lib/efi_loader/efi_disk.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  EFI application disk support
   4  *
   5  *  Copyright (c) 2016 Alexander Graf
   6  */
   7
   8 #include <common.h>
   9 #include <blk.h>
  10 #include <dm.h>
  11 #include <efi_loader.h>
  12 #include <part.h>
  13 #include <malloc.h>
  14
  15 const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
  16
  17 /**
  18  * struct efi_disk_obj - EFI disk object
  19  *
  20  * @header:     EFI object header
  21  * @ops:        EFI disk I/O protocol interface
  22  * @ifname:     interface name for block device
  23  * @dev_index:  device index of block device
  24  * @media:      block I/O media information
  25  * @dp:         device path to the block device
  26  * @part:       partition
  27  * @volume:     simple file system protocol of the partition
  28  * @offset:     offset into disk for simple partition
  29  * @desc:       internal block device descriptor
  30  */
  31 struct efi_disk_obj {
  32         struct efi_object header;
  33         struct efi_block_io ops;
  34         const char *ifname;
  35         int dev_index;
  36         struct efi_block_io_media media;
  37         struct efi_device_path *dp;
  38         unsigned int part;
  39         struct efi_simple_file_system_protocol *volume;
  40         lbaint_t offset;
  41         struct blk_desc *desc;
  42 };
  43
  44 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  45                         char extended_verification)
  46 {
  47         EFI_ENTRY("%p, %x", this, extended_verification);
  48         return EFI_EXIT(EFI_DEVICE_ERROR);
  49 }
  50
  51 enum efi_disk_direction {
  52         EFI_DISK_READ,
  53         EFI_DISK_WRITE,
  54 };
  55
  56 static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
  57                         u32 media_id, u64 lba, unsigned long buffer_size,
  58                         void *buffer, enum efi_disk_direction direction)
  59 {
  60         struct efi_disk_obj *diskobj;
  61         struct blk_desc *desc;
  62         int blksz;
  63         int blocks;
  64         unsigned long n;
  65
  66         diskobj = container_of(this, struct efi_disk_obj, ops);
  67         desc = (struct blk_desc *) diskobj->desc;
  68         blksz = desc->blksz;
  69         blocks = buffer_size / blksz;
  70         lba += diskobj->offset;
  71
  72         debug("EFI: %s:%d blocks=%x lba=%llx blksz=%x dir=%d\n", __func__,
  73               __LINE__, blocks, lba, blksz, direction);
  74
  75         /* We only support full block access */
  76         if (buffer_size & (blksz - 1))
  77                 return EFI_DEVICE_ERROR;
  78
  79         if (direction == EFI_DISK_READ)
  80                 n = blk_dread(desc, lba, blocks, buffer);
  81         else
  82                 n = blk_dwrite(desc, lba, blocks, buffer);
  83
  84         /* We don't do interrupts, so check for timers cooperatively */
  85         efi_timer_check();
  86
  87         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
  88
  89         if (n != blocks)
  90                 return EFI_DEVICE_ERROR;
  91
  92         return EFI_SUCCESS;
  93 }
  94
  95 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
  96                         u32 media_id, u64 lba, efi_uintn_t buffer_size,
  97                         void *buffer)
  98 {
  99         void *real_buffer = buffer;
 100         efi_status_t r;
 101
 102 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 103         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 104                 r = efi_disk_read_blocks(this, media_id, lba,
 105                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 106                 if (r != EFI_SUCCESS)
 107                         return r;
 108                 return efi_disk_read_blocks(this, media_id, lba +
 109                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 110                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 111                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 112         }
 113
 114         real_buffer = efi_bounce_buffer;
 115 #endif
 116
 117         EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
 118                   buffer_size, buffer);
 119
 120         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 121                                EFI_DISK_READ);
 122
 123         /* Copy from bounce buffer to real buffer if necessary */
 124         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 125                 memcpy(buffer, real_buffer, buffer_size);
 126
 127         return EFI_EXIT(r);
 128 }
 129
 130 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
 131                         u32 media_id, u64 lba, efi_uintn_t buffer_size,
 132                         void *buffer)
 133 {
 134         void *real_buffer = buffer;
 135         efi_status_t r;
 136
 137 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 138         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 139                 r = efi_disk_write_blocks(this, media_id, lba,
 140                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 141                 if (r != EFI_SUCCESS)
 142                         return r;
 143                 return efi_disk_write_blocks(this, media_id, lba +
 144                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 145                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 146                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 147         }
 148
 149         real_buffer = efi_bounce_buffer;
 150 #endif
 151
 152         EFI_ENTRY("%p, %x, %llx, %zx, %p", this, media_id, lba,
 153                   buffer_size, buffer);
 154
 155         /* Populate bounce buffer if necessary */
 156         if (real_buffer != buffer)
 157                 memcpy(real_buffer, buffer, buffer_size);
 158
 159         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 160                                EFI_DISK_WRITE);
 161
 162         return EFI_EXIT(r);
 163 }
 164
 165 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 166 {
 167         /* We always write synchronously */
 168         EFI_ENTRY("%p", this);
 169         return EFI_EXIT(EFI_SUCCESS);
 170 }
 171
 172 static const struct efi_block_io block_io_disk_template = {
 173         .reset = &efi_disk_reset,
 174         .read_blocks = &efi_disk_read_blocks,
 175         .write_blocks = &efi_disk_write_blocks,
 176         .flush_blocks = &efi_disk_flush_blocks,
 177 };
 178
 179 /*
 180  * Get the simple file system protocol for a file device path.
