include/blk.h

   1 /*
   2  * (C) Copyright 2000-2004
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #ifndef BLK_H
   9 #define BLK_H
  10
  11 #include <efi.h>
  12
  13 #ifdef CONFIG_SYS_64BIT_LBA
  14 typedef uint64_t lbaint_t;
  15 #define LBAFlength "ll"
  16 #else
  17 typedef ulong lbaint_t;
  18 #define LBAFlength "l"
  19 #endif
  20 #define LBAF "%" LBAFlength "x"
  21 #define LBAFU "%" LBAFlength "u"
  22
  23 /* Interface types: */
  24 enum if_type {
  25         IF_TYPE_UNKNOWN = 0,
  26         IF_TYPE_IDE,
  27         IF_TYPE_SCSI,
  28         IF_TYPE_ATAPI,
  29         IF_TYPE_USB,
  30         IF_TYPE_DOC,
  31         IF_TYPE_MMC,
  32         IF_TYPE_SD,
  33         IF_TYPE_SATA,
  34         IF_TYPE_HOST,
  35         IF_TYPE_SYSTEMACE,
  36         IF_TYPE_NVME,
  37         IF_TYPE_EFI,
  38
  39         IF_TYPE_COUNT,                  /* Number of interface types */
  40 };
  41
  42 #define BLK_VEN_SIZE            40
  43 #define BLK_PRD_SIZE            20
  44 #define BLK_REV_SIZE            8
  45
  46 /*
  47  * Identifies the partition table type (ie. MBR vs GPT GUID) signature
  48  */
  49 enum sig_type {
  50         SIG_TYPE_NONE,
  51         SIG_TYPE_MBR,
  52         SIG_TYPE_GUID,
  53
  54         SIG_TYPE_COUNT                  /* Number of signature types */
  55 };
  56
  57 /*
  58  * With driver model (CONFIG_BLK) this is uclass platform data, accessible
  59  * with dev_get_uclass_platdata(dev)
  60  */
  61 struct blk_desc {
  62         /*
  63          * TODO: With driver model we should be able to use the parent
  64          * device's uclass instead.
  65          */
  66         enum if_type    if_type;        /* type of the interface */
  67         int             devnum;         /* device number */
  68         unsigned char   part_type;      /* partition type */
  69         unsigned char   target;         /* target SCSI ID */
  70         unsigned char   lun;            /* target LUN */
  71         unsigned char   hwpart;         /* HW partition, e.g. for eMMC */
  72         unsigned char   type;           /* device type */
  73         unsigned char   removable;      /* removable device */
  74 #ifdef CONFIG_LBA48
  75         /* device can use 48bit addr (ATA/ATAPI v7) */
  76         unsigned char   lba48;
  77 #endif
  78         lbaint_t        lba;            /* number of blocks */
  79         unsigned long   blksz;          /* block size */
  80         int             log2blksz;      /* for convenience: log2(blksz) */
  81         char            vendor[BLK_VEN_SIZE + 1]; /* device vendor string */
  82         char            product[BLK_PRD_SIZE + 1]; /* device product number */
  83         char            revision[BLK_REV_SIZE + 1]; /* firmware revision */
  84         enum sig_type   sig_type;       /* Partition table signature type */
  85         union {
  86                 uint32_t mbr_sig;       /* MBR integer signature */
  87                 efi_guid_t guid_sig;    /* GPT GUID Signature */
  88         };
  89 #if CONFIG_IS_ENABLED(BLK)
  90         /*
  91          * For now we have a few functions which take struct blk_desc as a
  92          * parameter. This field allows them to look up the associated
  93          * device. Once these functions are removed we can drop this field.
  94          */
  95         struct udevice *bdev;
  96 #else
  97         unsigned long   (*block_read)(struct blk_desc *block_dev,
  98                                       lbaint_t start,
  99                                       lbaint_t blkcnt,
 100                                       void *buffer);
 101         unsigned long   (*block_write)(struct blk_desc *block_dev,
 102                                        lbaint_t start,
 103                                        lbaint_t blkcnt,
 104                                        const void *buffer);
 105         unsigned long   (*block_erase)(struct blk_desc *block_dev,
 106                                        lbaint_t start,
 107                                        lbaint_t blkcnt);
 108         void            *priv;          /* driver private struct pointer */
 109 #endif
 110 };
 111
 112 #define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz))
 113 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
 114         (PAD_SIZE(size, blk_desc->blksz))
 115
 116 #ifdef CONFIG_BLOCK_CACHE
 117 /**
 118  * blkcache_read() - attempt to read a set of blocks from cache
 119  *
 120  * @param iftype - IF_TYPE_x for type of device
 121  * @param dev - device index of particular type
 122  * @param start - starting block number
 123  * @param blkcnt - number of blocks to read
 124  * @param blksz - size in bytes of each block
 125  * @param buf - buffer to contain cached data
 126  *
 127  * @return - '1' if block returned from cache, '0' otherwise.
