1 /* 2 * Firmware Assisted dump: A robust mechanism to get reliable kernel crash 3 * dump with assistance from firmware. This approach does not use kexec, 4 * instead firmware assists in booting the kdump kernel while preserving 5 * memory contents. The most of the code implementation has been adapted 6 * from phyp assisted dump implementation written by Linas Vepstas and 7 * Manish Ahuja 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 22 * 23 * Copyright 2011 IBM Corporation 24 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 25 */ 26 27 #undef DEBUG 28 #define pr_fmt(fmt) "fadump: " fmt 29 30 #include <linux/string.h> 31 #include <linux/memblock.h> 32 #include <linux/delay.h> 33 #include <linux/seq_file.h> 34 #include <linux/crash_dump.h> 35 #include <linux/kobject.h> 36 #include <linux/sysfs.h> 37 38 #include <asm/debugfs.h> 39 #include <asm/page.h> 40 #include <asm/prom.h> 41 #include <asm/rtas.h> 42 #include <asm/fadump.h> 43 #include <asm/setup.h> 44 45 static struct fw_dump fw_dump; 46 static struct fadump_mem_struct fdm; 47 static const struct fadump_mem_struct *fdm_active; 48 49 static DEFINE_MUTEX(fadump_mutex); 50 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES]; 51 int crash_mem_ranges; 52 53 /* Scan the Firmware Assisted dump configuration details. */ 54 int __init early_init_dt_scan_fw_dump(unsigned long node, 55 const char *uname, int depth, void *data) 56 { 57 const __be32 *sections; 58 int i, num_sections; 59 int size; 60 const __be32 *token; 61 62 if (depth != 1 || strcmp(uname, "rtas") != 0) 63 return 0; 64 65 /* 66 * Check if Firmware Assisted dump is supported. if yes, check 67 * if dump has been initiated on last reboot. 68 */ 69 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 70 if (!token) 71 return 1; 72 73 fw_dump.fadump_supported = 1; 74 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 75 76 /* 77 * The 'ibm,kernel-dump' rtas node is present only if there is 78 * dump data waiting for us. 79 */ 80 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 81 if (fdm_active) 82 fw_dump.dump_active = 1; 83 84 /* Get the sizes required to store dump data for the firmware provided 85 * dump sections. 86 * For each dump section type supported, a 32bit cell which defines 87 * the ID of a supported section followed by two 32 bit cells which 88 * gives teh size of the section in bytes. 89 */ 90 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 91 &size); 92 93 if (!sections) 94 return 1; 95 96 num_sections = size / (3 * sizeof(u32)); 97 98 for (i = 0; i < num_sections; i++, sections += 3) { 99 u32 type = (u32)of_read_number(sections, 1); 100 101 switch (type) { 102 case FADUMP_CPU_STATE_DATA: 103 fw_dump.cpu_state_data_size = 104 of_read_ulong(§ions[1], 2); 105 break; 106 case FADUMP_HPTE_REGION: 107 fw_dump.hpte_region_size = 108 of_read_ulong(§ions[1], 2); 109 break; 110 } 111 } 112 113 return 1; 114 } 115 116 /* 117 * If fadump is registered, check if the memory provided 118 * falls within boot memory area. 119 */ 120 int is_fadump_boot_memory_area(u64 addr, ulong size) 121 { 122 if (!fw_dump.dump_registered) 123 return 0; 124 125 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; 126 } 127 128 int should_fadump_crash(void) 129 { 130 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 131 return 0; 132 return 1; 133 } 134 135 int is_fadump_active(void) 136 { 137 return fw_dump.dump_active; 138 } 139 140 /* 141 * Returns 1, if there are no holes in boot memory area, 142 * 0 otherwise. 143 */ 144 static int is_boot_memory_area_contiguous(void) 145 { 146 struct memblock_region *reg; 147 unsigned long tstart, tend; 148 unsigned long start_pfn = PHYS_PFN(RMA_START); 149 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size); 150 unsigned int ret = 0; 151 152 for_each_memblock(memory, reg) { 153 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 154 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 155 if (tstart < tend) { 156 /* Memory hole from start_pfn to tstart */ 157 if (tstart > start_pfn) 158 break; 159 160 if (tend == end_pfn) { 161 ret = 1; 162 break; 163 } 164 165 start_pfn = tend + 1; 166 } 167 } 168 169 return ret; 170 } 171 172 /* Print firmware assisted dump configurations for debugging purpose. */ 173 static void fadump_show_config(void) 174 { 175 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 176 (fw_dump.fadump_supported ? "present" : "no support")); 177 178 if (!fw_dump.fadump_supported) 179 return; 180 181 pr_debug("Fadump enabled : %s\n", 182 (fw_dump.fadump_enabled ? "yes" : "no")); 183 pr_debug("Dump Active : %s\n", 184 (fw_dump.dump_active ? "yes" : "no")); 185 pr_debug("Dump section sizes:\n"); 186 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 187 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 188 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 189 } 190 191 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 192 unsigned long addr) 193 { 194 if (!fdm) 195 return 0; 196 197 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 198 addr = addr & PAGE_MASK; 199 200 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 201 fdm->header.dump_num_sections = cpu_to_be16(3); 202 fdm->header.dump_status_flag = 0; 203 fdm->header.offset_first_dump_section = 204 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 205 206 /* 207 * Fields for disk dump option. 208 * We are not using disk dump option, hence set these fields to 0. 