/*
   * early_res, could be used to replace bootmem
   */
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/init.h>
  #include <linux/bootmem.h>
  #include <linux/mm.h>

  #include <linux/early_res.h>

  #include <linux/slab.h>
  #include <linux/kmemleak.h>

  
  /*
   * Early reserved memory areas.
   */
  /*
   * need to make sure this one is bigger enough before

   * find_fw_memmap_area could be used

   */
  #define MAX_EARLY_RES_X 32
  
  struct early_res {
  	u64 start, end;
  	char name[15];
  	char overlap_ok;
  };
  static struct early_res early_res_x[MAX_EARLY_RES_X] __initdata;
  
  static int max_early_res __initdata = MAX_EARLY_RES_X;
  static struct early_res *early_res __initdata = &early_res_x[0];
  static int early_res_count __initdata;
  
  static int __init find_overlapped_early(u64 start, u64 end)
  {
  	int i;
  	struct early_res *r;
  
  	for (i = 0; i < max_early_res && early_res[i].end; i++) {
  		r = &early_res[i];
  		if (end > r->start && start < r->end)
  			break;
  	}
  
  	return i;
  }
  
  /*
   * Drop the i-th range from the early reservation map,
   * by copying any higher ranges down one over it, and
   * clearing what had been the last slot.
   */
  static void __init drop_range(int i)
  {
  	int j;
  
  	for (j = i + 1; j < max_early_res && early_res[j].end; j++)
  		;
  
  	memmove(&early_res[i], &early_res[i + 1],
  	       (j - 1 - i) * sizeof(struct early_res));
  
  	early_res[j - 1].end = 0;
  	early_res_count--;
  }

  static void __init drop_range_partial(int i, u64 start, u64 end)
  {
  	u64 common_start, common_end;
  	u64 old_start, old_end;
  
  	old_start = early_res[i].start;
  	old_end = early_res[i].end;
  	common_start = max(old_start, start);
  	common_end = min(old_end, end);
  
  	/* no overlap ? */
  	if (common_start >= common_end)
  		return;
  
  	if (old_start < common_start) {
  		/* make head segment */
  		early_res[i].end = common_start;
  		if (old_end > common_end) {

  			char name[15];
  
  			/*
  			 * Save a local copy of the name, since the
  			 * early_res array could get resized inside
  			 * reserve_early_without_check() ->
  			 * __check_and_double_early_res(), which would
  			 * make the current name pointer invalid.
  			 */
  			strncpy(name, early_res[i].name,
  					 sizeof(early_res[i].name) - 1);

  			/* add another for left over on tail */

  			reserve_early_without_check(common_end, old_end, name);

  		}
  		return;
  	} else {
  		if (old_end > common_end) {
  			/* reuse the entry for tail left */
  			early_res[i].start = common_end;
  			return;
  		}
  		/* all covered */
  		drop_range(i);
  	}
  }

  /*
   * Split any existing ranges that:
   *  1) are marked 'overlap_ok', and
   *  2) overlap with the stated range [start, end)
   * into whatever portion (if any) of the existing range is entirely
   * below or entirely above the stated range.  Drop the portion
   * of the existing range that overlaps with the stated range,
   * which will allow the caller of this routine to then add that
   * stated range without conflicting with any existing range.
   */
  static void __init drop_overlaps_that_are_ok(u64 start, u64 end)
  {
  	int i;
  	struct early_res *r;
  	u64 lower_start, lower_end;
  	u64 upper_start, upper_end;
  	char name[15];
  
  	for (i = 0; i < max_early_res && early_res[i].end; i++) {
  		r = &early_res[i];
  
  		/* Continue past non-overlapping ranges */
  		if (end <= r->start || start >= r->end)
  			continue;
  
  		/*
  		 * Leave non-ok overlaps as is; let caller
  		 * panic "Overlapping early reservations"
  		 * when it hits this overlap.
  		 */
  		if (!r->overlap_ok)
  			return;
  
  		/*
  		 * We have an ok overlap.  We will drop it from the early
  		 * reservation map, and add back in any non-overlapping
  		 * portions (lower or upper) as separate, overlap_ok,
  		 * non-overlapping ranges.
  		 */
  
  		/* 1. Note any non-overlapping (lower or upper) ranges. */
  		strncpy(name, r->name, sizeof(name) - 1);
  
  		lower_start = lower_end = 0;
  		upper_start = upper_end = 0;
  		if (r->start < start) {
  			lower_start = r->start;
  			lower_end = start;
  		}
  		if (r->end > end) {
  			upper_start = end;
  			upper_end = r->end;
  		}
  
