIXME: How do i get PID? Do I really need it? 547 * prstatus.pr_pid = ???? 548 */ 549 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 550 buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, 551 &prstatus, sizeof(prstatus)); 552 return buf; 553 } 554 555 static void fadump_update_elfcore_header(char *bufp) 556 { 557 struct elfhdr *elf; 558 struct elf_phdr *phdr; 559 560 elf = (struct elfhdr *)bufp; 561 bufp += sizeof(struct elfhdr); 562 563 /* First note is a place holder for cpu notes info. */ 564 phdr = (struct elf_phdr *)bufp; 565 566 if (phdr->p_type == PT_NOTE) { 567 phdr->p_paddr = fw_dump.cpu_notes_buf; 568 phdr->p_offset = phdr->p_paddr; 569 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 570 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 571 } 572 return; 573 } 574 575 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 576 { 577 void *vaddr; 578 struct page *page; 579 unsigned long order, count, i; 580 581 order = get_order(size); 582 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 583 if (!vaddr) 584 return NULL; 585 586 count = 1 << order; 587 page = virt_to_page(vaddr); 588 for (i = 0; i < count; i++) 589 SetPageReserved(page + i); 590 return vaddr; 591 } 592 593 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 594 { 595 struct page *page; 596 unsigned long order, count, i; 597 598 order = get_order(size); 599 count = 1 << order; 600 page = virt_to_page(vaddr); 601 for (i = 0; i < count; i++) 602 ClearPageReserved(page + i); 603 __free_pages(page, order); 604 } 605 606 /* 607 * Read CPU state dump data and convert it into ELF notes. 608 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 609 * used to access the data to allow for additional fields to be added without 610 * affecting compatibility. Each list of registers for a CPU starts with 611 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 612 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 613 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 614 * of register value. For more details refer to PAPR document. 615 * 616 * Only for the crashing cpu we ignore the CPU dump data and get exact 617 * state from fadump crash info structure populated by first kernel at the 618 * time of crash. 619 */ 620 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 621 { 622 struct fadump_reg_save_area_header *reg_header; 623 struct fadump_reg_entry *reg_entry; 624 struct fadump_crash_info_header *fdh = NULL; 625 void *vaddr; 626 unsigned long addr; 627 u32 num_cpus, *note_buf; 628 struct pt_regs regs; 629 int i, rc = 0, cpu = 0; 630 631 if (!fdm->cpu_state_data.bytes_dumped) 632 return -EINVAL; 633 634 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 635 vaddr = __va(addr); 636 637 reg_header = vaddr; 638 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 639 printk(KERN_ERR "Unable to read register save area.\n"); 640 return -ENOENT; 641 } 642 pr_debug("--------CPU State Data------------\n"); 643 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 644 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 645 646 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 647 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 648 pr_debug("NumCpus : %u\n", num_cpus); 649 vaddr += sizeof(u32); 650 reg_entry = (struct fadump_reg_entry *)vaddr; 651 652 /* Allocate buffer to hold cpu crash notes. */ 653 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 654 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 655 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 656 if (!note_buf) { 657 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 658 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 659 return -ENOMEM; 660 } 661 fw_dump.cpu_notes_buf = __pa(note_buf); 662 663 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 664 (num_cpus * sizeof(note_buf_t)), note_buf); 665 666 if (fw_dump.fadumphdr_addr) 667 fdh = __va(fw_dump.fadumphdr_addr); 668 669 for (i = 0; i < num_cpus; i++) { 670 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 671 printk(KERN_ERR "Unable to read CPU state data\n"); 672 rc = -ENOENT; 673 goto error_out; 674 } 675 /* Lower 4 bytes of reg_value contains logical cpu id */ 676 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 677 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 678 SKIP_TO_NEXT_CPU(reg_entry); 679 continue; 680 } 681 pr_debug("Reading register data for cpu %d...