FreeBSD/Linux Kernel Cross Reference
sys/mm/memblock.c

     /*
      * Procedures for maintaining information about logical memory blocks.
      *
      * Peter Bergner, IBM Corp.     June 2001.
      * Copyright (C) 2001 Peter Bergner.
      *
      *      This program is free software; you can redistribute it and/or
      *      modify it under the terms of the GNU General Public License
      *      as published by the Free Software Foundation; either version
     *      2 of the License, or (at your option) any later version.
     */
    
    #include <linux/kernel.h>
    #include <linux/slab.h>
    #include <linux/init.h>
    #include <linux/bitops.h>
    #include <linux/poison.h>
    #include <linux/pfn.h>
    #include <linux/debugfs.h>
    #include <linux/seq_file.h>
    #include <linux/memblock.h>
    
    static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
    static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
    
    struct memblock memblock __initdata_memblock = {
            .memory.regions         = memblock_memory_init_regions,
            .memory.cnt             = 1,    /* empty dummy entry */
            .memory.max             = INIT_MEMBLOCK_REGIONS,
    
            .reserved.regions       = memblock_reserved_init_regions,
            .reserved.cnt           = 1,    /* empty dummy entry */
            .reserved.max           = INIT_MEMBLOCK_REGIONS,
    
            .current_limit          = MEMBLOCK_ALLOC_ANYWHERE,
    };
    
    int memblock_debug __initdata_memblock;
    static int memblock_can_resize __initdata_memblock;
    static int memblock_memory_in_slab __initdata_memblock = 0;
    static int memblock_reserved_in_slab __initdata_memblock = 0;
    
    /* inline so we don't get a warning when pr_debug is compiled out */
    static __init_memblock const char *
    memblock_type_name(struct memblock_type *type)
    {
            if (type == &memblock.memory)
                    return "memory";
            else if (type == &memblock.reserved)
                    return "reserved";
            else
                    return "unknown";
    }
    
    /* adjust *@size so that (@base + *@size) doesn't overflow, return new size */
    static inline phys_addr_t memblock_cap_size(phys_addr_t base, phys_addr_t *size)
    {
            return *size = min(*size, (phys_addr_t)ULLONG_MAX - base);
    }
    
    /*
     * Address comparison utilities
     */
    static unsigned long __init_memblock memblock_addrs_overlap(phys_addr_t base1, phys_addr_t size1,
                                           phys_addr_t base2, phys_addr_t size2)
    {
            return ((base1 < (base2 + size2)) && (base2 < (base1 + size1)));
    }
    
    static long __init_memblock memblock_overlaps_region(struct memblock_type *type,
                                            phys_addr_t base, phys_addr_t size)
    {
            unsigned long i;
    
            for (i = 0; i < type->cnt; i++) {
                    phys_addr_t rgnbase = type->regions[i].base;
                    phys_addr_t rgnsize = type->regions[i].size;
                    if (memblock_addrs_overlap(base, size, rgnbase, rgnsize))
                            break;
            }
    
            return (i < type->cnt) ? i : -1;
    }
    
    /**
     * memblock_find_in_range_node - find free area in given range and node
     * @start: start of candidate range
     * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
     * @size: size of free area to find
     * @align: alignment of free area to find
     * @nid: nid of the free area to find, %MAX_NUMNODES for any node
     *
     * Find @size free area aligned to @align in the specified range and node.
     *
     * RETURNS:
     * Found address on success, %0 on failure.
     */
    phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t start,
                                            phys_addr_t end, phys_addr_t size,
                                           phys_addr_t align, int nid)
   {
           phys_addr_t this_start, this_end, cand;
           u64 i;
   
           /* pump up @end */
           if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
                   end = memblock.current_limit;
   
           /* avoid allocating the first page */
           start = max_t(phys_addr_t, start, PAGE_SIZE);
           end = max(start, end);
   
           for_each_free_mem_range_reverse(i, nid, &this_start, &this_end, NULL) {
                   this_start = clamp(this_start, start, end);
                   this_end = clamp(this_end, start, end);
   
                   if (this_end < size)
                           continue;
   
                   cand = round_down(this_end - size, align);
                   if (cand >= this_start)
                           return cand;
           }
           return 0;
   }
   