  		/* 2. Drop the original ok overlapping range */
  		drop_range(i);
  
  		i--;		/* resume for-loop on copied down entry */
  
  		/* 3. Add back in any non-overlapping ranges. */
  		if (lower_end)
  			reserve_early_overlap_ok(lower_start, lower_end, name);
  		if (upper_end)
  			reserve_early_overlap_ok(upper_start, upper_end, name);
  	}
  }
  
  static void __init __reserve_early(u64 start, u64 end, char *name,
  						int overlap_ok)
  {
  	int i;
  	struct early_res *r;
  
  	i = find_overlapped_early(start, end);
  	if (i >= max_early_res)
  		panic("Too many early reservations");
  	r = &early_res[i];
  	if (r->end)
  		panic("Overlapping early reservations "
  		      "%llx-%llx %s to %llx-%llx %s
  ",
  		      start, end - 1, name ? name : "", r->start,
  		      r->end - 1, r->name);
  	r->start = start;
  	r->end = end;
  	r->overlap_ok = overlap_ok;
  	if (name)
  		strncpy(r->name, name, sizeof(r->name) - 1);
  	early_res_count++;
  }
  
  /*
   * A few early reservtations come here.
   *
   * The 'overlap_ok' in the name of this routine does -not- mean it
   * is ok for these reservations to overlap an earlier reservation.
   * Rather it means that it is ok for subsequent reservations to
   * overlap this one.
   *
   * Use this entry point to reserve early ranges when you are doing
   * so out of "Paranoia", reserving perhaps more memory than you need,
   * just in case, and don't mind a subsequent overlapping reservation
   * that is known to be needed.
   *
   * The drop_overlaps_that_are_ok() call here isn't really needed.
   * It would be needed if we had two colliding 'overlap_ok'
   * reservations, so that the second such would not panic on the
   * overlap with the first.  We don't have any such as of this
   * writing, but might as well tolerate such if it happens in
   * the future.
   */
  void __init reserve_early_overlap_ok(u64 start, u64 end, char *name)
  {
  	drop_overlaps_that_are_ok(start, end);
  	__reserve_early(start, end, name, 1);
  }

  static void __init __check_and_double_early_res(u64 ex_start, u64 ex_end)

  {

  	u64 start, end, size, mem;

  	struct early_res *new;
  
  	/* do we have enough slots left ? */
  	if ((max_early_res - early_res_count) > max(max_early_res/8, 2))
  		return;
  
  	/* double it */

  	mem = -1ULL;

  	size = sizeof(struct early_res) * max_early_res * 2;

  	if (early_res == early_res_x)
  		start = 0;
  	else
  		start = early_res[0].end;
  	end = ex_start;
  	if (start + size < end)

  		mem = find_fw_memmap_area(start, end, size,

  					 sizeof(struct early_res));
  	if (mem == -1ULL) {
  		start = ex_end;

  		end = get_max_mapped();

  		if (start + size < end)

  			mem = find_fw_memmap_area(start, end, size,

  						 sizeof(struct early_res));
  	}

  	if (mem == -1ULL)
  		panic("can not find more space for early_res array");
  
  	new = __va(mem);
  	/* save the first one for own */
  	new[0].start = mem;
  	new[0].end = mem + size;
  	new[0].overlap_ok = 0;
  	/* copy old to new */
  	if (early_res == early_res_x) {
  		memcpy(&new[1], &early_res[0],
  			 sizeof(struct early_res) * max_early_res);
  		memset(&new[max_early_res+1], 0,
  			 sizeof(struct early_res) * (max_early_res - 1));
  		early_res_count++;
  	} else {
  		memcpy(&new[1], &early_res[1],
  			 sizeof(struct early_res) * (max_early_res - 1));
  		memset(&new[max_early_res], 0,
  			 sizeof(struct early_res) * max_early_res);
  	}
  	memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
  	early_res = new;
  	max_early_res *= 2;
  	printk(KERN_DEBUG "early_res array is doubled to %d at [%llx - %llx]
  ",
  		max_early_res, mem, mem + size - 1);
  }
  
  /*
   * Most early reservations come here.
   *
   * We first have drop_overlaps_that_are_ok() drop any pre-existing
   * 'overlap_ok' ranges, so that we can then reserve this memory
   * range without risk of panic'ing on an overlapping overlap_ok
   * early reservation.
   */
  void __init reserve_early(u64 start, u64 end, char *name)
  {
  	if (start >= end)
  		return;

