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 #include <linux/slab.h> 38 39 #include <asm/debugfs.h> 40 #include <asm/page.h> 41 #include <asm/prom.h> 42 #include <asm/rtas.h> 43 #include <asm/fadump.h> 44 #include <asm/setup.h> 45 46 static struct fw_dump fw_dump; 47 static struct fadump_mem_struct fdm; 48 static const struct fadump_mem_struct *fdm_active; 49 50 static DEFINE_MUTEX(fadump_mutex); 51 struct fad_crash_memory_ranges *crash_memory_ranges; 52 int crash_memory_ranges_size; 53 int crash_mem_ranges; 54 int max_crash_mem_ranges; 55 56 /* Scan the Firmware Assisted dump configuration details. */ 57 int __init early_init_dt_scan_fw_dump(unsigned long node, 58 const char *uname, int depth, void *data) 59 { 60 const __be32 *sections; 61 int i, num_sections; 62 int size; 63 const __be32 *token; 64 65 if (depth != 1 || strcmp(uname, "rtas") != 0) 66 return 0; 67 68 /* 69 * Check if Firmware Assisted dump is supported. if yes, check 70 * if dump has been initiated on last reboot. 71 */ 72 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); 73 if (!token) 74 return 1; 75 76 fw_dump.fadump_supported = 1; 77 fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token); 78 79 /* 80 * The 'ibm,kernel-dump' rtas node is present only if there is 81 * dump data waiting for us. 82 */ 83 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); 84 if (fdm_active) 85 fw_dump.dump_active = 1; 86 87 /* Get the sizes required to store dump data for the firmware provided 88 * dump sections. 89 * For each dump section type supported, a 32bit cell which defines 90 * the ID of a supported section followed by two 32 bit cells which 91 * gives teh size of the section in bytes. 92 */ 93 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", 94 &size); 95 96 if (!sections) 97 return 1; 98 99 num_sections = size / (3 * sizeof(u32)); 100 101 for (i = 0; i < num_sections; i++, sections += 3) { 102 u32 type = (u32)of_read_number(sections, 1); 103 104 switch (type) { 105 case FADUMP_CPU_STATE_DATA: 106 fw_dump.cpu_state_data_size = 107 of_read_ulong(§ions[1], 2); 108 break; 109 case FADUMP_HPTE_REGION: 110 fw_dump.hpte_region_size = 111 of_read_ulong(§ions[1], 2); 112 break; 113 } 114 } 115 116 return 1; 117 } 118 119 /* 120 * If fadump is registered, check if the memory provided 121 * falls within boot memory area. 122 */ 123 int is_fadump_boot_memory_area(u64 addr, ulong size) 124 { 125 if (!fw_dump.dump_registered) 126 return 0; 127 128 return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size; 129 } 130 131 int should_fadump_crash(void) 132 { 133 if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) 134 return 0; 135 return 1; 136 } 137 138 int is_fadump_active(void) 139 { 140 return fw_dump.dump_active; 141 } 142 143 /* 144 * Returns 1, if there are no holes in boot memory area, 145 * 0 otherwise. 146 */ 147 static int is_boot_memory_area_contiguous(void) 148 { 149 struct memblock_region *reg; 150 unsigned long tstart, tend; 151 unsigned long start_pfn = PHYS_PFN(RMA_START); 152 unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size); 153 unsigned int ret = 0; 154 155 for_each_memblock(memory, reg) { 156 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 157 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 158 if (tstart < tend) { 159 /* Memory hole from start_pfn to tstart */ 160 if (tstart > start_pfn) 161 break; 162 163 if (tend == end_pfn) { 164 ret = 1; 165 break; 166 } 167 168 start_pfn = tend + 1; 169 } 170 } 171 172 return ret; 173 } 174 175 /* Print firmware assisted dump configurations for debugging purpose. */ 176 static void fadump_show_config(void) 177 { 178 pr_debug("Support for firmware-assisted dump (fadump): %s\n", 179 (fw_dump.fadump_supported ? "present" : "no support")); 180 181 if (!fw_dump.fadump_supported) 182 return; 183 184 pr_debug("Fadump enabled : %s\n", 185 (fw_dump.fadump_enabled ? "yes" : "no")); 186 pr_debug("Dump Active : %s\n", 187 (fw_dump.dump_active ? "yes" : "no")); 188 pr_debug("Dump section sizes:\n"); 189 pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); 190 pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); 191 pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); 192 } 193 194 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, 195 unsigned long addr) 196 { 197 if (!fdm) 198 return 0; 199 200 memset(fdm, 0, sizeof(struct fadump_mem_struct)); 201 addr = addr & PAGE_MASK; 202 203 fdm->header.dump_format_version = cpu_to_be32(0x00000001); 204 fdm->header.dump_num_sections = cpu_to_be16(3); 205 fdm->header.dump_status_flag = 0; 206 fdm->header.offset_first_dump_section = 207 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data)); 208 209 /* 210 * Fields for disk dump option. 211 * We are not using disk dump option, hence set these fields to 0. 212 */ 213 fdm->header.dd_block_size = 0; 214 fdm->header.dd_block_offset = 0; 215 fdm->header.dd_num_blocks = 0; 216 fdm->header.dd_offset_disk_path = 0; 217 218 /* set 0 to disable an automatic dump-reboot. */ 219 fdm->header.max_time_auto = 0; 220 221 /* Kernel dump sections */ 222 /* cpu state data section. */ 223 fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 224 fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA); 225 fdm->cpu_state_data.source_address = 0; 226 fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size); 227 fdm->cpu_state_data.destination_address = cpu_to_be64(addr); 228 addr += fw_dump.cpu_state_data_size; 229 230 /* hpte region section */ 231 fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 232 fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION); 233 fdm->hpte_region.source_address = 0; 234 fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size); 235 fdm->hpte_region.destination_address = cpu_to_be64(addr); 236 addr += fw_dump.hpte_region_size; 237 238 /* RMA region section */ 239 fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG); 240 fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION); 241 fdm->rmr_region.source_address = cpu_to_be64(RMA_START); 242 fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size); 243 fdm->rmr_region.destination_address = cpu_to_be64(addr); 244 addr += fw_dump.boot_memory_size; 245 246 return addr; 247 } 248 249 /** 250 * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM 251 * 252 * Function to find the largest memory size we need to reserve during early 253 * boot process. This will be the size of the memory that is required for a 254 * kernel to boot successfully. 