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

#define LOG_CATEGORY LOGC_EFI

#include <common.h>
#include <blk.h>
#include <dm.h>
#include <dm/device-internal.h>
#include <dm/tag.h>
#include <event.h>
#include <efi_driver.h>
#include <efi_loader.h>
#include <fs.h>
#include <log.h>
#include <part.h>
#include <malloc.h>

struct efi_system_partition efi_system_partition = {
        .uclass_id = UCLASS_INVALID,
};

const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;
const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID;

/**
 * struct efi_disk_obj - EFI disk object
 *
 * @header:     EFI object header
 * @ops:        EFI disk I/O protocol interface
 * @dev_index:  device index of block device
 * @media:      block I/O media information
 * @dp:         device path to the block device
 * @part:       partition
 * @volume:     simple file system protocol of the partition
 * @dev:        associated DM device
 */
struct efi_disk_obj {
        struct efi_object header;
        struct efi_block_io ops;
        int dev_index;
        struct efi_block_io_media media;
        struct efi_device_path *dp;
        unsigned int part;
        struct efi_simple_file_system_protocol *volume;
};

/**
 * efi_disk_reset() - reset block device
 *
 * This function implements the Reset service of the EFI_BLOCK_IO_PROTOCOL.
 *
 * As U-Boot's block devices do not have a reset function simply return
 * EFI_SUCCESS.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @this:                       pointer to the BLOCK_IO_PROTOCOL
 * @extended_verification:      extended verification
 * Return:                      status code
 */
static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
                        char extended_verification)
{
        EFI_ENTRY("%p, %x", this, extended_verification);
        return EFI_EXIT(EFI_SUCCESS);
}

/**
 * efi_disk_is_removable() - check if the device is removable media
 * @handle:             efi object handle;
 *
 * Examine the device and determine if the device is a local block device
 * and removable media.
 *
 * Return:              true if removable, false otherwise
 */
bool efi_disk_is_removable(efi_handle_t handle)
{
        struct efi_handler *handler;
        struct efi_block_io *io;
        efi_status_t ret;

        ret = efi_search_protocol(handle, &efi_block_io_guid, &handler);
        if (ret != EFI_SUCCESS)
                return false;

        io = handler->protocol_interface;

        if (!io || !io->media)
                return false;

        return (bool)io->media->removable_media;
}

enum efi_disk_direction {
        EFI_DISK_READ,
        EFI_DISK_WRITE,
};

static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
                        u32 media_id, u64 lba, unsigned long buffer_size,
                        void *buffer, enum efi_disk_direction direction)
{
        struct efi_disk_obj *diskobj;
        int blksz;
        int blocks;
        unsigned long n;

        diskobj = container_of(this, struct efi_disk_obj, ops);
        blksz = diskobj->media.block_size;
        blocks = buffer_size / blksz;

        EFI_PRINT("blocks=%x lba=%llx blksz=%x dir=%d\n",
                  blocks, lba, blksz, direction);

        /* We only support full block access */
        if (buffer_size & (blksz - 1))
                return EFI_BAD_BUFFER_SIZE;

        if (CONFIG_IS_ENABLED(PARTITIONS) &&
            device_get_uclass_id(diskobj->header.dev) == UCLASS_PARTITION) {
                if (direction == EFI_DISK_READ)
                        n = disk_blk_read(diskobj->header.dev, lba, blocks,
                                          buffer);
                else
                        n = disk_blk_write(diskobj->header.dev, lba, blocks,
                                           buffer);
        } else {
                /* dev is a block device (UCLASS_BLK) */
                struct blk_desc *desc;

                desc = dev_get_uclass_plat(diskobj->header.dev);
                if (direction == EFI_DISK_READ)
                        n = blk_dread(desc, lba, blocks, buffer);
                else
                        n = blk_dwrite(desc, lba, blocks, buffer);
        }

        /* We don't do interrupts, so check for timers cooperatively */
        efi_timer_check();

