[linux-2.6-block.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 <linux/mutex.h>

#ifdef CONFIG_KEXEC_HANDOVER
#include <linux/libfdt.h>
#include <linux/kexec_handover.h>
#endif /* CONFIG_KEXEC_HANDOVER */

#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;

#ifdef CONFIG_MEMBLOCK_KHO_SCRATCH
/* When set to true, only allocate from MEMBLOCK_KHO_SCRATCH ranges */
static bool kho_scratch_only;
#else
#define kho_scratch_only false
#endif

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.max             = INIT_MEMBLOCK_MEMORY_REGIONS,
        .memory.name            = "memory",

        .reserved.regions       = memblock_reserved_init_regions,
        .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,
        .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;
static int memblock_can_resize __initdata_memblock;
static int memblock_memory_in_slab __initdata_memblock;
static int memblock_reserved_in_slab __initdata_memblock;

bool __init_memblock memblock_has_mirror(void)
{
        return system_has_some_mirror;
}

static enum memblock_flags __init_memblock choose_memblock_flags(void)
{
        /* skip non-scratch memory for kho early boot allocations */
        if (kho_scratch_only)
                return MEMBLOCK_KHO_SCRATCH;

        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
 */
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))
                        return true;
        return false;
}

/**
 * __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->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)
                panic("memblock: cannot resize %s array\n", type->name);

        /* 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);

                if (addr) {
                        /* The memory may not have been accepted, yet. */
                        accept_memory(addr, new_alloc_size);

                        new_array = __va(addr);
                } else {
                        new_array = 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_kern(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
 * @start_rgn: start scanning from (@start_rgn - 1)
 * @end_rgn: end scanning at (@end_rgn - 1)
 * Scan @type and merge neighboring compatible regions in [@start_rgn - 1, @end_rgn)
 */
static void __init_memblock memblock_merge_regions(struct memblock_type *type,
                                                   unsigned long start_rgn,
                                                   unsigned long end_rgn)
{
        int i = 0;
        if (start_rgn)
                i = start_rgn - 1;
        end_rgn = min(end_rgn, type->cnt - 1);
        while (i < end_rgn) {
                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--;
                end_rgn--;
        }
}

/**
 * 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, start_rgn = -1, end_rgn;
        struct memblock_region *rgn;

        if (!size)
                return 0;

        /* special case for empty array */
        if (type->regions[0].size == 0) {
                WARN_ON(type->cnt != 0 || 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;
                type->cnt = 1;
                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 or equal to 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 != MEMBLOCK_NONE && flags != rgn->flags);
                        nr_new++;
                        if (insert) {
                                if (start_rgn == -1)
                                        start_rgn = idx;
                                end_rgn = idx + 1;
                                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) {
                        if (start_rgn == -1)
                                start_rgn = idx;
                        end_rgn = idx + 1;
                        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, start_rgn, end_rgn);
                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_validate_numa_coverage - check if amount of memory with
 * no node ID assigned is less than a threshold
 * @threshold_bytes: maximal memory size that can have unassigned node
 * ID (in bytes).
 *
 * A buggy firmware may report memory that does not belong to any node.
 * Check if amount of such memory is below @threshold_bytes.
 *
 * Return: true on success, false on failure.
 */
bool __init_memblock memblock_validate_numa_coverage(unsigned long threshold_bytes)
{
        unsigned long nr_pages = 0;
        unsigned long start_pfn, end_pfn, mem_size_mb;
        int nid, i;

        /* calculate lose page */
        for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
                if (!numa_valid_node(nid))
                        nr_pages += end_pfn - start_pfn;
        }

        if ((nr_pages << PAGE_SHIFT) > threshold_bytes) {
                mem_size_mb = memblock_phys_mem_size() >> 20;
                pr_err("NUMA: no nodes coverage for %luMB of %luMB RAM\n",
                       (nr_pages << PAGE_SHIFT) >> 20, mem_size_mb);
                return false;
        }

        return true;
}


/**
 * 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 the index of the
 * first region after the range is returned 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_phys_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,
                                       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.reserved, base, size, nid, flags);
}

