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 int __init fadump_reserve_mem(void)
 339 {
 340         unsigned long base, size, memory_boundary;
 341
 342         if (!fw_dump.fadump_enabled)
 343                 return 0;
 344
 345         if (!fw_dump.fadump_supported) {
 346                 printk(KERN_INFO "Firmware-assisted dump is not supported on"
 347                                 " this hardware\n");
 348                 fw_dump.fadump_enabled = 0;
 349                 return 0;
 350         }
 351         /*
 352          * Initialize boot memory size
 353          * If dump is active then we have already calculated the size during
 354          * first kernel.
 355          */
 356         if (fdm_active)
 357                 fw_dump.boot_memory_size = be64_to_cpu(fdm_active->rmr_region.source_len);
 358         else
 359                 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
 360
 361         /*
 362          * Calculate the memory boundary.
 363          * If memory_limit is less than actual memory boundary then reserve
 364          * the memory for fadump beyond the memory_limit and adjust the
 365          * memory_limit accordingly, so that the running kernel can run with
 366          * specified memory_limit.
 367          */
 368         if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
 369                 size = get_fadump_area_size();
 370                 if ((memory_limit + size) < memblock_end_of_DRAM())
 371                         memory_limit += size;
 372                 else
 373                         memory_limit = memblock_end_of_DRAM();
 374                 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
 375                                 " dump, now %#016llx\n", memory_limit);
 376         }
 377         if (memory_limit)
 378                 memory_boundary = memory_limit;
 379         else
 380                 memory_boundary = memblock_end_of_DRAM();
 381
 382         if (fw_dump.dump_active) {
 383                 printk(KERN_INFO "Firmware-assisted dump is active.\n");
 384                 /*
 385                  * If last boot has crashed then reserve all the memory
 386                  * above boot_memory_size so that we don't touch it until
 387                  * dump is written to disk by userspace tool. This memory
 388                  * will be released for general use once the dump is saved.
 389                  */
 390                 base = fw_dump.boot_memory_size;
 391                 size = memory_boundary - base;
 392                 memblock_reserve(base, size);
 393                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
 394                                 "for saving crash dump\n",
 395                                 (unsigned long)(size >> 20),
 396                                 (unsigned long)(base >> 20));
 397
 398                 fw_dump.fadumphdr_addr =
 399                                 be64_to_cpu(fdm_active->rmr_region.destination_address) +
 400                                 be64_to_cpu(fdm_active->rmr_region.source_len);
 401                 pr_debug("fadumphdr_addr = %p\n",
 402                                 (void *) fw_dump.fadumphdr_addr);
 403         } else {
 404                 size = get_fadump_area_size();
 405
 406                 /*
 407                  * Reserve memory at an offset closer to bottom of the RAM to
 408                  * minimize the impact of memory hot-remove operation. We can't
 409                  * use memblock_find_in_range() here since it doesn't allocate
 410                  * from bottom to top.
 411                  */
 412                 for (base = fw_dump.boot_memory_size;
 413                      base <= (memory_boundary - size);
 414                      base += size) {
 415                         if (memblock_is_region_memory(base, size) &&
 416                             !memblock_is_region_reserved(base, size))
 417                                 break;
 418                 }
 419                 if ((base > (memory_boundary - size)) ||
 420                     memblock_reserve(base, size)) {
 421                         pr_err("Failed to reserve memory\n");
 422                         return 0;
 423                 }
 424
 425                 pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
 426                         "assisted dump (System RAM: %ldMB)\n",
 427                         (unsigned long)(size >> 20),
 428                         (unsigned long)(base >> 20),
 429                         (unsigned long)(memblock_phys_mem_size() >> 20));
 430         }
 431
 432         fw_dump.reserve_dump_area_start = base;
 433         fw_dump.reserve_dump_area_size = size;
 434         return 1;
 435 }
 436
 437 unsigned long __init arch_reserved_kernel_pages(void)
 438 {
 439         return memblock_reserved_size() / PAGE_SIZE;
 440 }
 441
 442 /* Look for fadump= cmdline option. */
 443 static int __init early_fadump_param(char *p)
 444 {
 445         if (!p)
 446                 return 1;
 447
 448         if (strncmp(p, "on", 2) == 0)
 449                 fw_dump.fadump_enabled = 1;
 450         else if (strncmp(p, "off", 3) == 0)
 451                 fw_dump.fadump_enabled = 0;
 452
 453         return 0;
 454 }
 455 early_param("fadump", early_fadump_param);
 456
 457 /*
 458  * Look for fadump_reserve_mem= cmdline option
 459  * TODO: Remove references to 'fadump_reserve_mem=' parameter,
 460  *       the sooner 'crashkernel=' parameter is accustomed to.
