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/seq_file.h>
  34 #include <linux/crash_dump.h>
  35 #include <linux/kobject.h>
  36 #include <linux/sysfs.h>
  37
  38 #include <asm/debugfs.h>
  39 #include <asm/page.h>
  40 #include <asm/prom.h>
  41 #include <asm/rtas.h>
  42 #include <asm/fadump.h>
  43 #include <asm/setup.h>
  44
  45 static struct fw_dump fw_dump;
  46 static struct fadump_mem_struct fdm;
  47 static const struct fadump_mem_struct *fdm_active;
  48
  49 static DEFINE_MUTEX(fadump_mutex);
  50 struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
  51 int crash_mem_ranges;
  52
  53 /* Scan the Firmware Assisted dump configuration details. */
  54 int __init early_init_dt_scan_fw_dump(unsigned long node,
  55                         const char *uname, int depth, void *data)
  56 {
  57         const __be32 *sections;
  58         int i, num_sections;
  59         int size;
  60         const __be32 *token;
  61
  62         if (depth != 1 || strcmp(uname, "rtas") != 0)
  63                 return 0;
  64
  65         /*
  66          * Check if Firmware Assisted dump is supported. if yes, check
  67          * if dump has been initiated on last reboot.
  68          */
  69         token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
  70         if (!token)
  71                 return 1;
  72
  73         fw_dump.fadump_supported = 1;
  74         fw_dump.ibm_configure_kernel_dump = be32_to_cpu(*token);
  75
  76         /*
  77          * The 'ibm,kernel-dump' rtas node is present only if there is
  78          * dump data waiting for us.
  79          */
  80         fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
  81         if (fdm_active)
  82                 fw_dump.dump_active = 1;
  83
  84         /* Get the sizes required to store dump data for the firmware provided
  85          * dump sections.
  86          * For each dump section type supported, a 32bit cell which defines
  87          * the ID of a supported section followed by two 32 bit cells which
  88          * gives teh size of the section in bytes.
  89          */
  90         sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
  91                                         &size);
  92
  93         if (!sections)
  94                 return 1;
  95
  96         num_sections = size / (3 * sizeof(u32));
  97
  98         for (i = 0; i < num_sections; i++, sections += 3) {
  99                 u32 type = (u32)of_read_number(sections, 1);
 100
 101                 switch (type) {
 102                 case FADUMP_CPU_STATE_DATA:
 103                         fw_dump.cpu_state_data_size =
 104                                         of_read_ulong(&sections[1], 2);
 105                         break;
 106                 case FADUMP_HPTE_REGION:
 107                         fw_dump.hpte_region_size =
 108                                         of_read_ulong(&sections[1], 2);
 109                         break;
 110                 }
 111         }
 112
 113         return 1;
 114 }
 115
 116 /*
 117  * If fadump is registered, check if the memory provided
 118  * falls within boot memory area.
 119  */
 120 int is_fadump_boot_memory_area(u64 addr, ulong size)
 121 {
 122         if (!fw_dump.dump_registered)
 123                 return 0;
 124
 125         return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size;
 126 }
 127
 128 int should_fadump_crash(void)
 129 {
 130         if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
 131                 return 0;
 132         return 1;
 133 }
 134
 135 int is_fadump_active(void)
 136 {
 137         return fw_dump.dump_active;
 138 }
 139
 140 /*
 141  * Returns 1, if there are no holes in boot memory area,
 142  * 0 otherwise.
 143  */
 144 static int is_boot_memory_area_contiguous(void)
 145 {
 146         struct memblock_region *reg;
 147         unsigned long tstart, tend;
 148         unsigned long start_pfn = PHYS_PFN(RMA_START);
 149         unsigned long end_pfn = PHYS_PFN(RMA_START + fw_dump.boot_memory_size);
 150         unsigned int ret = 0;
 151
 152         for_each_memblock(memory, reg) {
 153                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
 154                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
 155                 if (tstart < tend) {
 156                         /* Memory hole from start_pfn to tstart */
 157                         if (tstart > start_pfn)
 158                                 break;
 159
 160                         if (tend == end_pfn) {
 161                                 ret = 1;
 162                                 break;
 163                         }
 164
 165                         start_pfn = tend + 1;
 166                 }
 167         }
 168
 169         return ret;
 170 }
 171
 172 /* Print firmware assisted dump configurations for debugging purpose. */
 173 static void fadump_show_config(void)
 174 {
 175         pr_debug("Support for firmware-assisted dump (fadump): %s\n",
 176                         (fw_dump.fadump_supported ? "present" : "no support"));
 177
 178         if (!fw_dump.fadump_supported)
 179                 return;
 180
 181         pr_debug("Fadump enabled    : %s\n",
 182                                 (fw_dump.fadump_enabled ? "yes" : "no"));
 183         pr_debug("Dump Active       : %s\n",
 184                                 (fw_dump.dump_active ? "yes" : "no"));
 185         pr_debug("Dump section sizes:\n");
 186         pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
 187         pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
 188         pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
 189 }
 190
 191 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
 192                                 unsigned long addr)
 193 {
 194         if (!fdm)
 195                 return 0;
 196
 197         memset(fdm, 0, sizeof(struct fadump_mem_struct));
 198         addr = addr & PAGE_MASK;
 199
 200         fdm->header.dump_format_version = cpu_to_be32(0x00000001);
 201         fdm->header.dump_num_sections = cpu_to_be16(3);
 202         fdm->header.dump_status_flag = 0;
 203         fdm->header.offset_first_dump_section =
 204                 cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
 205
 206         /*
 207          * Fields for disk dump option.
 208          * We are not using disk dump option, hence set these fields to 0.