#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

#ifdef CONFIG_MEMBLOCK_KHO_SCRATCH
__init void memblock_set_kho_scratch_only(void)
{
        kho_scratch_only = true;
}

__init void memblock_clear_kho_scratch_only(void)
{
        kho_scratch_only = false;
}

__init void memmap_init_kho_scratch_pages(void)
{
        phys_addr_t start, end;
        unsigned long pfn;
        int nid;
        u64 i;

        if (!IS_ENABLED(CONFIG_DEFERRED_STRUCT_PAGE_INIT))
                return;

        /*
         * Initialize struct pages for free scratch memory.
         * The struct pages for reserved scratch memory will be set up in
         * reserve_bootmem_region()
         */
        __for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE,
                             MEMBLOCK_KHO_SCRATCH, &start, &end, &nid) {
                for (pfn = PFN_UP(start); pfn < PFN_DOWN(end); pfn++)
                        init_deferred_page(pfn, nid);
        }
}
#endif

/**
 * memblock_setclr_flag - set or clear flag for a memory region
 * @type: memblock type to set/clear flag for
 * @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(struct memblock_type *type,
                                phys_addr_t base, phys_addr_t size, int set, int flag)
{
        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, start_rgn, end_rgn);
        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(&memblock.memory, 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(&memblock.memory, 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(&memblock.memory, 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(&memblock.memory, 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(&memblock.memory, base, size, 0, MEMBLOCK_NOMAP);
}

/**
 * memblock_reserved_mark_noinit - Mark a reserved memory region with flag
 * MEMBLOCK_RSRV_NOINIT which results in the struct pages not being initialized
 * for this region.
 * @base: the base phys addr of the region
 * @size: the size of the region
 *
 * struct pages will not be initialized for reserved memory regions marked with
 * %MEMBLOCK_RSRV_NOINIT.
 *
 * Return: 0 on success, -errno on failure.
 */
int __init_memblock memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size)
{
        return memblock_setclr_flag(&memblock.reserved, base, size, 1,
                                    MEMBLOCK_RSRV_NOINIT);
}

/**
 * memblock_mark_kho_scratch - Mark a memory region as MEMBLOCK_KHO_SCRATCH.
 * @base: the base phys addr of the region
 * @size: the size of the region
 *
 * Only memory regions marked with %MEMBLOCK_KHO_SCRATCH will be considered
 * for allocations during early boot with kexec handover.
 *
 * Return: 0 on success, -errno on failure.
 */
__init int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size)
{
        return memblock_setclr_flag(&memblock.memory, base, size, 1,
                                    MEMBLOCK_KHO_SCRATCH);
}

/**
 * memblock_clear_kho_scratch - Clear MEMBLOCK_KHO_SCRATCH flag 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.
 */
__init int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size)
{
        return memblock_setclr_flag(&memblock.memory, base, size, 0,
                                    MEMBLOCK_KHO_SCRATCH);
}

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 (numa_valid_node(nid) && 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;

        /*
         * In early alloc during kexec handover, we can only consider
         * MEMBLOCK_KHO_SCRATCH regions for the allocations
         */
        if ((flags & MEMBLOCK_KHO_SCRATCH) && !memblock_is_kho_scratch(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;

        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 (*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 (!numa_valid_node(nid) || 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, start_rgn, end_rgn);
#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;

        /*
         * 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())) {
                void *vaddr = kzalloc_node(size, GFP_NOWAIT, nid);

                return vaddr ? virt_to_phys(vaddr) : 0;
        }

        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, nid, MEMBLOCK_RSRV_KERN))
                goto done;

        if (numa_valid_node(nid) && !exact_nid) {
                found = memblock_find_in_range_node(size, align, start,
                                                    end, NUMA_NO_NODE,
                                                    flags);
                if (found && !memblock_reserve_kern(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);

        /*
         * Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP,
         * require memory to be accepted before it can be used by the
         * guest.
         *
         * Accept the memory of the allocated buffer.
         */
        accept_memory(found, size);

        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;