 461  */
 462 static int __init early_fadump_reserve_mem(char *p)
 463 {
 464         if (p)
 465                 fw_dump.reserve_bootvar = memparse(p, &p);
 466         return 0;
 467 }
 468 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
 469
 470 static int register_fw_dump(struct fadump_mem_struct *fdm)
 471 {
 472         int rc, err;
 473         unsigned int wait_time;
 474
 475         pr_debug("Registering for firmware-assisted kernel dump...\n");
 476
 477         /* TODO: Add upper time limit for the delay */
 478         do {
 479                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 480                         FADUMP_REGISTER, fdm,
 481                         sizeof(struct fadump_mem_struct));
 482
 483                 wait_time = rtas_busy_delay_time(rc);
 484                 if (wait_time)
 485                         mdelay(wait_time);
 486
 487         } while (wait_time);
 488
 489         err = -EIO;
 490         switch (rc) {
 491         default:
 492                 pr_err("Failed to register. Unknown Error(%d).\n", rc);
 493                 break;
 494         case -1:
 495                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 496                         " dump. Hardware Error(%d).\n", rc);
 497                 break;
 498         case -3:
 499                 if (!is_boot_memory_area_contiguous())
 500                         pr_err("Can't have holes in boot memory area while "
 501                                "registering fadump\n");
 502
 503                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 504                         " dump. Parameter Error(%d).\n", rc);
 505                 err = -EINVAL;
 506                 break;
 507         case -9:
 508                 printk(KERN_ERR "firmware-assisted kernel dump is already "
 509                         " registered.");
 510                 fw_dump.dump_registered = 1;
 511                 err = -EEXIST;
 512                 break;
 513         case 0:
 514                 printk(KERN_INFO "firmware-assisted kernel dump registration"
 515                         " is successful\n");
 516                 fw_dump.dump_registered = 1;
 517                 err = 0;
 518                 break;
 519         }
 520         return err;
 521 }
 522
 523 void crash_fadump(struct pt_regs *regs, const char *str)
 524 {
 525         struct fadump_crash_info_header *fdh = NULL;
 526         int old_cpu, this_cpu;
 527
 528         if (!should_fadump_crash())
 529                 return;
 530
 531         /*
 532          * old_cpu == -1 means this is the first CPU which has come here,
 533          * go ahead and trigger fadump.
 534          *
 535          * old_cpu != -1 means some other CPU has already on it's way
 536          * to trigger fadump, just keep looping here.
 537          */
 538         this_cpu = smp_processor_id();
 539         old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu);
 540
 541         if (old_cpu != -1) {
 542                 /*
 543                  * We can't loop here indefinitely. Wait as long as fadump
 544                  * is in force. If we race with fadump un-registration this
 545                  * loop will break and then we go down to normal panic path
 546                  * and reboot. If fadump is in force the first crashing
 547                  * cpu will definitely trigger fadump.
 548                  */
 549                 while (fw_dump.dump_registered)
 550                         cpu_relax();
 551                 return;
 552         }
 553
 554         fdh = __va(fw_dump.fadumphdr_addr);
 555         fdh->crashing_cpu = crashing_cpu;
 556         crash_save_vmcoreinfo();
 557
 558         if (regs)
 559                 fdh->regs = *regs;
 560         else
 561                 ppc_save_regs(&fdh->regs);
 562
 563         fdh->online_mask = *cpu_online_mask;
 564
 565         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
 566         rtas_os_term((char *)str);
 567 }
 568
 569 #define GPR_MASK        0xffffff0000000000
 570 static inline int fadump_gpr_index(u64 id)
 571 {
 572         int i = -1;
 573         char str[3];
 574
 575         if ((id & GPR_MASK) == REG_ID("GPR")) {
 576                 /* get the digits at the end */
 577                 id &= ~GPR_MASK;
 578                 id >>= 24;
 579                 str[2] = '\0';
 580                 str[1] = id & 0xff;
 581                 str[0] = (id >> 8) & 0xff;
 582                 sscanf(str, "%d", &i);
 583                 if (i > 31)
 584                         i = -1;
 585         }
 586         return i;
 587 }
 588
 589 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
 590                                                                 u64 reg_val)
 591 {
 592         int i;
 593
 594         i = fadump_gpr_index(reg_id);
 595         if (i >= 0)
 596                 regs->gpr[i] = (unsigned long)reg_val;
 597         else if (reg_id == REG_ID("NIA"))
 598                 regs->nip = (unsigned long)reg_val;
 599         else if (reg_id == REG_ID("MSR"))
 600                 regs->msr = (unsigned long)reg_val;
 601         else if (reg_id == REG_ID("CTR"))
 602                 regs->ctr = (unsigned long)reg_val;
 603         else if (reg_id == REG_ID("LR"))
 604                 regs->link = (unsigned long)reg_val;
 605         else if (reg_id == REG_ID("XER"))
 606                 regs->xer = (unsigned long)reg_val;
 607         else if (reg_id == REG_ID("CR"))
 608                 regs->ccr = (unsigned long)reg_val;
 609         else if (reg_id == REG_ID("DAR"))
 610                 regs->dar = (unsigned long)reg_val;
 611         else if (reg_id == REG_ID("DSISR"))
 612                 regs->dsisr = (unsigned long)reg_val;
 613 }
 614
 615 static struct fadump_reg_entry*
 616 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 617 {
 618         memset(regs, 0, sizeof(struct pt_regs));
 619
 620         while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
 621                 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
 622                                         be64_to_cpu(reg_entry->reg_value));
 623                 reg_entry++;
 624         }
 625         reg_entry++;
 626         return reg_entry;
 627 }
 628
 629 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 630 {
 631         struct elf_prstatus prstatus;
 632
 633         memset(&prstatus, 0, sizeof(prstatus));
 634         /*
 635          * FIXME: How do i get PID? Do I really need it?
