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