arch/powerpc/kernel/fadump.c

   1 /*
   2  * Firmware Assisted dump: A robust mechanism to get reliable kernel crash
   3  * dump with assistance from firmware. This approach does not use kexec,
   4  * instead firmware assists in booting the kdump kernel while preserving
   5  * memory contents. The most of the code implementation has been adapted
   6  * from phyp assisted dump implementation written by Linas Vepstas and
   7  * Manish Ahuja
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22  *
  23  * Copyright 2011 IBM Corporation
  24  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
  25  */
  26
  27 #undef DEBUG
  28 #define pr_fmt(fmt) "fadump: " fmt
  29
  30 #include <linux/string.h>
  31 #include <linux/memblock.h>
  32 #include <linux/delay.h>
  33 #include <linux/debugfs.h>
  34 #include <linux/seq_file.h>
  35 #include <linux/crash_dump.h>
  36 #include <linux/kobject.h>
  37 #include <linux/sysfs.h>
  38 #include <linux/slab.h>
  39
  40 #include <asm/page.h>
  41 #include <asm/prom.h>
  42 #include <asm/rtas.h>
  43 #include <asm/fadump.h>
  44 #include <asm/debug.h>
  45 #include <asm/setup.h>
  46
  47 static struct fw_dump fw_dump;
  48 static struct fadump_mem_struct fdm;
  49 static const struct fadump_mem_struct *fdm_active;
  50
  51 static DEFINE_MUTEX(fadump_mutex);
  52 struct fad_crash_memory_ranges *crash_memory_ranges;
  53 int crash_memory_ranges_size;
  54 int crash_mem_ranges;
  55 int max_crash_mem_ranges;
  56
  57 /* Scan the Firmware Assisted dump configuration details. */
  58 int __init early_init_dt_scan_fw_dump(unsigned long node,
  59                         const char *uname, int depth, void *data)
  60 {
  61         const __be32 *sections;
  62         int i, num_sections;
  63         int size;
  64         const int *token;
  65
  66         if (depth != 1 || strcmp(uname, "rtas") != 0)
  67                 return 0;
  68
  69         /*
  70          * Check if Firmware Assisted dump is supported. if yes, check
  71          * if dump has been initiated on last reboot.
  72          */
  73         token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
  74         if (!token)
  75                 return 1;
  76
  77         fw_dump.fadump_supported = 1;
  78         fw_dump.ibm_configure_kernel_dump = *token;
  79
  80         /*
  81          * The 'ibm,kernel-dump' rtas node is present only if there is
  82          * dump data waiting for us.
  83          */
  84         fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
  85         if (fdm_active)
  86                 fw_dump.dump_active = 1;
  87
  88         /* Get the sizes required to store dump data for the firmware provided
  89          * dump sections.
  90          * For each dump section type supported, a 32bit cell which defines
  91          * the ID of a supported section followed by two 32 bit cells which
  92          * gives teh size of the section in bytes.
  93          */
  94         sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
  95                                         &size);
  96
  97         if (!sections)
  98                 return 1;
  99
 100         num_sections = size / (3 * sizeof(u32));
 101
 102         for (i = 0; i < num_sections; i++, sections += 3) {
 103                 u32 type = (u32)of_read_number(sections, 1);
 104
 105                 switch (type) {
 106                 case FADUMP_CPU_STATE_DATA:
 107                         fw_dump.cpu_state_data_size =
 108                                         of_read_ulong(&sections[1], 2);
 109                         break;
 110                 case FADUMP_HPTE_REGION:
 111                         fw_dump.hpte_region_size =
 112                                         of_read_ulong(&sections[1], 2);
 113                         break;
 114                 }
 115         }
 116
 117         return 1;
 118 }
 119
 120 int is_fadump_active(void)
 121 {
 122         return fw_dump.dump_active;
 123 }
 124
 125 /* Print firmware assisted dump configurations for debugging purpose. */
 126 static void fadump_show_config(void)
 127 {
 128         pr_debug("Support for firmware-assisted dump (fadump): %s\n",
 129                         (fw_dump.fadump_supported ? "present" : "no support"));
 130
 131         if (!fw_dump.fadump_supported)
 132                 return;
 133
 134         pr_debug("Fadump enabled    : %s\n",
 135                                 (fw_dump.fadump_enabled ? "yes" : "no"));
 136         pr_debug("Dump Active       : %s\n",
 137                                 (fw_dump.dump_active ? "yes" : "no"));
 138         pr_debug("Dump section sizes:\n");
 139         pr_debug("    CPU state data size: %lx\n", fw_dump.cpu_state_data_size);
 140         pr_debug("    HPTE region size   : %lx\n", fw_dump.hpte_region_size);
 141         pr_debug("Boot memory size  : %lx\n", fw_dump.boot_memory_size);
 142 }
 143
 144 static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
 145                                 unsigned long addr)
 146 {
 147         if (!fdm)
 148                 return 0;
 149
 150         memset(fdm, 0, sizeof(struct fadump_mem_struct));
 151         addr = addr & PAGE_MASK;
 152
 153         fdm->header.dump_format_version = 0x00000001;
 154         fdm->header.dump_num_sections = 3;
 155         fdm->header.dump_status_flag = 0;
 156         fdm->header.offset_first_dump_section =
 157                 (u32)offsetof(struct fadump_mem_struct, cpu_state_data);
 158
 159         /*
 160          * Fields for disk dump option.
 161          * We are not using disk dump option, hence set these fields to 0.