 636          * prstatus.pr_pid = ????
 637          */
 638         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 639         buf = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS,
 640                               &prstatus, sizeof(prstatus));
 641         return buf;
 642 }
 643
 644 static void fadump_update_elfcore_header(char *bufp)
 645 {
 646         struct elfhdr *elf;
 647         struct elf_phdr *phdr;
 648
 649         elf = (struct elfhdr *)bufp;
 650         bufp += sizeof(struct elfhdr);
 651
 652         /* First note is a place holder for cpu notes info. */
 653         phdr = (struct elf_phdr *)bufp;
 654
 655         if (phdr->p_type == PT_NOTE) {
 656                 phdr->p_paddr = fw_dump.cpu_notes_buf;
 657                 phdr->p_offset  = phdr->p_paddr;
 658                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
 659                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
 660         }
 661         return;
 662 }
 663
 664 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
 665 {
 666         void *vaddr;
 667         struct page *page;
 668         unsigned long order, count, i;
 669
 670         order = get_order(size);
 671         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
 672         if (!vaddr)
 673                 return NULL;
 674
 675         count = 1 << order;
 676         page = virt_to_page(vaddr);
 677         for (i = 0; i < count; i++)
 678                 SetPageReserved(page + i);
 679         return vaddr;
 680 }
 681
 682 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
 683 {
 684         struct page *page;
 685         unsigned long order, count, i;
 686
 687         order = get_order(size);
 688         count = 1 << order;
 689         page = virt_to_page(vaddr);
 690         for (i = 0; i < count; i++)
 691                 ClearPageReserved(page + i);
 692         __free_pages(page, order);
 693 }
 694
 695 /*
 696  * Read CPU state dump data and convert it into ELF notes.
 697  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
 698  * used to access the data to allow for additional fields to be added without
 699  * affecting compatibility. Each list of registers for a CPU starts with
 700  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
 701  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
 702  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
 703  * of register value. For more details refer to PAPR document.
 704  *
 705  * Only for the crashing cpu we ignore the CPU dump data and get exact
 706  * state from fadump crash info structure populated by first kernel at the
 707  * time of crash.
 708  */
 709 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 710 {
 711         struct fadump_reg_save_area_header *reg_header;
 712         struct fadump_reg_entry *reg_entry;
 713         struct fadump_crash_info_header *fdh = NULL;
 714         void *vaddr;
 715         unsigned long addr;
 716         u32 num_cpus, *note_buf;
 717         struct pt_regs regs;
 718         int i, rc = 0, cpu = 0;
 719
 720         if (!fdm->cpu_state_data.bytes_dumped)
 721                 return -EINVAL;
 722
 723         addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
 724         vaddr = __va(addr);
 725
 726         reg_header = vaddr;
 727         if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
 728                 printk(KERN_ERR "Unable to read register save area.\n");
 729                 return -ENOENT;
 730         }
 731         pr_debug("--------CPU State Data------------\n");
 732         pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
 733         pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
 734
 735         vaddr += be32_to_cpu(reg_header->num_cpu_offset);
 736         num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
 737         pr_debug("NumCpus     : %u\n", num_cpus);
 738         vaddr += sizeof(u32);
 739         reg_entry = (struct fadump_reg_entry *)vaddr;
 740
 741         /* Allocate buffer to hold cpu crash notes. */
 742         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
 743         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
 744         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
 745         if (!note_buf) {
 746                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
 747                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
 748                 return -ENOMEM;
 749         }
 750         fw_dump.cpu_notes_buf = __pa(note_buf);
 751
 752         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
 753                         (num_cpus * sizeof(note_buf_t)), note_buf);
 754
 755         if (fw_dump.fadumphdr_addr)
 756                 fdh = __va(fw_dump.fadumphdr_addr);
 757
 758         for (i = 0; i < num_cpus; i++) {
 759                 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
 760                         printk(KERN_ERR "Unable to read CPU state data\n");
 761                         rc = -ENOENT;
 762                         goto error_out;
 763                 }
 764                 /* Lower 4 bytes of reg_value contains logical cpu id */
 765                 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
 766                 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
 767                         SKIP_TO_NEXT_CPU(reg_entry);
 768                         continue;
 769                 }
 770                 pr_debug("Reading register data for cpu %d...\n", cpu);
 771                 if (fdh && fdh->crashing_cpu == cpu) {
 772                         regs = fdh->regs;
 773                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 774                         SKIP_TO_NEXT_CPU(reg_entry);
 775                 } else {
 776                         reg_entry++;
 777                         reg_entry = fadump_read_registers(reg_entry, &regs);
 778                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 779                 }
 780         }
 781         final_note(note_buf);
 782
 783         if (fdh) {
 784                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 785                                                         fdh->elfcorehdr_addr);
 786                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 787         }
 788         return 0;
 789
 790 error_out:
 791         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 792                                         fw_dump.cpu_notes_buf_size);
 793         fw_dump.cpu_notes_buf = 0;
 794         fw_dump.cpu_notes_buf_size = 0;
 795         return rc;
 796
 797 }
 798
 799 /*
 800  * Validate and process the dump data stored by firmware before exporting
 801  * it through '/proc/vmcore'.