 209          */
 210         fdm->header.dd_block_size = 0;
 211         fdm->header.dd_block_offset = 0;
 212         fdm->header.dd_num_blocks = 0;
 213         fdm->header.dd_offset_disk_path = 0;
 214
 215         /* set 0 to disable an automatic dump-reboot. */
 216         fdm->header.max_time_auto = 0;
 217
 218         /* Kernel dump sections */
 219         /* cpu state data section. */
 220         fdm->cpu_state_data.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 221         fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
 222         fdm->cpu_state_data.source_address = 0;
 223         fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
 224         fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
 225         addr += fw_dump.cpu_state_data_size;
 226
 227         /* hpte region section */
 228         fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 229         fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
 230         fdm->hpte_region.source_address = 0;
 231         fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
 232         fdm->hpte_region.destination_address = cpu_to_be64(addr);
 233         addr += fw_dump.hpte_region_size;
 234
 235         /* RMA region section */
 236         fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 237         fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
 238         fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
 239         fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
 240         fdm->rmr_region.destination_address = cpu_to_be64(addr);
 241         addr += fw_dump.boot_memory_size;
 242
 243         return addr;
 244 }
 245
 246 /**
 247  * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
 248  *
 249  * Function to find the largest memory size we need to reserve during early
 250  * boot process. This will be the size of the memory that is required for a
 251  * kernel to boot successfully.
 252  *
 253  * This function has been taken from phyp-assisted dump feature implementation.
 254  *
 255  * returns larger of 256MB or 5% rounded down to multiples of 256MB.
 256  *
 257  * TODO: Come up with better approach to find out more accurate memory size
 258  * that is required for a kernel to boot successfully.
 259  *
 260  */
 261 static inline unsigned long fadump_calculate_reserve_size(void)
 262 {
 263         int ret;
 264         unsigned long long base, size;
 265
 266         if (fw_dump.reserve_bootvar)
 267                 pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n");
 268
 269         /*
 270          * Check if the size is specified through crashkernel= cmdline
 271          * option. If yes, then use that but ignore base as fadump reserves
 272          * memory at a predefined offset.
 273          */
 274         ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 275                                 &size, &base);
 276         if (ret == 0 && size > 0) {
 277                 unsigned long max_size;
 278
 279                 if (fw_dump.reserve_bootvar)
 280                         pr_info("Using 'crashkernel=' parameter for memory reservation.\n");
 281
 282                 fw_dump.reserve_bootvar = (unsigned long)size;
 283
 284                 /*
 285                  * Adjust if the boot memory size specified is above
 286                  * the upper limit.
 287                  */
 288                 max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO;
 289                 if (fw_dump.reserve_bootvar > max_size) {
 290                         fw_dump.reserve_bootvar = max_size;
 291                         pr_info("Adjusted boot memory size to %luMB\n",
 292                                 (fw_dump.reserve_bootvar >> 20));
 293                 }
 294
 295                 return fw_dump.reserve_bootvar;
 296         } else if (fw_dump.reserve_bootvar) {
 297                 /*
 298                  * 'fadump_reserve_mem=' is being used to reserve memory
 299                  * for firmware-assisted dump.
 300                  */
 301                 return fw_dump.reserve_bootvar;
 302         }
 303
 304         /* divide by 20 to get 5% of value */
 305         size = memblock_phys_mem_size() / 20;
 306
 307         /* round it down in multiples of 256 */
 308         size = size & ~0x0FFFFFFFUL;
 309
 310         /* Truncate to memory_limit. We don't want to over reserve the memory.*/
 311         if (memory_limit && size > memory_limit)
 312                 size = memory_limit;
 313
 314         return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
 315 }
 316
 317 /*
 318  * Calculate the total memory size required to be reserved for
 319  * firmware-assisted dump registration.
 320  */
 321 static unsigned long get_fadump_area_size(void)
 322 {
 323         unsigned long size = 0;
 324
 325         size += fw_dump.cpu_state_data_size;
 326         size += fw_dump.hpte_region_size;
 327         size += fw_dump.boot_memory_size;
 328         size += sizeof(struct fadump_crash_info_header);
 329         size += sizeof(struct elfhdr); /* ELF core header.*/
 330         size += sizeof(struct elf_phdr); /* place holder for cpu notes */
 331         /* Program headers for crash memory regions. */
 332         size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
 333
 334         size = PAGE_ALIGN(size);
 335         return size;
 336 }
 337
 338 static void __init fadump_reserve_crash_area(unsigned long base,
 339                                              unsigned long size)
 340 {
 341         struct memblock_region *reg;
 342         unsigned long mstart, mend, msize;
 343
 344         for_each_memblock(memory, reg) {
 345                 mstart = max_t(unsigned long, base, reg->base);
 346                 mend = reg->base + reg->size;
 347                 mend = min(base + size, mend);
 348
 349                 if (mstart < mend) {
 350                         msize = mend - mstart;
 351                         memblock_reserve(mstart, msize);
 352                         pr_info("Reserved %ldMB of memory at %#016lx for saving crash dump\n",
 353                                 (msize >> 20), mstart);
 354                 }
 355         }
 356 }
 357
 358 int __init fadump_reserve_mem(void)
 359 {
 360         unsigned long base, size, memory_boundary;
 361
 362         if (!fw_dump.fadump_enabled)
 363                 return 0;
 364
 365         if (!fw_dump.fadump_supported) {
 366                 printk(KERN_INFO "Firmware-assisted dump is not supported on"
 367                                 " this hardware\n");
 368                 fw_dump.fadump_enabled = 0;
 369                 return 0;
 370         }
 371         /*
 372          * Initialize boot memory size
 373          * If dump is active then we have already calculated the size during
 374          * first kernel.
 375          */
 376         if (fdm_active)
 377                 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
 378         else
 379                 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
 380
 381         /*
 382          * Calculate the memory boundary.
 383          * If memory_limit is less than actual memory boundary then reserve
 384          * the memory for fadump beyond the memory_limit and adjust the
 385          * memory_limit accordingly, so that the running kernel can run with
 386          * specified memory_limit.
 387          */
 388         if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
 389                 size = get_fadump_area_size();
 390                 if ((memory_limit + size) < memblock_end_of_DRAM())
 391                         memory_limit += size;
 392                 else
 393                         memory_limit = memblock_end_of_DRAM();
 394                 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
 395                                 " dump, now %#016llx\n", memory_limit);
 396         }
 397         if (memory_limit)
 398                 memory_boundary = memory_limit;
 399         else
 400                 memory_boundary = memblock_end_of_DRAM();
 401
 402         if (fw_dump.dump_active) {
 403                 pr_info("Firmware-assisted dump is active.\n");
 404
 405 #ifdef CONFIG_HUGETLB_PAGE
 406                 /*
 407                  * FADump capture kernel doesn't care much about hugepages.
