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 };
  35
  36 static efi_status_t efi_disk_open_block(void *handle, efi_guid_t *protocol,
  37                         void **protocol_interface, void *agent_handle,
  38                         void *controller_handle, uint32_t attributes)
  39 {
  40         struct efi_disk_obj *diskobj = handle;
  41
  42         *protocol_interface = &diskobj->ops;
  43
  44         return EFI_SUCCESS;
  45 }
  46
  47 static efi_status_t efi_disk_open_dp(void *handle, efi_guid_t *protocol,
  48                         void **protocol_interface, void *agent_handle,
  49                         void *controller_handle, uint32_t attributes)
  50 {
  51         struct efi_disk_obj *diskobj = handle;
  52
  53         *protocol_interface = diskobj->dp;
  54
  55         return EFI_SUCCESS;
  56 }
  57
  58 static efi_status_t EFIAPI efi_disk_reset(struct efi_block_io *this,
  59                         char extended_verification)
  60 {
  61         EFI_ENTRY("%p, %x", this, extended_verification);
  62         return EFI_EXIT(EFI_DEVICE_ERROR);
  63 }
  64
  65 enum efi_disk_direction {
  66         EFI_DISK_READ,
  67         EFI_DISK_WRITE,
  68 };
  69
  70 static efi_status_t EFIAPI efi_disk_rw_blocks(struct efi_block_io *this,
  71                         u32 media_id, u64 lba, unsigned long buffer_size,
  72                         void *buffer, enum efi_disk_direction direction)
  73 {
  74         struct efi_disk_obj *diskobj;
  75         struct blk_desc *desc;
  76         int blksz;
  77         int blocks;
  78         unsigned long n;
  79
  80         diskobj = container_of(this, struct efi_disk_obj, ops);
  81         if (!(desc = blk_get_dev(diskobj->ifname, diskobj->dev_index)))
  82                 return EFI_EXIT(EFI_DEVICE_ERROR);
  83         blksz = desc->blksz;
  84         blocks = buffer_size / blksz;
  85         lba += diskobj->offset;
  86
  87         debug("EFI: %s:%d blocks=%x lba=%"PRIx64" blksz=%x dir=%d\n", __func__,
  88               __LINE__, blocks, lba, blksz, direction);
  89
  90         /* We only support full block access */
  91         if (buffer_size & (blksz - 1))
  92                 return EFI_EXIT(EFI_DEVICE_ERROR);
  93
  94         if (direction == EFI_DISK_READ)
  95                 n = blk_dread(desc, lba, blocks, buffer);
  96         else
  97                 n = blk_dwrite(desc, lba, blocks, buffer);
  98
  99         /* We don't do interrupts, so check for timers cooperatively */
 100         efi_timer_check();
 101
 102         debug("EFI: %s:%d n=%lx blocks=%x\n", __func__, __LINE__, n, blocks);
 103
 104         if (n != blocks)
 105                 return EFI_EXIT(EFI_DEVICE_ERROR);
 106
 107         return EFI_EXIT(EFI_SUCCESS);
 108 }
 109
 110 static efi_status_t efi_disk_read_blocks(struct efi_block_io *this,
 111                         u32 media_id, u64 lba, unsigned long buffer_size,
 112                         void *buffer)
 113 {
 114         void *real_buffer = buffer;
 115         efi_status_t r;
 116
 117 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 118         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 119                 r = efi_disk_read_blocks(this, media_id, lba,
 120                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 121                 if (r != EFI_SUCCESS)
 122                         return r;
 123                 return efi_disk_read_blocks(this, media_id, lba +
 124                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 125                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 126                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 127         }
 128
 129         real_buffer = efi_bounce_buffer;
 130 #endif
 131
 132         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 133                   buffer_size, buffer);
 134
 135         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 136                                EFI_DISK_READ);
 137
 138         /* Copy from bounce buffer to real buffer if necessary */
