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_file_path *dp;
  32         /* Offset into disk for simple partitions */
  33         lbaint_t offset;
  34         /* Internal block device */
  35         const struct blk_desc *desc;
  36 };
  37
  38 static efi_status_t EFIAPI efi_disk_open_block(void *handle,
  39                         efi_guid_t *protocol, void **protocol_interface,
  40                         void *agent_handle, void *controller_handle,
  41                         uint32_t attributes)
  42 {
  43         struct efi_disk_obj *diskobj = handle;
  44
  45         *protocol_interface = &diskobj->ops;
  46
  47         return EFI_SUCCESS;
  48 }
  49
  50 static efi_status_t EFIAPI efi_disk_open_dp(void *handle, efi_guid_t *protocol,
  51                         void **protocol_interface, void *agent_handle,
  52                         void *controller_handle, uint32_t attributes)
  53 {
  54         struct efi_disk_obj *diskobj = handle;
  55
  56         *protocol_interface = diskobj->dp;
  57
  58         return EFI_SUCCESS;
  59 }
  60
  61 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  62                         char extended_verification)
  63 {
  64         EFI_ENTRY("%p, %x", this, extended_verification);
  65         return EFI_EXIT(EFI_DEVICE_ERROR);
  66 }
  67
  68 enum efi_disk_direction {
  69         EFI_DISK_READ,
  70         EFI_DISK_WRITE,
  71 };
  72
  73 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
  74                         u32 media_id, u64 lba, unsigned long buffer_size,
  75                         void *buffer, enum efi_disk_direction direction)
  76 {
  77         struct efi_disk_obj *diskobj;
  78         struct blk_desc *desc;
  79         int blksz;
  80         int blocks;
  81         unsigned long n;
  82
  83         diskobj = container_of(this, struct efi_disk_obj, ops);
  84         desc = (struct blk_desc *) diskobj->desc;
  85         blksz = desc->blksz;
  86         blocks = buffer_size / blksz;
  87         lba += diskobj->offset;
  88
  89         debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  90               __LINE__, blocks, lba, blksz, direction);
  91
  92         /* We only support full block access */
  93         if (buffer_size & (blksz - 1))
  94                 return EFI_EXIT(EFI_DEVICE_ERROR);
  95
  96         if (direction == EFI_DISK_READ)
  97                 n = blk_dread(desc, lba, blocks, buffer);
  98         else
  99                 n = blk_dwrite(desc, lba, blocks, buffer);
 100
 101         /* We don't do interrupts, so check for timers cooperatively */
 102         efi_timer_check();
 103
 104         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
 105
 106         if (n != blocks)
 107                 return EFI_EXIT(EFI_DEVICE_ERROR);
 108
 109         return EFI_EXIT(EFI_SUCCESS);
 110 }
 111
 112 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
 113                         u32 media_id, u64 lba, unsigned long buffer_size,
 114                         void *buffer)
 115 {
 116         void *real_buffer = buffer;
 117         efi_status_t r;
 118
 119 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 120         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 121                 r = efi_disk_read_blocks(this, media_id, lba,
 122                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 123                 if (r != EFI_SUCCESS)
 124                         return r;
 125                 return efi_disk_read_blocks(this, media_id, lba +
 126                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 127                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 128                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 129         }
 130
 131         real_buffer = efi_bounce_buffer;
 132 #endif
 133
 134         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 135                   buffer_size, buffer);
 136
 137         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 138                                EFI_DISK_READ);
 139
 140         /* Copy from bounce buffer to real buffer if necessary */
 141         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 142                 memcpy(buffer, real_buffer, buffer_size);
 143
 144         return EFI_EXIT(r);
 145 }
 146
 147 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
 148                         u32 media_id, u64 lba, unsigned long buffer_size,
 149                         void *buffer)
 150 {
 151         void *real_buffer = buffer;
 152         efi_status_t r;
 153
 154 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 155         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 156                 r = efi_disk_write_blocks(this, media_id, lba,
 157                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 158                 if (r != EFI_SUCCESS)
 159                         return r;
 160                 return efi_disk_write_blocks(this, media_id, lba +
 161                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 162                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 163                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 164         }
 165
 166         real_buffer = efi_bounce_buffer;
 167 #endif
 168
 169         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 170                   buffer_size, buffer);
 171
 172         /* Populate bounce buffer if necessary */
 173         if (real_buffer != buffer)
 174                 memcpy(real_buffer, buffer, buffer_size);
 175
 176         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 177                                EFI_DISK_WRITE);
 178
 179         return EFI_EXIT(r);
 180 }
 181
 182 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 183 {
 184         /* We always write synchronously */
 185         EFI_ENTRY("%p", this);
 186         return EFI_EXIT(EFI_SUCCESS);
 187 }
 188
