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 #ifdef CONFIG_HUGETLB_PAGE 406 /* 407 * FADump capture kernel doesn't care much about hugepages. 408 * In fact, handling hugepages in capture kernel is asking for 409 * trouble. So, disable HugeTLB support when fadump is active. 410 */ 411 hugetlb_disabled = true; 412 #endif 413 /* 414 * If last boot has crashed then reserve all the memory 415 * above boot_memory_size so that we don't touch it until 416 * dump is written to disk by userspace tool. This memory 417 * will be released for general use once the dump is saved. 418 */ 419 base = fw_dump.boot_memory_size; 420 size = memory_boundary - base; 421 fadump_reserve_crash_area(base, size); 422 423 fw_dump.fadumphdr_addr = 424 be64_to_cpu(fdm_active->rmr_region.destination_address) + 425 be64_to_cpu(fdm_active->rmr_region.source_len); 426 pr_debug("fadumphdr_addr = %p\n", 427 (void *) fw_dump.fadumphdr_addr); 428 } else { 429 size = get_fadump_area_size(); 430 431 /* 432 * Reserve memory at an offset closer to bottom of the RAM to 433 * minimize the impact of memory hot-remove operation. We can't 434 * use memblock_find_in_range() here since it doesn't allocate 435 * from bottom to top. 436 */ 437 for (base = fw_dump.boot_memory_size; 438 base <= (memory_boundary - size); 439 base += size) { 440 if (memblock_is_region_memory(base, size) && 441 !memblock_is_region_reserved(base, size)) 442 break; 443 } 444 if ((base > (memory_boundary - size)) || 445 memblock_reserve(base, size)) { 446 pr_err("Failed to reserve memory\n"); 447 return 0; 448 } 449 450 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 451 "assisted dump (System RAM: %ldMB)\n", 452 (unsigned long)(size >> 20), 453 (unsigned long)(base >> 20), 454 (unsigned long)(memblock_phys_mem_size() >> 20)); 455 } 456 457 fw_dump.reserve_dump_area_start = base; 458 fw_dump.reserve_dump_area_size = size; 459 return 1; 460 } 461 462 unsigned long __init arch_reserved_kernel_pages(void) 463 { 464 return memblock_reserved_size() / PAGE_SIZE; 465 } 466 467 /* Look for fadump= cmdline option. */ 468 static int __init early_fadump_param(char *p) 469 { 470 if (!p) 471 return 1; 472 473 if (strncmp(p, "on", 2) == 0) 474 fw_dump.fadump_enabled = 1; 475 else if (strncmp(p, "off", 3) == 0) 476 fw_dump.fadump_enabled = 0; 477 478 return 0; 479 } 480 early_param("fadump", early_fadump_param); 481 482 /* 483 * Look for fadump_reserve_mem= cmdline option 484 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 485 * the sooner 'crashkernel=' parameter is accustomed to. 486 */ 487 static int __init early_fadump_reserve_mem(char *p) 488 { 489 if (p) 490 fw_dump.reserve_bootvar = memparse(p, &p); 491 return 0; 492 } 493 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 494 495 static int register_fw_dump(struct fadump_mem_struct *fdm) 496 { 497 int rc, err; 498 unsigned int wait_time; 499 500 pr_debug("Registering for firmware-assisted kernel dump...\n"); 501 502 /* TODO: Add upper time limit for the delay */ 503 do { 504 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 505 FADUMP_REGISTER, fdm, 506 sizeof(struct fadump_mem_struct)); 507 508 wait_time = rtas_busy_delay_time(rc); 509 if (wait_time) 510 mdelay(wait_time); 511 512 } while (wait_time); 513 514 err = -EIO; 515 switch (rc) { 516 default: 517 pr_err("Failed to register. Unknown Error(%d).\n", rc); 518 break; 519 case -1: 520 printk(KERN_ERR "Failed to register firmware-assisted kernel" 521 " dump. Hardware Error(%d).\n", rc); 522 break; 523 case -3: 524 if (!is_boot_memory_area_contiguous()) 525 pr_err("Can't have holes in boot memory area while " 526 "registering fadump\n"); 527 528 printk(KERN_ERR "Failed to register firmware-assisted kernel" 529 " dump. Parameter Error(%d).\n", rc); 530 err = -EINVAL; 531 break; 532 case -9: 533 printk(KERN_ERR "firmware-assisted kernel dump is already " 534 " registered."); 535 fw_dump.dump_registered = 1; 536 err = -EEXIST; 537 break; 538 case 0: 539 printk(KERN_INFO "firmware-assisted kernel dump registration" 540 " is successful\n"); 541 fw_dump.dump_registered = 1; 542 err = 0; 543 break; 544 } 545 return err; 546 } 547 548 void crash_fadump(struct pt_regs *regs, const char *str) 549 { 550 struct fadump_crash_info_header *fdh = NULL; 551 int old_cpu, this_cpu; 552 553 if (!should_fadump_crash()) 554 return; 555 556 /* 557 * old_cpu == -1 means this is the first CPU which has come here, 558 * go ahead and trigger fadump. 