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 efi_disk_open_block(void *handle, efi_guid_t *protocol,
  39                         void **protocol_interface, void *agent_handle,
  40                         void *controller_handle, uint32_t attributes)
  41 {
  42         struct efi_disk_obj *diskobj = handle;
  43
  44         *protocol_interface = &diskobj->ops;
  45
  46         return EFI_SUCCESS;
  47 }
  48
  49 static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
  50                         void **protocol_interface, void *agent_handle,
  51                         void *controller_handle, uint32_t attributes)
  52 {
  53         struct efi_disk_obj *diskobj = handle;
  54
  55         *protocol_interface = diskobj->dp;
  56
  57         return EFI_SUCCESS;
  58 }
  59
  60 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  61                         char extended_verification)
  62 {
  63         EFI_ENTRY("%p, %x", this, extended_verification);
  64         return EFI_EXIT(EFI_DEVICE_ERROR);
  65 }
  66
  67 enum efi_disk_direction {
  68         EFI_DISK_READ,
  69         EFI_DISK_WRITE,
  70 };
  71
  72 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
  73                         u32 media_id, u64 lba, unsigned long buffer_size,
  74                         void *buffer, enum efi_disk_direction direction)
  75 {
  76         struct efi_disk_obj *diskobj;
  77         struct blk_desc *desc;
  78         int blksz;
  79         int blocks;
  80         unsigned long n;
  81
  82         diskobj = container_of(this, struct efi_disk_obj, ops);
  83         desc = (struct blk_desc *) diskobj->desc;
  84         blksz = desc->blksz;
  85         blocks = buffer_size / blksz;
  86         lba += diskobj->offset;
  87
  88         debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  89               __LINE__, blocks, lba, blksz, direction);
  90
  91         /* We only support full block access */
  92         if (buffer_size & (blksz - 1))
  93                 return EFI_EXIT(EFI_DEVICE_ERROR);
  94
  95         if (direction == EFI_DISK_READ)
  96                 n = blk_dread(desc, lba, blocks, buffer);
  97         else
  98                 n = blk_dwrite(desc, lba, blocks, buffer);
  99
 100         /* We don't do interrupts, so check for timers cooperatively */
 101         efi_timer_check();
 102
 103         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
 104
 105         if (n != blocks)
 106                 return EFI_EXIT(EFI_DEVICE_ERROR);
 107
 108         return EFI_EXIT(EFI_SUCCESS);
 109 }
 110
 111 static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
 112                         u32 media_id, u64 lba, unsigned long buffer_size,
 113                         void *buffer)
 114 {
 115         void *real_buffer = buffer;
 116         efi_status_t r;
 117
 118 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 119         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 120                 r = efi_disk_read_blocks(this, media_id, lba,
 121                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 122                 if (r != EFI_SUCCESS)
 123                         return r;
 124                 return efi_disk_read_blocks(this, media_id, lba +
 125                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 126                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 127                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 128         }
 129
 130         real_buffer = efi_bounce_buffer;
 131 #endif
 132
 133         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 134                   buffer_size, buffer);
 135
 136         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 137                                EFI_DISK_READ);
 138
 139         /* Copy from bounce buffer to real buffer if necessary */
 140         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 141                 memcpy(buffer, real_buffer, buffer_size);
 142
 143         return EFI_EXIT(r);
 144 }
 145
 146 static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
 147                         u32 media_id, u64 lba, unsigned long buffer_size,
 148                         void *buffer)
 149 {
 150         void *real_buffer = buffer;
 151         efi_status_t r;
 152
 153 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 154         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 155                 r = efi_disk_write_blocks(this, media_id, lba,
 156                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 157                 if (r != EFI_SUCCESS)
 158                         return r;
 159                 return efi_disk_write_blocks(this, media_id, lba +
 160                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 161                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 162                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 163         }
 164
 165         real_buffer = efi_bounce_buffer;
 166 #endif
 167
 168         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 169                   buffer_size, buffer);
 170
 171         /* Populate bounce buffer if necessary */
 172         if (real_buffer != buffer)
 173                 memcpy(real_buffer, buffer, buffer_size);
 174
 175         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 176                                EFI_DISK_WRITE);
 177
 178         return EFI_EXIT(r);
 179 }
 180
 181 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 182 {
 183         /* We always write synchronously */
 184         EFI_ENTRY("%p", this);
 185         return EFI_EXIT(EFI_SUCCESS);
 186 }
 187
 188 static const struct efi_block_io block_io_disk_template = {
 189         .reset = &efi_disk_reset,
 190         .read_blocks = &efi_disk_read_blocks,
 191         .write_blocks = &efi_disk_write_blocks,
 192         .flush_blocks = &efi_disk_flush_blocks,
 193 };
 194
 195 static void efi_disk_add_dev(const char *name,
 196                              const char *if_typename,
 197                              const struct blk_desc *desc,