   /**
    * memblock_find_in_range - find free area in given range
    * @start: start of candidate range
    * @end: end of candidate range, can be %MEMBLOCK_ALLOC_{ANYWHERE|ACCESSIBLE}
    * @size: size of free area to find
    * @align: alignment of free area to find
    *
    * Find @size free area aligned to @align in the specified range.
    *
    * RETURNS:
    * Found address on success, %0 on failure.
    */
   phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
                                           phys_addr_t end, phys_addr_t size,
                                           phys_addr_t align)
   {
           return memblock_find_in_range_node(start, end, size, align,
                                              MAX_NUMNODES);
   }
   
   static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
   {
           type->total_size -= type->regions[r].size;
           memmove(&type->regions[r], &type->regions[r + 1],
                   (type->cnt - (r + 1)) * sizeof(type->regions[r]));
           type->cnt--;
   
           /* Special case for empty arrays */
           if (type->cnt == 0) {
                   WARN_ON(type->total_size != 0);
                   type->cnt = 1;
                   type->regions[0].base = 0;
                   type->regions[0].size = 0;
                   memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
           }
   }
   
   phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info(
                                           phys_addr_t *addr)
   {
           if (memblock.reserved.regions == memblock_reserved_init_regions)
                   return 0;
   
           *addr = __pa(memblock.reserved.regions);
   
           return PAGE_ALIGN(sizeof(struct memblock_region) *
                             memblock.reserved.max);
   }
   
   /**
    * memblock_double_array - double the size of the memblock regions array
    * @type: memblock type of the regions array being doubled
    * @new_area_start: starting address of memory range to avoid overlap with
    * @new_area_size: size of memory range to avoid overlap with
    *
    * Double the size of the @type regions array. If memblock is being used to
    * allocate memory for a new reserved regions array and there is a previously
    * allocated memory range [@new_area_start,@new_area_start+@new_area_size]
    * waiting to be reserved, ensure the memory used by the new array does
    * not overlap.
    *
    * RETURNS:
    * 0 on success, -1 on failure.
    */
   static int __init_memblock memblock_double_array(struct memblock_type *type,
                                                   phys_addr_t new_area_start,
                                                   phys_addr_t new_area_size)
   {
           struct memblock_region *new_array, *old_array;
           phys_addr_t old_alloc_size, new_alloc_size;
           phys_addr_t old_size, new_size, addr;
           int use_slab = slab_is_available();
           int *in_slab;
   
           /* We don't allow resizing until we know about the reserved regions
            * of memory that aren't suitable for allocation
            */
           if (!memblock_can_resize)
                   return -1;
   
           /* Calculate new doubled size */
           old_size = type->max * sizeof(struct memblock_region);
           new_size = old_size << 1;
           /*
            * We need to allocated new one align to PAGE_SIZE,
            *   so we can free them completely later.
            */
           old_alloc_size = PAGE_ALIGN(old_size);
           new_alloc_size = PAGE_ALIGN(new_size);
   
           /* Retrieve the slab flag */
           if (type == &memblock.memory)
                   in_slab = &memblock_memory_in_slab;
           else
                   in_slab = &memblock_reserved_in_slab;
   
           /* Try to find some space for it.
            *
            * WARNING: We assume that either slab_is_available() and we use it or
            * we use MEMBLOCK for allocations. That means that this is unsafe to
            * use when bootmem is currently active (unless bootmem itself is
            * implemented on top of MEMBLOCK which isn't the case yet)
            *
            * This should however not be an issue for now, as we currently only
            * call into MEMBLOCK while it's still active, or much later when slab
            * is active for memory hotplug operations
            */
           if (use_slab) {
                   new_array = kmalloc(new_size, GFP_KERNEL);
                   addr = new_array ? __pa(new_array) : 0;
           } else {
                   /* only exclude range when trying to double reserved.regions */
                   if (type != &memblock.reserved)
                           new_area_start = new_area_size = 0;
   
