/*
   * crash.c - kernel crash support code.
   * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
   *
   * This source code is licensed under the GNU General Public License,
   * Version 2.  See the file COPYING for more details.
   */
  
  #include <linux/crash_core.h>
  #include <linux/utsname.h>
  #include <linux/vmalloc.h>
  
  #include <asm/page.h>
  #include <asm/sections.h>
  
  /* vmcoreinfo stuff */

  static unsigned char *vmcoreinfo_data;

  static size_t vmcoreinfo_size;

  u32 *vmcoreinfo_note;

  /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
  static unsigned char *vmcoreinfo_data_safecopy;

  /*
   * parsing the "crashkernel" commandline
   *
   * this code is intended to be called from architecture specific code
   */
  
  
  /*
   * This function parses command lines in the format
   *
   *   crashkernel=ramsize-range:size[,...][@offset]
   *
   * The function returns 0 on success and -EINVAL on failure.
   */
  static int __init parse_crashkernel_mem(char *cmdline,
  					unsigned long long system_ram,
  					unsigned long long *crash_size,
  					unsigned long long *crash_base)
  {
  	char *cur = cmdline, *tmp;
  
  	/* for each entry of the comma-separated list */
  	do {
  		unsigned long long start, end = ULLONG_MAX, size;
  
  		/* get the start of the range */
  		start = memparse(cur, &tmp);
  		if (cur == tmp) {
  			pr_warn("crashkernel: Memory value expected
  ");
  			return -EINVAL;
  		}
  		cur = tmp;
  		if (*cur != '-') {
  			pr_warn("crashkernel: '-' expected
  ");
  			return -EINVAL;
  		}
  		cur++;
  
  		/* if no ':' is here, than we read the end */
  		if (*cur != ':') {
  			end = memparse(cur, &tmp);
  			if (cur == tmp) {
  				pr_warn("crashkernel: Memory value expected
  ");
  				return -EINVAL;
  			}
  			cur = tmp;
  			if (end <= start) {
  				pr_warn("crashkernel: end <= start
  ");
  				return -EINVAL;
  			}
  		}
  
  		if (*cur != ':') {
  			pr_warn("crashkernel: ':' expected
  ");
  			return -EINVAL;
  		}
  		cur++;
  
  		size = memparse(cur, &tmp);
  		if (cur == tmp) {
  			pr_warn("Memory value expected
  ");
  			return -EINVAL;
  		}
  		cur = tmp;
  		if (size >= system_ram) {
  			pr_warn("crashkernel: invalid size
  ");
  			return -EINVAL;
  		}
  
  		/* match ? */
  		if (system_ram >= start && system_ram < end) {
  			*crash_size = size;
  			break;
  		}
  	} while (*cur++ == ',');
  
  	if (*crash_size > 0) {
  		while (*cur && *cur != ' ' && *cur != '@')
  			cur++;
  		if (*cur == '@') {
  			cur++;
  			*crash_base = memparse(cur, &tmp);
  			if (cur == tmp) {
  				pr_warn("Memory value expected after '@'
  ");
  				return -EINVAL;
  			}
  		}
  	}
  
  	return 0;
  }
  
  /*
   * That function parses "simple" (old) crashkernel command lines like
   *
   *	crashkernel=size[@offset]
   *
   * It returns 0 on success and -EINVAL on failure.
   */
  static int __init parse_crashkernel_simple(char *cmdline,
  					   unsigned long long *crash_size,
  					   unsigned long long *crash_base)
  {
  	char *cur = cmdline;
  
  	*crash_size = memparse(cmdline, &cur);
  	if (cmdline == cur) {
  		pr_warn("crashkernel: memory value expected
  ");
  		return -EINVAL;
  	}
  
  	if (*cur == '@')
  		*crash_base = memparse(cur+1, &cur);
  	else if (*cur != ' ' && *cur != '\0') {
  		pr_warn("crashkernel: unrecognized char: %c
  ", *cur);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  #define SUFFIX_HIGH 0
  #define SUFFIX_LOW  1
  #define SUFFIX_NULL 2
  static __initdata char *suffix_tbl[] = {
  	[SUFFIX_HIGH] = ",high",
  	[SUFFIX_LOW]  = ",low",
  	[SUFFIX_NULL] = NULL,
  };
  
  /*
   * That function parses "suffix"  crashkernel command lines like
   *
   *	crashkernel=size,[high|low]
   *
   * It returns 0 on success and -EINVAL on failure.
   */
  static int __init parse_crashkernel_suffix(char *cmdline,
  					   unsigned long long	*crash_size,
  					   const char *suffix)
  {
  	char *cur = cmdline;
  
  	*crash_size = memparse(cmdline, &cur);
  	if (cmdline == cur) {
  		pr_warn("crashkernel: memory value expected
  ");
  		return -EINVAL;
  	}
  