\n", cpu); 682 if (fdh && fdh->crashing_cpu == cpu) { 683 regs = fdh->regs; 684 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 685 SKIP_TO_NEXT_CPU(reg_entry); 686 } else { 687 reg_entry++; 688 reg_entry = fadump_read_registers(reg_entry, ®s); 689 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 690 } 691 } 692 fadump_final_note(note_buf); 693 694 if (fdh) { 695 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 696 fdh->elfcorehdr_addr); 697 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 698 } 699 return 0; 700 701 error_out: 702 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 703 fw_dump.cpu_notes_buf_size); 704 fw_dump.cpu_notes_buf = 0; 705 fw_dump.cpu_notes_buf_size = 0; 706 return rc; 707 708 } 709 710 /* 711 * Validate and process the dump data stored by firmware before exporting 712 * it through '/proc/vmcore'. 713 */ 714 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 715 { 716 struct fadump_crash_info_header *fdh; 717 int rc = 0; 718 719 if (!fdm_active || !fw_dump.fadumphdr_addr) 720 return -EINVAL; 721 722 /* Check if the dump data is valid. */ 723 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 724 (fdm_active->cpu_state_data.error_flags != 0) || 725 (fdm_active->rmr_region.error_flags != 0)) { 726 printk(KERN_ERR "Dump taken by platform is not valid\n"); 727 return -EINVAL; 728 } 729 if ((fdm_active->rmr_region.bytes_dumped != 730 fdm_active->rmr_region.source_len) || 731 !fdm_active->cpu_state_data.bytes_dumped) { 732 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 733 return -EINVAL; 734 } 735 736 /* Validate the fadump crash info header */ 737 fdh = __va(fw_dump.fadumphdr_addr); 738 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 739 printk(KERN_ERR "Crash info header is not valid.\n"); 740 return -EINVAL; 741 } 742 743 rc = fadump_build_cpu_notes(fdm_active); 744 if (rc) 745 return rc; 746 747 /* 748 * We are done validating dump info and elfcore header is now ready 749 * to be exported. set elfcorehdr_addr so that vmcore module will 750 * export the elfcore header through '/proc/vmcore'. 751 */ 752 elfcorehdr_addr = fdh->elfcorehdr_addr; 753 754 return 0; 755 } 756 757 static inline void fadump_add_crash_memory(unsigned long long base, 758 unsigned long long end) 759 { 760 if (base == end) 761 return; 762 763 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 764 crash_mem_ranges, base, end - 1, (end - base)); 765 crash_memory_ranges[crash_mem_ranges].base = base; 766 crash_memory_ranges[crash_mem_ranges].size = end - base; 767 crash_mem_ranges++; 768 } 769 770 static void fadump_exclude_reserved_area(unsigned long long start, 771 unsigned long long end) 772 { 773 unsigned long long ra_start, ra_end; 774 775 ra_start = fw_dump.reserve_dump_area_start; 776 ra_end = ra_start + fw_dump.reserve_dump_area_size; 777 778 if ((ra_start < end) && (ra_end > start)) { 779 if ((start < ra_start) && (end > ra_end)) { 780 fadump_add_crash_memory(start, ra_start); 781 fadump_add_crash_memory(ra_end, end); 782 } else if (start < ra_start) { 783 fadump_add_crash_memory(start, ra_start); 784 } else if (ra_end < end) { 785 fadump_add_crash_memory(ra_end, end); 786 } 787 } else 788 fadump_add_crash_memory(start, end); 789 } 790 791 static int fadump_init_elfcore_header(char *bufp) 792 { 793 struct elfhdr *elf; 794 795 elf = (struct elfhdr *) bufp; 796 bufp += sizeof(struct elfhdr); 797 memcpy(elf->e_ident, ELFMAG, SELFMAG); 798 elf->e_ident[EI_CLASS] = ELF_CLASS; 799 elf->e_ident[EI_DATA] = ELF_DATA; 800 elf->e_ident[EI_VERSION] = EV_CURRENT; 