 408                  * In fact, handling hugepages in capture kernel is asking for
 409                  * trouble. So, disable HugeTLB support when fadump is active.
 410                  */
 411                 hugetlb_disabled = true;
 412 #endif
 413                 /*
 414                  * If last boot has crashed then reserve all the memory
 415                  * above boot_memory_size so that we don't touch it until
 416                  * dump is written to disk by userspace tool. This memory
 417                  * will be released for general use once the dump is saved.
 418                  */
 419                 base = fw_dump.boot_memory_size;
 420                 size = memory_boundary - base;
 421                 fadump_reserve_crash_area(base, size);
 422
 423                 fw_dump.fadumphdr_addr =
 424                                 be64_to_cpu(fdm_active->rmr_region.destination_address) +
 425                                 be64_to_cpu(fdm_active->rmr_region.source_len);
 426                 pr_debug("fadumphdr_addr = %p\n",
 427                                 (void *) fw_dump.fadumphdr_addr);
 428         } else {
 429                 size = get_fadump_area_size();
 430
 431                 /*
 432                  * Reserve memory at an offset closer to bottom of the RAM to
 433                  * minimize the impact of memory hot-remove operation. We can't
 434                  * use memblock_find_in_range() here since it doesn't allocate
 435                  * from bottom to top.
 436                  */
 437                 for (base = fw_dump.boot_memory_size;
 438                      base <= (memory_boundary - size);
 439                      base += size) {
 440                         if (memblock_is_region_memory(base, size) &&
 441                             !memblock_is_region_reserved(base, size))
 442                                 break;
 443                 }
 444                 if ((base > (memory_boundary - size)) ||
 445                     memblock_reserve(base, size)) {
 446                         pr_err("Failed to reserve memory\n");
 447                         return 0;
 448                 }
 449
 450                 pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
 451                         "assisted dump (System RAM: %ldMB)\n",
 452                         (unsigned long)(size >> 20),
 453                         (unsigned long)(base >> 20),
 454                         (unsigned long)(memblock_phys_mem_size() >> 20));
 455         }
 456
 457         fw_dump.reserve_dump_area_start = base;
 458         fw_dump.reserve_dump_area_size = size;
 459         return 1;
 460 }
 461
 462 unsigned long __init arch_reserved_kernel_pages(void)
 463 {
 464         return memblock_reserved_size() / PAGE_SIZE;
 465 }
 466
 467 /* Look for fadump= cmdline option. */
 468 static int __init early_fadump_param(char *p)
 469 {
 470         if (!p)
 471                 return 1;
 472
 473         if (strncmp(p, "on", 2) == 0)
 474                 fw_dump.fadump_enabled = 1;
 475         else if (strncmp(p, "off", 3) == 0)
 476                 fw_dump.fadump_enabled = 0;
 477
 478         return 0;
 479 }
 480 early_param("fadump", early_fadump_param);
 481
 482 /*
 483  * Look for fadump_reserve_mem= cmdline option
 484  * TODO: Remove references to 'fadump_reserve_mem=' parameter,
 485  *       the sooner 'crashkernel=' parameter is accustomed to.
 486  */
 487 static int __init early_fadump_reserve_mem(char *p)
 488 {
 489         if (p)
 490                 fw_dump.reserve_bootvar = memparse(p, &p);
 491         return 0;
 492 }
 493 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
 494
 495 static int register_fw_dump(struct fadump_mem_struct *fdm)
 496 {
 497         int rc, err;
 498         unsigned int wait_time;
 499
 500         pr_debug("Registering for firmware-assisted kernel dump...\n");
 501
 502         /* TODO: Add upper time limit for the delay */
 503         do {
 504                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 505                         FADUMP_REGISTER, fdm,
 506                         sizeof(struct fadump_mem_struct));
 507
 508                 wait_time = rtas_busy_delay_time(rc);
 509                 if (wait_time)
 510                         mdelay(wait_time);
 511
 512         } while (wait_time);
 513
 514         err = -EIO;
 515         switch (rc) {
 516         default:
 517                 pr_err("Failed to register. Unknown Error(%d).\n", rc);
 518                 break;
 519         case -1:
 520                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 521                         " dump. Hardware Error(%d).\n", rc);
 522                 break;
 523         case -3:
 524                 if (!is_boot_memory_area_contiguous())
 525                         pr_err("Can't have holes in boot memory area while "
 526                                "registering fadump\n");
 527
 528                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 529                         " dump. Parameter Error(%d).\n", rc);
 530                 err = -EINVAL;
 531                 break;
 532         case -9:
 533                 printk(KERN_ERR "firmware-assisted kernel dump is already "
 534                         " registered.");
 535                 fw_dump.dump_registered = 1;
 536                 err = -EEXIST;
 537                 break;
 538         case 0:
 539                 printk(KERN_INFO "firmware-assisted kernel dump registration"
 540                         " is successful\n");
 541                 fw_dump.dump_registered = 1;
 542                 err = 0;
 543                 break;
 544         }
 545         return err;
 546 }
 547
 548 void crash_fadump(struct pt_regs *regs, const char *str)
 549 {
 550         struct fadump_crash_info_header *fdh = NULL;
 551         int old_cpu, this_cpu;
 552
 553         if (!should_fadump_crash())
 554                 return;
 555
 556         /*
 557          * old_cpu == -1 means this is the first CPU which has come here,
 558          * go ahead and trigger fadump.
 559          *
 560          * old_cpu != -1 means some other CPU has already on it's way
 561          * to trigger fadump, just keep looping here.
 562          */
 563         this_cpu = smp_processor_id();
 564         old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
 565
 566         if (old_cpu != -1) {
 567                 /*
 568                  * We can't loop here indefinitely. Wait as long as fadump
 569                  * is in force. If we race with fadump un-registration this
 570                  * loop will break and then we go down to normal panic path
 571                  * and reboot. If fadump is in force the first crashing
 572                  * cpu will definitely trigger fadump.