559 * 560 * old_cpu != -1 means some other CPU has already on it's way 561 * to trigger fadump, just keep looping here. 562 */ 563 this_cpu = smp_processor_id(); 564 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 565 566 if (old_cpu != -1) { 567 /* 568 * We can't loop here indefinitely. Wait as long as fadump 569 * is in force. If we race with fadump un-registration this 570 * loop will break and then we go down to normal panic path 571 * and reboot. If fadump is in force the first crashing 572 * cpu will definitely trigger fadump. 573 */ 574 while (fw_dump.dump_registered) 575 cpu_relax(); 576 return; 577 } 578 579 fdh = __va(fw_dump.fadumphdr_addr); 580 fdh->crashing_cpu = crashing_cpu; 581 crash_save_vmcoreinfo(); 582 583 if (regs) 584 fdh->regs = *regs; 585 else 586 ppc_save_regs(&fdh->regs); 587 588 fdh->online_mask = *cpu_online_mask; 589 590 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 591 rtas_os_term((char *)str); 592 } 593 594 #define GPR_MASK 0xffffff0000000000 595 static inline int fadump_gpr_index(u64 id) 596 { 597 int i = -1; 598 char str[3]; 599 600 if ((id & GPR_MASK) == REG_ID("GPR")) { 601 /* get the digits at the end */ 602 id &= ~GPR_MASK; 603 id >>= 24; 604 str[2] = '\0'; 605 str[1] = id & 0xff; 606 str[0] = (id >> 8) & 0xff; 607 sscanf(str, "%d", &i); 608 if (i > 31) 609 i = -1; 610 } 611 return i; 612 } 613 614 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 615 u64 reg_val) 616 { 617 int i; 618 619 i = fadump_gpr_index(reg_id); 620 if (i >= 0) 621 regs->gpr[i] = (unsigned long)reg_val; 622 else if (reg_id == REG_ID("NIA")) 623 regs->nip = (unsigned long)reg_val; 624 else if (reg_id == REG_ID("MSR")) 625 regs->msr = (unsigned long)reg_val; 626 else if (reg_id == REG_ID("CTR")) 627 regs->ctr = (unsigned long)reg_val; 628 else if (reg_id == REG_ID("LR")) 629 regs->link = (unsigned long)reg_val; 630 else if (reg_id == REG_ID("XER")) 631 regs->xer = (unsigned long)reg_val; 632 else if (reg_id == REG_ID("CR")) 633 regs->ccr = (unsigned long)reg_val; 634 else if (reg_id == REG_ID("DAR")) 635 regs->dar = (unsigned long)reg_val; 636 else if (reg_id == REG_ID("DSISR")) 637 regs->dsisr = (unsigned long)reg_val; 638 } 639 640 static struct fadump_reg_entry* 641 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 642 { 643 memset(regs, 0, sizeof(struct pt_regs)); 644 645 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 646 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 647 be64_to_cpu(reg_entry->reg_value)); 648 reg_entry++; 649 } 650 reg_entry++; 651 return reg_entry; 652 } 653 654 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 655 { 656 struct elf_prstatus prstatus; 657 658 memset(&prstatus, 0, sizeof(prstatus)); 659 /* 660 * FIXME: How do i get PID? Do I really need it? 661 * prstatus.pr_pid = ???? 662 */ 663 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 664 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 665 &prstatus, sizeof(prstatus)); 666 return buf; 667 } 668 669 static void fadump_update_elfcore_header(char *bufp) 670 { 671 struct elfhdr *elf; 672 struct elf_phdr *phdr; 673 674 elf = (struct elfhdr *)bufp; 675 bufp += sizeof(struct elfhdr); 676 677 /* First note is a place holder for cpu notes info. */ 678 phdr = (struct elf_phdr *)bufp; 679 680 if (phdr->p_type == PT_NOTE) { 681 phdr->p_paddr = fw_dump.cpu_notes_buf; 682 phdr->p_offset = phdr->p_paddr; 683 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 684 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 685 } 686 return; 687 } 688 689 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 690 { 691 void *vaddr; 692 struct page *page; 693 unsigned long order, count, i; 694 695 order = get_order(size); 696 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 697 if (!vaddr) 698 return NULL; 699 700 count = 1 << order; 701 page = virt_to_page(vaddr); 702 for (i = 0; i < count; i++) 703 SetPageReserved(page + i); 704 return vaddr; 705 } 706 707 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 708 { 709 struct page *page; 710 unsigned long order, count, i; 711 712 order = get_order(size); 713 count = 1 << order; 714 page = virt_to_page(vaddr); 715 for (i = 0; i < count; i++) 716 ClearPageReserved(page + i); 717 __free_pages(page, order); 718 } 719 720 /* 721 * Read CPU state dump data and convert it into ELF notes. 