209 */ 210 fdm->header.dd_block_size = 0; 211 fdm->header.dd_block_offset = 0; 212 fdm->header.dd_num_blocks = 0; 213 fdm->header.dd_offset_disk_path = 0; 214 215 /* set 0 to disable an automatic dump-reboot. */ 216 fdm->header.max_time_auto = 0; 217 218 /* Kernel dump sections */ 219 /* cpu state data section. */ 220 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 221 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 222 fdm->cpu_state_data.source_address = 0; 223 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 224 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 225 addr += fw_dump.cpu_state_data_size; 226 227 /* hpte region section */ 228 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 229 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 230 fdm->hpte_region.source_address = 0; 231 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 232 fdm->hpte_region.destination_address = cpu_to_be64(addr); 233 addr += fw_dump.hpte_region_size; 234 235 /* RMA region section */ 236 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 237 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 238 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 239 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 240 fdm->rmr_region.destination_address = cpu_to_be64(addr); 241 addr += fw_dump.boot_memory_size; 242 243 return addr; 244 } 245 246 /** 247 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 248 * 249 * Function to find the largest memory size we need to reserve during early 250 * boot process. This will be the size of the memory that is required for a 251 * kernel to boot successfully. 252 * 253 * This function has been taken from phyp-assisted dump feature implementation. 254 * 255 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 256 * 257 * TODO: Come up with better approach to find out more accurate memory size 258 * that is required for a kernel to boot successfully. 259 * 260 */ 261 static inline unsigned long fadump_calculate_reserve_size(void) 262 { 263 int ret; 264 unsigned long long base, size; 265 266 if (fw_dump.reserve_bootvar) 267 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 268 269 /* 270 * Check if the size is specified through crashkernel= cmdline 271 * option. If yes, then use that but ignore base as fadump reserves 272 * memory at a predefined offset. 273 */ 274 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 275 &size, &base); 276 if (ret == 0 && size > 0) { 277 unsigned long max_size; 278 279 if (fw_dump.reserve_bootvar) 280 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 281 282 fw_dump.reserve_bootvar = (unsigned long)size; 283 284 /* 285 * Adjust if the boot memory size specified is above 286 * the upper limit. 287 */ 288 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 289 if (fw_dump.reserve_bootvar > max_size) { 290 fw_dump.reserve_bootvar = max_size; 291 pr_info("Adjusted boot memory size to %luMB\n", 292 (fw_dump.reserve_bootvar >> 20)); 293 } 294 295 return fw_dump.reserve_bootvar; 296 } else if (fw_dump.reserve_bootvar) { 297 /* 298 * 'fadump_reserve_mem=' is being used to reserve memory 299 * for firmware-assisted dump. 300 */ 301 return fw_dump.reserve_bootvar; 302 } 303 304 /* divide by 20 to get 5% of value */ 305 size = memblock_phys_mem_size() / 20; 306 307 /* round it down in multiples of 256 */ 308 size = size & ~0x0FFFFFFFUL; 309 310 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 311 if (memory_limit && size > memory_limit) 312 size = memory_limit; 313 314 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 315 } 316 317 /* 318 * Calculate the total memory size required to be reserved for 319 * firmware-assisted dump registration. 320 */ 321 static unsigned long get_fadump_area_size(void) 322 { 323 unsigned long size = 0; 324 325 size += fw_dump.cpu_state_data_size; 326 size += fw_dump.hpte_region_size; 327 size += fw_dump.boot_memory_size; 328 size += sizeof(struct fadump_crash_info_header); 329 size += sizeof(struct elfhdr); /* ELF core header.*/ 330 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 331 /* Program headers for crash memory regions. */ 332 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 333 334 size = PAGE_ALIGN(size); 335 return size; 336 } 337 338 static void __init fadump_reserve_crash_area(unsigned long base, 339 unsigned long size) 340 { 341 struct memblock_region *reg; 342 unsigned long mstart, mend, msize; 343 344 for_each_memblock(memory, reg) { 345 mstart = max_t(unsigned long, base, reg->base); 346 mend = reg->base + reg->size; 347 mend = min(base + size, mend); 348 349 if (mstart < mend) { 350 msize = mend - mstart; 351 memblock_reserve(mstart, msize); 352 pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n", 353 (msize >> 20), mstart); 354 } 355 } 356 } 357 358 int __init fadump_reserve_mem(void) 359 { 360 unsigned long base, size, memory_boundary; 361 362 if (!fw_dump.fadump_enabled) 363 return 0; 364 365 if (!fw_dump.fadump_supported) { 366 printk(KERN_INFO "Firmware-assisted dump is not supported on" 367 " this hardware\n"); 368 fw_dump.fadump_enabled = 0; 369 return 0; 370 } 371 /* 372 * Initialize boot memory size 373 * If dump is active then we have already calculated the size during 374 * first kernel. 375 */ 376 if (fdm_active) 377 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 378 else 379 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 380 381 /* 382 * Calculate the memory boundary. 383 * If memory_limit is less than actual memory boundary then reserve 384 * the memory for fadump beyond the memory_limit and adjust the 385 * memory_limit accordingly, so that the running kernel can run with 386 * specified memory_limit. 