 802  */
 803 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 804 {
 805         struct fadump_crash_info_header *fdh;
 806         int rc = 0;
 807
 808         if (!fdm_active || !fw_dump.fadumphdr_addr)
 809                 return -EINVAL;
 810
 811         /* Check if the dump data is valid. */
 812         if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
 813                         (fdm_active->cpu_state_data.error_flags != 0) ||
 814                         (fdm_active->rmr_region.error_flags != 0)) {
 815                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 816                 return -EINVAL;
 817         }
 818         if ((fdm_active->rmr_region.bytes_dumped !=
 819                         fdm_active->rmr_region.source_len) ||
 820                         !fdm_active->cpu_state_data.bytes_dumped) {
 821                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 822                 return -EINVAL;
 823         }
 824
 825         /* Validate the fadump crash info header */
 826         fdh = __va(fw_dump.fadumphdr_addr);
 827         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 828                 printk(KERN_ERR "Crash info header is not valid.\n");
 829                 return -EINVAL;
 830         }
 831
 832         rc = fadump_build_cpu_notes(fdm_active);
 833         if (rc)
 834                 return rc;
 835
 836         /*
 837          * We are done validating dump info and elfcore header is now ready
 838          * to be exported. set elfcorehdr_addr so that vmcore module will
 839          * export the elfcore header through '/proc/vmcore'.
 840          */
 841         elfcorehdr_addr = fdh->elfcorehdr_addr;
 842
 843         return 0;
 844 }
 845
 846 static inline void fadump_add_crash_memory(unsigned long long base,
 847                                         unsigned long long end)
 848 {
 849         if (base == end)
 850                 return;
 851
 852         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 853                 crash_mem_ranges, base, end - 1, (end - base));
 854         crash_memory_ranges[crash_mem_ranges].base = base;
 855         crash_memory_ranges[crash_mem_ranges].size = end - base;
 856         crash_mem_ranges++;
 857 }
 858
 859 static void fadump_exclude_reserved_area(unsigned long long start,
 860                                         unsigned long long end)
 861 {
 862         unsigned long long ra_start, ra_end;
 863
 864         ra_start = fw_dump.reserve_dump_area_start;
 865         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 866
 867         if ((ra_start < end) && (ra_end > start)) {
 868                 if ((start < ra_start) && (end > ra_end)) {
 869                         fadump_add_crash_memory(start, ra_start);
 870                         fadump_add_crash_memory(ra_end, end);
 871                 } else if (start < ra_start) {
 872                         fadump_add_crash_memory(start, ra_start);
 873                 } else if (ra_end < end) {
 874                         fadump_add_crash_memory(ra_end, end);
 875                 }
 876         } else
 877                 fadump_add_crash_memory(start, end);
 878 }
 879
 880 static int fadump_init_elfcore_header(char *bufp)
 881 {
 882         struct elfhdr *elf;
 883
 884         elf = (struct elfhdr *) bufp;
 885         bufp += sizeof(struct elfhdr);
 886         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 887         elf->e_ident[EI_CLASS] = ELF_CLASS;
 888         elf->e_ident[EI_DATA] = ELF_DATA;
 889         elf->e_ident[EI_VERSION] = EV_CURRENT;
 890         elf->e_ident[EI_OSABI] = ELF_OSABI;
 891         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 892         elf->e_type = ET_CORE;
 893         elf->e_machine = ELF_ARCH;
 894         elf->e_version = EV_CURRENT;
 895         elf->e_entry = 0;
 896         elf->e_phoff = sizeof(struct elfhdr);
 897         elf->e_shoff = 0;
 898 #if defined(_CALL_ELF)
 899         elf->e_flags = _CALL_ELF;
 900 #else
 901         elf->e_flags = 0;
 902 #endif
 903         elf->e_ehsize = sizeof(struct elfhdr);
 904         elf->e_phentsize = sizeof(struct elf_phdr);
 905         elf->e_phnum = 0;
 906         elf->e_shentsize = 0;
 907         elf->e_shnum = 0;
 908         elf->e_shstrndx = 0;
 909
 910         return 0;
 911 }
 912
 913 /*
 914  * Traverse through memblock structure and setup crash memory ranges. These
 915  * ranges will be used create PT_LOAD program headers in elfcore header.
