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 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Procedures for maintaining information about logical memory blocks.
  *
  * Peter Bergner, IBM Corp. June 2001.
  * Copyright (C) 2001 Peter Bergner.
  */
 
 #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/kmemleak.h>
 #include <linux/seq_file.h>
 #include <linux/memblock.h>
 
 #include <asm/sections.h>
 #include <linux/io.h>
 
 #include "internal.h"
 
 #define INIT_MEMBLOCK_REGIONS           128
 #define INIT_PHYSMEM_REGIONS            4
 
 #ifndef INIT_MEMBLOCK_RESERVED_REGIONS
 # define INIT_MEMBLOCK_RESERVED_REGIONS     INIT_MEMBLOCK_REGIONS
 #endif
 
 #ifndef INIT_MEMBLOCK_MEMORY_REGIONS
 #define INIT_MEMBLOCK_MEMORY_REGIONS        INIT_MEMBLOCK_REGIONS
 #endif
 
 /**
  * DOC: memblock overview
  *
  * Memblock is a method of managing memory regions during the early
  * boot period when the usual kernel memory allocators are not up and
  * running.
  *
  * Memblock views the system memory as collections of contiguous
  * regions. There are several types of these collections:
  *
  * * ``memory`` - describes the physical memory available to the
  *   kernel; this may differ from the actual physical memory installed
  *   in the system, for instance when the memory is restricted with
  *   ``mem=`` command line parameter
  * * ``reserved`` - describes the regions that were allocated
  * * ``physmem`` - describes the actual physical memory available during
  *   boot regardless of the possible restrictions and memory hot(un)plug;
  *   the ``physmem`` type is only available on some architectures.
  *
  * Each region is represented by struct memblock_region that
  * defines the region extents, its attributes and NUMA node id on NUMA
  * systems. Every memory type is described by the struct memblock_type
  * which contains an array of memory regions along with
  * the allocator metadata. The "memory" and "reserved" types are nicely
  * wrapped with struct memblock. This structure is statically
  * initialized at build time. The region arrays are initially sized to
  * %INIT_MEMBLOCK_MEMORY_REGIONS for "memory" and
  * %INIT_MEMBLOCK_RESERVED_REGIONS for "reserved". The region array
  * for "physmem" is initially sized to %INIT_PHYSMEM_REGIONS.
  * The memblock_allow_resize() enables automatic resizing of the region
  * arrays during addition of new regions. This feature should be used
  * with care so that memory allocated for the region array will not
  * overlap with areas that should be reserved, for example initrd.
  *
  * The early architecture setup should tell memblock what the physical
  * memory layout is by using memblock_add() or memblock_add_node()
  * functions. The first function does not assign the region to a NUMA
  * node and it is appropriate for UMA systems. Yet, it is possible to
  * use it on NUMA systems as well and assign the region to a NUMA node
  * later in the setup process using memblock_set_node(). The
  * memblock_add_node() performs such an assignment directly.
  *
  * Once memblock is setup the memory can be allocated using one of the
  * API variants:
  *
  * * memblock_phys_alloc*() - these functions return the **physical**
  *   address of the allocated memory
  * * memblock_alloc*() - these functions return the **virtual** address
  *   of the allocated memory.
  *
  * Note, that both API variants use implicit assumptions about allowed
  * memory ranges and the fallback methods. Consult the documentation
  * of memblock_alloc_internal() and memblock_alloc_range_nid()
  * functions for more elaborate description.
  *
  * As the system boot progresses, the architecture specific mem_init()
  * function frees all the memory to the buddy page allocator.
  *
  * Unless an architecture enables %CONFIG_ARCH_KEEP_MEMBLOCK, the
  * memblock data structures (except "physmem") will be discarded after the
  * system initialization completes.
  */
 
 #ifndef CONFIG_NUMA
 struct pglist_data __refdata contig_page_data;
 EXPORT_SYMBOL(contig_page_data);
 #endif
 
 unsigned long max_low_pfn;
 unsigned long min_low_pfn;
 unsigned long max_pfn;
 unsigned long long max_possible_pfn;
 
 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_MEMORY_REGIONS] __initdata_memblock;
 static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
 static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS];
 #endif
 
 struct memblock memblock __initdata_memblock = {
     .memory.regions     = memblock_memory_init_regions,
     .memory.cnt     = 1,    /* empty dummy entry */
     .memory.max     = INIT_MEMBLOCK_MEMORY_REGIONS,
     .memory.name        = "memory",
 
     .reserved.regions   = memblock_reserved_init_regions,
     .reserved.cnt       = 1,    /* empty dummy entry */
     .reserved.max       = INIT_MEMBLOCK_RESERVED_REGIONS,
     .reserved.name      = "reserved",
 
     .bottom_up      = false,
     .current_limit      = MEMBLOCK_ALLOC_ANYWHERE,
 };
 
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
 struct memblock_type physmem = {
     .regions        = memblock_physmem_init_regions,
     .cnt            = 1,    /* empty dummy entry */
     .max            = INIT_PHYSMEM_REGIONS,
     .name           = "physmem",
 };
 #endif
 
 /*
  * keep a pointer to &memblock.memory in the text section to use it in
  * __next_mem_range() and its helpers.
  *  For architectures that do not keep memblock data after init, this
  * pointer will be reset to NULL at memblock_discard()
  */
 static __refdata struct memblock_type *memblock_memory = &memblock.memory;
 
 #define for_each_memblock_type(i, memblock_type, rgn)           \
     for (i = 0, rgn = &memblock_type->regions[0];           \
          i < memblock_type->cnt;                    \
          i++, rgn = &memblock_type->regions[i])
 
 #define memblock_dbg(fmt, ...)                      \
     do {                                \
         if (memblock_debug)                 \
             pr_info(fmt, ##__VA_ARGS__);            \
     } while (0)
 
 static int memblock_debug __initdata_memblock;
 static bool system_has_some_mirror __initdata_memblock = false;
 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;
 
 static enum memblock_flags __init_memblock choose_memblock_flags(void)
 {
     return system_has_some_mirror ? MEMBLOCK_MIRROR : MEMBLOCK_NONE;
 }
 
 /* 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_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)));
 }
 
 bool __init_memblock memblock_overlaps_region(struct memblock_type *type,
                     phys_addr_t base, phys_addr_t size)
 {
     unsigned long i;
 
     memblock_cap_size(base, &size);
 
     for (i = 0; i < type->cnt; i++)
         if (memblock_addrs_overlap(base, size, type->regions[i].base,
                        type->regions[i].size))
             break;
     return i < type->cnt;
 }
 