 573                  */
 574                 while (fw_dump.dump_registered)
 575                         cpu_relax();
 576                 return;
 577         }
 578
 579         fdh = __va(fw_dump.fadumphdr_addr);
 580         fdh->crashing_cpu = crashing_cpu;
 581         crash_save_vmcoreinfo();
 582
 583         if (regs)
 584                 fdh->regs = *regs;
 585         else
 586                 ppc_save_regs(&fdh->regs);
 587
 588         fdh->online_mask = *cpu_online_mask;
 589
 590         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
 591         rtas_os_term((char *)str);
 592 }
 593
 594 #define GPR_MASK        0xffffff0000000000
 595 static inline int fadump_gpr_index(u64 id)
 596 {
 597         int i = -1;
 598         char str[3];
 599
 600         if ((id & GPR_MASK) == REG_ID("GPR")) {
 601                 /* get the digits at the end */
 602                 id &= ~GPR_MASK;
 603                 id >>= 24;
 604                 str[2] = '\0';
 605                 str[1] = id & 0xff;
 606                 str[0] = (id >> 8) & 0xff;
 607                 sscanf(str, "%d", &i);
 608                 if (i > 31)
 609                         i = -1;
 610         }
 611         return i;
 612 }
 613
 614 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
 615                                                                 u64 reg_val)
 616 {
 617         int i;
 618
 619         i = fadump_gpr_index(reg_id);
 620         if (i >= 0)
 621                 regs->gpr[i] = (unsigned long)reg_val;
 622         else if (reg_id == REG_ID("NIA"))
 623                 regs->nip = (unsigned long)reg_val;
 624         else if (reg_id == REG_ID("MSR"))
 625                 regs->msr = (unsigned long)reg_val;
 626         else if (reg_id == REG_ID("CTR"))
 627                 regs->ctr = (unsigned long)reg_val;
 628         else if (reg_id == REG_ID("LR"))
 629                 regs->link = (unsigned long)reg_val;
 630         else if (reg_id == REG_ID("XER"))
 631                 regs->xer = (unsigned long)reg_val;
 632         else if (reg_id == REG_ID("CR"))
 633                 regs->ccr = (unsigned long)reg_val;
 634         else if (reg_id == REG_ID("DAR"))
 635                 regs->dar = (unsigned long)reg_val;
 636         else if (reg_id == REG_ID("DSISR"))
 637                 regs->dsisr = (unsigned long)reg_val;
 638 }
 639
 640 static struct fadump_reg_entry*
 641 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 642 {
 643         memset(regs, 0, sizeof(struct pt_regs));
 644
 645         while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
 646                 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
 647                                         be64_to_cpu(reg_entry->reg_value));
 648                 reg_entry++;
 649         }
 650         reg_entry++;
 651         return reg_entry;
 652 }
 653
 654 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 655 {
 656         struct elf_prstatus prstatus;
 657
 658         memset(&prstatus, 0, sizeof(prstatus));
 659         /*
 660          * FIXME: How do i get PID? Do I really need it?
 661          * prstatus.pr_pid = ????
 662          */
 663         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 664         buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
 665                               &prstatus, sizeof(prstatus));
 666         return buf;
 667 }
 668
 669 static void fadump_update_elfcore_header(char *bufp)
 670 {
 671         struct elfhdr *elf;
 672         struct elf_phdr *phdr;
 673
 674         elf = (struct elfhdr *)bufp;
 675         bufp += sizeof(struct elfhdr);
 676
 677         /* First note is a place holder for cpu notes info. */
 678         phdr = (struct elf_phdr *)bufp;
 679
 680         if (phdr->p_type == PT_NOTE) {
 681                 phdr->p_paddr = fw_dump.cpu_notes_buf;
 682                 phdr->p_offset  = phdr->p_paddr;
 683                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
 684                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
 685         }
 686         return;
 687 }
 688
 689 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
 690 {
 691         void *vaddr;
 692         struct page *page;
 693         unsigned long order, count, i;
 694
 695         order = get_order(size);
 696         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
 697         if (!vaddr)
 698                 return NULL;
 699
 700         count = 1 << order;
 701         page = virt_to_page(vaddr);
 702         for (i = 0; i < count; i++)
 703                 SetPageReserved(page + i);
 704         return vaddr;
 705 }
 706
 707 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
 708 {
 709         struct page *page;
 710         unsigned long order, count, i;
 711
 712         order = get_order(size);
 713         count = 1 << order;
 714         page = virt_to_page(vaddr);
 715         for (i = 0; i < count; i++)
 716                 ClearPageReserved(page + i);
 717         __free_pages(page, order);
 718 }
 719
 720 /*
 721  * Read CPU state dump data and convert it into ELF notes.
 722  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
 723  * used to access the data to allow for additional fields to be added without
 724  * affecting compatibility. Each list of registers for a CPU starts with
 725  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
 726  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
 727  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
 728  * of register value. For more details refer to PAPR document.
 729  *
 730  * Only for the crashing cpu we ignore the CPU dump data and get exact
 731  * state from fadump crash info structure populated by first kernel at the
 732  * time of crash.