 181  *
 182  * The full path provided is split into device part and into a file
 183  * part. The device part is used to find the handle on which the
 184  * simple file system protocol is installed.
 185  *
 186  * @full_path   device path including device and file
 187  * @return      simple file system protocol
 188  */
 189 struct efi_simple_file_system_protocol *
 190 efi_fs_from_path(struct efi_device_path *full_path)
 191 {
 192         struct efi_object *efiobj;
 193         struct efi_handler *handler;
 194         struct efi_device_path *device_path;
 195         struct efi_device_path *file_path;
 196         efi_status_t ret;
 197
 198         /* Split the path into a device part and a file part */
 199         ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
 200         if (ret != EFI_SUCCESS)
 201                 return NULL;
 202         efi_free_pool(file_path);
 203
 204         /* Get the EFI object for the partition */
 205         efiobj = efi_dp_find_obj(device_path, NULL);
 206         efi_free_pool(device_path);
 207         if (!efiobj)
 208                 return NULL;
 209
 210         /* Find the simple file system protocol */
 211         ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
 212                                   &handler);
 213         if (ret != EFI_SUCCESS)
 214                 return NULL;
 215
 216         /* Return the simple file system protocol for the partition */
 217         return handler->protocol_interface;
 218 }
 219
 220 /*
 221  * Create a handle for a partition or disk
 222  *
 223  * @parent      parent handle
 224  * @dp_parent   parent device path
 225  * @if_typename interface name for block device
 226  * @desc        internal block device
 227  * @dev_index   device index for block device
 228  * @offset      offset into disk for simple partitions
 229  * @return      disk object
 230  */
 231 static efi_status_t efi_disk_add_dev(
 232                                 efi_handle_t parent,
 233                                 struct efi_device_path *dp_parent,
 234                                 const char *if_typename,
 235                                 struct blk_desc *desc,
 236                                 int dev_index,
 237                                 lbaint_t offset,
 238                                 unsigned int part,
 239                                 struct efi_disk_obj **disk)
 240 {
 241         struct efi_disk_obj *diskobj;
 242         efi_status_t ret;
 243
 244         /* Don't add empty devices */
 245         if (!desc->lba)
 246                 return EFI_NOT_READY;
 247
 248         diskobj = calloc(1, sizeof(*diskobj));
 249         if (!diskobj)
 250                 return EFI_OUT_OF_RESOURCES;
 251
 252         /* Hook up to the device list */
 253         efi_add_handle(&diskobj->header);
 254
 255         /* Fill in object data */
 256         if (part) {
 257                 struct efi_device_path *node = efi_dp_part_node(desc, part);
 258
 259                 diskobj->dp = efi_dp_append_node(dp_parent, node);
 260                 efi_free_pool(node);
 261         } else {
 262                 diskobj->dp = efi_dp_from_part(desc, part);
 263         }
 264         diskobj->part = part;
 265         ret = efi_add_protocol(&diskobj->header, &efi_block_io_guid,
 266                                &diskobj->ops);
 267         if (ret != EFI_SUCCESS)
 268                 return ret;
 269         ret = efi_add_protocol(&diskobj->header, &efi_guid_device_path,
 270                                diskobj->dp);
 271         if (ret != EFI_SUCCESS)
 272                 return ret;
 273         if (part >= 1) {
 274                 diskobj->volume = efi_simple_file_system(desc, part,
 275                                                          diskobj->dp);
 276                 ret = efi_add_protocol(&diskobj->header,
 277                                        &efi_simple_file_system_protocol_guid,
 278                                        diskobj->volume);
 279                 if (ret != EFI_SUCCESS)
 280                         return ret;
 281         }
 282         diskobj->ops = block_io_disk_template;
 283         diskobj->ifname = if_typename;
 284         diskobj->dev_index = dev_index;
 285         diskobj->offset = offset;
 286         diskobj->desc = desc;
 287
 288         /* Fill in EFI IO Media info (for read/write callbacks) */
 289         diskobj->media.removable_media = desc->removable;
 290         diskobj->media.media_present = 1;
 291         diskobj->media.block_size = desc->blksz;
 292         diskobj->media.io_align = desc->blksz;
 293         diskobj->media.last_block = desc->lba - offset;
 294         if (part != 0)
 295                 diskobj->media.logical_partition = 1;
 296         diskobj->ops.media = &diskobj->media;
 297         if (disk)
 298                 *disk = diskobj;
 299         return EFI_SUCCESS;
 300 }
 301
 302 /*
 303  * Create handles and protocols for the partitions of a block device
 304  *
 305  * @parent              handle of the parent disk
 306  * @blk_desc            block device
 307  * @if_typename         interface type
 308  * @diskid              device number
 309  * @pdevname            device name
 310  * @return              number of partitions created
 311  */
 312 int efi_disk_create_partitions(efi_handle_t parent, struct blk_desc *desc,
 313                                const char *if_typename, int diskid,
 314                                const char *pdevname)
 315 {
 316         int disks = 0;