722 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 723 * used to access the data to allow for additional fields to be added without 724 * affecting compatibility. Each list of registers for a CPU starts with 725 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 726 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 727 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 728 * of register value. For more details refer to PAPR document. 729 * 730 * Only for the crashing cpu we ignore the CPU dump data and get exact 731 * state from fadump crash info structure populated by first kernel at the 732 * time of crash. 733 */ 734 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 735 { 736 struct fadump_reg_save_area_header *reg_header; 737 struct fadump_reg_entry *reg_entry; 738 struct fadump_crash_info_header *fdh = NULL; 739 void *vaddr; 740 unsigned long addr; 741 u32 num_cpus, *note_buf; 742 struct pt_regs regs; 743 int i, rc = 0, cpu = 0; 744 745 if (!fdm->cpu_state_data.bytes_dumped) 746 return -EINVAL; 747 748 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 749 vaddr = __va(addr); 750 751 reg_header = vaddr; 752 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 753 printk(KERN_ERR "Unable to read register save area.\n"); 754 return -ENOENT; 755 } 756 pr_debug("--------CPU State Data------------\n"); 757 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 758 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 759 760 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 761 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 762 pr_debug("NumCpus : %u\n", num_cpus); 763 vaddr += sizeof(u32); 764 reg_entry = (struct fadump_reg_entry *)vaddr; 765 766 /* Allocate buffer to hold cpu crash notes. */ 767 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 768 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 769 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 770 if (!note_buf) { 771 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 772 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 773 return -ENOMEM; 774 } 775 fw_dump.cpu_notes_buf = __pa(note_buf); 776 777 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 778 (num_cpus * sizeof(note_buf_t)), note_buf); 779 780 if (fw_dump.fadumphdr_addr) 781 fdh = __va(fw_dump.fadumphdr_addr); 782 783 for (i = 0; i < num_cpus; i++) { 784 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 785 printk(KERN_ERR "Unable to read CPU state data\n"); 786 rc = -ENOENT; 787 goto error_out; 788 } 789 /* Lower 4 bytes of reg_value contains logical cpu id */ 790 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 791 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 792 SKIP_TO_NEXT_CPU(reg_entry); 793 continue; 794 } 795 pr_debug("Reading register data for cpu %d...\n", cpu); 796 if (fdh && fdh->crashing_cpu == cpu) { 797 regs = fdh->regs; 798 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 799 SKIP_TO_NEXT_CPU(reg_entry); 800 } else { 801 reg_entry++; 802 reg_entry = fadump_read_registers(reg_entry, ®s); 803 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 804 } 805 } 806 final_note(note_buf); 807 808 if (fdh) { 809 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 810 fdh->elfcorehdr_addr); 811 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 812 } 813 return 0; 814 815 error_out: 816 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 817 fw_dump.cpu_notes_buf_size); 818 fw_dump.cpu_notes_buf = 0; 819 fw_dump.cpu_notes_buf_size = 0; 820 return rc; 821 822 } 823 824 /* 825 * Validate and process the dump data stored by firmware before exporting 826 * it through '/proc/vmcore'. 