        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_alloc_or_panic - Try to allocate memory and panic on failure
 * @size: size of memory block to be allocated in bytes
 * @align: alignment of the region and block's size
 * @func: caller func name
 *
 * This function attempts to allocate memory using memblock_alloc,
 * and in case of failure, it calls panic with the formatted message.
 * This function should not be used directly, please use the macro memblock_alloc_or_panic.
 */
void *__init __memblock_alloc_or_panic(phys_addr_t size, phys_addr_t align,
                                       const char *func)
{
        void *addr = memblock_alloc(size, align);

        if (unlikely(!addr))
                panic("%s: Failed to allocate %pap bytes\n", func, &size);
        return addr;
}

/**
 * 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;
}

phys_addr_t __init_memblock memblock_reserved_kern_size(phys_addr_t limit, int nid)
{
        struct memblock_region *r;
        phys_addr_t total = 0;

        for_each_reserved_mem_region(r) {
                phys_addr_t size = r->size;

                if (r->base > limit)
                        break;

                if (r->base + r->size > limit)
                        size = limit - r->base;

                if (nid == memblock_get_region_node(r) || !numa_valid_node(nid))
                        if (r->flags & MEMBLOCK_RSRV_KERN)
                                total += size;
        }

        return total;
}

/**
 * memblock_estimated_nr_free_pages - return estimated number of free pages
 * from memblock point of view
 *
 * During bootup, subsystems might need a rough estimate of the number of free
 * pages in the whole system, before precise numbers are available from the
 * buddy. Especially with CONFIG_DEFERRED_STRUCT_PAGE_INIT, the numbers
 * obtained from the buddy might be very imprecise during bootup.
 *
 * Return:
 * An estimated number of free pages from memblock point of view.
 */
unsigned long __init memblock_estimated_nr_free_pages(void)
{
        return PHYS_PFN(memblock_phys_mem_size() - memblock_reserved_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 NUMA_NO_NODE;

        *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 (numa_valid_node(memblock_get_region_node(rgn)))
                        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 = PAGE_ALIGN_DOWN(__pa(end_pg));

        /*
         * 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 = pageblock_start_pfn(start);

                /*
                 * 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 = pageblock_align(end);
        }

#ifdef CONFIG_SPARSEMEM
        if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION)) {
                prev_end = pageblock_align(end);
                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) {
                /*
                 * Free the pages in the largest chunks alignment allows.
                 *
                 * __ffs() behaviour is undefined for 0. start == 0 is
                 * MAX_PAGE_ORDER-aligned, set order to MAX_PAGE_ORDER for
                 * the case.
                 */
                if (start)
                        order = min_t(int, MAX_PAGE_ORDER, __ffs(start));
                else
                        order = MAX_PAGE_ORDER;

                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 = PFN_DOWN(end);

        if (!IS_ENABLED(CONFIG_HIGHMEM) && end_pfn > max_low_pfn)
                end_pfn = 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;
        int nid;
        unsigned long max_reserved;

        /*
         * set nid on all reserved pages and also treat struct
         * pages for the NOMAP regions as PageReserved
         */
repeat:
        max_reserved = memblock.reserved.max;
        for_each_mem_region(region) {
                nid = memblock_get_region_node(region);
                start = region->base;
                end = start + region->size;

                if (memblock_is_nomap(region))
                        reserve_bootmem_region(start, end, nid);

                memblock_set_node(start, region->size, &memblock.reserved, nid);
        }
        /*
         * 'max' is changed means memblock.reserved has been doubled its
         * array, which may result a new reserved region before current
         * 'start'. Now we should repeat the procedure to set its node id.
         */
        if (max_reserved != memblock.reserved.max)
                goto repeat;

        /*
         * initialize struct pages for reserved regions that don't have
         * the MEMBLOCK_RSRV_NOINIT flag set
         */
        for_each_reserved_mem_region(region) {
                if (!memblock_is_reserved_noinit(region)) {
                        nid = memblock_get_region_node(region);
                        start = region->base;
                        end = start + region->size;

                        if (!numa_valid_node(nid))
                                nid = early_pfn_to_nid(PFN_DOWN(start));

                        reserve_bootmem_region(start, end, nid);
                }
        }
}

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;

static void __init 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();

        memblock_clear_kho_scratch_only();
        pages = free_low_memory_core_early();
        totalram_pages_add(pages);
}