 916  */
 917 static void fadump_setup_crash_memory_ranges(void)
 918 {
 919         struct memblock_region *reg;
 920         unsigned long long start, end;
 921
 922         pr_debug("Setup crash memory ranges.\n");
 923         crash_mem_ranges = 0;
 924         /*
 925          * add the first memory chunk (RMA_START through boot_memory_size) as
 926          * a separate memory chunk. The reason is, at the time crash firmware
 927          * will move the content of this memory chunk to different location
 928          * specified during fadump registration. We need to create a separate
 929          * program header for this chunk with the correct offset.
 930          */
 931         fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 932
 933         for_each_memblock(memory, reg) {
 934                 start = (unsigned long long)reg->base;
 935                 end = start + (unsigned long long)reg->size;
 936
 937                 /*
 938                  * skip the first memory chunk that is already added (RMA_START
 939                  * through boot_memory_size). This logic needs a relook if and
 940                  * when RMA_START changes to a non-zero value.
 941                  */
 942                 BUILD_BUG_ON(RMA_START != 0);
 943                 if (start < fw_dump.boot_memory_size) {
 944                         if (end > fw_dump.boot_memory_size)
 945                                 start = fw_dump.boot_memory_size;
 946                         else
 947                                 continue;
 948                 }
 949
 950                 /* add this range excluding the reserved dump area. */
 951                 fadump_exclude_reserved_area(start, end);
 952         }
 953 }
 954
 955 /*
 956  * If the given physical address falls within the boot memory region then
 957  * return the relocated address that points to the dump region reserved
 958  * for saving initial boot memory contents.
 959  */
 960 static inline unsigned long fadump_relocate(unsigned long paddr)
 961 {
 962         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 963                 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
 964         else
 965                 return paddr;
 966 }
 967
 968 static int fadump_create_elfcore_headers(char *bufp)
 969 {
 970         struct elfhdr *elf;
 971         struct elf_phdr *phdr;
 972         int i;
 973
 974         fadump_init_elfcore_header(bufp);
 975         elf = (struct elfhdr *)bufp;
 976         bufp += sizeof(struct elfhdr);
 977
 978         /*
 979          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
 980          * will be populated during second kernel boot after crash. Hence
 981          * this PT_NOTE will always be the first elf note.
 982          *
 983          * NOTE: Any new ELF note addition should be placed after this note.
 984          */
 985         phdr = (struct elf_phdr *)bufp;
 986         bufp += sizeof(struct elf_phdr);
 987         phdr->p_type = PT_NOTE;
 988         phdr->p_flags = 0;
 989         phdr->p_vaddr = 0;
 990         phdr->p_align = 0;
 991
 992         phdr->p_offset = 0;
 993         phdr->p_paddr = 0;
 994         phdr->p_filesz = 0;
 995         phdr->p_memsz = 0;
 996
 997         (elf->e_phnum)++;
 998
 999         /* setup ELF PT_NOTE for vmcoreinfo */
1000         phdr = (struct elf_phdr *)bufp;
1001         bufp += sizeof(struct elf_phdr);
1002         phdr->p_type    = PT_NOTE;
1003         phdr->p_flags   = 0;
1004         phdr->p_vaddr   = 0;
1005         phdr->p_align   = 0;
1006
1007         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
1008         phdr->p_offset  = phdr->p_paddr;
1009         phdr->p_memsz   = phdr->p_filesz = VMCOREINFO_NOTE_SIZE;
1010
1011         /* Increment number of program headers. */
1012         (elf->e_phnum)++;
1013
1014         /* setup PT_LOAD sections. */
1015
1016         for (i = 0; i < crash_mem_ranges; i++) {
1017                 unsigned long long mbase, msize;
1018                 mbase = crash_memory_ranges[i].base;
1019                 msize = crash_memory_ranges[i].size;
1020
1021                 if (!msize)
1022                         continue;
1023
1024                 phdr = (struct elf_phdr *)bufp;
1025                 bufp += sizeof(struct elf_phdr);
1026                 phdr->p_type    = PT_LOAD;
1027                 phdr->p_flags   = PF_R|PF_W|PF_X;
1028                 phdr->p_offset  = mbase;
1029
1030                 if (mbase == RMA_START) {
1031                         /*
1032                          * The entire RMA region will be moved by firmware
1033                          * to the specified destination_address. Hence set
1034                          * the correct offset.
