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         __be32 *sections;
  59         int i, num_sections;
  60         unsigned long 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",
 293                                 (unsigned long long)memory_limit);
 294         }
 295         if (memory_limit)
 296                 memory_boundary = memory_limit;
 297         else
 298                 memory_boundary = memblock_end_of_DRAM();
 299
 300         if (fw_dump.dump_active) {
 301                 printk(KERN_INFO "Firmware-assisted dump is active.\n");
 302                 /*
 303                  * If last boot has crashed then reserve all the memory
 304                  * above boot_memory_size so that we don't touch it until
 305                  * dump is written to disk by userspace tool. This memory
 306                  * will be released for general use once the dump is saved.
 307                  */
 308                 base = fw_dump.boot_memory_size;
 309                 size = memory_boundary - base;
 310                 memblock_reserve(base, size);
 311                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
 312                                 "for saving crash dump\n",
 313                                 (unsigned long)(size >> 20),
 314                                 (unsigned long)(base >> 20));
 315
 316                 fw_dump.fadumphdr_addr =
 317                                 fdm_active->rmr_region.destination_address +
 318                                 fdm_active->rmr_region.source_len;
 319                 pr_debug("fadumphdr_addr = %p\n",
 320                                 (void *) fw_dump.fadumphdr_addr);
 321         } else {
 322                 /* Reserve the memory at the top of memory. */
 323                 size = get_fadump_area_size();
 324                 base = memory_boundary - size;
 325                 memblock_reserve(base, size);
 326                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
 327                                 "for firmware-assisted dump\n",
 328                                 (unsigned long)(size >> 20),
 329                                 (unsigned long)(base >> 20));
 330         }
 331         fw_dump.reserve_dump_area_start = base;
 332         fw_dump.reserve_dump_area_size = size;
 333         return 1;
 334 }
 335
 336 /* Look for fadump= cmdline option. */
 337 static int __init early_fadump_param(char *p)
 338 {
 339         if (!p)
 340                 return 1;
 341
 342         if (strncmp(p, "on", 2) == 0)
 343                 fw_dump.fadump_enabled = 1;
 344         else if (strncmp(p, "off", 3) == 0)
 345                 fw_dump.fadump_enabled = 0;
 346
 347         return 0;
 348 }
 349 early_param("fadump", early_fadump_param);
 350
 351 /* Look for fadump_reserve_mem= cmdline option */
 352 static int __init early_fadump_reserve_mem(char *p)
 353 {
 354         if (p)
 355                 fw_dump.reserve_bootvar = memparse(p, &p);
 356         return 0;
 357 }
 358 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
 359
 360 static void register_fw_dump(struct fadump_mem_struct *fdm)
 361 {
 362         int rc;
 363         unsigned int wait_time;
 364
 365         pr_debug("Registering for firmware-assisted kernel dump...\n");
 366
 367         /* TODO: Add upper time limit for the delay */
 368         do {
 369                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 370                         FADUMP_REGISTER, fdm,
 371                         sizeof(struct fadump_mem_struct));
 372
 373                 wait_time = rtas_busy_delay_time(rc);
 374                 if (wait_time)
 375                         mdelay(wait_time);
 376
 377         } while (wait_time);
 378
 379         switch (rc) {
 380         case -1:
 381                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 382                         " dump. Hardware Error(%d).\n", rc);
 383                 break;
 384         case -3:
 385                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 386                         " dump. Parameter Error(%d).\n", rc);
 387                 break;
 388         case -9:
 389                 printk(KERN_ERR "firmware-assisted kernel dump is already "
 390                         " registered.");
 391                 fw_dump.dump_registered = 1;
 392                 break;
