arch/powerpc/kernel/fadump.c

   1 /*
   2  * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
   3  * dump with assistance from firmware. This approach does not use kexec,
   4  * instead firmware assists in booting the kdump kernel while preserving
   5  * memory contents. The most of the code implementation has been adapted
   6  * from phyp assisted dump implementation written by Linas Vepstas and
   7  * Manish Ahuja
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  *
  23  * Copyright 2011 IBM Corporation
  24  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
  25  */
  26
  27 #undef DEBUG
  28 #define pr_fmt(fmt) "fadump: " fmt
  29
  30 #include <linux/string.h>
  31 #include <linux/memblock.h>
  32 #include <linux/delay.h>
  33 #include <linux/debugfs.h>
  34 #include <linux/seq_file.h>
  35 #include <linux/crash_dump.h>
  36 #include <linux/kobject.h>
  37 #include <linux/sysfs.h>
  38
  39 #include <asm/page.h>
  40 #include <asm/prom.h>
  41 #include <asm/rtas.h>
  42 #include <asm/fadump.h>
  43 #include <asm/debug.h>
  44 #include <asm/setup.h>
  45
  46 static struct fw_dump fw_dump;
  47 static struct fadump_mem_struct fdm;
  48 static const struct fadump_mem_struct *fdm_active;
  49
  50 static DEFINE_MUTEX(fadump_mutex);
  51 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
  52 int crash_mem_ranges;
  53
  54 /* Scan the Firmware Assisted dump configuration details. */
  55 int __init early_init_dt_scan_fw_dump(unsigned long node,
  56                         const char *uname, int depth, void *data)
  57 {
  58         const __be32 *sections;
  59         int i, num_sections;
  60         int size;
  61         const __be32 *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 1;
  73
  74         fw_dump.fadump_supported = 1;
  75         fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*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 1;
  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
 114         return 1;
 115 }
 116
 117 int is_fadump_active(void)
 118 {
 119         return fw_dump.dump_active;
 120 }
 121
 122 /* Print firmware assisted dump configurations for debugging purpose. */
 123 static void fadump_show_config(void)
 124 {
 125         pr_debug("Support for firmware-assisted dump (fadump): %s\n",
 126                         (fw_dump.fadump_supported ? "present" : "no support"));
 127
 128         if (!fw_dump.fadump_supported)
 129                 return;
 130
 131         pr_debug("Fadump enabled    : %s\n",
 132                                 (fw_dump.fadump_enabled ? "yes" : "no"));
 133         pr_debug("Dump Active       : %s\n",
 134                                 (fw_dump.dump_active ? "yes" : "no"));
 135         pr_debug("Dump section sizes:\n");
 136         pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
 137         pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
 138         pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
 139 }
 140
 141 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
 142                                 unsigned long addr)
 143 {
 144         if (!fdm)
 145                 return 0;
 146
 147         memset(fdm, 0, sizeof(struct fadump_mem_struct));
 148         addr = addr & PAGE_MASK;
 149
 150         fdm->header.dump_format_version = cpu_to_be32(0x00000001);
 151         fdm->header.dump_num_sections = cpu_to_be16(3);
 152         fdm->header.dump_status_flag = 0;
 153         fdm->header.offset_first_dump_section =
 154                 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
 155
 156         /*
 157          * Fields for disk dump option.
 158          * We are not using disk dump option, hence set these fields to 0.
 159          */
 160         fdm->header.dd_block_size = 0;
 161         fdm->header.dd_block_offset = 0;
 162         fdm->header.dd_num_blocks = 0;
 163         fdm->header.dd_offset_disk_path = 0;
 164
 165         /* set 0 to disable an automatic dump-reboot. */
 166         fdm->header.max_time_auto = 0;
 167
 168         /* Kernel dump sections */
 169         /* cpu state data section. */
 170         fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 171         fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
 172         fdm->cpu_state_data.source_address = 0;
 173         fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
 174         fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
 175         addr += fw_dump.cpu_state_data_size;
 176
 177         /* hpte region section */
 178         fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 179         fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
 180         fdm->hpte_region.source_address = 0;
 181         fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
 182         fdm->hpte_region.destination_address = cpu_to_be64(addr);
 183         addr += fw_dump.hpte_region_size;
 184
 185         /* RMA region section */
 186         fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 187         fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
 188         fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
 189         fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
 190         fdm->rmr_region.destination_address = cpu_to_be64(addr);
 191         addr += fw_dump.boot_memory_size;
 192
 193         return addr;
 194 }
 195
 196 /**
 197  * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
 198  *
 199  * Function to find the largest memory size we need to reserve during early
 200  * boot process. This will be the size of the memory that is required for a
 201  * kernel to boot successfully.