        EFI_PRINT("n=%lx blocks=%x\n", n, blocks);

        if (n != blocks)
                return EFI_DEVICE_ERROR;

        return EFI_SUCCESS;
}

/**
 * efi_disk_read_blocks() - reads blocks from device
 *
 * This function implements the ReadBlocks service of the EFI_BLOCK_IO_PROTOCOL.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @this:                       pointer to the BLOCK_IO_PROTOCOL
 * @media_id:                   id of the medium to be read from
 * @lba:                        starting logical block for reading
 * @buffer_size:                size of the read buffer
 * @buffer:                     pointer to the destination buffer
 * Return:                      status code
 */
static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
                        u32 media_id, u64 lba, efi_uintn_t buffer_size,
                        void *buffer)
{
        void *real_buffer = buffer;
        efi_status_t r;

        if (!this)
                return EFI_INVALID_PARAMETER;
        /* TODO: check for media changes */
        if (media_id != this->media->media_id)
                return EFI_MEDIA_CHANGED;
        if (!this->media->media_present)
                return EFI_NO_MEDIA;
        /* media->io_align is a power of 2 or 0 */
        if (this->media->io_align &&
            (uintptr_t)buffer & (this->media->io_align - 1))
                return EFI_INVALID_PARAMETER;
        if (lba * this->media->block_size + buffer_size >
            (this->media->last_block + 1) * this->media->block_size)
                return EFI_INVALID_PARAMETER;

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
        if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
                r = efi_disk_read_blocks(this, media_id, lba,
                        EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
                if (r != EFI_SUCCESS)
                        return r;
                return efi_disk_read_blocks(this, media_id, lba +
                        EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
                        buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
                        buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
        }

        real_buffer = efi_bounce_buffer;
#endif

        EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
                  buffer_size, buffer);

        r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
                               EFI_DISK_READ);

        /* Copy from bounce buffer to real buffer if necessary */
        if ((r == EFI_SUCCESS) && (real_buffer != buffer))
                memcpy(buffer, real_buffer, buffer_size);

        return EFI_EXIT(r);
}

/**
 * efi_disk_write_blocks() - writes blocks to device
 *
 * This function implements the WriteBlocks service of the
 * EFI_BLOCK_IO_PROTOCOL.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @this:                       pointer to the BLOCK_IO_PROTOCOL
 * @media_id:                   id of the medium to be written to
 * @lba:                        starting logical block for writing
 * @buffer_size:                size of the write buffer
 * @buffer:                     pointer to the source buffer
 * Return:                      status code
 */
static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
                        u32 media_id, u64 lba, efi_uintn_t buffer_size,
                        void *buffer)
{
        void *real_buffer = buffer;
        efi_status_t r;

        if (!this)
                return EFI_INVALID_PARAMETER;
        if (this->media->read_only)
                return EFI_WRITE_PROTECTED;
        /* TODO: check for media changes */
        if (media_id != this->media->media_id)
                return EFI_MEDIA_CHANGED;
        if (!this->media->media_present)
                return EFI_NO_MEDIA;
        /* media->io_align is a power of 2 or 0 */
        if (this->media->io_align &&
            (uintptr_t)buffer & (this->media->io_align - 1))
                return EFI_INVALID_PARAMETER;
        if (lba * this->media->block_size + buffer_size >
            (this->media->last_block + 1) * this->media->block_size)
                return EFI_INVALID_PARAMETER;

#ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
        if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
                r = efi_disk_write_blocks(this, media_id, lba,
                        EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
                if (r != EFI_SUCCESS)
                        return r;
                return efi_disk_write_blocks(this, media_id, lba +
                        EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
                        buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
                        buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
        }

        real_buffer = efi_bounce_buffer;
#endif

        EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
                  buffer_size, buffer);