 393         case 0:
 394                 printk(KERN_INFO "firmware-assisted kernel dump registration"
 395                         " is successful\n");
 396                 fw_dump.dump_registered = 1;
 397                 break;
 398         }
 399 }
 400
 401 void crash_fadump(struct pt_regs *regs, const char *str)
 402 {
 403         struct fadump_crash_info_header *fdh = NULL;
 404
 405         if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
 406                 return;
 407
 408         fdh = __va(fw_dump.fadumphdr_addr);
 409         crashing_cpu = smp_processor_id();
 410         fdh->crashing_cpu = crashing_cpu;
 411         crash_save_vmcoreinfo();
 412
 413         if (regs)
 414                 fdh->regs = *regs;
 415         else
 416                 ppc_save_regs(&fdh->regs);
 417
 418         fdh->cpu_online_mask = *cpu_online_mask;
 419
 420         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
 421         rtas_os_term((char *)str);
 422 }
 423
 424 #define GPR_MASK        0xffffff0000000000
 425 static inline int fadump_gpr_index(u64 id)
 426 {
 427         int i = -1;
 428         char str[3];
 429
 430         if ((id & GPR_MASK) == REG_ID("GPR")) {
 431                 /* get the digits at the end */
 432                 id &= ~GPR_MASK;
 433                 id >>= 24;
 434                 str[2] = '\0';
 435                 str[1] = id & 0xff;
 436                 str[0] = (id >> 8) & 0xff;
 437                 sscanf(str, "%d", &i);
 438                 if (i > 31)
 439                         i = -1;
 440         }
 441         return i;
 442 }
 443
 444 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
 445                                                                 u64 reg_val)
 446 {
 447         int i;
 448
 449         i = fadump_gpr_index(reg_id);
 450         if (i >= 0)
 451                 regs->gpr[i] = (unsigned long)reg_val;
 452         else if (reg_id == REG_ID("NIA"))
 453                 regs->nip = (unsigned long)reg_val;
 454         else if (reg_id == REG_ID("MSR"))
 455                 regs->msr = (unsigned long)reg_val;
 456         else if (reg_id == REG_ID("CTR"))
 457                 regs->ctr = (unsigned long)reg_val;
 458         else if (reg_id == REG_ID("LR"))
 459                 regs->link = (unsigned long)reg_val;
 460         else if (reg_id == REG_ID("XER"))
 461                 regs->xer = (unsigned long)reg_val;
 462         else if (reg_id == REG_ID("CR"))
 463                 regs->ccr = (unsigned long)reg_val;
 464         else if (reg_id == REG_ID("DAR"))
 465                 regs->dar = (unsigned long)reg_val;
 466         else if (reg_id == REG_ID("DSISR"))
 467                 regs->dsisr = (unsigned long)reg_val;
 468 }
 469
 470 static struct fadump_reg_entry*
 471 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 472 {
 473         memset(regs, 0, sizeof(struct pt_regs));
 474
 475         while (reg_entry->reg_id != REG_ID("CPUEND")) {
 476                 fadump_set_regval(regs, reg_entry->reg_id,
 477                                         reg_entry->reg_value);
 478                 reg_entry++;
 479         }
 480         reg_entry++;
 481         return reg_entry;
 482 }
 483
 484 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
 485                                                 void *data, size_t data_len)
 486 {
 487         struct elf_note note;
 488
 489         note.n_namesz = strlen(name) + 1;
 490         note.n_descsz = data_len;
 491         note.n_type   = type;
 492         memcpy(buf, &note, sizeof(note));
 493         buf += (sizeof(note) + 3)/4;
 494         memcpy(buf, name, note.n_namesz);
 495         buf += (note.n_namesz + 3)/4;
 496         memcpy(buf, data, note.n_descsz);
 497         buf += (note.n_descsz + 3)/4;
 498
 499         return buf;
 500 }
 501
 502 static void fadump_final_note(u32 *buf)
 503 {
 504         struct elf_note note;
 505
 506         note.n_namesz = 0;
 507         note.n_descsz = 0;
 508         note.n_type   = 0;
 509         memcpy(buf, &note, sizeof(note));
 510 }
 511
 512 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 513 {
 514         struct elf_prstatus prstatus;
 515
 516         memset(&prstatus, 0, sizeof(prstatus));
 517         /*
 518          * FIXME: How do i get PID? Do I really need it?
 519          * prstatus.pr_pid = ????