255 * 256 * This function has been taken from phyp-assisted dump feature implementation. 257 * 258 * returns larger of 256MB or 5% rounded down to multiples of 256MB. 259 * 260 * TODO: Come up with better approach to find out more accurate memory size 261 * that is required for a kernel to boot successfully. 262 * 263 */ 264 static inline unsigned long fadump_calculate_reserve_size(void) 265 { 266 int ret; 267 unsigned long long base, size; 268 269 if (fw_dump.reserve_bootvar) 270 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); 271 272 /* 273 * Check if the size is specified through crashkernel= cmdline 274 * option. If yes, then use that but ignore base as fadump reserves 275 * memory at a predefined offset. 276 */ 277 ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), 278 &size, &base); 279 if (ret == 0 && size > 0) { 280 unsigned long max_size; 281 282 if (fw_dump.reserve_bootvar) 283 pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); 284 285 fw_dump.reserve_bootvar = (unsigned long)size; 286 287 /* 288 * Adjust if the boot memory size specified is above 289 * the upper limit. 290 */ 291 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; 292 if (fw_dump.reserve_bootvar > max_size) { 293 fw_dump.reserve_bootvar = max_size; 294 pr_info("Adjusted boot memory size to %luMB\n", 295 (fw_dump.reserve_bootvar >> 20)); 296 } 297 298 return fw_dump.reserve_bootvar; 299 } else if (fw_dump.reserve_bootvar) { 300 /* 301 * 'fadump_reserve_mem=' is being used to reserve memory 302 * for firmware-assisted dump. 303 */ 304 return fw_dump.reserve_bootvar; 305 } 306 307 /* divide by 20 to get 5% of value */ 308 size = memblock_phys_mem_size() / 20; 309 310 /* round it down in multiples of 256 */ 311 size = size & ~0x0FFFFFFFUL; 312 313 /* Truncate to memory_limit. We don't want to over reserve the memory.*/ 314 if (memory_limit && size > memory_limit) 315 size = memory_limit; 316 317 return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); 318 } 319 320 /* 321 * Calculate the total memory size required to be reserved for 322 * firmware-assisted dump registration. 323 */ 324 static unsigned long get_fadump_area_size(void) 325 { 326 unsigned long size = 0; 327 328 size += fw_dump.cpu_state_data_size; 329 size += fw_dump.hpte_region_size; 330 size += fw_dump.boot_memory_size; 331 size += sizeof(struct fadump_crash_info_header); 332 size += sizeof(struct elfhdr); /* ELF core header.*/ 333 size += sizeof(struct elf_phdr); /* place holder for cpu notes */ 334 /* Program headers for crash memory regions. */ 335 size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); 336 337 size = PAGE_ALIGN(size); 338 return size; 339 } 340 341 static void __init fadump_reserve_crash_area(unsigned long base, 342 unsigned long size) 343 { 344 struct memblock_region *reg; 345 unsigned long mstart, mend, msize; 346 347 for_each_memblock(memory, reg) { 348 mstart = max_t(unsigned long, base, reg->base); 349 mend = reg->base + reg->size; 350 mend = min(base + size, mend); 351 352 if (mstart < mend) { 353 msize = mend - mstart; 354 memblock_reserve(mstart, msize); 355 pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n", 356 (msize >> 20), mstart); 357 } 358 } 359 } 360 361 int __init fadump_reserve_mem(void) 362 { 363 unsigned long base, size, memory_boundary; 364 365 if (!fw_dump.fadump_enabled) 366 return 0; 367 368 if (!fw_dump.fadump_supported) { 369 printk(KERN_INFO "Firmware-assisted dump is not supported on" 370 " this hardware\n"); 371 fw_dump.fadump_enabled = 0; 372 return 0; 373 } 374 /* 375 * Initialize boot memory size 376 * If dump is active then we have already calculated the size during 377 * first kernel. 378 */ 379 if (fdm_active) 380 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len); 381 else 382 fw_dump.boot_memory_size = fadump_calculate_reserve_size(); 383 384 /* 385 * Calculate the memory boundary. 386 * If memory_limit is less than actual memory boundary then reserve 387 * the memory for fadump beyond the memory_limit and adjust the 388 * memory_limit accordingly, so that the running kernel can run with 389 * specified memory_limit. 390 */ 391 if (memory_limit && memory_limit < memblock_end_of_DRAM()) { 392 size = get_fadump_area_size(); 393 if ((memory_limit + size) < memblock_end_of_DRAM()) 394 memory_limit += size; 395 else 396 memory_limit = memblock_end_of_DRAM(); 397 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" 398 " dump, now %#016llx\n", memory_limit); 399 } 400 if (memory_limit) 401 memory_boundary = memory_limit; 402 else 403 memory_boundary = memblock_end_of_DRAM(); 404 405 if (fw_dump.dump_active) { 406 pr_info("Firmware-assisted dump is active.\n"); 407 408 #ifdef CONFIG_HUGETLB_PAGE 409 /* 410 * FADump capture kernel doesn't care much about hugepages. 411 * In fact, handling hugepages in capture kernel is asking for 412 * trouble. So, disable HugeTLB support when fadump is active. 413 */ 414 hugetlb_disabled = true; 415 #endif 416 /* 417 * If last boot has crashed then reserve all the memory 418 * above boot_memory_size so that we don't touch it until 419 * dump is written to disk by userspace tool. This memory 420 * will be released for general use once the dump is saved. 