lib/efi_loader/efi_disk.c

   1 /*
   2  *  EFI application disk support
   3  *
   4  *  Copyright (c) 2016 Alexander Graf
   5  *
   6  *  SPDX-License-Identifier:     GPL-2.0+
   7  */
   8
   9 #include <common.h>
  10 #include <blk.h>
  11 #include <efi_loader.h>
  12 #include <inttypes.h>
  13 #include <part.h>
  14 #include <malloc.h>
  15
  16 static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
  17
  18 struct efi_disk_obj {
  19         /* Generic EFI object parent class data */
  20         struct efi_object parent;
  21         /* EFI Interface callback struct for block I/O */
  22         struct efi_block_io ops;
  23         /* U-Boot ifname for block device */
  24         const char *ifname;
  25         /* U-Boot dev_index for block device */
  26         int dev_index;
  27         /* EFI Interface Media descriptor struct, referenced by ops */
  28         struct efi_block_io_media media;
  29         /* EFI device path to this block device */
  30         struct efi_device_path_file_path *dp;
  31         /* Offset into disk for simple partitions */
  32         lbaint_t offset;
  33 };
  34
  35 static efi_status_t efi_disk_open_block(void *handle, efi_guid_t *protocol,
  36                         void **protocol_interface, void *agent_handle,
  37                         void *controller_handle, uint32_t attributes)
  38 {
  39         struct efi_disk_obj *diskobj = handle;
  40
  41         *protocol_interface = &diskobj->ops;
  42
  43         return EFI_SUCCESS;
  44 }
  45
  46 static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
  47                         void **protocol_interface, void *agent_handle,
  48                         void *controller_handle, uint32_t attributes)
  49 {
  50         struct efi_disk_obj *diskobj = handle;
  51
  52         *protocol_interface = diskobj->dp;
  53
  54         return EFI_SUCCESS;
  55 }
  56
  57 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  58                         char extended_verification)
  59 {
  60         EFI_ENTRY("%p, %x", this, extended_verification);
  61         return EFI_EXIT(EFI_DEVICE_ERROR);
  62 }
  63
  64 enum efi_disk_direction {
  65         EFI_DISK_READ,
  66         EFI_DISK_WRITE,
  67 };
  68
  69 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
  70                         u32 media_id, u64 lba, unsigned long buffer_size,
  71                         void *buffer, enum efi_disk_direction direction)
  72 {
  73         struct efi_disk_obj *diskobj;
  74         struct blk_desc *desc;
  75         int blksz;
  76         int blocks;
  77         unsigned long n;
  78
  79         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
  80                   buffer_size, buffer);
  81
  82         diskobj = container_of(this, struct efi_disk_obj, ops);
  83         if (!(desc = blk_get_dev(diskobj->ifname, diskobj->dev_index)))
  84                 return EFI_EXIT(EFI_DEVICE_ERROR);
  85         blksz = desc->blksz;
  86         blocks = buffer_size / blksz;
  87         lba += diskobj->offset;
  88
  89 #ifdef DEBUG_EFI
  90         printf("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  91                __LINE__, blocks, lba, blksz, direction);
  92 #endif
  93
  94         /* We only support full block access */
  95         if (buffer_size & (blksz - 1))
  96                 return EFI_EXIT(EFI_DEVICE_ERROR);
  97
  98         if (direction == EFI_DISK_READ)
  99                 n = desc->block_read(desc, lba, blocks, buffer);
 100         else
 101                 n = desc->block_write(desc, lba, blocks, buffer);
 102
 103         /* We don't do interrupts, so check for timers cooperatively */
 104         efi_timer_check();
 105
 106 #ifdef DEBUG_EFI
 107         printf("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
 108 #endif
 109         if (n != blocks)
 110                 return EFI_EXIT(EFI_DEVICE_ERROR);
 111
 112         return EFI_EXIT(EFI_SUCCESS);
 113 }
 114
 115 static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
 116                         u32 media_id, u64 lba, unsigned long buffer_size,
 117                         void *buffer)
 118 {
 119         return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
 120                                   EFI_DISK_READ);
 121 }
 122
 123 static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
 124                         u32 media_id, u64 lba, unsigned long buffer_size,
 125                         void *buffer)
 126 {
 127         return efi_disk_rw_blocks(this, media_id, lba, buffer_size, buffer,
 128                                   EFI_DISK_WRITE);
 129 }
 130
 131 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 132 {
 133         /* We always write synchronously */
 134         EFI_ENTRY("%p", this);
 135         return EFI_EXIT(EFI_SUCCESS);
 136 }
 137
 138 static const struct efi_block_io block_io_disk_template = {
 139         .reset = &efi_disk_reset,
 140         .read_blocks = &efi_disk_read_blocks,