 733  */
 734 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 735 {
 736         struct fadump_reg_save_area_header *reg_header;
 737         struct fadump_reg_entry *reg_entry;
 738         struct fadump_crash_info_header *fdh = NULL;
 739         void *vaddr;
 740         unsigned long addr;
 741         u32 num_cpus, *note_buf;
 742         struct pt_regs regs;
 743         int i, rc = 0, cpu = 0;
 744
 745         if (!fdm->cpu_state_data.bytes_dumped)
 746                 return -EINVAL;
 747
 748         addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
 749         vaddr = __va(addr);
 750
 751         reg_header = vaddr;
 752         if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
 753                 printk(KERN_ERR "Unable to read register save area.\n");
 754                 return -ENOENT;
 755         }
 756         pr_debug("--------CPU State Data------------\n");
 757         pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
 758         pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
 759
 760         vaddr += be32_to_cpu(reg_header->num_cpu_offset);
 761         num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
 762         pr_debug("NumCpus     : %u\n", num_cpus);
 763         vaddr += sizeof(u32);
 764         reg_entry = (struct fadump_reg_entry *)vaddr;
 765
 766         /* Allocate buffer to hold cpu crash notes. */
 767         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
 768         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
 769         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
 770         if (!note_buf) {
 771                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
 772                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
 773                 return -ENOMEM;
 774         }
 775         fw_dump.cpu_notes_buf = __pa(note_buf);
 776
 777         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
 778                         (num_cpus * sizeof(note_buf_t)), note_buf);
 779
 780         if (fw_dump.fadumphdr_addr)
 781                 fdh = __va(fw_dump.fadumphdr_addr);
 782
 783         for (i = 0; i < num_cpus; i++) {
 784                 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
 785                         printk(KERN_ERR "Unable to read CPU state data\n");
 786                         rc = -ENOENT;
 787                         goto error_out;
 788                 }
 789                 /* Lower 4 bytes of reg_value contains logical cpu id */
 790                 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
 791                 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
 792                         SKIP_TO_NEXT_CPU(reg_entry);
 793                         continue;
 794                 }
 795                 pr_debug("Reading register data for cpu %d...\n", cpu);
 796                 if (fdh && fdh->crashing_cpu == cpu) {
 797                         regs = fdh->regs;
 798                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 799                         SKIP_TO_NEXT_CPU(reg_entry);
 800                 } else {
 801                         reg_entry++;
 802                         reg_entry = fadump_read_registers(reg_entry, &regs);
 803                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 804                 }
 805         }
 806         final_note(note_buf);
 807
 808         if (fdh) {
 809                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 810                                                         fdh->elfcorehdr_addr);
 811                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 812         }
 813         return 0;
 814
 815 error_out:
 816         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 817                                         fw_dump.cpu_notes_buf_size);
 818         fw_dump.cpu_notes_buf = 0;
 819         fw_dump.cpu_notes_buf_size = 0;
 820         return rc;
 821
 822 }
 823
 824 /*
 825  * Validate and process the dump data stored by firmware before exporting
 826  * it through '/proc/vmcore'.
 827  */
 828 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 829 {
 830         struct fadump_crash_info_header *fdh;
 831         int rc = 0;
 832
 833         if (!fdm_active || !fw_dump.fadumphdr_addr)
 834                 return -EINVAL;
 835
 836         /* Check if the dump data is valid. */
 837         if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
 838                         (fdm_active->cpu_state_data.error_flags != 0) ||
 839                         (fdm_active->rmr_region.error_flags != 0)) {
 840                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 841                 return -EINVAL;
 842         }
 843         if ((fdm_active->rmr_region.bytes_dumped !=
 844                         fdm_active->rmr_region.source_len) ||
 845                         !fdm_active->cpu_state_data.bytes_dumped) {
 846                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 847                 return -EINVAL;
 848         }
 849
 850         /* Validate the fadump crash info header */
 851         fdh = __va(fw_dump.fadumphdr_addr);
 852         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 853                 printk(KERN_ERR "Crash info header is not valid.\n");
 854                 return -EINVAL;
 855         }
 856
 857         rc = fadump_build_cpu_notes(fdm_active);
 858         if (rc)
 859                 return rc;
 860
 861         /*
 862          * We are done validating dump info and elfcore header is now ready
 863          * to be exported. set elfcorehdr_addr so that vmcore module will
 864          * export the elfcore header through '/proc/vmcore'.
 865          */
 866         elfcorehdr_addr = fdh->elfcorehdr_addr;
 867
 868         return 0;
 869 }
 870
 871 static inline void fadump_add_crash_memory(unsigned long long base,
 872                                         unsigned long long end)
 873 {
 874         if (base == end)
 875                 return;
 876
 877         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 878                 crash_mem_ranges, base, end - 1, (end - base));
 879         crash_memory_ranges[crash_mem_ranges].base = base;
 880         crash_memory_ranges[crash_mem_ranges].size = end - base;
 881         crash_mem_ranges++;
 882 }
 883
 884 static void fadump_exclude_reserved_area(unsigned long long start,
 885                                         unsigned long long end)
 886 {
 887         unsigned long long ra_start, ra_end;
 888
 889         ra_start = fw_dump.reserve_dump_area_start;
 890         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 891
 892         if ((ra_start < end) && (ra_end > start)) {
 893                 if ((start < ra_start) && (end > ra_end)) {
 894                         fadump_add_crash_memory(start, ra_start);
 895                         fadump_add_crash_memory(ra_end, end);
 896                 } else if (start < ra_start) {
 897                         fadump_add_crash_memory(start, ra_start);
 898                 } else if (ra_end < end) {
 899                         fadump_add_crash_memory(ra_end, end);
 900                 }
 901         } else
 902                 fadump_add_crash_memory(start, end);
 903 }
 904
 905 static int fadump_init_elfcore_header(char *bufp)
 906 {
 907         struct elfhdr *elf;
 908
 909         elf = (struct elfhdr *) bufp;
 910         bufp += sizeof(struct elfhdr);
 911         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 912         elf->e_ident[EI_CLASS] = ELF_CLASS;
 913         elf->e_ident[EI_DATA] = ELF_DATA;
 914         elf->e_ident[EI_VERSION] = EV_CURRENT;
 915         elf->e_ident[EI_OSABI] = ELF_OSABI;
 916         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 917         elf->e_type = ET_CORE;
 918         elf->e_machine = ELF_ARCH;
 919         elf->e_version = EV_CURRENT;
 920         elf->e_entry = 0;
 921         elf->e_phoff = sizeof(struct elfhdr);
 922         elf->e_shoff = 0;
 923 #if defined(_CALL_ELF)
 924         elf->e_flags = _CALL_ELF;
 925 #else
 926         elf->e_flags = 0;
 927 #endif
 928         elf->e_ehsize = sizeof(struct elfhdr);
 929         elf->e_phentsize = sizeof(struct elf_phdr);
 930         elf->e_phnum = 0;
 931         elf->e_shentsize = 0;
 932         elf->e_shnum = 0;
 933         elf->e_shstrndx = 0;
 934
 935         return 0;
 936 }
 937
 938 /*
 939  * Traverse through memblock structure and setup crash memory ranges. These
 940  * ranges will be used create PT_LOAD program headers in elfcore header.