 520          */
 521         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 522         buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
 523                                 &prstatus, sizeof(prstatus));
 524         return buf;
 525 }
 526
 527 static void fadump_update_elfcore_header(char *bufp)
 528 {
 529         struct elfhdr *elf;
 530         struct elf_phdr *phdr;
 531
 532         elf = (struct elfhdr *)bufp;
 533         bufp += sizeof(struct elfhdr);
 534
 535         /* First note is a place holder for cpu notes info. */
 536         phdr = (struct elf_phdr *)bufp;
 537
 538         if (phdr->p_type == PT_NOTE) {
 539                 phdr->p_paddr = fw_dump.cpu_notes_buf;
 540                 phdr->p_offset  = phdr->p_paddr;
 541                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
 542                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
 543         }
 544         return;
 545 }
 546
 547 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
 548 {
 549         void *vaddr;
 550         struct page *page;
 551         unsigned long order, count, i;
 552
 553         order = get_order(size);
 554         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
 555         if (!vaddr)
 556                 return NULL;
 557
 558         count = 1 << order;
 559         page = virt_to_page(vaddr);
 560         for (i = 0; i < count; i++)
 561                 SetPageReserved(page + i);
 562         return vaddr;
 563 }
 564
 565 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
 566 {
 567         struct page *page;
 568         unsigned long order, count, i;
 569
 570         order = get_order(size);
 571         count = 1 << order;
 572         page = virt_to_page(vaddr);
 573         for (i = 0; i < count; i++)
 574                 ClearPageReserved(page + i);
 575         __free_pages(page, order);
 576 }
 577
 578 /*
 579  * Read CPU state dump data and convert it into ELF notes.
 580  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
 581  * used to access the data to allow for additional fields to be added without
 582  * affecting compatibility. Each list of registers for a CPU starts with
 583  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
 584  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
 585  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
 586  * of register value. For more details refer to PAPR document.
 587  *
 588  * Only for the crashing cpu we ignore the CPU dump data and get exact
 589  * state from fadump crash info structure populated by first kernel at the
 590  * time of crash.
 591  */
 592 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 593 {
 594         struct fadump_reg_save_area_header *reg_header;
 595         struct fadump_reg_entry *reg_entry;
 596         struct fadump_crash_info_header *fdh = NULL;
 597         void *vaddr;
 598         unsigned long addr;
 599         u32 num_cpus, *note_buf;
 600         struct pt_regs regs;
 601         int i, rc = 0, cpu = 0;
 602
 603         if (!fdm->cpu_state_data.bytes_dumped)
 604                 return -EINVAL;
 605
 606         addr = fdm->cpu_state_data.destination_address;
 607         vaddr = __va(addr);
 608
 609         reg_header = vaddr;
 610         if (reg_header->magic_number != REGSAVE_AREA_MAGIC) {
 611                 printk(KERN_ERR "Unable to read register save area.\n");
 612                 return -ENOENT;
 613         }
 614         pr_debug("--------CPU State Data------------\n");
 615         pr_debug("Magic Number: %llx\n", reg_header->magic_number);
 616         pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset);
 617
 618         vaddr += reg_header->num_cpu_offset;
 619         num_cpus = *((u32 *)(vaddr));
 620         pr_debug("NumCpus     : %u\n", num_cpus);
 621         vaddr += sizeof(u32);
 622         reg_entry = (struct fadump_reg_entry *)vaddr;
 623
 624         /* Allocate buffer to hold cpu crash notes. */
 625         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
 626         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
 627         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
 628         if (!note_buf) {
 629                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
 630                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
 631                 return -ENOMEM;
 632         }
 633         fw_dump.cpu_notes_buf = __pa(note_buf);
 634
 635         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
 636                         (num_cpus * sizeof(note_buf_t)), note_buf);
 637
 638         if (fw_dump.fadumphdr_addr)
 639                 fdh = __va(fw_dump.fadumphdr_addr);
 640
 641         for (i = 0; i < num_cpus; i++) {
 642                 if (reg_entry->reg_id != REG_ID("CPUSTRT")) {
 643                         printk(KERN_ERR "Unable to read CPU state data\n");
 644                         rc = -ENOENT;
 645                         goto error_out;
 646                 }
 647                 /* Lower 4 bytes of reg_value contains logical cpu id */
 648                 cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK;
 649                 if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
 650                         SKIP_TO_NEXT_CPU(reg_entry);
 651                         continue;
 652                 }
 653                 pr_debug("Reading register data for cpu %d...\n", cpu);
 654                 if (fdh && fdh->crashing_cpu == cpu) {
 655                         regs = fdh->regs;
 656                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 657                         SKIP_TO_NEXT_CPU(reg_entry);
 658                 } else {
 659                         reg_entry++;
 660                         reg_entry = fadump_read_registers(reg_entry, &regs);
 661                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 662                 }
 663         }
 664         fadump_final_note(note_buf);
 665
 666         pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 667                                                         fdh->elfcorehdr_addr);
 668         fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 669         return 0;
 670
 671 error_out:
 672         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 673                                         fw_dump.cpu_notes_buf_size);
 674         fw_dump.cpu_notes_buf = 0;
 675         fw_dump.cpu_notes_buf_size = 0;
 676         return rc;
 677
 678 }
 679
 680 /*
 681  * Validate and process the dump data stored by firmware before exporting
 682  * it through '/proc/vmcore'.