 /**
  * __memblock_find_range_bottom_up - find free area utility in bottom-up
  * @start: start of candidate range
  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
  *       %MEMBLOCK_ALLOC_ACCESSIBLE
  * @size: size of free area to find
  * @align: alignment of free area to find
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  * @flags: pick from blocks based on memory attributes
  *
  * Utility called from memblock_find_in_range_node(), find free area bottom-up.
  *
  * Return:
  * Found address on success, 0 on failure.
  */
 static phys_addr_t __init_memblock
 __memblock_find_range_bottom_up(phys_addr_t start, phys_addr_t end,
                 phys_addr_t size, phys_addr_t align, int nid,
                 enum memblock_flags flags)
 {
     phys_addr_t this_start, this_end, cand;
     u64 i;
 
     for_each_free_mem_range(i, nid, flags, &this_start, &this_end, NULL) {
         this_start = clamp(this_start, start, end);
         this_end = clamp(this_end, start, end);
 
         cand = round_up(this_start, align);
         if (cand < this_end && this_end - cand >= size)
             return cand;
     }
 
     return 0;
 }
 
 /**
  * __memblock_find_range_top_down - find free area utility, in top-down
  * @start: start of candidate range
  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
  *       %MEMBLOCK_ALLOC_ACCESSIBLE
  * @size: size of free area to find
  * @align: alignment of free area to find
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  * @flags: pick from blocks based on memory attributes
  *
  * Utility called from memblock_find_in_range_node(), find free area top-down.
  *
  * Return:
  * Found address on success, 0 on failure.
  */
 static phys_addr_t __init_memblock
 __memblock_find_range_top_down(phys_addr_t start, phys_addr_t end,
                    phys_addr_t size, phys_addr_t align, int nid,
                    enum memblock_flags flags)
 {
     phys_addr_t this_start, this_end, cand;
     u64 i;
 
     for_each_free_mem_range_reverse(i, nid, flags, &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_node - find free area in given range and node
  * @size: size of free area to find
  * @align: alignment of free area to find
  * @start: start of candidate range
  * @end: end of candidate range, can be %MEMBLOCK_ALLOC_ANYWHERE or
  *       %MEMBLOCK_ALLOC_ACCESSIBLE
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  * @flags: pick from blocks based on memory attributes
  *
  * Find @size free area aligned to @align in the specified range and node.
  *
  * Return:
  * Found address on success, 0 on failure.
  */
 static phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,
                     phys_addr_t align, phys_addr_t start,
                     phys_addr_t end, int nid,
                     enum memblock_flags flags)
 {
     /* pump up @end */
     if (end == MEMBLOCK_ALLOC_ACCESSIBLE ||
         end == MEMBLOCK_ALLOC_NOLEAKTRACE)
         end = memblock.current_limit;
 
     /* avoid allocating the first page */
     start = max_t(phys_addr_t, start, PAGE_SIZE);
     end = max(start, end);
 
     if (memblock_bottom_up())
         return __memblock_find_range_bottom_up(start, end, size, align,
                                nid, flags);
     else
         return __memblock_find_range_top_down(start, end, size, align,
                               nid, flags);
 }
 
 /**
  * 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 or
  *       %MEMBLOCK_ALLOC_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.
  *
  * Return:
  * Found address on success, 0 on failure.
  */
 static 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)
 {
     phys_addr_t ret;
     enum memblock_flags flags = choose_memblock_flags();
 
 again:
     ret = memblock_find_in_range_node(size, align, start, end,
                         NUMA_NO_NODE, flags);
 
     if (!ret && (flags & MEMBLOCK_MIRROR)) {
         pr_warn_ratelimited("Could not allocate %pap bytes of mirrored memory\n",
             &size);
         flags &= ~MEMBLOCK_MIRROR;
         goto again;
     }
 
     return ret;
 }
 
 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;
         type->regions[0].flags = 0;
         memblock_set_region_node(&type->regions[0], MAX_NUMNODES);
     }
 }
 
 #ifndef CONFIG_ARCH_KEEP_MEMBLOCK
 /**
  * memblock_discard - discard memory and reserved arrays if they were allocated
  */
 void __init memblock_discard(void)
 {
     phys_addr_t addr, size;
 
     if (memblock.reserved.regions != memblock_reserved_init_regions) {
         addr = __pa(memblock.reserved.regions);
         size = PAGE_ALIGN(sizeof(struct memblock_region) *
                   memblock.reserved.max);
         if (memblock_reserved_in_slab)
             kfree(memblock.reserved.regions);
         else
             memblock_free_late(addr, size);
     }
 
     if (memblock.memory.regions != memblock_memory_init_regions) {
         addr = __pa(memblock.memory.regions);
         size = PAGE_ALIGN(sizeof(struct memblock_region) *
                   memblock.memory.max);
         if (memblock_memory_in_slab)
             kfree(memblock.memory.regions);
         else
             memblock_free_late(addr, size);
     }
 
     memblock_memory = NULL;
 }
 #endif
 
 /**
  * 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.
  *
  * Return:
  * 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, new_end;
     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 */
     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",
                type->name, type->max, type->max * 2);
         return -1;
     }
 
     new_end = addr + new_size - 1;
     memblock_dbg("memblock: %s is doubled to %ld at [%pa-%pa]",
             type->name, type->max * 2, &addr, &new_end);
 
     /*
      * 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(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) ||
             this->flags != next->flags) {
             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
  * @nid:    node id of the new region
  * @flags:  flags of the new region
  *
  * Insert new memblock region [@base, @base + @size) into @type at @idx.
  * @type must already have extra room to accommodate 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,
                            enum memblock_flags flags)
 {
     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;
     rgn->flags = flags;
     memblock_set_region_node(rgn, nid);
     type->cnt++;
     type->total_size += size;
 }
 
 /**
  * memblock_add_range - 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
  * @flags: flags 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.
  *
  * Return:
  * 0 on success, -errno on failure.
  */
 static int __init_memblock memblock_add_range(struct memblock_type *type,
                 phys_addr_t base, phys_addr_t size,
                 int nid, enum memblock_flags flags)
 {
     bool insert = false;
     phys_addr_t obase = base;
     phys_addr_t end = base + memblock_cap_size(base, &size);
     int idx, nr_new;
     struct memblock_region *rgn;
 