 139         if ((r == EFI_SUCCESS) && (real_buffer != buffer))
 140                 memcpy(buffer, real_buffer, buffer_size);
 141
 142         return EFI_EXIT(r);
 143 }
 144
 145 static efi_status_t efi_disk_write_blocks(struct efi_block_io *this,
 146                         u32 media_id, u64 lba, unsigned long buffer_size,
 147                         void *buffer)
 148 {
 149         void *real_buffer = buffer;
 150         efi_status_t r;
 151
 152 #ifdef CONFIG_EFI_LOADER_BOUNCE_BUFFER
 153         if (buffer_size > EFI_LOADER_BOUNCE_BUFFER_SIZE) {
 154                 r = efi_disk_write_blocks(this, media_id, lba,
 155                         EFI_LOADER_BOUNCE_BUFFER_SIZE, buffer);
 156                 if (r != EFI_SUCCESS)
 157                         return r;
 158                 return efi_disk_write_blocks(this, media_id, lba +
 159                         EFI_LOADER_BOUNCE_BUFFER_SIZE / this->media->block_size,
 160                         buffer_size - EFI_LOADER_BOUNCE_BUFFER_SIZE,
 161                         buffer + EFI_LOADER_BOUNCE_BUFFER_SIZE);
 162         }
 163
 164         real_buffer = efi_bounce_buffer;
 165 #endif
 166
 167         EFI_ENTRY("%p, %x, %"PRIx64", %lx, %p", this, media_id, lba,
 168                   buffer_size, buffer);
 169
 170         /* Populate bounce buffer if necessary */
 171         if (real_buffer != buffer)
 172                 memcpy(real_buffer, buffer, buffer_size);
 173
 174         r = efi_disk_rw_blocks(this, media_id, lba, buffer_size, real_buffer,
 175                                EFI_DISK_WRITE);
 176
 177         return EFI_EXIT(r);
 178 }
 179
 180 static efi_status_t EFIAPI efi_disk_flush_blocks(struct efi_block_io *this)
 181 {
 182         /* We always write synchronously */
 183         EFI_ENTRY("%p", this);
 184         return EFI_EXIT(EFI_SUCCESS);
 185 }
 186
 187 static const struct efi_block_io block_io_disk_template = {
 188         .reset = &efi_disk_reset,
 189         .read_blocks = &efi_disk_read_blocks,
 190         .write_blocks = &efi_disk_write_blocks,
 191         .flush_blocks = &efi_disk_flush_blocks,
 192 };
 193
 194 static void efi_disk_add_dev(const char *name,
 195                              const char *if_typename,
 196                              const struct blk_desc *desc,
 197                              int dev_index,
 198                              lbaint_t offset)
 199 {
 200         struct efi_disk_obj *diskobj;
 201         struct efi_device_path_file_path *dp;
 202         int objlen = sizeof(*diskobj) + (sizeof(*dp) * 2);
 203
 204         diskobj = calloc(1, objlen);
 205
 206         /* Fill in object data */
 207         diskobj->parent.protocols[0].guid = &efi_block_io_guid;
 208         diskobj->parent.protocols[0].open = efi_disk_open_block;
 209         diskobj->parent.protocols[1].guid = &efi_guid_device_path;
 210         diskobj->parent.protocols[1].open = efi_disk_open_dp;
 211         diskobj->parent.handle = diskobj;
 212         diskobj->ops = block_io_disk_template;
 213         diskobj->ifname = if_typename;
 214         diskobj->dev_index = dev_index;
 215         diskobj->offset = offset;
 216
 217         /* Fill in EFI IO Media info (for read/write callbacks) */
 218         diskobj->media.removable_media = desc->removable;
 219         diskobj->media.media_present = 1;
 220         diskobj->media.block_size = desc->blksz;
 221         diskobj->media.io_align = desc->blksz;
 222         diskobj->media.last_block = desc->lba;
 223         diskobj->ops.media = &diskobj->media;
 224
 225         /* Fill in device path */
 226         dp = (void*)&diskobj[1];
 227         diskobj->dp = dp;
 228         dp[0].dp.type = DEVICE_PATH_TYPE_MEDIA_DEVICE;
 229         dp[0].dp.sub_type = DEVICE_PATH_SUB_TYPE_FILE_PATH;
 230         dp[0].dp.length = sizeof(*dp);
 231         ascii2unicode(dp[0].str, name);
 232
 233         dp[1].dp.type = DEVICE_PATH_TYPE_END;
 234         dp[1].dp.sub_type = DEVICE_PATH_SUB_TYPE_END;
 235         dp[1].dp.length = sizeof(*dp);
 236
 237         /* Hook up to the device list */