421 */ 422 base = fw_dump.boot_memory_size; 423 size = memory_boundary - base; 424 fadump_reserve_crash_area(base, size); 425 426 fw_dump.fadumphdr_addr = 427 be64_to_cpu(fdm_active->rmr_region.destination_address) + 428 be64_to_cpu(fdm_active->rmr_region.source_len); 429 pr_debug("fadumphdr_addr = %p\n", 430 (void *) fw_dump.fadumphdr_addr); 431 } else { 432 size = get_fadump_area_size(); 433 434 /* 435 * Reserve memory at an offset closer to bottom of the RAM to 436 * minimize the impact of memory hot-remove operation. We can't 437 * use memblock_find_in_range() here since it doesn't allocate 438 * from bottom to top. 439 */ 440 for (base = fw_dump.boot_memory_size; 441 base <= (memory_boundary - size); 442 base += size) { 443 if (memblock_is_region_memory(base, size) && 444 !memblock_is_region_reserved(base, size)) 445 break; 446 } 447 if ((base > (memory_boundary - size)) || 448 memblock_reserve(base, size)) { 449 pr_err("Failed to reserve memory\n"); 450 return 0; 451 } 452 453 pr_info("Reserved %ldMB of memory at %ldMB for firmware-" 454 "assisted dump (System RAM: %ldMB)\n", 455 (unsigned long)(size >> 20), 456 (unsigned long)(base >> 20), 457 (unsigned long)(memblock_phys_mem_size() >> 20)); 458 } 459 460 fw_dump.reserve_dump_area_start = base; 461 fw_dump.reserve_dump_area_size = size; 462 return 1; 463 } 464 465 unsigned long __init arch_reserved_kernel_pages(void) 466 { 467 return memblock_reserved_size() / PAGE_SIZE; 468 } 469 470 /* Look for fadump= cmdline option. */ 471 static int __init early_fadump_param(char *p) 472 { 473 if (!p) 474 return 1; 475 476 if (strncmp(p, "on", 2) == 0) 477 fw_dump.fadump_enabled = 1; 478 else if (strncmp(p, "off", 3) == 0) 479 fw_dump.fadump_enabled = 0; 480 481 return 0; 482 } 483 early_param("fadump", early_fadump_param); 484 485 /* 486 * Look for fadump_reserve_mem= cmdline option 487 * TODO: Remove references to 'fadump_reserve_mem=' parameter, 488 * the sooner 'crashkernel=' parameter is accustomed to. 489 */ 490 static int __init early_fadump_reserve_mem(char *p) 491 { 492 if (p) 493 fw_dump.reserve_bootvar = memparse(p, &p); 494 return 0; 495 } 496 early_param("fadump_reserve_mem", early_fadump_reserve_mem); 497 498 static int register_fw_dump(struct fadump_mem_struct *fdm) 499 { 500 int rc, err; 501 unsigned int wait_time; 502 503 pr_debug("Registering for firmware-assisted kernel dump...\n"); 504 505 /* TODO: Add upper time limit for the delay */ 506 do { 507 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 508 FADUMP_REGISTER, fdm, 509 sizeof(struct fadump_mem_struct)); 510 511 wait_time = rtas_busy_delay_time(rc); 512 if (wait_time) 513 mdelay(wait_time); 514 515 } while (wait_time); 516 517 err = -EIO; 518 switch (rc) { 519 default: 520 pr_err("Failed to register. Unknown Error(%d).\n", rc); 521 break; 522 case -1: 523 printk(KERN_ERR "Failed to register firmware-assisted kernel" 524 " dump. Hardware Error(%d).\n", rc); 525 break; 526 case -3: 527 if (!is_boot_memory_area_contiguous()) 528 pr_err("Can't have holes in boot memory area while " 529 "registering fadump\n"); 530 531 printk(KERN_ERR "Failed to register firmware-assisted kernel" 532 " dump. Parameter Error(%d).\n", rc); 533 err = -EINVAL; 534 break; 535 case -9: 536 printk(KERN_ERR "firmware-assisted kernel dump is already " 537 " registered."); 538 fw_dump.dump_registered = 1; 539 err = -EEXIST; 540 break; 541 case 0: 542 printk(KERN_INFO "firmware-assisted kernel dump registration" 543 " is successful\n"); 544 fw_dump.dump_registered = 1; 545 err = 0; 546 break; 547 } 548 return err; 549 } 550 551 void crash_fadump(struct pt_regs *regs, const char *str) 552 { 553 struct fadump_crash_info_header *fdh = NULL; 554 int old_cpu, this_cpu; 555 556 if (!should_fadump_crash()) 557 return; 558 559 /* 560 * old_cpu == -1 means this is the first CPU which has come here, 561 * go ahead and trigger fadump. 562 * 563 * old_cpu != -1 means some other CPU has already on it's way 564 * to trigger fadump, just keep looping here. 565 */ 566 this_cpu = smp_processor_id(); 567 old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); 568 569 if (old_cpu != -1) { 570 /* 571 * We can't loop here indefinitely. Wait as long as fadump 572 * is in force. If we race with fadump un-registration this 573 * loop will break and then we go down to normal panic path 574 * and reboot. If fadump is in force the first crashing 575 * cpu will definitely trigger fadump. 576 */ 577 while (fw_dump.dump_registered) 578 cpu_relax(); 579 return; 580 } 581 582 fdh = __va(fw_dump.fadumphdr_addr); 583 fdh->crashing_cpu = crashing_cpu; 584 crash_save_vmcoreinfo(); 585 586 if (regs) 587 fdh->regs = *regs; 588 else 589 ppc_save_regs(&fdh->regs); 590 591 fdh->online_mask = *cpu_online_mask; 592 593 /* Call ibm,os-term rtas call to trigger firmware assisted dump */ 594 rtas_os_term((char *)str); 595 } 596 597 #define GPR_MASK 0xffffff0000000000 598 static inline int fadump_gpr_index(u64 id) 599 { 600 int i = -1; 601 char str[3]; 602 603 if ((id & GPR_MASK) == REG_ID("GPR")) { 604 /* get the digits at the end */ 605 id &= ~GPR_MASK; 606 id >>= 24; 607 str[2] = '\0'; 608 str[1] = id & 0xff; 609 str[0] = (id >> 8) & 0xff; 610 sscanf(str, "%d", &i); 611 if (i > 31) 612 i = -1; 613 } 614 return i; 615 } 616 617 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, 618 u64 reg_val) 619 { 620 int i; 621 622 i = fadump_gpr_index(reg_id); 623 if (i >= 0) 624 regs->gpr[i] = (unsigned long)reg_val; 625 else if (reg_id == REG_ID("NIA")) 626 regs->nip = (unsigned long)reg_val; 627 else if (reg_id == REG_ID("MSR")) 628 regs->msr = (unsigned long)reg_val; 629 else if (reg_id == REG_ID("CTR")) 630 regs->ctr = (unsigned long)reg_val; 631 else if (reg_id == REG_ID("LR")) 632 regs->link = (unsigned long)reg_val; 633 else if (reg_id == REG_ID("XER")) 634 regs->xer = (unsigned long)reg_val; 635 else if (reg_id == REG_ID("CR")) 636 regs->ccr = (unsigned long)reg_val; 637 else if (reg_id == REG_ID("DAR")) 638 regs->dar = (unsigned long)reg_val; 639 else if (reg_id == REG_ID("DSISR")) 640 regs->dsisr = (unsigned long)reg_val; 641 } 642 643 static struct fadump_reg_entry* 644 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) 645 { 646 memset(regs, 0, sizeof(struct pt_regs)); 647 648 while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) { 649 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), 650 be64_to_cpu(reg_entry->reg_value)); 651 reg_entry++; 652 } 653 reg_entry++; 654 return reg_entry; 655 } 656 657 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) 658 { 659 struct elf_prstatus prstatus; 660 661 memset(&prstatus, 0, sizeof(prstatus)); 662 /* 663 * FIXME: How do i get PID? Do I really need it? 664 * prstatus.pr_pid = ???? 665 */ 666 elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); 667 buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, 668 &prstatus, sizeof(prstatus)); 669 return buf; 670 } 671 672 static void fadump_update_elfcore_header(char *bufp) 673 { 674 struct elfhdr *elf; 675 struct elf_phdr *phdr; 676 677 elf = (struct elfhdr *)bufp; 678 bufp += sizeof(struct elfhdr); 679 680 /* First note is a place holder for cpu notes info. */ 681 phdr = (struct elf_phdr *)bufp; 682 683 if (phdr->p_type == PT_NOTE) { 684 phdr->p_paddr = fw_dump.cpu_notes_buf; 685 phdr->p_offset = phdr->p_paddr; 686 phdr->p_filesz = fw_dump.cpu_notes_buf_size; 687 phdr->p_memsz = fw_dump.cpu_notes_buf_size; 688 } 689 return; 690 } 691 692 static void *fadump_cpu_notes_buf_alloc(unsigned long size) 693 { 694 void *vaddr; 695 struct page *page; 696 unsigned long order, count, i; 697 698 order = get_order(size); 699 vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); 700 if (!vaddr) 701 return NULL; 702 703 count = 1 << order; 704 page = virt_to_page(vaddr); 705 for (i = 0; i < count; i++) 706 SetPageReserved(page + i); 707 return vaddr; 708 } 709 710 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) 711 { 712 struct page *page; 713 unsigned long order, count, i; 714 715 order = get_order(size); 716 count = 1 << order; 717 page = virt_to_page(vaddr); 718 for (i = 0; i < count; i++) 719 ClearPageReserved(page + i); 720 __free_pages(page, order); 721 } 722 723 /* 724 * Read CPU state dump data and convert it into ELF notes. 725 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be 726 * used to access the data to allow for additional fields to be added without 727 * affecting compatibility. Each list of registers for a CPU starts with 728 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, 729 * 8 Byte ASCII identifier and 8 Byte register value. The register entry 730 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part 731 * of register value. For more details refer to PAPR document. 732 * 733 * Only for the crashing cpu we ignore the CPU dump data and get exact 734 * state from fadump crash info structure populated by first kernel at the 735 * time of crash. 736 */ 737 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) 738 { 739 struct fadump_reg_save_area_header *reg_header; 740 struct fadump_reg_entry *reg_entry; 741 struct fadump_crash_info_header *fdh = NULL; 742 void *vaddr; 743 unsigned long addr; 744 u32 num_cpus, *note_buf; 745 struct pt_regs regs; 746 int i, rc = 0, cpu = 0; 747 748 if (!fdm->cpu_state_data.bytes_dumped) 749 return -EINVAL; 750 751 addr = be64_to_cpu(fdm->cpu_state_data.destination_address); 752 vaddr = __va(addr); 753 754 reg_header = vaddr; 755 if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) { 756 printk(KERN_ERR "Unable to read register save area.\n"); 757 return -ENOENT; 758 } 759 pr_debug("--------CPU State Data------------\n"); 760 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); 761 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); 762 763 vaddr += be32_to_cpu(reg_header->num_cpu_offset); 764 num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); 765 pr_debug("NumCpus : %u\n", num_cpus); 766 vaddr += sizeof(u32); 767 reg_entry = (struct fadump_reg_entry *)vaddr; 768 769 /* Allocate buffer to hold cpu crash notes. */ 770 fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); 771 fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); 772 note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); 773 if (!note_buf) { 774 printk(KERN_ERR "Failed to allocate 0x%lx bytes for " 775 "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); 776 return -ENOMEM; 777 } 778 fw_dump.cpu_notes_buf = __pa(note_buf); 779 780 pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", 781 (num_cpus * sizeof(note_buf_t)), note_buf); 782 783 if (fw_dump.fadumphdr_addr) 784 fdh = __va(fw_dump.fadumphdr_addr); 785 786 for (i = 0; i < num_cpus; i++) { 787 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) { 788 printk(KERN_ERR "Unable to read CPU state data\n"); 789 rc = -ENOENT; 790 goto error_out; 791 } 792 /* Lower 4 bytes of reg_value contains logical cpu id */ 793 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK; 794 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { 795 SKIP_TO_NEXT_CPU(reg_entry); 796 continue; 797 } 798 pr_debug("Reading register data for cpu %d...