Merge tag 'char-misc-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh...

[linux-2.6-microblaze.git] / mm / memblock.c

// 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

/**
 * 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_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_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_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;
        }
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 sets the min_count to 0 using kmemleak_alloc_phys for
 * allocated boot memory block, so that 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)
                /*
                 * The min_count is set to 0 so that 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, 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 */