 162          */
 163         fdm->header.dd_block_size = 0;
 164         fdm->header.dd_block_offset = 0;
 165         fdm->header.dd_num_blocks = 0;
 166         fdm->header.dd_offset_disk_path = 0;
 167
 168         /* set 0 to disable an automatic dump-reboot. */
 169         fdm->header.max_time_auto = 0;
 170
 171         /* Kernel dump sections */
 172         /* cpu state data section. */
 173         fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG;
 174         fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA;
 175         fdm->cpu_state_data.source_address = 0;
 176         fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size;
 177         fdm->cpu_state_data.destination_address = addr;
 178         addr += fw_dump.cpu_state_data_size;
 179
 180         /* hpte region section */
 181         fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG;
 182         fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION;
 183         fdm->hpte_region.source_address = 0;
 184         fdm->hpte_region.source_len = fw_dump.hpte_region_size;
 185         fdm->hpte_region.destination_address = addr;
 186         addr += fw_dump.hpte_region_size;
 187
 188         /* RMA region section */
 189         fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG;
 190         fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION;
 191         fdm->rmr_region.source_address = RMA_START;
 192         fdm->rmr_region.source_len = fw_dump.boot_memory_size;
 193         fdm->rmr_region.destination_address = addr;
 194         addr += fw_dump.boot_memory_size;
 195
 196         return addr;
 197 }
 198
 199 /**
 200  * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM
 201  *
 202  * Function to find the largest memory size we need to reserve during early
 203  * boot process. This will be the size of the memory that is required for a
 204  * kernel to boot successfully.
 205  *
 206  * This function has been taken from phyp-assisted dump feature implementation.
 207  *
 208  * returns larger of 256MB or 5% rounded down to multiples of 256MB.
 209  *
 210  * TODO: Come up with better approach to find out more accurate memory size
 211  * that is required for a kernel to boot successfully.
 212  *
 213  */
 214 static inline unsigned long fadump_calculate_reserve_size(void)
 215 {
 216         unsigned long size;
 217
 218         /*
 219          * Check if the size is specified through fadump_reserve_mem= cmdline
 220          * option. If yes, then use that.
 221          */
 222         if (fw_dump.reserve_bootvar)
 223                 return fw_dump.reserve_bootvar;
 224
 225         /* divide by 20 to get 5% of value */
 226         size = memblock_end_of_DRAM() / 20;
 227
 228         /* round it down in multiples of 256 */
 229         size = size & ~0x0FFFFFFFUL;
 230
 231         /* Truncate to memory_limit. We don't want to over reserve the memory.*/
 232         if (memory_limit && size > memory_limit)
 233                 size = memory_limit;
 234
 235         return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM);
 236 }
 237
 238 /*
 239  * Calculate the total memory size required to be reserved for
 240  * firmware-assisted dump registration.
 241  */
 242 static unsigned long get_fadump_area_size(void)
 243 {
 244         unsigned long size = 0;
 245
 246         size += fw_dump.cpu_state_data_size;
 247         size += fw_dump.hpte_region_size;
 248         size += fw_dump.boot_memory_size;
 249         size += sizeof(struct fadump_crash_info_header);
 250         size += sizeof(struct elfhdr); /* ELF core header.*/
 251         size += sizeof(struct elf_phdr); /* place holder for cpu notes */
 252         /* Program headers for crash memory regions. */
 253         size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
 254
 255         size = PAGE_ALIGN(size);
 256         return size;
 257 }
 258
 259 int __init fadump_reserve_mem(void)
 260 {
 261         unsigned long base, size, memory_boundary;
 262
 263         if (!fw_dump.fadump_enabled)
 264                 return 0;
 265
 266         if (!fw_dump.fadump_supported) {
 267                 printk(KERN_INFO "Firmware-assisted dump is not supported on"
 268                                 " this hardware\n");
 269                 fw_dump.fadump_enabled = 0;
 270                 return 0;
 271         }
 272         /*
 273          * Initialize boot memory size
 274          * If dump is active then we have already calculated the size during
 275          * first kernel.
 276          */
 277         if (fdm_active)
 278                 fw_dump.boot_memory_size = fdm_active->rmr_region.source_len;
 279         else
 280                 fw_dump.boot_memory_size = fadump_calculate_reserve_size();
 281
 282         /*
 283          * Calculate the memory boundary.
 284          * If memory_limit is less than actual memory boundary then reserve
 285          * the memory for fadump beyond the memory_limit and adjust the
 286          * memory_limit accordingly, so that the running kernel can run with
 287          * specified memory_limit.
 288          */
 289         if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
 290                 size = get_fadump_area_size();
 291                 if ((memory_limit + size) < memblock_end_of_DRAM())
 292                         memory_limit += size;
 293                 else
 294                         memory_limit = memblock_end_of_DRAM();
 295                 printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
 296                                 " dump, now %#016llx\n", memory_limit);
 297         }
 298         if (memory_limit)
 299                 memory_boundary = memory_limit;
 300         else
 301                 memory_boundary = memblock_end_of_DRAM();
 302
 303         if (fw_dump.dump_active) {
 304                 printk(KERN_INFO "Firmware-assisted dump is active.\n");
 305                 /*
 306                  * If last boot has crashed then reserve all the memory
 307                  * above boot_memory_size so that we don't touch it until
 308                  * dump is written to disk by userspace tool. This memory
 309                  * will be released for general use once the dump is saved.