 202  *
 203  * This function has been taken from phyp-assisted dump feature implementation.
 204  *
 205  * returns larger of 256MB or 5% rounded down to multiples of 256MB.
 206  *
 207  * TODO: Come up with better approach to find out more accurate memory size
 208  * that is required for a kernel to boot successfully.
 209  *
 210  */
 211 static inline unsigned long fadump_calculate_reserve_size(void)
 212 {
 213         unsigned long size;
 214
 215         /*
 216          * Check if the size is specified through fadump_reserve_mem= cmdline
 217          * option. If yes, then use that.
 218          */
 219         if (fw_dump.reserve_bootvar)
 220                 return fw_dump.reserve_bootvar;
 221
 222         /* divide by 20 to get 5% of value */
 223         size = memblock_end_of_DRAM() / 20;
 224
 225         /* round it down in multiples of 256 */
 226         size = size & ~0x0FFFFFFFUL;
 227
 228         /* Truncate to memory_limit. We don't want to over reserve the memory.*/
 229         if (memory_limit && size > memory_limit)
 230                 size = memory_limit;
 231
 232         return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
 233 }
 234
 235 /*
 236  * Calculate the total memory size required to be reserved for
 237  * firmware-assisted dump registration.
 238  */
 239 static unsigned long get_fadump_area_size(void)
 240 {
 241         unsigned long size = 0;
 242
 243         size += fw_dump.cpu_state_data_size;
 244         size += fw_dump.hpte_region_size;
 245         size += fw_dump.boot_memory_size;
 246         size += sizeof(struct fadump_crash_info_header);
 247         size += sizeof(struct elfhdr); /* ELF core header.*/
 248         size += sizeof(struct elf_phdr); /* place holder for cpu notes */
 249         /* Program headers for crash memory regions. */
 250         size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
 251
 252         size = PAGE_ALIGN(size);
 253         return size;
 254 }
 255
 256 int __init fadump_reserve_mem(void)
 257 {
 258         unsigned long base, size, memory_boundary;
 259
 260         if (!fw_dump.fadump_enabled)
 261                 return 0;
 262
 263         if (!fw_dump.fadump_supported) {
 264                 printk(KERN_INFO "Firmware-assisted dump is not supported on"
 265                                 " this hardware\n");
 266                 fw_dump.fadump_enabled = 0;
 267                 return 0;
 268         }
 269         /*
 270          * Initialize boot memory size
 271          * If dump is active then we have already calculated the size during
 272          * first kernel.
 273          */
 274         if (fdm_active)
 275                 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
 276         else
 277                 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
 278
 279         /*
 280          * Calculate the memory boundary.
 281          * If memory_limit is less than actual memory boundary then reserve
 282          * the memory for fadump beyond the memory_limit and adjust the
 283          * memory_limit accordingly, so that the running kernel can run with
 284          * specified memory_limit.
 285          */
 286         if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
 287                 size = get_fadump_area_size();
 288                 if ((memory_limit + size) < memblock_end_of_DRAM())
 289                         memory_limit += size;
 290                 else
 291                         memory_limit = memblock_end_of_DRAM();
 292                 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
 293                                 " dump, now %#016llx\n", 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                                 be64_to_cpu(fdm_active->rmr_region.destination_address) +
 318                                 be64_to_cpu(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->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 (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
 476                 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
 477                                         be64_to_cpu(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 = be64_to_cpu(fdm->cpu_state_data.destination_address);
 607         vaddr = __va(addr);
 608
 609         reg_header = vaddr;
 610         if (be64_to_cpu(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", be64_to_cpu(reg_header->magic_number));
 616         pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
 617
 618         vaddr += be32_to_cpu(reg_header->num_cpu_offset);
 619         num_cpus = be32_to_cpu(*((__be32 *)(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 (be64_to_cpu(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 = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
 649                 if (fdh && !cpumask_test_cpu(cpu, &fdh->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         if (fdh) {
 667                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 668                                                         fdh->elfcorehdr_addr);
 669                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 670         }
 671         return 0;
 672
 673 error_out:
 674         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 675                                         fw_dump.cpu_notes_buf_size);
 676         fw_dump.cpu_notes_buf = 0;
 677         fw_dump.cpu_notes_buf_size = 0;
 678         return rc;
 679
 680 }
 681
 682 /*
 683  * Validate and process the dump data stored by firmware before exporting
 684  * it through '/proc/vmcore'.