827 */ 828 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 829 { 830 struct fadump_crash_info_header *fdh; 831 int rc = 0; 832 833 if (!fdm_active || !fw_dump.fadumphdr_addr) 834 return -EINVAL; 835 836 /* Check if the dump data is valid. */ 837 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 838 (fdm_active->cpu_state_data.error_flags != 0) || 839 (fdm_active->rmr_region.error_flags != 0)) { 840 printk(KERN_ERR "Dump taken by platform is not valid\n"); 841 return -EINVAL; 842 } 843 if ((fdm_active->rmr_region.bytes_dumped != 844 fdm_active->rmr_region.source_len) || 845 !fdm_active->cpu_state_data.bytes_dumped) { 846 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 847 return -EINVAL; 848 } 849 850 /* Validate the fadump crash info header */ 851 fdh = __va(fw_dump.fadumphdr_addr); 852 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 853 printk(KERN_ERR "Crash info header is not valid.\n"); 854 return -EINVAL; 855 } 856 857 rc = fadump_build_cpu_notes(fdm_active); 858 if (rc) 859 return rc; 860 861 /* 862 * We are done validating dump info and elfcore header is now ready 863 * to be exported. set elfcorehdr_addr so that vmcore module will 864 * export the elfcore header through '/proc/vmcore'. 865 */ 866 elfcorehdr_addr = fdh->elfcorehdr_addr; 867 868 return 0; 869 } 870 871 static inline void fadump_add_crash_memory(unsigned long long base, 872 unsigned long long end) 873 { 874 if (base == end) 875 return; 876 877 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 878 crash_mem_ranges, base, end - 1, (end - base)); 879 crash_memory_ranges[crash_mem_ranges].base = base; 880 crash_memory_ranges[crash_mem_ranges].size = end - base; 881 crash_mem_ranges++; 882 } 883 884 static void fadump_exclude_reserved_area(unsigned long long start, 885 unsigned long long end) 886 { 887 unsigned long long ra_start, ra_end; 888 889 ra_start = fw_dump.reserve_dump_area_start; 890 ra_end = ra_start + fw_dump.reserve_dump_area_size; 891 892 if ((ra_start < end) && (ra_end > start)) { 893 if ((start < ra_start) && (end > ra_end)) { 894 fadump_add_crash_memory(start, ra_start); 895 fadump_add_crash_memory(ra_end, end); 896 } else if (start < ra_start) { 897 fadump_add_crash_memory(start, ra_start); 898 } else if (ra_end < end) { 899 fadump_add_crash_memory(ra_end, end); 900 } 901 } else 902 fadump_add_crash_memory(start, end); 903 } 904 905 static int fadump_init_elfcore_header(char *bufp) 906 { 907 struct elfhdr *elf; 908 909 elf = (struct elfhdr *) bufp; 910 bufp += sizeof(struct elfhdr); 911 memcpy(elf->e_ident, ELFMAG, SELFMAG); 912 elf->e_ident[EI_CLASS] = ELF_CLASS; 913 elf->e_ident[EI_DATA] = ELF_DATA; 914 elf->e_ident[EI_VERSION] = EV_CURRENT; 915 elf->e_ident[EI_OSABI] = ELF_OSABI; 916 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 917 elf->e_type = ET_CORE; 918 elf->e_machine = ELF_ARCH; 919 elf->e_version = EV_CURRENT; 920 elf->e_entry = 0; 921 elf->e_phoff = sizeof(struct elfhdr); 922 elf->e_shoff = 0; 923 #if defined(_CALL_ELF) 924 elf->e_flags = _CALL_ELF; 925 #else 926 elf->e_flags = 0; 927 #endif 928 elf->e_ehsize = sizeof(struct elfhdr); 929 elf->e_phentsize = sizeof(struct elf_phdr); 930 elf->e_phnum = 0; 931 elf->e_shentsize = 0; 932 elf->e_shnum = 0; 933 elf->e_shstrndx = 0; 934 935 return 0; 936 } 937 938 /* 939 * Traverse through memblock structure and setup crash memory ranges. These 940 * ranges will be used create PT_LOAD program headers in elfcore header. 941 */ 942 static void fadump_setup_crash_memory_ranges(void) 943 { 944 struct memblock_region *reg; 945 unsigned long long start, end; 946 947 pr_debug("Setup crash memory ranges.\n"); 948 crash_mem_ranges = 0; 949 /* 950 * add the first memory chunk (RMA_START through boot_memory_size) as 951 * a separate memory chunk. The reason is, at the time crash firmware 952 * will move the content of this memory chunk to different location 953 * specified during fadump registration. We need to create a separate 954 * program header for this chunk with the correct offset. 