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