  	/* check with suffix */
  	if (strncmp(cur, suffix, strlen(suffix))) {
  		pr_warn("crashkernel: unrecognized char: %c
  ", *cur);
  		return -EINVAL;
  	}
  	cur += strlen(suffix);
  	if (*cur != ' ' && *cur != '\0') {
  		pr_warn("crashkernel: unrecognized char: %c
  ", *cur);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static __init char *get_last_crashkernel(char *cmdline,
  			     const char *name,
  			     const char *suffix)
  {
  	char *p = cmdline, *ck_cmdline = NULL;
  
  	/* find crashkernel and use the last one if there are more */
  	p = strstr(p, name);
  	while (p) {
  		char *end_p = strchr(p, ' ');
  		char *q;
  
  		if (!end_p)
  			end_p = p + strlen(p);
  
  		if (!suffix) {
  			int i;
  
  			/* skip the one with any known suffix */
  			for (i = 0; suffix_tbl[i]; i++) {
  				q = end_p - strlen(suffix_tbl[i]);
  				if (!strncmp(q, suffix_tbl[i],
  					     strlen(suffix_tbl[i])))
  					goto next;
  			}
  			ck_cmdline = p;
  		} else {
  			q = end_p - strlen(suffix);
  			if (!strncmp(q, suffix, strlen(suffix)))
  				ck_cmdline = p;
  		}
  next:
  		p = strstr(p+1, name);
  	}
  
  	if (!ck_cmdline)
  		return NULL;
  
  	return ck_cmdline;
  }
  
  static int __init __parse_crashkernel(char *cmdline,
  			     unsigned long long system_ram,
  			     unsigned long long *crash_size,
  			     unsigned long long *crash_base,
  			     const char *name,
  			     const char *suffix)
  {
  	char	*first_colon, *first_space;
  	char	*ck_cmdline;
  
  	BUG_ON(!crash_size || !crash_base);
  	*crash_size = 0;
  	*crash_base = 0;
  
  	ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
  
  	if (!ck_cmdline)
  		return -EINVAL;
  
  	ck_cmdline += strlen(name);
  
  	if (suffix)
  		return parse_crashkernel_suffix(ck_cmdline, crash_size,
  				suffix);
  	/*
  	 * if the commandline contains a ':', then that's the extended
  	 * syntax -- if not, it must be the classic syntax
  	 */
  	first_colon = strchr(ck_cmdline, ':');
  	first_space = strchr(ck_cmdline, ' ');
  	if (first_colon && (!first_space || first_colon < first_space))
  		return parse_crashkernel_mem(ck_cmdline, system_ram,
  				crash_size, crash_base);
  
  	return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
  }
  
  /*
   * That function is the entry point for command line parsing and should be
   * called from the arch-specific code.
   */
  int __init parse_crashkernel(char *cmdline,
  			     unsigned long long system_ram,
  			     unsigned long long *crash_size,
  			     unsigned long long *crash_base)
  {
  	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
  					"crashkernel=", NULL);
  }
  
  int __init parse_crashkernel_high(char *cmdline,
  			     unsigned long long system_ram,
  			     unsigned long long *crash_size,
  			     unsigned long long *crash_base)
  {
  	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
  				"crashkernel=", suffix_tbl[SUFFIX_HIGH]);
  }
  
  int __init parse_crashkernel_low(char *cmdline,
  			     unsigned long long system_ram,
  			     unsigned long long *crash_size,
  			     unsigned long long *crash_base)
  {
  	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
  				"crashkernel=", suffix_tbl[SUFFIX_LOW]);
  }

  Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
  			  void *data, size_t data_len)

  {

  	struct elf_note *note = (struct elf_note *)buf;
  
  	note->n_namesz = strlen(name) + 1;
  	note->n_descsz = data_len;
  	note->n_type   = type;
  	buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
  	memcpy(buf, name, note->n_namesz);
  	buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
  	memcpy(buf, data, data_len);
  	buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));

  
  	return buf;
  }

  void final_note(Elf_Word *buf)

  {

  	memset(buf, 0, sizeof(struct elf_note));

  }
  
  static void update_vmcoreinfo_note(void)
  {
  	u32 *buf = vmcoreinfo_note;
  
  	if (!vmcoreinfo_size)
  		return;
  	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
  			      vmcoreinfo_size);
  	final_note(buf);
  }

  void crash_update_vmcoreinfo_safecopy(void *ptr)
  {
  	if (ptr)
  		memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
  
  	vmcoreinfo_data_safecopy = ptr;
  }

  void crash_save_vmcoreinfo(void)
  {

  	if (!vmcoreinfo_note)
  		return;