 683  */
 684 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 685 {
 686         struct fadump_crash_info_header *fdh;
 687         int rc = 0;
 688
 689         if (!fdm_active || !fw_dump.fadumphdr_addr)
 690                 return -EINVAL;
 691
 692         /* Check if the dump data is valid. */
 693         if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
 694                         (fdm_active->cpu_state_data.error_flags != 0) ||
 695                         (fdm_active->rmr_region.error_flags != 0)) {
 696                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 697                 return -EINVAL;
 698         }
 699         if ((fdm_active->rmr_region.bytes_dumped !=
 700                         fdm_active->rmr_region.source_len) ||
 701                         !fdm_active->cpu_state_data.bytes_dumped) {
 702                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 703                 return -EINVAL;
 704         }
 705
 706         /* Validate the fadump crash info header */
 707         fdh = __va(fw_dump.fadumphdr_addr);
 708         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 709                 printk(KERN_ERR "Crash info header is not valid.\n");
 710                 return -EINVAL;
 711         }
 712
 713         rc = fadump_build_cpu_notes(fdm_active);
 714         if (rc)
 715                 return rc;
 716
 717         /*
 718          * We are done validating dump info and elfcore header is now ready
 719          * to be exported. set elfcorehdr_addr so that vmcore module will
 720          * export the elfcore header through '/proc/vmcore'.
 721          */
 722         elfcorehdr_addr = fdh->elfcorehdr_addr;
 723
 724         return 0;
 725 }
 726
 727 static inline void fadump_add_crash_memory(unsigned long long base,
 728                                         unsigned long long end)
 729 {
 730         if (base == end)
 731                 return;
 732
 733         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 734                 crash_mem_ranges, base, end - 1, (end - base));
 735         crash_memory_ranges[crash_mem_ranges].base = base;
 736         crash_memory_ranges[crash_mem_ranges].size = end - base;
 737         crash_mem_ranges++;
 738 }
 739
 740 static void fadump_exclude_reserved_area(unsigned long long start,
 741                                         unsigned long long end)
 742 {
 743         unsigned long long ra_start, ra_end;
 744
 745         ra_start = fw_dump.reserve_dump_area_start;
 746         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 747
 748         if ((ra_start < end) && (ra_end > start)) {
 749                 if ((start < ra_start) && (end > ra_end)) {
 750                         fadump_add_crash_memory(start, ra_start);
 751                         fadump_add_crash_memory(ra_end, end);
 752                 } else if (start < ra_start) {
 753                         fadump_add_crash_memory(start, ra_start);
 754                 } else if (ra_end < end) {
 755                         fadump_add_crash_memory(ra_end, end);
 756                 }
 757         } else
 758                 fadump_add_crash_memory(start, end);
 759 }
 760
 761 static int fadump_init_elfcore_header(char *bufp)
 762 {
 763         struct elfhdr *elf;
 764
 765         elf = (struct elfhdr *) bufp;
 766         bufp += sizeof(struct elfhdr);
 767         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 768         elf->e_ident[EI_CLASS] = ELF_CLASS;
 769         elf->e_ident[EI_DATA] = ELF_DATA;
 770         elf->e_ident[EI_VERSION] = EV_CURRENT;
 771         elf->e_ident[EI_OSABI] = ELF_OSABI;
 772         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 773         elf->e_type = ET_CORE;
 774         elf->e_machine = ELF_ARCH;
 775         elf->e_version = EV_CURRENT;
 776         elf->e_entry = 0;
 777         elf->e_phoff = sizeof(struct elfhdr);
 778         elf->e_shoff = 0;
 779         elf->e_flags = ELF_CORE_EFLAGS;
 780         elf->e_ehsize = sizeof(struct elfhdr);
 781         elf->e_phentsize = sizeof(struct elf_phdr);
 782         elf->e_phnum = 0;
 783         elf->e_shentsize = 0;
 784         elf->e_shnum = 0;
 785         elf->e_shstrndx = 0;
 786
 787         return 0;
 788 }
 789
 790 /*
 791  * Traverse through memblock structure and setup crash memory ranges. These
 792  * ranges will be used create PT_LOAD program headers in elfcore header.
