arch/powerpc/kernel/fadump.c

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