 317         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 318         disk_partition_t info;
 319         int part;
 320         struct efi_device_path *dp = NULL;
 321         efi_status_t ret;
 322         struct efi_handler *handler;
 323
 324         /* Get the device path of the parent */
 325         ret = efi_search_protocol(parent, &efi_guid_device_path, &handler);
 326         if (ret == EFI_SUCCESS)
 327                 dp = handler->protocol_interface;
 328
 329         /* Add devices for each partition */
 330         for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
 331                 if (part_get_info(desc, part, &info))
 332                         continue;
 333                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 334                          part);
 335                 ret = efi_disk_add_dev(parent, dp, if_typename, desc, diskid,
 336                                        info.start, part, NULL);
 337                 if (ret != EFI_SUCCESS) {
 338                         printf("Adding partition %s failed\n", pdevname);
 339                         continue;
 340                 }
 341                 disks++;
 342         }
 343
 344         return disks;
 345 }
 346
 347 /*
 348  * U-Boot doesn't have a list of all online disk devices. So when running our
 349  * EFI payload, we scan through all of the potentially available ones and
 350  * store them in our object pool.
 351  *
 352  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 353  * Consider converting the code to look up devices as needed. The EFI device
 354  * could be a child of the UCLASS_BLK block device, perhaps.
 355  *
 356  * This gets called from do_bootefi_exec().
 357  */
 358 efi_status_t efi_disk_register(void)
 359 {
 360         struct efi_disk_obj *disk;
 361         int disks = 0;
 362         efi_status_t ret;
 363 #ifdef CONFIG_BLK
 364         struct udevice *dev;
 365
 366         for (uclass_first_device_check(UCLASS_BLK, &dev); dev;
 367              uclass_next_device_check(&dev)) {
 368                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 369                 const char *if_typename = blk_get_if_type_name(desc->if_type);
 370
 371                 /* Add block device for the full device */
 372                 printf("Scanning disk %s...\n", dev->name);
 373                 ret = efi_disk_add_dev(NULL, NULL, if_typename,
 374                                         desc, desc->devnum, 0, 0, &disk);
 375                 if (ret == EFI_NOT_READY) {
 376                         printf("Disk %s not ready\n", dev->name);
 377                         continue;
 378                 }
 379                 if (ret) {
 380                         printf("ERROR: failure to add disk device %s, r = %lu\n",
 381                                dev->name, ret & ~EFI_ERROR_MASK);
 382                         return ret;
 383                 }
 384                 disks++;
 385
 386                 /* Partitions show up as block devices in EFI */
 387                 disks += efi_disk_create_partitions(
 388                                         &disk->header, desc, if_typename,
 389                                         desc->devnum, dev->name);
 390         }
 391 #else
 392         int i, if_type;
 393
 394         /* Search for all available disk devices */
 395         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 396                 const struct blk_driver *cur_drvr;
 397                 const char *if_typename;
 398
 399                 cur_drvr = blk_driver_lookup_type(if_type);
 400                 if (!cur_drvr)
 401                         continue;
 402
 403                 if_typename = cur_drvr->if_typename;
 404                 printf("Scanning disks on %s...\n", if_typename);
 405                 for (i = 0; i < 4; i++) {
 406                         struct blk_desc *desc;
 407                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 408
 409                         desc = blk_get_devnum_by_type(if_type, i);
 410                         if (!desc)
 411                                 continue;
 412                         if (desc->type == DEV_TYPE_UNKNOWN)
 413                                 continue;
 414
 415                         snprintf(devname, sizeof(devname), "%s%d",
 416                                  if_typename, i);
 417
 418                         /* Add block device for the full device */
 419                         ret = efi_disk_add_dev(NULL, NULL, if_typename, desc,
 420                                                i, 0, 0, &disk);
 421                         if (ret == EFI_NOT_READY) {
 422                                 printf("Disk %s not ready\n", devname);
 423                                 continue;
 424                         }
 425                         if (ret) {
 426                                 printf("ERROR: failure to add disk device %s, r = %lu\n",
 427                                        devname, ret & ~EFI_ERROR_MASK);
 428                                 return ret;
 429                         }
 430                         disks++;
 431
 432                         /* Partitions show up as block devices in EFI */
 433                         disks += efi_disk_create_partitions
 434                                                 (&disk->header, desc,
 435                                                  if_typename, i, devname);
 436                 }
 437         }
 438 #endif
 439         printf("Found %d disks\n", disks);
 440
 441         return EFI_SUCCESS;
 442 }