1 /* 2 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash 3 * dump with assistance from firmware. This approach does not use kexec, 4 * instead firmware assists in booting the kdump kernel while preserving 5 * memory contents. The most of the code implementation has been adapted 6 * from phyp assisted dump implementation written by Linas Vepstas and 7 * Manish Ahuja 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 22 * 23 * Copyright 2011 IBM Corporation 24 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 25 */ 26 27 #undef DEBUG 28 #define pr_fmt(fmt) "fadump: " fmt 29 30 #include <linux/string.h> 31 #include <linux/memblock.h> 32 #include <linux/delay.h> 33 #include <linux/seq_file.h> 34 #include <linux/crash_dump.h> 35 #include <linux/kobject.h> 36 #include <linux/sysfs.h> 37 38 #include <asm/debugfs.h> 39 #include <asm/page.h> 40 #include <asm/prom.h> 41 #include <asm/rtas.h> 42 #include <asm/fadump.h> 43 #include <asm/setup.h> 44 45 static struct fw_dump fw_dump; 46 static struct fadump_mem_struct fdm; 47 static const struct fadump_mem_struct *fdm_active; 48 49 static DEFINE_MUTEX(fadump_mutex); 50 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES]; 51 int crash_mem_ranges; 52 53 /* Scan the Firmware Assisted dump configuration details. */ 54 int __init early_init_dt_scan_fw_dump(unsigned long node, 55 const char *uname, int depth, void *data) 56 { 57 const __be32 *sections; 58 int i, num_sections; 59 int size; 60 const __be32 *token; 61 62 if (depth != 1 || strcmp(uname, "rtas") != 0) 63 return 0; 64 65 /* 66 * Check if Firmware Assisted dump is supported. if yes, check 67 * if dump has been initiated on last reboot. 68 */ 69 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 70 if (!token) 71 return 1; 72 73 fw_dump.fadump_supported = 1; 74 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 75 76 /* 77 * The 'ibm,kernel-dump' rtas node is present only if there is 78 * dump data waiting for us. 79 */ 80 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 81 if (fdm_active) 82 fw_dump.dump_active = 1; 83 84 /* Get the sizes required to store dump data for the firmware provided 85 * dump sections. 86 * For each dump section type supported, a 32bit cell which defines 87 * the ID of a supported section followed by two 32 bit cells which 88 * gives teh size of the section in bytes. 89 */ 90 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 91 &size); 92 93 if (!sections) 94 return 1; 95 96 num_sections = size / (3 * sizeof(u32)); 97 98 for (i = 0; i < num_sections; i++, sections += 3) { 99 u32 type = (u32)of_read_number(sections, 1); 100 101 switch (type) { 102 case FADUMP_CPU_STATE_DATA: 103 fw_dump.cpu_state_data_size = 104 of_read_ulong(§ions[1], 2); 105 break; 106 case FADUMP_HPTE_REGION: 107 fw_dump.hpte_region_size = 108 of_read_ulong(§ions[1], 2); 109 break; 110 } 111 } 112 113 return 1; 114 } 115 116 /* 117 * If fadump is registered, check if the memory provided 118 * falls within boot memory area. 119 */ 120 int is_fadump_boot_memory_area(u64 addr, ulong size) 121 { 122 if (!fw_dump.dump_registered) 123 return 0; 124 125 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; 126 } 127 128 int is_fadump_active(void) 129 { 130 return fw_dump.dump_active; 131 } 132 133 /* 134 * Returns 1, if there are no holes in boot memory area, 135 * 0 otherwise. 136 */ 137 static int is_boot_memory_area_contiguous(void) 138 { 139 struct memblock_region *reg; 140 unsigned long tstart, tend; 141 unsigned long start_pfn = PHYS_PFN(RMA_START); 142 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size); 143 unsigned int ret = 0; 144 145 for_each_memblock(memory, reg) { 146 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 147 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 148 if (tstart < tend) { 149 /* Memory hole from start_pfn to tstart */ 150 if (tstart > start_pfn) 151 break; 152 153 if (tend == end_pfn) { 154 ret = 1; 155 break; 156 } 157 158 start_pfn = tend + 1; 159 } 160 } 161 162 return ret; 163 } 164 165 /* Print firmware assisted dump configurations for debugging purpose. */ 166 static void fadump_show_config(void) 167 { 168 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 169 (fw_dump.fadump_supported ? "present" : "no support")); 170 171 if (!fw_dump.fadump_supported) 172 return; 173 174 pr_debug("Fadump enabled : %s\n", 175 (fw_dump.fadump_enabled ? "yes" : "no")); 176 pr_debug("Dump Active : %s\n", 177 (fw_dump.dump_active ? "yes" : "no")); 178 pr_debug("Dump section sizes:\n"); 179 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 180 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 181 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 182 } 183 184 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 185 unsigned long addr) 186 { 187 if (!fdm) 188 return 0; 189 190 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 191 addr = addr & PAGE_MASK; 192 193 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 194 fdm->header.dump_num_sections = cpu_to_be16(3); 195 fdm->header.dump_status_flag = 0; 196 fdm->header.offset_first_dump_section = 197 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 198 199 /* 200 * Fields for disk dump option. 201 * We are not using disk dump option, hence set these fields to 0. 