     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;
         type->regions[0].flags = flags;
         memblock_set_region_node(&type->regions[0], nid);
         type->total_size = size;
         return 0;
     }
 
     /*
      * The worst case is when new range overlaps all existing regions,
      * then we'll need type->cnt + 1 empty regions in @type. So if
      * type->cnt * 2 + 1 is less than type->max, we know
      * that there is enough empty regions in @type, and we can insert
      * regions directly.
      */
     if (type->cnt * 2 + 1 < type->max)
         insert = true;
 
 repeat:
     /*
      * The following is executed twice.  Once with %false @insert and
      * then with %true.  The first counts the number of regions needed
      * to accommodate the new area.  The second actually inserts them.
      */
     base = obase;
     nr_new = 0;
 
     for_each_memblock_type(idx, type, rgn) {
         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) {
 #ifdef CONFIG_NUMA
             WARN_ON(nid != memblock_get_region_node(rgn));
 #endif
             WARN_ON(flags != rgn->flags);
             nr_new++;
             if (insert)
                 memblock_insert_region(type, idx++, base,
                                rbase - base, nid,
                                flags);
         }
         /* 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, idx, base, end - base,
                            nid, flags);
     }
 
     if (!nr_new)
         return 0;
 
     /*
      * 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;
     }
 }
 
 /**
  * memblock_add_node - add new memblock region within a NUMA node
  * @base: base address of the new region
  * @size: size of the new region
  * @nid: nid of the new region
  * @flags: flags of the new region
  *
  * Add new memblock region [@base, @base + @size) to the "memory"
  * type. See memblock_add_range() description for mode details
  *
  * Return:
  * 0 on success, -errno on failure.
  */
 int __init_memblock memblock_add_node(phys_addr_t base, phys_addr_t size,
                       int nid, enum memblock_flags flags)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] nid=%d flags=%x %pS\n", __func__,
              &base, &end, nid, flags, (void *)_RET_IP_);
 
     return memblock_add_range(&memblock.memory, base, size, nid, flags);
 }
 
 /**
  * memblock_add - add new memblock region
  * @base: base address of the new region
  * @size: size of the new region
  *
  * Add new memblock region [@base, @base + @size) to the "memory"
  * type. See memblock_add_range() description for mode details
  *
  * Return:
  * 0 on success, -errno on failure.
  */
 int __init_memblock memblock_add(phys_addr_t base, phys_addr_t size)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
              &base, &end, (void *)_RET_IP_);
 
     return memblock_add_range(&memblock.memory, base, size, MAX_NUMNODES, 0);
 }
 
 /**
  * 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.
  *
  * Return:
  * 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 idx;
     struct memblock_region *rgn;
 
     *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_each_memblock_type(idx, type, rgn) {
         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, idx, rbase, base - rbase,
                            memblock_get_region_node(rgn),
                            rgn->flags);
         } 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, idx--, rbase, end - rbase,
                            memblock_get_region_node(rgn),
                            rgn->flags);
         } else {
             /* @rgn is fully contained, record it */
             if (!*end_rgn)
                 *start_rgn = idx;
             *end_rgn = idx + 1;
         }
     }
 
     return 0;
 }
 
 static int __init_memblock memblock_remove_range(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)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
              &base, &end, (void *)_RET_IP_);
 
     return memblock_remove_range(&memblock.memory, base, size);
 }
 
 /**
  * memblock_free - free boot memory allocation
  * @ptr: starting address of the  boot memory allocation
  * @size: size of the boot memory block in bytes
  *
  * Free boot memory block previously allocated by memblock_alloc_xx() API.
  * The freeing memory will not be released to the buddy allocator.
  */
 void __init_memblock memblock_free(void *ptr, size_t size)
 {
     if (ptr)
         memblock_phys_free(__pa(ptr), size);
 }
 
 /**
  * memblock_phys_free - free boot memory block
  * @base: phys starting address of the  boot memory block
  * @size: size of the boot memory block in bytes
  *
  * Free boot memory block previously allocated by memblock_alloc_xx() API.
  * The freeing memory will not be released to the buddy allocator.
  */
 int __init_memblock memblock_phys_free(phys_addr_t base, phys_addr_t size)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
              &base, &end, (void *)_RET_IP_);
 
     kmemleak_free_part_phys(base, size);
     return memblock_remove_range(&memblock.reserved, base, size);
 }
 
 int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
              &base, &end, (void *)_RET_IP_);
 
     return memblock_add_range(&memblock.reserved, base, size, MAX_NUMNODES, 0);
 }
 
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
 int __init_memblock memblock_physmem_add(phys_addr_t base, phys_addr_t size)
 {
     phys_addr_t end = base + size - 1;
 
     memblock_dbg("%s: [%pa-%pa] %pS\n", __func__,
              &base, &end, (void *)_RET_IP_);
 
     return memblock_add_range(&physmem, base, size, MAX_NUMNODES, 0);
 }
 #endif
 
 /**
  * memblock_setclr_flag - set or clear flag for a memory region
  * @base: base address of the region
  * @size: size of the region
  * @set: set or clear the flag
  * @flag: the flag to update
  *
  * This function isolates region [@base, @base + @size), and sets/clears flag
  *
  * Return: 0 on success, -errno on failure.
  */
 static int __init_memblock memblock_setclr_flag(phys_addr_t base,
                 phys_addr_t size, int set, int flag)
 {
     struct memblock_type *type = &memblock.memory;
     int i, ret, start_rgn, end_rgn;
 
     ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
     if (ret)
         return ret;
 
     for (i = start_rgn; i < end_rgn; i++) {
         struct memblock_region *r = &type->regions[i];
 
         if (set)
             r->flags |= flag;
         else
             r->flags &= ~flag;
     }
 
     memblock_merge_regions(type);
     return 0;
 }
 
 /**
  * memblock_mark_hotplug - Mark hotpluggable memory with flag MEMBLOCK_HOTPLUG.
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_mark_hotplug(phys_addr_t base, phys_addr_t size)
 {
     return memblock_setclr_flag(base, size, 1, MEMBLOCK_HOTPLUG);
 }
 
 /**
  * memblock_clear_hotplug - Clear flag MEMBLOCK_HOTPLUG for a specified region.
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
 {
     return memblock_setclr_flag(base, size, 0, MEMBLOCK_HOTPLUG);
 }
 