 128  */
 129 int blkcache_read(int iftype, int dev,
 130                   lbaint_t start, lbaint_t blkcnt,
 131                   unsigned long blksz, void *buffer);
 132
 133 /**
 134  * blkcache_fill() - make data read from a block device available
 135  * to the block cache
 136  *
 137  * @param iftype - IF_TYPE_x for type of device
 138  * @param dev - device index of particular type
 139  * @param start - starting block number
 140  * @param blkcnt - number of blocks available
 141  * @param blksz - size in bytes of each block
 142  * @param buf - buffer containing data to cache
 143  *
 144  */
 145 void blkcache_fill(int iftype, int dev,
 146                    lbaint_t start, lbaint_t blkcnt,
 147                    unsigned long blksz, void const *buffer);
 148
 149 /**
 150  * blkcache_invalidate() - discard the cache for a set of blocks
 151  * because of a write or device (re)initialization.
 152  *
 153  * @param iftype - IF_TYPE_x for type of device
 154  * @param dev - device index of particular type
 155  */
 156 void blkcache_invalidate(int iftype, int dev);
 157
 158 /**
 159  * blkcache_configure() - configure block cache
 160  *
 161  * @param blocks - maximum blocks per entry
 162  * @param entries - maximum entries in cache
 163  */
 164 void blkcache_configure(unsigned blocks, unsigned entries);
 165
 166 /*
 167  * statistics of the block cache
 168  */
 169 struct block_cache_stats {
 170         unsigned hits;
 171         unsigned misses;
 172         unsigned entries; /* current entry count */
 173         unsigned max_blocks_per_entry;
 174         unsigned max_entries;
 175 };
 176
 177 /**
 178  * get_blkcache_stats() - return statistics and reset
 179  *
 180  * @param stats - statistics are copied here
 181  */
 182 void blkcache_stats(struct block_cache_stats *stats);
 183
 184 #else
 185
 186 static inline int blkcache_read(int iftype, int dev,
 187                                 lbaint_t start, lbaint_t blkcnt,
 188                                 unsigned long blksz, void *buffer)
 189 {
 190         return 0;
 191 }
 192
 193 static inline void blkcache_fill(int iftype, int dev,
 194                                  lbaint_t start, lbaint_t blkcnt,
 195                                  unsigned long blksz, void const *buffer) {}
 196
 197 static inline void blkcache_invalidate(int iftype, int dev) {}
 198
 199 #endif
 200
 201 #if CONFIG_IS_ENABLED(BLK)
 202 struct udevice;
 203
 204 /* Operations on block devices */
 205 struct blk_ops {
 206         /**
 207          * read() - read from a block device
 208          *
 209          * @dev:        Device to read from
 210          * @start:      Start block number to read (0=first)
 211          * @blkcnt:     Number of blocks to read
 212          * @buffer:     Destination buffer for data read
 213          * @return number of blocks read, or -ve error number (see the
 214          * IS_ERR_VALUE() macro
 215          */
 216         unsigned long (*read)(struct udevice *dev, lbaint_t start,
 217                               lbaint_t blkcnt, void *buffer);
 218
 219         /**
 220          * write() - write to a block device
 221          *
 222          * @dev:        Device to write to
 223          * @start:      Start block number to write (0=first)
 224          * @blkcnt:     Number of blocks to write
 225          * @buffer:     Source buffer for data to write
 226          * @return number of blocks written, or -ve error number (see the
 227          * IS_ERR_VALUE() macro
 228          */
 229         unsigned long (*write)(struct udevice *dev, lbaint_t start,
 230                                lbaint_t blkcnt, const void *buffer);
 231
 232         /**
 233          * erase() - erase a section of a block device
 234          *
 235          * @dev:        Device to (partially) erase
 236          * @start:      Start block number to erase (0=first)
 237          * @blkcnt:     Number of blocks to erase
 238          * @return number of blocks erased, or -ve error number (see the
 239          * IS_ERR_VALUE() macro
 240          */
 241         unsigned long (*erase)(struct udevice *dev, lbaint_t start,
 242                                lbaint_t blkcnt);
 243
 244         /**
 245          * select_hwpart() - select a particular hardware partition
 246          *
 247          * Some devices (e.g. MMC) can support partitioning at the hardware
 248          * level. This is quite separate from the normal idea of
 249          * software-based partitions. MMC hardware partitions must be
 250          * explicitly selected. Once selected only the region of the device
 251          * covered by that partition is accessible.