202 */ 203 fdm->header.dd_block_size = 0; 204 fdm->header.dd_block_offset = 0; 205 fdm->header.dd_num_blocks = 0; 206 fdm->header.dd_offset_disk_path = 0; 207 208 /* set 0 to disable an automatic dump-reboot. */ 209 fdm->header.max_time_auto = 0; 210 211 /* Kernel dump sections */ 212 /* cpu state data section. */ 213 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 214 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 215 fdm->cpu_state_data.source_address = 0; 216 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 217 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 218 addr += fw_dump.cpu_state_data_size; 219 220 /* hpte region section */ 221 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 222 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 223 fdm->hpte_region.source_address = 0; 224 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 225 fdm->hpte_region.destination_address = cpu_to_be64(addr); 226 addr += fw_dump.hpte_region_size; 227 228 /* RMA region section */ 229 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 230 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 231 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 232 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 233 fdm->rmr_region.destination_address = cpu_to_be64(addr); 234 addr += fw_dump.boot_memory_size; 235 236 return addr; 237 } 238 239 /** 240 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 241 * 242 * Function to find the largest memory size we need to reserve during early 243 * boot process. This will be the size of the memory that is required for a 244 * kernel to boot successfully. 245 * 246 * This function has been taken from phyp-assisted dump feature implementation. 247 * 248 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 249 * 250 * TODO: Come up with better approach to find out more accurate memory size 251 * that is required for a kernel to boot successfully. 252 * 253 */ 254 static inline unsigned long fadump_calculate_reserve_size(void) 255 { 256 int ret; 257 unsigned long long base, size; 258 259 if (fw_dump.reserve_bootvar) 260 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 261 262 /* 263 * Check if the size is specified through crashkernel= cmdline 264 * option. If yes, then use that but ignore base as fadump reserves 265 * memory at a predefined offset. 266 */ 267 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 268 &size, &base); 269 if (ret == 0 && size > 0) { 270 unsigned long max_size; 271 272 if (fw_dump.reserve_bootvar) 273 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 274 275 fw_dump.reserve_bootvar = (unsigned long)size; 276 277 /* 278 * Adjust if the boot memory size specified is above 279 * the upper limit. 280 */ 281 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 282 if (fw_dump.reserve_bootvar > max_size) { 283 fw_dump.reserve_bootvar = max_size; 284 pr_info("Adjusted boot memory size to %luMB\n", 285 (fw_dump.reserve_bootvar >> 20)); 286 } 287 288 return fw_dump.reserve_bootvar; 289 } else if (fw_dump.reserve_bootvar) { 290 /* 291 * 'fadump_reserve_mem=' is being used to reserve memory 292 * for firmware-assisted dump. 293 */ 294 return fw_dump.reserve_bootvar; 295 } 296 297 /* divide by 20 to get 5% of value */ 298 size = memblock_phys_mem_size() / 20; 299 300 /* round it down in multiples of 256 */ 301 size = size & ~0x0FFFFFFFUL; 302 303 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 304 if (memory_limit && size > memory_limit) 305 size = memory_limit; 306 307 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 308 } 309 310 /* 311 * Calculate the total memory size required to be reserved for 312 * firmware-assisted dump registration. 313 */ 314 static unsigned long get_fadump_area_size(void) 315 { 316 unsigned long size = 0; 317 318 size += fw_dump.cpu_state_data_size; 319 size += fw_dump.hpte_region_size; 320 size += fw_dump.boot_memory_size; 321 size += sizeof(struct fadump_crash_info_header); 322 size += sizeof(struct elfhdr); /* ELF core header.*/ 323 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 324 /* Program headers for crash memory regions. */ 325 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 326 327 size = PAGE_ALIGN(size); 328 return size; 329 } 330 331 int __init fadump_reserve_mem(void) 332 { 333 unsigned long base, size, memory_boundary; 334 335 if (!fw_dump.fadump_enabled) 336 return 0; 337 338 if (!fw_dump.fadump_supported) { 339 printk(KERN_INFO "Firmware-assisted dump is not supported on" 340 " this hardware\n"); 341 fw_dump.fadump_enabled = 0; 342 return 0; 343 } 344 /* 345 * Initialize boot memory size 346 * If dump is active then we have already calculated the size during 347 * first kernel. 348 */ 349 if (fdm_active) 350 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 351 else 352 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 353 354 /* 355 * Calculate the memory boundary. 356 * If memory_limit is less than actual memory boundary then reserve 357 * the memory for fadump beyond the memory_limit and adjust the 358 * memory_limit accordingly, so that the running kernel can run with 359 * specified memory_limit. 360 */ 361 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 362 size = get_fadump_area_size(); 363 if ((memory_limit + size) < memblock_end_of_DRAM()) 364 memory_limit += size; 365 else 366 memory_limit = memblock_end_of_DRAM(); 367 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 368 " dump, now %#016llx\n", memory_limit); 369 } 370 if (memory_limit) 371 memory_boundary = memory_limit; 372 else 373 memory_boundary = memblock_end_of_DRAM(); 374 375 if (fw_dump.dump_active) { 376 printk(KERN_INFO "Firmware-assisted dump is active.