// SPDX-License-Identifier: GPL-2.0+
/*
 *  EFI application memory management
 *
 *  Copyright (c) 2016 Alexander Graf
 */

#include <common.h>
#include <efi_loader.h>
#include <init.h>
#include <malloc.h>
#include <mapmem.h>
#include <watchdog.h>
#include <asm/cache.h>
#include <asm/global_data.h>
#include <linux/list_sort.h>
#include <linux/sizes.h>

DECLARE_GLOBAL_DATA_PTR;

/* Magic number identifying memory allocated from pool */
#define EFI_ALLOC_POOL_MAGIC 0x1fe67ddf6491caa2

efi_uintn_t efi_memory_map_key;

struct efi_mem_list {
        struct list_head link;
        struct efi_mem_desc desc;
};

#define EFI_CARVE_NO_OVERLAP            -1
#define EFI_CARVE_LOOP_AGAIN            -2
#define EFI_CARVE_OVERLAPS_NONRAM       -3

/* This list contains all memory map items */
LIST_HEAD(efi_mem);

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
void *efi_bounce_buffer;
#endif

/**
 * struct efi_pool_allocation - memory block allocated from pool
 *
 * @num_pages:  number of pages allocated
 * @checksum:   checksum
 * @data:       allocated pool memory
 *
 * U-Boot services each UEFI AllocatePool() request as a separate
 * (multiple) page allocation. We have to track the number of pages
 * to be able to free the correct amount later.
 *
 * The checksum calculated in function checksum() is used in FreePool() to avoid
 * freeing memory not allocated by AllocatePool() and duplicate freeing.
 *
 * EFI requires 8 byte alignment for pool allocations, so we can
 * prepend each allocation with these header fields.
 */
struct efi_pool_allocation {
        u64 num_pages;
        u64 checksum;
        char data[] __aligned(ARCH_DMA_MINALIGN);
};

/**
 * checksum() - calculate checksum for memory allocated from pool
 *
 * @alloc:      allocation header
 * Return:      checksum, always non-zero
 */
static u64 checksum(struct efi_pool_allocation *alloc)
{
        u64 addr = (uintptr_t)alloc;
        u64 ret = (addr >> 32) ^ (addr << 32) ^ alloc->num_pages ^
                  EFI_ALLOC_POOL_MAGIC;
        if (!ret)
                ++ret;
        return ret;
}

/*
 * Sorts the memory list from highest address to lowest address
 *
 * When allocating memory we should always start from the highest
 * address chunk, so sort the memory list such that the first list
 * iterator gets the highest address and goes lower from there.
 */
static int efi_mem_cmp(void *priv, struct list_head *a, struct list_head *b)
{
        struct efi_mem_list *mema = list_entry(a, struct efi_mem_list, link);
        struct efi_mem_list *memb = list_entry(b, struct efi_mem_list, link);

        if (mema->desc.physical_start == memb->desc.physical_start)
                return 0;
        else if (mema->desc.physical_start < memb->desc.physical_start)
                return 1;
        else
                return -1;
}

static uint64_t desc_get_end(struct efi_mem_desc *desc)
{
        return desc->physical_start + (desc->num_pages << EFI_PAGE_SHIFT);
}

static void efi_mem_sort(void)
{
        struct list_head *lhandle;
        struct efi_mem_list *prevmem = NULL;
        bool merge_again = true;

        list_sort(NULL, &efi_mem, efi_mem_cmp);

        /* Now merge entries that can be merged */
        while (merge_again) {
                merge_again = false;
                list_for_each(lhandle, &efi_mem) {
                        struct efi_mem_list *lmem;
                        struct efi_mem_desc *prev = &prevmem->desc;
                        struct efi_mem_desc *cur;
                        uint64_t pages;

                        lmem = list_entry(lhandle, struct efi_mem_list, link);
                        if (!prevmem) {
                                prevmem = lmem;
                                continue;
                        }

                        cur = &lmem->desc;