 685  */
 686 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 687 {
 688         struct fadump_crash_info_header *fdh;
 689         int rc = 0;
 690
 691         if (!fdm_active || !fw_dump.fadumphdr_addr)
 692                 return -EINVAL;
 693
 694         /* Check if the dump data is valid. */
 695         if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
 696                         (fdm_active->cpu_state_data.error_flags != 0) ||
 697                         (fdm_active->rmr_region.error_flags != 0)) {
 698                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 699                 return -EINVAL;
 700         }
 701         if ((fdm_active->rmr_region.bytes_dumped !=
 702                         fdm_active->rmr_region.source_len) ||
 703                         !fdm_active->cpu_state_data.bytes_dumped) {
 704                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 705                 return -EINVAL;
 706         }
 707
 708         /* Validate the fadump crash info header */
 709         fdh = __va(fw_dump.fadumphdr_addr);
 710         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 711                 printk(KERN_ERR "Crash info header is not valid.\n");
 712                 return -EINVAL;
 713         }
 714
 715         rc = fadump_build_cpu_notes(fdm_active);
 716         if (rc)
 717                 return rc;
 718
 719         /*
 720          * We are done validating dump info and elfcore header is now ready
 721          * to be exported. set elfcorehdr_addr so that vmcore module will
 722          * export the elfcore header through '/proc/vmcore'.
 723          */
 724         elfcorehdr_addr = fdh->elfcorehdr_addr;
 725
 726         return 0;
 727 }
 728
 729 static inline void fadump_add_crash_memory(unsigned long long base,
 730                                         unsigned long long end)
 731 {
 732         if (base == end)
 733                 return;
 734
 735         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 736                 crash_mem_ranges, base, end - 1, (end - base));
 737         crash_memory_ranges[crash_mem_ranges].base = base;
 738         crash_memory_ranges[crash_mem_ranges].size = end - base;
 739         crash_mem_ranges++;
 740 }
 741
 742 static void fadump_exclude_reserved_area(unsigned long long start,
 743                                         unsigned long long end)
 744 {
 745         unsigned long long ra_start, ra_end;
 746
 747         ra_start = fw_dump.reserve_dump_area_start;
 748         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 749
 750         if ((ra_start < end) && (ra_end > start)) {
 751                 if ((start < ra_start) && (end > ra_end)) {
 752                         fadump_add_crash_memory(start, ra_start);
 753                         fadump_add_crash_memory(ra_end, end);
 754                 } else if (start < ra_start) {
 755                         fadump_add_crash_memory(start, ra_start);
 756                 } else if (ra_end < end) {
 757                         fadump_add_crash_memory(ra_end, end);
 758                 }
 759         } else
 760                 fadump_add_crash_memory(start, end);
 761 }
 762
 763 static int fadump_init_elfcore_header(char *bufp)
 764 {
 765         struct elfhdr *elf;
 766
 767         elf = (struct elfhdr *) bufp;
 768         bufp += sizeof(struct elfhdr);
 769         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 770         elf->e_ident[EI_CLASS] = ELF_CLASS;
 771         elf->e_ident[EI_DATA] = ELF_DATA;
 772         elf->e_ident[EI_VERSION] = EV_CURRENT;
 773         elf->e_ident[EI_OSABI] = ELF_OSABI;
 774         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 775         elf->e_type = ET_CORE;
 776         elf->e_machine = ELF_ARCH;
 777         elf->e_version = EV_CURRENT;
 778         elf->e_entry = 0;
 779         elf->e_phoff = sizeof(struct elfhdr);
 780         elf->e_shoff = 0;
 781 #if defined(_CALL_ELF)
 782         elf->e_flags = _CALL_ELF;
 783 #else
 784         elf->e_flags = 0;
 785 #endif
 786         elf->e_ehsize = sizeof(struct elfhdr);
 787         elf->e_phentsize = sizeof(struct elf_phdr);
 788         elf->e_phnum = 0;
 789         elf->e_shentsize = 0;
 790         elf->e_shnum = 0;
 791         elf->e_shstrndx = 0;
 792
 793         return 0;
 794 }
 795
 796 /*
 797  * Traverse through memblock structure and setup crash memory ranges. These
 798  * ranges will be used create PT_LOAD program headers in elfcore header.