                   addr = memblock_find_in_range(new_area_start + new_area_size,
                                                   memblock.current_limit,
                                                   new_alloc_size, PAGE_SIZE);
                   if (!addr && new_area_size)
                           addr = memblock_find_in_range(0,
                                   min(new_area_start, memblock.current_limit),
                                   new_alloc_size, PAGE_SIZE);
   
                   new_array = addr ? __va(addr) : NULL;
           }
           if (!addr) {
                   pr_err("memblock: Failed to double %s array from %ld to %ld entries !\n",
                          memblock_type_name(type), type->max, type->max * 2);
                   return -1;
           }
   
           memblock_dbg("memblock: %s is doubled to %ld at [%#010llx-%#010llx]",
                           memblock_type_name(type), type->max * 2, (u64)addr,
                           (u64)addr + new_size - 1);
   
           /*
            * Found space, we now need to move the array over before we add the
            * reserved region since it may be our reserved array itself that is
            * full.
            */
           memcpy(new_array, type->regions, old_size);
           memset(new_array + type->max, 0, old_size);
           old_array = type->regions;
           type->regions = new_array;
           type->max <<= 1;
   
           /* Free old array. We needn't free it if the array is the static one */
           if (*in_slab)
                   kfree(old_array);
           else if (old_array != memblock_memory_init_regions &&
                    old_array != memblock_reserved_init_regions)
                   memblock_free(__pa(old_array), old_alloc_size);
   
           /*
            * Reserve the new array if that comes from the memblock.  Otherwise, we
            * needn't do it
            */
           if (!use_slab)
                   BUG_ON(memblock_reserve(addr, new_alloc_size));
   
           /* Update slab flag */
           *in_slab = use_slab;
   
           return 0;
   }
   
   /**
    * memblock_merge_regions - merge neighboring compatible regions
    * @type: memblock type to scan
    *
    * Scan @type and merge neighboring compatible regions.
    */
   static void __init_memblock memblock_merge_regions(struct memblock_type *type)
   {
           int i = 0;
   
           /* cnt never goes below 1 */
           while (i < type->cnt - 1) {
                   struct memblock_region *this = &type->regions[i];
                   struct memblock_region *next = &type->regions[i + 1];
   
                   if (this->base + this->size != next->base ||
                       memblock_get_region_node(this) !=
                       memblock_get_region_node(next)) {
                           BUG_ON(this->base + this->size > next->base);
                           i++;
                           continue;
                   }
   
                   this->size += next->size;
                   /* move forward from next + 1, index of which is i + 2 */
                   memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
                   type->cnt--;
           }
   }
   
   /**
    * memblock_insert_region - insert new memblock region
    * @type: memblock type to insert into
    * @idx: index for the insertion point
    * @base: base address of the new region
    * @size: size of the new region
    *
    * Insert new memblock region [@base,@base+@size) into @type at @idx.
    * @type must already have extra room to accomodate the new region.
    */
   static void __init_memblock memblock_insert_region(struct memblock_type *type,
                                                      int idx, phys_addr_t base,
                                                      phys_addr_t size, int nid)
   {
           struct memblock_region *rgn = &type->regions[idx];
   
           BUG_ON(type->cnt >= type->max);
           memmove(rgn + 1, rgn, (type->cnt - idx) * sizeof(*rgn));
           rgn->base = base;
           rgn->size = size;
           memblock_set_region_node(rgn, nid);
           type->cnt++;
           type->total_size += size;
   }
   
   /**
    * memblock_add_region - add new memblock region
    * @type: memblock type to add new region into
    * @base: base address of the new region
    * @size: size of the new region
    * @nid: nid of the new region
    *
    * Add new memblock region [@base,@base+@size) into @type.  The new region
    * is allowed to overlap with existing ones - overlaps don't affect already
    * existing regions.  @type is guaranteed to be minimal (all neighbouring
    * compatible regions are merged) after the addition.
    *
    * RETURNS:
    * 0 on success, -errno on failure.
    */
   static int __init_memblock memblock_add_region(struct memblock_type *type,
                                   phys_addr_t base, phys_addr_t size, int nid)
   {
           bool insert = false;
           phys_addr_t obase = base;
           phys_addr_t end = base + memblock_cap_size(base, &size);
           int i, nr_new;
   
           if (!size)
                   return 0;
   