        /* Populate bounce buffer if necessary */
        if (real_buffer != buffer)
                memcpy(real_buffer, buffer, buffer_size);

        r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
                               EFI_DISK_WRITE);

        return EFI_EXIT(r);
}

/**
 * efi_disk_flush_blocks() - flushes modified data to the device
 *
 * This function implements the FlushBlocks service of the
 * EFI_BLOCK_IO_PROTOCOL.
 *
 * As we always write synchronously nothing is done here.
 *
 * See the Unified Extensible Firmware Interface (UEFI) specification for
 * details.
 *
 * @this:                       pointer to the BLOCK_IO_PROTOCOL
 * Return:                      status code
 */
static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
{
        EFI_ENTRY("%p", this);
        return EFI_EXIT(EFI_SUCCESS);
}

static const struct efi_block_io block_io_disk_template = {
        .reset = &efi_disk_reset,
        .read_blocks = &efi_disk_read_blocks,
        .write_blocks = &efi_disk_write_blocks,
        .flush_blocks = &efi_disk_flush_blocks,
};

/**
 * efi_fs_from_path() - retrieve simple file system protocol
 *
 * Gets the simple file system protocol for a file device path.
 *
 * The full path provided is split into device part and into a file
 * part. The device part is used to find the handle on which the
 * simple file system protocol is installed.
 *
 * @full_path:  device path including device and file
 * Return:      simple file system protocol
 */
struct efi_simple_file_system_protocol *
efi_fs_from_path(struct efi_device_path *full_path)
{
        struct efi_object *efiobj;
        struct efi_handler *handler;
        struct efi_device_path *device_path;
        struct efi_device_path *file_path;
        efi_status_t ret;

        /* Split the path into a device part and a file part */
        ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
        if (ret != EFI_SUCCESS)
                return NULL;
        efi_free_pool(file_path);

        /* Get the EFI object for the partition */
        efiobj = efi_dp_find_obj(device_path, NULL, NULL);
        efi_free_pool(device_path);
        if (!efiobj)
                return NULL;

        /* Find the simple file system protocol */
        ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
                                  &handler);
        if (ret != EFI_SUCCESS)
                return NULL;

        /* Return the simple file system protocol for the partition */
        return handler->protocol_interface;
}

/**
 * efi_fs_exists() - check if a partition bears a file system
 *
 * @desc:       block device descriptor
 * @part:       partition number
 * Return:      1 if a file system exists on the partition
 *              0 otherwise
 */
static int efi_fs_exists(struct blk_desc *desc, int part)
{
        if (fs_set_blk_dev_with_part(desc, part))
                return 0;

        if (fs_get_type() == FS_TYPE_ANY)
                return 0;

        fs_close();

        return 1;
}

/**
 * efi_disk_add_dev() - create a handle for a partition or disk
 *
 * @parent:             parent handle
 * @dp_parent:          parent device path
 * @desc:               internal block device
 * @dev_index:          device index for block device
 * @part_info:          partition info
 * @part:               partition
 * @disk:               pointer to receive the created handle
 * @agent_handle:       handle of the EFI block driver
 * Return:              disk object
 */
static efi_status_t efi_disk_add_dev(
                                efi_handle_t parent,
                                struct efi_device_path *dp_parent,
                                struct blk_desc *desc,
                                int dev_index,
                                struct disk_partition *part_info,
                                unsigned int part,
                                struct efi_disk_obj **disk,
                                efi_handle_t agent_handle)
{
        struct efi_disk_obj *diskobj;
        struct efi_object *handle;
        const efi_guid_t *esp_guid = NULL;
        efi_status_t ret;

        /* Don't add empty devices */
        if (!desc->lba)
                return EFI_NOT_READY;

        diskobj = calloc(1, sizeof(*diskobj));
        if (!diskobj)
                return EFI_OUT_OF_RESOURCES;

        /* Hook up to the device list */
        efi_add_handle(&diskobj->header);

        /* Fill in object data */
        if (part_info) {
                struct efi_device_path *node = efi_dp_part_node(desc, part);
                struct efi_handler *handler;
                void *protocol_interface;

                if (!node) {
                        ret = EFI_OUT_OF_RESOURCES;
                        log_debug("no node\n");
                        goto error;
                }