 /**
  * memblock_mark_mirror - Mark mirrored memory with flag MEMBLOCK_MIRROR.
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
 {
     if (!mirrored_kernelcore)
         return 0;
 
     system_has_some_mirror = true;
 
     return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
 }
 
 /**
  * memblock_mark_nomap - Mark a memory region with flag MEMBLOCK_NOMAP.
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
  * The memory regions marked with %MEMBLOCK_NOMAP will not be added to the
  * direct mapping of the physical memory. These regions will still be
  * covered by the memory map. The struct page representing NOMAP memory
  * frames in the memory map will be PageReserved()
  *
  * Note: if the memory being marked %MEMBLOCK_NOMAP was allocated from
  * memblock, the caller must inform kmemleak to ignore that memory
  *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_mark_nomap(phys_addr_t base, phys_addr_t size)
 {
     return memblock_setclr_flag(base, size, 1, MEMBLOCK_NOMAP);
 }
 
 /**
  * memblock_clear_nomap - Clear flag MEMBLOCK_NOMAP for a specified region.
  * @base: the base phys addr of the region
  * @size: the size of the region
  *
  * Return: 0 on success, -errno on failure.
  */
 int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size)
 {
     return memblock_setclr_flag(base, size, 0, MEMBLOCK_NOMAP);
 }
 
 static bool should_skip_region(struct memblock_type *type,
                    struct memblock_region *m,
                    int nid, int flags)
 {
     int m_nid = memblock_get_region_node(m);
 
     /* we never skip regions when iterating memblock.reserved or physmem */
     if (type != memblock_memory)
         return false;
 
     /* only memory regions are associated with nodes, check it */
     if (nid != NUMA_NO_NODE && nid != m_nid)
         return true;
 
     /* skip hotpluggable memory regions if needed */
     if (movable_node_is_enabled() && memblock_is_hotpluggable(m) &&
         !(flags & MEMBLOCK_HOTPLUG))
         return true;
 
     /* if we want mirror memory skip non-mirror memory regions */
     if ((flags & MEMBLOCK_MIRROR) && !memblock_is_mirror(m))
         return true;
 
     /* skip nomap memory unless we were asked for it explicitly */
     if (!(flags & MEMBLOCK_NOMAP) && memblock_is_nomap(m))
         return true;
 
     /* skip driver-managed memory unless we were asked for it explicitly */
     if (!(flags & MEMBLOCK_DRIVER_MANAGED) && memblock_is_driver_managed(m))
         return true;
 
     return false;
 }
 
 /**
  * __next_mem_range - next function for for_each_free_mem_range() etc.
  * @idx: pointer to u64 loop variable
  * @nid: node selector, %NUMA_NO_NODE for all nodes
  * @flags: pick from blocks based on memory attributes
  * @type_a: pointer to memblock_type from where the range is taken
  * @type_b: pointer to memblock_type which excludes memory from being taken
  * @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 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 type_a and the upper 32bit indexes the
  * areas before each region in type_b.  For example, if type_b 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 __next_mem_range(u64 *idx, int nid, enum memblock_flags flags,
               struct memblock_type *type_a,
               struct memblock_type *type_b, phys_addr_t *out_start,
               phys_addr_t *out_end, int *out_nid)
 {
     int idx_a = *idx & 0xffffffff;
     int idx_b = *idx >> 32;
 
     if (WARN_ONCE(nid == MAX_NUMNODES,
     "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
         nid = NUMA_NO_NODE;
 
     for (; idx_a < type_a->cnt; idx_a++) {
         struct memblock_region *m = &type_a->regions[idx_a];
 
         phys_addr_t m_start = m->base;
         phys_addr_t m_end = m->base + m->size;
         int     m_nid = memblock_get_region_node(m);
 
         if (should_skip_region(type_a, m, nid, flags))
             continue;
 
         if (!type_b) {
             if (out_start)
                 *out_start = m_start;
             if (out_end)
                 *out_end = m_end;
             if (out_nid)
                 *out_nid = m_nid;
             idx_a++;
             *idx = (u32)idx_a | (u64)idx_b << 32;
             return;
         }
 
         /* scan areas before each reservation */
         for (; idx_b < type_b->cnt + 1; idx_b++) {
             struct memblock_region *r;
             phys_addr_t r_start;
             phys_addr_t r_end;
 
             r = &type_b->regions[idx_b];
             r_start = idx_b ? r[-1].base + r[-1].size : 0;
             r_end = idx_b < type_b->cnt ?
                 r->base : PHYS_ADDR_MAX;
 
             /*
              * if idx_b advanced past idx_a,
              * break out to advance idx_a
              */
             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 = m_nid;
                 /*
                  * The region which ends first is
                  * advanced for the next iteration.
                  */
                 if (m_end <= r_end)
                     idx_a++;
                 else
                     idx_b++;
                 *idx = (u32)idx_a | (u64)idx_b << 32;
                 return;
             }
         }
     }
 
     /* signal end of iteration */
     *idx = ULLONG_MAX;
 }
 
 /**
  * __next_mem_range_rev - generic next function for for_each_*_range_rev()
  *
  * @idx: pointer to u64 loop variable
  * @nid: node selector, %NUMA_NO_NODE for all nodes
  * @flags: pick from blocks based on memory attributes
  * @type_a: pointer to memblock_type from where the range is taken
  * @type_b: pointer to memblock_type which excludes memory from being taken
  * @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
  *
  * Finds the next range from type_a which is not marked as unsuitable
  * in type_b.
  *
  * Reverse of __next_mem_range().
  */
 void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
                       enum memblock_flags flags,
                       struct memblock_type *type_a,
                       struct memblock_type *type_b,
                       phys_addr_t *out_start,
                       phys_addr_t *out_end, int *out_nid)
 {
     int idx_a = *idx & 0xffffffff;
     int idx_b = *idx >> 32;
 
     if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
         nid = NUMA_NO_NODE;
 
     if (*idx == (u64)ULLONG_MAX) {
         idx_a = type_a->cnt - 1;
         if (type_b != NULL)
             idx_b = type_b->cnt;
         else
             idx_b = 0;
     }
 
     for (; idx_a >= 0; idx_a--) {
         struct memblock_region *m = &type_a->regions[idx_a];
 
         phys_addr_t m_start = m->base;
         phys_addr_t m_end = m->base + m->size;
         int m_nid = memblock_get_region_node(m);
 
         if (should_skip_region(type_a, m, nid, flags))
             continue;
 
         if (!type_b) {
             if (out_start)
                 *out_start = m_start;
             if (out_end)
                 *out_end = m_end;
             if (out_nid)
                 *out_nid = m_nid;
             idx_a--;
             *idx = (u32)idx_a | (u64)idx_b << 32;
             return;
         }
 