  	/* Use the safe copy to generate vmcoreinfo note if have */
  	if (vmcoreinfo_data_safecopy)
  		vmcoreinfo_data = vmcoreinfo_data_safecopy;

  	vmcoreinfo_append_str("CRASHTIME=%ld
  ", get_seconds());
  	update_vmcoreinfo_note();
  }
  
  void vmcoreinfo_append_str(const char *fmt, ...)
  {
  	va_list args;
  	char buf[0x50];
  	size_t r;
  
  	va_start(args, fmt);
  	r = vscnprintf(buf, sizeof(buf), fmt, args);
  	va_end(args);

  	r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);

  
  	memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
  
  	vmcoreinfo_size += r;
  }
  
  /*
   * provide an empty default implementation here -- architecture
   * code may override this
   */
  void __weak arch_crash_save_vmcoreinfo(void)
  {}
  
  phys_addr_t __weak paddr_vmcoreinfo_note(void)
  {

  	return __pa(vmcoreinfo_note);

  }
  
  static int __init crash_save_vmcoreinfo_init(void)
  {

  	vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
  	if (!vmcoreinfo_data) {
  		pr_warn("Memory allocation for vmcoreinfo_data failed
  ");
  		return -ENOMEM;
  	}
  
  	vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
  						GFP_KERNEL | __GFP_ZERO);
  	if (!vmcoreinfo_note) {
  		free_page((unsigned long)vmcoreinfo_data);
  		vmcoreinfo_data = NULL;
  		pr_warn("Memory allocation for vmcoreinfo_note failed
  ");
  		return -ENOMEM;
  	}

  	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
  	VMCOREINFO_PAGESIZE(PAGE_SIZE);
  
  	VMCOREINFO_SYMBOL(init_uts_ns);
  	VMCOREINFO_SYMBOL(node_online_map);
  #ifdef CONFIG_MMU
  	VMCOREINFO_SYMBOL(swapper_pg_dir);
  #endif
  	VMCOREINFO_SYMBOL(_stext);
  	VMCOREINFO_SYMBOL(vmap_area_list);
  
  #ifndef CONFIG_NEED_MULTIPLE_NODES
  	VMCOREINFO_SYMBOL(mem_map);
  	VMCOREINFO_SYMBOL(contig_page_data);
  #endif
  #ifdef CONFIG_SPARSEMEM

  	VMCOREINFO_SYMBOL_ARRAY(mem_section);

  	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
  	VMCOREINFO_STRUCT_SIZE(mem_section);
  	VMCOREINFO_OFFSET(mem_section, section_mem_map);
  #endif
  	VMCOREINFO_STRUCT_SIZE(page);
  	VMCOREINFO_STRUCT_SIZE(pglist_data);
  	VMCOREINFO_STRUCT_SIZE(zone);
  	VMCOREINFO_STRUCT_SIZE(free_area);
  	VMCOREINFO_STRUCT_SIZE(list_head);
  	VMCOREINFO_SIZE(nodemask_t);
  	VMCOREINFO_OFFSET(page, flags);
  	VMCOREINFO_OFFSET(page, _refcount);
  	VMCOREINFO_OFFSET(page, mapping);
  	VMCOREINFO_OFFSET(page, lru);
  	VMCOREINFO_OFFSET(page, _mapcount);
  	VMCOREINFO_OFFSET(page, private);
  	VMCOREINFO_OFFSET(page, compound_dtor);
  	VMCOREINFO_OFFSET(page, compound_order);
  	VMCOREINFO_OFFSET(page, compound_head);
  	VMCOREINFO_OFFSET(pglist_data, node_zones);
  	VMCOREINFO_OFFSET(pglist_data, nr_zones);
  #ifdef CONFIG_FLAT_NODE_MEM_MAP
  	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
  #endif
  	VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
  	VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
  	VMCOREINFO_OFFSET(pglist_data, node_id);
  	VMCOREINFO_OFFSET(zone, free_area);
  	VMCOREINFO_OFFSET(zone, vm_stat);
  	VMCOREINFO_OFFSET(zone, spanned_pages);
  	VMCOREINFO_OFFSET(free_area, free_list);
  	VMCOREINFO_OFFSET(list_head, next);
  	VMCOREINFO_OFFSET(list_head, prev);
  	VMCOREINFO_OFFSET(vmap_area, va_start);
  	VMCOREINFO_OFFSET(vmap_area, list);
  	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
  	log_buf_vmcoreinfo_setup();
  	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
  	VMCOREINFO_NUMBER(NR_FREE_PAGES);
  	VMCOREINFO_NUMBER(PG_lru);
  	VMCOREINFO_NUMBER(PG_private);
  	VMCOREINFO_NUMBER(PG_swapcache);
  	VMCOREINFO_NUMBER(PG_slab);
  #ifdef CONFIG_MEMORY_FAILURE
  	VMCOREINFO_NUMBER(PG_hwpoison);
  #endif
  	VMCOREINFO_NUMBER(PG_head_mask);
  	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
  #ifdef CONFIG_HUGETLB_PAGE
  	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
  #endif
  
  	arch_crash_save_vmcoreinfo();
  	update_vmcoreinfo_note();
  
  	return 0;
  }
  
  subsys_initcall(crash_save_vmcoreinfo_init);