387 */ 388 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 389 size = get_fadump_area_size(); 390 if ((memory_limit + size) < memblock_end_of_DRAM()) 391 memory_limit += size; 392 else 393 memory_limit = memblock_end_of_DRAM(); 394 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 395 " dump, now %#016llx\n", memory_limit); 396 } 397 if (memory_limit) 398 memory_boundary = memory_limit; 399 else 400 memory_boundary = memblock_end_of_DRAM(); 401 402 if (fw_dump.dump_active) { 403 pr_info("Firmware-assisted dump is active.\n"); 404 405 /* 406 * If last boot has crashed then reserve all the memory 407 * above boot_memory_size so that we don't touch it until 408 * dump is written to disk by userspace tool. This memory 409 * will be released for general use once the dump is saved. 410 */ 411 base = fw_dump.boot_memory_size; 412 size = memory_boundary - base; 413 fadump_reserve_crash_area(base, size); 414 415 fw_dump.fadumphdr_addr = 416 be64_to_cpu(fdm_active->rmr_region.destination_address) + 417 be64_to_cpu(fdm_active->rmr_region.source_len); 418 pr_debug("fadumphdr_addr = %p\n", 419 (void *) fw_dump.fadumphdr_addr); 420 } else { 421 size = get_fadump_area_size(); 422 423 /* 424 * Reserve memory at an offset closer to bottom of the RAM to 425 * minimize the impact of memory hot-remove operation. We can't 426 * use memblock_find_in_range() here since it doesn't allocate 427 * from bottom to top. 428 */ 429 for (base = fw_dump.boot_memory_size; 430 base <= (memory_boundary - size); 431 base += size) { 432 if (memblock_is_region_memory(base, size) && 433 !memblock_is_region_reserved(base, size)) 434 break; 435 } 436 if ((base > (memory_boundary - size)) || 437 memblock_reserve(base, size)) { 438 pr_err("Failed to reserve memory\n"); 439 return 0; 440 } 441 442 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 443 "assisted dump (System RAM: %ldMB)\n", 444 (unsigned long)(size >> 20), 445 (unsigned long)(base >> 20), 446 (unsigned long)(memblock_phys_mem_size() >> 20)); 447 } 448 449 fw_dump.reserve_dump_area_start = base; 450 fw_dump.reserve_dump_area_size = size; 451 return 1; 452 } 453 454 unsigned long __init arch_reserved_kernel_pages(void) 455 { 456 return memblock_reserved_size() / PAGE_SIZE; 457 } 458 459 /* Look for fadump= cmdline option. */ 460 static int __init early_fadump_param(char *p) 461 { 462 if (!p) 463 return 1; 464 465 if (strncmp(p, "on", 2) == 0) 466 fw_dump.fadump_enabled = 1; 467 else if (strncmp(p, "off", 3) == 0) 468 fw_dump.fadump_enabled = 0; 469 470 return 0; 471 } 472 early_param("fadump", early_fadump_param); 473 474 /* 475 * Look for fadump_reserve_mem= cmdline option 476 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 477 * the sooner 'crashkernel=' parameter is accustomed to. 478 */ 479 static int __init early_fadump_reserve_mem(char *p) 480 { 481 if (p) 482 fw_dump.reserve_bootvar = memparse(p, &p); 483 return 0; 484 } 485 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 486 487 static int register_fw_dump(struct fadump_mem_struct *fdm) 488 { 489 int rc, err; 490 unsigned int wait_time; 491 492 pr_debug("Registering for firmware-assisted kernel dump...\n"); 493 494 /* TODO: Add upper time limit for the delay */ 495 do { 496 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 497 FADUMP_REGISTER, fdm, 498 sizeof(struct fadump_mem_struct)); 499 500 wait_time = rtas_busy_delay_time(rc); 501 if (wait_time) 502 mdelay(wait_time); 503 504 } while (wait_time); 505 506 err = -EIO; 507 switch (rc) { 508 default: 509 pr_err("Failed to register. Unknown Error(%d).\n", rc); 510 break; 511 case -1: 512 printk(KERN_ERR "Failed to register firmware-assisted kernel" 513 " dump. Hardware Error(%d).\n", rc); 514 break; 515 case -3: 516 if (!is_boot_memory_area_contiguous()) 517 pr_err("Can't have holes in boot memory area while " 518 "registering fadump\n"); 519 520 printk(KERN_ERR "Failed to register firmware-assisted kernel" 521 " dump. Parameter Error(%d).\n", rc); 522 err = -EINVAL; 523 break; 524 case -9: 525 printk(KERN_ERR "firmware-assisted kernel dump is already " 526 " registered."); 527 fw_dump.dump_registered = 1; 528 err = -EEXIST; 529 break; 530 case 0: 531 printk(KERN_INFO "firmware-assisted kernel dump registration" 532 " is successful\n"); 533 fw_dump.dump_registered = 1; 534 err = 0; 535 break; 536 } 537 return err; 538 } 539 540 void crash_fadump(struct pt_regs *regs, const char *str) 541 { 542 struct fadump_crash_info_header *fdh = NULL; 543 int old_cpu, this_cpu; 544 545 if (!should_fadump_crash()) 546 return; 547 548 /* 549 * old_cpu == -1 means this is the first CPU which has come here, 550 * go ahead and trigger fadump. 551 * 552 * old_cpu != -1 means some other CPU has already on it's way 553 * to trigger fadump, just keep looping here. 554 */ 555 this_cpu = smp_processor_id(); 556 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 557 558 if (old_cpu != -1) { 559 /* 560 * We can't loop here indefinitely. Wait as long as fadump 561 * is in force. If we race with fadump un-registration this 562 * loop will break and then we go down to normal panic path 563 * and reboot. If fadump is in force the first crashing 564 * cpu will definitely trigger fadump. 