\n"); 377 /* 378 * If last boot has crashed then reserve all the memory 379 * above boot_memory_size so that we don't touch it until 380 * dump is written to disk by userspace tool. This memory 381 * will be released for general use once the dump is saved. 382 */ 383 base = fw_dump.boot_memory_size; 384 size = memory_boundary - base; 385 memblock_reserve(base, size); 386 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " 387 "for saving crash dump\n", 388 (unsigned long)(size >> 20), 389 (unsigned long)(base >> 20)); 390 391 fw_dump.fadumphdr_addr = 392 be64_to_cpu(fdm_active->rmr_region.destination_address) + 393 be64_to_cpu(fdm_active->rmr_region.source_len); 394 pr_debug("fadumphdr_addr = %p\n", 395 (void *) fw_dump.fadumphdr_addr); 396 } else { 397 size = get_fadump_area_size(); 398 399 /* 400 * Reserve memory at an offset closer to bottom of the RAM to 401 * minimize the impact of memory hot-remove operation. We can't 402 * use memblock_find_in_range() here since it doesn't allocate 403 * from bottom to top. 404 */ 405 for (base = fw_dump.boot_memory_size; 406 base <= (memory_boundary - size); 407 base += size) { 408 if (memblock_is_region_memory(base, size) && 409 !memblock_is_region_reserved(base, size)) 410 break; 411 } 412 if ((base > (memory_boundary - size)) || 413 memblock_reserve(base, size)) { 414 pr_err("Failed to reserve memory\n"); 415 return 0; 416 } 417 418 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 419 "assisted dump (System RAM: %ldMB)\n", 420 (unsigned long)(size >> 20), 421 (unsigned long)(base >> 20), 422 (unsigned long)(memblock_phys_mem_size() >> 20)); 423 } 424 425 fw_dump.reserve_dump_area_start = base; 426 fw_dump.reserve_dump_area_size = size; 427 return 1; 428 } 429 430 unsigned long __init arch_reserved_kernel_pages(void) 431 { 432 return memblock_reserved_size() / PAGE_SIZE; 433 } 434 435 /* Look for fadump= cmdline option. */ 436 static int __init early_fadump_param(char *p) 437 { 438 if (!p) 439 return 1; 440 441 if (strncmp(p, "on", 2) == 0) 442 fw_dump.fadump_enabled = 1; 443 else if (strncmp(p, "off", 3) == 0) 444 fw_dump.fadump_enabled = 0; 445 446 return 0; 447 } 448 early_param("fadump", early_fadump_param); 449 450 /* 451 * Look for fadump_reserve_mem= cmdline option 452 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 453 * the sooner 'crashkernel=' parameter is accustomed to. 454 */ 455 static int __init early_fadump_reserve_mem(char *p) 456 { 457 if (p) 458 fw_dump.reserve_bootvar = memparse(p, &p); 459 return 0; 460 } 461 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 462 463 static int register_fw_dump(struct fadump_mem_struct *fdm) 464 { 465 int rc, err; 466 unsigned int wait_time; 467 468 pr_debug("Registering for firmware-assisted kernel dump...\n"); 469 470 /* TODO: Add upper time limit for the delay */ 471 do { 472 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 473 FADUMP_REGISTER, fdm, 474 sizeof(struct fadump_mem_struct)); 475 476 wait_time = rtas_busy_delay_time(rc); 477 if (wait_time) 478 mdelay(wait_time); 479 480 } while (wait_time); 481 482 err = -EIO; 483 switch (rc) { 484 default: 485 pr_err("Failed to register. Unknown Error(%d).\n", rc); 486 break; 487 case -1: 488 printk(KERN_ERR "Failed to register firmware-assisted kernel" 489 " dump. Hardware Error(%d).\n", rc); 490 break; 491 case -3: 492 if (!is_boot_memory_area_contiguous()) 493 pr_err("Can't have holes in boot memory area while " 494 "registering fadump\n"); 495 496 printk(KERN_ERR "Failed to register firmware-assisted kernel" 497 " dump. Parameter Error(%d).\n", rc); 498 err = -EINVAL; 499 break; 500 case -9: 501 printk(KERN_ERR "firmware-assisted kernel dump is already " 502 " registered."); 503 fw_dump.dump_registered = 1; 504 err = -EEXIST; 505 break; 506 case 0: 507 printk(KERN_INFO "firmware-assisted kernel dump registration" 508 " is successful\n"); 509 fw_dump.dump_registered = 1; 510 err = 0; 511 break; 512 } 513 return err; 514 } 515 516 void crash_fadump(struct pt_regs *regs, const char *str) 517 { 518 struct fadump_crash_info_header *fdh = NULL; 519 int old_cpu, this_cpu; 520 521 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 522 return; 523 524 /* 525 * old_cpu == -1 means this is the first CPU which has come here, 526 * go ahead and trigger fadump. 527 * 528 * old_cpu != -1 means some other CPU has already on it's way 529 * to trigger fadump, just keep looping here. 530 */ 531 this_cpu = smp_processor_id(); 532 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 533 534 if (old_cpu != -1) { 535 /* 536 * We can't loop here indefinitely. Wait as long as fadump 537 * is in force. If we race with fadump un-registration this 538 * loop will break and then we go down to normal panic path 539 * and reboot. If fadump is in force the first crashing 540 * cpu will definitely trigger fadump. 