 941  */
 942 static void fadump_setup_crash_memory_ranges(void)
 943 {
 944         struct memblock_region *reg;
 945         unsigned long long start, end;
 946
 947         pr_debug("Setup crash memory ranges.\n");
 948         crash_mem_ranges = 0;
 949         /*
 950          * add the first memory chunk (RMA_START through boot_memory_size) as
 951          * a separate memory chunk. The reason is, at the time crash firmware
 952          * will move the content of this memory chunk to different location
 953          * specified during fadump registration. We need to create a separate
 954          * program header for this chunk with the correct offset.
 955          */
 956         fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 957
 958         for_each_memblock(memory, reg) {
 959                 start = (unsigned long long)reg->base;
 960                 end = start + (unsigned long long)reg->size;
 961
 962                 /*
 963                  * skip the first memory chunk that is already added (RMA_START
 964                  * through boot_memory_size). This logic needs a relook if and
 965                  * when RMA_START changes to a non-zero value.
 966                  */
 967                 BUILD_BUG_ON(RMA_START != 0);
 968                 if (start < fw_dump.boot_memory_size) {
 969                         if (end > fw_dump.boot_memory_size)
 970                                 start = fw_dump.boot_memory_size;
 971                         else
 972                                 continue;
 973                 }
 974
 975                 /* add this range excluding the reserved dump area. */
 976                 fadump_exclude_reserved_area(start, end);
 977         }
 978 }
 979
 980 /*
 981  * If the given physical address falls within the boot memory region then
 982  * return the relocated address that points to the dump region reserved
 983  * for saving initial boot memory contents.
 984  */
 985 static inline unsigned long fadump_relocate(unsigned long paddr)
 986 {
 987         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 988                 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
 989         else
 990                 return paddr;
 991 }
 992
 993 static int fadump_create_elfcore_headers(char *bufp)
 994 {
 995         struct elfhdr *elf;
 996         struct elf_phdr *phdr;
 997         int i;
 998
 999         fadump_init_elfcore_header(bufp);
1000         elf = (struct elfhdr *)bufp;
1001         bufp += sizeof(struct elfhdr);
1002
1003         /*
1004          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
1005          * will be populated during second kernel boot after crash. Hence
1006          * this PT_NOTE will always be the first elf note.
1007          *
1008          * NOTE: Any new ELF note addition should be placed after this note.
1009          */
1010         phdr = (struct elf_phdr *)bufp;
1011         bufp += sizeof(struct elf_phdr);
1012         phdr->p_type = PT_NOTE;
1013         phdr->p_flags = 0;
1014         phdr->p_vaddr = 0;
1015         phdr->p_align = 0;
1016
1017         phdr->p_offset = 0;
1018         phdr->p_paddr = 0;
1019         phdr->p_filesz = 0;
1020         phdr->p_memsz = 0;
1021
1022         (elf->e_phnum)++;
1023
1024         /* setup ELF PT_NOTE for vmcoreinfo */
1025         phdr = (struct elf_phdr *)bufp;
1026         bufp += sizeof(struct elf_phdr);
1027         phdr->p_type    = PT_NOTE;
1028         phdr->p_flags   = 0;
1029         phdr->p_vaddr   = 0;
1030         phdr->p_align   = 0;
1031
1032         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
1033         phdr->p_offset  = phdr->p_paddr;
1034         phdr->p_memsz   = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1035
1036         /* Increment number of program headers. */
1037         (elf->e_phnum)++;
1038
1039         /* setup PT_LOAD sections. */
1040
1041         for (i = 0; i < crash_mem_ranges; i++) {
1042                 unsigned long long mbase, msize;
1043                 mbase = crash_memory_ranges[i].base;
1044                 msize = crash_memory_ranges[i].size;
1045
1046                 if (!msize)
1047                         continue;
1048
1049                 phdr = (struct elf_phdr *)bufp;
1050                 bufp += sizeof(struct elf_phdr);
1051                 phdr->p_type    = PT_LOAD;
1052                 phdr->p_flags   = PF_R|PF_W|PF_X;
1053                 phdr->p_offset  = mbase;
1054
1055                 if (mbase == RMA_START) {
1056                         /*
1057                          * The entire RMA region will be moved by firmware
1058                          * to the specified destination_address. Hence set
1059                          * the correct offset.
1060                          */
1061                         phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
1062                 }
1063
1064                 phdr->p_paddr = mbase;
1065                 phdr->p_vaddr = (unsigned long)__va(mbase);
1066                 phdr->p_filesz = msize;
1067                 phdr->p_memsz = msize;
1068                 phdr->p_align = 0;
1069
1070                 /* Increment number of program headers. */
1071                 (elf->e_phnum)++;
1072         }
1073         return 0;
1074 }
1075
1076 static unsigned long init_fadump_header(unsigned long addr)
1077 {
1078         struct fadump_crash_info_header *fdh;
1079
1080         if (!addr)
1081                 return 0;
1082
1083         fw_dump.fadumphdr_addr = addr;
1084         fdh = __va(addr);
1085         addr += sizeof(struct fadump_crash_info_header);
1086
1087         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1088         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1089         fdh->elfcorehdr_addr = addr;
1090         /* We will set the crashing cpu id in crash_fadump() during crash. */
1091         fdh->crashing_cpu = CPU_UNKNOWN;
1092
1093         return addr;
1094 }
1095
1096 static int register_fadump(void)
1097 {
1098         unsigned long addr;
1099         void *vaddr;
1100
1101         /*
1102          * If no memory is reserved then we can not register for firmware-
1103          * assisted dump.
