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 __be32 *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 = be32_to_cpu(*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 = cpu_to_be32(0x00000001);
 154         fdm->header.dump_num_sections = cpu_to_be16(3);
 155         fdm->header.dump_status_flag = 0;
 156         fdm->header.offset_first_dump_section =
 157                 cpu_to_be32((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 = cpu_to_be32(FADUMP_REQUEST_FLAG);
 174         fdm->cpu_state_data.source_data_type = cpu_to_be16(FADUMP_CPU_STATE_DATA);
 175         fdm->cpu_state_data.source_address = 0;
 176         fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
 177         fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
 178         addr += fw_dump.cpu_state_data_size;
 179
 180         /* hpte region section */
 181         fdm->hpte_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 182         fdm->hpte_region.source_data_type = cpu_to_be16(FADUMP_HPTE_REGION);
 183         fdm->hpte_region.source_address = 0;
 184         fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
 185         fdm->hpte_region.destination_address = cpu_to_be64(addr);
 186         addr += fw_dump.hpte_region_size;
 187
 188         /* RMA region section */
 189         fdm->rmr_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
 190         fdm->rmr_region.source_data_type = cpu_to_be16(FADUMP_REAL_MODE_REGION);
 191         fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
 192         fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
 193         fdm->rmr_region.destination_address = cpu_to_be64(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 = be64_to_cpu(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                                 be64_to_cpu(fdm_active->rmr_region.destination_address) +
 321                                 be64_to_cpu(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 int register_fw_dump(struct fadump_mem_struct *fdm)
 364 {
 365         int rc, err;
 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         err = -EIO;
 383         switch (rc) {
 384         default:
 385                 pr_err("Failed to register. Unknown Error(%d).\n", rc);
 386                 break;
 387         case -1:
 388                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 389                         " dump. Hardware Error(%d).\n", rc);
 390                 break;
 391         case -3:
 392                 printk(KERN_ERR "Failed to register firmware-assisted kernel"
 393                         " dump. Parameter Error(%d).\n", rc);
 394                 err = -EINVAL;
 395                 break;
 396         case -9:
 397                 printk(KERN_ERR "firmware-assisted kernel dump is already "
 398                         " registered.");
 399                 fw_dump.dump_registered = 1;
 400                 err = -EEXIST;
 401                 break;
 402         case 0:
 403                 printk(KERN_INFO "firmware-assisted kernel dump registration"
 404                         " is successful\n");
 405                 fw_dump.dump_registered = 1;
 406                 err = 0;
 407                 break;
 408         }
 409         return err;
 410 }
 411
 412 void crash_fadump(struct pt_regs *regs, const char *str)
 413 {
 414         struct fadump_crash_info_header *fdh = NULL;
 415
 416         if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr)
 417                 return;
 418
 419         fdh = __va(fw_dump.fadumphdr_addr);
 420         crashing_cpu = smp_processor_id();
 421         fdh->crashing_cpu = crashing_cpu;
 422         crash_save_vmcoreinfo();
 423
 424         if (regs)
 425                 fdh->regs = *regs;
 426         else
 427                 ppc_save_regs(&fdh->regs);
 428
 429         fdh->cpu_online_mask = *cpu_online_mask;
 430
 431         /* Call ibm,os-term rtas call to trigger firmware assisted dump */
 432         rtas_os_term((char *)str);
 433 }
 434
 435 #define GPR_MASK        0xffffff0000000000
 436 static inline int fadump_gpr_index(u64 id)
 437 {
 438         int i = -1;
 439         char str[3];
 440
 441         if ((id & GPR_MASK) == REG_ID("GPR")) {
 442                 /* get the digits at the end */
 443                 id &= ~GPR_MASK;
 444                 id >>= 24;
 445                 str[2] = '\0';
 446                 str[1] = id & 0xff;
 447                 str[0] = (id >> 8) & 0xff;
 448                 sscanf(str, "%d", &i);
 449                 if (i > 31)
 450                         i = -1;
 451         }
 452         return i;
 453 }
 454
 455 static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id,
 456                                                                 u64 reg_val)
 457 {
 458         int i;
 459
 460         i = fadump_gpr_index(reg_id);
 461         if (i >= 0)
 462                 regs->gpr[i] = (unsigned long)reg_val;
 463         else if (reg_id == REG_ID("NIA"))
 464                 regs->nip = (unsigned long)reg_val;