           /* special case for empty array */
           if (type->regions[0].size == 0) {
                   WARN_ON(type->cnt != 1 || type->total_size);
                   type->regions[0].base = base;
                   type->regions[0].size = size;
                   memblock_set_region_node(&type->regions[0], nid);
                   type->total_size = size;
                   return 0;
           }
   repeat:
           /*
            * The following is executed twice.  Once with %false @insert and
            * then with %true.  The first counts the number of regions needed
            * to accomodate the new area.  The second actually inserts them.
            */
           base = obase;
           nr_new = 0;
   
           for (i = 0; i < type->cnt; i++) {
                   struct memblock_region *rgn = &type->regions[i];
                   phys_addr_t rbase = rgn->base;
                   phys_addr_t rend = rbase + rgn->size;
   
                   if (rbase >= end)
                           break;
                   if (rend <= base)
                           continue;
                   /*
                    * @rgn overlaps.  If it separates the lower part of new
                    * area, insert that portion.
                    */
                   if (rbase > base) {
                           nr_new++;
                           if (insert)
                                   memblock_insert_region(type, i++, base,
                                                          rbase - base, nid);
                   }
                   /* area below @rend is dealt with, forget about it */
                   base = min(rend, end);
           }
   
           /* insert the remaining portion */
           if (base < end) {
                   nr_new++;
                   if (insert)
                           memblock_insert_region(type, i, base, end - base, nid);
           }
   
           /*
            * If this was the first round, resize array and repeat for actual
            * insertions; otherwise, merge and return.
            */
           if (!insert) {
                   while (type->cnt + nr_new > type->max)
                           if (memblock_double_array(type, obase, size) < 0)
                                   return -ENOMEM;
                   insert = true;
                   goto repeat;
           } else {
                   memblock_merge_regions(type);
                   return 0;
           }
   }
   
   int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
                                          int nid)
   {
           return memblock_add_region(&memblock.memory, base, size, nid);
   }
   
   int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
   {
           return memblock_add_region(&memblock.memory, base, size, MAX_NUMNODES);
   }
   
   /**
    * memblock_isolate_range - isolate given range into disjoint memblocks
    * @type: memblock type to isolate range for
    * @base: base of range to isolate
    * @size: size of range to isolate
    * @start_rgn: out parameter for the start of isolated region
    * @end_rgn: out parameter for the end of isolated region
    *
    * Walk @type and ensure that regions don't cross the boundaries defined by
    * [@base,@base+@size).  Crossing regions are split at the boundaries,
    * which may create at most two more regions.  The index of the first
    * region inside the range is returned in *@start_rgn and end in *@end_rgn.
    *
    * RETURNS:
    * 0 on success, -errno on failure.
    */
   static int __init_memblock memblock_isolate_range(struct memblock_type *type,
                                           phys_addr_t base, phys_addr_t size,
                                           int *start_rgn, int *end_rgn)
   {
           phys_addr_t end = base + memblock_cap_size(base, &size);
           int i;
   
           *start_rgn = *end_rgn = 0;
   
           if (!size)
                   return 0;
   
           /* we'll create at most two more regions */
           while (type->cnt + 2 > type->max)
                   if (memblock_double_array(type, base, size) < 0)
                           return -ENOMEM;
   
           for (i = 0; i < type->cnt; i++) {
                   struct memblock_region *rgn = &type->regions[i];
                   phys_addr_t rbase = rgn->base;
                   phys_addr_t rend = rbase + rgn->size;
   
                   if (rbase >= end)
                           break;
                   if (rend <= base)
                           continue;
   
                   if (rbase < base) {
                           /*
                            * @rgn intersects from below.  Split and continue
                            * to process the next region - the new top half.
                            */
                           rgn->base = base;
                           rgn->size -= base - rbase;
                           type->total_size -= base - rbase;
                           memblock_insert_region(type, i, rbase, base - rbase,
                                                  memblock_get_region_node(rgn));
                   } else if (rend > end) {
                           /*
                            * @rgn intersects from above.  Split and redo the
                            * current region - the new bottom half.
                            */
                           rgn->base = end;
                           rgn->size -= end - rbase;
                           type->total_size -= end - rbase;
                           memblock_insert_region(type, i--, rbase, end - rbase,
                                                  memblock_get_region_node(rgn));
                   } else {
                           /* @rgn is fully contained, record it */
                           if (!*end_rgn)
                                   *start_rgn = i;
                           *end_rgn = i + 1;
                   }
           }
   
           return 0;
   }
   
   static int __init_memblock __memblock_remove(struct memblock_type *type,
                                                phys_addr_t base, phys_addr_t size)
   {
           int start_rgn, end_rgn;
           int i, ret;
   
           ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
           if (ret)
                   return ret;
   
           for (i = end_rgn - 1; i >= start_rgn; i--)
                   memblock_remove_region(type, i);
           return 0;
   }
   
   int __init_memblock memblock_remove(phys_addr_t base, phys_addr_t size)
   {
           return __memblock_remove(&memblock.memory, base, size);
   }
   
   int __init_memblock memblock_free(phys_addr_t base, phys_addr_t size)
   {
           memblock_dbg("   memblock_free: [%#016llx-%#016llx] %pF\n",
                        (unsigned long long)base,
                        (unsigned long long)base + size,
                        (void *)_RET_IP_);
   
           return __memblock_remove(&memblock.reserved, base, size);
   }
   
   int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
   {
           struct memblock_type *_rgn = &memblock.reserved;
   
           memblock_dbg("memblock_reserve: [%#016llx-%#016llx] %pF\n",
                        (unsigned long long)base,
                        (unsigned long long)base + size,
                        (void *)_RET_IP_);
   
           return memblock_add_region(_rgn, base, size, MAX_NUMNODES);
   }
   
   /**
    * __next_free_mem_range - next function for for_each_free_mem_range()
    * @idx: pointer to u64 loop variable
    * @nid: nid: node selector, %MAX_NUMNODES for all nodes
    * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
    * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
    * @out_nid: ptr to int for nid of the range, can be %NULL
    *
    * Find the first free area from *@idx which matches @nid, fill the out
    * parameters, and update *@idx for the next iteration.  The lower 32bit of
    * *@idx contains index into memory region and the upper 32bit indexes the
    * areas before each reserved region.  For example, if reserved regions
    * look like the following,
    *
    *      0:[0-16), 1:[32-48), 2:[128-130)
    *
    * The upper 32bit indexes the following regions.
    *
    *      0:[0-0), 1:[16-32), 2:[48-128), 3:[130-MAX)
    *
    * As both region arrays are sorted, the function advances the two indices
    * in lockstep and returns each intersection.
    */
   void __init_memblock __next_free_mem_range(u64 *idx, int nid,
                                              phys_addr_t *out_start,
                                              phys_addr_t *out_end, int *out_nid)
   {
           struct memblock_type *mem = &memblock.memory;
           struct memblock_type *rsv = &memblock.reserved;
           int mi = *idx & 0xffffffff;
           int ri = *idx >> 32;
   
           for ( ; mi < mem->cnt; mi++) {
                   struct memblock_region *m = &mem->regions[mi];
                   phys_addr_t m_start = m->base;
                   phys_addr_t m_end = m->base + m->size;
   
                   /* only memory regions are associated with nodes, check it */
                   if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
                           continue;
   
                   /* scan areas before each reservation for intersection */
                   for ( ; ri < rsv->cnt + 1; ri++) {
                           struct memblock_region *r = &rsv->regions[ri];
                           phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
                           phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
   
                           /* if ri advanced past mi, break out to advance mi */
                           if (r_start >= m_end)
                                   break;
                           /* if the two regions intersect, we're done */
                           if (m_start < r_end) {
                                   if (out_start)
                                           *out_start = max(m_start, r_start);
                                   if (out_end)
                                           *out_end = min(m_end, r_end);
                                   if (out_nid)
                                           *out_nid = memblock_get_region_node(m);
                                   /*
                                    * The region which ends first is advanced
                                    * for the next iteration.
                                    */
                                   if (m_end <= r_end)
                                           mi++;
                                   else
                                           ri++;
                                   *idx = (u32)mi | (u64)ri << 32;
                                   return;
                           }
                   }
           }
   