565 */ 566 while (fw_dump.dump_registered) 567 cpu_relax(); 568 return; 569 } 570 571 fdh = __va(fw_dump.fadumphdr_addr); 572 fdh->crashing_cpu = crashing_cpu; 573 crash_save_vmcoreinfo(); 574 575 if (regs) 576 fdh->regs = *regs; 577 else 578 ppc_save_regs(&fdh->regs); 579 580 fdh->online_mask = *cpu_online_mask; 581 582 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 583 rtas_os_term((char *)str); 584 } 585 586 #define GPR_MASK 0xffffff0000000000 587 static inline int fadump_gpr_index(u64 id) 588 { 589 int i = -1; 590 char str[3]; 591 592 if ((id & GPR_MASK) == REG_ID("GPR")) { 593 /* get the digits at the end */ 594 id &= ~GPR_MASK; 595 id >>= 24; 596 str[2] = '\0'; 597 str[1] = id & 0xff; 598 str[0] = (id >> 8) & 0xff; 599 sscanf(str, "%d", &i); 600 if (i > 31) 601 i = -1; 602 } 603 return i; 604 } 605 606 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 607 u64 reg_val) 608 { 609 int i; 610 611 i = fadump_gpr_index(reg_id); 612 if (i >= 0) 613 regs->gpr[i] = (unsigned long)reg_val; 614 else if (reg_id == REG_ID("NIA")) 615 regs->nip = (unsigned long)reg_val; 616 else if (reg_id == REG_ID("MSR")) 617 regs->msr = (unsigned long)reg_val; 618 else if (reg_id == REG_ID("CTR")) 619 regs->ctr = (unsigned long)reg_val; 620 else if (reg_id == REG_ID("LR")) 621 regs->link = (unsigned long)reg_val; 622 else if (reg_id == REG_ID("XER")) 623 regs->xer = (unsigned long)reg_val; 624 else if (reg_id == REG_ID("CR")) 625 regs->ccr = (unsigned long)reg_val; 626 else if (reg_id == REG_ID("DAR")) 627 regs->dar = (unsigned long)reg_val; 628 else if (reg_id == REG_ID("DSISR")) 629 regs->dsisr = (unsigned long)reg_val; 630 } 631 632 static struct fadump_reg_entry* 633 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 634 { 635 memset(regs, 0, sizeof(struct pt_regs)); 636 637 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 638 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 639 be64_to_cpu(reg_entry->reg_value)); 640 reg_entry++; 641 } 642 reg_entry++; 643 return reg_entry; 644 } 645 646 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 647 { 648 struct elf_prstatus prstatus; 649 650 memset(&prstatus, 0, sizeof(prstatus)); 651 /* 652 * FIXME: How do i get PID? Do I really need it? 653 * prstatus.pr_pid = ???? 654 */ 655 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 656 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 657 &prstatus, sizeof(prstatus)); 658 return buf; 659 } 660 661 static void fadump_update_elfcore_header(char *bufp) 662 { 663 struct elfhdr *elf; 664 struct elf_phdr *phdr; 665 666 elf = (struct elfhdr *)bufp; 667 bufp += sizeof(struct elfhdr); 668 669 /* First note is a place holder for cpu notes info. */ 670 phdr = (struct elf_phdr *)bufp; 671 672 if (phdr->p_type == PT_NOTE) { 673 phdr->p_paddr = fw_dump.cpu_notes_buf; 674 phdr->p_offset = phdr->p_paddr; 675 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 676 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 677 } 678 return; 679 } 680 681 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 682 { 683 void *vaddr; 684 struct page *page; 685 unsigned long order, count, i; 686 687 order = get_order(size); 688 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 689 if (!vaddr) 690 return NULL; 691 692 count = 1 << order; 693 page = virt_to_page(vaddr); 694 for (i = 0; i < count; i++) 695 SetPageReserved(page + i); 696 return vaddr; 697 } 698 699 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 700 { 701 struct page *page; 702 unsigned long order, count, i; 703 704 order = get_order(size); 705 count = 1 << order; 706 page = virt_to_page(vaddr); 707 for (i = 0; i < count; i++) 708 ClearPageReserved(page + i); 709 __free_pages(page, order); 710 } 711 712 /* 713 * Read CPU state dump data and convert it into ELF notes. 714 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 715 * used to access the data to allow for additional fields to be added without 716 * affecting compatibility. Each list of registers for a CPU starts with 717 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 718 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 719 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 720 * of register value. For more details refer to PAPR document. 721 * 722 * Only for the crashing cpu we ignore the CPU dump data and get exact 723 * state from fadump crash info structure populated by first kernel at the 724 * time of crash. 725 */ 726 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 727 { 728 struct fadump_reg_save_area_header *reg_header; 729 struct fadump_reg_entry *reg_entry; 730 struct fadump_crash_info_header *fdh = NULL; 731 void *vaddr; 732 unsigned long addr; 733 u32 num_cpus, *note_buf; 734 struct pt_regs regs; 735 int i, rc = 0, cpu = 0; 736 737 if (!fdm->cpu_state_data.bytes_dumped) 738 return -EINVAL; 739 740 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 741 vaddr = __va(addr); 742 743 reg_header = vaddr; 744 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 745 printk(KERN_ERR "Unable to read register save area.