801 elf->e_ident[EI_OSABI] = ELF_OSABI; 802 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 803 elf->e_type = ET_CORE; 804 elf->e_machine = ELF_ARCH; 805 elf->e_version = EV_CURRENT; 806 elf->e_entry = 0; 807 elf->e_phoff = sizeof(struct elfhdr); 808 elf->e_shoff = 0; 809 #if defined(_CALL_ELF) 810 elf->e_flags = _CALL_ELF; 811 #else 812 elf->e_flags = 0; 813 #endif 814 elf->e_ehsize = sizeof(struct elfhdr); 815 elf->e_phentsize = sizeof(struct elf_phdr); 816 elf->e_phnum = 0; 817 elf->e_shentsize = 0; 818 elf->e_shnum = 0; 819 elf->e_shstrndx = 0; 820 821 return 0; 822 } 823 824 /* 825 * Traverse through memblock structure and setup crash memory ranges. These 826 * ranges will be used create PT_LOAD program headers in elfcore header. 827 */ 828 static void fadump_setup_crash_memory_ranges(void) 829 { 830 struct memblock_region *reg; 831 unsigned long long start, end; 832 833 pr_debug("Setup crash memory ranges.\n"); 834 crash_mem_ranges = 0; 835 /* 836 * add the first memory chunk (RMA_START through boot_memory_size) as 837 * a separate memory chunk. The reason is, at the time crash firmware 838 * will move the content of this memory chunk to different location 839 * specified during fadump registration. We need to create a separate 840 * program header for this chunk with the correct offset. 841 */ 842 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 843 844 for_each_memblock(memory, reg) { 845 start = (unsigned long long)reg->base; 846 end = start + (unsigned long long)reg->size; 847 if (start == RMA_START && end >= fw_dump.boot_memory_size) 848 start = fw_dump.boot_memory_size; 849 850 /* add this range excluding the reserved dump area. */ 851 fadump_exclude_reserved_area(start, end); 852 } 853 } 854 855 /* 856 * If the given physical address falls within the boot memory region then 857 * return the relocated address that points to the dump region reserved 858 * for saving initial boot memory contents. 859 */ 860 static inline unsigned long fadump_relocate(unsigned long paddr) 861 { 862 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 863 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 864 else 865 return paddr; 866 } 867 868 static int fadump_create_elfcore_headers(char *bufp) 869 { 870 struct elfhdr *elf; 871 struct elf_phdr *phdr; 872 int i; 873 874 fadump_init_elfcore_header(bufp); 875 elf = (struct elfhdr *)bufp; 876 bufp += sizeof(struct elfhdr); 877 878 /* 879 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 880 * will be populated during second kernel boot after crash. Hence 881 * this PT_NOTE will always be the first elf note. 882 * 883 * NOTE: Any new ELF note addition should be placed after this note. 884 */ 885 phdr = (struct elf_phdr *)bufp; 886 bufp += sizeof(struct elf_phdr); 887 phdr->p_type = PT_NOTE; 888 phdr->p_flags = 0; 889 phdr->p_vaddr = 0; 890 phdr->p_align = 0; 891 892 phdr->p_offset = 0; 893 phdr->p_paddr = 0; 894 phdr->p_filesz = 0; 895 phdr->p_memsz = 0; 896 897 (elf->e_phnum)++; 898 899 /* setup ELF PT_NOTE for vmcoreinfo */ 900 phdr = (struct elf_phdr *)bufp; 901 bufp += sizeof(struct elf_phdr); 902 phdr->p_type = PT_NOTE; 903 phdr->p_flags = 0; 904 phdr->p_vaddr = 0; 905 phdr->p_align = 0; 906 907 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 908 phdr->p_offset = phdr->p_paddr; 909 phdr->p_memsz = vmcoreinfo_max_size; 910 phdr->p_filesz = vmcoreinfo_max_size; 911 912 /* Increment number of program headers. */ 913 (elf->e_phnum)++; 914 915 /* setup PT_LOAD sections. */ 916 917 for (i = 0; i < crash_mem_ranges; i++) { 918 unsigned long long mbase, msize; 919 mbase = crash_memory_ranges[i].base; 920 msize = crash_memory_ranges[i].size; 921 922 if (!msize) 923 continue; 924 925 phdr = (struct elf_phdr *)bufp; 926 bufp += sizeof(struct elf_phdr); 927 phdr->p_type = PT_LOAD; 928 phdr->p_flags = PF_R|PF_W|PF_X; 929 phdr->p_offset = mbase; 930 931 if (mbase == RMA_START) { 932 /* 933 * The entire RMA region will be moved by firmware 934 * to the specified destination_address. Hence set 935 * the correct offset. 