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 <dm.h>
  12 #include <efi_loader.h>
  13 #include <inttypes.h>
  14 #include <part.h>
  15 #include <malloc.h>
  16
  17 static const efi_guid_t efi_block_io_guid = BLOCK_IO_GUID;
  18
  19 struct efi_disk_obj {
  20         /* Generic EFI object parent class data */
  21         struct efi_object parent;
  22         /* EFI Interface callback struct for block I/O */
  23         struct efi_block_io ops;
  24         /* U-Boot ifname for block device */
  25         const char *ifname;
  26         /* U-Boot dev_index for block device */
  27         int dev_index;
  28         /* EFI Interface Media descriptor struct, referenced by ops */
  29         struct efi_block_io_media media;
  30         /* EFI device path to this block device */
  31         struct efi_device_path *dp;
  32         /* partition # */
  33         unsigned int part;
  34         /* handle to filesys proto (for partition objects) */
  35         struct efi_simple_file_system_protocol *volume;
  36         /* Offset into disk for simple partitions */
  37         lbaint_t offset;
  38         /* Internal block device */
  39         struct blk_desc *desc;
  40 };
  41
  42 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  43                         char extended_verification)
  44 {
  45         EFI_ENTRY("%p, %x", this, extended_verification);
  46         return EFI_EXIT(EFI_DEVICE_ERROR);
  47 }
  48
  49 enum efi_disk_direction {
  50         EFI_DISK_READ,
  51         EFI_DISK_WRITE,
  52 };
  53
  54 static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
  55                         u32 media_id, u64 lba, unsigned long buffer_size,
  56                         void *buffer, enum efi_disk_direction direction)
  57 {
  58         struct efi_disk_obj *diskobj;
  59         struct blk_desc *desc;
  60         int blksz;
  61         int blocks;
  62         unsigned long n;
  63
  64         diskobj = container_of(this, struct efi_disk_obj, ops);
  65         desc = (struct blk_desc *) diskobj->desc;
  66         blksz = desc->blksz;
  67         blocks = buffer_size / blksz;
  68         lba += diskobj->offset;
  69
  70         debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  71               __LINE__, blocks, lba, blksz, direction);
  72
  73         /* We only support full block access */
  74         if (buffer_size & (blksz - 1))
  75                 return EFI_DEVICE_ERROR;
  76
  77         if (direction == EFI_DISK_READ)
  78                 n = blk_dread(desc, lba, blocks, buffer);
  79         else
  80                 n = blk_dwrite(desc, lba, blocks, buffer);
  81
  82         /* We don't do interrupts, so check for timers cooperatively */
  83         efi_timer_check();
  84
  85         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
  86
  87         if (n != blocks)
  88                 return EFI_DEVICE_ERROR;
  89
  90         return EFI_SUCCESS;
  91 }
  92
  93 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
  94                         u32 media_id, u64 lba, unsigned long buffer_size,
  95                         void *buffer)
  96 {
  97         void *real_buffer = buffer;
  98         efi_status_t r;
  99
 100 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 101         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 102                 r = efi_disk_read_blocks(this, media_id, lba,
 103                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 104                 if (r != EFI_SUCCESS)
 105                         return r;
 106                 return efi_disk_read_blocks(this, media_id, lba +
 107                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 108                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 109                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 110         }
 111
 112         real_buffer = efi_bounce_buffer;
 113 #endif
 114
 115         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 116                   buffer_size, buffer);
 117
 118         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 119                                EFI_DISK_READ);
 120
 121         /* Copy from bounce buffer to real buffer if necessary */
 122         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 123                 memcpy(buffer, real_buffer, buffer_size);
 124
 125         return EFI_EXIT(r);
 126 }
 127
 128 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
 129                         u32 media_id, u64 lba, unsigned long buffer_size,
 130                         void *buffer)
 131 {
 132         void *real_buffer = buffer;
 133         efi_status_t r;
 134
 135 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 136         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 137                 r = efi_disk_write_blocks(this, media_id, lba,
 138                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 139                 if (r != EFI_SUCCESS)
 140                         return r;
 141                 return efi_disk_write_blocks(this, media_id, lba +
 142                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 143                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 144                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 145         }
 146
 147         real_buffer = efi_bounce_buffer;
 148 #endif
 149
 150         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 151                   buffer_size, buffer);
 152
 153         /* Populate bounce buffer if necessary */
 154         if (real_buffer != buffer)
 155                 memcpy(real_buffer, buffer, buffer_size);
 156
 157         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 158                                EFI_DISK_WRITE);
 159
 160         return EFI_EXIT(r);
 161 }
 162
 163 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 164 {
 165         /* We always write synchronously */
 166         EFI_ENTRY("%p", this);
 167         return EFI_EXIT(EFI_SUCCESS);
 168 }
 169
 170 static const struct efi_block_io block_io_disk_template = {
 171         .reset = &efi_disk_reset,
 172         .read_blocks = &efi_disk_read_blocks,
 173         .write_blocks = &efi_disk_write_blocks,
 174         .flush_blocks = &efi_disk_flush_blocks,
 175 };
 176
 177 /*
 178  * Find filesystem from a device-path.  The passed in path 'p' probably
 179  * contains one or more /File(name) nodes, so the comparison stops at
 180  * the first /File() node, and returns the pointer to that via 'rp'.