 465         else if (reg_id == REG_ID("MSR"))
 466                 regs->msr = (unsigned long)reg_val;
 467         else if (reg_id == REG_ID("CTR"))
 468                 regs->ctr = (unsigned long)reg_val;
 469         else if (reg_id == REG_ID("LR"))
 470                 regs->link = (unsigned long)reg_val;
 471         else if (reg_id == REG_ID("XER"))
 472                 regs->xer = (unsigned long)reg_val;
 473         else if (reg_id == REG_ID("CR"))
 474                 regs->ccr = (unsigned long)reg_val;
 475         else if (reg_id == REG_ID("DAR"))
 476                 regs->dar = (unsigned long)reg_val;
 477         else if (reg_id == REG_ID("DSISR"))
 478                 regs->dsisr = (unsigned long)reg_val;
 479 }
 480
 481 static struct fadump_reg_entry*
 482 fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs)
 483 {
 484         memset(regs, 0, sizeof(struct pt_regs));
 485
 486         while (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUEND")) {
 487                 fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
 488                                         be64_to_cpu(reg_entry->reg_value));
 489                 reg_entry++;
 490         }
 491         reg_entry++;
 492         return reg_entry;
 493 }
 494
 495 static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type,
 496                                                 void *data, size_t data_len)
 497 {
 498         struct elf_note note;
 499
 500         note.n_namesz = strlen(name) + 1;
 501         note.n_descsz = data_len;
 502         note.n_type   = type;
 503         memcpy(buf, &note, sizeof(note));
 504         buf += (sizeof(note) + 3)/4;
 505         memcpy(buf, name, note.n_namesz);
 506         buf += (note.n_namesz + 3)/4;
 507         memcpy(buf, data, note.n_descsz);
 508         buf += (note.n_descsz + 3)/4;
 509
 510         return buf;
 511 }
 512
 513 static void fadump_final_note(u32 *buf)
 514 {
 515         struct elf_note note;
 516
 517         note.n_namesz = 0;
 518         note.n_descsz = 0;
 519         note.n_type   = 0;
 520         memcpy(buf, &note, sizeof(note));
 521 }
 522
 523 static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs)
 524 {
 525         struct elf_prstatus prstatus;
 526
 527         memset(&prstatus, 0, sizeof(prstatus));
 528         /*
 529          * FIXME: How do i get PID? Do I really need it?
 530          * prstatus.pr_pid = ????
 531          */
 532         elf_core_copy_kernel_regs(&prstatus.pr_reg, regs);
 533         buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS,
 534                                 &prstatus, sizeof(prstatus));
 535         return buf;
 536 }
 537
 538 static void fadump_update_elfcore_header(char *bufp)
 539 {
 540         struct elfhdr *elf;
 541         struct elf_phdr *phdr;
 542
 543         elf = (struct elfhdr *)bufp;
 544         bufp += sizeof(struct elfhdr);
 545
 546         /* First note is a place holder for cpu notes info. */
 547         phdr = (struct elf_phdr *)bufp;
 548
 549         if (phdr->p_type == PT_NOTE) {
 550                 phdr->p_paddr = fw_dump.cpu_notes_buf;
 551                 phdr->p_offset  = phdr->p_paddr;
 552                 phdr->p_filesz  = fw_dump.cpu_notes_buf_size;
 553                 phdr->p_memsz = fw_dump.cpu_notes_buf_size;
 554         }
 555         return;
 556 }
 557
 558 static void *fadump_cpu_notes_buf_alloc(unsigned long size)
 559 {
 560         void *vaddr;
 561         struct page *page;
 562         unsigned long order, count, i;
 563
 564         order = get_order(size);
 565         vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
 566         if (!vaddr)
 567                 return NULL;
 568
 569         count = 1 << order;
 570         page = virt_to_page(vaddr);
 571         for (i = 0; i < count; i++)
 572                 SetPageReserved(page + i);
 573         return vaddr;
 574 }
 575
 576 static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size)
 577 {
 578         struct page *page;
 579         unsigned long order, count, i;
 580
 581         order = get_order(size);
 582         count = 1 << order;
 583         page = virt_to_page(vaddr);
 584         for (i = 0; i < count; i++)
 585                 ClearPageReserved(page + i);
 586         __free_pages(page, order);
 587 }
 588
 589 /*
 590  * Read CPU state dump data and convert it into ELF notes.
 591  * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
 592  * used to access the data to allow for additional fields to be added without
 593  * affecting compatibility. Each list of registers for a CPU starts with
 594  * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
 595  * 8 Byte ASCII identifier and 8 Byte register value. The register entry
 596  * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
 597  * of register value. For more details refer to PAPR document.
 598  *
 599  * Only for the crashing cpu we ignore the CPU dump data and get exact
 600  * state from fadump crash info structure populated by first kernel at the
 601  * time of crash.