1104          */
1105         if (!fw_dump.reserve_dump_area_size)
1106                 return -ENODEV;
1107
1108         fadump_setup_crash_memory_ranges();
1109
1110         addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1111         /* Initialize fadump crash info header. */
1112         addr = init_fadump_header(addr);
1113         vaddr = __va(addr);
1114
1115         pr_debug("Creating ELF core headers at %#016lx\n", addr);
1116         fadump_create_elfcore_headers(vaddr);
1117
1118         /* register the future kernel dump with firmware. */
1119         return register_fw_dump(&fdm);
1120 }
1121
1122 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1123 {
1124         int rc = 0;
1125         unsigned int wait_time;
1126
1127         pr_debug("Un-register firmware-assisted dump\n");
1128
1129         /* TODO: Add upper time limit for the delay */
1130         do {
1131                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1132                         FADUMP_UNREGISTER, fdm,
1133                         sizeof(struct fadump_mem_struct));
1134
1135                 wait_time = rtas_busy_delay_time(rc);
1136                 if (wait_time)
1137                         mdelay(wait_time);
1138         } while (wait_time);
1139
1140         if (rc) {
1141                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1142                         " unexpected error(%d).\n", rc);
1143                 return rc;
1144         }
1145         fw_dump.dump_registered = 0;
1146         return 0;
1147 }
1148
1149 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1150 {
1151         int rc = 0;
1152         unsigned int wait_time;
1153
1154         pr_debug("Invalidating firmware-assisted dump registration\n");
1155
1156         /* TODO: Add upper time limit for the delay */
1157         do {
1158                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1159                         FADUMP_INVALIDATE, fdm,
1160                         sizeof(struct fadump_mem_struct));
1161
1162                 wait_time = rtas_busy_delay_time(rc);
1163                 if (wait_time)
1164                         mdelay(wait_time);
1165         } while (wait_time);
1166
1167         if (rc) {
1168                 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1169                 return rc;
1170         }
1171         fw_dump.dump_active = 0;
1172         fdm_active = NULL;
1173         return 0;
1174 }
1175
1176 void fadump_cleanup(void)
1177 {
1178         /* Invalidate the registration only if dump is active. */
1179         if (fw_dump.dump_active) {
1180                 init_fadump_mem_struct(&fdm,
1181                         be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1182                 fadump_invalidate_dump(&fdm);
1183         } else if (fw_dump.dump_registered) {
1184                 /* Un-register Firmware-assisted dump if it was registered. */
1185                 fadump_unregister_dump(&fdm);
1186         }
1187 }
1188
1189 static void fadump_free_reserved_memory(unsigned long start_pfn,
1190                                         unsigned long end_pfn)
1191 {
1192         unsigned long pfn;
1193         unsigned long time_limit = jiffies + HZ;
1194
1195         pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1196                 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1197
1198         for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1199                 free_reserved_page(pfn_to_page(pfn));
1200
1201                 if (time_after(jiffies, time_limit)) {
1202                         cond_resched();
1203                         time_limit = jiffies + HZ;
1204                 }
1205         }
1206 }
1207
1208 /*
1209  * Skip memory holes and free memory that was actually reserved.
1210  */
1211 static void fadump_release_reserved_area(unsigned long start, unsigned long end)
1212 {
1213         struct memblock_region *reg;
1214         unsigned long tstart, tend;
1215         unsigned long start_pfn = PHYS_PFN(start);
1216         unsigned long end_pfn = PHYS_PFN(end);
1217
1218         for_each_memblock(memory, reg) {
1219                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
1220                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
1221                 if (tstart < tend) {
1222                         fadump_free_reserved_memory(tstart, tend);
1223
1224                         if (tend == end_pfn)
1225                                 break;
1226
1227                         start_pfn = tend + 1;
1228                 }
1229         }
1230 }
1231
1232 /*
1233  * Release the memory that was reserved in early boot to preserve the memory
1234  * contents. The released memory will be available for general use.
1235  */
1236 static void fadump_release_memory(unsigned long begin, unsigned long end)
1237 {
1238         unsigned long ra_start, ra_end;
1239
1240         ra_start = fw_dump.reserve_dump_area_start;
1241         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1242
1243         /*
1244          * exclude the dump reserve area. Will reuse it for next
1245          * fadump registration.
1246          */
1247         if (begin < ra_end && end > ra_start) {
1248                 if (begin < ra_start)
1249                         fadump_release_reserved_area(begin, ra_start);
1250                 if (end > ra_end)
1251                         fadump_release_reserved_area(ra_end, end);
1252         } else
1253                 fadump_release_reserved_area(begin, end);
1254 }
1255
1256 static void fadump_invalidate_release_mem(void)
1257 {
1258         unsigned long reserved_area_start, reserved_area_end;
1259         unsigned long destination_address;
1260
1261         mutex_lock(&fadump_mutex);
1262         if (!fw_dump.dump_active) {
1263                 mutex_unlock(&fadump_mutex);
1264                 return;
1265         }
1266
1267         destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1268         fadump_cleanup();
1269         mutex_unlock(&fadump_mutex);
1270
1271         /*
1272          * Save the current reserved memory bounds we will require them
1273          * later for releasing the memory for general use.
1274          */
1275         reserved_area_start = fw_dump.reserve_dump_area_start;
1276         reserved_area_end = reserved_area_start +
1277                         fw_dump.reserve_dump_area_size;
1278         /*
1279          * Setup reserve_dump_area_start and its size so that we can
1280          * reuse this reserved memory for Re-registration.
1281          */
1282         fw_dump.reserve_dump_area_start = destination_address;
1283         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1284
1285         fadump_release_memory(reserved_area_start, reserved_area_end);
1286         if (fw_dump.cpu_notes_buf) {
1287                 fadump_cpu_notes_buf_free(
1288                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1289                                 fw_dump.cpu_notes_buf_size);
1290                 fw_dump.cpu_notes_buf = 0;
1291                 fw_dump.cpu_notes_buf_size = 0;
1292         }
1293         /* Initialize the kernel dump memory structure for FAD registration. */
1294         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1295 }
1296
1297 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1298                                         struct kobj_attribute *attr,
1299                                         const char *buf, size_t count)
1300 {
1301         int input = -1;
1302
1303         if (!fw_dump.dump_active)
1304                 return -EPERM;
1305
1306         if (kstrtoint(buf, 0, &input))
1307                 return -EINVAL;
1308
1309         if (input == 1) {
1310                 /*
1311                  * Take away the '/proc/vmcore'. We are releasing the dump
1312                  * memory, hence it will not be valid anymore.
