Tom Rini | 70df9d6 | 2018-05-07 17:02:21 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Heinrich Schuchardt | 11206f4 | 2018-01-21 19:29:30 +0100 | [diff] [blame] | 2 | /* |
| 3 | * EFI block driver |
| 4 | * |
| 5 | * Copyright (c) 2017 Heinrich Schuchardt |
| 6 | * |
Heinrich Schuchardt | 11206f4 | 2018-01-21 19:29:30 +0100 | [diff] [blame] | 7 | * The EFI uclass creates a handle for this driver and installs the |
| 8 | * driver binding protocol on it. |
| 9 | * |
| 10 | * The EFI block driver binds to controllers implementing the block io |
| 11 | * protocol. |
| 12 | * |
| 13 | * When the bind function of the EFI block driver is called it creates a |
| 14 | * new U-Boot block device. It installs child handles for all partitions and |
| 15 | * installs the simple file protocol on these. |
| 16 | * |
| 17 | * The read and write functions of the EFI block driver delegate calls to the |
| 18 | * controller that it is bound to. |
| 19 | * |
| 20 | * A usage example is as following: |
| 21 | * |
| 22 | * U-Boot loads the iPXE snp.efi executable. iPXE connects an iSCSI drive and |
| 23 | * exposes a handle with the block IO protocol. It calls ConnectController. |
| 24 | * |
| 25 | * Now the EFI block driver installs the partitions with the simple file |
| 26 | * protocol. |
| 27 | * |
| 28 | * iPXE uses the simple file protocol to load Grub or the Linux Kernel. |
| 29 | */ |
| 30 | |
| 31 | #include <efi_driver.h> |
| 32 | #include <dm/device-internal.h> |
| 33 | #include <dm/root.h> |
| 34 | |
| 35 | /* |
| 36 | * EFI attributes of the udevice handled by this driver. |
| 37 | * |
| 38 | * handle handle of the controller on which this driver is installed |
| 39 | * io block io protocol proxied by this driver |
| 40 | */ |
| 41 | struct efi_blk_priv { |
| 42 | efi_handle_t handle; |
| 43 | struct efi_block_io *io; |
| 44 | }; |
| 45 | |
| 46 | /* |
| 47 | * Read from block device |
| 48 | * |
| 49 | * @dev device |
| 50 | * @blknr first block to be read |
| 51 | * @blkcnt number of blocks to read |
| 52 | * @buffer output buffer |
| 53 | * @return number of blocks transferred |
| 54 | */ |
| 55 | static ulong efi_bl_read(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, |
| 56 | void *buffer) |
| 57 | { |
| 58 | struct efi_blk_priv *priv = dev->priv; |
| 59 | struct efi_block_io *io = priv->io; |
| 60 | efi_status_t ret; |
| 61 | |
| 62 | EFI_PRINT("%s: read '%s', from block " LBAFU ", " LBAFU " blocks\n", |
| 63 | __func__, dev->name, blknr, blkcnt); |
| 64 | ret = EFI_CALL(io->read_blocks( |
| 65 | io, io->media->media_id, (u64)blknr, |
| 66 | (efi_uintn_t)blkcnt * |
| 67 | (efi_uintn_t)io->media->block_size, buffer)); |
| 68 | EFI_PRINT("%s: r = %u\n", __func__, |
| 69 | (unsigned int)(ret & ~EFI_ERROR_MASK)); |
| 70 | if (ret != EFI_SUCCESS) |
| 71 | return 0; |
| 72 | return blkcnt; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * Write to block device |
| 77 | * |
| 78 | * @dev device |
| 79 | * @blknr first block to be write |
| 80 | * @blkcnt number of blocks to write |
| 81 | * @buffer input buffer |
| 82 | * @return number of blocks transferred |
| 83 | */ |
| 84 | static ulong efi_bl_write(struct udevice *dev, lbaint_t blknr, lbaint_t blkcnt, |
| 85 | const void *buffer) |
| 86 | { |
| 87 | struct efi_blk_priv *priv = dev->priv; |
| 88 | struct efi_block_io *io = priv->io; |
| 89 | efi_status_t ret; |
| 90 | |
| 91 | EFI_PRINT("%s: write '%s', from block " LBAFU ", " LBAFU " blocks\n", |
| 92 | __func__, dev->name, blknr, blkcnt); |
| 93 | ret = EFI_CALL(io->write_blocks( |
| 94 | io, io->media->media_id, (u64)blknr, |
| 95 | (efi_uintn_t)blkcnt * |
| 96 | (efi_uintn_t)io->media->block_size, |