                        if ((desc_get_end(cur) == prev->physical_start) &&
                            (prev->type == cur->type) &&
                            (prev->attribute == cur->attribute)) {
                                /* There is an existing map before, reuse it */
                                pages = cur->num_pages;
                                prev->num_pages += pages;
                                prev->physical_start -= pages << EFI_PAGE_SHIFT;
                                prev->virtual_start -= pages << EFI_PAGE_SHIFT;
                                list_del(&lmem->link);
                                free(lmem);

                                merge_again = true;
                                break;
                        }

                        prevmem = lmem;
                }
        }
}

/** efi_mem_carve_out - unmap memory region
 *
 * @map:                memory map
 * @carve_desc:         memory region to unmap
 * @overlap_only_ram:   the carved out region may only overlap RAM
 * Return Value:        the number of overlapping pages which have been
 *                      removed from the map,
 *                      EFI_CARVE_NO_OVERLAP, if the regions don't overlap,
 *                      EFI_CARVE_OVERLAPS_NONRAM, if the carve and map overlap,
 *                      and the map contains anything but free ram
 *                      (only when overlap_only_ram is true),
 *                      EFI_CARVE_LOOP_AGAIN, if the mapping list should be
 *                      traversed again, as it has been altered.
 *
 * Unmaps all memory occupied by the carve_desc region from the list entry
 * pointed to by map.
 *
 * In case of EFI_CARVE_OVERLAPS_NONRAM it is the callers responsibility
 * to re-add the already carved out pages to the mapping.
 */
static s64 efi_mem_carve_out(struct efi_mem_list *map,
                             struct efi_mem_desc *carve_desc,
                             bool overlap_only_ram)
{
        struct efi_mem_list *newmap;
        struct efi_mem_desc *map_desc = &map->desc;
        uint64_t map_start = map_desc->physical_start;
        uint64_t map_end = map_start + (map_desc->num_pages << EFI_PAGE_SHIFT);
        uint64_t carve_start = carve_desc->physical_start;
        uint64_t carve_end = carve_start +
                             (carve_desc->num_pages << EFI_PAGE_SHIFT);

        /* check whether we're overlapping */
        if ((carve_end <= map_start) || (carve_start >= map_end))
                return EFI_CARVE_NO_OVERLAP;

        /* We're overlapping with non-RAM, warn the caller if desired */
        if (overlap_only_ram && (map_desc->type != EFI_CONVENTIONAL_MEMORY))
                return EFI_CARVE_OVERLAPS_NONRAM;

        /* Sanitize carve_start and carve_end to lie within our bounds */
        carve_start = max(carve_start, map_start);
        carve_end = min(carve_end, map_end);

        /* Carving at the beginning of our map? Just move it! */
        if (carve_start == map_start) {
                if (map_end == carve_end) {
                        /* Full overlap, just remove map */
                        list_del(&map->link);
                        free(map);
                } else {
                        map->desc.physical_start = carve_end;
                        map->desc.virtual_start = carve_end;
                        map->desc.num_pages = (map_end - carve_end)
                                              >> EFI_PAGE_SHIFT;
                }

                return (carve_end - carve_start) >> EFI_PAGE_SHIFT;
        }

        /*
         * Overlapping maps, just split the list map at carve_start,
         * it will get moved or removed in the next iteration.
         *
         * [ map_desc |__carve_start__| newmap ]
         */

        /* Create a new map from [ carve_start ... map_end ] */
        newmap = calloc(1, sizeof(*newmap));
        newmap->desc = map->desc;
        newmap->desc.physical_start = carve_start;
        newmap->desc.virtual_start = carve_start;
        newmap->desc.num_pages = (map_end - carve_start) >> EFI_PAGE_SHIFT;
        /* Insert before current entry (descending address order) */
        list_add_tail(&newmap->link, &map->link);