541 */ 542 while (fw_dump.dump_registered) 543 cpu_relax(); 544 return; 545 } 546 547 fdh = __va(fw_dump.fadumphdr_addr); 548 fdh->crashing_cpu = crashing_cpu; 549 crash_save_vmcoreinfo(); 550 551 if (regs) 552 fdh->regs = *regs; 553 else 554 ppc_save_regs(&fdh->regs); 555 556 fdh->online_mask = *cpu_online_mask; 557 558 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 559 rtas_os_term((char *)str); 560 } 561 562 #define GPR_MASK 0xffffff0000000000 563 static inline int fadump_gpr_index(u64 id) 564 { 565 int i = -1; 566 char str[3]; 567 568 if ((id & GPR_MASK) == REG_ID("GPR")) { 569 /* get the digits at the end */ 570 id &= ~GPR_MASK; 571 id >>= 24; 572 str[2] = '\0'; 573 str[1] = id & 0xff; 574 str[0] = (id >> 8) & 0xff; 575 sscanf(str, "%d", &i); 576 if (i > 31) 577 i = -1; 578 } 579 return i; 580 } 581 582 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 583 u64 reg_val) 584 { 585 int i; 586 587 i = fadump_gpr_index(reg_id); 588 if (i >= 0) 589 regs->gpr[i] = (unsigned long)reg_val; 590 else if (reg_id == REG_ID("NIA")) 591 regs->nip = (unsigned long)reg_val; 592 else if (reg_id == REG_ID("MSR")) 593 regs->msr = (unsigned long)reg_val; 594 else if (reg_id == REG_ID("CTR")) 595 regs->ctr = (unsigned long)reg_val; 596 else if (reg_id == REG_ID("LR")) 597 regs->link = (unsigned long)reg_val; 598 else if (reg_id == REG_ID("XER")) 599 regs->xer = (unsigned long)reg_val; 600 else if (reg_id == REG_ID("CR")) 601 regs->ccr = (unsigned long)reg_val; 602 else if (reg_id == REG_ID("DAR")) 603 regs->dar = (unsigned long)reg_val; 604 else if (reg_id == REG_ID("DSISR")) 605 regs->dsisr = (unsigned long)reg_val; 606 } 607 608 static struct fadump_reg_entry* 609 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 610 { 611 memset(regs, 0, sizeof(struct pt_regs)); 612 613 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 614 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 615 be64_to_cpu(reg_entry->reg_value)); 616 reg_entry++; 617 } 618 reg_entry++; 619 return reg_entry; 620 } 621 622 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 623 { 624 struct elf_prstatus prstatus; 625 626 memset(&prstatus, 0, sizeof(prstatus)); 627 /* 628 * FIXME: How do i get PID? Do I really need it? 629 * prstatus.pr_pid = ???? 630 */ 631 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 632 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 633 &prstatus, sizeof(prstatus)); 634 return buf; 635 } 636 637 static void fadump_update_elfcore_header(char *bufp) 638 { 639 struct elfhdr *elf; 640 struct elf_phdr *phdr; 641 642 elf = (struct elfhdr *)bufp; 643 bufp += sizeof(struct elfhdr); 644 645 /* First note is a place holder for cpu notes info. */ 646 phdr = (struct elf_phdr *)bufp; 647 648 if (phdr->p_type == PT_NOTE) { 649 phdr->p_paddr = fw_dump.cpu_notes_buf; 650 phdr->p_offset = phdr->p_paddr; 651 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 652 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 653 } 654 return; 655 } 656 657 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 658 { 659 void *vaddr; 660 struct page *page; 661 unsigned long order, count, i; 662 663 order = get_order(size); 664 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 665 if (!vaddr) 666 return NULL; 667 668 count = 1 << order; 669 page = virt_to_page(vaddr); 670 for (i = 0; i < count; i++) 671 SetPageReserved(page + i); 672 return vaddr; 673 } 674 675 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 676 { 677 struct page *page; 678 unsigned long order, count, i; 679 680 order = get_order(size); 681 count = 1 << order; 682 page = virt_to_page(vaddr); 683 for (i = 0; i < count; i++) 684 ClearPageReserved(page + i); 685 __free_pages(page, order); 686 } 687 688 /* 689 * Read CPU state dump data and convert it into ELF notes. 690 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 691 * used to access the data to allow for additional fields to be added without 692 * affecting compatibility. Each list of registers for a CPU starts with 693 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 694 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 695 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 696 * of register value. For more details refer to PAPR document. 697 * 698 * Only for the crashing cpu we ignore the CPU dump data and get exact 699 * state from fadump crash info structure populated by first kernel at the 700 * time of crash. 701 */ 702 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 703 { 704 struct fadump_reg_save_area_header *reg_header; 705 struct fadump_reg_entry *reg_entry; 706 struct fadump_crash_info_header *fdh = NULL; 707 void *vaddr; 708 unsigned long addr; 709 u32 num_cpus, *note_buf; 710 struct pt_regs regs; 711 int i, rc = 0, cpu = 0; 712 713 if (!fdm->cpu_state_data.bytes_dumped) 714 return -EINVAL; 715 716 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 717 vaddr = __va(addr); 718 719 reg_header = vaddr; 720 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 721 printk(KERN_ERR "Unable to read register save area.\n"); 722 return -ENOENT; 723 } 724 pr_debug("--------CPU State Data------------\n"); 725 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 726 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 727 728 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 729 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 730 pr_debug("NumCpus : %u\n", num_cpus); 731 vaddr += sizeof(u32); 732 reg_entry = (struct fadump_reg_entry *)vaddr; 733 734 /* Allocate buffer to hold cpu crash notes. */ 735 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 736 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 737 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 738 if (!note_buf) { 739 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 740 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 741 return -ENOMEM; 742 } 743 fw_dump.cpu_notes_buf = __pa(note_buf); 744 745 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 746 (num_cpus * sizeof(note_buf_t)), note_buf); 747 748 if (fw_dump.fadumphdr_addr) 749 fdh = __va(fw_dump.fadumphdr_addr); 750 751 for (i = 0; i < num_cpus; i++) { 752 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 753 printk(KERN_ERR "Unable to read CPU state data\n"); 754 rc = -ENOENT; 755 goto error_out; 756 } 757 /* Lower 4 bytes of reg_value contains logical cpu id */ 758 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 759 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 760 SKIP_TO_NEXT_CPU(reg_entry); 761 continue; 762 } 763 pr_debug("Reading register data for cpu %d...