 799  */
 800 static void fadump_setup_crash_memory_ranges(void)
 801 {
 802         struct memblock_region *reg;
 803         unsigned long long start, end;
 804
 805         pr_debug("Setup crash memory ranges.\n");
 806         crash_mem_ranges = 0;
 807         /*
 808          * add the first memory chunk (RMA_START through boot_memory_size) as
 809          * a separate memory chunk. The reason is, at the time crash firmware
 810          * will move the content of this memory chunk to different location
 811          * specified during fadump registration. We need to create a separate
 812          * program header for this chunk with the correct offset.
 813          */
 814         fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 815
 816         for_each_memblock(memory, reg) {
 817                 start = (unsigned long long)reg->base;
 818                 end = start + (unsigned long long)reg->size;
 819                 if (start == RMA_START && end >= fw_dump.boot_memory_size)
 820                         start = fw_dump.boot_memory_size;
 821
 822                 /* add this range excluding the reserved dump area. */
 823                 fadump_exclude_reserved_area(start, end);
 824         }
 825 }
 826
 827 /*
 828  * If the given physical address falls within the boot memory region then
 829  * return the relocated address that points to the dump region reserved
 830  * for saving initial boot memory contents.
 831  */
 832 static inline unsigned long fadump_relocate(unsigned long paddr)
 833 {
 834         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 835                 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
 836         else
 837                 return paddr;
 838 }
 839
 840 static int fadump_create_elfcore_headers(char *bufp)
 841 {
 842         struct elfhdr *elf;
 843         struct elf_phdr *phdr;
 844         int i;
 845
 846         fadump_init_elfcore_header(bufp);
 847         elf = (struct elfhdr *)bufp;
 848         bufp += sizeof(struct elfhdr);
 849
 850         /*
 851          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
 852          * will be populated during second kernel boot after crash. Hence
 853          * this PT_NOTE will always be the first elf note.
 854          *
 855          * NOTE: Any new ELF note addition should be placed after this note.
 856          */
 857         phdr = (struct elf_phdr *)bufp;
 858         bufp += sizeof(struct elf_phdr);
 859         phdr->p_type = PT_NOTE;
 860         phdr->p_flags = 0;
 861         phdr->p_vaddr = 0;
 862         phdr->p_align = 0;
 863
 864         phdr->p_offset = 0;
 865         phdr->p_paddr = 0;
 866         phdr->p_filesz = 0;
 867         phdr->p_memsz = 0;
 868
 869         (elf->e_phnum)++;
 870
 871         /* setup ELF PT_NOTE for vmcoreinfo */
 872         phdr = (struct elf_phdr *)bufp;
 873         bufp += sizeof(struct elf_phdr);
 874         phdr->p_type    = PT_NOTE;
 875         phdr->p_flags   = 0;
 876         phdr->p_vaddr   = 0;
 877         phdr->p_align   = 0;
 878
 879         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
 880         phdr->p_offset  = phdr->p_paddr;
 881         phdr->p_memsz   = vmcoreinfo_max_size;
 882         phdr->p_filesz  = vmcoreinfo_max_size;
 883
 884         /* Increment number of program headers. */
 885         (elf->e_phnum)++;
 886
 887         /* setup PT_LOAD sections. */
 888
 889         for (i = 0; i < crash_mem_ranges; i++) {
 890                 unsigned long long mbase, msize;
 891                 mbase = crash_memory_ranges[i].base;
 892                 msize = crash_memory_ranges[i].size;
 893
 894                 if (!msize)
 895                         continue;
 896
 897                 phdr = (struct elf_phdr *)bufp;
 898                 bufp += sizeof(struct elf_phdr);
 899                 phdr->p_type    = PT_LOAD;
 900                 phdr->p_flags   = PF_R|PF_W|PF_X;
 901                 phdr->p_offset  = mbase;
 902
 903                 if (mbase == RMA_START) {
 904                         /*
 905                          * The entire RMA region will be moved by firmware
 906                          * to the specified destination_address. Hence set
 907                          * the correct offset.