 310                  */
 311                 base = fw_dump.boot_memory_size;
 312                 size = memory_boundary - base;
 313                 memblock_reserve(base, size);
 314                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
 315                                 "for saving crash dump\n",
 316                                 (unsigned long)(size >> 20),
 317                                 (unsigned long)(base >> 20));
 318
 319                 fw_dump.fadumphdr_addr =
 320                                 fdm_active->rmr_region.destination_address +
 321                                 fdm_active->rmr_region.source_len;
 322                 pr_debug("fadumphdr_addr = %p\n",
 323                                 (void *) fw_dump.fadumphdr_addr);
 324         } else {
 325                 /* Reserve the memory at the top of memory. */
 326                 size = get_fadump_area_size();
 327                 base = memory_boundary - size;
 328                 memblock_reserve(base, size);
 329                 printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
 330                                 "for firmware-assisted dump\n",
 331                                 (unsigned long)(size >> 20),
 332                                 (unsigned long)(base >> 20));
 333         }
 334         fw_dump.reserve_dump_area_start = base;
 335         fw_dump.reserve_dump_area_size = size;
 336         return 1;
 337 }
 338
 339 /* Look for fadump= cmdline option. */
 340 static int __init early_fadump_param(char *p)
 341 {
 342         if (!p)
 343                 return 1;
 344
 345         if (strncmp(p, "on", 2) == 0)
 346                 fw_dump.fadump_enabled = 1;
 347         else if (strncmp(p, "off", 3) == 0)
 348                 fw_dump.fadump_enabled = 0;
 349
 350         return 0;
 351 }
 352 early_param("fadump", early_fadump_param);
 353
 354 /* Look for fadump_reserve_mem= cmdline option */
 355 static int __init early_fadump_reserve_mem(char *p)
 356 {
 357         if (p)
 358                 fw_dump.reserve_bootvar = memparse(p, &p);
 359         return 0;
 360 }
 361 early_param("fadump_reserve_mem", early_fadump_reserve_mem);
 362
 363 static void register_fw_dump(struct fadump_mem_struct *fdm)
 364 {
 365         int rc;
 366         unsigned int wait_time;
 367
 368         pr_debug("Registering for firmware-assisted kernel dump...\n");
 369
 370         /* TODO: Add upper time limit for the delay */
 371         do {
 372                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
 373                         FADUMP_REGISTER, fdm,
 374                         sizeof(struct fadump_mem_struct));
 375
 376                 wait_time = rtas_busy_delay_time(rc);
 377                 if (wait_time)
 378                         mdelay(wait_time);
 379
 380         } while (wait_time);
 381
 382         switch (rc) {
 383         case -1:
 384                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 385                         " dump. Hardware Error(%d).\n", rc);
 386                 break;
 387         case -3:
 388                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 389                         " dump. Parameter Error(%d).\n", rc);
 390                 break;
 391         case -9:
 392                 printk(KERN_ERR "firmware-assisted kernel dump is already "
 393                         " registered.");
 394                 fw_dump.dump_registered = 1;
 395                 break;
 396         case 0:
 397                 printk(KERN_INFO "firmware-assisted kernel dump registration"
 398                         " is successful\n");
 399                 fw_dump.dump_registered = 1;
 400                 break;
 401         }
 402 }
 403
 404 void crash_fadump(struct pt_regs *regs, const char *str)
 405 {
 406         struct fadump_crash_info_header *fdh = NULL;
 407
 408         if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
 409                 return;
 410
 411         fdh = __va(fw_dump.fadumphdr_addr);
 412         crashing_cpu = smp_processor_id();
 413         fdh->crashing_cpu = crashing_cpu;
 414         crash_save_vmcoreinfo();
 415
 416         if (regs)
 417                 fdh->regs = *regs;
 418         else
 419                 ppc_save_regs(&fdh->regs);
 420
 421         fdh->cpu_online_mask = *cpu_online_mask;
 422
 423         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
 424         rtas_os_term((char *)str);
 425 }
 426
 427 #define GPR_MASK        0xffffff0000000000
 428 static inline int fadump_gpr_index(u64 id)
 429 {
 430         int i = -1;
 431         char str[3];
 432
 433         if ((id & GPR_MASK) == REG_ID("GPR")) {
 434                 /* get the digits at the end */
 435                 id &= ~GPR_MASK;
 436                 id >>= 24;
 437                 str[2] = '\0';
 438                 str[1] = id & 0xff;
 439                 str[0] = (id >> 8) & 0xff;
 440                 sscanf(str, "%d", &i);
 441                 if (i > 31)
 442                         i = -1;
 443         }
 444         return i;
 445 }
 446
 447 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
 448                                                                 u64 reg_val)
 449 {
 450         int i;
 451
 452         i = fadump_gpr_index(reg_id);
 453         if (i >= 0)
 454                 regs->gpr[i] = (unsigned long)reg_val;
 455         else if (reg_id == REG_ID("NIA"))
 456                 regs->nip = (unsigned long)reg_val;
 457         else if (reg_id == REG_ID("MSR"))
 458                 regs->msr = (unsigned long)reg_val;
 459         else if (reg_id == REG_ID("CTR"))
 460                 regs->ctr = (unsigned long)reg_val;
 461         else if (reg_id == REG_ID("LR"))
 462                 regs->link = (unsigned long)reg_val;
 463         else if (reg_id == REG_ID("XER"))
 464                 regs->xer = (unsigned long)reg_val;
 465         else if (reg_id == REG_ID("CR"))
 466                 regs->ccr = (unsigned long)reg_val;
 467         else if (reg_id == REG_ID("DAR"))
 468                 regs->dar = (unsigned long)reg_val;
 469         else if (reg_id == REG_ID("DSISR"))
 470                 regs->dsisr = (unsigned long)reg_val;
 471 }
 472
 473 static struct fadump_reg_entry*
 474 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 475 {
 476         memset(regs, 0, sizeof(struct pt_regs));
 477
 478         while (reg_entry->reg_id != REG_ID("CPUEND")) {
 479                 fadump_set_regval(regs, reg_entry->reg_id,
 480                                         reg_entry->reg_value);
 481                 reg_entry++;
 482         }
 483         reg_entry++;
 484         return reg_entry;
 485 }
 486
 487 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
 488                                                 void *data, size_t data_len)
 489 {
 490         struct elf_note note;
 491
 492         note.n_namesz = strlen(name) + 1;
 493         note.n_descsz = data_len;
 494         note.n_type   = type;
 495         memcpy(buf, &note, sizeof(note));
 496         buf += (sizeof(note) + 3)/4;
 497         memcpy(buf, name, note.n_namesz);
 498         buf += (note.n_namesz + 3)/4;
 499         memcpy(buf, data, note.n_descsz);
 500         buf += (note.n_descsz + 3)/4;
 501
 502         return buf;
 503 }
 504
 505 static void fadump_final_note(u32 *buf)
 506 {
 507         struct elf_note note;
 508
 509         note.n_namesz = 0;
 510         note.n_descsz = 0;
 511         note.n_type   = 0;
 512         memcpy(buf, &note, sizeof(note));
 513 }
 514
 515 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 516 {
 517         struct elf_prstatus prstatus;
 518
 519         memset(&prstatus, 0, sizeof(prstatus));
 520         /*
 521          * FIXME: How do i get PID? Do I really need it?