| 97 | (void *)buffer)); |
| 98 | EFI_PRINT("%s: r = %u\n", __func__, |
| 99 | (unsigned int)(ret & ~EFI_ERROR_MASK)); |
| 100 | if (ret != EFI_SUCCESS) |
| 101 | return 0; |
| 102 | return blkcnt; |
| 103 | } |
| 104 | |
| 105 | /* |
| 106 | * Create partions for the block device. |
| 107 | * |
| 108 | * @handle EFI handle of the block device |
| 109 | * @dev udevice of the block device |
| 110 | */ |
| 111 | static int efi_bl_bind_partitions(efi_handle_t handle, struct udevice *dev) |
| 112 | { |
| 113 | struct blk_desc *desc; |
| 114 | const char *if_typename; |
| 115 | |
| 116 | desc = dev_get_uclass_platdata(dev); |
| 117 | if_typename = blk_get_if_type_name(desc->if_type); |
| 118 | |
| 119 | return efi_disk_create_partitions(handle, desc, if_typename, |
| 120 | desc->devnum, dev->name); |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * Create a block device for a handle |
| 125 | * |
| 126 | * @handle handle |
| 127 | * @interface block io protocol |
| 128 | * @return 0 = success |
| 129 | */ |
| 130 | static int efi_bl_bind(efi_handle_t handle, void *interface) |
| 131 | { |
| 132 | struct udevice *bdev, *parent = dm_root(); |
| 133 | int ret, devnum; |
| 134 | char *name; |
| 135 | struct efi_object *obj = efi_search_obj(handle); |
| 136 | struct efi_block_io *io = interface; |
| 137 | int disks; |
| 138 | struct efi_blk_priv *priv; |
| 139 | |
| 140 | EFI_PRINT("%s: handle %p, interface %p\n", __func__, handle, io); |
| 141 | |
| 142 | if (!obj) |
| 143 | return -ENOENT; |
| 144 | |
| 145 | devnum = blk_find_max_devnum(IF_TYPE_EFI); |
| 146 | if (devnum == -ENODEV) |
| 147 | devnum = 0; |
| 148 | else if (devnum < 0) |
| 149 | return devnum; |
| 150 | |
| 151 | name = calloc(1, 18); /* strlen("efiblk#2147483648") + 1 */ |
| 152 | if (!name) |
| 153 | return -ENOMEM; |
| 154 | sprintf(name, "efiblk#%d", devnum); |
| 155 | |
| 156 | /* Create driver model udevice for the EFI block io device */ |
| 157 | ret = blk_create_device(parent, "efi_blk", name, IF_TYPE_EFI, devnum, |
| 158 | io->media->block_size, |
| 159 | (lbaint_t)io->media->last_block, &bdev); |
| 160 | if (ret) |
| 161 | return ret; |
| 162 | if (!bdev) |
| 163 | return -ENOENT; |
| 164 | /* Allocate priv */ |
| 165 | ret = device_probe(bdev); |
| 166 | if (ret) |
| 167 | return ret; |
| 168 | EFI_PRINT("%s: block device '%s' created\n", __func__, bdev->name); |
| 169 | |
| 170 | priv = bdev->priv; |
| 171 | priv->handle = handle; |
| 172 | priv->io = interface; |
| 173 | |
| 174 | ret = blk_prepare_device(bdev); |
| 175 | |
| 176 | /* Create handles for the partions of the block device */ |
| 177 | disks = efi_bl_bind_partitions(handle, bdev); |
| 178 | EFI_PRINT("Found %d partitions\n", disks); |
| 179 | |
| 180 | return 0; |
| 181 | } |
| 182 | |
| 183 | /* Block device driver operators */ |
| 184 | static const struct blk_ops efi_blk_ops = { |
| 185 | .read = efi_bl_read, |
| 186 | .write = efi_bl_write, |
| 187 | }; |
| 188 | |
| 189 | /* Identify as block device driver */ |
| 190 | U_BOOT_DRIVER(efi_blk) = { |
| 191 | .name = "efi_blk", |
| 192 | .id = UCLASS_BLK, |
| 193 | .ops = &efi_blk_ops, |
| 194 | .priv_auto_alloc_size = sizeof(struct efi_blk_priv), |
| 195 | }; |
| 196 | |
| 197 | /* EFI driver operators */ |
| 198 | static const struct efi_driver_ops driver_ops = { |
| 199 | .protocol = &efi_block_io_guid, |
| 200 | .child_protocol = &efi_block_io_guid, |
| 201 | .bind = efi_bl_bind, |
| 202 | }; |
| 203 | |
| 204 | /* Identify as EFI driver */ |
| 205 | U_BOOT_DRIVER(efi_block) = { |
| 206 | .name = "EFI block driver", |
| 207 | .id = UCLASS_EFI, |
| 208 | .ops = &driver_ops, |
| 209 | }; |