 602  */
 603 static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
 604 {
 605         struct fadump_reg_save_area_header *reg_header;
 606         struct fadump_reg_entry *reg_entry;
 607         struct fadump_crash_info_header *fdh = NULL;
 608         void *vaddr;
 609         unsigned long addr;
 610         u32 num_cpus, *note_buf;
 611         struct pt_regs regs;
 612         int i, rc = 0, cpu = 0;
 613
 614         if (!fdm->cpu_state_data.bytes_dumped)
 615                 return -EINVAL;
 616
 617         addr = be64_to_cpu(fdm->cpu_state_data.destination_address);
 618         vaddr = __va(addr);
 619
 620         reg_header = vaddr;
 621         if (be64_to_cpu(reg_header->magic_number) != REGSAVE_AREA_MAGIC) {
 622                 printk(KERN_ERR "Unable to read register save area.\n");
 623                 return -ENOENT;
 624         }
 625         pr_debug("--------CPU State Data------------\n");
 626         pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
 627         pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
 628
 629         vaddr += be32_to_cpu(reg_header->num_cpu_offset);
 630         num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
 631         pr_debug("NumCpus     : %u\n", num_cpus);
 632         vaddr += sizeof(u32);
 633         reg_entry = (struct fadump_reg_entry *)vaddr;
 634
 635         /* Allocate buffer to hold cpu crash notes. */
 636         fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t);
 637         fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size);
 638         note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size);
 639         if (!note_buf) {
 640                 printk(KERN_ERR "Failed to allocate 0x%lx bytes for "
 641                         "cpu notes buffer\n", fw_dump.cpu_notes_buf_size);
 642                 return -ENOMEM;
 643         }
 644         fw_dump.cpu_notes_buf = __pa(note_buf);
 645
 646         pr_debug("Allocated buffer for cpu notes of size %ld at %p\n",
 647                         (num_cpus * sizeof(note_buf_t)), note_buf);
 648
 649         if (fw_dump.fadumphdr_addr)
 650                 fdh = __va(fw_dump.fadumphdr_addr);
 651
 652         for (i = 0; i < num_cpus; i++) {
 653                 if (be64_to_cpu(reg_entry->reg_id) != REG_ID("CPUSTRT")) {
 654                         printk(KERN_ERR "Unable to read CPU state data\n");
 655                         rc = -ENOENT;
 656                         goto error_out;
 657                 }
 658                 /* Lower 4 bytes of reg_value contains logical cpu id */
 659                 cpu = be64_to_cpu(reg_entry->reg_value) & FADUMP_CPU_ID_MASK;
 660                 if (fdh && !cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) {
 661                         SKIP_TO_NEXT_CPU(reg_entry);
 662                         continue;
 663                 }
 664                 pr_debug("Reading register data for cpu %d...\n", cpu);
 665                 if (fdh && fdh->crashing_cpu == cpu) {
 666                         regs = fdh->regs;
 667                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 668                         SKIP_TO_NEXT_CPU(reg_entry);
 669                 } else {
 670                         reg_entry++;
 671                         reg_entry = fadump_read_registers(reg_entry, &regs);
 672                         note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
 673                 }
 674         }
 675         fadump_final_note(note_buf);
 676
 677         if (fdh) {
 678                 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
 679                                                         fdh->elfcorehdr_addr);
 680                 fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr));
 681         }
 682         return 0;
 683
 684 error_out:
 685         fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf),
 686                                         fw_dump.cpu_notes_buf_size);
 687         fw_dump.cpu_notes_buf = 0;
 688         fw_dump.cpu_notes_buf_size = 0;
 689         return rc;
 690
 691 }
 692
 693 /*
 694  * Validate and process the dump data stored by firmware before exporting
 695  * it through '/proc/vmcore'.
 696  */
 697 static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
 698 {
 699         struct fadump_crash_info_header *fdh;
 700         int rc = 0;
 701
 702         if (!fdm_active || !fw_dump.fadumphdr_addr)
 703                 return -EINVAL;
 704
 705         /* Check if the dump data is valid. */
 706         if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
 707                         (fdm_active->cpu_state_data.error_flags != 0) ||
 708                         (fdm_active->rmr_region.error_flags != 0)) {
 709                 printk(KERN_ERR "Dump taken by platform is not valid\n");
 710                 return -EINVAL;
 711         }
 712         if ((fdm_active->rmr_region.bytes_dumped !=
 713                         fdm_active->rmr_region.source_len) ||
 714                         !fdm_active->cpu_state_data.bytes_dumped) {
 715                 printk(KERN_ERR "Dump taken by platform is incomplete\n");
 716                 return -EINVAL;
 717         }
 718
 719         /* Validate the fadump crash info header */
 720         fdh = __va(fw_dump.fadumphdr_addr);
 721         if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
 722                 printk(KERN_ERR "Crash info header is not valid.\n");
 723                 return -EINVAL;
 724         }
 725
 726         rc = fadump_build_cpu_notes(fdm_active);
 727         if (rc)
 728                 return rc;
 729
 730         /*
 731          * We are done validating dump info and elfcore header is now ready
 732          * to be exported. set elfcorehdr_addr so that vmcore module will
 733          * export the elfcore header through '/proc/vmcore'.