\n"); 746 return -ENOENT; 747 } 748 pr_debug("--------CPU State Data------------\n"); 749 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 750 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 751 752 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 753 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 754 pr_debug("NumCpus : %u\n", num_cpus); 755 vaddr += sizeof(u32); 756 reg_entry = (struct fadump_reg_entry *)vaddr; 757 758 /* Allocate buffer to hold cpu crash notes. */ 759 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 760 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 761 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 762 if (!note_buf) { 763 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 764 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 765 return -ENOMEM; 766 } 767 fw_dump.cpu_notes_buf = __pa(note_buf); 768 769 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 770 (num_cpus * sizeof(note_buf_t)), note_buf); 771 772 if (fw_dump.fadumphdr_addr) 773 fdh = __va(fw_dump.fadumphdr_addr); 774 775 for (i = 0; i < num_cpus; i++) { 776 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 777 printk(KERN_ERR "Unable to read CPU state data\n"); 778 rc = -ENOENT; 779 goto error_out; 780 } 781 /* Lower 4 bytes of reg_value contains logical cpu id */ 782 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 783 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 784 SKIP_TO_NEXT_CPU(reg_entry); 785 continue; 786 } 787 pr_debug("Reading register data for cpu %d...\n", cpu); 788 if (fdh && fdh->crashing_cpu == cpu) { 789 regs = fdh->regs; 790 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 791 SKIP_TO_NEXT_CPU(reg_entry); 792 } else { 793 reg_entry++; 794 reg_entry = fadump_read_registers(reg_entry, ®s); 795 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 796 } 797 } 798 final_note(note_buf); 799 800 if (fdh) { 801 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 802 fdh->elfcorehdr_addr); 803 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 804 } 805 return 0; 806 807 error_out: 808 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 809 fw_dump.cpu_notes_buf_size); 810 fw_dump.cpu_notes_buf = 0; 811 fw_dump.cpu_notes_buf_size = 0; 812 return rc; 813 814 } 815 816 /* 817 * Validate and process the dump data stored by firmware before exporting 818 * it through '/proc/vmcore'. 819 */ 820 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 821 { 822 struct fadump_crash_info_header *fdh; 823 int rc = 0; 824 825 if (!fdm_active || !fw_dump.fadumphdr_addr) 826 return -EINVAL; 827 828 /* Check if the dump data is valid. */ 829 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 830 (fdm_active->cpu_state_data.error_flags != 0) || 831 (fdm_active->rmr_region.error_flags != 0)) { 832 printk(KERN_ERR "Dump taken by platform is not valid\n"); 833 return -EINVAL; 834 } 835 if ((fdm_active->rmr_region.bytes_dumped != 836 fdm_active->rmr_region.source_len) || 837 !fdm_active->cpu_state_data.bytes_dumped) { 838 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 839 return -EINVAL; 840 } 841 842 /* Validate the fadump crash info header */ 843 fdh = __va(fw_dump.fadumphdr_addr); 844 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 845 printk(KERN_ERR "Crash info header is not valid.\n"); 846 return -EINVAL; 847 } 848 849 rc = fadump_build_cpu_notes(fdm_active); 850 if (rc) 851 return rc; 852 853 /* 854 * We are done validating dump info and elfcore header is now ready 855 * to be exported. set elfcorehdr_addr so that vmcore module will 856 * export the elfcore header through '/proc/vmcore'. 857 */ 858 elfcorehdr_addr = fdh->elfcorehdr_addr; 859 860 return 0; 861 } 862 863 static inline void fadump_add_crash_memory(unsigned long long base, 864 unsigned long long end) 865 { 866 if (base == end) 867 return; 868 869 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 870 crash_mem_ranges, base, end - 1, (end - base)); 871 crash_memory_ranges[crash_mem_ranges].base = base; 872 crash_memory_ranges[crash_mem_ranges].size = end - base; 873 crash_mem_ranges++; 874 } 875 876 static void fadump_exclude_reserved_area(unsigned long long start, 877 unsigned long long end) 878 { 879 unsigned long long ra_start, ra_end; 880 881 ra_start = fw_dump.reserve_dump_area_start; 882 ra_end = ra_start + fw_dump.reserve_dump_area_size; 883 884 if ((ra_start < end) && (ra_end > start)) { 885 if ((start < ra_start) && (end > ra_end)) { 886 fadump_add_crash_memory(start, ra_start); 887 fadump_add_crash_memory(ra_end, end); 888 } else if (start < ra_start) { 889 fadump_add_crash_memory(start, ra_start); 890 } else if (ra_end < end) { 891 fadump_add_crash_memory(ra_end, end); 892 } 893 } else 894 fadump_add_crash_memory(start, end); 895 } 896 897 static int fadump_init_elfcore_header(char *bufp) 898 { 899 struct elfhdr *elf; 900 901 elf = (struct elfhdr *) bufp; 902 bufp += sizeof(struct elfhdr); 903 memcpy(elf->e_ident, ELFMAG, SELFMAG); 904 elf->e_ident[EI_CLASS] = ELF_CLASS; 905 elf->e_ident[EI_DATA] = ELF_DATA; 906 elf->e_ident[EI_VERSION] = EV_CURRENT; 907 elf->e_ident[EI_OSABI] = ELF_OSABI; 908 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 909 elf->e_type = ET_CORE; 910 elf->e_machine = ELF_ARCH; 911 elf->e_version = EV_CURRENT; 912 elf->e_entry = 0; 913 elf->e_phoff = sizeof(struct elfhdr); 914 elf->e_shoff = 0; 915 #if defined(_CALL_ELF) 916 elf->e_flags = _CALL_ELF; 917 #else 918 elf->e_flags = 0; 919 #endif 920 elf->e_ehsize = sizeof(struct elfhdr); 921 elf->e_phentsize = sizeof(struct elf_phdr); 922 elf->e_phnum = 0; 923 elf->e_shentsize = 0; 924 elf->e_shnum = 0; 925 elf->e_shstrndx = 0; 926 927 return 0; 928 } 929 930 /* 931 * Traverse through memblock structure and setup crash memory ranges. These 932 * ranges will be used create PT_LOAD program headers in elfcore header. 933 */ 934 static void fadump_setup_crash_memory_ranges(void) 935 { 936 struct memblock_region *reg; 937 unsigned long long start, end; 938 939 pr_debug("Setup crash memory ranges.