           /* signal end of iteration */
           *idx = ULLONG_MAX;
   }
   
   /**
    * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse()
    * @idx: pointer to u64 loop variable
    * @nid: nid: node selector, %MAX_NUMNODES for all nodes
    * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL
    * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL
    * @out_nid: ptr to int for nid of the range, can be %NULL
    *
    * Reverse of __next_free_mem_range().
    */
   void __init_memblock __next_free_mem_range_rev(u64 *idx, int nid,
                                              phys_addr_t *out_start,
                                              phys_addr_t *out_end, int *out_nid)
   {
           struct memblock_type *mem = &memblock.memory;
           struct memblock_type *rsv = &memblock.reserved;
           int mi = *idx & 0xffffffff;
           int ri = *idx >> 32;
   
           if (*idx == (u64)ULLONG_MAX) {
                   mi = mem->cnt - 1;
                   ri = rsv->cnt;
           }
   
           for ( ; mi >= 0; mi--) {
                   struct memblock_region *m = &mem->regions[mi];
                   phys_addr_t m_start = m->base;
                   phys_addr_t m_end = m->base + m->size;
   
                   /* only memory regions are associated with nodes, check it */
                   if (nid != MAX_NUMNODES && nid != memblock_get_region_node(m))
                           continue;
   
                   /* scan areas before each reservation for intersection */
                   for ( ; ri >= 0; ri--) {
                           struct memblock_region *r = &rsv->regions[ri];
                           phys_addr_t r_start = ri ? r[-1].base + r[-1].size : 0;
                           phys_addr_t r_end = ri < rsv->cnt ? r->base : ULLONG_MAX;
   
                           /* if ri advanced past mi, break out to advance mi */
                           if (r_end <= m_start)
                                   break;
                           /* if the two regions intersect, we're done */
                           if (m_end > r_start) {
                                   if (out_start)
                                           *out_start = max(m_start, r_start);
                                   if (out_end)
                                           *out_end = min(m_end, r_end);
                                   if (out_nid)
                                           *out_nid = memblock_get_region_node(m);
   
                                   if (m_start >= r_start)
                                           mi--;
                                   else
                                           ri--;
                                   *idx = (u32)mi | (u64)ri << 32;
                                   return;
                           }
                   }
           }
   
           *idx = ULLONG_MAX;
   }
   
   #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
   /*
    * Common iterator interface used to define for_each_mem_range().
    */
   void __init_memblock __next_mem_pfn_range(int *idx, int nid,
                                   unsigned long *out_start_pfn,
                                   unsigned long *out_end_pfn, int *out_nid)
   {
           struct memblock_type *type = &memblock.memory;
           struct memblock_region *r;
   
           while (++*idx < type->cnt) {
                   r = &type->regions[*idx];
   
                   if (PFN_UP(r->base) >= PFN_DOWN(r->base + r->size))
                           continue;
                   if (nid == MAX_NUMNODES || nid == r->nid)
                           break;
           }
           if (*idx >= type->cnt) {
                   *idx = -1;
                   return;
           }
   
           if (out_start_pfn)
                   *out_start_pfn = PFN_UP(r->base);
           if (out_end_pfn)
                   *out_end_pfn = PFN_DOWN(r->base + r->size);
           if (out_nid)
                   *out_nid = r->nid;
   }
   
   /**
    * memblock_set_node - set node ID on memblock regions
    * @base: base of area to set node ID for
    * @size: size of area to set node ID for
    * @nid: node ID to set
    *
    * Set the nid of memblock memory regions in [@base,@base+@size) to @nid.
    * Regions which cross the area boundaries are split as necessary.
    *
    * RETURNS:
    * 0 on success, -errno on failure.
    */
   int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
                                         int nid)
   {
           struct memblock_type *type = &memblock.memory;
           int start_rgn, end_rgn;
           int i, ret;
   
           ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
           if (ret)
                   return ret;
   
           for (i = start_rgn; i < end_rgn; i++)
                   memblock_set_region_node(&type->regions[i], nid);
   
           memblock_merge_regions(type);
           return 0;
   }
   #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
   
   static phys_addr_t __init memblock_alloc_base_nid(phys_addr_t size,
                                           phys_addr_t align, phys_addr_t max_addr,
                                           int nid)
   {
           phys_addr_t found;
   