                /* Parent must expose EFI_BLOCK_IO_PROTOCOL */
                ret = efi_search_protocol(parent, &efi_block_io_guid, &handler);
                if (ret != EFI_SUCCESS) {
                        log_debug("search failed\n");
                        goto error;
                }

                /*
                 * Link the partition (child controller) to the block device
                 * (controller).
                 */
                ret = efi_protocol_open(handler, &protocol_interface, NULL,
                                        &diskobj->header,
                                        EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER);
                if (ret != EFI_SUCCESS) {
                        log_debug("prot open failed\n");
                        goto error;
                }

                diskobj->dp = efi_dp_append_node(dp_parent, node);
                efi_free_pool(node);
                diskobj->media.last_block = part_info->size - 1;
                if (part_info->bootable & PART_EFI_SYSTEM_PARTITION)
                        esp_guid = &efi_system_partition_guid;
        } else {
                diskobj->dp = efi_dp_from_part(desc, part);
                diskobj->media.last_block = desc->lba - 1;
        }
        diskobj->part = part;

        /*
         * Install the device path and the block IO protocol.
         *
         * InstallMultipleProtocolInterfaces() checks if the device path is
         * already installed on an other handle and returns EFI_ALREADY_STARTED
         * in this case.
         */
        handle = &diskobj->header;
        ret = efi_install_multiple_protocol_interfaces(
                                        &handle,
                                        &efi_guid_device_path, diskobj->dp,
                                        &efi_block_io_guid, &diskobj->ops,
                                        /*
                                         * esp_guid must be last entry as it
                                         * can be NULL. Its interface is NULL.
                                         */
                                        esp_guid, NULL,
                                        NULL);
        if (ret != EFI_SUCCESS) {
                log_debug("install failed %lx\n", ret);
                goto error;
        }

        /*
         * On partitions or whole disks without partitions install the
         * simple file system protocol if a file system is available.
         */
        if ((part || desc->part_type == PART_TYPE_UNKNOWN) &&
            efi_fs_exists(desc, part)) {
                diskobj->volume = efi_simple_file_system(desc, part,
                                                         diskobj->dp);
                ret = efi_add_protocol(&diskobj->header,
                                       &efi_simple_file_system_protocol_guid,
                                       diskobj->volume);
                if (ret != EFI_SUCCESS) {
                        log_debug("simple FS failed\n");
                        return ret;
                }
        }
        diskobj->ops = block_io_disk_template;
        diskobj->dev_index = dev_index;

        /* Fill in EFI IO Media info (for read/write callbacks) */
        diskobj->media.removable_media = desc->removable;
        diskobj->media.media_present = 1;
        /*
         * MediaID is just an arbitrary counter.
         * We have to change it if the medium is removed or changed.
         */
        diskobj->media.media_id = 1;
        diskobj->media.block_size = desc->blksz;
        diskobj->media.io_align = desc->blksz;
        if (part)
                diskobj->media.logical_partition = 1;
        diskobj->ops.media = &diskobj->media;
        if (disk)
                *disk = diskobj;

        EFI_PRINT("BlockIO: part %u, present %d, logical %d, removable %d"
                  ", last_block %llu\n",
                  diskobj->part,
                  diskobj->media.media_present,
                  diskobj->media.logical_partition,
                  diskobj->media.removable_media,
                  diskobj->media.last_block);

        /* Store first EFI system partition */
        if (part && efi_system_partition.uclass_id == UCLASS_INVALID) {
                if (part_info->bootable & PART_EFI_SYSTEM_PARTITION) {
                        efi_system_partition.uclass_id = desc->uclass_id;
                        efi_system_partition.devnum = desc->devnum;
                        efi_system_partition.part = part;
                        EFI_PRINT("EFI system partition: %s %x:%x\n",
                                  blk_get_uclass_name(desc->uclass_id),
                                  desc->devnum, part);
                }
        }
        return EFI_SUCCESS;
error:
        efi_delete_handle(&diskobj->header);
        return ret;
}