\n"); 940 crash_mem_ranges = 0; 941 /* 942 * add the first memory chunk (RMA_START through boot_memory_size) as 943 * a separate memory chunk. The reason is, at the time crash firmware 944 * will move the content of this memory chunk to different location 945 * specified during fadump registration. We need to create a separate 946 * program header for this chunk with the correct offset. 947 */ 948 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 949 950 for_each_memblock(memory, reg) { 951 start = (unsigned long long)reg->base; 952 end = start + (unsigned long long)reg->size; 953 954 /* 955 * skip the first memory chunk that is already added (RMA_START 956 * through boot_memory_size). This logic needs a relook if and 957 * when RMA_START changes to a non-zero value. 958 */ 959 BUILD_BUG_ON(RMA_START != 0); 960 if (start < fw_dump.boot_memory_size) { 961 if (end > fw_dump.boot_memory_size) 962 start = fw_dump.boot_memory_size; 963 else 964 continue; 965 } 966 967 /* add this range excluding the reserved dump area. */ 968 fadump_exclude_reserved_area(start, end); 969 } 970 } 971 972 /* 973 * If the given physical address falls within the boot memory region then 974 * return the relocated address that points to the dump region reserved 975 * for saving initial boot memory contents. 976 */ 977 static inline unsigned long fadump_relocate(unsigned long paddr) 978 { 979 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 980 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 981 else 982 return paddr; 983 } 984 985 static int fadump_create_elfcore_headers(char *bufp) 986 { 987 struct elfhdr *elf; 988 struct elf_phdr *phdr; 989 int i; 990 991 fadump_init_elfcore_header(bufp); 992 elf = (struct elfhdr *)bufp; 993 bufp += sizeof(struct elfhdr); 994 995 /* 996 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 997 * will be populated during second kernel boot after crash. Hence 998 * this PT_NOTE will always be the first elf note. 999 * 1000 * NOTE: Any new ELF note addition should be placed after this note. 1001 */ 1002 phdr = (struct elf_phdr *)bufp; 1003 bufp += sizeof(struct elf_phdr); 1004 phdr->p_type = PT_NOTE; 1005 phdr->p_flags = 0; 1006 phdr->p_vaddr = 0; 1007 phdr->p_align = 0; 1008 1009 phdr->p_offset = 0; 1010 phdr->p_paddr = 0; 1011 phdr->p_filesz = 0; 1012 phdr->p_memsz = 0; 1013 1014 (elf->e_phnum)++; 1015 1016 /* setup ELF PT_NOTE for vmcoreinfo */ 1017 phdr = (struct elf_phdr *)bufp; 1018 bufp += sizeof(struct elf_phdr); 1019 phdr->p_type = PT_NOTE; 1020 phdr->p_flags = 0; 1021 phdr->p_vaddr = 0; 1022 phdr->p_align = 0; 1023 1024 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1025 phdr->p_offset = phdr->p_paddr; 1026 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1027 1028 /* Increment number of program headers. */ 1029 (elf->e_phnum)++; 1030 1031 /* setup PT_LOAD sections. */ 1032 1033 for (i = 0; i < crash_mem_ranges; i++) { 1034 unsigned long long mbase, msize; 1035 mbase = crash_memory_ranges[i].base; 1036 msize = crash_memory_ranges[i].size; 1037 1038 if (!msize) 1039 continue; 1040 1041 phdr = (struct elf_phdr *)bufp; 1042 bufp += sizeof(struct elf_phdr); 1043 phdr->p_type = PT_LOAD; 1044 phdr->p_flags = PF_R|PF_W|PF_X; 1045 phdr->p_offset = mbase; 1046 1047 if (mbase == RMA_START) { 1048 /* 1049 * The entire RMA region will be moved by firmware 1050 * to the specified destination_address. Hence set 1051 * the correct offset. 1052 */ 1053 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1054 } 1055 1056 phdr->p_paddr = mbase; 1057 phdr->p_vaddr = (unsigned long)__va(mbase); 1058 phdr->p_filesz = msize; 1059 phdr->p_memsz = msize; 1060 phdr->p_align = 0; 1061 1062 /* Increment number of program headers. */ 1063 (elf->e_phnum)++; 1064 } 1065 return 0; 1066 } 1067 1068 static unsigned long init_fadump_header(unsigned long addr) 1069 { 1070 struct fadump_crash_info_header *fdh; 1071 1072 if (!addr) 1073 return 0; 1074 1075 fw_dump.fadumphdr_addr = addr; 1076 fdh = __va(addr); 1077 addr += sizeof(struct fadump_crash_info_header); 1078 1079 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1080 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1081 fdh->elfcorehdr_addr = addr; 1082 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1083 fdh->crashing_cpu = CPU_UNKNOWN; 1084 1085 return addr; 1086 } 1087 1088 static int register_fadump(void) 1089 { 1090 unsigned long addr; 1091 void *vaddr; 1092 1093 /* 1094 * If no memory is reserved then we can not register for firmware- 1095 * assisted dump. 1096 */ 1097 if (!fw_dump.reserve_dump_area_size) 1098 return -ENODEV; 1099 1100 fadump_setup_crash_memory_ranges(); 1101 1102 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1103 /* Initialize fadump crash info header. */ 1104 addr = init_fadump_header(addr); 1105 vaddr = __va(addr); 1106 1107 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1108 fadump_create_elfcore_headers(vaddr); 1109 1110 /* register the future kernel dump with firmware. */ 1111 return register_fw_dump(&fdm); 1112 } 1113 1114 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1115 { 1116 int rc = 0; 1117 unsigned int wait_time; 1118 1119 pr_debug("Un-register firmware-assisted dump\n"); 1120 1121 /* TODO: Add upper time limit for the delay */ 1122 do { 1123 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1124 FADUMP_UNREGISTER, fdm, 1125 sizeof(struct fadump_mem_struct)); 1126 1127 wait_time = rtas_busy_delay_time(rc); 1128 if (wait_time) 1129 mdelay(wait_time); 1130 } while (wait_time); 1131 1132 if (rc) { 1133 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1134 " unexpected error(%d).