 181  * This is mostly intended to be a helper to map a device-path to an
 182  * efi_file_handle object.
 183  */
 184 struct efi_simple_file_system_protocol *
 185 efi_fs_from_path(struct efi_device_path *fp)
 186 {
 187         struct efi_object *efiobj;
 188         struct efi_disk_obj *diskobj;
 189
 190         efiobj = efi_dp_find_obj(fp, NULL);
 191         if (!efiobj)
 192                 return NULL;
 193
 194         diskobj = container_of(efiobj, struct efi_disk_obj, parent);
 195
 196         return diskobj->volume;
 197 }
 198
 199 /*
 200  * Create a device for a disk
 201  *
 202  * @name        not used
 203  * @if_typename interface name for block device
 204  * @desc        internal block device
 205  * @dev_index   device index for block device
 206  * @offset      offset into disk for simple partitions
 207  */
 208 static void efi_disk_add_dev(const char *name,
 209                              const char *if_typename,
 210                              struct blk_desc *desc,
 211                              int dev_index,
 212                              lbaint_t offset,
 213                              unsigned int part)
 214 {
 215         struct efi_disk_obj *diskobj;
 216         efi_status_t ret;
 217
 218         /* Don't add empty devices */
 219         if (!desc->lba)
 220                 return;
 221
 222         diskobj = calloc(1, sizeof(*diskobj));
 223         if (!diskobj)
 224                 goto out_of_memory;
 225
 226         /* Hook up to the device list */
 227         INIT_LIST_HEAD(&diskobj->parent.protocols);
 228         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 229
 230         /* Fill in object data */
 231         diskobj->dp = efi_dp_from_part(desc, part);
 232         diskobj->part = part;
 233         diskobj->parent.handle = diskobj;
 234         ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
 235                                &diskobj->ops);
 236         if (ret != EFI_SUCCESS)
 237                 goto out_of_memory;
 238         ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
 239                                diskobj->dp);
 240         if (ret != EFI_SUCCESS)
 241                 goto out_of_memory;
 242         if (part >= 1) {
 243                 diskobj->volume = efi_simple_file_system(desc, part,
 244                                                          diskobj->dp);
 245                 ret = efi_add_protocol(diskobj->parent.handle,
 246                                        &efi_simple_file_system_protocol_guid,
 247                                        &diskobj->volume);
 248                 if (ret != EFI_SUCCESS)
 249                         goto out_of_memory;
 250         }
 251         diskobj->ops = block_io_disk_template;
 252         diskobj->ifname = if_typename;
 253         diskobj->dev_index = dev_index;
 254         diskobj->offset = offset;
 255         diskobj->desc = desc;
 256
 257         /* Fill in EFI IO Media info (for read/write callbacks) */
 258         diskobj->media.removable_media = desc->removable;
 259         diskobj->media.media_present = 1;
 260         diskobj->media.block_size = desc->blksz;
 261         diskobj->media.io_align = desc->blksz;
 262         diskobj->media.last_block = desc->lba - offset;
 263         diskobj->ops.media = &diskobj->media;
 264         return;
 265 out_of_memory:
 266         printf("ERROR: Out of memory\n");
 267 }
 268
 269 static int efi_disk_create_eltorito(struct blk_desc *desc,
 270                                     const char *if_typename,
 271                                     int diskid,
 272                                     const char *pdevname)
 273 {
 274         int disks = 0;
 275 #if CONFIG_IS_ENABLED(ISO_PARTITION)
 276         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 277         disk_partition_t info;
 278         int part;
 279
 280         if (desc->part_type != PART_TYPE_ISO)
 281                 return 0;
 282
 283         /* and devices for each partition: */
 284         for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
 285                 if (part_get_info(desc, part, &info))
 286                         continue;
 287                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 288                          part);
 289                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 290                                  info.start, part);
 291                 disks++;
 292         }
 293
 294         /* ... and add block device: */
 295         efi_disk_add_dev(devname, if_typename, desc, diskid, 0, 0);
 296 #endif
 297
 298         return disks;
 299 }
 300
 301 /*
 302  * U-Boot doesn't have a list of all online disk devices. So when running our
 303  * EFI payload, we scan through all of the potentially available ones and
 304  * store them in our object pool.