/**
 * efi_disk_create_raw() - create a handle for a whole raw disk
 *
 * @dev:                udevice (UCLASS_BLK)
 * @agent_handle:       handle of the EFI block driver
 *
 * Create an efi_disk object which is associated with @dev.
 * The type of @dev must be UCLASS_BLK.
 *
 * Return:              0 on success, -1 otherwise
 */
static int efi_disk_create_raw(struct udevice *dev, efi_handle_t agent_handle)
{
        struct efi_disk_obj *disk;
        struct blk_desc *desc;
        int diskid;
        efi_status_t ret;

        desc = dev_get_uclass_plat(dev);
        diskid = desc->devnum;

        ret = efi_disk_add_dev(NULL, NULL, desc,
                               diskid, NULL, 0, &disk, agent_handle);
        if (ret != EFI_SUCCESS) {
                if (ret == EFI_NOT_READY) {
                        log_notice("Disk %s not ready\n", dev->name);
                        ret = -EBUSY;
                } else {
                        log_err("Adding disk for %s failed (err=%ld/%#lx)\n", dev->name, ret, ret);
                        ret = -ENOENT;
                }

                return ret;
        }
        if (efi_link_dev(&disk->header, dev)) {
                efi_free_pool(disk->dp);
                efi_delete_handle(&disk->header);

                return -EINVAL;
        }

        return 0;
}

/**
 * efi_disk_create_part() - create a handle for a disk partition
 *
 * @dev:                udevice (UCLASS_PARTITION)
 * @agent_handle:       handle of the EFI block driver
 *
 * Create an efi_disk object which is associated with @dev.
 * The type of @dev must be UCLASS_PARTITION.
 *
 * Return:              0 on success, -1 otherwise
 */
static int efi_disk_create_part(struct udevice *dev, efi_handle_t agent_handle)
{
        efi_handle_t parent;
        struct blk_desc *desc;
        struct disk_part *part_data;
        struct disk_partition *info;
        unsigned int part;
        int diskid;
        struct efi_handler *handler;
        struct efi_device_path *dp_parent;
        struct efi_disk_obj *disk;
        efi_status_t ret;

        if (dev_tag_get_ptr(dev_get_parent(dev), DM_TAG_EFI, (void **)&parent))
                return -1;

        desc = dev_get_uclass_plat(dev_get_parent(dev));
        diskid = desc->devnum;

        part_data = dev_get_uclass_plat(dev);
        part = part_data->partnum;
        info = &part_data->gpt_part_info;

        ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
        if (ret != EFI_SUCCESS)
                return -1;
        dp_parent = (struct efi_device_path *)handler->protocol_interface;

        ret = efi_disk_add_dev(parent, dp_parent, desc, diskid,
                               info, part, &disk, agent_handle);
        if (ret != EFI_SUCCESS) {
                log_err("Adding partition for %s failed\n", dev->name);
                return -1;
        }
        if (efi_link_dev(&disk->header, dev)) {
                efi_free_pool(disk->dp);
                efi_delete_handle(&disk->header);

                return -1;
        }

        return 0;
}

/**
 * efi_disk_probe() - create efi_disk objects for a block device
 *
 * @ctx:        event context - driver binding protocol
 * @event:      EV_PM_POST_PROBE event
 *
 * Create efi_disk objects for partitions as well as a raw disk
 * which is associated with @dev.
 * The type of @dev must be UCLASS_BLK.
 * This function is expected to be called at EV_PM_POST_PROBE.
 *
 * Return:      0 on success, -1 otherwise
 */
int efi_disk_probe(void *ctx, struct event *event)
{
        struct udevice *dev;
        enum uclass_id id;
        struct blk_desc *desc;
        struct udevice *child;
        struct efi_driver_binding_extended_protocol *db_prot = ctx;
        efi_handle_t agent_handle = db_prot->bp.driver_binding_handle;
        int ret;

        dev = event->data.dm.dev;
        id = device_get_uclass_id(dev);

        /* We won't support partitions in a partition */
        if (id != UCLASS_BLK)
                return 0;