 908                          */
 909                         phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
 910                 }
 911
 912                 phdr->p_paddr = mbase;
 913                 phdr->p_vaddr = (unsigned long)__va(mbase);
 914                 phdr->p_filesz = msize;
 915                 phdr->p_memsz = msize;
 916                 phdr->p_align = 0;
 917
 918                 /* Increment number of program headers. */
 919                 (elf->e_phnum)++;
 920         }
 921         return 0;
 922 }
 923
 924 static unsigned long init_fadump_header(unsigned long addr)
 925 {
 926         struct fadump_crash_info_header *fdh;
 927
 928         if (!addr)
 929                 return 0;
 930
 931         fw_dump.fadumphdr_addr = addr;
 932         fdh = __va(addr);
 933         addr += sizeof(struct fadump_crash_info_header);
 934
 935         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
 936         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
 937         fdh->elfcorehdr_addr = addr;
 938         /* We will set the crashing cpu id in crash_fadump() during crash. */
 939         fdh->crashing_cpu = CPU_UNKNOWN;
 940
 941         return addr;
 942 }
 943
 944 static void register_fadump(void)
 945 {
 946         unsigned long addr;
 947         void *vaddr;
 948
 949         /*
 950          * If no memory is reserved then we can not register for firmware-
 951          * assisted dump.
 952          */
 953         if (!fw_dump.reserve_dump_area_size)
 954                 return;
 955
 956         fadump_setup_crash_memory_ranges();
 957
 958         addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
 959         /* Initialize fadump crash info header. */
 960         addr = init_fadump_header(addr);
 961         vaddr = __va(addr);
 962
 963         pr_debug("Creating ELF core headers at %#016lx\n", addr);
 964         fadump_create_elfcore_headers(vaddr);
 965
 966         /* register the future kernel dump with firmware. */
 967         register_fw_dump(&fdm);
 968 }
 969
 970 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
 971 {
 972         int rc = 0;
 973         unsigned int wait_time;
 974
 975         pr_debug("Un-register firmware-assisted dump\n");
 976
 977         /* TODO: Add upper time limit for the delay */
 978         do {
 979                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 980                         FADUMP_UNREGISTER, fdm,
 981                         sizeof(struct fadump_mem_struct));
 982
 983                 wait_time = rtas_busy_delay_time(rc);
 984                 if (wait_time)
 985                         mdelay(wait_time);
 986         } while (wait_time);
 987
 988         if (rc) {
 989                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
 990                         " unexpected error(%d).\n", rc);
 991                 return rc;
 992         }
 993         fw_dump.dump_registered = 0;
 994         return 0;
 995 }
 996
 997 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
 998 {
 999         int rc = 0;
1000         unsigned int wait_time;
1001
1002         pr_debug("Invalidating firmware-assisted dump registration\n");
1003
1004         /* TODO: Add upper time limit for the delay */
1005         do {
1006                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1007                         FADUMP_INVALIDATE, fdm,
1008                         sizeof(struct fadump_mem_struct));
1009
1010                 wait_time = rtas_busy_delay_time(rc);
1011                 if (wait_time)
1012                         mdelay(wait_time);
1013         } while (wait_time);
1014
1015         if (rc) {
1016                 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1017                 return rc;
1018         }
1019         fw_dump.dump_active = 0;
1020         fdm_active = NULL;
1021         return 0;
1022 }
1023
1024 void fadump_cleanup(void)
1025 {
1026         /* Invalidate the registration only if dump is active. */
1027         if (fw_dump.dump_active) {
1028                 init_fadump_mem_struct(&fdm,
1029                         be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1030                 fadump_invalidate_dump(&fdm);
1031         }
1032 }
1033
1034 /*
1035  * Release the memory that was reserved in early boot to preserve the memory
1036  * contents. The released memory will be available for general use.
1037  */
1038 static void fadump_release_memory(unsigned long begin, unsigned long end)
1039 {
1040         unsigned long addr;
1041         unsigned long ra_start, ra_end;
1042
1043         ra_start = fw_dump.reserve_dump_area_start;
1044         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1045
1046         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1047                 /*
1048                  * exclude the dump reserve area. Will reuse it for next
1049                  * fadump registration.