 734          */
 735         elfcorehdr_addr = fdh->elfcorehdr_addr;
 736
 737         return 0;
 738 }
 739
 740 static void free_crash_memory_ranges(void)
 741 {
 742         kfree(crash_memory_ranges);
 743         crash_memory_ranges = NULL;
 744         crash_memory_ranges_size = 0;
 745         max_crash_mem_ranges = 0;
 746 }
 747
 748 /*
 749  * Allocate or reallocate crash memory ranges array in incremental units
 750  * of PAGE_SIZE.
 751  */
 752 static int allocate_crash_memory_ranges(void)
 753 {
 754         struct fad_crash_memory_ranges *new_array;
 755         u64 new_size;
 756
 757         new_size = crash_memory_ranges_size + PAGE_SIZE;
 758         pr_debug("Allocating %llu bytes of memory for crash memory ranges\n",
 759                  new_size);
 760
 761         new_array = krealloc(crash_memory_ranges, new_size, GFP_KERNEL);
 762         if (new_array == NULL) {
 763                 pr_err("Insufficient memory for setting up crash memory ranges\n");
 764                 free_crash_memory_ranges();
 765                 return -ENOMEM;
 766         }
 767
 768         crash_memory_ranges = new_array;
 769         crash_memory_ranges_size = new_size;
 770         max_crash_mem_ranges = (new_size /
 771                                 sizeof(struct fad_crash_memory_ranges));
 772         return 0;
 773 }
 774
 775 static inline int fadump_add_crash_memory(unsigned long long base,
 776                                           unsigned long long end)
 777 {
 778         if (base == end)
 779                 return 0;
 780
 781         if (crash_mem_ranges == max_crash_mem_ranges) {
 782                 int ret;
 783
 784                 ret = allocate_crash_memory_ranges();
 785                 if (ret)
 786                         return ret;
 787         }
 788
 789         pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n",
 790                 crash_mem_ranges, base, end - 1, (end - base));
 791         crash_memory_ranges[crash_mem_ranges].base = base;
 792         crash_memory_ranges[crash_mem_ranges].size = end - base;
 793         crash_mem_ranges++;
 794         return 0;
 795 }
 796
 797 static int fadump_exclude_reserved_area(unsigned long long start,
 798                                         unsigned long long end)
 799 {
 800         unsigned long long ra_start, ra_end;
 801         int ret = 0;
 802
 803         ra_start = fw_dump.reserve_dump_area_start;
 804         ra_end = ra_start + fw_dump.reserve_dump_area_size;
 805
 806         if ((ra_start < end) && (ra_end > start)) {
 807                 if ((start < ra_start) && (end > ra_end)) {
 808                         ret = fadump_add_crash_memory(start, ra_start);
 809                         if (ret)
 810                                 return ret;
 811
 812                         ret = fadump_add_crash_memory(ra_end, end);
 813                 } else if (start < ra_start) {
 814                         ret = fadump_add_crash_memory(start, ra_start);
 815                 } else if (ra_end < end) {
 816                         ret = fadump_add_crash_memory(ra_end, end);
 817                 }
 818         } else
 819                 ret = fadump_add_crash_memory(start, end);
 820
 821         return ret;
 822 }
 823
 824 static int fadump_init_elfcore_header(char *bufp)
 825 {
 826         struct elfhdr *elf;
 827
 828         elf = (struct elfhdr *) bufp;
 829         bufp += sizeof(struct elfhdr);
 830         memcpy(elf->e_ident, ELFMAG, SELFMAG);
 831         elf->e_ident[EI_CLASS] = ELF_CLASS;
 832         elf->e_ident[EI_DATA] = ELF_DATA;
 833         elf->e_ident[EI_VERSION] = EV_CURRENT;
 834         elf->e_ident[EI_OSABI] = ELF_OSABI;
 835         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
 836         elf->e_type = ET_CORE;
 837         elf->e_machine = ELF_ARCH;
 838         elf->e_version = EV_CURRENT;
 839         elf->e_entry = 0;
 840         elf->e_phoff = sizeof(struct elfhdr);
 841         elf->e_shoff = 0;
 842         elf->e_flags = ELF_CORE_EFLAGS;
 843         elf->e_ehsize = sizeof(struct elfhdr);
 844         elf->e_phentsize = sizeof(struct elf_phdr);
 845         elf->e_phnum = 0;
 846         elf->e_shentsize = 0;
 847         elf->e_shnum = 0;
 848         elf->e_shstrndx = 0;
 849
 850         return 0;
 851 }
 852
 853 /*
 854  * Traverse through memblock structure and setup crash memory ranges. These
 855  * ranges will be used create PT_LOAD program headers in elfcore header.
