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 static void efi_disk_add_dev(const char *name,
 200                              const char *if_typename,
 201                              struct blk_desc *desc,
 202                              int dev_index,
 203                              lbaint_t offset,
 204                              unsigned int part)
 205 {
 206         struct efi_disk_obj *diskobj;
 207
 208         /* Don't add empty devices */
 209         if (!desc->lba)
 210                 return;
 211
 212         diskobj = calloc(1, sizeof(*diskobj));
 213
 214         /* Fill in object data */
 215         diskobj->dp = efi_dp_from_part(desc, part);
 216         diskobj->part = part;
 217         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 218         diskobj->parent.protocols[0].protocol_interface = &diskobj->ops;
 219         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 220         diskobj->parent.protocols[1].protocol_interface = diskobj->dp;
 221         if (part >= 1) {
 222                 diskobj->volume = efi_simple_file_system(desc, part,
 223                                                          diskobj->dp);
 224                 diskobj->parent.protocols[2].guid =
 225                         &efi_simple_file_system_protocol_guid;
 226                 diskobj->parent.protocols[2].protocol_interface =
 227                         diskobj->volume;
 228         }
 229         diskobj->parent.handle = diskobj;
 230         diskobj->ops = block_io_disk_template;
 231         diskobj->ifname = if_typename;
 232         diskobj->dev_index = dev_index;
 233         diskobj->offset = offset;
 234         diskobj->desc = desc;
 235
 236         /* Fill in EFI IO Media info (for read/write callbacks) */
 237         diskobj->media.removable_media = desc->removable;
 238         diskobj->media.media_present = 1;
 239         diskobj->media.block_size = desc->blksz;
 240         diskobj->media.io_align = desc->blksz;
 241         diskobj->media.last_block = desc->lba - offset;
 242         diskobj->ops.media = &diskobj->media;
 243
 244         /* Hook up to the device list */
 245         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 246 }
 247
 248 static int efi_disk_create_eltorito(struct blk_desc *desc,
 249                                     const char *if_typename,
 250                                     int diskid,
 251                                     const char *pdevname)
 252 {
 253         int disks = 0;
 254 #if CONFIG_IS_ENABLED(ISO_PARTITION)
 255         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 256         disk_partition_t info;
 257         int part = 1;
 258
 259         if (desc->part_type != PART_TYPE_ISO)
 260                 return 0;
 261
 262         /* and devices for each partition: */
 263         while (!part_get_info(desc, part, &info)) {
 264                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 265                          part);
 266                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 267                                  info.start, part);
 268                 part++;
 269                 disks++;
 270         }
 271
 272         /* ... and add block device: */
 273         efi_disk_add_dev(devname, if_typename, desc, diskid, 0, 0);
 274 #endif
 275
 276         return disks;
 277 }
 278
 279 /*
 280  * U-Boot doesn't have a list of all online disk devices. So when running our
 281  * EFI payload, we scan through all of the potentially available ones and
 282  * store them in our object pool.
 283  *
 284  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 285  * Consider converting the code to look up devices as needed. The EFI device
 286  * could be a child of the UCLASS_BLK block device, perhaps.
 287  *
 288  * This gets called from do_bootefi_exec().
 289  */
 290 int efi_disk_register(void)
 291 {
 292         int disks = 0;
 293 #ifdef CONFIG_BLK
 294         struct udevice *dev;
 295
 296         for (uclass_first_device_check(UCLASS_BLK, &dev);
 297              dev;
 298              uclass_next_device_check(&dev)) {
 299                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 300                 const char *if_typename = dev->driver->name;
 301                 disk_partition_t info;
 302                 int part = 1;
 303
 304                 printf("Scanning disk %s...\n", dev->name);
 305
 306                 /* add devices for each partition: */
 307                 while (!part_get_info(desc, part, &info)) {
 308                         efi_disk_add_dev(dev->name, if_typename, desc,
 309                                          desc->devnum, 0, part);
 310                         part++;
 311                 }
 312
 313                 /* ... and add block device: */
 314                 efi_disk_add_dev(dev->name, if_typename, desc,
 315                                  desc->devnum, 0, 0);
 316
 317                 disks++;
 318
 319                 /*
 320                 * El Torito images show up as block devices in an EFI world,
 321                 * so let's create them here
 322                 */
 323                 disks += efi_disk_create_eltorito(desc, if_typename,
 324                                                   desc->devnum, dev->name);
 325         }
 326 #else
 327         int i, if_type;
 328
 329         /* Search for all available disk devices */
 330         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 331                 const struct blk_driver *cur_drvr;
 332                 const char *if_typename;
 333
 334                 cur_drvr = blk_driver_lookup_type(if_type);
 335                 if (!cur_drvr)
 336                         continue;
 337
 338                 if_typename = cur_drvr->if_typename;
 339                 printf("Scanning disks on %s...\n", if_typename);
 340                 for (i = 0; i < 4; i++) {
 341                         struct blk_desc *desc;
 342                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 343                         disk_partition_t info;
 344                         int part = 1;
 345
 346                         desc = blk_get_devnum_by_type(if_type, i);
 347                         if (!desc)
 348                                 continue;
 349                         if (desc->type == DEV_TYPE_UNKNOWN)
 350                                 continue;
 351
 352                         snprintf(devname, sizeof(devname), "%s%d",
 353                                  if_typename, i);
 354
 355                         /* add devices for each partition: */
 356                         while (!part_get_info(desc, part, &info)) {
 357                                 efi_disk_add_dev(devname, if_typename, desc,
 358                                                  i, 0, part);
 359                                 part++;
 360                         }
 361
 362                         /* ... and add block device: */
 363                         efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
 364                         disks++;
 365
 366                         /*
 367                          * El Torito images show up as block devices
 368                          * in an EFI world, so let's create them here
 369                          */
 370                         disks += efi_disk_create_eltorito(desc, if_typename,
 371                                                           i, devname);
 372                 }
 373         }
 374 #endif
 375         printf("Found %d disks\n", disks);
 376
 377         return 0;
 378 }