/* Keep a table to reserve named memory */
#define RESERVE_MEM_MAX_ENTRIES         8
#define RESERVE_MEM_NAME_SIZE           16
struct reserve_mem_table {
        char                    name[RESERVE_MEM_NAME_SIZE];
        phys_addr_t             start;
        phys_addr_t             size;
};
static struct reserve_mem_table reserved_mem_table[RESERVE_MEM_MAX_ENTRIES];
static int reserved_mem_count;
static DEFINE_MUTEX(reserve_mem_lock);

/* Add wildcard region with a lookup name */
static void __init reserved_mem_add(phys_addr_t start, phys_addr_t size,
                                   const char *name)
{
        struct reserve_mem_table *map;

        map = &reserved_mem_table[reserved_mem_count++];
        map->start = start;
        map->size = size;
        strscpy(map->name, name);
}

static struct reserve_mem_table *reserve_mem_find_by_name_nolock(const char *name)
{
        struct reserve_mem_table *map;
        int i;

        for (i = 0; i < reserved_mem_count; i++) {
                map = &reserved_mem_table[i];
                if (!map->size)
                        continue;
                if (strcmp(name, map->name) == 0)
                        return map;
        }
        return NULL;
}

/**
 * reserve_mem_find_by_name - Find reserved memory region with a given name
 * @name: The name that is attached to a reserved memory region
 * @start: If found, holds the start address
 * @size: If found, holds the size of the address.
 *
 * @start and @size are only updated if @name is found.
 *
 * Returns: 1 if found or 0 if not found.
 */
int reserve_mem_find_by_name(const char *name, phys_addr_t *start, phys_addr_t *size)
{
        struct reserve_mem_table *map;

        guard(mutex)(&reserve_mem_lock);
        map = reserve_mem_find_by_name_nolock(name);
        if (!map)
                return 0;

        *start = map->start;
        *size = map->size;
        return 1;
}
EXPORT_SYMBOL_GPL(reserve_mem_find_by_name);

/**
 * reserve_mem_release_by_name - Release reserved memory region with a given name
 * @name: The name that is attatched to a reserved memory region
 *
 * Forcibly release the pages in the reserved memory region so that those memory
 * can be used as free memory. After released the reserved region size becomes 0.
 *
 * Returns: 1 if released or 0 if not found.
 */
int reserve_mem_release_by_name(const char *name)
{
        char buf[RESERVE_MEM_NAME_SIZE + 12];
        struct reserve_mem_table *map;
        void *start, *end;

        guard(mutex)(&reserve_mem_lock);
        map = reserve_mem_find_by_name_nolock(name);
        if (!map)
                return 0;

        start = phys_to_virt(map->start);
        end = start + map->size - 1;
        snprintf(buf, sizeof(buf), "reserve_mem:%s", name);
        free_reserved_area(start, end, 0, buf);
        map->size = 0;

        return 1;
}

#ifdef CONFIG_KEXEC_HANDOVER
#define MEMBLOCK_KHO_FDT "memblock"
#define MEMBLOCK_KHO_NODE_COMPATIBLE "memblock-v1"
#define RESERVE_MEM_KHO_NODE_COMPATIBLE "reserve-mem-v1"
static struct page *kho_fdt;

static int reserve_mem_kho_finalize(struct kho_serialization *ser)
{
        int err = 0, i;

        for (i = 0; i < reserved_mem_count; i++) {
                struct reserve_mem_table *map = &reserved_mem_table[i];

                err |= kho_preserve_phys(map->start, map->size);
        }

        err |= kho_preserve_folio(page_folio(kho_fdt));
        err |= kho_add_subtree(ser, MEMBLOCK_KHO_FDT, page_to_virt(kho_fdt));

        return notifier_from_errno(err);
}

static int reserve_mem_kho_notifier(struct notifier_block *self,
                                    unsigned long cmd, void *v)
{
        switch (cmd) {
        case KEXEC_KHO_FINALIZE:
                return reserve_mem_kho_finalize((struct kho_serialization *)v);
        case KEXEC_KHO_ABORT:
                return NOTIFY_DONE;
        default:
                return NOTIFY_BAD;
        }
}