955 */ 956 fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 957 958 for_each_memblock(memory, reg) { 959 start = (unsigned long long)reg->base; 960 end = start + (unsigned long long)reg->size; 961 962 /* 963 * skip the first memory chunk that is already added (RMA_START 964 * through boot_memory_size). This logic needs a relook if and 965 * when RMA_START changes to a non-zero value. 966 */ 967 BUILD_BUG_ON(RMA_START != 0); 968 if (start < fw_dump.boot_memory_size) { 969 if (end > fw_dump.boot_memory_size) 970 start = fw_dump.boot_memory_size; 971 else 972 continue; 973 } 974 975 /* add this range excluding the reserved dump area. */ 976 fadump_exclude_reserved_area(start, end); 977 } 978 } 979 980 /* 981 * If the given physical address falls within the boot memory region then 982 * return the relocated address that points to the dump region reserved 983 * for saving initial boot memory contents. 984 */ 985 static inline unsigned long fadump_relocate(unsigned long paddr) 986 { 987 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 988 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 989 else 990 return paddr; 991 } 992 993 static int fadump_create_elfcore_headers(char *bufp) 994 { 995 struct elfhdr *elf; 996 struct elf_phdr *phdr; 997 int i; 998 999 fadump_init_elfcore_header(bufp); 1000 elf = (struct elfhdr *)bufp; 1001 bufp += sizeof(struct elfhdr); 1002 1003 /* 1004 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1005 * will be populated during second kernel boot after crash. Hence 1006 * this PT_NOTE will always be the first elf note. 1007 * 1008 * NOTE: Any new ELF note addition should be placed after this note. 1009 */ 1010 phdr = (struct elf_phdr *)bufp; 1011 bufp += sizeof(struct elf_phdr); 1012 phdr->p_type = PT_NOTE; 1013 phdr->p_flags = 0; 1014 phdr->p_vaddr = 0; 1015 phdr->p_align = 0; 1016 1017 phdr->p_offset = 0; 1018 phdr->p_paddr = 0; 1019 phdr->p_filesz = 0; 1020 phdr->p_memsz = 0; 1021 1022 (elf->e_phnum)++; 1023 1024 /* setup ELF PT_NOTE for vmcoreinfo */ 1025 phdr = (struct elf_phdr *)bufp; 1026 bufp += sizeof(struct elf_phdr); 1027 phdr->p_type = PT_NOTE; 1028 phdr->p_flags = 0; 1029 phdr->p_vaddr = 0; 1030 phdr->p_align = 0; 1031 1032 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1033 phdr->p_offset = phdr->p_paddr; 1034 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1035 1036 /* Increment number of program headers. */ 1037 (elf->e_phnum)++; 1038 1039 /* setup PT_LOAD sections. */ 1040 1041 for (i = 0; i < crash_mem_ranges; i++) { 1042 unsigned long long mbase, msize; 1043 mbase = crash_memory_ranges[i].base; 1044 msize = crash_memory_ranges[i].size; 1045 1046 if (!msize) 1047 continue; 1048 1049 phdr = (struct elf_phdr *)bufp; 1050 bufp += sizeof(struct elf_phdr); 1051 phdr->p_type = PT_LOAD; 1052 phdr->p_flags = PF_R|PF_W|PF_X; 1053 phdr->p_offset = mbase; 1054 1055 if (mbase == RMA_START) { 1056 /* 1057 * The entire RMA region will be moved by firmware 1058 * to the specified destination_address. Hence set 1059 * the correct offset. 1060 */ 1061 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1062 } 1063 1064 phdr->p_paddr = mbase; 1065 phdr->p_vaddr = (unsigned long)__va(mbase); 1066 phdr->p_filesz = msize; 1067 phdr->p_memsz = msize; 1068 phdr->p_align = 0; 1069 1070 /* Increment number of program headers. */ 1071 (elf->e_phnum)++; 1072 } 1073 return 0; 1074 } 1075 1076 static unsigned long init_fadump_header(unsigned long addr) 1077 { 1078 struct fadump_crash_info_header *fdh; 1079 1080 if (!addr) 1081 return 0; 1082 1083 fw_dump.fadumphdr_addr = addr; 1084 fdh = __va(addr); 1085 addr += sizeof(struct fadump_crash_info_header); 1086 1087 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1088 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1089 fdh->elfcorehdr_addr = addr; 1090 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1091 fdh->crashing_cpu = CPU_UNKNOWN; 1092 1093 return addr; 1094 } 1095 1096 static int register_fadump(void) 1097 { 1098 unsigned long addr; 1099 void *vaddr; 1100 1101 /* 1102 * If no memory is reserved then we can not register for firmware- 