1035                          */
1036                         phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
1037                 }
1038
1039                 phdr->p_paddr = mbase;
1040                 phdr->p_vaddr = (unsigned long)__va(mbase);
1041                 phdr->p_filesz = msize;
1042                 phdr->p_memsz = msize;
1043                 phdr->p_align = 0;
1044
1045                 /* Increment number of program headers. */
1046                 (elf->e_phnum)++;
1047         }
1048         return 0;
1049 }
1050
1051 static unsigned long init_fadump_header(unsigned long addr)
1052 {
1053         struct fadump_crash_info_header *fdh;
1054
1055         if (!addr)
1056                 return 0;
1057
1058         fw_dump.fadumphdr_addr = addr;
1059         fdh = __va(addr);
1060         addr += sizeof(struct fadump_crash_info_header);
1061
1062         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1063         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1064         fdh->elfcorehdr_addr = addr;
1065         /* We will set the crashing cpu id in crash_fadump() during crash. */
1066         fdh->crashing_cpu = CPU_UNKNOWN;
1067
1068         return addr;
1069 }
1070
1071 static int register_fadump(void)
1072 {
1073         unsigned long addr;
1074         void *vaddr;
1075
1076         /*
1077          * If no memory is reserved then we can not register for firmware-
1078          * assisted dump.
1079          */
1080         if (!fw_dump.reserve_dump_area_size)
1081                 return -ENODEV;
1082
1083         fadump_setup_crash_memory_ranges();
1084
1085         addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1086         /* Initialize fadump crash info header. */
1087         addr = init_fadump_header(addr);
1088         vaddr = __va(addr);
1089
1090         pr_debug("Creating ELF core headers at %#016lx\n", addr);
1091         fadump_create_elfcore_headers(vaddr);
1092
1093         /* register the future kernel dump with firmware. */
1094         return register_fw_dump(&fdm);
1095 }
1096
1097 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1098 {
1099         int rc = 0;
1100         unsigned int wait_time;
1101
1102         pr_debug("Un-register firmware-assisted dump\n");
1103
1104         /* TODO: Add upper time limit for the delay */
1105         do {
1106                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1107                         FADUMP_UNREGISTER, fdm,
1108                         sizeof(struct fadump_mem_struct));
1109
1110                 wait_time = rtas_busy_delay_time(rc);
1111                 if (wait_time)
1112                         mdelay(wait_time);
1113         } while (wait_time);
1114
1115         if (rc) {
1116                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1117                         " unexpected error(%d).\n", rc);
1118                 return rc;
1119         }
1120         fw_dump.dump_registered = 0;
1121         return 0;
1122 }
1123
1124 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1125 {
1126         int rc = 0;
1127         unsigned int wait_time;
1128
1129         pr_debug("Invalidating firmware-assisted dump registration\n");
1130
1131         /* TODO: Add upper time limit for the delay */
1132         do {
1133                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1134                         FADUMP_INVALIDATE, fdm,
1135                         sizeof(struct fadump_mem_struct));
1136
1137                 wait_time = rtas_busy_delay_time(rc);
1138                 if (wait_time)
1139                         mdelay(wait_time);
1140         } while (wait_time);
1141
1142         if (rc) {
1143                 pr_err("Failed to invalidate firmware-assisted dump registration. Unexpected error (%d).\n", rc);
1144                 return rc;
1145         }
1146         fw_dump.dump_active = 0;
1147         fdm_active = NULL;
1148         return 0;
1149 }
1150
1151 void fadump_cleanup(void)
1152 {
1153         /* Invalidate the registration only if dump is active. */
1154         if (fw_dump.dump_active) {
1155                 init_fadump_mem_struct(&fdm,
1156                         be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1157                 fadump_invalidate_dump(&fdm);
1158         }
1159 }
1160
1161 static void fadump_free_reserved_memory(unsigned long start_pfn,
1162                                         unsigned long end_pfn)
1163 {
1164         unsigned long pfn;
1165         unsigned long time_limit = jiffies + HZ;
1166
1167         pr_info("freeing reserved memory (0x%llx - 0x%llx)\n",
1168                 PFN_PHYS(start_pfn), PFN_PHYS(end_pfn));
1169
1170         for (pfn = start_pfn; pfn < end_pfn; pfn++) {
1171                 free_reserved_page(pfn_to_page(pfn));
1172
1173                 if (time_after(jiffies, time_limit)) {
1174                         cond_resched();
1175                         time_limit = jiffies + HZ;
1176                 }
1177         }
1178 }
1179
1180 /*
1181  * Skip memory holes and free memory that was actually reserved.