static struct notifier_block reserve_mem_kho_nb = {
        .notifier_call = reserve_mem_kho_notifier,
};

static int __init prepare_kho_fdt(void)
{
        int err = 0, i;
        void *fdt;

        kho_fdt = alloc_page(GFP_KERNEL);
        if (!kho_fdt)
                return -ENOMEM;

        fdt = page_to_virt(kho_fdt);

        err |= fdt_create(fdt, PAGE_SIZE);
        err |= fdt_finish_reservemap(fdt);

        err |= fdt_begin_node(fdt, "");
        err |= fdt_property_string(fdt, "compatible", MEMBLOCK_KHO_NODE_COMPATIBLE);
        for (i = 0; i < reserved_mem_count; i++) {
                struct reserve_mem_table *map = &reserved_mem_table[i];

                err |= fdt_begin_node(fdt, map->name);
                err |= fdt_property_string(fdt, "compatible", RESERVE_MEM_KHO_NODE_COMPATIBLE);
                err |= fdt_property(fdt, "start", &map->start, sizeof(map->start));
                err |= fdt_property(fdt, "size", &map->size, sizeof(map->size));
                err |= fdt_end_node(fdt);
        }
        err |= fdt_end_node(fdt);

        err |= fdt_finish(fdt);

        if (err) {
                pr_err("failed to prepare memblock FDT for KHO: %d\n", err);
                put_page(kho_fdt);
                kho_fdt = NULL;
        }

        return err;
}

static int __init reserve_mem_init(void)
{
        int err;

        if (!kho_is_enabled() || !reserved_mem_count)
                return 0;

        err = prepare_kho_fdt();
        if (err)
                return err;

        err = register_kho_notifier(&reserve_mem_kho_nb);
        if (err) {
                put_page(kho_fdt);
                kho_fdt = NULL;
        }

        return err;
}
late_initcall(reserve_mem_init);

static void *__init reserve_mem_kho_retrieve_fdt(void)
{
        phys_addr_t fdt_phys;
        static void *fdt;
        int err;

        if (fdt)
                return fdt;

        err = kho_retrieve_subtree(MEMBLOCK_KHO_FDT, &fdt_phys);
        if (err) {
                if (err != -ENOENT)
                        pr_warn("failed to retrieve FDT '%s' from KHO: %d\n",
                                MEMBLOCK_KHO_FDT, err);
                return NULL;
        }

        fdt = phys_to_virt(fdt_phys);

        err = fdt_node_check_compatible(fdt, 0, MEMBLOCK_KHO_NODE_COMPATIBLE);
        if (err) {
                pr_warn("FDT '%s' is incompatible with '%s': %d\n",
                        MEMBLOCK_KHO_FDT, MEMBLOCK_KHO_NODE_COMPATIBLE, err);
                fdt = NULL;
        }

        return fdt;
}

static bool __init reserve_mem_kho_revive(const char *name, phys_addr_t size,
                                          phys_addr_t align)
{
        int err, len_start, len_size, offset;
        const phys_addr_t *p_start, *p_size;
        const void *fdt;

        fdt = reserve_mem_kho_retrieve_fdt();
        if (!fdt)
                return false;

        offset = fdt_subnode_offset(fdt, 0, name);
        if (offset < 0) {
                pr_warn("FDT '%s' has no child '%s': %d\n",
                        MEMBLOCK_KHO_FDT, name, offset);
                return false;
        }
        err = fdt_node_check_compatible(fdt, offset, RESERVE_MEM_KHO_NODE_COMPATIBLE);
        if (err) {
                pr_warn("Node '%s' is incompatible with '%s': %d\n",
                        name, RESERVE_MEM_KHO_NODE_COMPATIBLE, err);
                return false;
        }

        p_start = fdt_getprop(fdt, offset, "start", &len_start);
        p_size = fdt_getprop(fdt, offset, "size", &len_size);
        if (!p_start || len_start != sizeof(*p_start) || !p_size ||
            len_size != sizeof(*p_size)) {
                return false;
        }