1103 * assisted dump. 1104 */ 1105 if (!fw_dump.reserve_dump_area_size) 1106 return -ENODEV; 1107 1108 fadump_setup_crash_memory_ranges(); 1109 1110 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1111 /* Initialize fadump crash info header. */ 1112 addr = init_fadump_header(addr); 1113 vaddr = __va(addr); 1114 1115 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1116 fadump_create_elfcore_headers(vaddr); 1117 1118 /* register the future kernel dump with firmware. */ 1119 return register_fw_dump(&fdm); 1120 } 1121 1122 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1123 { 1124 int rc = 0; 1125 unsigned int wait_time; 1126 1127 pr_debug("Un-register firmware-assisted dump\n"); 1128 1129 /* TODO: Add upper time limit for the delay */ 1130 do { 1131 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1132 FADUMP_UNREGISTER, fdm, 1133 sizeof(struct fadump_mem_struct)); 1134 1135 wait_time = rtas_busy_delay_time(rc); 1136 if (wait_time) 1137 mdelay(wait_time); 1138 } while (wait_time); 1139 1140 if (rc) { 1141 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1142 " unexpected error(%d).\n", rc); 1143 return rc; 1144 } 1145 fw_dump.dump_registered = 0; 1146 return 0; 1147 } 1148 1149 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1150 { 1151 int rc = 0; 1152 unsigned int wait_time; 1153 1154 pr_debug("Invalidating firmware-assisted dump registration\n"); 1155 1156 /* TODO: Add upper time limit for the delay */ 1157 do { 1158 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1159 FADUMP_INVALIDATE, fdm, 1160 sizeof(struct fadump_mem_struct)); 1161 1162 wait_time = rtas_busy_delay_time(rc); 1163 if (wait_time) 1164 mdelay(wait_time); 1165 } while (wait_time); 1166 1167 if (rc) { 1168 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1169 return rc; 1170 } 1171 fw_dump.dump_active = 0; 1172 fdm_active = NULL; 1173 return 0; 1174 } 1175 1176 void fadump_cleanup(void) 1177 { 1178 /* Invalidate the registration only if dump is active. */ 1179 if (fw_dump.dump_active) { 1180 init_fadump_mem_struct(&fdm, 1181 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1182 fadump_invalidate_dump(&fdm); 1183 } else if (fw_dump.dump_registered) { 1184 /* Un-register Firmware-assisted dump if it was registered. */ 1185 fadump_unregister_dump(&fdm); 1186 } 1187 } 1188 1189 static void fadump_free_reserved_memory(unsigned long start_pfn, 1190 unsigned long end_pfn) 1191 { 1192 unsigned long pfn; 1193 unsigned long time_limit = jiffies + HZ; 1194 1195 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1196 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1197 1198 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1199 free_reserved_page(pfn_to_page(pfn)); 1200 1201 if (time_after(jiffies, time_limit)) { 1202 cond_resched(); 1203 time_limit = jiffies + HZ; 1204 } 1205 } 1206 } 1207 1208 /* 1209 * Skip memory holes and free memory that was actually reserved. 1210 */ 1211 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1212 { 1213 struct memblock_region *reg; 1214 unsigned long tstart, tend; 1215 unsigned long start_pfn = PHYS_PFN(start); 1216 unsigned long end_pfn = PHYS_PFN(end); 1217 1218 for_each_memblock(memory, reg) { 1219 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1220 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1221 if (tstart < tend) { 1222 fadump_free_reserved_memory(tstart, tend); 1223 1224 if (tend == end_pfn) 1225 break; 1226 1227 start_pfn = tend + 1; 1228 } 1229 } 1230 } 1231 1232 /* 1233 * Release the memory that was reserved in early boot to preserve the memory 1234 * contents. The released memory will be available for general use. 1235 */ 1236 static void fadump_release_memory(unsigned long begin, unsigned long end) 1237 { 1238 unsigned long ra_start, ra_end; 1239 1240 ra_start = fw_dump.reserve_dump_area_start; 1241 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1242 1243 /* 1244 * exclude the dump reserve area. Will reuse it for next 1245 * fadump registration. 