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         /* Offset into disk for simple partitions */
  35         lbaint_t offset;
  36         /* Internal block device */
  37         struct blk_desc *desc;
  38 };
  39
  40 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  41                         char extended_verification)
  42 {
  43         EFI_ENTRY("%p, %x", this, extended_verification);
  44         return EFI_EXIT(EFI_DEVICE_ERROR);
  45 }
  46
  47 enum efi_disk_direction {
  48         EFI_DISK_READ,
  49         EFI_DISK_WRITE,
  50 };
  51
  52 static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
  53                         u32 media_id, u64 lba, unsigned long buffer_size,
  54                         void *buffer, enum efi_disk_direction direction)
  55 {
  56         struct efi_disk_obj *diskobj;
  57         struct blk_desc *desc;
  58         int blksz;
  59         int blocks;
  60         unsigned long n;
  61
  62         diskobj = container_of(this, struct efi_disk_obj, ops);
  63         desc = (struct blk_desc *) diskobj->desc;
  64         blksz = desc->blksz;
  65         blocks = buffer_size / blksz;
  66         lba += diskobj->offset;
  67
  68         debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  69               __LINE__, blocks, lba, blksz, direction);
  70
  71         /* We only support full block access */
  72         if (buffer_size & (blksz - 1))
  73                 return EFI_DEVICE_ERROR;
  74
  75         if (direction == EFI_DISK_READ)
  76                 n = blk_dread(desc, lba, blocks, buffer);
  77         else
  78                 n = blk_dwrite(desc, lba, blocks, buffer);
  79
  80         /* We don't do interrupts, so check for timers cooperatively */
  81         efi_timer_check();
  82
  83         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
  84
  85         if (n != blocks)
  86                 return EFI_DEVICE_ERROR;
  87
  88         return EFI_SUCCESS;
  89 }
  90
  91 static efi_status_t EFIAPI efi_disk_read_blocks(struct efi_block_io *this,
  92                         u32 media_id, u64 lba, unsigned long buffer_size,
  93                         void *buffer)
  94 {
  95         void *real_buffer = buffer;
  96         efi_status_t r;
  97
  98 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
  99         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 100                 r = efi_disk_read_blocks(this, media_id, lba,
 101                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 102                 if (r != EFI_SUCCESS)
 103                         return r;
 104                 return efi_disk_read_blocks(this, media_id, lba +
 105                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 106                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 107                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 108         }
 109
 110         real_buffer = efi_bounce_buffer;
 111 #endif
 112
 113         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 114                   buffer_size, buffer);
 115
 116         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 117                                EFI_DISK_READ);
 118
 119         /* Copy from bounce buffer to real buffer if necessary */
 120         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 121                 memcpy(buffer, real_buffer, buffer_size);
 122
 123         return EFI_EXIT(r);
 124 }
 125
 126 static efi_status_t EFIAPI efi_disk_write_blocks(struct efi_block_io *this,
 127                         u32 media_id, u64 lba, unsigned long buffer_size,
 128                         void *buffer)
 129 {
 130         void *real_buffer = buffer;
 131         efi_status_t r;
 132
 133 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 134         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 135                 r = efi_disk_write_blocks(this, media_id, lba,
 136                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 137                 if (r != EFI_SUCCESS)
 138                         return r;
 139                 return efi_disk_write_blocks(this, media_id, lba +
 140                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 141                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 142                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 143         }
 144
 145         real_buffer = efi_bounce_buffer;
 146 #endif
 147
 148         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 149                   buffer_size, buffer);
 150
 151         /* Populate bounce buffer if necessary */
 152         if (real_buffer != buffer)
 153                 memcpy(real_buffer, buffer, buffer_size);
 154
 155         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 156                                EFI_DISK_WRITE);
 157
 158         return EFI_EXIT(r);
 159 }
 160
 161 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 162 {
 163         /* We always write synchronously */
 164         EFI_ENTRY("%p", this);
 165         return EFI_EXIT(EFI_SUCCESS);
 166 }
 167
 168 static const struct efi_block_io block_io_disk_template = {
 169         .reset = &efi_disk_reset,
 170         .read_blocks = &efi_disk_read_blocks,
 171         .write_blocks = &efi_disk_write_blocks,
 172         .flush_blocks = &efi_disk_flush_blocks,
 173 };
 174
 175 static void efi_disk_add_dev(const char *name,
 176                              const char *if_typename,
 177                              struct blk_desc *desc,
 178                              int dev_index,
 179                              lbaint_t offset,
 180                              unsigned int part)
 181 {
 182         struct efi_disk_obj *diskobj;
 183
 184         /* Don't add empty devices */
 185         if (!desc->lba)
 186                 return;
 187
 188         diskobj = calloc(1, sizeof(*diskobj));
 189
 190         /* Fill in object data */