 189 static const struct efi_block_io block_io_disk_template = {
 190         .reset = &efi_disk_reset,
 191         .read_blocks = &efi_disk_read_blocks,
 192         .write_blocks = &efi_disk_write_blocks,
 193         .flush_blocks = &efi_disk_flush_blocks,
 194 };
 195
 196 static void efi_disk_add_dev(const char *name,
 197                              const char *if_typename,
 198                              const struct blk_desc *desc,
 199                              int dev_index,
 200                              lbaint_t offset)
 201 {
 202         struct efi_disk_obj *diskobj;
 203         struct efi_device_path_file_path *dp;
 204         int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
 205
 206         /* Don't add empty devices */
 207         if (!desc->lba)
 208                 return;
 209
 210         diskobj = calloc(1, objlen);
 211
 212         /* Fill in object data */
 213         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 214         diskobj->parent.protocols[0].open = efi_disk_open_block;
 215         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 216         diskobj->parent.protocols[1].open = efi_disk_open_dp;
 217         diskobj->parent.handle = diskobj;
 218         diskobj->ops = block_io_disk_template;
 219         diskobj->ifname = if_typename;
 220         diskobj->dev_index = dev_index;
 221         diskobj->offset = offset;
 222         diskobj->desc = desc;
 223
 224         /* Fill in EFI IO Media info (for read/write callbacks) */
 225         diskobj->media.removable_media = desc->removable;
 226         diskobj->media.media_present = 1;
 227         diskobj->media.block_size = desc->blksz;
 228         diskobj->media.io_align = desc->blksz;
 229         diskobj->media.last_block = desc->lba - offset;
 230         diskobj->ops.media = &diskobj->media;
 231
 232         /* Fill in device path */
 233         dp = (void*)&diskobj[1];
 234         diskobj->dp = dp;
 235         dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 236         dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 237         dp[0].dp.length = sizeof(*dp);
 238         ascii2unicode(dp[0].str, name);
 239
 240         dp[1].dp.type = DEVICE_PATH_TYPE_END;
 241         dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
 242         dp[1].dp.length = sizeof(*dp);
 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         while (!part_get_info(desc, part, &info)) {
 263                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 264                          part);
 265                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 266                                  info.start);
 267                 part++;
 268                 disks++;
 269         }
 270 #endif
 271
 272         return disks;
 273 }
 274
 275 /*
 276  * U-Boot doesn't have a list of all online disk devices. So when running our
 277  * EFI payload, we scan through all of the potentially available ones and
 278  * store them in our object pool.
 279  *
 280  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 281  * Consider converting the code to look up devices as needed. The EFI device
 282  * could be a child of the UCLASS_BLK block device, perhaps.
 283  *
 284  * This gets called from do_bootefi_exec().
 285  */
 286 int efi_disk_register(void)
 287 {
 288         int disks = 0;
 289 #ifdef CONFIG_BLK
 290         struct udevice *dev;
 291
 292         for (uclass_first_device(UCLASS_BLK, &dev);
 293              dev;
 294              uclass_next_device(&dev)) {
 295                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 296                 const char *if_typename = dev->driver->name;
 297
 298                 printf("Scanning disk %s...\n", dev->name);
 299                 efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
 300                 disks++;
 301
 302                 /*
 303                 * El Torito images show up as block devices in an EFI world,
 304                 * so let's create them here
 305                 */
 306                 disks += efi_disk_create_eltorito(desc, if_typename,
 307                                                   desc->devnum, dev->name);
 308         }
 309 #else
 310         int i, if_type;
 311
 312         /* Search for all available disk devices */
 313         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 314                 const struct blk_driver *cur_drvr;
 315                 const char *if_typename;
 316
 317                 cur_drvr = blk_driver_lookup_type(if_type);
 318                 if (!cur_drvr)
 319                         continue;
 320
 321                 if_typename = cur_drvr->if_typename;
 322                 printf("Scanning disks on %s...\n", if_typename);
 323                 for (i = 0; i < 4; i++) {
 324                         struct blk_desc *desc;
 325                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 326
 327                         desc = blk_get_devnum_by_type(if_type, i);
 328                         if (!desc)
 329                                 continue;
 330                         if (desc->type == DEV_TYPE_UNKNOWN)
 331                                 continue;
 332
 333                         snprintf(devname, sizeof(devname), "%s%d",
 334                                  if_typename, i);
 335                         efi_disk_add_dev(devname, if_typename, desc, i, 0);
 336                         disks++;
 337
 338                         /*
 339                          * El Torito images show up as block devices
 340                          * in an EFI world, so let's create them here
 341                          */
 342                         disks += efi_disk_create_eltorito(desc, if_typename,
 343                                                           i, devname);
 344                 }
 345         }
 346 #endif
 347         printf("Found %d disks\n", disks);
 348
 349         return 0;
 350 }