         /* scan areas before each reservation */
         for (; idx_b >= 0; idx_b--) {
             struct memblock_region *r;
             phys_addr_t r_start;
             phys_addr_t r_end;
 
             r = &type_b->regions[idx_b];
             r_start = idx_b ? r[-1].base + r[-1].size : 0;
             r_end = idx_b < type_b->cnt ?
                 r->base : PHYS_ADDR_MAX;
             /*
              * if idx_b advanced past idx_a,
              * break out to advance idx_a
              */
 
             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 = m_nid;
                 if (m_start >= r_start)
                     idx_a--;
                 else
                     idx_b--;
                 *idx = (u32)idx_a | (u64)idx_b << 32;
                 return;
             }
         }
     }
     /* signal end of iteration */
     *idx = ULLONG_MAX;
 }
 
 /*
  * Common iterator interface used to define for_each_mem_pfn_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;
     int r_nid;
 
     while (++*idx < type->cnt) {
         r = &type->regions[*idx];
         r_nid = memblock_get_region_node(r);
 
         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
  * @type: memblock type to set node ID for
  * @nid: node ID to set
  *
  * Set the nid of memblock @type regions in [@base, @base + @size) to @nid.
  * Regions which cross the area boundaries are split as necessary.
  *
  * Return:
  * 0 on success, -errno on failure.
  */
 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
                       struct memblock_type *type, int nid)
 {
 #ifdef CONFIG_NUMA
     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);
 #endif
     return 0;
 }
 
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 /**
  * __next_mem_pfn_range_in_zone - iterator for for_each_*_range_in_zone()
  *
  * @idx: pointer to u64 loop variable
  * @zone: zone in which all of the memory blocks reside
  * @out_spfn: ptr to ulong for start pfn of the range, can be %NULL
  * @out_epfn: ptr to ulong for end pfn of the range, can be %NULL
  *
  * This function is meant to be a zone/pfn specific wrapper for the
  * for_each_mem_range type iterators. Specifically they are used in the
  * deferred memory init routines and as such we were duplicating much of
  * this logic throughout the code. So instead of having it in multiple
  * locations it seemed like it would make more sense to centralize this to
  * one new iterator that does everything they need.
  */
 void __init_memblock
 __next_mem_pfn_range_in_zone(u64 *idx, struct zone *zone,
                  unsigned long *out_spfn, unsigned long *out_epfn)
 {
     int zone_nid = zone_to_nid(zone);
     phys_addr_t spa, epa;
 
     __next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
              &memblock.memory, &memblock.reserved,
              &spa, &epa, NULL);
 
     while (*idx != U64_MAX) {
         unsigned long epfn = PFN_DOWN(epa);
         unsigned long spfn = PFN_UP(spa);
 
         /*
          * Verify the end is at least past the start of the zone and
          * that we have at least one PFN to initialize.
          */
         if (zone->zone_start_pfn < epfn && spfn < epfn) {
             /* if we went too far just stop searching */
             if (zone_end_pfn(zone) <= spfn) {
                 *idx = U64_MAX;
                 break;
             }
 
             if (out_spfn)
                 *out_spfn = max(zone->zone_start_pfn, spfn);
             if (out_epfn)
                 *out_epfn = min(zone_end_pfn(zone), epfn);
 
             return;
         }
 
         __next_mem_range(idx, zone_nid, MEMBLOCK_NONE,
                  &memblock.memory, &memblock.reserved,
                  &spa, &epa, NULL);
     }
 
     /* signal end of iteration */
     if (out_spfn)
         *out_spfn = ULONG_MAX;
     if (out_epfn)
         *out_epfn = 0;
 }
 
 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
 
 /**
  * memblock_alloc_range_nid - allocate boot memory block
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @start: the lower bound of the memory region to allocate (phys address)
  * @end: the upper bound of the memory region to allocate (phys address)
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  * @exact_nid: control the allocation fall back to other nodes
  *
  * The allocation is performed from memory region limited by
  * memblock.current_limit if @end == %MEMBLOCK_ALLOC_ACCESSIBLE.
  *
  * If the specified node can not hold the requested memory and @exact_nid
  * is false, the allocation falls back to any node in the system.
  *
  * For systems with memory mirroring, the allocation is attempted first
  * from the regions with mirroring enabled and then retried from any
  * memory region.
  *
  * In addition, function using kmemleak_alloc_phys for allocated boot
  * memory block, it is never reported as leaks.
  *
  * Return:
  * Physical address of allocated memory block on success, %0 on failure.
  */
 phys_addr_t __init memblock_alloc_range_nid(phys_addr_t size,
                     phys_addr_t align, phys_addr_t start,
                     phys_addr_t end, int nid,
                     bool exact_nid)
 {
     enum memblock_flags flags = choose_memblock_flags();
     phys_addr_t found;
 
     if (WARN_ONCE(nid == MAX_NUMNODES, "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
         nid = NUMA_NO_NODE;
 
     if (!align) {
         /* Can't use WARNs this early in boot on powerpc */
         dump_stack();
         align = SMP_CACHE_BYTES;
     }
 
 again:
     found = memblock_find_in_range_node(size, align, start, end, nid,
                         flags);
     if (found && !memblock_reserve(found, size))
         goto done;
 
     if (nid != NUMA_NO_NODE && !exact_nid) {
         found = memblock_find_in_range_node(size, align, start,
                             end, NUMA_NO_NODE,
                             flags);
         if (found && !memblock_reserve(found, size))
             goto done;
     }
 
     if (flags & MEMBLOCK_MIRROR) {
         flags &= ~MEMBLOCK_MIRROR;
         pr_warn_ratelimited("Could not allocate %pap bytes of mirrored memory\n",
             &size);
         goto again;
     }
 
     return 0;
 
 done:
     /*
      * Skip kmemleak for those places like kasan_init() and
      * early_pgtable_alloc() due to high volume.
      */
     if (end != MEMBLOCK_ALLOC_NOLEAKTRACE)
         /*
          * Memblock allocated blocks are never reported as
          * leaks. This is because many of these blocks are
          * only referred via the physical address which is
          * not looked up by kmemleak.
          */
         kmemleak_alloc_phys(found, size, 0);
 
     return found;
 }
 
 /**
  * memblock_phys_alloc_range - allocate a memory block inside specified range
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @start: the lower bound of the memory region to allocate (physical address)
  * @end: the upper bound of the memory region to allocate (physical address)
  *
  * Allocate @size bytes in the between @start and @end.
  *
  * Return: physical address of the allocated memory block on success,
  * %0 on failure.
  */
 phys_addr_t __init memblock_phys_alloc_range(phys_addr_t size,
                          phys_addr_t align,
                          phys_addr_t start,
                          phys_addr_t end)
 {
     memblock_dbg("%s: %llu bytes align=0x%llx from=%pa max_addr=%pa %pS\n",
              __func__, (u64)size, (u64)align, &start, &end,
              (void *)_RET_IP_);
     return memblock_alloc_range_nid(size, align, start, end, NUMA_NO_NODE,
                     false);
 }
 