\n", cpu); 799 if (fdh && fdh->crashing_cpu == cpu) { 800 regs = fdh->regs; 801 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 802 SKIP_TO_NEXT_CPU(reg_entry); 803 } else { 804 reg_entry++; 805 reg_entry = fadump_read_registers(reg_entry, ®s); 806 note_buf = fadump_regs_to_elf_notes(note_buf, ®s); 807 } 808 } 809 final_note(note_buf); 810 811 if (fdh) { 812 pr_debug("Updating elfcore header (%llx) with cpu notes\n", 813 fdh->elfcorehdr_addr); 814 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); 815 } 816 return 0; 817 818 error_out: 819 fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), 820 fw_dump.cpu_notes_buf_size); 821 fw_dump.cpu_notes_buf = 0; 822 fw_dump.cpu_notes_buf_size = 0; 823 return rc; 824 825 } 826 827 /* 828 * Validate and process the dump data stored by firmware before exporting 829 * it through '/proc/vmcore'. 830 */ 831 static int __init process_fadump(const struct fadump_mem_struct *fdm_active) 832 { 833 struct fadump_crash_info_header *fdh; 834 int rc = 0; 835 836 if (!fdm_active || !fw_dump.fadumphdr_addr) 837 return -EINVAL; 838 839 /* Check if the dump data is valid. */ 840 if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) || 841 (fdm_active->cpu_state_data.error_flags != 0) || 842 (fdm_active->rmr_region.error_flags != 0)) { 843 printk(KERN_ERR "Dump taken by platform is not valid\n"); 844 return -EINVAL; 845 } 846 if ((fdm_active->rmr_region.bytes_dumped != 847 fdm_active->rmr_region.source_len) || 848 !fdm_active->cpu_state_data.bytes_dumped) { 849 printk(KERN_ERR "Dump taken by platform is incomplete\n"); 850 return -EINVAL; 851 } 852 853 /* Validate the fadump crash info header */ 854 fdh = __va(fw_dump.fadumphdr_addr); 855 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { 856 printk(KERN_ERR "Crash info header is not valid.\n"); 857 return -EINVAL; 858 } 859 860 rc = fadump_build_cpu_notes(fdm_active); 861 if (rc) 862 return rc; 863 864 /* 865 * We are done validating dump info and elfcore header is now ready 866 * to be exported. set elfcorehdr_addr so that vmcore module will 867 * export the elfcore header through '/proc/vmcore'. 868 */ 869 elfcorehdr_addr = fdh->elfcorehdr_addr; 870 871 return 0; 872 } 873 874 static void free_crash_memory_ranges(void) 875 { 876 kfree(crash_memory_ranges); 877 crash_memory_ranges = NULL; 878 crash_memory_ranges_size = 0; 879 max_crash_mem_ranges = 0; 880 } 881 882 /* 883 * Allocate or reallocate crash memory ranges array in incremental units 884 * of PAGE_SIZE. 885 */ 886 static int allocate_crash_memory_ranges(void) 887 { 888 struct fad_crash_memory_ranges *new_array; 889 u64 new_size; 890 891 new_size = crash_memory_ranges_size + PAGE_SIZE; 892 pr_debug("Allocating %llu bytes of memory for crash memory ranges\n", 893 new_size); 894 895 new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL); 896 if (new_array == NULL) { 897 pr_err("Insufficient memory for setting up crash memory ranges\n"); 898 free_crash_memory_ranges(); 899 return -ENOMEM; 900 } 901 902 crash_memory_ranges = new_array; 903 crash_memory_ranges_size = new_size; 904 max_crash_mem_ranges = (new_size / 905 sizeof(struct fad_crash_memory_ranges)); 906 return 0; 907 } 908 909 static inline int fadump_add_crash_memory(unsigned long long base, 910 unsigned long long end) 911 { 912 u64 start, size; 913 bool is_adjacent = false; 914 915 if (base == end) 916 return 0; 917 918 /* 919 * Fold adjacent memory ranges to bring down the memory ranges/ 920 * PT_LOAD segments count. 921 */ 922 if (crash_mem_ranges) { 923 start = crash_memory_ranges[crash_mem_ranges - 1].base; 924 size = crash_memory_ranges[crash_mem_ranges - 1].size; 925 926 if ((start + size) == base) 927 is_adjacent = true; 928 } 929 if (!is_adjacent) { 930 /* resize the array on reaching the limit */ 931 if (crash_mem_ranges == max_crash_mem_ranges) { 932 int ret; 933 934 ret = allocate_crash_memory_ranges(); 935 if (ret) 936 return ret; 937 } 938 939 start = base; 940 crash_memory_ranges[crash_mem_ranges].base = start; 941 crash_mem_ranges++; 942 } 943 944 crash_memory_ranges[crash_mem_ranges - 1].size = (end - start); 945 pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", 946 (crash_mem_ranges - 1), start, end - 1, (end - start)); 947 return 0; 948 } 949 950 static int fadump_exclude_reserved_area(unsigned long long start, 951 unsigned long long end) 952 { 953 unsigned long long ra_start, ra_end; 954 int ret = 0; 955 956 ra_start = fw_dump.reserve_dump_area_start; 957 ra_end = ra_start + fw_dump.reserve_dump_area_size; 958 959 if ((ra_start < end) && (ra_end > start)) { 960 if ((start < ra_start) && (end > ra_end)) { 961 ret = fadump_add_crash_memory(start, ra_start); 962 if (ret) 963 return ret; 964 965 ret = fadump_add_crash_memory(ra_end, end); 966 } else if (start < ra_start) { 967 ret = fadump_add_crash_memory(start, ra_start); 968 } else if (ra_end < end) { 969 ret = fadump_add_crash_memory(ra_end, end); 970 } 971 } else 972 ret = fadump_add_crash_memory(start, end); 973 974 return ret; 975 } 976 977 static int fadump_init_elfcore_header(char *bufp) 978 { 979 struct elfhdr *elf; 980 981 elf = (struct elfhdr *) bufp; 982 bufp += sizeof(struct elfhdr); 983 memcpy(elf->e_ident, ELFMAG, SELFMAG); 984 elf->e_ident[EI_CLASS] = ELF_CLASS; 985 elf->e_ident[EI_DATA] = ELF_DATA; 986 elf->e_ident[EI_VERSION] = EV_CURRENT; 987 elf->e_ident[EI_OSABI] = ELF_OSABI; 988 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); 989 elf->e_type = ET_CORE; 990 elf->e_machine = ELF_ARCH; 991 elf->e_version = EV_CURRENT; 992 elf->e_entry = 0; 993 elf->e_phoff = sizeof(struct elfhdr); 994 elf->e_shoff = 0; 995 #if defined(_CALL_ELF) 996 elf->e_flags = _CALL_ELF; 997 #else 998 elf->e_flags = 0; 999 #endif 1000 elf->e_ehsize = sizeof(struct elfhdr); 1001 elf->e_phentsize = sizeof(struct elf_phdr); 1002 elf->e_phnum = 0; 1003 elf->e_shentsize = 0; 1004 elf->e_shnum = 0; 1005 elf->e_shstrndx = 0; 1006 1007 return 0; 1008 } 1009 1010 /* 1011 * Traverse through memblock structure and setup crash memory ranges. These 1012 * ranges will be used create PT_LOAD program headers in elfcore header. 1013 */ 1014 static int fadump_setup_crash_memory_ranges(void) 1015 { 1016 struct memblock_region *reg; 1017 unsigned long long start, end; 1018 int ret; 1019 1020 pr_debug("Setup crash memory ranges.