\n", rc); 1135 return rc; 1136 } 1137 fw_dump.dump_registered = 0; 1138 return 0; 1139 } 1140 1141 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1142 { 1143 int rc = 0; 1144 unsigned int wait_time; 1145 1146 pr_debug("Invalidating firmware-assisted dump registration\n"); 1147 1148 /* TODO: Add upper time limit for the delay */ 1149 do { 1150 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1151 FADUMP_INVALIDATE, fdm, 1152 sizeof(struct fadump_mem_struct)); 1153 1154 wait_time = rtas_busy_delay_time(rc); 1155 if (wait_time) 1156 mdelay(wait_time); 1157 } while (wait_time); 1158 1159 if (rc) { 1160 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1161 return rc; 1162 } 1163 fw_dump.dump_active = 0; 1164 fdm_active = NULL; 1165 return 0; 1166 } 1167 1168 void fadump_cleanup(void) 1169 { 1170 /* Invalidate the registration only if dump is active. */ 1171 if (fw_dump.dump_active) { 1172 init_fadump_mem_struct(&fdm, 1173 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1174 fadump_invalidate_dump(&fdm); 1175 } 1176 } 1177 1178 static void fadump_free_reserved_memory(unsigned long start_pfn, 1179 unsigned long end_pfn) 1180 { 1181 unsigned long pfn; 1182 unsigned long time_limit = jiffies + HZ; 1183 1184 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1185 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1186 1187 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1188 free_reserved_page(pfn_to_page(pfn)); 1189 1190 if (time_after(jiffies, time_limit)) { 1191 cond_resched(); 1192 time_limit = jiffies + HZ; 1193 } 1194 } 1195 } 1196 1197 /* 1198 * Skip memory holes and free memory that was actually reserved. 1199 */ 1200 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1201 { 1202 struct memblock_region *reg; 1203 unsigned long tstart, tend; 1204 unsigned long start_pfn = PHYS_PFN(start); 1205 unsigned long end_pfn = PHYS_PFN(end); 1206 1207 for_each_memblock(memory, reg) { 1208 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1209 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1210 if (tstart < tend) { 1211 fadump_free_reserved_memory(tstart, tend); 1212 1213 if (tend == end_pfn) 1214 break; 1215 1216 start_pfn = tend + 1; 1217 } 1218 } 1219 } 1220 1221 /* 1222 * Release the memory that was reserved in early boot to preserve the memory 1223 * contents. The released memory will be available for general use. 1224 */ 1225 static void fadump_release_memory(unsigned long begin, unsigned long end) 1226 { 1227 unsigned long ra_start, ra_end; 1228 1229 ra_start = fw_dump.reserve_dump_area_start; 1230 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1231 1232 /* 1233 * exclude the dump reserve area. Will reuse it for next 1234 * fadump registration. 1235 */ 1236 if (begin < ra_end && end > ra_start) { 1237 if (begin < ra_start) 1238 fadump_release_reserved_area(begin, ra_start); 1239 if (end > ra_end) 1240 fadump_release_reserved_area(ra_end, end); 1241 } else 1242 fadump_release_reserved_area(begin, end); 1243 } 1244 1245 static void fadump_invalidate_release_mem(void) 1246 { 1247 unsigned long reserved_area_start, reserved_area_end; 1248 unsigned long destination_address; 1249 1250 mutex_lock(&fadump_mutex); 1251 if (!fw_dump.dump_active) { 1252 mutex_unlock(&fadump_mutex); 1253 return; 1254 } 1255 1256 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1257 fadump_cleanup(); 1258 mutex_unlock(&fadump_mutex); 1259 1260 /* 1261 * Save the current reserved memory bounds we will require them 1262 * later for releasing the memory for general use. 1263 */ 1264 reserved_area_start = fw_dump.reserve_dump_area_start; 1265 reserved_area_end = reserved_area_start + 1266 fw_dump.reserve_dump_area_size; 1267 /* 1268 * Setup reserve_dump_area_start and its size so that we can 1269 * reuse this reserved memory for Re-registration. 1270 */ 1271 fw_dump.reserve_dump_area_start = destination_address; 1272 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1273 1274 fadump_release_memory(reserved_area_start, reserved_area_end); 1275 if (fw_dump.cpu_notes_buf) { 1276 fadump_cpu_notes_buf_free( 1277 (unsigned long)__va(fw_dump.cpu_notes_buf), 1278 fw_dump.cpu_notes_buf_size); 1279 fw_dump.cpu_notes_buf = 0; 1280 fw_dump.cpu_notes_buf_size = 0; 1281 } 1282 /* Initialize the kernel dump memory structure for FAD registration. */ 1283 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1284 } 1285 1286 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1287 struct kobj_attribute *attr, 1288 const char *buf, size_t count) 1289 { 1290 int input = -1; 1291 1292 if (!fw_dump.dump_active) 1293 return -EPERM; 1294 1295 if (kstrtoint(buf, 0, &input)) 1296 return -EINVAL; 1297 1298 if (input == 1) { 1299 /* 1300 * Take away the '/proc/vmcore'. We are releasing the dump 1301 * memory, hence it will not be valid anymore. 