 /**
  * memblock_phys_alloc_try_nid - allocate a memory block from specified NUMA node
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  *
  * Allocates memory block from the specified NUMA node. If the node
  * has no available memory, attempts to allocated from any node in the
  * system.
  *
  * Return: physical address of the allocated memory block on success,
  * %0 on failure.
  */
 phys_addr_t __init memblock_phys_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid)
 {
     return memblock_alloc_range_nid(size, align, 0,
                     MEMBLOCK_ALLOC_ACCESSIBLE, nid, false);
 }
 
 /**
  * memblock_alloc_internal - allocate boot memory block
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @min_addr: the lower bound of the memory region to allocate (phys address)
  * @max_addr: the upper bound of the memory region to allocate (phys address)
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  * @exact_nid: control the allocation fall back to other nodes
  *
  * Allocates memory block using memblock_alloc_range_nid() and
  * converts the returned physical address to virtual.
  *
  * The @min_addr limit is dropped if it can not be satisfied and the allocation
  * will fall back to memory below @min_addr. Other constraints, such
  * as node and mirrored memory will be handled again in
  * memblock_alloc_range_nid().
  *
  * Return:
  * Virtual address of allocated memory block on success, NULL on failure.
  */
 static void * __init memblock_alloc_internal(
                 phys_addr_t size, phys_addr_t align,
                 phys_addr_t min_addr, phys_addr_t max_addr,
                 int nid, bool exact_nid)
 {
     phys_addr_t alloc;
 
     /*
      * Detect any accidental use of these APIs after slab is ready, as at
      * this moment memblock may be deinitialized already and its
      * internal data may be destroyed (after execution of memblock_free_all)
      */
     if (WARN_ON_ONCE(slab_is_available()))
         return kzalloc_node(size, GFP_NOWAIT, nid);
 
     if (max_addr > memblock.current_limit)
         max_addr = memblock.current_limit;
 
     alloc = memblock_alloc_range_nid(size, align, min_addr, max_addr, nid,
                     exact_nid);
 
     /* retry allocation without lower limit */
     if (!alloc && min_addr)
         alloc = memblock_alloc_range_nid(size, align, 0, max_addr, nid,
                         exact_nid);
 
     if (!alloc)
         return NULL;
 
     return phys_to_virt(alloc);
 }
 
 /**
  * memblock_alloc_exact_nid_raw - allocate boot memory block on the exact node
  * without zeroing memory
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @min_addr: the lower bound of the memory region from where the allocation
  *    is preferred (phys address)
  * @max_addr: the upper bound of the memory region from where the allocation
  *        is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
  *        allocate only from memory limited by memblock.current_limit value
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  *
  * Public function, provides additional debug information (including caller
  * info), if enabled. Does not zero allocated memory.
  *
  * Return:
  * Virtual address of allocated memory block on success, NULL on failure.
  */
 void * __init memblock_alloc_exact_nid_raw(
             phys_addr_t size, phys_addr_t align,
             phys_addr_t min_addr, phys_addr_t max_addr,
             int nid)
 {
     memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
              __func__, (u64)size, (u64)align, nid, &min_addr,
              &max_addr, (void *)_RET_IP_);
 
     return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
                        true);
 }
 
 /**
  * memblock_alloc_try_nid_raw - allocate boot memory block without zeroing
  * memory and without panicking
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @min_addr: the lower bound of the memory region from where the allocation
  *    is preferred (phys address)
  * @max_addr: the upper bound of the memory region from where the allocation
  *        is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
  *        allocate only from memory limited by memblock.current_limit value
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  *
  * Public function, provides additional debug information (including caller
  * info), if enabled. Does not zero allocated memory, does not panic if request
  * cannot be satisfied.
  *
  * Return:
  * Virtual address of allocated memory block on success, NULL on failure.
  */
 void * __init memblock_alloc_try_nid_raw(
             phys_addr_t size, phys_addr_t align,
             phys_addr_t min_addr, phys_addr_t max_addr,
             int nid)
 {
     memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
              __func__, (u64)size, (u64)align, nid, &min_addr,
              &max_addr, (void *)_RET_IP_);
 
     return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
                        false);
 }
 
 /**
  * memblock_alloc_try_nid - allocate boot memory block
  * @size: size of memory block to be allocated in bytes
  * @align: alignment of the region and block's size
  * @min_addr: the lower bound of the memory region from where the allocation
  *    is preferred (phys address)
  * @max_addr: the upper bound of the memory region from where the allocation
  *        is preferred (phys address), or %MEMBLOCK_ALLOC_ACCESSIBLE to
  *        allocate only from memory limited by memblock.current_limit value
  * @nid: nid of the free area to find, %NUMA_NO_NODE for any node
  *
  * Public function, provides additional debug information (including caller
  * info), if enabled. This function zeroes the allocated memory.
  *
  * Return:
  * Virtual address of allocated memory block on success, NULL on failure.
  */
 void * __init memblock_alloc_try_nid(
             phys_addr_t size, phys_addr_t align,
             phys_addr_t min_addr, phys_addr_t max_addr,
             int nid)
 {
     void *ptr;
 
     memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
              __func__, (u64)size, (u64)align, nid, &min_addr,
              &max_addr, (void *)_RET_IP_);
     ptr = memblock_alloc_internal(size, align,
                        min_addr, max_addr, nid, false);
     if (ptr)
         memset(ptr, 0, size);
 
     return ptr;
 }
 
 /**
  * memblock_free_late - free pages directly to buddy allocator
  * @base: phys starting address of the  boot memory block
  * @size: size of the boot memory block in bytes
  *
  * This is only useful when the memblock allocator has already been torn
  * down, but we are still initializing the system.  Pages are released directly
  * to the buddy allocator.
  */
 void __init memblock_free_late(phys_addr_t base, phys_addr_t size)
 {
     phys_addr_t cursor, end;
 
     end = base + size - 1;
     memblock_dbg("%s: [%pa-%pa] %pS\n",
              __func__, &base, &end, (void *)_RET_IP_);
     kmemleak_free_part_phys(base, size);
     cursor = PFN_UP(base);
     end = PFN_DOWN(base + size);
 
     for (; cursor < end; cursor++) {
         memblock_free_pages(pfn_to_page(cursor), cursor, 0);
         totalram_pages_inc();
     }
 }
 