 522          * prstatus.pr_pid = ????
 523          */
 524         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 525         buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
 526                                 &prstatus, sizeof(prstatus));
 527         return buf;
 528 }
 529
 530 static void fadump_update_elfcore_header(char *bufp)
 531 {
 532         struct elfhdr *elf;
 533         struct elf_phdr *phdr;
 534
 535         elf = (struct elfhdr *)bufp;
 536         bufp += sizeof(struct elfhdr);
 537
 538         /* First note is a place holder for cpu notes info. */
 539         phdr = (struct elf_phdr *)bufp;
 540
 541         if (phdr->p_type == PT_NOTE) {
 542                 phdr->p_paddr = fw_dump.cpu_notes_buf;
 543                 phdr->p_offset  = phdr->p_paddr;
 544                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
 545                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
 546         }
 547         return;
 548 }
 549
 550 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
 551 {
 552         void *vaddr;
 553         struct page *page;
 554         unsigned long order, count, i;
 555
 556         order = get_order(size);
 557         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
 558         if (!vaddr)
 559                 return NULL;
 560
 561         count = 1 << order;
 562         page = virt_to_page(vaddr);
 563         for (i = 0; i < count; i++)
 564                 SetPageReserved(page + i);
 565         return vaddr;
 566 }
 567
 568 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
 569 {
 570         struct page *page;
 571         unsigned long order, count, i;
 572
 573         order = get_order(size);
 574         count = 1 << order;
 575         page = virt_to_page(vaddr);
 576         for (i = 0; i < count; i++)
 577                 ClearPageReserved(page + i);
 578         __free_pages(page, order);
 579 }
 580
 581 /*
 582  * Read CPU state dump data and convert it into ELF notes.
 583  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
 584  * used to access the data to allow for additional fields to be added without
 585  * affecting compatibility. Each list of registers for a CPU starts with
 586  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
 587  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
 588  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
 589  * of register value. For more details refer to PAPR document.
 590  *
 591  * Only for the crashing cpu we ignore the CPU dump data and get exact
 592  * state from fadump crash info structure populated by first kernel at the
 593  * time of crash.
 594  */
 595 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 596 {
 597         struct fadump_reg_save_area_header *reg_header;
 598         struct fadump_reg_entry *reg_entry;
 599         struct fadump_crash_info_header *fdh = NULL;
 600         void *vaddr;
 601         unsigned long addr;
 602         u32 num_cpus, *note_buf;
 603         struct pt_regs regs;
 604         int i, rc = 0, cpu = 0;
 605
 606         if (!fdm->cpu_state_data.bytes_dumped)
 607                 return -EINVAL;
 608
 609         addr = fdm->cpu_state_data.destination_address;
 610         vaddr = __va(addr);
 611
 612         reg_header = vaddr;
 613         if (reg_header->magic_number != REGSAVE_AREA_MAGIC) {
 614                 printk(KERN_ERR "Unable to read register save area.\n");
 615                 return -ENOENT;
 616         }
 617         pr_debug("--------CPU State Data------------\n");
 618         pr_debug("Magic Number: %llx\n", reg_header->magic_number);
 619         pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset);
 620
 621         vaddr += reg_header->num_cpu_offset;
 622         num_cpus = *((u32 *)(vaddr));
 623         pr_debug("NumCpus     : %u\n", num_cpus);
 624         vaddr += sizeof(u32);
 625         reg_entry = (struct fadump_reg_entry *)vaddr;
 626
 627         /* Allocate buffer to hold cpu crash notes. */
 628         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
 629         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
 630         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
 631         if (!note_buf) {
 632                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
 633                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
 634                 return -ENOMEM;
 635         }
 636         fw_dump.cpu_notes_buf = __pa(note_buf);
 637
 638         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
 639                         (num_cpus * sizeof(note_buf_t)), note_buf);
 640
 641         if (fw_dump.fadumphdr_addr)
 642                 fdh = __va(fw_dump.fadumphdr_addr);
 643
 644         for (i = 0; i < num_cpus; i++) {
 645                 if (reg_entry->reg_id != REG_ID("CPUSTRT")) {
 646                         printk(KERN_ERR "Unable to read CPU state data\n");
 647                         rc = -ENOENT;
 648                         goto error_out;
 649                 }
 650                 /* Lower 4 bytes of reg_value contains logical cpu id */
 651                 cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK;
 652                 if (fdh && !cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
 653                         SKIP_TO_NEXT_CPU(reg_entry);
 654                         continue;
 655                 }
 656                 pr_debug("Reading register data for cpu %d...\n", cpu);
 657                 if (fdh && fdh->crashing_cpu == cpu) {
 658                         regs = fdh->regs;
 659                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 660                         SKIP_TO_NEXT_CPU(reg_entry);
 661                 } else {
 662                         reg_entry++;
 663                         reg_entry = fadump_read_registers(reg_entry, &regs);
 664                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 665                 }
 666         }
 667         fadump_final_note(note_buf);
 668
 669         if (fdh) {
 670                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 671                                                         fdh->elfcorehdr_addr);
 672                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 673         }
 674         return 0;
 675
 676 error_out:
 677         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 678                                         fw_dump.cpu_notes_buf_size);
 679         fw_dump.cpu_notes_buf = 0;
 680         fw_dump.cpu_notes_buf_size = 0;
 681         return rc;
 682
 683 }
 684
 685 /*
 686  * Validate and process the dump data stored by firmware before exporting
 687  * it through '/proc/vmcore'.