\n", cpu); 764 if (fdh && fdh->crashing_cpu == cpu) { 765 regs = fdh->regs; 766 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 767 SKIP_TO_NEXT_CPU(reg_entry); 768 } else { 769 reg_entry++; 770 reg_entry = fadump_read_registers(reg_entry, ®s); 771 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 772 } 773 } 774 final_note(note_buf); 775 776 if (fdh) { 777 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 778 fdh->elfcorehdr_addr); 779 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 780 } 781 return 0; 782 783 error_out: 784 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 785 fw_dump.cpu_notes_buf_size); 786 fw_dump.cpu_notes_buf = 0; 787 fw_dump.cpu_notes_buf_size = 0; 788 return rc; 789 790 } 791 792 /* 793 * Validate and process the dump data stored by firmware before exporting 794 * it through '/proc/vmcore'. 795 */ 796 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 797 { 798 struct fadump_crash_info_header *fdh; 799 int rc = 0; 800 801 if (!fdm_active || !fw_dump.fadumphdr_addr) 802 return -EINVAL; 803 804 /* Check if the dump data is valid. */ 805 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 806 (fdm_active->cpu_state_data.error_flags != 0) || 807 (fdm_active->rmr_region.error_flags != 0)) { 808 printk(KERN_ERR "Dump taken by platform is not valid\n"); 809 return -EINVAL; 810 } 811 if ((fdm_active->rmr_region.bytes_dumped != 812 fdm_active->rmr_region.source_len) || 813 !fdm_active->cpu_state_data.bytes_dumped) { 814 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 815 return -EINVAL; 816 } 817 818 /* Validate the fadump crash info header */ 819 fdh = __va(fw_dump.fadumphdr_addr); 820 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 821 printk(KERN_ERR "Crash info header is not valid.\n"); 822 return -EINVAL; 823 } 824 825 rc = fadump_build_cpu_notes(fdm_active); 826 if (rc) 827 return rc; 828 829 /* 830 * We are done validating dump info and elfcore header is now ready 831 * to be exported. set elfcorehdr_addr so that vmcore module will 832 * export the elfcore header through '/proc/vmcore'. 833 */ 834 elfcorehdr_addr = fdh->elfcorehdr_addr; 835 836 return 0; 837 } 838 839 static inline void fadump_add_crash_memory(unsigned long long base, 840 unsigned long long end) 841 { 842 if (base == end) 843 return; 844 845 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 846 crash_mem_ranges, base, end - 1, (end - base)); 847 crash_memory_ranges[crash_mem_ranges].base = base; 848 crash_memory_ranges[crash_mem_ranges].size = end - base; 849 crash_mem_ranges++; 850 } 851 852 static void fadump_exclude_reserved_area(unsigned long long start, 853 unsigned long long end) 854 { 855 unsigned long long ra_start, ra_end; 856 857 ra_start = fw_dump.reserve_dump_area_start; 858 ra_end = ra_start + fw_dump.reserve_dump_area_size; 859 860 if ((ra_start < end) && (ra_end > start)) { 861 if ((start < ra_start) && (end > ra_end)) { 862 fadump_add_crash_memory(start, ra_start); 863 fadump_add_crash_memory(ra_end, end); 864 } else if (start < ra_start) { 865 fadump_add_crash_memory(start, ra_start); 866 } else if (ra_end < end) { 867 fadump_add_crash_memory(ra_end, end); 868 } 869 } else 870 fadump_add_crash_memory(start, end); 871 } 872 873 static int fadump_init_elfcore_header(char *bufp) 874 { 875 struct elfhdr *elf; 876 877 elf = (struct elfhdr *) bufp; 878 bufp += sizeof(struct elfhdr); 879 memcpy(elf->e_ident, ELFMAG, SELFMAG); 880 elf->e_ident[EI_CLASS] = ELF_CLASS; 881 elf->e_ident[EI_DATA] = ELF_DATA; 882 elf->e_ident[EI_VERSION] = EV_CURRENT; 883 elf->e_ident[EI_OSABI] = ELF_OSABI; 884 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 885 elf->e_type = ET_CORE; 886 elf->e_machine = ELF_ARCH; 887 elf->e_version = EV_CURRENT; 888 elf->e_entry = 0; 889 elf->e_phoff = sizeof(struct elfhdr); 890 elf->e_shoff = 0; 891 #if defined(_CALL_ELF) 892 elf->e_flags = _CALL_ELF; 893 #else 894 elf->e_flags = 0; 895 #endif 896 elf->e_ehsize = sizeof(struct elfhdr); 897 elf->e_phentsize = sizeof(struct elf_phdr); 898 elf->e_phnum = 0; 899 elf->e_shentsize = 0; 900 elf->e_shnum = 0; 901 elf->e_shstrndx = 0; 902 903 return 0; 904 } 905 906 /* 907 * Traverse through memblock structure and setup crash memory ranges. These 908 * ranges will be used create PT_LOAD program headers in elfcore header. 909 */ 910 static void fadump_setup_crash_memory_ranges(void) 911 { 912 struct memblock_region *reg; 913 unsigned long long start, end; 914 915 pr_debug("Setup crash memory ranges.\n"); 916 crash_mem_ranges = 0; 917 /* 918 * add the first memory chunk (RMA_START through boot_memory_size) as 919 * a separate memory chunk. The reason is, at the time crash firmware 920 * will move the content of this memory chunk to different location 921 * specified during fadump registration. We need to create a separate 922 * program header for this chunk with the correct offset. 