           /* align @size to avoid excessive fragmentation on reserved array */
           size = round_up(size, align);
   
           found = memblock_find_in_range_node(0, max_addr, size, align, nid);
           if (found && !memblock_reserve(found, size))
                   return found;
   
           return 0;
   }
   
   phys_addr_t __init memblock_alloc_nid(phys_addr_t size, phys_addr_t align, int nid)
   {
           return memblock_alloc_base_nid(size, align, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
   }
   
   phys_addr_t __init __memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
   {
           return memblock_alloc_base_nid(size, align, max_addr, MAX_NUMNODES);
   }
   
   phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
   {
           phys_addr_t alloc;
   
           alloc = __memblock_alloc_base(size, align, max_addr);
   
           if (alloc == 0)
                   panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
                         (unsigned long long) size, (unsigned long long) max_addr);
   
           return alloc;
   }
   
   phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
   {
           return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
   }
   
   phys_addr_t __init memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
   {
           phys_addr_t res = memblock_alloc_nid(size, align, nid);
   
           if (res)
                   return res;
           return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
   }
   
   
   /*
    * Remaining API functions
    */
   
   phys_addr_t __init memblock_phys_mem_size(void)
   {
           return memblock.memory.total_size;
   }
   
   /* lowest address */
   phys_addr_t __init_memblock memblock_start_of_DRAM(void)
   {
           return memblock.memory.regions[0].base;
   }
   
   phys_addr_t __init_memblock memblock_end_of_DRAM(void)
   {
           int idx = memblock.memory.cnt - 1;
   
           return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size);
   }
   
   void __init memblock_enforce_memory_limit(phys_addr_t limit)
   {
           unsigned long i;
           phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX;
   
           if (!limit)
                   return;
   
           /* find out max address */
           for (i = 0; i < memblock.memory.cnt; i++) {
                   struct memblock_region *r = &memblock.memory.regions[i];
   
                   if (limit <= r->size) {
                           max_addr = r->base + limit;
                           break;
                   }
                   limit -= r->size;
           }
   
           /* truncate both memory and reserved regions */
           __memblock_remove(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX);
           __memblock_remove(&memblock.reserved, max_addr, (phys_addr_t)ULLONG_MAX);
   }
   
   static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr)
   {
           unsigned int left = 0, right = type->cnt;
   
           do {
                   unsigned int mid = (right + left) / 2;
   
                   if (addr < type->regions[mid].base)
                           right = mid;
                   else if (addr >= (type->regions[mid].base +
                                     type->regions[mid].size))
                           left = mid + 1;
                   else
                           return mid;
           } while (left < right);
           return -1;
   }
   
   int __init memblock_is_reserved(phys_addr_t addr)
   {
           return memblock_search(&memblock.reserved, addr) != -1;
   }
   
   int __init_memblock memblock_is_memory(phys_addr_t addr)
   {
           return memblock_search(&memblock.memory, addr) != -1;
   }
   
   /**
    * memblock_is_region_memory - check if a region is a subset of memory
    * @base: base of region to check
    * @size: size of region to check
    *
    * Check if the region [@base, @base+@size) is a subset of a memory block.
    *
    * RETURNS:
    * 0 if false, non-zero if true
    */
   int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size)
   {
           int idx = memblock_search(&memblock.memory, base);
           phys_addr_t end = base + memblock_cap_size(base, &size);
   
           if (idx == -1)
                   return 0;
           return memblock.memory.regions[idx].base <= base &&
                   (memblock.memory.regions[idx].base +
                    memblock.memory.regions[idx].size) >= end;
   }
   