1246 */ 1247 if (begin < ra_end && end > ra_start) { 1248 if (begin < ra_start) 1249 fadump_release_reserved_area(begin, ra_start); 1250 if (end > ra_end) 1251 fadump_release_reserved_area(ra_end, end); 1252 } else 1253 fadump_release_reserved_area(begin, end); 1254 } 1255 1256 static void fadump_invalidate_release_mem(void) 1257 { 1258 unsigned long reserved_area_start, reserved_area_end; 1259 unsigned long destination_address; 1260 1261 mutex_lock(&fadump_mutex); 1262 if (!fw_dump.dump_active) { 1263 mutex_unlock(&fadump_mutex); 1264 return; 1265 } 1266 1267 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1268 fadump_cleanup(); 1269 mutex_unlock(&fadump_mutex); 1270 1271 /* 1272 * Save the current reserved memory bounds we will require them 1273 * later for releasing the memory for general use. 1274 */ 1275 reserved_area_start = fw_dump.reserve_dump_area_start; 1276 reserved_area_end = reserved_area_start + 1277 fw_dump.reserve_dump_area_size; 1278 /* 1279 * Setup reserve_dump_area_start and its size so that we can 1280 * reuse this reserved memory for Re-registration. 1281 */ 1282 fw_dump.reserve_dump_area_start = destination_address; 1283 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1284 1285 fadump_release_memory(reserved_area_start, reserved_area_end); 1286 if (fw_dump.cpu_notes_buf) { 1287 fadump_cpu_notes_buf_free( 1288 (unsigned long)__va(fw_dump.cpu_notes_buf), 1289 fw_dump.cpu_notes_buf_size); 1290 fw_dump.cpu_notes_buf = 0; 1291 fw_dump.cpu_notes_buf_size = 0; 1292 } 1293 /* Initialize the kernel dump memory structure for FAD registration. */ 1294 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1295 } 1296 1297 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1298 struct kobj_attribute *attr, 1299 const char *buf, size_t count) 1300 { 1301 int input = -1; 1302 1303 if (!fw_dump.dump_active) 1304 return -EPERM; 1305 1306 if (kstrtoint(buf, 0, &input)) 1307 return -EINVAL; 1308 1309 if (input == 1) { 1310 /* 1311 * Take away the '/proc/vmcore'. We are releasing the dump 1312 * memory, hence it will not be valid anymore. 1313 */ 1314 #ifdef CONFIG_PROC_VMCORE 1315 vmcore_cleanup(); 1316 #endif 1317 fadump_invalidate_release_mem(); 1318 1319 } else 1320 return -EINVAL; 1321 return count; 1322 } 1323 1324 static ssize_t fadump_enabled_show(struct kobject *kobj, 1325 struct kobj_attribute *attr, 1326 char *buf) 1327 { 1328 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1329 } 1330 1331 static ssize_t fadump_register_show(struct kobject *kobj, 1332 struct kobj_attribute *attr, 1333 char *buf) 1334 { 1335 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1336 } 1337 1338 static ssize_t fadump_register_store(struct kobject *kobj, 1339 struct kobj_attribute *attr, 1340 const char *buf, size_t count) 1341 { 1342 int ret = 0; 1343 int input = -1; 1344 1345 if (!fw_dump.fadump_enabled || fdm_active) 1346 return -EPERM; 1347 1348 if (kstrtoint(buf, 0, &input)) 1349 return -EINVAL; 1350 1351 mutex_lock(&fadump_mutex); 1352 1353 switch (input) { 1354 case 0: 1355 if (fw_dump.dump_registered == 0) { 1356 goto unlock_out; 1357 } 1358 /* Un-register Firmware-assisted dump */ 1359 fadump_unregister_dump(&fdm); 1360 break; 1361 case 1: 1362 if (fw_dump.dump_registered == 1) { 1363 ret = -EEXIST; 1364 goto unlock_out; 1365 } 1366 /* Register Firmware-assisted dump */ 1367 ret = register_fadump(); 1368 break; 1369 default: 1370 ret = -EINVAL; 1371 break; 1372 } 1373 1374 unlock_out: 1375 mutex_unlock(&fadump_mutex); 1376 return ret < 0 ? ret : count; 1377 } 1378 1379 static int fadump_region_show(struct seq_file *m, void *private) 1380 { 1381 const struct fadump_mem_struct *fdm_ptr; 1382 1383 if (!fw_dump.fadump_enabled) 1384 return 0; 1385 1386 mutex_lock(&fadump_mutex); 1387 if (fdm_active) 1388 fdm_ptr = fdm_active; 1389 else { 1390 mutex_unlock(&fadump_mutex); 1391 fdm_ptr = &fdm; 1392 } 1393 1394 seq_printf(m, 1395 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1396 "Dumped: %#llx\n", 1397 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1398 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1399 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1400 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1401 