923 */ 924 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 925 926 for_each_memblock(memory, reg) { 927 start = (unsigned long long)reg->base; 928 end = start + (unsigned long long)reg->size; 929 930 /* 931 * skip the first memory chunk that is already added (RMA_START 932 * through boot_memory_size). This logic needs a relook if and 933 * when RMA_START changes to a non-zero value. 934 */ 935 BUILD_BUG_ON(RMA_START != 0); 936 if (start < fw_dump.boot_memory_size) { 937 if (end > fw_dump.boot_memory_size) 938 start = fw_dump.boot_memory_size; 939 else 940 continue; 941 } 942 943 /* add this range excluding the reserved dump area. */ 944 fadump_exclude_reserved_area(start, end); 945 } 946 } 947 948 /* 949 * If the given physical address falls within the boot memory region then 950 * return the relocated address that points to the dump region reserved 951 * for saving initial boot memory contents. 952 */ 953 static inline unsigned long fadump_relocate(unsigned long paddr) 954 { 955 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 956 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 957 else 958 return paddr; 959 } 960 961 static int fadump_create_elfcore_headers(char *bufp) 962 { 963 struct elfhdr *elf; 964 struct elf_phdr *phdr; 965 int i; 966 967 fadump_init_elfcore_header(bufp); 968 elf = (struct elfhdr *)bufp; 969 bufp += sizeof(struct elfhdr); 970 971 /* 972 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 973 * will be populated during second kernel boot after crash. Hence 974 * this PT_NOTE will always be the first elf note. 975 * 976 * NOTE: Any new ELF note addition should be placed after this note. 977 */ 978 phdr = (struct elf_phdr *)bufp; 979 bufp += sizeof(struct elf_phdr); 980 phdr->p_type = PT_NOTE; 981 phdr->p_flags = 0; 982 phdr->p_vaddr = 0; 983 phdr->p_align = 0; 984 985 phdr->p_offset = 0; 986 phdr->p_paddr = 0; 987 phdr->p_filesz = 0; 988 phdr->p_memsz = 0; 989 990 (elf->e_phnum)++; 991 992 /* setup ELF PT_NOTE for vmcoreinfo */ 993 phdr = (struct elf_phdr *)bufp; 994 bufp += sizeof(struct elf_phdr); 995 phdr->p_type = PT_NOTE; 996 phdr->p_flags = 0; 997 phdr->p_vaddr = 0; 998 phdr->p_align = 0; 999 1000 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1001 phdr->p_offset = phdr->p_paddr; 1002 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1003 1004 /* Increment number of program headers. */ 1005 (elf->e_phnum)++; 1006 1007 /* setup PT_LOAD sections. */ 1008 1009 for (i = 0; i < crash_mem_ranges; i++) { 1010 unsigned long long mbase, msize; 1011 mbase = crash_memory_ranges[i].base; 1012 msize = crash_memory_ranges[i].size; 1013 1014 if (!msize) 1015 continue; 1016 1017 phdr = (struct elf_phdr *)bufp; 1018 bufp += sizeof(struct elf_phdr); 1019 phdr->p_type = PT_LOAD; 1020 phdr->p_flags = PF_R|PF_W|PF_X; 1021 phdr->p_offset = mbase; 1022 1023 if (mbase == RMA_START) { 1024 /* 1025 * The entire RMA region will be moved by firmware 1026 * to the specified destination_address. Hence set 1027 * the correct offset. 1028 */ 1029 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1030 } 1031 1032 phdr->p_paddr = mbase; 1033 phdr->p_vaddr = (unsigned long)__va(mbase); 1034 phdr->p_filesz = msize; 1035 phdr->p_memsz = msize; 1036 phdr->p_align = 0; 1037 1038 /* Increment number of program headers. */ 1039 (elf->e_phnum)++; 1040 } 1041 return 0; 1042 } 1043 1044 static unsigned long init_fadump_header(unsigned long addr) 1045 { 1046 struct fadump_crash_info_header *fdh; 1047 1048 if (!addr) 1049 return 0; 1050 1051 fw_dump.fadumphdr_addr = addr; 1052 fdh = __va(addr); 1053 addr += sizeof(struct fadump_crash_info_header); 1054 1055 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1056 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1057 fdh->elfcorehdr_addr = addr; 1058 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1059 fdh->crashing_cpu = CPU_UNKNOWN; 1060 1061 return addr; 1062 } 1063 1064 static int register_fadump(void) 1065 { 1066 unsigned long addr; 1067 void *vaddr; 1068 1069 /* 1070 * If no memory is reserved then we can not register for firmware- 1071 * assisted dump. 1072 */ 1073 if (!fw_dump.reserve_dump_area_size) 1074 return -ENODEV; 1075 1076 fadump_setup_crash_memory_ranges(); 1077 1078 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1079 /* Initialize fadump crash info header. */ 1080 addr = init_fadump_header(addr); 1081 vaddr = __va(addr); 1082 1083 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1084 fadump_create_elfcore_headers(vaddr); 1085 1086 /* register the future kernel dump with firmware. */ 1087 return register_fw_dump(&fdm); 1088 } 1089 1090 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1091 { 1092 int rc = 0; 1093 unsigned int wait_time; 1094 1095 pr_debug("Un-register firmware-assisted dump\n"); 1096 1097 /* TODO: Add upper time limit for the delay */ 1098 do { 1099 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1100 FADUMP_UNREGISTER, fdm, 1101 sizeof(struct fadump_mem_struct)); 1102 1103 wait_time = rtas_busy_delay_time(rc); 1104 if (wait_time) 1105 mdelay(wait_time); 1106 } while (wait_time); 1107 1108 if (rc) { 1109 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1110 " unexpected error(%d).