  	__check_and_double_early_res(start, end);

  
  	drop_overlaps_that_are_ok(start, end);
  	__reserve_early(start, end, name, 0);
  }
  
  void __init reserve_early_without_check(u64 start, u64 end, char *name)
  {
  	struct early_res *r;
  
  	if (start >= end)
  		return;

  	__check_and_double_early_res(start, end);

  
  	r = &early_res[early_res_count];
  
  	r->start = start;
  	r->end = end;
  	r->overlap_ok = 0;
  	if (name)
  		strncpy(r->name, name, sizeof(r->name) - 1);
  	early_res_count++;
  }
  
  void __init free_early(u64 start, u64 end)
  {
  	struct early_res *r;
  	int i;

  	kmemleak_free_part(__va(start), end - start);

  	i = find_overlapped_early(start, end);
  	r = &early_res[i];
  	if (i >= max_early_res || r->end != end || r->start != start)
  		panic("free_early on not reserved area: %llx-%llx!",
  			 start, end - 1);
  
  	drop_range(i);
  }

  void __init free_early_partial(u64 start, u64 end)
  {
  	struct early_res *r;
  	int i;

  	kmemleak_free_part(__va(start), end - start);

  	if (start == end)
  		return;
  
  	if (WARN_ONCE(start > end, "  wrong range [%#llx, %#llx]
  ", start, end))
  		return;

  try_next:
  	i = find_overlapped_early(start, end);
  	if (i >= max_early_res)
  		return;
  
  	r = &early_res[i];
  	/* hole ? */
  	if (r->end >= end && r->start <= start) {
  		drop_range_partial(i, start, end);
  		return;
  	}
  
  	drop_range_partial(i, start, end);
  	goto try_next;
  }

  #ifdef CONFIG_NO_BOOTMEM
  static void __init subtract_early_res(struct range *range, int az)
  {
  	int i, count;
  	u64 final_start, final_end;
  	int idx = 0;
  
  	count  = 0;
  	for (i = 0; i < max_early_res && early_res[i].end; i++)
  		count++;
  
  	/* need to skip first one ?*/
  	if (early_res != early_res_x)
  		idx = 1;
  
  #define DEBUG_PRINT_EARLY_RES 1
  
  #if DEBUG_PRINT_EARLY_RES
  	printk(KERN_INFO "Subtract (%d early reservations)
  ", count);
  #endif
  	for (i = idx; i < count; i++) {
  		struct early_res *r = &early_res[i];
  #if DEBUG_PRINT_EARLY_RES
  		printk(KERN_INFO "  #%d [%010llx - %010llx] %15s
  ", i,
  			r->start, r->end, r->name);
  #endif
  		final_start = PFN_DOWN(r->start);
  		final_end = PFN_UP(r->end);
  		if (final_start >= final_end)
  			continue;
  		subtract_range(range, az, final_start, final_end);
  	}
  
  }
  
  int __init get_free_all_memory_range(struct range **rangep, int nodeid)
  {
  	int i, count;
  	u64 start = 0, end;
  	u64 size;
  	u64 mem;
  	struct range *range;
  	int nr_range;
  
  	count  = 0;
  	for (i = 0; i < max_early_res && early_res[i].end; i++)
  		count++;
  
  	count *= 2;
  
  	size = sizeof(struct range) * count;

  	end = get_max_mapped();

  #ifdef MAX_DMA32_PFN

  	if (end > (MAX_DMA32_PFN << PAGE_SHIFT))

  		start = MAX_DMA32_PFN << PAGE_SHIFT;
  #endif

  	mem = find_fw_memmap_area(start, end, size, sizeof(struct range));

  	if (mem == -1ULL)
  		panic("can not find more space for range free");
  
  	range = __va(mem);
  	/* use early_node_map[] and early_res to get range array at first */
  	memset(range, 0, size);
  	nr_range = 0;
  
  	/* need to go over early_node_map to find out good range for node */
  	nr_range = add_from_early_node_map(range, count, nr_range, nodeid);

  #ifdef CONFIG_X86_32
  	subtract_range(range, count, max_low_pfn, -1ULL);
  #endif

  	subtract_early_res(range, count);
  	nr_range = clean_sort_range(range, count);
  