 688  */
 689 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 690 {
 691         struct fadump_crash_info_header *fdh;
 692         int rc = 0;
 693
 694         if (!fdm_active || !fw_dump.fadumphdr_addr)
 695                 return -EINVAL;
 696
 697         /* Check if the dump data is valid. */
 698         if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) ||
 699                         (fdm_active->cpu_state_data.error_flags != 0) ||
 700                         (fdm_active->rmr_region.error_flags != 0)) {
 701                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 702                 return -EINVAL;
 703         }
 704         if ((fdm_active->rmr_region.bytes_dumped !=
 705                         fdm_active->rmr_region.source_len) ||
 706                         !fdm_active->cpu_state_data.bytes_dumped) {
 707                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 708                 return -EINVAL;
 709         }
 710
 711         /* Validate the fadump crash info header */
 712         fdh = __va(fw_dump.fadumphdr_addr);
 713         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 714                 printk(KERN_ERR "Crash info header is not valid.\n");
 715                 return -EINVAL;
 716         }
 717
 718         rc = fadump_build_cpu_notes(fdm_active);
 719         if (rc)
 720                 return rc;
 721
 722         /*
 723          * We are done validating dump info and elfcore header is now ready
 724          * to be exported. set elfcorehdr_addr so that vmcore module will
 725          * export the elfcore header through '/proc/vmcore'.
 726          */
 727         elfcorehdr_addr = fdh->elfcorehdr_addr;
 728
 729         return 0;
 730 }
 731
 732 static void free_crash_memory_ranges(void)
 733 {
 734         kfree(crash_memory_ranges);
 735         crash_memory_ranges = NULL;
 736         crash_memory_ranges_size = 0;
 737         max_crash_mem_ranges = 0;
 738 }
 739
 740 /*
 741  * Allocate or reallocate crash memory ranges array in incremental units
 742  * of PAGE_SIZE.
 743  */
 744 static int allocate_crash_memory_ranges(void)
 745 {
 746         struct fad_crash_memory_ranges *new_array;
 747         u64 new_size;
 748
 749         new_size = crash_memory_ranges_size + PAGE_SIZE;
 750         pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
 751                  new_size);
 752
 753         new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
 754         if (new_array == NULL) {
 755                 pr_err("Insufficient memory for setting up crash memory ranges\n");
 756                 free_crash_memory_ranges();
 757                 return -ENOMEM;
 758         }
 759
 760         crash_memory_ranges = new_array;
 761         crash_memory_ranges_size = new_size;
 762         max_crash_mem_ranges = (new_size /
 763                                 sizeof(struct fad_crash_memory_ranges));
 764         return 0;
 765 }
 766
 767 static inline int fadump_add_crash_memory(unsigned long long base,
 768                                           unsigned long long end)
 769 {
 770         if (base == end)
 771                 return 0;
 772
 773         if (crash_mem_ranges == max_crash_mem_ranges) {
 774                 int ret;
 775
 776                 ret = allocate_crash_memory_ranges();
 777                 if (ret)
 778                         return ret;
 779         }
 780
 781         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 782                 crash_mem_ranges, base, end - 1, (end - base));
 783         crash_memory_ranges[crash_mem_ranges].base = base;
 784         crash_memory_ranges[crash_mem_ranges].size = end - base;
 785         crash_mem_ranges++;
 786         return 0;
 787 }
 788
 789 static int fadump_exclude_reserved_area(unsigned long long start,
 790                                         unsigned long long end)
 791 {
 792         unsigned long long ra_start, ra_end;
 793         int ret = 0;
 794
 795         ra_start = fw_dump.reserve_dump_area_start;
 796         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 797
 798         if ((ra_start < end) && (ra_end > start)) {
 799                 if ((start < ra_start) && (end > ra_end)) {
 800                         ret = fadump_add_crash_memory(start, ra_start);
 801                         if (ret)
 802                                 return ret;
 803
 804                         ret = fadump_add_crash_memory(ra_end, end);
 805                 } else if (start < ra_start) {
 806                         ret = fadump_add_crash_memory(start, ra_start);
 807                 } else if (ra_end < end) {
 808                         ret = fadump_add_crash_memory(ra_end, end);
 809                 }
 810         } else
 811                 ret = fadump_add_crash_memory(start, end);
 812
 813         return ret;
 814 }
 815
 816 static int fadump_init_elfcore_header(char *bufp)
 817 {
 818         struct elfhdr *elf;
 819
 820         elf = (struct elfhdr *) bufp;
 821         bufp += sizeof(struct elfhdr);
 822         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 823         elf->e_ident[EI_CLASS] = ELF_CLASS;
 824         elf->e_ident[EI_DATA] = ELF_DATA;
 825         elf->e_ident[EI_VERSION] = EV_CURRENT;
 826         elf->e_ident[EI_OSABI] = ELF_OSABI;
 827         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 828         elf->e_type = ET_CORE;
 829         elf->e_machine = ELF_ARCH;
 830         elf->e_version = EV_CURRENT;
 831         elf->e_entry = 0;
 832         elf->e_phoff = sizeof(struct elfhdr);
 833         elf->e_shoff = 0;
 834         elf->e_flags = ELF_CORE_EFLAGS;
 835         elf->e_ehsize = sizeof(struct elfhdr);
 836         elf->e_phentsize = sizeof(struct elf_phdr);
 837         elf->e_phnum = 0;
 838         elf->e_shentsize = 0;
 839         elf->e_shnum = 0;
 840         elf->e_shstrndx = 0;
 841
 842         return 0;
 843 }
 844
 845 /*
 846  * Traverse through memblock structure and setup crash memory ranges. These
 847  * ranges will be used create PT_LOAD program headers in elfcore header.
