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