        /* Shrink the map to [ map_start ... carve_start ] */
        map_desc->num_pages = (carve_start - map_start) >> EFI_PAGE_SHIFT;

        return EFI_CARVE_LOOP_AGAIN;
}

/**
 * efi_add_memory_map_pg() - add pages to the memory map
 *
 * @start:              start address, must be a multiple of EFI_PAGE_SIZE
 * @pages:              number of pages to add
 * @memory_type:        type of memory added
 * @overlap_only_ram:   region may only overlap RAM
 * Return:              status code
 */
static efi_status_t efi_add_memory_map_pg(u64 start, u64 pages,
                                          int memory_type,
                                          bool overlap_only_ram)
{
        struct list_head *lhandle;
        struct efi_mem_list *newlist;
        bool carve_again;
        uint64_t carved_pages = 0;
        struct efi_event *evt;

        EFI_PRINT("%s: 0x%llx 0x%llx %d %s\n", __func__,
                  start, pages, memory_type, overlap_only_ram ? "yes" : "no");

        if (memory_type >= EFI_MAX_MEMORY_TYPE)
                return EFI_INVALID_PARAMETER;

        if (!pages)
                return EFI_SUCCESS;

        ++efi_memory_map_key;
        newlist = calloc(1, sizeof(*newlist));
        newlist->desc.type = memory_type;
        newlist->desc.physical_start = start;
        newlist->desc.virtual_start = start;
        newlist->desc.num_pages = pages;

        switch (memory_type) {
        case EFI_RUNTIME_SERVICES_CODE:
        case EFI_RUNTIME_SERVICES_DATA:
                newlist->desc.attribute = EFI_MEMORY_WB | EFI_MEMORY_RUNTIME;
                break;
        case EFI_MMAP_IO:
                newlist->desc.attribute = EFI_MEMORY_RUNTIME;
                break;
        default:
                newlist->desc.attribute = EFI_MEMORY_WB;
                break;
        }

        /* Add our new map */
        do {
                carve_again = false;
                list_for_each(lhandle, &efi_mem) {
                        struct efi_mem_list *lmem;
                        s64 r;

                        lmem = list_entry(lhandle, struct efi_mem_list, link);
                        r = efi_mem_carve_out(lmem, &newlist->desc,
                                              overlap_only_ram);
                        switch (r) {
                        case EFI_CARVE_OVERLAPS_NONRAM:
                                /*
                                 * The user requested to only have RAM overlaps,
                                 * but we hit a non-RAM region. Error out.
                                 */
                                return EFI_NO_MAPPING;
                        case EFI_CARVE_NO_OVERLAP:
                                /* Just ignore this list entry */
                                break;
                        case EFI_CARVE_LOOP_AGAIN:
                                /*
                                 * We split an entry, but need to loop through
                                 * the list again to actually carve it.
                                 */
                                carve_again = true;
                                break;
                        default:
                                /* We carved a number of pages */
                                carved_pages += r;
                                carve_again = true;
                                break;
                        }

                        if (carve_again) {
                                /* The list changed, we need to start over */
                                break;
                        }
                }
        } while (carve_again);

        if (overlap_only_ram && (carved_pages != pages)) {
                /*
                 * The payload wanted to have RAM overlaps, but we overlapped
                 * with an unallocated region. Error out.
                 */
                return EFI_NO_MAPPING;
        }

        /* Add our new map */
        list_add_tail(&newlist->link, &efi_mem);

        /* And make sure memory is listed in descending order */
        efi_mem_sort();

        /* Notify that the memory map was changed */
        list_for_each_entry(evt, &efi_events, link) {
                if (evt->group &&
                    !guidcmp(evt->group,
                             &efi_guid_event_group_memory_map_change)) {
                        efi_signal_event(evt);
                        break;
                }
        }

        return EFI_SUCCESS;
}

/**
 * efi_add_memory_map() - add memory area to the memory map
 *
 * @start:              start address of the memory area
 * @size:               length in bytes of the memory area
 * @memory_type:        type of memory added
 *
 * Return:              status code
 *
 * This function automatically aligns the start and size of the memory area
 * to EFI_PAGE_SIZE.
 */
efi_status_t efi_add_memory_map(u64 start, u64 size, int memory_type)
{
        u64 pages;