 856  */
 857 static int fadump_setup_crash_memory_ranges(void)
 858 {
 859         struct memblock_region *reg;
 860         unsigned long long start, end;
 861         int ret;
 862
 863         pr_debug("Setup crash memory ranges.\n");
 864         crash_mem_ranges = 0;
 865         /*
 866          * add the first memory chunk (RMA_START through boot_memory_size) as
 867          * a separate memory chunk. The reason is, at the time crash firmware
 868          * will move the content of this memory chunk to different location
 869          * specified during fadump registration. We need to create a separate
 870          * program header for this chunk with the correct offset.
 871          */
 872         ret = fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size);
 873         if (ret)
 874                 return ret;
 875
 876         for_each_memblock(memory, reg) {
 877                 start = (unsigned long long)reg->base;
 878                 end = start + (unsigned long long)reg->size;
 879                 if (start == RMA_START && end >= fw_dump.boot_memory_size)
 880                         start = fw_dump.boot_memory_size;
 881
 882                 /* add this range excluding the reserved dump area. */
 883                 ret = fadump_exclude_reserved_area(start, end);
 884                 if (ret)
 885                         return ret;
 886         }
 887
 888         return 0;
 889 }
 890
 891 /*
 892  * If the given physical address falls within the boot memory region then
 893  * return the relocated address that points to the dump region reserved
 894  * for saving initial boot memory contents.
 895  */
 896 static inline unsigned long fadump_relocate(unsigned long paddr)
 897 {
 898         if (paddr > RMA_START && paddr < fw_dump.boot_memory_size)
 899                 return be64_to_cpu(fdm.rmr_region.destination_address) + paddr;
 900         else
 901                 return paddr;
 902 }
 903
 904 static int fadump_create_elfcore_headers(char *bufp)
 905 {
 906         struct elfhdr *elf;
 907         struct elf_phdr *phdr;
 908         int i;
 909
 910         fadump_init_elfcore_header(bufp);
 911         elf = (struct elfhdr *)bufp;
 912         bufp += sizeof(struct elfhdr);
 913
 914         /*
 915          * setup ELF PT_NOTE, place holder for cpu notes info. The notes info
 916          * will be populated during second kernel boot after crash. Hence
 917          * this PT_NOTE will always be the first elf note.
 918          *
 919          * NOTE: Any new ELF note addition should be placed after this note.
 920          */
 921         phdr = (struct elf_phdr *)bufp;
 922         bufp += sizeof(struct elf_phdr);
 923         phdr->p_type = PT_NOTE;
 924         phdr->p_flags = 0;
 925         phdr->p_vaddr = 0;
 926         phdr->p_align = 0;
 927
 928         phdr->p_offset = 0;
 929         phdr->p_paddr = 0;
 930         phdr->p_filesz = 0;
 931         phdr->p_memsz = 0;
 932
 933         (elf->e_phnum)++;
 934
 935         /* setup ELF PT_NOTE for vmcoreinfo */
 936         phdr = (struct elf_phdr *)bufp;
 937         bufp += sizeof(struct elf_phdr);
 938         phdr->p_type    = PT_NOTE;
 939         phdr->p_flags   = 0;
 940         phdr->p_vaddr   = 0;
 941         phdr->p_align   = 0;
 942
 943         phdr->p_paddr   = fadump_relocate(paddr_vmcoreinfo_note());
 944         phdr->p_offset  = phdr->p_paddr;
 945         phdr->p_memsz   = vmcoreinfo_max_size;
 946         phdr->p_filesz  = vmcoreinfo_max_size;
 947
 948         /* Increment number of program headers. */
 949         (elf->e_phnum)++;
 950
 951         /* setup PT_LOAD sections. */
 952
 953         for (i = 0; i < crash_mem_ranges; i++) {
 954                 unsigned long long mbase, msize;
 955                 mbase = crash_memory_ranges[i].base;
 956                 msize = crash_memory_ranges[i].size;
 957
 958                 if (!msize)
 959                         continue;
 960
 961                 phdr = (struct elf_phdr *)bufp;
 962                 bufp += sizeof(struct elf_phdr);
 963                 phdr->p_type    = PT_LOAD;
 964                 phdr->p_flags   = PF_R|PF_W|PF_X;
 965                 phdr->p_offset  = mbase;
 966
 967                 if (mbase == RMA_START) {
 968                         /*
 969                          * The entire RMA region will be moved by firmware
 970                          * to the specified destination_address. Hence set
 971                          * the correct offset.