1313                  */
1314 #ifdef CONFIG_PROC_VMCORE
1315                 vmcore_cleanup();
1316 #endif
1317                 fadump_invalidate_release_mem();
1318
1319         } else
1320                 return -EINVAL;
1321         return count;
1322 }
1323
1324 static ssize_t fadump_enabled_show(struct kobject *kobj,
1325                                         struct kobj_attribute *attr,
1326                                         char *buf)
1327 {
1328         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1329 }
1330
1331 static ssize_t fadump_register_show(struct kobject *kobj,
1332                                         struct kobj_attribute *attr,
1333                                         char *buf)
1334 {
1335         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1336 }
1337
1338 static ssize_t fadump_register_store(struct kobject *kobj,
1339                                         struct kobj_attribute *attr,
1340                                         const char *buf, size_t count)
1341 {
1342         int ret = 0;
1343         int input = -1;
1344
1345         if (!fw_dump.fadump_enabled || fdm_active)
1346                 return -EPERM;
1347
1348         if (kstrtoint(buf, 0, &input))
1349                 return -EINVAL;
1350
1351         mutex_lock(&fadump_mutex);
1352
1353         switch (input) {
1354         case 0:
1355                 if (fw_dump.dump_registered == 0) {
1356                         goto unlock_out;
1357                 }
1358                 /* Un-register Firmware-assisted dump */
1359                 fadump_unregister_dump(&fdm);
1360                 break;
1361         case 1:
1362                 if (fw_dump.dump_registered == 1) {
1363                         ret = -EEXIST;
1364                         goto unlock_out;
1365                 }
1366                 /* Register Firmware-assisted dump */
1367                 ret = register_fadump();
1368                 break;
1369         default:
1370                 ret = -EINVAL;
1371                 break;
1372         }
1373
1374 unlock_out:
1375         mutex_unlock(&fadump_mutex);
1376         return ret < 0 ? ret : count;
1377 }
1378
1379 static int fadump_region_show(struct seq_file *m, void *private)
1380 {
1381         const struct fadump_mem_struct *fdm_ptr;
1382
1383         if (!fw_dump.fadump_enabled)
1384                 return 0;
1385
1386         mutex_lock(&fadump_mutex);
1387         if (fdm_active)
1388                 fdm_ptr = fdm_active;
1389         else {
1390                 mutex_unlock(&fadump_mutex);
1391                 fdm_ptr = &fdm;
1392         }
1393
1394         seq_printf(m,
1395                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1396                         "Dumped: %#llx\n",
1397                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1398                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1399                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1400                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1401                         be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1402         seq_printf(m,
1403                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1404                         "Dumped: %#llx\n",
1405                         be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1406                         be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1407                         be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1408                         be64_to_cpu(fdm_ptr->hpte_region.source_len),
1409                         be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1410         seq_printf(m,
1411                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1412                         "Dumped: %#llx\n",
1413                         be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1414                         be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1415                         be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1416                         be64_to_cpu(fdm_ptr->rmr_region.source_len),
1417                         be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1418
1419         if (!fdm_active ||
1420                 (fw_dump.reserve_dump_area_start ==
1421                 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1422                 goto out;
1423
1424         /* Dump is active. Show reserved memory region. */
1425         seq_printf(m,
1426                         "    : [%#016llx-%#016llx] %#llx bytes, "
1427                         "Dumped: %#llx\n",
1428                         (unsigned long long)fw_dump.reserve_dump_area_start,
1429                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1430                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1431                         fw_dump.reserve_dump_area_start,
1432                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1433                         fw_dump.reserve_dump_area_start);
1434 out:
1435         if (fdm_active)
1436                 mutex_unlock(&fadump_mutex);
1437         return 0;
1438 }
1439
1440 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1441                                                 0200, NULL,
1442                                                 fadump_release_memory_store);
1443 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1444                                                 0444, fadump_enabled_show,
1445                                                 NULL);
1446 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1447                                                 0644, fadump_register_show,
1448                                                 fadump_register_store);
1449
1450 static int fadump_region_open(struct inode *inode, struct file *file)
1451 {
1452         return single_open(file, fadump_region_show, inode->i_private);
1453 }
1454
1455 static const struct file_operations fadump_region_fops = {
1456         .open    = fadump_region_open,
1457         .read    = seq_read,
1458         .llseek  = seq_lseek,
1459         .release = single_release,
1460 };
1461
1462 static void fadump_init_files(void)
1463 {
1464         struct dentry *debugfs_file;
1465         int rc = 0;
1466
1467         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1468         if (rc)
1469                 printk(KERN_ERR "fadump: unable to create sysfs file"
1470                         " fadump_enabled (%d)\n", rc);
1471
1472         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1473         if (rc)
1474                 printk(KERN_ERR "fadump: unable to create sysfs file"
1475                         " fadump_registered (%d)\n", rc);
1476
1477         debugfs_file = debugfs_create_file("fadump_region", 0444,
1478                                         powerpc_debugfs_root, NULL,
1479                                         &fadump_region_fops);
1480         if (!debugfs_file)
1481                 printk(KERN_ERR "fadump: unable to create debugfs file"
1482                                 " fadump_region\n");
1483
1484         if (fw_dump.dump_active) {
1485                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1486                 if (rc)
1487                         printk(KERN_ERR "fadump: unable to create sysfs file"
1488                                 " fadump_release_mem (%d)\n", rc);
1489         }
1490         return;
1491 }
1492
1493 /*
1494  * Prepare for firmware-assisted dump.
1495  */
1496 int __init setup_fadump(void)
1497 {
1498         if (!fw_dump.fadump_enabled)
1499                 return 0;
1500
1501         if (!fw_dump.fadump_supported) {
1502                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1503                         " this hardware\n");
1504                 return 0;
1505         }
1506
1507         fadump_show_config();
1508         /*
1509          * If dump data is available then see if it is valid and prepare for
1510          * saving it to the disk.
1511          */
1512         if (fw_dump.dump_active) {
1513                 /*
1514                  * if dump process fails then invalidate the registration
1515                  * and release memory before proceeding for re-registration.
1516                  */
1517                 if (process_fadump(fdm_active) < 0)
1518                         fadump_invalidate_release_mem();
1519         }
1520         /* Initialize the kernel dump memory structure for FAD registration. */
1521         else if (fw_dump.reserve_dump_area_size)
1522                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1523         fadump_init_files();
1524
1525         return 1;
1526 }
1527 subsys_initcall(setup_fadump);