        pages = efi_size_in_pages(size + (start & EFI_PAGE_MASK));
        start &= ~EFI_PAGE_MASK;

        return efi_add_memory_map_pg(start, pages, memory_type, false);
}

/**
 * efi_check_allocated() - validate address to be freed
 *
 * Check that the address is within allocated memory:
 *
 * * The address must be in a range of the memory map.
 * * The address may not point to EFI_CONVENTIONAL_MEMORY.
 *
 * Page alignment is not checked as this is not a requirement of
 * efi_free_pool().
 *
 * @addr:               address of page to be freed
 * @must_be_allocated:  return success if the page is allocated
 * Return:              status code
 */
static efi_status_t efi_check_allocated(u64 addr, bool must_be_allocated)
{
        struct efi_mem_list *item;

        list_for_each_entry(item, &efi_mem, link) {
                u64 start = item->desc.physical_start;
                u64 end = start + (item->desc.num_pages << EFI_PAGE_SHIFT);

                if (addr >= start && addr < end) {
                        if (must_be_allocated ^
                            (item->desc.type == EFI_CONVENTIONAL_MEMORY))
                                return EFI_SUCCESS;
                        else
                                return EFI_NOT_FOUND;
                }
        }

        return EFI_NOT_FOUND;
}

static uint64_t efi_find_free_memory(uint64_t len, uint64_t max_addr)
{
        struct list_head *lhandle;

        /*
         * Prealign input max address, so we simplify our matching
         * logic below and can just reuse it as return pointer.
         */
        max_addr &= ~EFI_PAGE_MASK;

        list_for_each(lhandle, &efi_mem) {
                struct efi_mem_list *lmem = list_entry(lhandle,
                        struct efi_mem_list, link);
                struct efi_mem_desc *desc = &lmem->desc;
                uint64_t desc_len = desc->num_pages << EFI_PAGE_SHIFT;
                uint64_t desc_end = desc->physical_start + desc_len;
                uint64_t curmax = min(max_addr, desc_end);
                uint64_t ret = curmax - len;

                /* We only take memory from free RAM */
                if (desc->type != EFI_CONVENTIONAL_MEMORY)
                        continue;

                /* Out of bounds for max_addr */
                if ((ret + len) > max_addr)
                        continue;

                /* Out of bounds for upper map limit */
                if ((ret + len) > desc_end)
                        continue;

                /* Out of bounds for lower map limit */
                if (ret < desc->physical_start)
                        continue;

                /* Return the highest address in this map within bounds */
                return ret;
        }

        return 0;
}

/*
 * Allocate memory pages.
 *
 * @type                type of allocation to be performed
 * @memory_type         usage type of the allocated memory
 * @pages               number of pages to be allocated
 * @memory              allocated memory
 * Return:              status code
 */
efi_status_t efi_allocate_pages(enum efi_allocate_type type,
                                enum efi_memory_type memory_type,
                                efi_uintn_t pages, uint64_t *memory)
{
        u64 len = pages << EFI_PAGE_SHIFT;
        efi_status_t ret;
        uint64_t addr;

        /* Check import parameters */
        if (memory_type >= EFI_PERSISTENT_MEMORY_TYPE &&
            memory_type <= 0x6FFFFFFF)
                return EFI_INVALID_PARAMETER;
        if (!memory)
                return EFI_INVALID_PARAMETER;

        switch (type) {
        case EFI_ALLOCATE_ANY_PAGES:
                /* Any page */
                addr = efi_find_free_memory(len, -1ULL);
                if (!addr)
                        return EFI_OUT_OF_RESOURCES;
                break;
        case EFI_ALLOCATE_MAX_ADDRESS:
                /* Max address */
                addr = efi_find_free_memory(len, *memory);
                if (!addr)
                        return EFI_OUT_OF_RESOURCES;
                break;
        case EFI_ALLOCATE_ADDRESS:
                /* Exact address, reserve it. The addr is already in *memory. */
                ret = efi_check_allocated(*memory, false);
                if (ret != EFI_SUCCESS)
                        return EFI_NOT_FOUND;
                addr = *memory;
                break;
        default:
                /* UEFI doesn't specify other allocation types */
                return EFI_INVALID_PARAMETER;
        }