1302 */ 1303 #ifdef CONFIG_PROC_VMCORE 1304 vmcore_cleanup(); 1305 #endif 1306 fadump_invalidate_release_mem(); 1307 1308 } else 1309 return -EINVAL; 1310 return count; 1311 } 1312 1313 static ssize_t fadump_enabled_show(struct kobject *kobj, 1314 struct kobj_attribute *attr, 1315 char *buf) 1316 { 1317 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1318 } 1319 1320 static ssize_t fadump_register_show(struct kobject *kobj, 1321 struct kobj_attribute *attr, 1322 char *buf) 1323 { 1324 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1325 } 1326 1327 static ssize_t fadump_register_store(struct kobject *kobj, 1328 struct kobj_attribute *attr, 1329 const char *buf, size_t count) 1330 { 1331 int ret = 0; 1332 int input = -1; 1333 1334 if (!fw_dump.fadump_enabled || fdm_active) 1335 return -EPERM; 1336 1337 if (kstrtoint(buf, 0, &input)) 1338 return -EINVAL; 1339 1340 mutex_lock(&fadump_mutex); 1341 1342 switch (input) { 1343 case 0: 1344 if (fw_dump.dump_registered == 0) { 1345 goto unlock_out; 1346 } 1347 /* Un-register Firmware-assisted dump */ 1348 fadump_unregister_dump(&fdm); 1349 break; 1350 case 1: 1351 if (fw_dump.dump_registered == 1) { 1352 ret = -EEXIST; 1353 goto unlock_out; 1354 } 1355 /* Register Firmware-assisted dump */ 1356 ret = register_fadump(); 1357 break; 1358 default: 1359 ret = -EINVAL; 1360 break; 1361 } 1362 1363 unlock_out: 1364 mutex_unlock(&fadump_mutex); 1365 return ret < 0 ? ret : count; 1366 } 1367 1368 static int fadump_region_show(struct seq_file *m, void *private) 1369 { 1370 const struct fadump_mem_struct *fdm_ptr; 1371 1372 if (!fw_dump.fadump_enabled) 1373 return 0; 1374 1375 mutex_lock(&fadump_mutex); 1376 if (fdm_active) 1377 fdm_ptr = fdm_active; 1378 else { 1379 mutex_unlock(&fadump_mutex); 1380 fdm_ptr = &fdm; 1381 } 1382 1383 seq_printf(m, 1384 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1385 "Dumped: %#llx\n", 1386 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1387 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1388 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1389 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1390 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1391 seq_printf(m, 1392 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1393 "Dumped: %#llx\n", 1394 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1395 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1396 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1397 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1398 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1399 seq_printf(m, 1400 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1401 "Dumped: %#llx\n", 1402 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1403 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1404 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1405 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1406 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1407 1408 if (!fdm_active || 1409 (fw_dump.reserve_dump_area_start == 1410 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1411 goto out; 1412 1413 /* Dump is active. Show reserved memory region. */ 1414 seq_printf(m, 1415 " : [%#016llx-%#016llx] %#llx bytes, " 1416 "Dumped: %#llx\n", 1417 (unsigned long long)fw_dump.reserve_dump_area_start, 1418 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1419 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1420 fw_dump.reserve_dump_area_start, 1421 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1422 fw_dump.reserve_dump_area_start); 1423 out: 1424 if (fdm_active) 1425 mutex_unlock(&fadump_mutex); 1426 return 0; 1427 } 1428 1429 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1430 0200, NULL, 1431 fadump_release_memory_store); 1432 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1433 0444, fadump_enabled_show, 1434 NULL); 1435 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1436 0644, fadump_register_show, 1437 fadump_register_store); 1438 1439 static int fadump_region_open(struct inode *inode, struct file *file) 1440 { 1441 return single_open(file, fadump_region_show, inode->i_private); 1442 } 1443 1444 static const struct file_operations fadump_region_fops = { 1445 .open = fadump_region_open, 1446 .read = seq_read, 1447 .llseek = seq_lseek, 1448 .release = single_release, 1449 }; 1450 1451 static void fadump_init_files(void) 1452 { 1453 struct dentry *debugfs_file; 1454 int rc = 0; 1455 1456 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1457 if (rc) 1458 printk(KERN_ERR "fadump: unable to create sysfs file" 1459 " fadump_enabled (%d)\n", rc); 1460 1461 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1462 if (rc) 1463 printk(KERN_ERR "fadump: unable to create sysfs file" 1464 " fadump_registered (%d)\n", rc); 1465 1466 debugfs_file = debugfs_create_file("fadump_region", 0444, 1467 powerpc_debugfs_root, NULL, 1468 &fadump_region_fops); 1469 if (!debugfs_file) 1470 printk(KERN_ERR "fadump: unable to create debugfs file" 1471 " fadump_region\n"); 1472 1473 if (fw_dump.dump_active) { 1474 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1475 if (rc) 1476 printk(KERN_ERR "fadump: unable to create sysfs file" 1477 " fadump_release_mem (%d)\n", rc); 1478 } 1479 return; 1480 } 1481 1482 /* 1483 * Prepare for firmware-assisted dump. 1484 */ 1485 int __init setup_fadump(void) 1486 { 1487 if (!fw_dump.fadump_enabled) 1488 return 0; 1489 1490 if (!fw_dump.fadump_supported) { 1491 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1492 " this hardware\n"); 1493 return 0; 1494 } 1495 1496 fadump_show_config(); 1497 /* 1498 * If dump data is available then see if it is valid and prepare for 1499 * saving it to the disk. 1500 */ 1501 if (fw_dump.dump_active) { 1502 /* 1503 * if dump process fails then invalidate the registration 1504 * and release memory before proceeding for re-registration. 1505 */ 1506 if (process_fadump(fdm_active) < 0) 1507 fadump_invalidate_release_mem(); 1508 } 1509 /* Initialize the kernel dump memory structure for FAD registration. */ 1510 else if (fw_dump.reserve_dump_area_size) 1511 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1512 fadump_init_files(); 1513 1514 return 1; 1515 } 1516 subsys_initcall(setup_fadump); 1517