\n"); 1021 crash_mem_ranges = 0; 1022 1023 /* 1024 * add the first memory chunk (RMA_START through boot_memory_size) as 1025 * a separate memory chunk. The reason is, at the time crash firmware 1026 * will move the content of this memory chunk to different location 1027 * specified during fadump registration. We need to create a separate 1028 * program header for this chunk with the correct offset. 1029 */ 1030 ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); 1031 if (ret) 1032 return ret; 1033 1034 for_each_memblock(memory, reg) { 1035 start = (unsigned long long)reg->base; 1036 end = start + (unsigned long long)reg->size; 1037 1038 /* 1039 * skip the first memory chunk that is already added (RMA_START 1040 * through boot_memory_size). This logic needs a relook if and 1041 * when RMA_START changes to a non-zero value. 1042 */ 1043 BUILD_BUG_ON(RMA_START != 0); 1044 if (start < fw_dump.boot_memory_size) { 1045 if (end > fw_dump.boot_memory_size) 1046 start = fw_dump.boot_memory_size; 1047 else 1048 continue; 1049 } 1050 1051 /* add this range excluding the reserved dump area. */ 1052 ret = fadump_exclude_reserved_area(start, end); 1053 if (ret) 1054 return ret; 1055 } 1056 1057 return 0; 1058 } 1059 1060 /* 1061 * If the given physical address falls within the boot memory region then 1062 * return the relocated address that points to the dump region reserved 1063 * for saving initial boot memory contents. 1064 */ 1065 static inline unsigned long fadump_relocate(unsigned long paddr) 1066 { 1067 if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) 1068 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr; 1069 else 1070 return paddr; 1071 } 1072 1073 static int fadump_create_elfcore_headers(char *bufp) 1074 { 1075 struct elfhdr *elf; 1076 struct elf_phdr *phdr; 1077 int i; 1078 1079 fadump_init_elfcore_header(bufp); 1080 elf = (struct elfhdr *)bufp; 1081 bufp += sizeof(struct elfhdr); 1082 1083 /* 1084 * setup ELF PT_NOTE, place holder for cpu notes info. The notes info 1085 * will be populated during second kernel boot after crash. Hence 1086 * this PT_NOTE will always be the first elf note. 1087 * 1088 * NOTE: Any new ELF note addition should be placed after this note. 1089 */ 1090 phdr = (struct elf_phdr *)bufp; 1091 bufp += sizeof(struct elf_phdr); 1092 phdr->p_type = PT_NOTE; 1093 phdr->p_flags = 0; 1094 phdr->p_vaddr = 0; 1095 phdr->p_align = 0; 1096 1097 phdr->p_offset = 0; 1098 phdr->p_paddr = 0; 1099 phdr->p_filesz = 0; 1100 phdr->p_memsz = 0; 1101 1102 (elf->e_phnum)++; 1103 1104 /* setup ELF PT_NOTE for vmcoreinfo */ 1105 phdr = (struct elf_phdr *)bufp; 1106 bufp += sizeof(struct elf_phdr); 1107 phdr->p_type = PT_NOTE; 1108 phdr->p_flags = 0; 1109 phdr->p_vaddr = 0; 1110 phdr->p_align = 0; 1111 1112 phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); 1113 phdr->p_offset = phdr->p_paddr; 1114 phdr->p_memsz = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; 1115 1116 /* Increment number of program headers. */ 1117 (elf->e_phnum)++; 1118 1119 /* setup PT_LOAD sections. */ 1120 1121 for (i = 0; i < crash_mem_ranges; i++) { 1122 unsigned long long mbase, msize; 1123 mbase = crash_memory_ranges[i].base; 1124 msize = crash_memory_ranges[i].size; 1125 1126 if (!msize) 1127 continue; 1128 1129 phdr = (struct elf_phdr *)bufp; 1130 bufp += sizeof(struct elf_phdr); 1131 phdr->p_type = PT_LOAD; 1132 phdr->p_flags = PF_R|PF_W|PF_X; 1133 phdr->p_offset = mbase; 1134 1135 if (mbase == RMA_START) { 1136 /* 1137 * The entire RMA region will be moved by firmware 1138 * to the specified destination_address. Hence set 1139 * the correct offset. 1140 */ 1141 phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address); 1142 } 1143 1144 phdr->p_paddr = mbase; 1145 phdr->p_vaddr = (unsigned long)__va(mbase); 1146 phdr->p_filesz = msize; 1147 phdr->p_memsz = msize; 1148 phdr->p_align = 0; 1149 1150 /* Increment number of program headers. */ 1151 (elf->e_phnum)++; 1152 } 1153 return 0; 1154 } 1155 1156 static unsigned long init_fadump_header(unsigned long addr) 1157 { 1158 struct fadump_crash_info_header *fdh; 1159 1160 if (!addr) 1161 return 0; 1162 1163 fw_dump.fadumphdr_addr = addr; 1164 fdh = __va(addr); 1165 addr += sizeof(struct fadump_crash_info_header); 1166 1167 memset(fdh, 0, sizeof(struct fadump_crash_info_header)); 1168 fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; 1169 fdh->elfcorehdr_addr = addr; 1170 /* We will set the crashing cpu id in crash_fadump() during crash. */ 1171 fdh->crashing_cpu = CPU_UNKNOWN; 1172 1173 return addr; 1174 } 1175 1176 static int register_fadump(void) 1177 { 1178 unsigned long addr; 1179 void *vaddr; 1180 int ret; 1181 1182 /* 1183 * If no memory is reserved then we can not register for firmware- 1184 * assisted dump. 1185 */ 1186 if (!fw_dump.reserve_dump_area_size) 1187 return -ENODEV; 1188 1189 ret = fadump_setup_crash_memory_ranges(); 1190 if (ret) 1191 return ret; 1192 1193 addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len); 1194 /* Initialize fadump crash info header. */ 1195 addr = init_fadump_header(addr); 1196 vaddr = __va(addr); 1197 1198 pr_debug("Creating ELF core headers at %#016lx\n", addr); 1199 fadump_create_elfcore_headers(vaddr); 1200 1201 /* register the future kernel dump with firmware. */ 1202 return register_fw_dump(&fdm); 1203 } 1204 1205 static int fadump_unregister_dump(struct fadump_mem_struct *fdm) 1206 { 1207 int rc = 0; 1208 unsigned int wait_time; 1209 1210 pr_debug("Un-register firmware-assisted dump\n"); 1211 1212 /* TODO: Add upper time limit for the delay */ 1213 do { 1214 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1215 FADUMP_UNREGISTER, fdm, 1216 sizeof(struct fadump_mem_struct)); 1217 1218 wait_time = rtas_busy_delay_time(rc); 1219 if (wait_time) 1220 mdelay(wait_time); 1221 } while (wait_time); 1222 1223 if (rc) { 1224 printk(KERN_ERR "Failed to un-register firmware-assisted dump." 1225 " unexpected error(%d).