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