1182  */
1183 static void fadump_release_reserved_area(unsigned long start, unsigned long end)
1184 {
1185         struct memblock_region *reg;
1186         unsigned long tstart, tend;
1187         unsigned long start_pfn = PHYS_PFN(start);
1188         unsigned long end_pfn = PHYS_PFN(end);
1189
1190         for_each_memblock(memory, reg) {
1191                 tstart = max(start_pfn, memblock_region_memory_base_pfn(reg));
1192                 tend = min(end_pfn, memblock_region_memory_end_pfn(reg));
1193                 if (tstart < tend) {
1194                         fadump_free_reserved_memory(tstart, tend);
1195
1196                         if (tend == end_pfn)
1197                                 break;
1198
1199                         start_pfn = tend + 1;
1200                 }
1201         }
1202 }
1203
1204 /*
1205  * Release the memory that was reserved in early boot to preserve the memory
1206  * contents. The released memory will be available for general use.
1207  */
1208 static void fadump_release_memory(unsigned long begin, unsigned long end)
1209 {
1210         unsigned long ra_start, ra_end;
1211
1212         ra_start = fw_dump.reserve_dump_area_start;
1213         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1214
1215         /*
1216          * exclude the dump reserve area. Will reuse it for next
1217          * fadump registration.
1218          */
1219         if (begin < ra_end && end > ra_start) {
1220                 if (begin < ra_start)
1221                         fadump_release_reserved_area(begin, ra_start);
1222                 if (end > ra_end)
1223                         fadump_release_reserved_area(ra_end, end);
1224         } else
1225                 fadump_release_reserved_area(begin, end);
1226 }
1227
1228 static void fadump_invalidate_release_mem(void)
1229 {
1230         unsigned long reserved_area_start, reserved_area_end;
1231         unsigned long destination_address;
1232
1233         mutex_lock(&fadump_mutex);
1234         if (!fw_dump.dump_active) {
1235                 mutex_unlock(&fadump_mutex);
1236                 return;
1237         }
1238
1239         destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1240         fadump_cleanup();
1241         mutex_unlock(&fadump_mutex);
1242
1243         /*
1244          * Save the current reserved memory bounds we will require them
1245          * later for releasing the memory for general use.
1246          */
1247         reserved_area_start = fw_dump.reserve_dump_area_start;
1248         reserved_area_end = reserved_area_start +
1249                         fw_dump.reserve_dump_area_size;
1250         /*
1251          * Setup reserve_dump_area_start and its size so that we can
1252          * reuse this reserved memory for Re-registration.
1253          */
1254         fw_dump.reserve_dump_area_start = destination_address;
1255         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1256
1257         fadump_release_memory(reserved_area_start, reserved_area_end);
1258         if (fw_dump.cpu_notes_buf) {
1259                 fadump_cpu_notes_buf_free(
1260                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1261                                 fw_dump.cpu_notes_buf_size);
1262                 fw_dump.cpu_notes_buf = 0;
1263                 fw_dump.cpu_notes_buf_size = 0;
1264         }
1265         /* Initialize the kernel dump memory structure for FAD registration. */
1266         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1267 }
1268
1269 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1270                                         struct kobj_attribute *attr,
1271                                         const char *buf, size_t count)
1272 {
1273         int input = -1;
1274
1275         if (!fw_dump.dump_active)
1276                 return -EPERM;
1277
1278         if (kstrtoint(buf, 0, &input))
1279                 return -EINVAL;
1280
1281         if (input == 1) {
1282                 /*
1283                  * Take away the '/proc/vmcore'. We are releasing the dump
1284                  * memory, hence it will not be valid anymore.
1285                  */
1286 #ifdef CONFIG_PROC_VMCORE
1287                 vmcore_cleanup();
1288 #endif
1289                 fadump_invalidate_release_mem();
1290
1291         } else
1292                 return -EINVAL;
1293         return count;
1294 }
1295
1296 static ssize_t fadump_enabled_show(struct kobject *kobj,
1297                                         struct kobj_attribute *attr,
1298                                         char *buf)
1299 {
1300         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1301 }
1302
1303 static ssize_t fadump_register_show(struct kobject *kobj,
1304                                         struct kobj_attribute *attr,
1305                                         char *buf)
1306 {
1307         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1308 }
1309
1310 static ssize_t fadump_register_store(struct kobject *kobj,
1311                                         struct kobj_attribute *attr,
1312                                         const char *buf, size_t count)
1313 {
1314         int ret = 0;
1315         int input = -1;
1316
1317         if (!fw_dump.fadump_enabled || fdm_active)
1318                 return -EPERM;
1319
1320         if (kstrtoint(buf, 0, &input))
1321                 return -EINVAL;
1322
1323         mutex_lock(&fadump_mutex);
1324
1325         switch (input) {
1326         case 0:
1327                 if (fw_dump.dump_registered == 0) {
1328                         goto unlock_out;
1329                 }
1330                 /* Un-register Firmware-assisted dump */
1331                 fadump_unregister_dump(&fdm);
1332                 break;
1333         case 1:
1334                 if (fw_dump.dump_registered == 1) {
1335                         ret = -EEXIST;
1336                         goto unlock_out;
1337                 }
1338                 /* Register Firmware-assisted dump */
1339                 ret = register_fadump();
1340                 break;
1341         default:
1342                 ret = -EINVAL;
1343                 break;
1344         }
1345
1346 unlock_out:
1347         mutex_unlock(&fadump_mutex);
1348         return ret < 0 ? ret : count;
1349 }
1350
1351 static int fadump_region_show(struct seq_file *m, void *private)
1352 {
1353         const struct fadump_mem_struct *fdm_ptr;
1354
1355         if (!fw_dump.fadump_enabled)