 252          *
 253          * The MMC standard provides for two boot partitions (numbered 1 and 2),
 254          * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
 255          *
 256          * @desc:       Block device to update
 257          * @hwpart:     Hardware partition number to select. 0 means the raw
 258          *              device, 1 is the first partition, 2 is the second, etc.
 259          * @return 0 if OK, -ve on error
 260          */
 261         int (*select_hwpart)(struct udevice *dev, int hwpart);
 262 };
 263
 264 #define blk_get_ops(dev)        ((struct blk_ops *)(dev)->driver->ops)
 265
 266 /*
 267  * These functions should take struct udevice instead of struct blk_desc,
 268  * but this is convenient for migration to driver model. Add a 'd' prefix
 269  * to the function operations, so that blk_read(), etc. can be reserved for
 270  * functions with the correct arguments.
 271  */
 272 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
 273                         lbaint_t blkcnt, void *buffer);
 274 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
 275                          lbaint_t blkcnt, const void *buffer);
 276 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
 277                          lbaint_t blkcnt);
 278
 279 /**
 280  * blk_find_device() - Find a block device
 281  *
 282  * This function does not activate the device. The device will be returned
 283  * whether or not it is activated.
 284  *
 285  * @if_type:    Interface type (enum if_type_t)
 286  * @devnum:     Device number (specific to each interface type)
 287  * @devp:       the device, if found
 288  * @return 0 if found, -ENODEV if no device found, or other -ve error value
 289  */
 290 int blk_find_device(int if_type, int devnum, struct udevice **devp);
 291
 292 /**
 293  * blk_get_device() - Find and probe a block device ready for use
 294  *
 295  * @if_type:    Interface type (enum if_type_t)
 296  * @devnum:     Device number (specific to each interface type)
 297  * @devp:       the device, if found
 298  * @return 0 if found, -ENODEV if no device found, or other -ve error value
 299  */
 300 int blk_get_device(int if_type, int devnum, struct udevice **devp);
 301
 302 /**
 303  * blk_first_device() - Find the first device for a given interface
 304  *
 305  * The device is probed ready for use
 306  *
 307  * @devnum:     Device number (specific to each interface type)
 308  * @devp:       the device, if found
 309  * @return 0 if found, -ENODEV if no device, or other -ve error value
 310  */
 311 int blk_first_device(int if_type, struct udevice **devp);
 312
 313 /**
 314  * blk_next_device() - Find the next device for a given interface
 315  *
 316  * This can be called repeatedly after blk_first_device() to iterate through
 317  * all devices of the given interface type.
 318  *
 319  * The device is probed ready for use
 320  *
 321  * @devp:       On entry, the previous device returned. On exit, the next
 322  *              device, if found
 323  * @return 0 if found, -ENODEV if no device, or other -ve error value
 324  */
 325 int blk_next_device(struct udevice **devp);
 326
 327 /**
 328  * blk_create_device() - Create a new block device
 329  *
 330  * @parent:     Parent of the new device
 331  * @drv_name:   Driver name to use for the block device
 332  * @name:       Name for the device
 333  * @if_type:    Interface type (enum if_type_t)
 334  * @devnum:     Device number, specific to the interface type, or -1 to
 335  *              allocate the next available number
 336  * @blksz:      Block size of the device in bytes (typically 512)
 337  * @lba:        Total number of blocks of the device
 338  * @devp:       the new device (which has not been probed)
 339  */
 340 int blk_create_device(struct udevice *parent, const char *drv_name,
 341                       const char *name, int if_type, int devnum, int blksz,
 342                       lbaint_t lba, struct udevice **devp);
 343
 344 /**
 345  * blk_create_devicef() - Create a new named block device
 346  *
 347  * @parent:     Parent of the new device
 348  * @drv_name:   Driver name to use for the block device
 349  * @name:       Name for the device (parent name is prepended)
 350  * @if_type:    Interface type (enum if_type_t)
 351  * @devnum:     Device number, specific to the interface type, or -1 to
 352  *              allocate the next available number
 353  * @blksz:      Block size of the device in bytes (typically 512)
 354  * @lba:        Total number of blocks of the device
 355  * @devp:       the new device (which has not been probed)
 356  */
 357 int blk_create_devicef(struct udevice *parent, const char *drv_name,
 358                        const char *name, int if_type, int devnum, int blksz,
 359                        lbaint_t lba, struct udevice **devp);
 360
 361 /**
 362  * blk_prepare_device() - Prepare a block device for use
 363  *
 364  * This reads partition information from the device if supported.