        /*
         * Avoid creating duplicated objects now that efi_driver
         * has already created an efi_disk at this moment.
         */
        desc = dev_get_uclass_plat(dev);
        if (desc->uclass_id != UCLASS_EFI_LOADER) {
                ret = efi_disk_create_raw(dev, agent_handle);
                if (ret)
                        return -1;
        }

        device_foreach_child(child, dev) {
                ret = efi_disk_create_part(child, agent_handle);
                if (ret)
                        return -1;
        }

        return 0;
}

/**
 * efi_disk_remove - delete an efi_disk object for a block device or partition
 *
 * @ctx:        event context: driver binding protocol
 * @event:      EV_PM_PRE_REMOVE event
 *
 * Delete an efi_disk object which is associated with the UCLASS_BLK or
 * UCLASS_PARTITION device for which the EV_PM_PRE_REMOVE event is raised.
 *
 * Return:      0 on success, -1 otherwise
 */
int efi_disk_remove(void *ctx, struct event *event)
{
        enum uclass_id id;
        struct udevice *dev = event->data.dm.dev;
        efi_handle_t handle;
        struct blk_desc *desc;
        struct efi_disk_obj *diskobj = NULL;

        if (dev_tag_get_ptr(dev, DM_TAG_EFI, (void **)&handle))
                return 0;

        id = device_get_uclass_id(dev);
        switch (id) {
        case UCLASS_BLK:
                desc = dev_get_uclass_plat(dev);
                if (desc && desc->uclass_id != UCLASS_EFI_LOADER)
                        diskobj = container_of(handle, struct efi_disk_obj,
                                               header);
                break;
        case UCLASS_PARTITION:
                diskobj = container_of(handle, struct efi_disk_obj, header);
                break;
        default:
                return 0;
        }

        if (diskobj)
                efi_free_pool(diskobj->dp);

        efi_delete_handle(handle);
        dev_tag_del(dev, DM_TAG_EFI);

        return 0;
}

/**
 * efi_disk_get_device_name() - get U-Boot device name associated with EFI handle
 *
 * @handle:     pointer to the EFI handle
 * @buf:        pointer to the buffer to store the string
 * @size:       size of buffer
 * Return:      status code
 */
efi_status_t efi_disk_get_device_name(const efi_handle_t handle, char *buf, int size)
{
        int count;
        int diskid;
        enum uclass_id id;
        unsigned int part;
        struct udevice *dev;
        struct blk_desc *desc;
        const char *if_typename;
        bool is_partition = false;
        struct disk_part *part_data;

        if (!handle || !buf || !size)
                return EFI_INVALID_PARAMETER;

        dev = handle->dev;
        id = device_get_uclass_id(dev);
        if (id == UCLASS_BLK) {
                desc = dev_get_uclass_plat(dev);
        } else if (id == UCLASS_PARTITION) {
                desc = dev_get_uclass_plat(dev_get_parent(dev));
                is_partition = true;
        } else {
                return EFI_INVALID_PARAMETER;
        }
        if_typename = blk_get_uclass_name(desc->uclass_id);
        diskid = desc->devnum;

        if (is_partition) {
                part_data = dev_get_uclass_plat(dev);
                part = part_data->partnum;
                count = snprintf(buf, size, "%s %d:%u", if_typename, diskid,
                                 part);
        } else {
                count = snprintf(buf, size, "%s %d", if_typename, diskid);
        }

        if (count < 0 || (count + 1) > size)
                return EFI_INVALID_PARAMETER;

        return EFI_SUCCESS;
}

/**
 * efi_disks_register() - ensure all block devices are available in UEFI
 *
 * The function probes all block devices. As we store UEFI variables on the
 * EFI system partition this function has to be called before enabling
 * variable services.
 */
efi_status_t efi_disks_register(void)
{
        struct udevice *dev;

        uclass_foreach_dev_probe(UCLASS_BLK, dev) {
        }

        return EFI_SUCCESS;
}