        /* Reserve that map in our memory maps */
        ret = efi_add_memory_map_pg(addr, pages, memory_type, true);
        if (ret != EFI_SUCCESS)
                /* Map would overlap, bail out */
                return  EFI_OUT_OF_RESOURCES;

        *memory = addr;

        return EFI_SUCCESS;
}

void *efi_alloc(uint64_t len, int memory_type)
{
        uint64_t ret = 0;
        uint64_t pages = efi_size_in_pages(len);
        efi_status_t r;

        r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages,
                               &ret);
        if (r == EFI_SUCCESS)
                return (void*)(uintptr_t)ret;

        return NULL;
}

/**
 * efi_free_pages() - free memory pages
 *
 * @memory:     start of the memory area to be freed
 * @pages:      number of pages to be freed
 * Return:      status code
 */
efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
{
        efi_status_t ret;

        ret = efi_check_allocated(memory, true);
        if (ret != EFI_SUCCESS)
                return ret;

        /* Sanity check */
        if (!memory || (memory & EFI_PAGE_MASK) || !pages) {
                printf("%s: illegal free 0x%llx, 0x%zx\n", __func__,
                       memory, pages);
                return EFI_INVALID_PARAMETER;
        }

        ret = efi_add_memory_map_pg(memory, pages, EFI_CONVENTIONAL_MEMORY,
                                    false);
        if (ret != EFI_SUCCESS)
                return EFI_NOT_FOUND;

        return ret;
}

/**
 * efi_alloc_aligned_pages - allocate
 *
 * @len:                len in bytes
 * @memory_type:        usage type of the allocated memory
 * @align:              alignment in bytes
 * Return:              aligned memory or NULL
 */
void *efi_alloc_aligned_pages(u64 len, int memory_type, size_t align)
{
        u64 req_pages = efi_size_in_pages(len);
        u64 true_pages = req_pages + efi_size_in_pages(align) - 1;
        u64 free_pages;
        u64 aligned_mem;
        efi_status_t r;
        u64 mem;

        /* align must be zero or a power of two */
        if (align & (align - 1))
                return NULL;

        /* Check for overflow */
        if (true_pages < req_pages)
                return NULL;

        if (align < EFI_PAGE_SIZE) {
                r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type,
                                       req_pages, &mem);
                return (r == EFI_SUCCESS) ? (void *)(uintptr_t)mem : NULL;
        }

        r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type,
                               true_pages, &mem);
        if (r != EFI_SUCCESS)
                return NULL;

        aligned_mem = ALIGN(mem, align);
        /* Free pages before alignment */
        free_pages = efi_size_in_pages(aligned_mem - mem);
        if (free_pages)
                efi_free_pages(mem, free_pages);

        /* Free trailing pages */
        free_pages = true_pages - (req_pages + free_pages);
        if (free_pages) {
                mem = aligned_mem + req_pages * EFI_PAGE_SIZE;
                efi_free_pages(mem, free_pages);
        }

        return (void *)(uintptr_t)aligned_mem;
}

/**
 * efi_allocate_pool - allocate memory from pool
 *
 * @pool_type:  type of the pool from which memory is to be allocated
 * @size:       number of bytes to be allocated
 * @buffer:     allocated memory
 * Return:      status code
 */
efi_status_t efi_allocate_pool(enum efi_memory_type pool_type, efi_uintn_t size, void **buffer)
{
        efi_status_t r;
        u64 addr;
        struct efi_pool_allocation *alloc;
        u64 num_pages = efi_size_in_pages(size +
                                          sizeof(struct efi_pool_allocation));

        if (!buffer)
                return EFI_INVALID_PARAMETER;

        if (size == 0) {
                *buffer = NULL;
                return EFI_SUCCESS;
        }