 848  */
 849 static int fadump_setup_crash_memory_ranges(void)
 850 {
 851         struct memblock_region *reg;
 852         unsigned long long start, end;
 853         int ret;
 854
 855         pr_debug("Setup crash memory ranges.\n");
 856         crash_mem_ranges = 0;
 857         /*
 858          * add the first memory chunk (RMA_START through boot_memory_size) as
 859          * a separate memory chunk. The reason is, at the time crash firmware
 860          * will move the content of this memory chunk to different location
 861          * specified during fadump registration. We need to create a separate
 862          * program header for this chunk with the correct offset.
 863          */
 864         ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 865         if (ret)
 866                 return ret;
 867
 868         for_each_memblock(memory, reg) {
 869                 start = (unsigned long long)reg->base;
 870                 end = start + (unsigned long long)reg->size;
 871                 if (start == RMA_START && end >= fw_dump.boot_memory_size)
 872                         start = fw_dump.boot_memory_size;
 873
 874                 /* add this range excluding the reserved dump area. */
 875                 ret = fadump_exclude_reserved_area(start, end);
 876                 if (ret)
 877                         return ret;
 878         }
 879
 880         return 0;
 881 }
 882
 883 /*
 884  * If the given physical address falls within the boot memory region then
 885  * return the relocated address that points to the dump region reserved
 886  * for saving initial boot memory contents.
 887  */
 888 static inline unsigned long fadump_relocate(unsigned long paddr)
 889 {
 890         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 891                 return fdm.rmr_region.destination_address + paddr;
 892         else
 893                 return paddr;
 894 }
 895
 896 static int fadump_create_elfcore_headers(char *bufp)
 897 {
 898         struct elfhdr *elf;
 899         struct elf_phdr *phdr;
 900         int i;
 901
 902         fadump_init_elfcore_header(bufp);
 903         elf = (struct elfhdr *)bufp;
 904         bufp += sizeof(struct elfhdr);
 905
 906         /*
 907          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
 908          * will be populated during second kernel boot after crash. Hence
 909          * this PT_NOTE will always be the first elf note.
 910          *
 911          * NOTE: Any new ELF note addition should be placed after this note.
 912          */
 913         phdr = (struct elf_phdr *)bufp;
 914         bufp += sizeof(struct elf_phdr);
 915         phdr->p_type = PT_NOTE;
 916         phdr->p_flags = 0;
 917         phdr->p_vaddr = 0;
 918         phdr->p_align = 0;
 919
 920         phdr->p_offset = 0;
 921         phdr->p_paddr = 0;
 922         phdr->p_filesz = 0;
 923         phdr->p_memsz = 0;
 924
 925         (elf->e_phnum)++;
 926
 927         /* setup ELF PT_NOTE for vmcoreinfo */
 928         phdr = (struct elf_phdr *)bufp;
 929         bufp += sizeof(struct elf_phdr);
 930         phdr->p_type    = PT_NOTE;
 931         phdr->p_flags   = 0;
 932         phdr->p_vaddr   = 0;
 933         phdr->p_align   = 0;
 934
 935         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
 936         phdr->p_offset  = phdr->p_paddr;
 937         phdr->p_memsz   = vmcoreinfo_max_size;
 938         phdr->p_filesz  = vmcoreinfo_max_size;
 939
 940         /* Increment number of program headers. */
 941         (elf->e_phnum)++;
 942
 943         /* setup PT_LOAD sections. */
 944
 945         for (i = 0; i < crash_mem_ranges; i++) {
 946                 unsigned long long mbase, msize;
 947                 mbase = crash_memory_ranges[i].base;
 948                 msize = crash_memory_ranges[i].size;
 949
 950                 if (!msize)
 951                         continue;
 952
 953                 phdr = (struct elf_phdr *)bufp;
 954                 bufp += sizeof(struct elf_phdr);
 955                 phdr->p_type    = PT_LOAD;
 956                 phdr->p_flags   = PF_R|PF_W|PF_X;
 957                 phdr->p_offset  = mbase;
 958
 959                 if (mbase == RMA_START) {
 960                         /*
 961                          * The entire RMA region will be moved by firmware
 962                          * to the specified destination_address. Hence set
 963                          * the correct offset.
 964                          */
 965                         phdr->p_offset = fdm.rmr_region.destination_address;
 966                 }
 967
 968                 phdr->p_paddr = mbase;
 969                 phdr->p_vaddr = (unsigned long)__va(mbase);
 970                 phdr->p_filesz = msize;
 971                 phdr->p_memsz = msize;
 972                 phdr->p_align = 0;
 973
 974                 /* Increment number of program headers. */
 975                 (elf->e_phnum)++;
 976         }
 977         return 0;
 978 }
 979
 980 static unsigned long init_fadump_header(unsigned long addr)
 981 {
 982         struct fadump_crash_info_header *fdh;
 983
 984         if (!addr)
 985                 return 0;
 986
 987         fw_dump.fadumphdr_addr = addr;
 988         fdh = __va(addr);
 989         addr += sizeof(struct fadump_crash_info_header);
 990
 991         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
 992         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
 993         fdh->elfcorehdr_addr = addr;
 994         /* We will set the crashing cpu id in crash_fadump() during crash. */
 995         fdh->crashing_cpu = CPU_UNKNOWN;
 996
 997         return addr;
 998 }
 999
1000 static void register_fadump(void)
1001 {
1002         unsigned long addr;
1003         void *vaddr;
1004         int ret;
1005
1006         /*
1007          * If no memory is reserved then we can not register for firmware-
1008          * assisted dump.