        if (*p_start & (align - 1)) {
                pr_warn("KHO reserve-mem '%s' has wrong alignment (0x%lx, 0x%lx)\n",
                        name, (long)align, (long)*p_start);
                return false;
        }

        if (*p_size != size) {
                pr_warn("KHO reserve-mem '%s' has wrong size (0x%lx != 0x%lx)\n",
                        name, (long)*p_size, (long)size);
                return false;
        }

        reserved_mem_add(*p_start, size, name);
        pr_info("Revived memory reservation '%s' from KHO\n", name);

        return true;
}
#else
static bool __init reserve_mem_kho_revive(const char *name, phys_addr_t size,
                                          phys_addr_t align)
{
        return false;
}
#endif /* CONFIG_KEXEC_HANDOVER */

/*
 * Parse reserve_mem=nn:align:name
 */
static int __init reserve_mem(char *p)
{
        phys_addr_t start, size, align, tmp;
        char *name;
        char *oldp;
        int len;

        if (!p)
                return -EINVAL;

        /* Check if there's room for more reserved memory */
        if (reserved_mem_count >= RESERVE_MEM_MAX_ENTRIES)
                return -EBUSY;

        oldp = p;
        size = memparse(p, &p);
        if (!size || p == oldp)
                return -EINVAL;

        if (*p != ':')
                return -EINVAL;

        align = memparse(p+1, &p);
        if (*p != ':')
                return -EINVAL;

        /*
         * memblock_phys_alloc() doesn't like a zero size align,
         * but it is OK for this command to have it.
         */
        if (align < SMP_CACHE_BYTES)
                align = SMP_CACHE_BYTES;

        name = p + 1;
        len = strlen(name);

        /* name needs to have length but not too big */
        if (!len || len >= RESERVE_MEM_NAME_SIZE)
                return -EINVAL;

        /* Make sure that name has text */
        for (p = name; *p; p++) {
                if (!isspace(*p))
                        break;
        }
        if (!*p)
                return -EINVAL;

        /* Make sure the name is not already used */
        if (reserve_mem_find_by_name(name, &start, &tmp))
                return -EBUSY;

        /* Pick previous allocations up from KHO if available */
        if (reserve_mem_kho_revive(name, size, align))
                return 1;

        /* TODO: Allocation must be outside of scratch region */
        start = memblock_phys_alloc(size, align);
        if (!start)
                return -ENOMEM;

        reserved_mem_add(start, size, name);

        return 1;
}
__setup("reserve_mem=", reserve_mem);

#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_ARCH_KEEP_MEMBLOCK)
static const char * const flagname[] = {
        [ilog2(MEMBLOCK_HOTPLUG)] = "HOTPLUG",
        [ilog2(MEMBLOCK_MIRROR)] = "MIRROR",
        [ilog2(MEMBLOCK_NOMAP)] = "NOMAP",
        [ilog2(MEMBLOCK_DRIVER_MANAGED)] = "DRV_MNG",
        [ilog2(MEMBLOCK_RSRV_NOINIT)] = "RSV_NIT",
        [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN",
        [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH",
};

static int memblock_debug_show(struct seq_file *m, void *private)
{
        struct memblock_type *type = m->private;
        struct memblock_region *reg;
        int i, j, nid;
        unsigned int count = ARRAY_SIZE(flagname);
        phys_addr_t end;

        for (i = 0; i < type->cnt; i++) {
                reg = &type->regions[i];
                end = reg->base + reg->size - 1;
                nid = memblock_get_region_node(reg);

                seq_printf(m, "%4d: ", i);
                seq_printf(m, "%pa..%pa ", &reg->base, &end);
                if (numa_valid_node(nid))
                        seq_printf(m, "%4d ", nid);
                else
                        seq_printf(m, "%4c ", 'x');
                if (reg->flags) {
                        for (j = 0; j < count; j++) {
                                if (reg->flags & (1U << j)) {
                                        seq_printf(m, "%s\n", flagname[j]);
                                        break;
                                }
                        }
                        if (j == count)
                                seq_printf(m, "%s\n", "UNKNOWN");
                } else {
                        seq_printf(m, "%s\n", "NONE");
                }
        }
        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 */