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1402 seq_printf(m, 1403 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1404 "Dumped: %#llx\n", 1405 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1406 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1407 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1408 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1409 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1410 seq_printf(m, 1411 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1412 "Dumped: %#llx\n", 1413 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1414 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1415 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1416 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1417 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1418 1419 if (!fdm_active || 1420 (fw_dump.reserve_dump_area_start == 1421 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1422 goto out; 1423 1424 /* Dump is active. Show reserved memory region. */ 1425 seq_printf(m, 1426 " : [%#016llx-%#016llx] %#llx bytes, " 1427 "Dumped: %#llx\n", 1428 (unsigned long long)fw_dump.reserve_dump_area_start, 1429 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1430 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1431 fw_dump.reserve_dump_area_start, 1432 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1433 fw_dump.reserve_dump_area_start); 1434 out: 1435 if (fdm_active) 1436 mutex_unlock(&fadump_mutex); 1437 return 0; 1438 } 1439 1440 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1441 0200, NULL, 1442 fadump_release_memory_store); 1443 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1444 0444, fadump_enabled_show, 1445 NULL); 1446 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1447 0644, fadump_register_show, 1448 fadump_register_store); 1449 1450 static int fadump_region_open(struct inode *inode, struct file *file) 1451 { 1452 return single_open(file, fadump_region_show, inode->i_private); 1453 } 1454 1455 static const struct file_operations fadump_region_fops = { 1456 .open = fadump_region_open, 1457 .read = seq_read, 1458 .llseek = seq_lseek, 1459 .release = single_release, 1460 }; 1461 1462 static void fadump_init_files(void) 1463 { 1464 struct dentry *debugfs_file; 1465 int rc = 0; 1466 1467 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1468 if (rc) 1469 printk(KERN_ERR "fadump: unable to create sysfs file" 1470 " fadump_enabled (%d)\n", rc); 1471 1472 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1473 if (rc) 1474 printk(KERN_ERR "fadump: unable to create sysfs file" 1475 " fadump_registered (%d)\n", rc); 1476 1477 debugfs_file = debugfs_create_file("fadump_region", 0444, 1478 powerpc_debugfs_root, NULL, 1479 &fadump_region_fops); 1480 if (!debugfs_file) 1481 printk(KERN_ERR "fadump: unable to create debugfs file" 1482 " fadump_region\n"); 1483 1484 if (fw_dump.dump_active) { 1485 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1486 if (rc) 1487 printk(KERN_ERR "fadump: unable to create sysfs file" 1488 " fadump_release_mem (%d)\n", rc); 1489 } 1490 return; 1491 } 1492 1493 /* 1494 * Prepare for firmware-assisted dump. 1495 */ 1496 int __init setup_fadump(void) 1497 { 1498 if (!fw_dump.fadump_enabled) 1499 return 0; 1500 1501 if (!fw_dump.fadump_supported) { 1502 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1503 " this hardware\n"); 1504 return 0; 1505 } 1506 1507 fadump_show_config(); 1508 /* 1509 * If dump data is available then see if it is valid and prepare for 1510 * saving it to the disk. 1511 */ 1512 if (fw_dump.dump_active) { 1513 /* 1514 * if dump process fails then invalidate the registration 1515 * and release memory before proceeding for re-registration. 1516 */ 1517 if (process_fadump(fdm_active) < 0) 1518 fadump_invalidate_release_mem(); 1519 } 1520 /* Initialize the kernel dump memory structure for FAD registration. */ 1521 else if (fw_dump.reserve_dump_area_size) 1522 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1523 fadump_init_files(); 1524 1525 return 1; 1526 } 1527 subsys_initcall(setup_fadump); 1528