1009          */
1010         if (!fw_dump.reserve_dump_area_size)
1011                 return;
1012
1013         ret = fadump_setup_crash_memory_ranges();
1014         if (ret)
1015                 return;
1016
1017         addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len;
1018         /* Initialize fadump crash info header. */
1019         addr = init_fadump_header(addr);
1020         vaddr = __va(addr);
1021
1022         pr_debug("Creating ELF core headers at %#016lx\n", addr);
1023         fadump_create_elfcore_headers(vaddr);
1024
1025         /* register the future kernel dump with firmware. */
1026         register_fw_dump(&fdm);
1027 }
1028
1029 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1030 {
1031         int rc = 0;
1032         unsigned int wait_time;
1033
1034         pr_debug("Un-register firmware-assisted dump\n");
1035
1036         /* TODO: Add upper time limit for the delay */
1037         do {
1038                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1039                         FADUMP_UNREGISTER, fdm,
1040                         sizeof(struct fadump_mem_struct));
1041
1042                 wait_time = rtas_busy_delay_time(rc);
1043                 if (wait_time)
1044                         mdelay(wait_time);
1045         } while (wait_time);
1046
1047         if (rc) {
1048                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1049                         " unexpected error(%d).\n", rc);
1050                 return rc;
1051         }
1052         fw_dump.dump_registered = 0;
1053         return 0;
1054 }
1055
1056 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1057 {
1058         int rc = 0;
1059         unsigned int wait_time;
1060
1061         pr_debug("Invalidating firmware-assisted dump registration\n");
1062
1063         /* TODO: Add upper time limit for the delay */
1064         do {
1065                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1066                         FADUMP_INVALIDATE, fdm,
1067                         sizeof(struct fadump_mem_struct));
1068
1069                 wait_time = rtas_busy_delay_time(rc);
1070                 if (wait_time)
1071                         mdelay(wait_time);
1072         } while (wait_time);
1073
1074         if (rc) {
1075                 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1076                         "rgistration. unexpected error(%d).\n", rc);
1077                 return rc;
1078         }
1079         fw_dump.dump_active = 0;
1080         fdm_active = NULL;
1081         return 0;
1082 }
1083
1084 void fadump_cleanup(void)
1085 {
1086         /* Invalidate the registration only if dump is active. */
1087         if (fw_dump.dump_active) {
1088                 init_fadump_mem_struct(&fdm,
1089                         fdm_active->cpu_state_data.destination_address);
1090                 fadump_invalidate_dump(&fdm);
1091         } else if (fw_dump.dump_registered) {
1092                 /* Un-register Firmware-assisted dump if it was registered. */
1093                 fadump_unregister_dump(&fdm);
1094                 free_crash_memory_ranges();
1095         }
1096 }
1097
1098 /*
1099  * Release the memory that was reserved in early boot to preserve the memory
1100  * contents. The released memory will be available for general use.
1101  */
1102 static void fadump_release_memory(unsigned long begin, unsigned long end)
1103 {
1104         unsigned long addr;
1105         unsigned long ra_start, ra_end;
1106
1107         ra_start = fw_dump.reserve_dump_area_start;
1108         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1109
1110         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1111                 /*
1112                  * exclude the dump reserve area. Will reuse it for next
1113                  * fadump registration.
1114                  */
1115                 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1116                         continue;
1117
1118                 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1119         }
1120 }
1121
1122 static void fadump_invalidate_release_mem(void)
1123 {
1124         unsigned long reserved_area_start, reserved_area_end;
1125         unsigned long destination_address;
1126
1127         mutex_lock(&fadump_mutex);
1128         if (!fw_dump.dump_active) {
1129                 mutex_unlock(&fadump_mutex);
1130                 return;
1131         }
1132
1133         destination_address = fdm_active->cpu_state_data.destination_address;
1134         fadump_cleanup();
1135         mutex_unlock(&fadump_mutex);
1136
1137         /*
1138          * Save the current reserved memory bounds we will require them
1139          * later for releasing the memory for general use.
1140          */
1141         reserved_area_start = fw_dump.reserve_dump_area_start;
1142         reserved_area_end = reserved_area_start +
1143                         fw_dump.reserve_dump_area_size;
1144         /*
1145          * Setup reserve_dump_area_start and its size so that we can
1146          * reuse this reserved memory for Re-registration.
1147          */
1148         fw_dump.reserve_dump_area_start = destination_address;
1149         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1150
1151         fadump_release_memory(reserved_area_start, reserved_area_end);
1152         if (fw_dump.cpu_notes_buf) {
1153                 fadump_cpu_notes_buf_free(
1154                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1155                                 fw_dump.cpu_notes_buf_size);
1156                 fw_dump.cpu_notes_buf = 0;
1157                 fw_dump.cpu_notes_buf_size = 0;
1158         }
1159         /* Initialize the kernel dump memory structure for FAD registration. */
1160         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1161 }
1162
1163 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1164                                         struct kobj_attribute *attr,
1165                                         const char *buf, size_t count)
1166 {
1167         if (!fw_dump.dump_active)
1168                 return -EPERM;
1169
1170         if (buf[0] == '1') {
1171                 /*
1172                  * Take away the '/proc/vmcore'. We are releasing the dump
1173                  * memory, hence it will not be valid anymore.