 198                              int dev_index,
 199                              lbaint_t offset)
 200 {
 201         struct efi_disk_obj *diskobj;
 202         struct efi_device_path_file_path *dp;
 203         int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
 204
 205         /* Don't add empty devices */
 206         if (!desc->lba)
 207                 return;
 208
 209         diskobj = calloc(1, objlen);
 210
 211         /* Fill in object data */
 212         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 213         diskobj->parent.protocols[0].open = efi_disk_open_block;
 214         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 215         diskobj->parent.protocols[1].open = efi_disk_open_dp;
 216         diskobj->parent.handle = diskobj;
 217         diskobj->ops = block_io_disk_template;
 218         diskobj->ifname = if_typename;
 219         diskobj->dev_index = dev_index;
 220         diskobj->offset = offset;
 221         diskobj->desc = desc;
 222
 223         /* Fill in EFI IO Media info (for read/write callbacks) */
 224         diskobj->media.removable_media = desc->removable;
 225         diskobj->media.media_present = 1;
 226         diskobj->media.block_size = desc->blksz;
 227         diskobj->media.io_align = desc->blksz;
 228         diskobj->media.last_block = desc->lba - offset;
 229         diskobj->ops.media = &diskobj->media;
 230
 231         /* Fill in device path */
 232         dp = (void*)&diskobj[1];
 233         diskobj->dp = dp;
 234         dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 235         dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 236         dp[0].dp.length = sizeof(*dp);
 237         ascii2unicode(dp[0].str, name);
 238
 239         dp[1].dp.type = DEVICE_PATH_TYPE_END;
 240         dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
 241         dp[1].dp.length = sizeof(*dp);
 242
 243         /* Hook up to the device list */
 244         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 245 }
 246
 247 static int efi_disk_create_eltorito(struct blk_desc *desc,
 248                                     const char *if_typename,
 249                                     int diskid,
 250                                     const char *pdevname)
 251 {
 252         int disks = 0;
 253 #ifdef CONFIG_ISO_PARTITION
 254         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 255         disk_partition_t info;
 256         int part = 1;
 257
 258         if (desc->part_type != PART_TYPE_ISO)
 259                 return 0;
 260
 261         while (!part_get_info(desc, part, &info)) {
 262                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 263                          part);
 264                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 265                                  info.start);
 266                 part++;
 267                 disks++;
 268         }
 269 #endif
 270
 271         return disks;
 272 }
 273
 274 /*
 275  * U-Boot doesn't have a list of all online disk devices. So when running our
 276  * EFI payload, we scan through all of the potentially available ones and
 277  * store them in our object pool.
 278  *
 279  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 280  * Consider converting the code to look up devices as needed. The EFI device
 281  * could be a child of the UCLASS_BLK block device, perhaps.
 282  *
 283  * This gets called from do_bootefi_exec().
 284  */
 285 int efi_disk_register(void)
 286 {
 287         int disks = 0;
 288 #ifdef CONFIG_BLK
 289         struct udevice *dev;
 290
 291         for (uclass_first_device(UCLASS_BLK, &dev);
 292              dev;
 293              uclass_next_device(&dev)) {
 294                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 295                 const char *if_typename = dev->driver->name;
 296
 297                 printf("Scanning disk %s...\n", dev->name);
 298                 efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
 299                 disks++;
 300
 301                 /*
 302                 * El Torito images show up as block devices in an EFI world,
 303                 * so let's create them here
 304                 */
 305                 disks += efi_disk_create_eltorito(desc, if_typename,
 306                                                   desc->devnum, dev->name);
 307         }
 308 #else
 309         int i, if_type;
 310
 311         /* Search for all available disk devices */
 312         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 313                 const struct blk_driver *cur_drvr;
 314                 const char *if_typename;
 315
 316                 cur_drvr = blk_driver_lookup_type(if_type);
 317                 if (!cur_drvr)
 318                         continue;
 319
 320                 if_typename = cur_drvr->if_typename;
 321                 printf("Scanning disks on %s...\n", if_typename);
 322                 for (i = 0; i < 4; i++) {
 323                         struct blk_desc *desc;
 324                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 325
 326                         desc = blk_get_devnum_by_type(if_type, i);
 327                         if (!desc)
 328                                 continue;
 329                         if (desc->type == DEV_TYPE_UNKNOWN)
 330                                 continue;
 331
 332                         snprintf(devname, sizeof(devname), "%s%d",
 333                                  if_typename, i);
 334                         efi_disk_add_dev(devname, if_typename, desc, i, 0);
 335                         disks++;
 336
 337                         /*
 338                          * El Torito images show up as block devices
 339                          * in an EFI world, so let's create them here
 340                          */
 341                         disks += efi_disk_create_eltorito(desc, if_typename,
 342                                                           i, devname);
 343                 }
 344         }
 345 #endif
 346         printf("Found %d disks\n", disks);
 347
 348         return 0;
 349 }