\n", rc); 1111 return rc; 1112 } 1113 fw_dump.dump_registered = 0; 1114 return 0; 1115 } 1116 1117 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1118 { 1119 int rc = 0; 1120 unsigned int wait_time; 1121 1122 pr_debug("Invalidating firmware-assisted dump registration\n"); 1123 1124 /* TODO: Add upper time limit for the delay */ 1125 do { 1126 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1127 FADUMP_INVALIDATE, fdm, 1128 sizeof(struct fadump_mem_struct)); 1129 1130 wait_time = rtas_busy_delay_time(rc); 1131 if (wait_time) 1132 mdelay(wait_time); 1133 } while (wait_time); 1134 1135 if (rc) { 1136 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1137 return rc; 1138 } 1139 fw_dump.dump_active = 0; 1140 fdm_active = NULL; 1141 return 0; 1142 } 1143 1144 void fadump_cleanup(void) 1145 { 1146 /* Invalidate the registration only if dump is active. */ 1147 if (fw_dump.dump_active) { 1148 init_fadump_mem_struct(&fdm, 1149 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1150 fadump_invalidate_dump(&fdm); 1151 } 1152 } 1153 1154 static void fadump_free_reserved_memory(unsigned long start_pfn, 1155 unsigned long end_pfn) 1156 { 1157 unsigned long pfn; 1158 unsigned long time_limit = jiffies + HZ; 1159 1160 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1161 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1162 1163 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1164 free_reserved_page(pfn_to_page(pfn)); 1165 1166 if (time_after(jiffies, time_limit)) { 1167 cond_resched(); 1168 time_limit = jiffies + HZ; 1169 } 1170 } 1171 } 1172 1173 /* 1174 * Skip memory holes and free memory that was actually reserved. 1175 */ 1176 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1177 { 1178 struct memblock_region *reg; 1179 unsigned long tstart, tend; 1180 unsigned long start_pfn = PHYS_PFN(start); 1181 unsigned long end_pfn = PHYS_PFN(end); 1182 1183 for_each_memblock(memory, reg) { 1184 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1185 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1186 if (tstart < tend) { 1187 fadump_free_reserved_memory(tstart, tend); 1188 1189 if (tend == end_pfn) 1190 break; 1191 1192 start_pfn = tend + 1; 1193 } 1194 } 1195 } 1196 1197 /* 1198 * Release the memory that was reserved in early boot to preserve the memory 1199 * contents. The released memory will be available for general use. 1200 */ 1201 static void fadump_release_memory(unsigned long begin, unsigned long end) 1202 { 1203 unsigned long ra_start, ra_end; 1204 1205 ra_start = fw_dump.reserve_dump_area_start; 1206 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1207 1208 /* 1209 * exclude the dump reserve area. Will reuse it for next 1210 * fadump registration. 1211 */ 1212 if (begin < ra_end && end > ra_start) { 1213 if (begin < ra_start) 1214 fadump_release_reserved_area(begin, ra_start); 1215 if (end > ra_end) 1216 fadump_release_reserved_area(ra_end, end); 1217 } else 1218 fadump_release_reserved_area(begin, end); 1219 } 1220 1221 static void fadump_invalidate_release_mem(void) 1222 { 1223 unsigned long reserved_area_start, reserved_area_end; 1224 unsigned long destination_address; 1225 1226 mutex_lock(&fadump_mutex); 1227 if (!fw_dump.dump_active) { 1228 mutex_unlock(&fadump_mutex); 1229 return; 1230 } 1231 1232 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1233 fadump_cleanup(); 1234 mutex_unlock(&fadump_mutex); 1235 1236 /* 1237 * Save the current reserved memory bounds we will require them 1238 * later for releasing the memory for general use. 1239 */ 1240 reserved_area_start = fw_dump.reserve_dump_area_start; 1241 reserved_area_end = reserved_area_start + 1242 fw_dump.reserve_dump_area_size; 1243 /* 1244 * Setup reserve_dump_area_start and its size so that we can 1245 * reuse this reserved memory for Re-registration. 1246 */ 1247 fw_dump.reserve_dump_area_start = destination_address; 1248 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1249 1250 fadump_release_memory(reserved_area_start, reserved_area_end); 1251 if (fw_dump.cpu_notes_buf) { 1252 fadump_cpu_notes_buf_free( 1253 (unsigned long)__va(fw_dump.cpu_notes_buf), 1254 fw_dump.cpu_notes_buf_size); 1255 fw_dump.cpu_notes_buf = 0; 1256 fw_dump.cpu_notes_buf_size = 0; 1257 } 1258 /* Initialize the kernel dump memory structure for FAD registration. */ 1259 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1260 } 1261 1262 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1263 struct kobj_attribute *attr, 1264 const char *buf, size_t count) 1265 { 1266 if (!fw_dump.dump_active) 1267 return -EPERM; 1268 1269 if (buf[0] == '1') { 1270 /* 1271 * Take away the '/proc/vmcore'. We are releasing the dump 1272 * memory, hence it will not be valid anymore. 