 191         diskobj->dp = efi_dp_from_part(desc, part);
 192         diskobj->part = part;
 193         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 194         diskobj->parent.protocols[0].protocol_interface = &diskobj->ops;
 195         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 196         diskobj->parent.protocols[1].protocol_interface = diskobj->dp;
 197         diskobj->parent.handle = diskobj;
 198         diskobj->ops = block_io_disk_template;
 199         diskobj->ifname = if_typename;
 200         diskobj->dev_index = dev_index;
 201         diskobj->offset = offset;
 202         diskobj->desc = desc;
 203
 204         /* Fill in EFI IO Media info (for read/write callbacks) */
 205         diskobj->media.removable_media = desc->removable;
 206         diskobj->media.media_present = 1;
 207         diskobj->media.block_size = desc->blksz;
 208         diskobj->media.io_align = desc->blksz;
 209         diskobj->media.last_block = desc->lba - offset;
 210         diskobj->ops.media = &diskobj->media;
 211
 212         /* Hook up to the device list */
 213         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 214 }
 215
 216 static int efi_disk_create_eltorito(struct blk_desc *desc,
 217                                     const char *if_typename,
 218                                     int diskid,
 219                                     const char *pdevname)
 220 {
 221         int disks = 0;
 222 #if CONFIG_IS_ENABLED(ISO_PARTITION)
 223         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 224         disk_partition_t info;
 225         int part = 1;
 226
 227         if (desc->part_type != PART_TYPE_ISO)
 228                 return 0;
 229
 230         /* and devices for each partition: */
 231         while (!part_get_info(desc, part, &info)) {
 232                 snprintf(devname, sizeof(devname), "%s:%d", pdevname,
 233                          part);
 234                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 235                                  info.start, part);
 236                 part++;
 237                 disks++;
 238         }
 239
 240         /* ... and add block device: */
 241         efi_disk_add_dev(devname, if_typename, desc, diskid, 0, 0);
 242 #endif
 243
 244         return disks;
 245 }
 246
 247 /*
 248  * U-Boot doesn't have a list of all online disk devices. So when running our
 249  * EFI payload, we scan through all of the potentially available ones and
 250  * store them in our object pool.
 251  *
 252  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 253  * Consider converting the code to look up devices as needed. The EFI device
 254  * could be a child of the UCLASS_BLK block device, perhaps.
 255  *
 256  * This gets called from do_bootefi_exec().
 257  */
 258 int efi_disk_register(void)
 259 {
 260         int disks = 0;
 261 #ifdef CONFIG_BLK
 262         struct udevice *dev;
 263
 264         for (uclass_first_device_check(UCLASS_BLK, &dev);
 265              dev;
 266              uclass_next_device_check(&dev)) {
 267                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 268                 const char *if_typename = dev->driver->name;
 269                 disk_partition_t info;
 270                 int part = 1;
 271
 272                 printf("Scanning disk %s...\n", dev->name);
 273
 274                 /* add devices for each partition: */
 275                 while (!part_get_info(desc, part, &info)) {
 276                         efi_disk_add_dev(dev->name, if_typename, desc,
 277                                          desc->devnum, 0, part);
 278                         part++;
 279                 }
 280
 281                 /* ... and add block device: */
 282                 efi_disk_add_dev(dev->name, if_typename, desc,
 283                                  desc->devnum, 0, 0);
 284
 285                 disks++;
 286
 287                 /*
 288                 * El Torito images show up as block devices in an EFI world,
 289                 * so let's create them here
 290                 */
 291                 disks += efi_disk_create_eltorito(desc, if_typename,
 292                                                   desc->devnum, dev->name);
 293         }
 294 #else
 295         int i, if_type;
 296
 297         /* Search for all available disk devices */
 298         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 299                 const struct blk_driver *cur_drvr;
 300                 const char *if_typename;
 301
 302                 cur_drvr = blk_driver_lookup_type(if_type);
 303                 if (!cur_drvr)
 304                         continue;
 305
 306                 if_typename = cur_drvr->if_typename;
 307                 printf("Scanning disks on %s...\n", if_typename);
 308                 for (i = 0; i < 4; i++) {
 309                         struct blk_desc *desc;
 310                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 311
 312                         desc = blk_get_devnum_by_type(if_type, i);
 313                         if (!desc)
 314                                 continue;
 315                         if (desc->type == DEV_TYPE_UNKNOWN)
 316                                 continue;
 317
 318                         snprintf(devname, sizeof(devname), "%s%d",
 319                                  if_typename, i);
 320                         efi_disk_add_dev(devname, if_typename, desc, i, 0, 0);
 321                         disks++;
 322
 323                         /*
 324                          * El Torito images show up as block devices
 325                          * in an EFI world, so let's create them here
 326                          */
 327                         disks += efi_disk_create_eltorito(desc, if_typename,
 328                                                           i, devname);
 329                 }
 330         }
 331 #endif
 332         printf("Found %d disks\n", disks);
 333
 334         return 0;
 335 }