 /*
  * Remaining API functions
  */
 
 phys_addr_t __init_memblock memblock_phys_mem_size(void)
 {
     return memblock.memory.total_size;
 }
 
 phys_addr_t __init_memblock memblock_reserved_size(void)
 {
     return memblock.reserved.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);
 }
 
 static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit)
 {
     phys_addr_t max_addr = PHYS_ADDR_MAX;
     struct memblock_region *r;
 
     /*
      * translate the memory @limit size into the max address within one of
      * the memory memblock regions, if the @limit exceeds the total size
      * of those regions, max_addr will keep original value PHYS_ADDR_MAX
      */
     for_each_mem_region(r) {
         if (limit <= r->size) {
             max_addr = r->base + limit;
             break;
         }
         limit -= r->size;
     }
 
     return max_addr;
 }
 
 void __init memblock_enforce_memory_limit(phys_addr_t limit)
 {
     phys_addr_t max_addr;
 
     if (!limit)
         return;
 
     max_addr = __find_max_addr(limit);
 
     /* @limit exceeds the total size of the memory, do nothing */
     if (max_addr == PHYS_ADDR_MAX)
         return;
 
     /* truncate both memory and reserved regions */
     memblock_remove_range(&memblock.memory, max_addr,
                   PHYS_ADDR_MAX);
     memblock_remove_range(&memblock.reserved, max_addr,
                   PHYS_ADDR_MAX);
 }
 
 void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
 {
     int start_rgn, end_rgn;
     int i, ret;
 
     if (!size)
         return;
 
     if (!memblock_memory->total_size) {
         pr_warn("%s: No memory registered yet\n", __func__);
         return;
     }
 
     ret = memblock_isolate_range(&memblock.memory, base, size,
                         &start_rgn, &end_rgn);
     if (ret)
         return;
 
     /* remove all the MAP regions */
     for (i = memblock.memory.cnt - 1; i >= end_rgn; i--)
         if (!memblock_is_nomap(&memblock.memory.regions[i]))
             memblock_remove_region(&memblock.memory, i);
 
     for (i = start_rgn - 1; i >= 0; i--)
         if (!memblock_is_nomap(&memblock.memory.regions[i]))
             memblock_remove_region(&memblock.memory, i);
 
     /* truncate the reserved regions */
     memblock_remove_range(&memblock.reserved, 0, base);
     memblock_remove_range(&memblock.reserved,
             base + size, PHYS_ADDR_MAX);
 }
 
 void __init memblock_mem_limit_remove_map(phys_addr_t limit)
 {
     phys_addr_t max_addr;
 
     if (!limit)
         return;
 
     max_addr = __find_max_addr(limit);
 
     /* @limit exceeds the total size of the memory, do nothing */
     if (max_addr == PHYS_ADDR_MAX)
         return;
 
     memblock_cap_memory_range(0, max_addr);
 }
 
 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;
 }
 
 bool __init_memblock memblock_is_reserved(phys_addr_t addr)
 {
     return memblock_search(&memblock.reserved, addr) != -1;
 }
 
 bool __init_memblock memblock_is_memory(phys_addr_t addr)
 {
     return memblock_search(&memblock.memory, addr) != -1;
 }
 
 bool __init_memblock memblock_is_map_memory(phys_addr_t addr)
 {
     int i = memblock_search(&memblock.memory, addr);
 
     if (i == -1)
         return false;
     return !memblock_is_nomap(&memblock.memory.regions[i]);
 }
 
 int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
              unsigned long *start_pfn, unsigned long *end_pfn)
 {
     struct memblock_type *type = &memblock.memory;
     int mid = memblock_search(type, PFN_PHYS(pfn));
 
     if (mid == -1)
         return -1;
 
     *start_pfn = PFN_DOWN(type->regions[mid].base);
     *end_pfn = PFN_DOWN(type->regions[mid].base + type->regions[mid].size);
 
     return memblock_get_region_node(&type->regions[mid]);
 }
 
 /**
  * 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.
  *
  * Return:
  * 0 if false, non-zero if true
  */
 bool __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 false;
     return (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.
  *
  * Return:
  * True if they intersect, false if not.
  */
 bool __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size)
 {
     return memblock_overlaps_region(&memblock.reserved, base, size);
 }
 
 void __init_memblock memblock_trim_memory(phys_addr_t align)
 {
     phys_addr_t start, end, orig_start, orig_end;
     struct memblock_region *r;
 
     for_each_mem_region(r) {
         orig_start = r->base;
         orig_end = r->base + r->size;
         start = round_up(orig_start, align);
         end = round_down(orig_end, align);
 
         if (start == orig_start && end == orig_end)
             continue;
 
         if (start < end) {
             r->base = start;
             r->size = end - start;
         } else {
             memblock_remove_region(&memblock.memory,
                            r - memblock.memory.regions);
             r--;
         }
     }
 }
 
 void __init_memblock memblock_set_current_limit(phys_addr_t limit)
 {
     memblock.current_limit = limit;
 }
 
 phys_addr_t __init_memblock memblock_get_current_limit(void)
 {
     return memblock.current_limit;
 }
 
 static void __init_memblock memblock_dump(struct memblock_type *type)
 {
     phys_addr_t base, end, size;
     enum memblock_flags flags;
     int idx;
     struct memblock_region *rgn;
 
     pr_info(" %s.cnt  = 0x%lx\n", type->name, type->cnt);
 
     for_each_memblock_type(idx, type, rgn) {
         char nid_buf[32] = "";
 
         base = rgn->base;
         size = rgn->size;
         end = base + size - 1;
         flags = rgn->flags;
 #ifdef CONFIG_NUMA
         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[%pa-%pa], %pa bytes%s flags: %#x\n",
             type->name, idx, &base, &end, &size, nid_buf, flags);
     }
 }
 
 static void __init_memblock __memblock_dump_all(void)
 {
     pr_info("MEMBLOCK configuration:\n");
     pr_info(" memory size = %pa reserved size = %pa\n",
         &memblock.memory.total_size,
         &memblock.reserved.total_size);
 
     memblock_dump(&memblock.memory);
     memblock_dump(&memblock.reserved);
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
     memblock_dump(&physmem);
 #endif
 }
 
 void __init_memblock memblock_dump_all(void)
 {
     if (memblock_debug)
         __memblock_dump_all();
 }
 