   /**
    * memblock_is_region_reserved - check if a region intersects reserved memory
    * @base: base of region to check
    * @size: size of region to check
    *
    * Check if the region [@base, @base+@size) intersects a reserved memory block.
    *
    * RETURNS:
    * 0 if false, non-zero if true
    */
   int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
   {
           memblock_cap_size(base, &size);
           return memblock_overlaps_region(&memblock.reserved, base, size) >= 0;
   }
   
   void __init_memblock memblock_trim_memory(phys_addr_t align)
   {
           int i;
           phys_addr_t start, end, orig_start, orig_end;
           struct memblock_type *mem = &memblock.memory;
   
           for (i = 0; i < mem->cnt; i++) {
                   orig_start = mem->regions[i].base;
                   orig_end = mem->regions[i].base + mem->regions[i].size;
                   start = round_up(orig_start, align);
                   end = round_down(orig_end, align);
   
                   if (start == orig_start && end == orig_end)
                           continue;
   
                   if (start < end) {
                           mem->regions[i].base = start;
                           mem->regions[i].size = end - start;
                   } else {
                           memblock_remove_region(mem, i);
                           i--;
                   }
           }
   }
   
   void __init_memblock memblock_set_current_limit(phys_addr_t limit)
   {
           memblock.current_limit = limit;
   }
   
   static void __init_memblock memblock_dump(struct memblock_type *type, char *name)
   {
           unsigned long long base, size;
           int i;
   
           pr_info(" %s.cnt  = 0x%lx\n", name, type->cnt);
   
           for (i = 0; i < type->cnt; i++) {
                   struct memblock_region *rgn = &type->regions[i];
                   char nid_buf[32] = "";
   
                   base = rgn->base;
                   size = rgn->size;
   #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
                   if (memblock_get_region_node(rgn) != MAX_NUMNODES)
                           snprintf(nid_buf, sizeof(nid_buf), " on node %d",
                                    memblock_get_region_node(rgn));
   #endif
                   pr_info(" %s[%#x]\t[%#016llx-%#016llx], %#llx bytes%s\n",
                           name, i, base, base + size - 1, size, nid_buf);
           }
   }
   
   void __init_memblock __memblock_dump_all(void)
   {
           pr_info("MEMBLOCK configuration:\n");
           pr_info(" memory size = %#llx reserved size = %#llx\n",
                   (unsigned long long)memblock.memory.total_size,
                   (unsigned long long)memblock.reserved.total_size);
   
           memblock_dump(&memblock.memory, "memory");
           memblock_dump(&memblock.reserved, "reserved");
   }
   
   void __init memblock_allow_resize(void)
   {
          memblock_can_resize = 1;
  }
  
  static int __init early_memblock(char *p)
  {
          if (p && strstr(p, "debug"))
                  memblock_debug = 1;
          return 0;
  }
  early_param("memblock", early_memblock);
  
  #if defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK)
  
  static int memblock_debug_show(struct seq_file *m, void *private)
  {
          struct memblock_type *type = m->private;
          struct memblock_region *reg;
          int i;
  
          for (i = 0; i < type->cnt; i++) {
                  reg = &type->regions[i];
                  seq_printf(m, "%4d: ", i);
                  if (sizeof(phys_addr_t) == 4)
                          seq_printf(m, "0x%08lx..0x%08lx\n",
                                     (unsigned long)reg->base,
                                     (unsigned long)(reg->base + reg->size - 1));
                  else
                          seq_printf(m, "0x%016llx..0x%016llx\n",
                                     (unsigned long long)reg->base,
                                     (unsigned long long)(reg->base + reg->size - 1));
  
          }
          return 0;
  }
  
  static int memblock_debug_open(struct inode *inode, struct file *file)
  {
          return single_open(file, memblock_debug_show, inode->i_private);
  }
  
  static const struct file_operations memblock_debug_fops = {
          .open = memblock_debug_open,
          .read = seq_read,
          .llseek = seq_lseek,
          .release = single_release,
  };
  
  static int __init memblock_init_debugfs(void)
  {
          struct dentry *root = debugfs_create_dir("memblock", NULL);
          if (!root)
                  return -ENXIO;
          debugfs_create_file("memory", S_IRUGO, root, &memblock.memory, &memblock_debug_fops);
          debugfs_create_file("reserved", S_IRUGO, root, &memblock.reserved, &memblock_debug_fops);
  
          return 0;
  }
  __initcall(memblock_init_debugfs);
  
  #endif /* CONFIG_DEBUG_FS */

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