 972                          */
 973                         phdr->p_offset = be64_to_cpu(fdm.rmr_region.destination_address);
 974                 }
 975
 976                 phdr->p_paddr = mbase;
 977                 phdr->p_vaddr = (unsigned long)__va(mbase);
 978                 phdr->p_filesz = msize;
 979                 phdr->p_memsz = msize;
 980                 phdr->p_align = 0;
 981
 982                 /* Increment number of program headers. */
 983                 (elf->e_phnum)++;
 984         }
 985         return 0;
 986 }
 987
 988 static unsigned long init_fadump_header(unsigned long addr)
 989 {
 990         struct fadump_crash_info_header *fdh;
 991
 992         if (!addr)
 993                 return 0;
 994
 995         fw_dump.fadumphdr_addr = addr;
 996         fdh = __va(addr);
 997         addr += sizeof(struct fadump_crash_info_header);
 998
 999         memset(fdh, 0, sizeof(struct fadump_crash_info_header));
1000         fdh->magic_number = FADUMP_CRASH_INFO_MAGIC;
1001         fdh->elfcorehdr_addr = addr;
1002         /* We will set the crashing cpu id in crash_fadump() during crash. */
1003         fdh->crashing_cpu = CPU_UNKNOWN;
1004
1005         return addr;
1006 }
1007
1008 static int register_fadump(void)
1009 {
1010         unsigned long addr;
1011         void *vaddr;
1012         int ret;
1013
1014         /*
1015          * If no memory is reserved then we can not register for firmware-
1016          * assisted dump.
1017          */
1018         if (!fw_dump.reserve_dump_area_size)
1019                 return -ENODEV;
1020
1021         ret = fadump_setup_crash_memory_ranges();
1022         if (ret)
1023                 return ret;
1024
1025         addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
1026         /* Initialize fadump crash info header. */
1027         addr = init_fadump_header(addr);
1028         vaddr = __va(addr);
1029
1030         pr_debug("Creating ELF core headers at %#016lx\n", addr);
1031         fadump_create_elfcore_headers(vaddr);
1032
1033         /* register the future kernel dump with firmware. */
1034         return register_fw_dump(&fdm);
1035 }
1036
1037 static int fadump_unregister_dump(struct fadump_mem_struct *fdm)
1038 {
1039         int rc = 0;
1040         unsigned int wait_time;
1041
1042         pr_debug("Un-register firmware-assisted dump\n");
1043
1044         /* TODO: Add upper time limit for the delay */
1045         do {
1046                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1047                         FADUMP_UNREGISTER, fdm,
1048                         sizeof(struct fadump_mem_struct));
1049
1050                 wait_time = rtas_busy_delay_time(rc);
1051                 if (wait_time)
1052                         mdelay(wait_time);
1053         } while (wait_time);
1054
1055         if (rc) {
1056                 printk(KERN_ERR "Failed to un-register firmware-assisted dump."
1057                         " unexpected error(%d).\n", rc);
1058                 return rc;
1059         }
1060         fw_dump.dump_registered = 0;
1061         return 0;
1062 }
1063
1064 static int fadump_invalidate_dump(struct fadump_mem_struct *fdm)
1065 {
1066         int rc = 0;
1067         unsigned int wait_time;
1068
1069         pr_debug("Invalidating firmware-assisted dump registration\n");
1070
1071         /* TODO: Add upper time limit for the delay */
1072         do {
1073                 rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL,
1074                         FADUMP_INVALIDATE, fdm,
1075                         sizeof(struct fadump_mem_struct));
1076
1077                 wait_time = rtas_busy_delay_time(rc);
1078                 if (wait_time)
1079                         mdelay(wait_time);
1080         } while (wait_time);
1081
1082         if (rc) {
1083                 printk(KERN_ERR "Failed to invalidate firmware-assisted dump "
1084                         "rgistration. unexpected error(%d).\n", rc);
1085                 return rc;
1086         }
1087         fw_dump.dump_active = 0;
1088         fdm_active = NULL;
1089         return 0;
1090 }
1091
1092 void fadump_cleanup(void)
1093 {
1094         /* Invalidate the registration only if dump is active. */
1095         if (fw_dump.dump_active) {
1096                 init_fadump_mem_struct(&fdm,
1097                         be64_to_cpu(fdm_active->cpu_state_data.destination_address));
1098                 fadump_invalidate_dump(&fdm);
1099         } else if (fw_dump.dump_registered) {
1100                 /* Un-register Firmware-assisted dump if it was registered. */
1101                 fadump_unregister_dump(&fdm);
1102                 free_crash_memory_ranges();
1103         }
1104 }
1105
1106 /*
1107  * Release the memory that was reserved in early boot to preserve the memory
1108  * contents. The released memory will be available for general use.
1109  */
1110 static void fadump_release_memory(unsigned long begin, unsigned long end)
1111 {
1112         unsigned long addr;
1113         unsigned long ra_start, ra_end;
1114
1115         ra_start = fw_dump.reserve_dump_area_start;
1116         ra_end = ra_start + fw_dump.reserve_dump_area_size;
1117
1118         for (addr = begin; addr < end; addr += PAGE_SIZE) {
1119                 /*
1120                  * exclude the dump reserve area. Will reuse it for next
1121                  * fadump registration.