  	/* need to clear it ? */
  	if (nodeid == MAX_NUMNODES) {
  		memset(&early_res[0], 0,
  			 sizeof(struct early_res) * max_early_res);
  		early_res = NULL;
  		max_early_res = 0;
  	}
  
  	*rangep = range;
  	return nr_range;
  }
  #else
  void __init early_res_to_bootmem(u64 start, u64 end)
  {
  	int i, count;
  	u64 final_start, final_end;
  	int idx = 0;
  
  	count  = 0;
  	for (i = 0; i < max_early_res && early_res[i].end; i++)
  		count++;
  
  	/* need to skip first one ?*/
  	if (early_res != early_res_x)
  		idx = 1;
  
  	printk(KERN_INFO "(%d/%d early reservations) ==> bootmem [%010llx - %010llx]
  ",
  			 count - idx, max_early_res, start, end);
  	for (i = idx; i < count; i++) {
  		struct early_res *r = &early_res[i];
  		printk(KERN_INFO "  #%d [%010llx - %010llx] %16s", i,
  			r->start, r->end, r->name);
  		final_start = max(start, r->start);
  		final_end = min(end, r->end);
  		if (final_start >= final_end) {
  			printk(KERN_CONT "
  ");
  			continue;
  		}
  		printk(KERN_CONT " ==> [%010llx - %010llx]
  ",
  			final_start, final_end);
  		reserve_bootmem_generic(final_start, final_end - final_start,
  				BOOTMEM_DEFAULT);
  	}
  	/* clear them */
  	memset(&early_res[0], 0, sizeof(struct early_res) * max_early_res);
  	early_res = NULL;
  	max_early_res = 0;
  	early_res_count = 0;
  }
  #endif
  
  /* Check for already reserved areas */
  static inline int __init bad_addr(u64 *addrp, u64 size, u64 align)
  {
  	int i;
  	u64 addr = *addrp;
  	int changed = 0;
  	struct early_res *r;
  again:
  	i = find_overlapped_early(addr, addr + size);
  	r = &early_res[i];
  	if (i < max_early_res && r->end) {
  		*addrp = addr = round_up(r->end, align);
  		changed = 1;
  		goto again;
  	}
  	return changed;
  }
  
  /* Check for already reserved areas */
  static inline int __init bad_addr_size(u64 *addrp, u64 *sizep, u64 align)
  {
  	int i;
  	u64 addr = *addrp, last;
  	u64 size = *sizep;
  	int changed = 0;
  again:
  	last = addr + size;
  	for (i = 0; i < max_early_res && early_res[i].end; i++) {
  		struct early_res *r = &early_res[i];
  		if (last > r->start && addr < r->start) {
  			size = r->start - addr;
  			changed = 1;
  			goto again;
  		}
  		if (last > r->end && addr < r->end) {
  			addr = round_up(r->end, align);
  			size = last - addr;
  			changed = 1;
  			goto again;
  		}
  		if (last <= r->end && addr >= r->start) {
  			(*sizep)++;
  			return 0;
  		}
  	}
  	if (changed) {
  		*addrp = addr;
  		*sizep = size;
  	}
  	return changed;
  }
  
  /*
   * Find a free area with specified alignment in a specific range.
   * only with the area.between start to end is active range from early_node_map
   * so they are good as RAM
   */
  u64 __init find_early_area(u64 ei_start, u64 ei_last, u64 start, u64 end,
  			 u64 size, u64 align)
  {
  	u64 addr, last;
  
  	addr = round_up(ei_start, align);
  	if (addr < start)
  		addr = round_up(start, align);
  	if (addr >= ei_last)
  		goto out;
  	while (bad_addr(&addr, size, align) && addr+size <= ei_last)
  		;
  	last = addr + size;
  	if (last > ei_last)
  		goto out;
  	if (last > end)
  		goto out;
  
  	return addr;
  
  out:
  	return -1ULL;
  }

  u64 __init find_early_area_size(u64 ei_start, u64 ei_last, u64 start,
  			 u64 *sizep, u64 align)
  {
  	u64 addr, last;
  
  	addr = round_up(ei_start, align);
  	if (addr < start)
  		addr = round_up(start, align);
  	if (addr >= ei_last)
  		goto out;
  	*sizep = ei_last - addr;
  	while (bad_addr_size(&addr, sizep, align) && addr + *sizep <= ei_last)
  		;
  	last = addr + *sizep;
  	if (last > ei_last)
  		goto out;
  
  	return addr;
  
  out:
  	return -1ULL;
  }