// SPDX-License-Identifier: GPL-2.0+ /* * EFI block driver * * Copyright (c) 2017 Heinrich Schuchardt * * The EFI uclass creates a handle for this driver and installs the * driver binding protocol on it. * * The EFI block driver binds to controllers implementing the block io * protocol. * * When the bind function of the EFI block driver is called it creates a * new U-Boot block device. It installs child handles for all partitions and * installs the simple file protocol on these. * * The read and write functions of the EFI block driver delegate calls to the * controller that it is bound to. * * A usage example is as following: * * U-Boot loads the iPXE snp.efi executable. iPXE connects an iSCSI drive and * exposes a handle with the block IO protocol. It calls ConnectController. * * Now the EFI block driver installs the partitions with the simple file * protocol. * * iPXE uses the simple file protocol to load Grub or the Linux Kernel. */ #include #include #include #include #include #include #include #include /** * struct efi_blk_plat - attributes of a block device * * @handle: handle of the controller on which this driver is installed * @io: block io protocol proxied by this driver */ struct efi_blk_plat { efi_handle_t handle; struct efi_block_io *io; }; /** * efi_bl_read() - read from block device * * @dev: device * @blknr: first block to be read * @blkcnt: number of blocks to read * @buffer: output buffer * Return: number of blocks transferred */ static ulong efi_bl_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, void *buffer) { struct efi_blk_plat *plat = dev_get_plat(dev); struct efi_block_io *io = plat->io; efi_status_t ret; EFI_PRINT("%s: read '%s', from block " LBAFU ", " LBAFU " blocks\n", __func__, dev->name, blknr, blkcnt); ret = EFI_CALL(io->read_blocks( io, io->media->media_id, (u64)blknr, (efi_uintn_t)blkcnt * (efi_uintn_t)io->media->block_size, buffer)); EFI_PRINT("%s: r = %u\n", __func__, (unsigned int)(ret & ~EFI_ERROR_MASK)); if (ret != EFI_SUCCESS) return 0; return blkcnt; } /** * efi_bl_write() - write to block device * * @dev: device * @blknr: first block to be write * @blkcnt: number of blocks to write * @buffer: input buffer * Return: number of blocks transferred */ static ulong efi_bl_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, const void *buffer) { struct efi_blk_plat *plat = dev_get_plat(dev); struct efi_block_io *io = plat->io; efi_status_t ret; EFI_PRINT("%s: write '%s', from block " LBAFU ", " LBAFU " blocks\n", __func__, dev->name, blknr, blkcnt); ret = EFI_CALL(io->write_blocks( io, io->media->media_id, (u64)blknr, (efi_uintn_t)blkcnt * (efi_uintn_t)io->media->block_size, (void *)buffer)); EFI_PRINT("%s: r = %u\n", __func__, (unsigned int)(ret & ~EFI_ERROR_MASK)); if (ret != EFI_SUCCESS) return 0; return blkcnt; } /** * efi_bl_create_block_device() - create a block device for a handle * * @handle: handle * @interface: block io protocol * Return: status code */ static efi_status_t efi_bl_create_block_device(efi_handle_t handle, void *interface) { struct udevice *bdev = NULL, *parent = dm_root(); efi_status_t ret; int devnum; char *name; struct efi_block_io *io = interface; struct efi_blk_plat *plat; devnum = blk_next_free_devnum(UCLASS_EFI_LOADER); if (devnum < 0) return EFI_OUT_OF_RESOURCES; name = calloc(1, 18); /* strlen("efiblk#2147483648") + 1 */ if (!name) return EFI_OUT_OF_RESOURCES; sprintf(name, "efiblk#%d", devnum); /* Create driver model udevice for the EFI block io device */ if (blk_create_device(parent, "efi_blk", name, UCLASS_EFI_LOADER, devnum, io->media->block_size, (lbaint_t)io->media->last_block, &bdev)) { ret = EFI_OUT_OF_RESOURCES; free(name); goto err; } /* Set the DM_FLAG_NAME_ALLOCED flag to avoid a memory leak */ device_set_name_alloced(bdev); plat = dev_get_plat(bdev); plat->handle = handle; plat->io = interface; if (efi_link_dev(handle, bdev)) { ret = EFI_OUT_OF_RESOURCES; goto err; } if (device_probe(bdev)) { ret = EFI_DEVICE_ERROR; goto err; } EFI_PRINT("%s: block device '%s' created\n", __func__, bdev->name); return EFI_SUCCESS; err: efi_unlink_dev(handle); if (bdev) device_unbind(bdev); return ret; } /** * efi_bl_bind() - bind to a block io protocol * * @this: driver binding protocol * @handle: handle * @interface: block io protocol * Return: status code */ static efi_status_t efi_bl_bind( struct efi_driver_binding_extended_protocol *this, efi_handle_t handle, void *interface) { efi_status_t ret = EFI_SUCCESS; struct efi_object *obj = efi_search_obj(handle); EFI_PRINT("%s: handle %p, interface %p\n", __func__, handle, interface); if (!obj || !interface) return EFI_INVALID_PARAMETER; if (!handle->dev) ret = efi_bl_create_block_device(handle, interface); return ret; } /** * efi_bl_init() - initialize block device driver * * @this: extended driver binding protocol */ static efi_status_t efi_bl_init(struct efi_driver_binding_extended_protocol *this) { int ret; ret = event_register("efi_disk add", EVT_DM_POST_PROBE, efi_disk_probe, this); if (ret) { log_err("Event registration for efi_disk add failed\n"); return EFI_OUT_OF_RESOURCES; } ret = event_register("efi_disk del", EVT_DM_PRE_REMOVE, efi_disk_remove, this); if (ret) { log_err("Event registration for efi_disk del failed\n"); return EFI_OUT_OF_RESOURCES; } return EFI_SUCCESS; } /* Block device driver operators */ static const struct blk_ops efi_blk_ops = { .read = efi_bl_read, .write = efi_bl_write, }; /* Identify as block device driver */ U_BOOT_DRIVER(efi_blk) = { .name = "efi_blk", .id = UCLASS_BLK, .ops = &efi_blk_ops, .plat_auto = sizeof(struct efi_blk_plat), }; /* EFI driver operators */ static const struct efi_driver_ops driver_ops = { .protocol = &efi_block_io_guid, .child_protocol = &efi_block_io_guid, .init = efi_bl_init, .bind = efi_bl_bind, }; /* Identify as EFI driver */ U_BOOT_DRIVER(efi_block) = { .name = "EFI block driver", .id = UCLASS_EFI_LOADER, .ops = &driver_ops, };