1174                  */
1175                 vmcore_cleanup();
1176                 fadump_invalidate_release_mem();
1177
1178         } else
1179                 return -EINVAL;
1180         return count;
1181 }
1182
1183 static ssize_t fadump_enabled_show(struct kobject *kobj,
1184                                         struct kobj_attribute *attr,
1185                                         char *buf)
1186 {
1187         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1188 }
1189
1190 static ssize_t fadump_register_show(struct kobject *kobj,
1191                                         struct kobj_attribute *attr,
1192                                         char *buf)
1193 {
1194         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1195 }
1196
1197 static ssize_t fadump_register_store(struct kobject *kobj,
1198                                         struct kobj_attribute *attr,
1199                                         const char *buf, size_t count)
1200 {
1201         int ret = 0;
1202
1203         if (!fw_dump.fadump_enabled || fdm_active)
1204                 return -EPERM;
1205
1206         mutex_lock(&fadump_mutex);
1207
1208         switch (buf[0]) {
1209         case '0':
1210                 if (fw_dump.dump_registered == 0) {
1211                         ret = -EINVAL;
1212                         goto unlock_out;
1213                 }
1214                 /* Un-register Firmware-assisted dump */
1215                 fadump_unregister_dump(&fdm);
1216                 break;
1217         case '1':
1218                 if (fw_dump.dump_registered == 1) {
1219                         ret = -EINVAL;
1220                         goto unlock_out;
1221                 }
1222                 /* Register Firmware-assisted dump */
1223                 register_fadump();
1224                 break;
1225         default:
1226                 ret = -EINVAL;
1227                 break;
1228         }
1229
1230 unlock_out:
1231         mutex_unlock(&fadump_mutex);
1232         return ret < 0 ? ret : count;
1233 }
1234
1235 static int fadump_region_show(struct seq_file *m, void *private)
1236 {
1237         const struct fadump_mem_struct *fdm_ptr;
1238
1239         if (!fw_dump.fadump_enabled)
1240                 return 0;
1241
1242         mutex_lock(&fadump_mutex);
1243         if (fdm_active)
1244                 fdm_ptr = fdm_active;
1245         else {
1246                 mutex_unlock(&fadump_mutex);
1247                 fdm_ptr = &fdm;
1248         }
1249
1250         seq_printf(m,
1251                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1252                         "Dumped: %#llx\n",
1253                         fdm_ptr->cpu_state_data.destination_address,
1254                         fdm_ptr->cpu_state_data.destination_address +
1255                         fdm_ptr->cpu_state_data.source_len - 1,
1256                         fdm_ptr->cpu_state_data.source_len,
1257                         fdm_ptr->cpu_state_data.bytes_dumped);
1258         seq_printf(m,
1259                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1260                         "Dumped: %#llx\n",
1261                         fdm_ptr->hpte_region.destination_address,
1262                         fdm_ptr->hpte_region.destination_address +
1263                         fdm_ptr->hpte_region.source_len - 1,
1264                         fdm_ptr->hpte_region.source_len,
1265                         fdm_ptr->hpte_region.bytes_dumped);
1266         seq_printf(m,
1267                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1268                         "Dumped: %#llx\n",
1269                         fdm_ptr->rmr_region.destination_address,
1270                         fdm_ptr->rmr_region.destination_address +
1271                         fdm_ptr->rmr_region.source_len - 1,
1272                         fdm_ptr->rmr_region.source_len,
1273                         fdm_ptr->rmr_region.bytes_dumped);
1274
1275         if (!fdm_active ||
1276                 (fw_dump.reserve_dump_area_start ==
1277                 fdm_ptr->cpu_state_data.destination_address))
1278                 goto out;
1279
1280         /* Dump is active. Show reserved memory region. */
1281         seq_printf(m,
1282                         "    : [%#016llx-%#016llx] %#llx bytes, "
1283                         "Dumped: %#llx\n",
1284                         (unsigned long long)fw_dump.reserve_dump_area_start,
1285                         fdm_ptr->cpu_state_data.destination_address - 1,
1286                         fdm_ptr->cpu_state_data.destination_address -
1287                         fw_dump.reserve_dump_area_start,
1288                         fdm_ptr->cpu_state_data.destination_address -
1289                         fw_dump.reserve_dump_area_start);
1290 out:
1291         if (fdm_active)
1292                 mutex_unlock(&fadump_mutex);
1293         return 0;
1294 }
1295
1296 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1297                                                 0200, NULL,
1298                                                 fadump_release_memory_store);
1299 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1300                                                 0444, fadump_enabled_show,
1301                                                 NULL);
1302 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1303                                                 0644, fadump_register_show,
1304                                                 fadump_register_store);
1305
1306 static int fadump_region_open(struct inode *inode, struct file *file)
1307 {
1308         return single_open(file, fadump_region_show, inode->i_private);
1309 }
1310
1311 static const struct file_operations fadump_region_fops = {
1312         .open    = fadump_region_open,
1313         .read    = seq_read,
1314         .llseek  = seq_lseek,
1315         .release = single_release,
1316 };
1317
1318 static void fadump_init_files(void)
1319 {
1320         struct dentry *debugfs_file;
1321         int rc = 0;
1322
1323         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1324         if (rc)
1325                 printk(KERN_ERR "fadump: unable to create sysfs file"
1326                         " fadump_enabled (%d)\n", rc);
1327
1328         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1329         if (rc)
1330                 printk(KERN_ERR "fadump: unable to create sysfs file"
1331                         " fadump_registered (%d)\n", rc);
1332
1333         debugfs_file = debugfs_create_file("fadump_region", 0444,
1334                                         powerpc_debugfs_root, NULL,
1335                                         &fadump_region_fops);
1336         if (!debugfs_file)
1337                 printk(KERN_ERR "fadump: unable to create debugfs file"
1338                                 " fadump_region\n");
1339
1340         if (fw_dump.dump_active) {
1341                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1342                 if (rc)
1343                         printk(KERN_ERR "fadump: unable to create sysfs file"
1344                                 " fadump_release_mem (%d)\n", rc);
1345         }
1346         return;
1347 }
1348
1349 /*
1350  * Prepare for firmware-assisted dump.
1351  */
1352 int __init setup_fadump(void)
1353 {
1354         if (!fw_dump.fadump_enabled)
1355                 return 0;
1356
1357         if (!fw_dump.fadump_supported) {
1358                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1359                         " this hardware\n");
1360                 return 0;
1361         }
1362
1363         fadump_show_config();
1364         /*
1365          * If dump data is available then see if it is valid and prepare for
1366          * saving it to the disk.
1367          */
1368         if (fw_dump.dump_active) {
1369                 /*
1370                  * if dump process fails then invalidate the registration
1371                  * and release memory before proceeding for re-registration.
1372                  */
1373                 if (process_fadump(fdm_active) < 0)
1374                         fadump_invalidate_release_mem();
1375         }
1376         /* Initialize the kernel dump memory structure for FAD registration. */
1377         else if (fw_dump.reserve_dump_area_size)
1378                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1379         fadump_init_files();
1380
1381         return 1;
1382 }
1383 subsys_initcall(setup_fadump);