 793  */
 794 static void fadump_setup_crash_memory_ranges(void)
 795 {
 796         struct memblock_region *reg;
 797         unsigned long long start, end;
 798
 799         pr_debug("Setup crash memory ranges.\n");
 800         crash_mem_ranges = 0;
 801         /*
 802          * add the first memory chunk (RMA_START through boot_memory_size) as
 803          * a separate memory chunk. The reason is, at the time crash firmware
 804          * will move the content of this memory chunk to different location
 805          * specified during fadump registration. We need to create a separate
 806          * program header for this chunk with the correct offset.
 807          */
 808         fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 809
 810         for_each_memblock(memory, reg) {
 811                 start = (unsigned long long)reg->base;
 812                 end = start + (unsigned long long)reg->size;
 813                 if (start == RMA_START && end >= fw_dump.boot_memory_size)
 814                         start = fw_dump.boot_memory_size;
 815
 816                 /* add this range excluding the reserved dump area. */
 817                 fadump_exclude_reserved_area(start, end);
 818         }
 819 }
 820
 821 /*
 822  * If the given physical address falls within the boot memory region then
 823  * return the relocated address that points to the dump region reserved
 824  * for saving initial boot memory contents.
 825  */
 826 static inline unsigned long fadump_relocate(unsigned long paddr)
 827 {
 828         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 829                 return fdm.rmr_region.destination_address + paddr;
 830         else
 831                 return paddr;
 832 }
 833
 834 static int fadump_create_elfcore_headers(char *bufp)
 835 {
 836         struct elfhdr *elf;
 837         struct elf_phdr *phdr;
 838         int i;
 839
 840         fadump_init_elfcore_header(bufp);
 841         elf = (struct elfhdr *)bufp;
 842         bufp += sizeof(struct elfhdr);
 843
 844         /*
 845          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
 846          * will be populated during second kernel boot after crash. Hence
 847          * this PT_NOTE will always be the first elf note.
 848          *
 849          * NOTE: Any new ELF note addition should be placed after this note.
 850          */
 851         phdr = (struct elf_phdr *)bufp;
 852         bufp += sizeof(struct elf_phdr);
 853         phdr->p_type = PT_NOTE;
 854         phdr->p_flags = 0;
 855         phdr->p_vaddr = 0;
 856         phdr->p_align = 0;
 857
 858         phdr->p_offset = 0;
 859         phdr->p_paddr = 0;
 860         phdr->p_filesz = 0;
 861         phdr->p_memsz = 0;
 862
 863         (elf->e_phnum)++;
 864
 865         /* setup ELF PT_NOTE for vmcoreinfo */
 866         phdr = (struct elf_phdr *)bufp;
 867         bufp += sizeof(struct elf_phdr);
 868         phdr->p_type    = PT_NOTE;
 869         phdr->p_flags   = 0;
 870         phdr->p_vaddr   = 0;
 871         phdr->p_align   = 0;
 872
 873         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
 874         phdr->p_offset  = phdr->p_paddr;
 875         phdr->p_memsz   = vmcoreinfo_max_size;
 876         phdr->p_filesz  = vmcoreinfo_max_size;
 877
 878         /* Increment number of program headers. */
 879         (elf->e_phnum)++;
 880
 881         /* setup PT_LOAD sections. */
 882
 883         for (i = 0; i < crash_mem_ranges; i++) {
 884                 unsigned long long mbase, msize;
 885                 mbase = crash_memory_ranges[i].base;
 886                 msize = crash_memory_ranges[i].size;
 887
 888                 if (!msize)
 889                         continue;
 890
 891                 phdr = (struct elf_phdr *)bufp;
 892                 bufp += sizeof(struct elf_phdr);
 893                 phdr->p_type    = PT_LOAD;
 894                 phdr->p_flags   = PF_R|PF_W|PF_X;
 895                 phdr->p_offset  = mbase;
 896
 897                 if (mbase == RMA_START) {
 898                         /*
 899                          * The entire RMA region will be moved by firmware
 900                          * to the specified destination_address. Hence set
 901                          * the correct offset.
