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

#include <common.h>
#include <blk.h>
#include <dm.h>
#include <efi_loader.h>
#include <fs.h>
#include <part.h>
#include <malloc.h>

struct efi_system_partition efi_system_partition;

const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;

/**
 * struct efi_disk_obj - EFI disk object
 *
 * @header:     EFI object header
 * @ops:        EFI disk I/O protocol interface
 * @ifname:     interface name for block device
 * @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
 * @offset:     offset into disk for simple partition
 * @desc:       internal block device descriptor
 */
struct efi_disk_obj {
        struct efi_object header;
        struct efi_block_io ops;
        const char *ifname;
        int dev_index;
        struct efi_block_io_media media;
        struct efi_device_path *dp;
        unsigned int part;
        struct efi_simple_file_system_protocol *volume;
        lbaint_t offset;
        struct blk_desc *desc;
};

/**
 * 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);
}

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;
        struct blk_desc *desc;
        int blksz;
        int blocks;
        unsigned long n;

        diskobj = container_of(this, struct efi_disk_obj, ops);
        desc = (struct blk_desc *) diskobj->desc;
        blksz = desc->blksz;
        blocks = buffer_size / blksz;
        lba += diskobj->offset;

        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 (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 */
        if ((uintptr_t)buffer & (this->media->io_align - 1))
                return EFI_INVALID_PARAMETER;
        if (lba * this->media->block_size + buffer_size >
            this->media->last_block * 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 */
        if ((uintptr_t)buffer & (this->media->io_align - 1))
                return EFI_INVALID_PARAMETER;
        if (lba * this->media->block_size + buffer_size >
            this->media->last_block * 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);
        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
 * @if_typename:        interface name for block device
 * @desc:               internal block device
 * @dev_index:          device index for block device
 * @offset:             offset into disk for simple partitions
 * @part:               partition
 * @disk:               pointer to receive the created handle
 * Return:              disk object
 */
static efi_status_t efi_disk_add_dev(
                                efi_handle_t parent,
                                struct efi_device_path *dp_parent,
                                const char *if_typename,
                                struct blk_desc *desc,
                                int dev_index,
                                lbaint_t offset,
                                unsigned int part,
                                struct efi_disk_obj **disk)
{
        struct efi_disk_obj *diskobj;
        struct efi_object *handle;
        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) {
                struct efi_device_path *node = efi_dp_part_node(desc, part);

                diskobj->dp = efi_dp_append_node(dp_parent, node);
                efi_free_pool(node);
        } else {
                diskobj->dp = efi_dp_from_part(desc, part);
        }
        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_CALL(efi_install_multiple_protocol_interfaces(
                        &handle, &efi_guid_device_path, diskobj->dp,
                        &efi_block_io_guid, &diskobj->ops, NULL));
        if (ret != EFI_SUCCESS)
                return ret;

        /*
         * 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)
                        return ret;
        }
        diskobj->ops = block_io_disk_template;
        diskobj->ifname = if_typename;
        diskobj->dev_index = dev_index;
        diskobj->offset = offset;
        diskobj->desc = desc;

        /* 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;
        diskobj->media.last_block = desc->lba - offset;
        if (part)
                diskobj->media.logical_partition = 1;
        diskobj->ops.media = &diskobj->media;
        if (disk)
                *disk = diskobj;

        /* Store first EFI system partition */
        if (part && !efi_system_partition.if_type) {
                int r;
                struct disk_partition info;

                r = part_get_info(desc, part, &info);
                if (r)
                        return EFI_DEVICE_ERROR;
                if (info.bootable & PART_EFI_SYSTEM_PARTITION) {
                        efi_system_partition.if_type = desc->if_type;
                        efi_system_partition.devnum = desc->devnum;
                        efi_system_partition.part = part;
                        EFI_PRINT("EFI system partition: %s %d:%d\n",
                                  blk_get_if_type_name(desc->if_type),
                                  desc->devnum, part);
                }
        }
        return EFI_SUCCESS;
}

/**
 * efi_disk_create_partitions() - create handles and protocols for partitions
 *
 * Create handles and protocols for the partitions of a block device.
 *
 * @parent:             handle of the parent disk
 * @desc:               block device
 * @if_typename:        interface type
 * @diskid:             device number
 * @pdevname:           device name
 * Return:              number of partitions created
 */
int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
                               const char *if_typename, int diskid,
                               const char *pdevname)
{
        int disks = 0;
        char devname[32] = { 0 }; /* dp->str is u16[32] long */
        struct disk_partition info;
        int part;
        struct efi_device_path *dp = NULL;
        efi_status_t ret;
        struct efi_handler *handler;