 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);
 
 static void __init free_memmap(unsigned long start_pfn, unsigned long end_pfn)
 {
     struct page *start_pg, *end_pg;
     phys_addr_t pg, pgend;
 
     /*
      * Convert start_pfn/end_pfn to a struct page pointer.
      */
     start_pg = pfn_to_page(start_pfn - 1) + 1;
     end_pg = pfn_to_page(end_pfn - 1) + 1;
 
     /*
      * Convert to physical addresses, and round start upwards and end
      * downwards.
      */
     pg = PAGE_ALIGN(__pa(start_pg));
     pgend = __pa(end_pg) & PAGE_MASK;
 
     /*
      * If there are free pages between these, free the section of the
      * memmap array.
      */
     if (pg < pgend)
         memblock_phys_free(pg, pgend - pg);
 }
 
 /*
  * The mem_map array can get very big.  Free the unused area of the memory map.
  */
 static void __init free_unused_memmap(void)
 {
     unsigned long start, end, prev_end = 0;
     int i;
 
     if (!IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) ||
         IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP))
         return;
 
     /*
      * This relies on each bank being in address order.
      * The banks are sorted previously in bootmem_init().
      */
     for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
 #ifdef CONFIG_SPARSEMEM
         /*
          * Take care not to free memmap entries that don't exist
          * due to SPARSEMEM sections which aren't present.
          */
         start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
 #endif
         /*
          * Align down here since many operations in VM subsystem
          * presume that there are no holes in the memory map inside
          * a pageblock
          */
         start = round_down(start, pageblock_nr_pages);
 
         /*
          * If we had a previous bank, and there is a space
          * between the current bank and the previous, free it.
          */
         if (prev_end && prev_end < start)
             free_memmap(prev_end, start);
 
         /*
          * Align up here since many operations in VM subsystem
          * presume that there are no holes in the memory map inside
          * a pageblock
          */
         prev_end = ALIGN(end, pageblock_nr_pages);
     }
 
 #ifdef CONFIG_SPARSEMEM
     if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) {
         prev_end = ALIGN(end, pageblock_nr_pages);
         free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
     }
 #endif
 }
 
 static void __init __free_pages_memory(unsigned long start, unsigned long end)
 {
     int order;
 
     while (start < end) {
         order = min(MAX_ORDER - 1UL, __ffs(start));
 
         while (start + (1UL << order) > end)
             order--;
 
         memblock_free_pages(pfn_to_page(start), start, order);
 
         start += (1UL << order);
     }
 }
 
 static unsigned long __init __free_memory_core(phys_addr_t start,
                  phys_addr_t end)
 {
     unsigned long start_pfn = PFN_UP(start);
     unsigned long end_pfn = min_t(unsigned long,
                       PFN_DOWN(end), max_low_pfn);
 
     if (start_pfn >= end_pfn)
         return 0;
 
     __free_pages_memory(start_pfn, end_pfn);
 
     return end_pfn - start_pfn;
 }
 
 static void __init memmap_init_reserved_pages(void)
 {
     struct memblock_region *region;
     phys_addr_t start, end;
     u64 i;
 
     /* initialize struct pages for the reserved regions */
     for_each_reserved_mem_range(i, &start, &end)
         reserve_bootmem_region(start, end);
 
     /* and also treat struct pages for the NOMAP regions as PageReserved */
     for_each_mem_region(region) {
         if (memblock_is_nomap(region)) {
             start = region->base;
             end = start + region->size;
             reserve_bootmem_region(start, end);
         }
     }
 }
 
 static unsigned long __init free_low_memory_core_early(void)
 {
     unsigned long count = 0;
     phys_addr_t start, end;
     u64 i;
 
     memblock_clear_hotplug(0, -1);
 
     memmap_init_reserved_pages();
 
     /*
      * We need to use NUMA_NO_NODE instead of NODE_DATA(0)->node_id
      *  because in some case like Node0 doesn't have RAM installed
      *  low ram will be on Node1
      */
     for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end,
                 NULL)
         count += __free_memory_core(start, end);
 
     return count;
 }
 
 static int reset_managed_pages_done __initdata;
 
 void reset_node_managed_pages(pg_data_t *pgdat)
 {
     struct zone *z;
 
     for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++)
         atomic_long_set(&z->managed_pages, 0);
 }
 
 void __init reset_all_zones_managed_pages(void)
 {
     struct pglist_data *pgdat;
 
     if (reset_managed_pages_done)
         return;
 
     for_each_online_pgdat(pgdat)
         reset_node_managed_pages(pgdat);
 
     reset_managed_pages_done = 1;
 }
 
 /**
  * memblock_free_all - release free pages to the buddy allocator
  */
 void __init memblock_free_all(void)
 {
     unsigned long pages;
 
     free_unused_memmap();
     reset_all_zones_managed_pages();
 
     pages = free_low_memory_core_early();
     totalram_pages_add(pages);
 }
 
 #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)
 
 static int memblock_debug_show(struct seq_file *m, void *private)
 {
     struct memblock_type *type = m->private;
     struct memblock_region *reg;
     int i;
     phys_addr_t end;
 
     for (i = 0; i < type->cnt; i++) {
         reg = &type->regions[i];
         end = reg->base + reg->size - 1;
 
         seq_printf(m, "%4d: ", i);
         seq_printf(m, "%pa..%pa\n", &reg->base, &end);
     }
     return 0;
 }
 DEFINE_SHOW_ATTRIBUTE(memblock_debug);
 
 static int __init memblock_init_debugfs(void)
 {
     struct dentry *root = debugfs_create_dir("memblock", NULL);
 
     debugfs_create_file("memory", 0444, root,
                 &memblock.memory, &memblock_debug_fops);
     debugfs_create_file("reserved", 0444, root,
                 &memblock.reserved, &memblock_debug_fops);
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
     debugfs_create_file("physmem", 0444, root, &physmem,
                 &memblock_debug_fops);
 #endif
 
     return 0;
 }
 __initcall(memblock_init_debugfs);
 
 #endif /* CONFIG_DEBUG_FS */

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