1122                  */
1123                 if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start))
1124                         continue;
1125
1126                 free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
1127         }
1128 }
1129
1130 static void fadump_invalidate_release_mem(void)
1131 {
1132         unsigned long reserved_area_start, reserved_area_end;
1133         unsigned long destination_address;
1134
1135         mutex_lock(&fadump_mutex);
1136         if (!fw_dump.dump_active) {
1137                 mutex_unlock(&fadump_mutex);
1138                 return;
1139         }
1140
1141         destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
1142         fadump_cleanup();
1143         mutex_unlock(&fadump_mutex);
1144
1145         /*
1146          * Save the current reserved memory bounds we will require them
1147          * later for releasing the memory for general use.
1148          */
1149         reserved_area_start = fw_dump.reserve_dump_area_start;
1150         reserved_area_end = reserved_area_start +
1151                         fw_dump.reserve_dump_area_size;
1152         /*
1153          * Setup reserve_dump_area_start and its size so that we can
1154          * reuse this reserved memory for Re-registration.
1155          */
1156         fw_dump.reserve_dump_area_start = destination_address;
1157         fw_dump.reserve_dump_area_size = get_fadump_area_size();
1158
1159         fadump_release_memory(reserved_area_start, reserved_area_end);
1160         if (fw_dump.cpu_notes_buf) {
1161                 fadump_cpu_notes_buf_free(
1162                                 (unsigned long)__va(fw_dump.cpu_notes_buf),
1163                                 fw_dump.cpu_notes_buf_size);
1164                 fw_dump.cpu_notes_buf = 0;
1165                 fw_dump.cpu_notes_buf_size = 0;
1166         }
1167         /* Initialize the kernel dump memory structure for FAD registration. */
1168         init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1169 }
1170
1171 static ssize_t fadump_release_memory_store(struct kobject *kobj,
1172                                         struct kobj_attribute *attr,
1173                                         const char *buf, size_t count)
1174 {
1175         if (!fw_dump.dump_active)
1176                 return -EPERM;
1177
1178         if (buf[0] == '1') {
1179                 /*
1180                  * Take away the '/proc/vmcore'. We are releasing the dump
1181                  * memory, hence it will not be valid anymore.
1182                  */
1183                 vmcore_cleanup();
1184                 fadump_invalidate_release_mem();
1185
1186         } else
1187                 return -EINVAL;
1188         return count;
1189 }
1190
1191 static ssize_t fadump_enabled_show(struct kobject *kobj,
1192                                         struct kobj_attribute *attr,
1193                                         char *buf)
1194 {
1195         return sprintf(buf, "%d\n", fw_dump.fadump_enabled);
1196 }
1197
1198 static ssize_t fadump_register_show(struct kobject *kobj,
1199                                         struct kobj_attribute *attr,
1200                                         char *buf)
1201 {
1202         return sprintf(buf, "%d\n", fw_dump.dump_registered);
1203 }
1204
1205 static ssize_t fadump_register_store(struct kobject *kobj,
1206                                         struct kobj_attribute *attr,
1207                                         const char *buf, size_t count)
1208 {
1209         int ret = 0;
1210
1211         if (!fw_dump.fadump_enabled || fdm_active)
1212                 return -EPERM;
1213
1214         mutex_lock(&fadump_mutex);
1215
1216         switch (buf[0]) {
1217         case '0':
1218                 if (fw_dump.dump_registered == 0) {
1219                         goto unlock_out;
1220                 }
1221                 /* Un-register Firmware-assisted dump */
1222                 fadump_unregister_dump(&fdm);
1223                 break;
1224         case '1':
1225                 if (fw_dump.dump_registered == 1) {
1226                         ret = -EEXIST;
1227                         goto unlock_out;
1228                 }
1229                 /* Register Firmware-assisted dump */
1230                 ret = register_fadump();
1231                 break;
1232         default:
1233                 ret = -EINVAL;
1234                 break;
1235         }
1236
1237 unlock_out:
1238         mutex_unlock(&fadump_mutex);
1239         return ret < 0 ? ret : count;
1240 }
1241
1242 static int fadump_region_show(struct seq_file *m, void *private)
1243 {
1244         const struct fadump_mem_struct *fdm_ptr;
1245
1246         if (!fw_dump.fadump_enabled)
1247                 return 0;
1248
1249         mutex_lock(&fadump_mutex);
1250         if (fdm_active)
1251                 fdm_ptr = fdm_active;
1252         else {
1253                 mutex_unlock(&fadump_mutex);
1254                 fdm_ptr = &fdm;
1255         }
1256
1257         seq_printf(m,
1258                         "CPU : [%#016llx-%#016llx] %#llx bytes, "
1259                         "Dumped: %#llx\n",
1260                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address),
1261                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) +
1262                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len) - 1,
1263                         be64_to_cpu(fdm_ptr->cpu_state_data.source_len),
1264                         be64_to_cpu(fdm_ptr->cpu_state_data.bytes_dumped));
1265         seq_printf(m,
1266                         "HPTE: [%#016llx-%#016llx] %#llx bytes, "