\n", rc); 1226 return rc; 1227 } 1228 fw_dump.dump_registered = 0; 1229 return 0; 1230 } 1231 1232 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) 1233 { 1234 int rc = 0; 1235 unsigned int wait_time; 1236 1237 pr_debug("Invalidating firmware-assisted dump registration\n"); 1238 1239 /* TODO: Add upper time limit for the delay */ 1240 do { 1241 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, 1242 FADUMP_INVALIDATE, fdm, 1243 sizeof(struct fadump_mem_struct)); 1244 1245 wait_time = rtas_busy_delay_time(rc); 1246 if (wait_time) 1247 mdelay(wait_time); 1248 } while (wait_time); 1249 1250 if (rc) { 1251 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc); 1252 return rc; 1253 } 1254 fw_dump.dump_active = 0; 1255 fdm_active = NULL; 1256 return 0; 1257 } 1258 1259 void fadump_cleanup(void) 1260 { 1261 /* Invalidate the registration only if dump is active. */ 1262 if (fw_dump.dump_active) { 1263 init_fadump_mem_struct(&fdm, 1264 be64_to_cpu(fdm_active->cpu_state_data.destination_address)); 1265 fadump_invalidate_dump(&fdm); 1266 } else if (fw_dump.dump_registered) { 1267 /* Un-register Firmware-assisted dump if it was registered. */ 1268 fadump_unregister_dump(&fdm); 1269 free_crash_memory_ranges(); 1270 } 1271 } 1272 1273 static void fadump_free_reserved_memory(unsigned long start_pfn, 1274 unsigned long end_pfn) 1275 { 1276 unsigned long pfn; 1277 unsigned long time_limit = jiffies + HZ; 1278 1279 pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", 1280 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); 1281 1282 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1283 free_reserved_page(pfn_to_page(pfn)); 1284 1285 if (time_after(jiffies, time_limit)) { 1286 cond_resched(); 1287 time_limit = jiffies + HZ; 1288 } 1289 } 1290 } 1291 1292 /* 1293 * Skip memory holes and free memory that was actually reserved. 1294 */ 1295 static void fadump_release_reserved_area(unsigned long start, unsigned long end) 1296 { 1297 struct memblock_region *reg; 1298 unsigned long tstart, tend; 1299 unsigned long start_pfn = PHYS_PFN(start); 1300 unsigned long end_pfn = PHYS_PFN(end); 1301 1302 for_each_memblock(memory, reg) { 1303 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg)); 1304 tend = min(end_pfn, memblock_region_memory_end_pfn(reg)); 1305 if (tstart < tend) { 1306 fadump_free_reserved_memory(tstart, tend); 1307 1308 if (tend == end_pfn) 1309 break; 1310 1311 start_pfn = tend + 1; 1312 } 1313 } 1314 } 1315 1316 /* 1317 * Release the memory that was reserved in early boot to preserve the memory 1318 * contents. The released memory will be available for general use. 1319 */ 1320 static void fadump_release_memory(unsigned long begin, unsigned long end) 1321 { 1322 unsigned long ra_start, ra_end; 1323 1324 ra_start = fw_dump.reserve_dump_area_start; 1325 ra_end = ra_start + fw_dump.reserve_dump_area_size; 1326 1327 /* 1328 * exclude the dump reserve area. Will reuse it for next 1329 * fadump registration. 1330 */ 1331 if (begin < ra_end && end > ra_start) { 1332 if (begin < ra_start) 1333 fadump_release_reserved_area(begin, ra_start); 1334 if (end > ra_end) 1335 fadump_release_reserved_area(ra_end, end); 1336 } else 1337 fadump_release_reserved_area(begin, end); 1338 } 1339 1340 static void fadump_invalidate_release_mem(void) 1341 { 1342 unsigned long reserved_area_start, reserved_area_end; 1343 unsigned long destination_address; 1344 1345 mutex_lock(&fadump_mutex); 1346 if (!fw_dump.dump_active) { 1347 mutex_unlock(&fadump_mutex); 1348 return; 1349 } 1350 1351 destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address); 1352 fadump_cleanup(); 1353 mutex_unlock(&fadump_mutex); 1354 1355 /* 1356 * Save the current reserved memory bounds we will require them 1357 * later for releasing the memory for general use. 1358 */ 1359 reserved_area_start = fw_dump.reserve_dump_area_start; 1360 reserved_area_end = reserved_area_start + 1361 fw_dump.reserve_dump_area_size; 1362 /* 1363 * Setup reserve_dump_area_start and its size so that we can 1364 * reuse this reserved memory for Re-registration. 1365 */ 1366 fw_dump.reserve_dump_area_start = destination_address; 1367 fw_dump.reserve_dump_area_size = get_fadump_area_size(); 1368 1369 fadump_release_memory(reserved_area_start, reserved_area_end); 1370 if (fw_dump.cpu_notes_buf) { 1371 fadump_cpu_notes_buf_free( 1372 (unsigned long)__va(fw_dump.cpu_notes_buf), 1373 fw_dump.cpu_notes_buf_size); 1374 fw_dump.cpu_notes_buf = 0; 1375 fw_dump.cpu_notes_buf_size = 0; 1376 } 1377 /* Initialize the kernel dump memory structure for FAD registration. */ 1378 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1379 } 1380 1381 static ssize_t fadump_release_memory_store(struct kobject *kobj, 1382 struct kobj_attribute *attr, 1383 const char *buf, size_t count) 1384 { 1385 int input = -1; 1386 1387 if (!fw_dump.dump_active) 1388 return -EPERM; 1389 1390 if (kstrtoint(buf, 0, &input)) 1391 return -EINVAL; 1392 1393 if (input == 1) { 1394 /* 1395 * Take away the '/proc/vmcore'. We are releasing the dump 1396 * memory, hence it will not be valid anymore. 