 902                          */
 903                         phdr->p_offset = fdm.rmr_region.destination_address;
 904                 }
 905
 906                 phdr->p_paddr = mbase;
 907                 phdr->p_vaddr = (unsigned long)__va(mbase);
 908                 phdr->p_filesz = msize;
 909                 phdr->p_memsz = msize;
 910                 phdr->p_align = 0;
 911
 912                 /* Increment number of program headers. */
 913                 (elf->e_phnum)++;
 914         }
 915         return 0;
 916 }
 917
 918 static unsigned long init_fadump_header(unsigned long addr)
 919 {
 920         struct fadump_crash_info_header *fdh;
 921
 922         if (!addr)
 923                 return 0;
 924
 925         fw_dump.fadumphdr_addr = addr;
 926         fdh = __va(addr);
 927         addr += sizeof(struct fadump_crash_info_header);
 928
 929         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
 930         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
 931         fdh->elfcorehdr_addr = addr;
 932         /* We will set the crashing cpu id in crash_fadump() during crash. */
 933         fdh->crashing_cpu = CPU_UNKNOWN;
 934
 935         return addr;
 936 }
 937
 938 static void register_fadump(void)
 939 {
 940         unsigned long addr;
 941         void *vaddr;
 942
 943         /*
 944          * If no memory is reserved then we can not register for firmware-
 945          * assisted dump.
 946          */
 947         if (!fw_dump.reserve_dump_area_size)
 948                 return;
 949
 950         fadump_setup_crash_memory_ranges();
 951
 952         addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
 953         /* Initialize fadump crash info header. */
 954         addr = init_fadump_header(addr);
 955         vaddr = __va(addr);
 956
 957         pr_debug("Creating ELF core headers at %#016lx\n", addr);
 958         fadump_create_elfcore_headers(vaddr);
 959
 960         /* register the future kernel dump with firmware. */
 961         register_fw_dump(&fdm);
 962 }
 963
 964 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
 965 {
 966         int rc = 0;
 967         unsigned int wait_time;
 968
 969         pr_debug("Un-register firmware-assisted dump\n");
 970
 971         /* TODO: Add upper time limit for the delay */
 972         do {
 973                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 974                         FADUMP_UNREGISTER, fdm,
 975                         sizeof(struct fadump_mem_struct));
 976
 977                 wait_time = rtas_busy_delay_time(rc);
 978                 if (wait_time)
 979                         mdelay(wait_time);
 980         } while (wait_time);
 981
 982         if (rc) {
 983                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
 984                         " unexpected error(%d).\n", rc);
 985                 return rc;
 986         }
 987         fw_dump.dump_registered = 0;
 988         return 0;
 989 }
 990
 991 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
 992 {
 993         int rc = 0;
 994         unsigned int wait_time;
 995
 996         pr_debug("Invalidating firmware-assisted dump registration\n");
 997
 998         /* TODO: Add upper time limit for the delay */
 999         do {
1000                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1001                         FADUMP_INVALIDATE, fdm,
1002                         sizeof(struct fadump_mem_struct));
1003
1004                 wait_time = rtas_busy_delay_time(rc);
1005                 if (wait_time)
1006                         mdelay(wait_time);
1007         } while (wait_time);
1008
1009         if (rc) {
1010                 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1011                         "rgistration. unexpected error(%d).\n", rc);
1012                 return rc;
1013         }
1014         fw_dump.dump_active = 0;
1015         fdm_active = NULL;
1016         return 0;
1017 }
1018
1019 void fadump_cleanup(void)
1020 {
1021         /* Invalidate the registration only if dump is active. */
1022         if (fw_dump.dump_active) {
1023                 init_fadump_mem_struct(&fdm,
1024                         fdm_active->cpu_state_data.destination_address);
1025                 fadump_invalidate_dump(&fdm);
1026         }
1027 }
1028
1029 /*
1030  * Release the memory that was reserved in early boot to preserve the memory
1031  * contents. The released memory will be available for general use.
1032  */
1033 static void fadump_release_memory(unsigned long begin, unsigned long end)
1034 {
1035         unsigned long addr;
1036         unsigned long ra_start, ra_end;
1037
1038         ra_start = fw_dump.reserve_dump_area_start;
1039         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1040
1041         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1042                 /*
1043                  * exclude the dump reserve area. Will reuse it for next
1044                  * fadump registration.
1045                  */
1046                 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1047                         continue;
1048
1049                 ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
1050                 init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
1051                 free_page((unsigned long)__va(addr));
1052                 totalram_pages++;
1053         }
1054 }
1055
1056 static void fadump_invalidate_release_mem(void)
1057 {
1058         unsigned long reserved_area_start, reserved_area_end;
1059         unsigned long destination_address;
1060
1061         mutex_lock(&fadump_mutex);
1062         if (!fw_dump.dump_active) {
1063                 mutex_unlock(&fadump_mutex);
1064                 return;
1065         }
1066
1067         destination_address = fdm_active->cpu_state_data.destination_address;
1068         fadump_cleanup();
1069         mutex_unlock(&fadump_mutex);
1070
1071         /*
1072          * Save the current reserved memory bounds we will require them
1073          * later for releasing the memory for general use.
