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  * Get the simple file system protocol for a file device path.
 179  *
 180  * The full path provided is split into device part and into a file
 181  * part. The device part is used to find the handle on which the
 182  * simple file system protocol is installed.
 183  *
 184  * @full_path   device path including device and file
 185  * @return      simple file system protocol
 186  */
 187 struct efi_simple_file_system_protocol *
 188 efi_fs_from_path(struct efi_device_path *full_path)
 189 {
 190         struct efi_object *efiobj;
 191         struct efi_handler *handler;
 192         struct efi_device_path *device_path;
 193         struct efi_device_path *file_path;
 194         efi_status_t ret;
 195
 196         /* Split the path into a device part and a file part */
 197         ret = efi_dp_split_file_path(full_path, &device_path, &file_path);
 198         if (ret != EFI_SUCCESS)
 199                 return NULL;
 200         efi_free_pool(file_path);
 201
 202         /* Get the EFI object for the partition */
 203         efiobj = efi_dp_find_obj(device_path, NULL);
 204         efi_free_pool(device_path);
 205         if (!efiobj)
 206                 return NULL;
 207
 208         /* Find the simple file system protocol */
 209         ret = efi_search_protocol(efiobj, &efi_simple_file_system_protocol_guid,
 210                                   &handler);
 211         if (ret != EFI_SUCCESS)
 212                 return NULL;
 213
 214         /* Return the simple file system protocol for the partition */
 215         return handler->protocol_interface;
 216 }
 217
 218 /*
 219  * Create a device for a disk
 220  *
 221  * @name        not used
 222  * @if_typename interface name for block device
 223  * @desc        internal block device
 224  * @dev_index   device index for block device
 225  * @offset      offset into disk for simple partitions
 226  */
 227 static void efi_disk_add_dev(const char *name,
 228                              const char *if_typename,
 229                              struct blk_desc *desc,
 230                              int dev_index,
 231                              lbaint_t offset,
 232                              unsigned int part)
 233 {
 234         struct efi_disk_obj *diskobj;
 235         efi_status_t ret;
 236
 237         /* Don't add empty devices */
 238         if (!desc->lba)
 239                 return;
 240
 241         diskobj = calloc(1, sizeof(*diskobj));
 242         if (!diskobj)
 243                 goto out_of_memory;
 244
 245         /* Hook up to the device list */
 246         efi_add_handle(&diskobj->parent);
 247
 248         /* Fill in object data */
 249         diskobj->dp = efi_dp_from_part(desc, part);
 250         diskobj->part = part;
 251         ret = efi_add_protocol(diskobj->parent.handle, &efi_block_io_guid,
 252                                &diskobj->ops);
 253         if (ret != EFI_SUCCESS)
 254                 goto out_of_memory;
 255         ret = efi_add_protocol(diskobj->parent.handle, &efi_guid_device_path,
 256                                diskobj->dp);
 257         if (ret != EFI_SUCCESS)
 258                 goto out_of_memory;
 259         if (part >= 1) {
 260                 diskobj->volume = efi_simple_file_system(desc, part,
 261                                                          diskobj->dp);
 262                 ret = efi_add_protocol(diskobj->parent.handle,
 263                                        &efi_simple_file_system_protocol_guid,
 264                                        diskobj->volume);
 265                 if (ret != EFI_SUCCESS)
 266                         goto out_of_memory;
 267         }
 268         diskobj->ops = block_io_disk_template;
 269         diskobj->ifname = if_typename;
 270         diskobj->dev_index = dev_index;
 271         diskobj->offset = offset;
 272         diskobj->desc = desc;
 273
 274         /* Fill in EFI IO Media info (for read/write callbacks) */
 275         diskobj->media.removable_media = desc->removable;
 276         diskobj->media.media_present = 1;
 277         diskobj->media.block_size = desc->blksz;
 278         diskobj->media.io_align = desc->blksz;
 279         diskobj->media.last_block = desc->lba - offset;
 280         if (part != 0)
 281                 diskobj->media.logical_partition = 1;
 282         diskobj->ops.media = &diskobj->media;
 283         return;
 284 out_of_memory:
 285         printf("ERROR: Out of memory\n");
 286 }
 287
 288 static int efi_disk_create_partitions(struct blk_desc *desc,
 289                                       const char *if_typename,
 290                                       int diskid,
 291                                       const char *pdevname)
 292 {
 293         int disks = 0;
 294         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 295         disk_partition_t info;
 296         int part;
 297
 298         /* Add devices for each partition */
 299         for (part = 1; part <= MAX_SEARCH_PARTITIONS; part++) {
 300                 if (part_get_info(desc, part, &info))
 301                         continue;
 302                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 303                          part);
 304                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 305                                  info.start, part);
 306                 disks++;
 307         }
 308
 309         return disks;
 310 }
 311
 312 /*
 313  * U-Boot doesn't have a list of all online disk devices. So when running our
 314  * EFI payload, we scan through all of the potentially available ones and
 315  * store them in our object pool.
 316  *
 317  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 318  * Consider converting the code to look up devices as needed. The EFI device
 319  * could be a child of the UCLASS_BLK block device, perhaps.
 320  *
 321  * This gets called from do_bootefi_exec().
 322  */
 323 int efi_disk_register(void)
 324 {
 325         int disks = 0;
 326 #ifdef CONFIG_BLK
 327         struct udevice *dev;
 328
 329         for (uclass_first_device_check(UCLASS_BLK, &dev);
 330              dev;
 331              uclass_next_device_check(&dev)) {
 332                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 333                 const char *if_typename = dev->driver->name;
 334
 335                 printf("Scanning disk %s...\n", dev->name);
 336
 337                 /* Add block device for the full device */
 338                 efi_disk_add_dev(dev->name, if_typename, desc,
 339                                  desc->devnum, 0, 0);
 340
 341                 disks++;
 342
 343                 /* Partitions show up as block devices in EFI */
 344                 disks += efi_disk_create_partitions(desc, if_typename,
 345                                                     desc->devnum, dev->name);
 346         }
 347 #else
 348         int i, if_type;
 349
 350         /* Search for all available disk devices */
 351         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 352                 const struct blk_driver *cur_drvr;
 353                 const char *if_typename;
 354
 355                 cur_drvr = blk_driver_lookup_type(if_type);
 356                 if (!cur_drvr)
 357                         continue;
 358
 359                 if_typename = cur_drvr->if_typename;
 360                 printf("Scanning disks on %s...\n", if_typename);
 361                 for (i = 0; i < 4; i++) {
 362                         struct blk_desc *desc;
 363                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 364
 365                         desc = blk_get_devnum_by_type(if_type, i);
 366                         if (!desc)
 367                                 continue;
 368                         if (desc->type == DEV_TYPE_UNKNOWN)
 369                                 continue;
 370
 371                         snprintf(devname, sizeof(devname), "%s%d",
 372                                  if_typename, i);
 373
 374                         /* Add block device for the full device */
 375                         efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
 376                         disks++;
 377
 378                         /* Partitions show up as block devices in EFI */
 379                         disks += efi_disk_create_partitions(desc, if_typename,
 380                                                             i, devname);
 381                 }
 382         }
 383 #endif
 384         printf("Found %d disks\n", disks);
 385
 386         return 0;
 387 }