1397 */ 1398 #ifdef CONFIG_PROC_VMCORE 1399 vmcore_cleanup(); 1400 #endif 1401 fadump_invalidate_release_mem(); 1402 1403 } else 1404 return -EINVAL; 1405 return count; 1406 } 1407 1408 static ssize_t fadump_enabled_show(struct kobject *kobj, 1409 struct kobj_attribute *attr, 1410 char *buf) 1411 { 1412 return sprintf(buf, "%d\n", fw_dump.fadump_enabled); 1413 } 1414 1415 static ssize_t fadump_register_show(struct kobject *kobj, 1416 struct kobj_attribute *attr, 1417 char *buf) 1418 { 1419 return sprintf(buf, "%d\n", fw_dump.dump_registered); 1420 } 1421 1422 static ssize_t fadump_register_store(struct kobject *kobj, 1423 struct kobj_attribute *attr, 1424 const char *buf, size_t count) 1425 { 1426 int ret = 0; 1427 int input = -1; 1428 1429 if (!fw_dump.fadump_enabled || fdm_active) 1430 return -EPERM; 1431 1432 if (kstrtoint(buf, 0, &input)) 1433 return -EINVAL; 1434 1435 mutex_lock(&fadump_mutex); 1436 1437 switch (input) { 1438 case 0: 1439 if (fw_dump.dump_registered == 0) { 1440 goto unlock_out; 1441 } 1442 /* Un-register Firmware-assisted dump */ 1443 fadump_unregister_dump(&fdm); 1444 break; 1445 case 1: 1446 if (fw_dump.dump_registered == 1) { 1447 ret = -EEXIST; 1448 goto unlock_out; 1449 } 1450 /* Register Firmware-assisted dump */ 1451 ret = register_fadump(); 1452 break; 1453 default: 1454 ret = -EINVAL; 1455 break; 1456 } 1457 1458 unlock_out: 1459 mutex_unlock(&fadump_mutex); 1460 return ret < 0 ? ret : count; 1461 } 1462 1463 static int fadump_region_show(struct seq_file *m, void *private) 1464 { 1465 const struct fadump_mem_struct *fdm_ptr; 1466 1467 if (!fw_dump.fadump_enabled) 1468 return 0; 1469 1470 mutex_lock(&fadump_mutex); 1471 if (fdm_active) 1472 fdm_ptr = fdm_active; 1473 else { 1474 mutex_unlock(&fadump_mutex); 1475 fdm_ptr = &fdm; 1476 } 1477 1478 seq_printf(m, 1479 "CPU : [%#016llx-%#016llx] %#llx bytes, " 1480 "Dumped: %#llx\n", 1481 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address), 1482 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) + 1483 be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1, 1484 be64_to_cpu(fdm_ptr->cpu_state_data.source_len), 1485 be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped)); 1486 seq_printf(m, 1487 "HPTE: [%#016llx-%#016llx] %#llx bytes, " 1488 "Dumped: %#llx\n", 1489 be64_to_cpu(fdm_ptr->hpte_region.destination_address), 1490 be64_to_cpu(fdm_ptr->hpte_region.destination_address) + 1491 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1, 1492 be64_to_cpu(fdm_ptr->hpte_region.source_len), 1493 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped)); 1494 seq_printf(m, 1495 "DUMP: [%#016llx-%#016llx] %#llx bytes, " 1496 "Dumped: %#llx\n", 1497 be64_to_cpu(fdm_ptr->rmr_region.destination_address), 1498 be64_to_cpu(fdm_ptr->rmr_region.destination_address) + 1499 be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1, 1500 be64_to_cpu(fdm_ptr->rmr_region.source_len), 1501 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); 1502 1503 if (!fdm_active || 1504 (fw_dump.reserve_dump_area_start == 1505 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address))) 1506 goto out; 1507 1508 /* Dump is active. Show reserved memory region. */ 1509 seq_printf(m, 1510 " : [%#016llx-%#016llx] %#llx bytes, " 1511 "Dumped: %#llx\n", 1512 (unsigned long long)fw_dump.reserve_dump_area_start, 1513 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1, 1514 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1515 fw_dump.reserve_dump_area_start, 1516 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1517 fw_dump.reserve_dump_area_start); 1518 out: 1519 if (fdm_active) 1520 mutex_unlock(&fadump_mutex); 1521 return 0; 1522 } 1523 1524 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, 1525 0200, NULL, 1526 fadump_release_memory_store); 1527 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, 1528 0444, fadump_enabled_show, 1529 NULL); 1530 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, 1531 0644, fadump_register_show, 1532 fadump_register_store); 1533 1534 static int fadump_region_open(struct inode *inode, struct file *file) 1535 { 1536 return single_open(file, fadump_region_show, inode->i_private); 1537 } 1538 1539 static const struct file_operations fadump_region_fops = { 1540 .open = fadump_region_open, 1541 .read = seq_read, 1542 .llseek = seq_lseek, 1543 .release = single_release, 1544 }; 1545 1546 static void fadump_init_files(void) 1547 { 1548 struct dentry *debugfs_file; 1549 int rc = 0; 1550 1551 rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); 1552 if (rc) 1553 printk(KERN_ERR "fadump: unable to create sysfs file" 1554 " fadump_enabled (%d)\n", rc); 1555 1556 rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); 1557 if (rc) 1558 printk(KERN_ERR "fadump: unable to create sysfs file" 1559 " fadump_registered (%d)\n", rc); 1560 1561 debugfs_file = debugfs_create_file("fadump_region", 0444, 1562 powerpc_debugfs_root, NULL, 1563 &fadump_region_fops); 1564 if (!debugfs_file) 1565 printk(KERN_ERR "fadump: unable to create debugfs file" 1566 " fadump_region\n"); 1567 1568 if (fw_dump.dump_active) { 1569 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); 1570 if (rc) 1571 printk(KERN_ERR "fadump: unable to create sysfs file" 1572 " fadump_release_mem (%d)\n", rc); 1573 } 1574 return; 1575 } 1576 1577 /* 1578 * Prepare for firmware-assisted dump. 1579 */ 1580 int __init setup_fadump(void) 1581 { 1582 if (!fw_dump.fadump_enabled) 1583 return 0; 1584 1585 if (!fw_dump.fadump_supported) { 1586 printk(KERN_ERR "Firmware-assisted dump is not supported on" 1587 " this hardware\n"); 1588 return 0; 1589 } 1590 1591 fadump_show_config(); 1592 /* 1593 * If dump data is available then see if it is valid and prepare for 1594 * saving it to the disk. 1595 */ 1596 if (fw_dump.dump_active) { 1597 /* 1598 * if dump process fails then invalidate the registration 1599 * and release memory before proceeding for re-registration. 1600 */ 1601 if (process_fadump(fdm_active) < 0) 1602 fadump_invalidate_release_mem(); 1603 } 1604 /* Initialize the kernel dump memory structure for FAD registration. */ 1605 else if (fw_dump.reserve_dump_area_size) 1606 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); 1607 fadump_init_files(); 1608 1609 return 1; 1610 } 1611 subsys_initcall(setup_fadump); 1612