1074          */
1075         reserved_area_start = fw_dump.reserve_dump_area_start;
1076         reserved_area_end = reserved_area_start +
1077                         fw_dump.reserve_dump_area_size;
1078         /*
1079          * Setup reserve_dump_area_start and its size so that we can
1080          * reuse this reserved memory for Re-registration.
1081          */
1082         fw_dump.reserve_dump_area_start = destination_address;
1083         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1084
1085         fadump_release_memory(reserved_area_start, reserved_area_end);
1086         if (fw_dump.cpu_notes_buf) {
1087                 fadump_cpu_notes_buf_free(
1088                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1089                                 fw_dump.cpu_notes_buf_size);
1090                 fw_dump.cpu_notes_buf = 0;
1091                 fw_dump.cpu_notes_buf_size = 0;
1092         }
1093         /* Initialize the kernel dump memory structure for FAD registration. */
1094         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1095 }
1096
1097 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1098                                         struct kobj_attribute *attr,
1099                                         const char *buf, size_t count)
1100 {
1101         if (!fw_dump.dump_active)
1102                 return -EPERM;
1103
1104         if (buf[0] == '1') {
1105                 /*
1106                  * Take away the '/proc/vmcore'. We are releasing the dump
1107                  * memory, hence it will not be valid anymore.
1108                  */
1109                 vmcore_cleanup();
1110                 fadump_invalidate_release_mem();
1111
1112         } else
1113                 return -EINVAL;
1114         return count;
1115 }
1116
1117 static ssize_t fadump_enabled_show(struct kobject *kobj,
1118                                         struct kobj_attribute *attr,
1119                                         char *buf)
1120 {
1121         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1122 }
1123
1124 static ssize_t fadump_register_show(struct kobject *kobj,
1125                                         struct kobj_attribute *attr,
1126                                         char *buf)
1127 {
1128         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1129 }
1130
1131 static ssize_t fadump_register_store(struct kobject *kobj,
1132                                         struct kobj_attribute *attr,
1133                                         const char *buf, size_t count)
1134 {
1135         int ret = 0;
1136
1137         if (!fw_dump.fadump_enabled || fdm_active)
1138                 return -EPERM;
1139
1140         mutex_lock(&fadump_mutex);
1141
1142         switch (buf[0]) {
1143         case '0':
1144                 if (fw_dump.dump_registered == 0) {
1145                         ret = -EINVAL;
1146                         goto unlock_out;
1147                 }
1148                 /* Un-register Firmware-assisted dump */
1149                 fadump_unregister_dump(&fdm);
1150                 break;
1151         case '1':
1152                 if (fw_dump.dump_registered == 1) {
1153                         ret = -EINVAL;
1154                         goto unlock_out;
1155                 }
1156                 /* Register Firmware-assisted dump */
1157                 register_fadump();
1158                 break;
1159         default:
1160                 ret = -EINVAL;
1161                 break;
1162         }
1163
1164 unlock_out:
1165         mutex_unlock(&fadump_mutex);
1166         return ret < 0 ? ret : count;
1167 }
1168
1169 static int fadump_region_show(struct seq_file *m, void *private)
1170 {
1171         const struct fadump_mem_struct *fdm_ptr;
1172
1173         if (!fw_dump.fadump_enabled)
1174                 return 0;
1175
1176         mutex_lock(&fadump_mutex);
1177         if (fdm_active)
1178                 fdm_ptr = fdm_active;
1179         else {
1180                 mutex_unlock(&fadump_mutex);
1181                 fdm_ptr = &fdm;
1182         }
1183
1184         seq_printf(m,
1185                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1186                         "Dumped: %#llx\n",
1187                         fdm_ptr->cpu_state_data.destination_address,
1188                         fdm_ptr->cpu_state_data.destination_address +
1189                         fdm_ptr->cpu_state_data.source_len - 1,
1190                         fdm_ptr->cpu_state_data.source_len,
1191                         fdm_ptr->cpu_state_data.bytes_dumped);
1192         seq_printf(m,
1193                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1194                         "Dumped: %#llx\n",
1195                         fdm_ptr->hpte_region.destination_address,
1196                         fdm_ptr->hpte_region.destination_address +
1197                         fdm_ptr->hpte_region.source_len - 1,
1198                         fdm_ptr->hpte_region.source_len,
1199                         fdm_ptr->hpte_region.bytes_dumped);