936 */ 937 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 938 } 939 940 phdr->p_paddr = mbase; 941 phdr->p_vaddr = (unsigned long)__va(mbase); 942 phdr->p_filesz = msize; 943 phdr->p_memsz = msize; 944 phdr->p_align = 0; 945 946 /* Increment number of program headers. */ 947 (elf->e_phnum)++; 948 } 949 return 0; 950 } 951 952 static unsigned long init_fadump_header(unsigned long addr) 953 { 954 struct fadump_crash_info_header *fdh; 955 956 if (!addr) 957 return 0; 958 959 fw_dump.fadumphdr_addr = addr; 960 fdh = __va(addr); 961 addr += sizeof(struct fadump_crash_info_header); 962 963 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 964 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 965 fdh->elfcorehdr_addr = addr; 966 /* We will set the crashing cpu id in crash_fadump() during crash. */ 967 fdh->crashing_cpu = CPU_UNKNOWN; 968 969 return addr; 970 } 971 972 static void register_fadump(void) 973 { 974 unsigned long addr; 975 void *vaddr; 976 977 /* 978 * If no memory is reserved then we can not register for firmware- 979 * assisted dump. 980 */ 981 if (!fw_dump.reserve_dump_area_size) 982 return; 983 984 fadump_setup_crash_memory_ranges(); 985 986 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 987 /* Initialize fadump crash info header. */ 988 addr = init_fadump_header(addr); 989 vaddr = __va(addr); 990 991 pr_debug("Creating ELF core headers at %#016lx\n", addr); 992 fadump_create_elfcore_headers(vaddr); 993 994 /* register the future kernel dump with firmware. */ 995 register_fw_dump(&fdm); 996 } 997 998 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 999 { 1000 int rc = 0; 1001 unsigned int wait_time; 1002 1003 pr_debug("Un-register firmware-assisted dump\n"); 1004 1005 /* TODO: Add upper time limit for the delay */ 1006 do { 1007 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1008 FADUMP_UNREGISTER, fdm, 1009 sizeof(struct fadump_mem_struct)); 1010 1011 wait_time = rtas_busy_delay_time(rc); 1012 if (wait_time) 1013 mdelay(wait_time); 1014 } while (wait_time); 1015 1016 if (rc) { 1017 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1018 " unexpected error(%d).\n", rc); 1019 return rc; 1020 } 1021 fw_dump.dump_registered = 0; 1022 return 0; 1023 } 1024 1025 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1026 { 1027 int rc = 0; 1028 unsigned int wait_time; 1029 1030 pr_debug("Invalidating firmware-assisted dump registration\n"); 1031 1032 /* TODO: Add upper time limit for the delay */ 1033 do { 1034 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1035 FADUMP_INVALIDATE, fdm, 1036 sizeof(struct fadump_mem_struct)); 1037 1038 wait_time = rtas_busy_delay_time(rc); 1039 if (wait_time) 1040 mdelay(wait_time); 1041 } while (wait_time); 1042 1043 if (rc) { 1044 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1045 return rc; 1046 } 1047 fw_dump.dump_active = 0; 1048 fdm_active = NULL; 1049 return 0; 1050 } 1051 1052 void fadump_cleanup(void) 1053 { 1054 /* Invalidate the registration only if dump is active. */ 1055 if (fw_dump.dump_active) { 1056 init_fadump_mem_struct(&fdm, 1057 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1058 fadump_invalidate_dump(&fdm); 1059 } 1060 } 1061 1062 /* 1063 * Release the memory that was reserved in early boot to preserve the memory 1064 * contents. The released memory will be available for general use. 1065 */ 1066 static void fadump_release_memory(unsigned long begin, unsigned long end) 1067 { 1068 unsigned long addr; 1069 unsigned long ra_start, ra_end; 1070 1071 ra_start = fw_dump.reserve_dump_area_start; 1072 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1073 1074 for (addr = begin; addr < end; addr += PAGE_SIZE) { 1075 /* 1076 * exclude the dump reserve area. Will reuse it for next 1077 * fadump registration. 