        r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, pool_type, num_pages,
                               &addr);
        if (r == EFI_SUCCESS) {
                alloc = (struct efi_pool_allocation *)(uintptr_t)addr;
                alloc->num_pages = num_pages;
                alloc->checksum = checksum(alloc);
                *buffer = alloc->data;
        }

        return r;
}

/**
 * efi_free_pool() - free memory from pool
 *
 * @buffer:     start of memory to be freed
 * Return:      status code
 */
efi_status_t efi_free_pool(void *buffer)
{
        efi_status_t ret;
        struct efi_pool_allocation *alloc;

        if (!buffer)
                return EFI_INVALID_PARAMETER;

        ret = efi_check_allocated((uintptr_t)buffer, true);
        if (ret != EFI_SUCCESS)
                return ret;

        alloc = container_of(buffer, struct efi_pool_allocation, data);

        /* Check that this memory was allocated by efi_allocate_pool() */
        if (((uintptr_t)alloc & EFI_PAGE_MASK) ||
            alloc->checksum != checksum(alloc)) {
                printf("%s: illegal free 0x%p\n", __func__, buffer);
                return EFI_INVALID_PARAMETER;
        }
        /* Avoid double free */
        alloc->checksum = 0;

        ret = efi_free_pages((uintptr_t)alloc, alloc->num_pages);

        return ret;
}

/*
 * Get map describing memory usage.
 *
 * @memory_map_size     on entry the size, in bytes, of the memory map buffer,
 *                      on exit the size of the copied memory map
 * @memory_map          buffer to which the memory map is written
 * @map_key             key for the memory map
 * @descriptor_size     size of an individual memory descriptor
 * @descriptor_version  version number of the memory descriptor structure
 * Return:              status code
 */
efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
                                struct efi_mem_desc *memory_map,
                                efi_uintn_t *map_key,
                                efi_uintn_t *descriptor_size,
                                uint32_t *descriptor_version)
{
        efi_uintn_t map_size = 0;
        int map_entries = 0;
        struct list_head *lhandle;
        efi_uintn_t provided_map_size;

        if (!memory_map_size)
                return EFI_INVALID_PARAMETER;

        provided_map_size = *memory_map_size;

        list_for_each(lhandle, &efi_mem)
                map_entries++;

        map_size = map_entries * sizeof(struct efi_mem_desc);

        *memory_map_size = map_size;

        if (descriptor_size)
                *descriptor_size = sizeof(struct efi_mem_desc);

        if (descriptor_version)
                *descriptor_version = EFI_MEMORY_DESCRIPTOR_VERSION;

        if (provided_map_size < map_size)
                return EFI_BUFFER_TOO_SMALL;

        if (!memory_map)
                return EFI_INVALID_PARAMETER;

        /* Copy list into array */
        /* Return the list in ascending order */
        memory_map = &memory_map[map_entries - 1];
        list_for_each(lhandle, &efi_mem) {
                struct efi_mem_list *lmem;

                lmem = list_entry(lhandle, struct efi_mem_list, link);
                *memory_map = lmem->desc;
                memory_map--;
        }

        if (map_key)
                *map_key = efi_memory_map_key;

        return EFI_SUCCESS;
}

/**
 * efi_add_conventional_memory_map() - add a RAM memory area to the map
 *
 * @ram_start:          start address of a RAM memory area
 * @ram_end:            end address of a RAM memory area
 * @ram_top:            max address to be used as conventional memory
 * Return:              status code
 */
efi_status_t efi_add_conventional_memory_map(u64 ram_start, u64 ram_end,
                                             u64 ram_top)
{
        u64 pages;

        /* Remove partial pages */
        ram_end &= ~EFI_PAGE_MASK;
        ram_start = (ram_start + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;

        if (ram_end <= ram_start) {
                /* Invalid mapping */
                return EFI_INVALID_PARAMETER;
        }

        pages = (ram_end - ram_start) >> EFI_PAGE_SHIFT;

        efi_add_memory_map_pg(ram_start, pages,
                              EFI_CONVENTIONAL_MEMORY, false);