        /* Get the device path of the parent */
        ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
        if (ret == EFI_SUCCESS)
                dp = handler->protocol_interface;

        /* Add devices for each partition */
        for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
                if (part_get_info(desc, part, &info))
                        continue;
                snprintf(devname, sizeof(devname), "%s:%d", pdevname,
                         part);
                ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
                                       info.start, part, NULL);
                if (ret != EFI_SUCCESS) {
                        printf("Adding partition %s failed\n", pdevname);
                        continue;
                }
                disks++;
        }

        return disks;
}

/**
 * efi_disk_register() - register block devices
 *
 * U-Boot doesn't have a list of all online disk devices. So when running our
 * EFI payload, we scan through all of the potentially available ones and
 * store them in our object pool.
 *
 * This function is called in efi_init_obj_list().
 *
 * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 * Consider converting the code to look up devices as needed. The EFI device
 * could be a child of the UCLASS_BLK block device, perhaps.
 *
 * Return:      status code
 */
efi_status_t efi_disk_register(void)
{
        struct efi_disk_obj *disk;
        int disks = 0;
        efi_status_t ret;
#ifdef CONFIG_BLK
        struct udevice *dev;

        for (uclass_first_device_check(UCLASS_BLK, &dev); dev;
             uclass_next_device_check(&dev)) {
                struct blk_desc *desc = dev_get_uclass_platdata(dev);
                const char *if_typename = blk_get_if_type_name(desc->if_type);

                /* Add block device for the full device */
                printf("Scanning disk %s...\n", dev->name);
                ret = efi_disk_add_dev(NULL, NULL, if_typename,
                                        desc, desc->devnum, 0, 0, &disk);
                if (ret == EFI_NOT_READY) {
                        printf("Disk %s not ready\n", dev->name);
                        continue;
                }
                if (ret) {
                        printf("ERROR: failure to add disk device %s, r = %lu\n",
                               dev->name, ret & ~EFI_ERROR_MASK);
                        return ret;
                }
                disks++;

                /* Partitions show up as block devices in EFI */
                disks += efi_disk_create_partitions(
                                        &disk->header, desc, if_typename,
                                        desc->devnum, dev->name);
        }
#else
        int i, if_type;

        /* Search for all available disk devices */
        for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
                const struct blk_driver *cur_drvr;
                const char *if_typename;

                cur_drvr = blk_driver_lookup_type(if_type);
                if (!cur_drvr)
                        continue;

                if_typename = cur_drvr->if_typename;
                printf("Scanning disks on %s...\n", if_typename);
                for (i = 0; i < 4; i++) {
                        struct blk_desc *desc;
                        char devname[32] = { 0 }; /* dp->str is u16[32] long */

                        desc = blk_get_devnum_by_type(if_type, i);
                        if (!desc)
                                continue;
                        if (desc->type == DEV_TYPE_UNKNOWN)
                                continue;

                        snprintf(devname, sizeof(devname), "%s%d",
                                 if_typename, i);

                        /* Add block device for the full device */
                        ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
                                               i, 0, 0, &disk);
                        if (ret == EFI_NOT_READY) {
                                printf("Disk %s not ready\n", devname);
                                continue;
                        }
                        if (ret) {
                                printf("ERROR: failure to add disk device %s, r = %lu\n",
                                       devname, ret & ~EFI_ERROR_MASK);
                                return ret;
                        }
                        disks++;

                        /* Partitions show up as block devices in EFI */
                        disks += efi_disk_create_partitions
                                                (&disk->header, desc,
                                                 if_typename, i, devname);
                }
        }
#endif
        printf("Found %d disks\n", disks);

        return EFI_SUCCESS;
}

/**
 * efi_disk_is_system_part() - check if handle refers to an EFI system partition
 *
 * @handle:     handle of partition
 *
 * Return:      true if handle refers to an EFI system partition
 */
bool efi_disk_is_system_part(efi_handle_t handle)
{
        struct efi_handler *handler;
        struct efi_disk_obj *diskobj;
        struct disk_partition info;
        efi_status_t ret;
        int r;

        /* check if this is a block device */
        ret = efi_search_protocol(handle, &efi_block_io_guid, &handler);
        if (ret != EFI_SUCCESS)
                return false;

        diskobj = container_of(handle, struct efi_disk_obj, header);

        r = part_get_info(diskobj->desc, diskobj->part, &info);
        if (r)
                return false;

        return !!(info.bootable & PART_EFI_SYSTEM_PARTITION);
}