1273 */ 1274 #ifdef CONFIG_PROC_VMCORE 1275 vmcore_cleanup(); 1276 #endif 1277 fadump_invalidate_release_mem(); 1278 1279 } else 1280 return -EINVAL; 1281 return count; 1282 } 1283 1284 static ssize_t fadump_enabled_show(struct kobject *kobj, 1285 struct kobj_attribute *attr, 1286 char *buf) 1287 { 1288 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1289 } 1290 1291 static ssize_t fadump_register_show(struct kobject *kobj, 1292 struct kobj_attribute *attr, 1293 char *buf) 1294 { 1295 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1296 } 1297 1298 static ssize_t fadump_register_store(struct kobject *kobj, 1299 struct kobj_attribute *attr, 1300 const char *buf, size_t count) 1301 { 1302 int ret = 0; 1303 1304 if (!fw_dump.fadump_enabled || fdm_active) 1305 return -EPERM; 1306 1307 mutex_lock(&fadump_mutex); 1308 1309 switch (buf[0]) { 1310 case '0': 1311 if (fw_dump.dump_registered == 0) { 1312 goto unlock_out; 1313 } 1314 /* Un-register Firmware-assisted dump */ 1315 fadump_unregister_dump(&fdm); 1316 break; 1317 case '1': 1318 if (fw_dump.dump_registered == 1) { 1319 ret = -EEXIST; 1320 goto unlock_out; 1321 } 1322 /* Register Firmware-assisted dump */ 1323 ret = register_fadump(); 1324 break; 1325 default: 1326 ret = -EINVAL; 1327 break; 1328 } 1329 1330 unlock_out: 1331 mutex_unlock(&fadump_mutex); 1332 return ret < 0 ? ret : count; 1333 } 1334 1335 static int fadump_region_show(struct seq_file *m, void *private) 1336 { 1337 const struct fadump_mem_struct *fdm_ptr; 1338 1339 if (!fw_dump.fadump_enabled) 1340 return 0; 1341 1342 mutex_lock(&fadump_mutex); 1343 if (fdm_active) 1344 fdm_ptr = fdm_active; 1345 else { 1346 mutex_unlock(&fadump_mutex); 1347 fdm_ptr = &fdm; 1348 } 1349 1350 seq_printf(m, 1351 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1352 "Dumped: %#llx\n", 1353 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1354 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1355 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1356 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1357 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1358 seq_printf(m, 1359 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1360 "Dumped: %#llx\n", 1361 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1362 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1363 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1364 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1365 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1366 seq_printf(m, 1367 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1368 "Dumped: %#llx\n", 1369 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1370 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1371 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1372 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1373 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1374 1375 if (!fdm_active || 1376 (fw_dump.reserve_dump_area_start == 1377 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1378 goto out; 1379 1380 /* Dump is active. Show reserved memory region. */ 1381 seq_printf(m, 1382 " : [%#016llx-%#016llx] %#llx bytes, " 1383 "Dumped: %#llx\n", 1384 (unsigned long long)fw_dump.reserve_dump_area_start, 1385 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1386 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1387 fw_dump.reserve_dump_area_start, 1388 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1389 fw_dump.reserve_dump_area_start); 1390 out: 1391 if (fdm_active) 1392 mutex_unlock(&fadump_mutex); 1393 return 0; 1394 } 1395 1396 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1397 0200, NULL, 1398 fadump_release_memory_store); 1399 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1400 0444, fadump_enabled_show, 1401 NULL); 1402 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1403 0644, fadump_register_show, 1404 fadump_register_store); 1405 1406 static int fadump_region_open(struct inode *inode, struct file *file) 1407 { 1408 return single_open(file, fadump_region_show, inode->i_private); 1409 } 1410 1411 static const struct file_operations fadump_region_fops = { 1412 .open = fadump_region_open, 1413 .read = seq_read, 1414 .llseek = seq_lseek, 1415 .release = single_release, 1416 }; 1417 1418 static void fadump_init_files(void) 1419 { 1420 struct dentry *debugfs_file; 1421 int rc = 0; 1422 1423 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1424 if (rc) 1425 printk(KERN_ERR "fadump: unable to create sysfs file" 1426 " fadump_enabled (%d)\n", rc); 1427 1428 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1429 if (rc) 1430 printk(KERN_ERR "fadump: unable to create sysfs file" 1431 " fadump_registered (%d)\n", rc); 1432 1433 debugfs_file = debugfs_create_file("fadump_region", 0444, 1434 powerpc_debugfs_root, NULL, 1435 &fadump_region_fops); 1436 if (!debugfs_file) 1437 printk(KERN_ERR "fadump: unable to create debugfs file" 1438 " fadump_region\n"); 1439 1440 if (fw_dump.dump_active) { 1441 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1442 if (rc) 1443 printk(KERN_ERR "fadump: unable to create sysfs file" 1444 " fadump_release_mem (%d)\n", rc); 1445 } 1446 return; 1447 } 1448 1449 /* 1450 * Prepare for firmware-assisted dump. 1451 */ 1452 int __init setup_fadump(void) 1453 { 1454 if (!fw_dump.fadump_enabled) 1455 return 0; 1456 1457 if (!fw_dump.fadump_supported) { 1458 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1459 " this hardware\n"); 1460 return 0; 1461 } 1462 1463 fadump_show_config(); 1464 /* 1465 * If dump data is available then see if it is valid and prepare for 1466 * saving it to the disk. 1467 */ 1468 if (fw_dump.dump_active) { 1469 /* 1470 * if dump process fails then invalidate the registration 1471 * and release memory before proceeding for re-registration. 1472 */ 1473 if (process_fadump(fdm_active) < 0) 1474 fadump_invalidate_release_mem(); 1475 } 1476 /* Initialize the kernel dump memory structure for FAD registration. */ 1477 else if (fw_dump.reserve_dump_area_size) 1478 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1479 fadump_init_files(); 1480 1481 return 1; 1482 } 1483 subsys_initcall(setup_fadump); 1484