        /*
         * Boards may indicate to the U-Boot memory core that they
         * can not support memory above ram_top. Let's honor this
         * in the efi_loader subsystem too by declaring any memory
         * above ram_top as "already occupied by firmware".
         */
        if (ram_top < ram_start) {
                /* ram_top is before this region, reserve all */
                efi_add_memory_map_pg(ram_start, pages,
                                      EFI_BOOT_SERVICES_DATA, true);
        } else if (ram_top < ram_end) {
                /* ram_top is inside this region, reserve parts */
                pages = (ram_end - ram_top) >> EFI_PAGE_SHIFT;

                efi_add_memory_map_pg(ram_top, pages,
                                      EFI_BOOT_SERVICES_DATA, true);
        }

        return EFI_SUCCESS;
}

__weak void efi_add_known_memory(void)
{
        u64 ram_top = board_get_usable_ram_top(0) & ~EFI_PAGE_MASK;
        int i;

        /*
         * ram_top is just outside mapped memory. So use an offset of one for
         * mapping the sandbox address.
         */
        ram_top = (uintptr_t)map_sysmem(ram_top - 1, 0) + 1;

        /* Fix for 32bit targets with ram_top at 4G */
        if (!ram_top)
                ram_top = 0x100000000ULL;

        /* Add RAM */
        for (i = 0; i < CONFIG_NR_DRAM_BANKS; i++) {
                u64 ram_end, ram_start;

                ram_start = (uintptr_t)map_sysmem(gd->bd->bi_dram[i].start, 0);
                ram_end = ram_start + gd->bd->bi_dram[i].size;

                efi_add_conventional_memory_map(ram_start, ram_end, ram_top);
        }
}

/* Add memory regions for U-Boot's memory and for the runtime services code */
static void add_u_boot_and_runtime(void)
{
        unsigned long runtime_start, runtime_end, runtime_pages;
        unsigned long runtime_mask = EFI_PAGE_MASK;
        unsigned long uboot_start, uboot_pages;
        unsigned long uboot_stack_size = CONFIG_STACK_SIZE;

        /* Add U-Boot */
        uboot_start = ((uintptr_t)map_sysmem(gd->start_addr_sp, 0) -
                       uboot_stack_size) & ~EFI_PAGE_MASK;
        uboot_pages = ((uintptr_t)map_sysmem(gd->ram_top - 1, 0) -
                       uboot_start + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
        efi_add_memory_map_pg(uboot_start, uboot_pages, EFI_LOADER_DATA,
                              false);

#if defined(__aarch64__)
        /*
         * Runtime Services must be 64KiB aligned according to the
         * "AArch64 Platforms" section in the UEFI spec (2.7+).
         */

        runtime_mask = SZ_64K - 1;
#endif

        /*
         * Add Runtime Services. We mark surrounding boottime code as runtime as
         * well to fulfill the runtime alignment constraints but avoid padding.
         */
        runtime_start = (ulong)&__efi_runtime_start & ~runtime_mask;
        runtime_end = (ulong)&__efi_runtime_stop;
        runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
        runtime_pages = (runtime_end - runtime_start) >> EFI_PAGE_SHIFT;
        efi_add_memory_map_pg(runtime_start, runtime_pages,
                              EFI_RUNTIME_SERVICES_CODE, false);
}

int efi_memory_init(void)
{
        efi_add_known_memory();

        add_u_boot_and_runtime();

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
        /* Request a 32bit 64MB bounce buffer region */
        uint64_t efi_bounce_buffer_addr = 0xffffffff;

        if (efi_allocate_pages(EFI_ALLOCATE_MAX_ADDRESS, EFI_LOADER_DATA,
                               (64 * 1024 * 1024) >> EFI_PAGE_SHIFT,
                               &efi_bounce_buffer_addr) != EFI_SUCCESS)
                return -1;

        efi_bounce_buffer = (void*)(uintptr_t)efi_bounce_buffer_addr;
#endif

        return 0;
}