1267                         "Dumped: %#llx\n",
1268                         be64_to_cpu(fdm_ptr->hpte_region.destination_address),
1269                         be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
1270                         be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
1271                         be64_to_cpu(fdm_ptr->hpte_region.source_len),
1272                         be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
1273         seq_printf(m,
1274                         "DUMP: [%#016llx-%#016llx] %#llx bytes, "
1275                         "Dumped: %#llx\n",
1276                         be64_to_cpu(fdm_ptr->rmr_region.destination_address),
1277                         be64_to_cpu(fdm_ptr->rmr_region.destination_address) +
1278                         be64_to_cpu(fdm_ptr->rmr_region.source_len) - 1,
1279                         be64_to_cpu(fdm_ptr->rmr_region.source_len),
1280                         be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
1281
1282         if (!fdm_active ||
1283                 (fw_dump.reserve_dump_area_start ==
1284                 be64_to_cpu(fdm_ptr->cpu_state_data.destination_address)))
1285                 goto out;
1286
1287         /* Dump is active. Show reserved memory region. */
1288         seq_printf(m,
1289                         "    : [%#016llx-%#016llx] %#llx bytes, "
1290                         "Dumped: %#llx\n",
1291                         (unsigned long long)fw_dump.reserve_dump_area_start,
1292                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) - 1,
1293                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1294                         fw_dump.reserve_dump_area_start,
1295                         be64_to_cpu(fdm_ptr->cpu_state_data.destination_address) -
1296                         fw_dump.reserve_dump_area_start);
1297 out:
1298         if (fdm_active)
1299                 mutex_unlock(&fadump_mutex);
1300         return 0;
1301 }
1302
1303 static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem,
1304                                                 0200, NULL,
1305                                                 fadump_release_memory_store);
1306 static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled,
1307                                                 0444, fadump_enabled_show,
1308                                                 NULL);
1309 static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered,
1310                                                 0644, fadump_register_show,
1311                                                 fadump_register_store);
1312
1313 static int fadump_region_open(struct inode *inode, struct file *file)
1314 {
1315         return single_open(file, fadump_region_show, inode->i_private);
1316 }
1317
1318 static const struct file_operations fadump_region_fops = {
1319         .open    = fadump_region_open,
1320         .read    = seq_read,
1321         .llseek  = seq_lseek,
1322         .release = single_release,
1323 };
1324
1325 static void fadump_init_files(void)
1326 {
1327         struct dentry *debugfs_file;
1328         int rc = 0;
1329
1330         rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr);
1331         if (rc)
1332                 printk(KERN_ERR "fadump: unable to create sysfs file"
1333                         " fadump_enabled (%d)\n", rc);
1334
1335         rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr);
1336         if (rc)
1337                 printk(KERN_ERR "fadump: unable to create sysfs file"
1338                         " fadump_registered (%d)\n", rc);
1339
1340         debugfs_file = debugfs_create_file("fadump_region", 0444,
1341                                         powerpc_debugfs_root, NULL,
1342                                         &fadump_region_fops);
1343         if (!debugfs_file)
1344                 printk(KERN_ERR "fadump: unable to create debugfs file"
1345                                 " fadump_region\n");
1346
1347         if (fw_dump.dump_active) {
1348                 rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr);
1349                 if (rc)
1350                         printk(KERN_ERR "fadump: unable to create sysfs file"
1351                                 " fadump_release_mem (%d)\n", rc);
1352         }
1353         return;
1354 }
1355
1356 /*
1357  * Prepare for firmware-assisted dump.
1358  */
1359 int __init setup_fadump(void)
1360 {
1361         if (!fw_dump.fadump_enabled)
1362                 return 0;
1363
1364         if (!fw_dump.fadump_supported) {
1365                 printk(KERN_ERR "Firmware-assisted dump is not supported on"
1366                         " this hardware\n");
1367                 return 0;
1368         }
1369
1370         fadump_show_config();
1371         /*
1372          * If dump data is available then see if it is valid and prepare for
1373          * saving it to the disk.
1374          */
1375         if (fw_dump.dump_active) {
1376                 /*
1377                  * if dump process fails then invalidate the registration
1378                  * and release memory before proceeding for re-registration.
1379                  */
1380                 if (process_fadump(fdm_active) < 0)
1381                         fadump_invalidate_release_mem();
1382         }
1383         /* Initialize the kernel dump memory structure for FAD registration. */
1384         else if (fw_dump.reserve_dump_area_size)
1385                 init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
1386         fadump_init_files();
1387
1388         return 1;
1389 }
1390 subsys_initcall(setup_fadump);