1356                 return 0;
1357
1358         mutex_lock(&fadump_mutex);
1359         if (fdm_active)
1360                 fdm_ptr = fdm_active;
1361         else {
1362                 mutex_unlock(&fadump_mutex);
1363                 fdm_ptr = &fdm;
1364         }
1365
1366         seq_printf(m,
1367                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1368                         "Dumped: %#llx\n",
1369                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1370                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1371                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1372                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1373                         be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1374         seq_printf(m,
1375                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1376                         "Dumped: %#llx\n",
1377                         be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1378                         be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1379                         be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1380                         be64_to_cpu(fdm_ptr->hpte_region.source_len),
1381                         be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1382         seq_printf(m,
1383                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1384                         "Dumped: %#llx\n",
1385                         be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1386                         be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1387                         be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1388                         be64_to_cpu(fdm_ptr->rmr_region.source_len),
1389                         be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1390
1391         if (!fdm_active ||
1392                 (fw_dump.reserve_dump_area_start ==
1393                 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1394                 goto out;
1395
1396         /* Dump is active. Show reserved memory region. */
1397         seq_printf(m,
1398                         "    : [%#016llx-%#016llx] %#llx bytes, "
1399                         "Dumped: %#llx\n",
1400                         (unsigned long long)fw_dump.reserve_dump_area_start,
1401                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1402                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1403                         fw_dump.reserve_dump_area_start,
1404                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1405                         fw_dump.reserve_dump_area_start);
1406 out:
1407         if (fdm_active)
1408                 mutex_unlock(&fadump_mutex);
1409         return 0;
1410 }
1411
1412 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1413                                                 0200, NULL,
1414                                                 fadump_release_memory_store);
1415 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1416                                                 0444, fadump_enabled_show,
1417                                                 NULL);
1418 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1419                                                 0644, fadump_register_show,
1420                                                 fadump_register_store);
1421
1422 static int fadump_region_open(struct inode *inode, struct file *file)
1423 {
1424         return single_open(file, fadump_region_show, inode->i_private);
1425 }
1426
1427 static const struct file_operations fadump_region_fops = {
1428         .open    = fadump_region_open,
1429         .read    = seq_read,
1430         .llseek  = seq_lseek,
1431         .release = single_release,
1432 };
1433
1434 static void fadump_init_files(void)
1435 {
1436         struct dentry *debugfs_file;
1437         int rc = 0;
1438
1439         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1440         if (rc)
1441                 printk(KERN_ERR "fadump: unable to create sysfs file"
1442                         " fadump_enabled (%d)\n", rc);
1443
1444         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1445         if (rc)
1446                 printk(KERN_ERR "fadump: unable to create sysfs file"
1447                         " fadump_registered (%d)\n", rc);
1448
1449         debugfs_file = debugfs_create_file("fadump_region", 0444,
1450                                         powerpc_debugfs_root, NULL,
1451                                         &fadump_region_fops);
1452         if (!debugfs_file)
1453                 printk(KERN_ERR "fadump: unable to create debugfs file"
1454                                 " fadump_region\n");
1455
1456         if (fw_dump.dump_active) {
1457                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1458                 if (rc)
1459                         printk(KERN_ERR "fadump: unable to create sysfs file"
1460                                 " fadump_release_mem (%d)\n", rc);
1461         }
1462         return;
1463 }
1464
1465 /*
1466  * Prepare for firmware-assisted dump.
1467  */
1468 int __init setup_fadump(void)
1469 {
1470         if (!fw_dump.fadump_enabled)
1471                 return 0;
1472
1473         if (!fw_dump.fadump_supported) {
1474                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1475                         " this hardware\n");
1476                 return 0;
1477         }
1478
1479         fadump_show_config();
1480         /*
1481          * If dump data is available then see if it is valid and prepare for
1482          * saving it to the disk.
1483          */
1484         if (fw_dump.dump_active) {
1485                 /*
1486                  * if dump process fails then invalidate the registration
1487                  * and release memory before proceeding for re-registration.
1488                  */
1489                 if (process_fadump(fdm_active) < 0)
1490                         fadump_invalidate_release_mem();
1491         }
1492         /* Initialize the kernel dump memory structure for FAD registration. */
1493         else if (fw_dump.reserve_dump_area_size)
1494                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1495         fadump_init_files();
1496
1497         return 1;
1498 }
1499 subsys_initcall(setup_fadump);