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