1078 */ 1079 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start)) 1080 continue; 1081 1082 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); 1083 } 1084 } 1085 1086 static void fadump_invalidate_release_mem(void) 1087 { 1088 unsigned long reserved_area_start, reserved_area_end; 1089 unsigned long destination_address; 1090 1091 mutex_lock(&fadump_mutex); 1092 if (!fw_dump.dump_active) { 1093 mutex_unlock(&fadump_mutex); 1094 return; 1095 } 1096 1097 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1098 fadump_cleanup(); 1099 mutex_unlock(&fadump_mutex); 1100 1101 /* 1102 * Save the current reserved memory bounds we will require them 1103 * later for releasing the memory for general use. 1104 */ 1105 reserved_area_start = fw_dump.reserve_dump_area_start; 1106 reserved_area_end = reserved_area_start + 1107 fw_dump.reserve_dump_area_size; 1108 /* 1109 * Setup reserve_dump_area_start and its size so that we can 1110 * reuse this reserved memory for Re-registration. 1111 */ 1112 fw_dump.reserve_dump_area_start = destination_address; 1113 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1114 1115 fadump_release_memory(reserved_area_start, reserved_area_end); 1116 if (fw_dump.cpu_notes_buf) { 1117 fadump_cpu_notes_buf_free( 1118 (unsigned long)__va(fw_dump.cpu_notes_buf), 1119 fw_dump.cpu_notes_buf_size); 1120 fw_dump.cpu_notes_buf = 0; 1121 fw_dump.cpu_notes_buf_size = 0; 1122 } 1123 /* Initialize the kernel dump memory structure for FAD registration. */ 1124 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1125 } 1126 1127 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1128 struct kobj_attribute *attr, 1129 const char *buf, size_t count) 1130 { 1131 if (!fw_dump.dump_active) 1132 return -EPERM; 1133 1134 if (buf[0] == '1') { 1135 /* 1136 * Take away the '/proc/vmcore'. We are releasing the dump 1137 * memory, hence it will not be valid anymore. 1138 */ 1139 #ifdef CONFIG_PROC_VMCORE 1140 vmcore_cleanup(); 1141 #endif 1142 fadump_invalidate_release_mem(); 1143 1144 } else 1145 return -EINVAL; 1146 return count; 1147 } 1148 1149 static ssize_t fadump_enabled_show(struct kobject *kobj, 1150 struct kobj_attribute *attr, 1151 char *buf) 1152 { 1153 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1154 } 1155 1156 static ssize_t fadump_register_show(struct kobject *kobj, 1157 struct kobj_attribute *attr, 1158 char *buf) 1159 { 1160 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1161 } 1162 1163 static ssize_t fadump_register_store(struct kobject *kobj, 1164 struct kobj_attribute *attr, 1165 const char *buf, size_t count) 1166 { 1167 int ret = 0; 1168 1169 if (!fw_dump.fadump_enabled || fdm_active) 1170 return -EPERM; 1171 1172 mutex_lock(&fadump_mutex); 1173 1174 switch (buf[0]) { 1175 case '0': 1176 if (fw_dump.dump_registered == 0) { 1177 ret = -EINVAL; 1178 goto unlock_out; 1179 } 1180 /* Un-register Firmware-assisted dump */ 1181 fadump_unregister_dump(&fdm); 1182 break; 1183 case '1': 1184 if (fw_dump.dump_registered == 1) { 1185 ret = -EINVAL; 1186 goto unlock_out; 1187 } 1188 /* Register Firmware-assisted dump */ 1189 register_fadump(); 1190 break; 1191 default: 1192 ret = -EINVAL; 1193 break; 1194 } 1195 1196 unlock_out: 1197 mutex_unlock(&fadump_mutex); 1198 return ret < 0 ? ret : count; 1199 } 1200 1201 static int fadump_region_show(struct seq_file *m, void *private) 1202 { 1203 const struct fadump_mem_struct *fdm_ptr; 1204 1205 if (!fw_dump.fadump_enabled) 1206 return 0; 1207 1208 mutex_lock(&fadump_mutex); 1209 if (fdm_active) 1210 fdm_ptr = fdm_active; 1211 else { 1212 mutex_unlock(&fadump_mutex); 1213 fdm_ptr = &fdm; 1214 } 1215 1216 seq_printf(m, 1217 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1218 "Dumped: %#llx\n", 1219 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1220 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1221 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1222 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1223 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1224 seq_printf(m, 1225 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1226 "Dumped: %#llx\n", 1227 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1228 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1229 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1230 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1231 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1232 seq_printf(m, 1233 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1234 "Dumped: %#llx\n", 1235 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1236 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1237 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1238 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1239 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1240 1241 if (!fdm_active || 1242 (fw_dump.reserve_dump_area_start == 1243 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1244 goto out; 1245 1246 /* Dump is active. Show reserved memory region. */ 1247 seq_printf(m, 1248 " : [%#016llx-%#016llx] %#llx bytes, " 1249 "Dumped: %#llx\n", 1250 (unsigned long long)fw_dump.reserve_dump_area_start, 1251 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1252 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1253 fw_dump.reserve_dump_area_start, 1254 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1255 fw_dump.reserve_dump_area_start); 1256 out: 1257 if (fdm_active) 1258 mutex_unlock(&fadump_mutex); 1259 return 0; 1260 } 1261 1262 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1263 0200, NULL, 1264 fadump_release_memory_store); 1265 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1266 0444, fadump_enabled_show, 1267 NULL); 1268 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1269 0644, fadump_register_show, 1270 fadump_register_store); 1271 1272 static int fadump_region_open(struct inode *inode, struct file *file) 1273 { 1274 return single_open(file, fadump_region_show, inode->i_private); 1275 } 1276 1277 static const struct file_operations fadump_region_fops = { 1278 .open = fadump_region_open, 1279 .read = seq_read, 1280 .llseek = seq_lseek, 1281 .release = single_release, 1282 }; 1283 1284 static void fadump_init_files(void) 1285 { 1286 struct dentry *debugfs_file; 1287 int rc = 0; 1288 1289 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1290 if (rc) 1291 printk(KERN_ERR "fadump: unable to create sysfs file" 1292 " fadump_enabled (%d)\n", rc); 1293 1294 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1295 if (rc) 1296 printk(KERN_ERR "fadump: unable to create sysfs file" 1297 " fadump_registered (%d)\n", rc); 1298 1299 debugfs_file = debugfs_create_file("fadump_region", 0444, 1300 powerpc_debugfs_root, NULL, 1301 &fadump_region_fops); 1302 if (!debugfs_file) 1303 printk(KERN_ERR "fadump: unable to create debugfs file" 1304 " fadump_region\n"); 1305 1306 if (fw_dump.dump_active) { 1307 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1308 if (rc) 1309 printk(KERN_ERR "fadump: unable to create sysfs file" 1310 " fadump_release_mem (%d)\n", rc); 1311 } 1312 return; 1313 } 1314 1315 /* 1316 * Prepare for firmware-assisted dump. 1317 */ 1318 int __init setup_fadump(void) 1319 { 1320 if (!fw_dump.fadump_enabled) 1321 return 0; 1322 1323 if (!fw_dump.fadump_supported) { 1324 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1325 " this hardware\n"); 1326 return 0; 1327 } 1328 1329 fadump_show_config(); 1330 /* 1331 * If dump data is available then see if it is valid and prepare for 1332 * saving it to the disk. 1333 */ 1334 if (fw_dump.dump_active) { 1335 /* 1336 * if dump process fails then invalidate the registration 1337 * and release memory before proceeding for re-registration. 1338 */ 1339 if (process_fadump(fdm_active) < 0) 1340 fadump_invalidate_release_mem(); 1341 } 1342 /* Initialize the kernel dump memory structure for FAD registration. */ 1343 else if (fw_dump.reserve_dump_area_size) 1344 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1345 fadump_init_files(); 1346 1347 return 1; 1348 } 1349 subsys_initcall(setup_fadump); 1350