1050                  */
1051                 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1052                         continue;
1053
1054                 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1055         }
1056 }
1057
1058 static void fadump_invalidate_release_mem(void)
1059 {
1060         unsigned long reserved_area_start, reserved_area_end;
1061         unsigned long destination_address;
1062
1063         mutex_lock(&fadump_mutex);
1064         if (!fw_dump.dump_active) {
1065                 mutex_unlock(&fadump_mutex);
1066                 return;
1067         }
1068
1069         destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1070         fadump_cleanup();
1071         mutex_unlock(&fadump_mutex);
1072
1073         /*
1074          * Save the current reserved memory bounds we will require them
1075          * later for releasing the memory for general use.
1076          */
1077         reserved_area_start = fw_dump.reserve_dump_area_start;
1078         reserved_area_end = reserved_area_start +
1079                         fw_dump.reserve_dump_area_size;
1080         /*
1081          * Setup reserve_dump_area_start and its size so that we can
1082          * reuse this reserved memory for Re-registration.
1083          */
1084         fw_dump.reserve_dump_area_start = destination_address;
1085         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1086
1087         fadump_release_memory(reserved_area_start, reserved_area_end);
1088         if (fw_dump.cpu_notes_buf) {
1089                 fadump_cpu_notes_buf_free(
1090                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1091                                 fw_dump.cpu_notes_buf_size);
1092                 fw_dump.cpu_notes_buf = 0;
1093                 fw_dump.cpu_notes_buf_size = 0;
1094         }
1095         /* Initialize the kernel dump memory structure for FAD registration. */
1096         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1097 }
1098
1099 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1100                                         struct kobj_attribute *attr,
1101                                         const char *buf, size_t count)
1102 {
1103         if (!fw_dump.dump_active)
1104                 return -EPERM;
1105
1106         if (buf[0] == '1') {
1107                 /*
1108                  * Take away the '/proc/vmcore'. We are releasing the dump
1109                  * memory, hence it will not be valid anymore.
1110                  */
1111 #ifdef CONFIG_PROC_VMCORE
1112                 vmcore_cleanup();
1113 #endif
1114                 fadump_invalidate_release_mem();
1115
1116         } else
1117                 return -EINVAL;
1118         return count;
1119 }
1120
1121 static ssize_t fadump_enabled_show(struct kobject *kobj,
1122                                         struct kobj_attribute *attr,
1123                                         char *buf)
1124 {
1125         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1126 }
1127
1128 static ssize_t fadump_register_show(struct kobject *kobj,
1129                                         struct kobj_attribute *attr,
1130                                         char *buf)
1131 {
1132         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1133 }
1134
1135 static ssize_t fadump_register_store(struct kobject *kobj,
1136                                         struct kobj_attribute *attr,
1137                                         const char *buf, size_t count)
1138 {
1139         int ret = 0;
1140
1141         if (!fw_dump.fadump_enabled || fdm_active)
1142                 return -EPERM;
1143
1144         mutex_lock(&fadump_mutex);
1145
1146         switch (buf[0]) {
1147         case '0':
1148                 if (fw_dump.dump_registered == 0) {
1149                         ret = -EINVAL;
1150                         goto unlock_out;
1151                 }
1152                 /* Un-register Firmware-assisted dump */
1153                 fadump_unregister_dump(&fdm);
1154                 break;
1155         case '1':
1156                 if (fw_dump.dump_registered == 1) {
1157                         ret = -EINVAL;
1158                         goto unlock_out;
1159                 }
1160                 /* Register Firmware-assisted dump */
1161                 register_fadump();
1162                 break;
1163         default:
1164                 ret = -EINVAL;
1165                 break;
1166         }
1167
1168 unlock_out:
1169         mutex_unlock(&fadump_mutex);
1170         return ret < 0 ? ret : count;
1171 }
1172
1173 static int fadump_region_show(struct seq_file *m, void *private)
1174 {
1175         const struct fadump_mem_struct *fdm_ptr;
1176
1177         if (!fw_dump.fadump_enabled)
1178                 return 0;
1179
1180         mutex_lock(&fadump_mutex);
1181         if (fdm_active)
1182                 fdm_ptr = fdm_active;
1183         else {
1184                 mutex_unlock(&fadump_mutex);
1185                 fdm_ptr = &fdm;
1186         }
1187
1188         seq_printf(m,
1189                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1190                         "Dumped: %#llx\n",
1191                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1192                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1193                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1194                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1195                         be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1196         seq_printf(m,
