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