 305  *
 306  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 307  * Consider converting the code to look up devices as needed. The EFI device
 308  * could be a child of the UCLASS_BLK block device, perhaps.
 309  *
 310  * This gets called from do_bootefi_exec().
 311  */
 312 int efi_disk_register(void)
 313 {
 314         int disks = 0;
 315 #ifdef CONFIG_BLK
 316         struct udevice *dev;
 317
 318         for (uclass_first_device_check(UCLASS_BLK, &dev);
 319              dev;
 320              uclass_next_device_check(&dev)) {
 321                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 322                 const char *if_typename = dev->driver->name;
 323                 disk_partition_t info;
 324                 int part;
 325
 326                 printf("Scanning disk %s...\n", dev->name);
 327
 328                 /* add devices for each partition: */
 329                 for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
 330                         if (part_get_info(desc, part, &info))
 331                                 continue;
 332                         efi_disk_add_dev(dev->name, if_typename, desc,
 333                                          desc->devnum, 0, part);
 334                 }
 335
 336                 /* ... and add block device: */
 337                 efi_disk_add_dev(dev->name, if_typename, desc,
 338                                  desc->devnum, 0, 0);
 339
 340                 disks++;
 341
 342                 /*
 343                 * El Torito images show up as block devices in an EFI world,
 344                 * so let's create them here
 345                 */
 346                 disks += efi_disk_create_eltorito(desc, if_typename,
 347                                                   desc->devnum, dev->name);
 348         }
 349 #else
 350         int i, if_type;
 351
 352         /* Search for all available disk devices */
 353         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 354                 const struct blk_driver *cur_drvr;
 355                 const char *if_typename;
 356
 357                 cur_drvr = blk_driver_lookup_type(if_type);
 358                 if (!cur_drvr)
 359                         continue;
 360
 361                 if_typename = cur_drvr->if_typename;
 362                 printf("Scanning disks on %s...\n", if_typename);
 363                 for (i = 0; i < 4; i++) {
 364                         struct blk_desc *desc;
 365                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 366                         disk_partition_t info;
 367                         int part;
 368
 369                         desc = blk_get_devnum_by_type(if_type, i);
 370                         if (!desc)
 371                                 continue;
 372                         if (desc->type == DEV_TYPE_UNKNOWN)
 373                                 continue;
 374
 375                         snprintf(devname, sizeof(devname), "%s%d",
 376                                  if_typename, i);
 377
 378                         /* add devices for each partition: */
 379                         for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
 380                                 if (part_get_info(desc, part, &info))
 381                                         continue;
 382                                 efi_disk_add_dev(devname, if_typename, desc,
 383                                                  i, 0, part);
 384                         }
 385
 386                         /* ... and add block device: */
 387                         efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
 388                         disks++;
 389
 390                         /*
 391                          * El Torito images show up as block devices
 392                          * in an EFI world, so let's create them here
 393                          */
 394                         disks += efi_disk_create_eltorito(desc, if_typename,
 395                                                           i, devname);
 396                 }
 397         }
 398 #endif
 399         printf("Found %d disks\n", disks);
 400
 401         return 0;
 402 }