1197                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1198                         "Dumped: %#llx\n",
1199                         be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1200                         be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1201                         be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1202                         be64_to_cpu(fdm_ptr->hpte_region.source_len),
1203                         be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1204         seq_printf(m,
1205                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1206                         "Dumped: %#llx\n",
1207                         be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1208                         be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1209                         be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1210                         be64_to_cpu(fdm_ptr->rmr_region.source_len),
1211                         be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1212
1213         if (!fdm_active ||
1214                 (fw_dump.reserve_dump_area_start ==
1215                 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1216                 goto out;
1217
1218         /* Dump is active. Show reserved memory region. */
1219         seq_printf(m,
1220                         "    : [%#016llx-%#016llx] %#llx bytes, "
1221                         "Dumped: %#llx\n",
1222                         (unsigned long long)fw_dump.reserve_dump_area_start,
1223                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1224                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1225                         fw_dump.reserve_dump_area_start,
1226                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1227                         fw_dump.reserve_dump_area_start);
1228 out:
1229         if (fdm_active)
1230                 mutex_unlock(&fadump_mutex);
1231         return 0;
1232 }
1233
1234 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1235                                                 0200, NULL,
1236                                                 fadump_release_memory_store);
1237 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1238                                                 0444, fadump_enabled_show,
1239                                                 NULL);
1240 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1241                                                 0644, fadump_register_show,
1242                                                 fadump_register_store);
1243
1244 static int fadump_region_open(struct inode *inode, struct file *file)
1245 {
1246         return single_open(file, fadump_region_show, inode->i_private);
1247 }
1248
1249 static const struct file_operations fadump_region_fops = {
1250         .open    = fadump_region_open,
1251         .read    = seq_read,
1252         .llseek  = seq_lseek,
1253         .release = single_release,
1254 };
1255
1256 static void fadump_init_files(void)
1257 {
1258         struct dentry *debugfs_file;
1259         int rc = 0;
1260
1261         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1262         if (rc)
1263                 printk(KERN_ERR "fadump: unable to create sysfs file"
1264                         " fadump_enabled (%d)\n", rc);
1265
1266         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1267         if (rc)
1268                 printk(KERN_ERR "fadump: unable to create sysfs file"
1269                         " fadump_registered (%d)\n", rc);
1270
1271         debugfs_file = debugfs_create_file("fadump_region", 0444,
1272                                         powerpc_debugfs_root, NULL,
1273                                         &fadump_region_fops);
1274         if (!debugfs_file)
1275                 printk(KERN_ERR "fadump: unable to create debugfs file"
1276                                 " fadump_region\n");
1277
1278         if (fw_dump.dump_active) {
1279                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1280                 if (rc)
1281                         printk(KERN_ERR "fadump: unable to create sysfs file"
1282                                 " fadump_release_mem (%d)\n", rc);
1283         }
1284         return;
1285 }
1286
1287 /*
1288  * Prepare for firmware-assisted dump.
1289  */
1290 int __init setup_fadump(void)
1291 {
1292         if (!fw_dump.fadump_enabled)
1293                 return 0;
1294
1295         if (!fw_dump.fadump_supported) {
1296                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1297                         " this hardware\n");
1298                 return 0;
1299         }
1300
1301         fadump_show_config();
1302         /*
1303          * If dump data is available then see if it is valid and prepare for
1304          * saving it to the disk.
1305          */
1306         if (fw_dump.dump_active) {
1307                 /*
1308                  * if dump process fails then invalidate the registration
1309                  * and release memory before proceeding for re-registration.
1310                  */
1311                 if (process_fadump(fdm_active) < 0)
1312                         fadump_invalidate_release_mem();
1313         }
1314         /* Initialize the kernel dump memory structure for FAD registration. */
1315         else if (fw_dump.reserve_dump_area_size)
1316                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1317         fadump_init_files();
1318
1319         return 1;
1320 }
1321 subsys_initcall(setup_fadump);