 238         list_add_tail(&diskobj->parent.link, &efi_obj_list);
 239 }
 240
 241 static int efi_disk_create_eltorito(struct blk_desc *desc,
 242                                     const char *if_typename,
 243                                     int diskid)
 244 {
 245         int disks = 0;
 246 #ifdef CONFIG_ISO_PARTITION
 247         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 248         disk_partition_t info;
 249         int part = 1;
 250
 251         if (desc->part_type != PART_TYPE_ISO)
 252                 return 0;
 253
 254         while (!part_get_info(desc, part, &info)) {
 255                 snprintf(devname, sizeof(devname), "%s%d:%d", if_typename,
 256                          diskid, part);
 257                 efi_disk_add_dev(devname, if_typename, desc, diskid,
 258                                  info.start);
 259                 part++;
 260                 disks++;
 261         }
 262 #endif
 263
 264         return disks;
 265 }
 266
 267 /*
 268  * U-Boot doesn't have a list of all online disk devices. So when running our
 269  * EFI payload, we scan through all of the potentially available ones and
 270  * store them in our object pool.
 271  *
 272  * TODO(sjg@chromium.org): Actually with CONFIG_BLK, U-Boot does have this.
 273  * Consider converting the code to look up devices as needed. The EFI device
 274  * could be a child of the UCLASS_BLK block device, perhaps.
 275  *
 276  * This gets called from do_bootefi_exec().
 277  */
 278 int efi_disk_register(void)
 279 {
 280         int disks = 0;
 281 #ifdef CONFIG_BLK
 282         struct udevice *dev;
 283
 284         for (uclass_first_device(UCLASS_BLK, &dev);
 285              dev;
 286              uclass_next_device(&dev)) {
 287                 struct blk_desc *desc = dev_get_uclass_platdata(dev);
 288                 const char *if_typename = dev->driver->name;
 289
 290                 printf("Scanning disk %s...\n", dev->name);
 291                 efi_disk_add_dev(dev->name, if_typename, desc, desc->devnum, 0);
 292                 disks++;
 293
 294                 /*
 295                 * El Torito images show up as block devices in an EFI world,
 296                 * so let's create them here
 297                 */
 298                 disks += efi_disk_create_eltorito(desc, if_typename,
 299                                                   desc->devnum);
 300         }
 301 #else
 302         int i, if_type;
 303
 304         /* Search for all available disk devices */
 305         for (if_type = 0; if_type < IF_TYPE_COUNT; if_type++) {
 306                 const struct blk_driver *cur_drvr;
 307                 const char *if_typename;
 308
 309                 cur_drvr = blk_driver_lookup_type(if_type);
 310                 if (!cur_drvr)
 311                         continue;
 312
 313                 if_typename = cur_drvr->if_typename;
 314                 printf("Scanning disks on %s...\n", if_typename);
 315                 for (i = 0; i < 4; i++) {
 316                         struct blk_desc *desc;
 317                         char devname[32] = { 0 }; /* dp->str is u16[32] long */
 318
 319                         desc = blk_get_devnum_by_type(if_type, i);
 320                         if (!desc)
 321                                 continue;
 322                         if (desc->type == DEV_TYPE_UNKNOWN)
 323                                 continue;
 324
 325                         snprintf(devname, sizeof(devname), "%s%d",
 326                                  if_typename, i);
 327                         efi_disk_add_dev(devname, if_typename, desc, i, 0);
 328                         disks++;
 329
 330                         /*
 331                          * El Torito images show up as block devices
 332                          * in an EFI world, so let's create them here
 333                          */
 334                         disks += efi_disk_create_eltorito(desc, if_typename, i);
 335                 }
 336         }
 337 #endif
 338         printf("Found %d disks\n", disks);
 339
 340         return 0;
 341 }