 141         .write_blocks = &efi_disk_write_blocks,
 142         .flush_blocks = &efi_disk_flush_blocks,
 143 };
 144
 145 static void efi_disk_add_dev(char *name,
 146                              const struct blk_driver *cur_drvr,
 147                              const struct blk_desc *desc,
 148                              int dev_index,
 149                              lbaint_t offset)
 150 {
 151         struct efi_disk_obj *diskobj;
 152         struct efi_device_path_file_path *dp;
 153         int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
 154
 155         diskobj = calloc(1, objlen);
 156
 157         /* Fill in object data */
 158         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 159         diskobj->parent.protocols[0].open = efi_disk_open_block;
 160         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 161         diskobj->parent.protocols[1].open = efi_disk_open_dp;
 162         diskobj->parent.handle = diskobj;
 163         diskobj->ops = block_io_disk_template;
 164         diskobj->ifname = cur_drvr->if_typename;
 165         diskobj->dev_index = dev_index;
 166         diskobj->offset = offset;
 167
 168         /* Fill in EFI IO Media info (for read/write callbacks) */
 169         diskobj->media.removable_media = desc->removable;
 170         diskobj->media.media_present = 1;
 171         diskobj->media.block_size = desc->blksz;
 172         diskobj->media.io_align = desc->blksz;
 173         diskobj->media.last_block = desc->lba;
 174         diskobj->ops.media = &diskobj->media;
 175
 176         /* Fill in device path */
 177         dp = (void*)&diskobj[1];
 178         diskobj->dp = dp;
 179         dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 180         dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 181         dp[0].dp.length = sizeof(*dp);
 182         ascii2unicode(dp[0].str, name);
 183
 184         dp[1].dp.type = DEVICE_PATH_TYPE_END;
 185         dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
 186         dp[1].dp.length = sizeof(*dp);
 187
 188         /* Hook up to the device list */
 189         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 190 }
 191
 192 static int efi_disk_create_eltorito(struct blk_desc *desc,
 193                                     const struct blk_driver *cur_drvr,
 194                                     int diskid)
 195 {
 196         int disks = 0;
 197 #ifdef CONFIG_ISO_PARTITION
 198         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 199         disk_partition_t info;
 200         int part = 1;
 201
 202         if (desc->part_type != PART_TYPE_ISO)
 203                 return 0;
 204
 205         while (!part_get_info(desc, part, &info)) {
 206                 snprintf(devname, sizeof(devname), "%s%d:%d",
 207                          cur_drvr->if_typename, diskid, part);
 208                 efi_disk_add_dev(devname, cur_drvr, desc, diskid, info.start);
 209                 part++;
 210                 disks++;
 211         }
 212 #endif
 213
 214         return disks;
 215 }
 216
 217 /*
 218  * U-Boot doesn't have a list of all online disk devices. So when running our
 219  * EFI payload, we scan through all of the potentially available ones and
 220  * store them in our object pool.
 221  *
 222  * This gets called from do_bootefi_exec().
 223  */
 224 int efi_disk_register(void)
 225 {
 226         const struct blk_driver *cur_drvr;
 227         int i, if_type;
 228         int disks = 0;
 229
 230         /* Search for all available disk devices */
 231         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 232                 cur_drvr = blk_driver_lookup_type(if_type);
 233                 if (!cur_drvr)
 234                         continue;
 235
 236                 printf("Scanning disks on %s...\n", cur_drvr->if_typename);
 237                 for (i = 0; i < 4; i++) {
 238                         struct blk_desc *desc;
 239                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 240
 241                         desc = blk_get_devnum_by_type(if_type, i);
 242                         if (!desc)
 243                                 continue;
 244                         if (desc->type == DEV_TYPE_UNKNOWN)
 245                                 continue;
 246
 247                         snprintf(devname, sizeof(devname), "%s%d",
 248                                  cur_drvr->if_typename, i);
 249                         efi_disk_add_dev(devname, cur_drvr, desc, i, 0);
 250                         disks++;
 251
 252                         /*
 253                          * El Torito images show up as block devices
 254                          * in an EFI world, so let's create them here
 255                          */
 256                         disks += efi_disk_create_eltorito(desc, cur_drvr, i);
 257                 }
 258         }
 259         printf("Found %d disks\n", disks);
 260
 261         return 0;
 262 }