1200         seq_printf(m,
1201                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1202                         "Dumped: %#llx\n",
1203                         fdm_ptr->rmr_region.destination_address,
1204                         fdm_ptr->rmr_region.destination_address +
1205                         fdm_ptr->rmr_region.source_len - 1,
1206                         fdm_ptr->rmr_region.source_len,
1207                         fdm_ptr->rmr_region.bytes_dumped);
1208
1209         if (!fdm_active ||
1210                 (fw_dump.reserve_dump_area_start ==
1211                 fdm_ptr->cpu_state_data.destination_address))
1212                 goto out;
1213
1214         /* Dump is active. Show reserved memory region. */
1215         seq_printf(m,
1216                         "    : [%#016llx-%#016llx] %#llx bytes, "
1217                         "Dumped: %#llx\n",
1218                         (unsigned long long)fw_dump.reserve_dump_area_start,
1219                         fdm_ptr->cpu_state_data.destination_address - 1,
1220                         fdm_ptr->cpu_state_data.destination_address -
1221                         fw_dump.reserve_dump_area_start,
1222                         fdm_ptr->cpu_state_data.destination_address -
1223                         fw_dump.reserve_dump_area_start);
1224 out:
1225         if (fdm_active)
1226                 mutex_unlock(&fadump_mutex);
1227         return 0;
1228 }
1229
1230 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1231                                                 0200, NULL,
1232                                                 fadump_release_memory_store);
1233 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1234                                                 0444, fadump_enabled_show,
1235                                                 NULL);
1236 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1237                                                 0644, fadump_register_show,
1238                                                 fadump_register_store);
1239
1240 static int fadump_region_open(struct inode *inode, struct file *file)
1241 {
1242         return single_open(file, fadump_region_show, inode->i_private);
1243 }
1244
1245 static const struct file_operations fadump_region_fops = {
1246         .open    = fadump_region_open,
1247         .read    = seq_read,
1248         .llseek  = seq_lseek,
1249         .release = single_release,
1250 };
1251
1252 static void fadump_init_files(void)
1253 {
1254         struct dentry *debugfs_file;
1255         int rc = 0;
1256
1257         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1258         if (rc)
1259                 printk(KERN_ERR "fadump: unable to create sysfs file"
1260                         " fadump_enabled (%d)\n", rc);
1261
1262         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1263         if (rc)
1264                 printk(KERN_ERR "fadump: unable to create sysfs file"
1265                         " fadump_registered (%d)\n", rc);
1266
1267         debugfs_file = debugfs_create_file("fadump_region", 0444,
1268                                         powerpc_debugfs_root, NULL,
1269                                         &fadump_region_fops);
1270         if (!debugfs_file)
1271                 printk(KERN_ERR "fadump: unable to create debugfs file"
1272                                 " fadump_region\n");
1273
1274         if (fw_dump.dump_active) {
1275                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1276                 if (rc)
1277                         printk(KERN_ERR "fadump: unable to create sysfs file"
1278                                 " fadump_release_mem (%d)\n", rc);
1279         }
1280         return;
1281 }
1282
1283 /*
1284  * Prepare for firmware-assisted dump.
1285  */
1286 int __init setup_fadump(void)
1287 {
1288         if (!fw_dump.fadump_enabled)
1289                 return 0;
1290
1291         if (!fw_dump.fadump_supported) {
1292                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1293                         " this hardware\n");
1294                 return 0;
1295         }
1296
1297         fadump_show_config();
1298         /*
1299          * If dump data is available then see if it is valid and prepare for
1300          * saving it to the disk.
1301          */
1302         if (fw_dump.dump_active) {
1303                 /*
1304                  * if dump process fails then invalidate the registration
1305                  * and release memory before proceeding for re-registration.
1306                  */
1307                 if (process_fadump(fdm_active) < 0)
1308                         fadump_invalidate_release_mem();
1309         }
1310         /* Initialize the kernel dump memory structure for FAD registration. */
1311         else if (fw_dump.reserve_dump_area_size)
1312                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1313         fadump_init_files();
1314
1315         return 1;
1316 }
1317 subsys_initcall(setup_fadump);