 365  *
 366  * @dev:        Device to prepare
 367  * @return 0 if ok, -ve on error
 368  */
 369 int blk_prepare_device(struct udevice *dev);
 370
 371 /**
 372  * blk_unbind_all() - Unbind all device of the given interface type
 373  *
 374  * The devices are removed and then unbound.
 375  *
 376  * @if_type:    Interface type to unbind
 377  * @return 0 if OK, -ve on error
 378  */
 379 int blk_unbind_all(int if_type);
 380
 381 /**
 382  * blk_find_max_devnum() - find the maximum device number for an interface type
 383  *
 384  * Finds the last allocated device number for an interface type @if_type. The
 385  * next number is safe to use for a newly allocated device.
 386  *
 387  * @if_type:    Interface type to scan
 388  * @return maximum device number found, or -ENODEV if none, or other -ve on
 389  * error
 390  */
 391 int blk_find_max_devnum(enum if_type if_type);
 392
 393 /**
 394  * blk_select_hwpart() - select a hardware partition
 395  *
 396  * Select a hardware partition if the device supports it (typically MMC does)
 397  *
 398  * @dev:        Device to update
 399  * @hwpart:     Partition number to select
 400  * @return 0 if OK, -ve on error
 401  */
 402 int blk_select_hwpart(struct udevice *dev, int hwpart);
 403
 404 /**
 405  * blk_get_from_parent() - obtain a block device by looking up its parent
 406  *
 407  * All devices with
 408  */
 409 int blk_get_from_parent(struct udevice *parent, struct udevice **devp);
 410
 411 #else
 412 #include <errno.h>
 413 /*
 414  * These functions should take struct udevice instead of struct blk_desc,
 415  * but this is convenient for migration to driver model. Add a 'd' prefix
 416  * to the function operations, so that blk_read(), etc. can be reserved for
 417  * functions with the correct arguments.
 418  */
 419 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
 420                               lbaint_t blkcnt, void *buffer)
 421 {
 422         ulong blks_read;
 423         if (blkcache_read(block_dev->if_type, block_dev->devnum,
 424                           start, blkcnt, block_dev->blksz, buffer))
 425                 return blkcnt;
 426
 427         /*
 428          * We could check if block_read is NULL and return -ENOSYS. But this
 429          * bloats the code slightly (cause some board to fail to build), and
 430          * it would be an error to try an operation that does not exist.
 431          */
 432         blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
 433         if (blks_read == blkcnt)
 434                 blkcache_fill(block_dev->if_type, block_dev->devnum,
 435                               start, blkcnt, block_dev->blksz, buffer);
 436
 437         return blks_read;
 438 }
 439
 440 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
 441                                lbaint_t blkcnt, const void *buffer)
 442 {
 443         blkcache_invalidate(block_dev->if_type, block_dev->devnum);
 444         return block_dev->block_write(block_dev, start, blkcnt, buffer);
 445 }
 446
 447 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
 448                                lbaint_t blkcnt)
 449 {
 450         blkcache_invalidate(block_dev->if_type, block_dev->devnum);
 451         return block_dev->block_erase(block_dev, start, blkcnt);
 452 }
 453
 454 /**
 455  * struct blk_driver - Driver for block interface types
 456  *
 457  * This provides access to the block devices for each interface type. One
 458  * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
 459  * type that is to be supported.
 460  *
 461  * @if_typename:        Interface type name
 462  * @if_type:            Interface type
 463  * @max_devs:           Maximum number of devices supported
 464  * @desc:               Pointer to list of devices for this interface type,
 465  *                      or NULL to use @get_dev() instead
 466  */
 467 struct blk_driver {
 468         const char *if_typename;
 469         enum if_type if_type;
 470         int max_devs;
 471         struct blk_desc *desc;
 472         /**
 473          * get_dev() - get a pointer to a block device given its number
 474          *
 475          * Each interface allocates its own devices and typically
 476          * struct blk_desc is contained with the interface's data structure.
 477          * There is no global numbering for block devices. This method allows
 478          * the device for an interface type to be obtained when @desc is NULL.
 479          *
 480          * @devnum:     Device number (0 for first device on that interface,
 481          *              1 for second, etc.
 482          * @descp:      Returns pointer to the block device on success
 483          * @return 0 if OK, -ve on error
 484          */
 485         int (*get_dev)(int devnum, struct blk_desc **descp);
 486
 487         /**
 488          * select_hwpart() - Select a hardware partition
 489          *
 490          * Some devices (e.g. MMC) can support partitioning at the hardware
 491          * level. This is quite separate from the normal idea of
 492          * software-based partitions. MMC hardware partitions must be
 493          * explicitly selected. Once selected only the region of the device
 494          * covered by that partition is accessible.
 495          *
 496          * The MMC standard provides for two boot partitions (numbered 1 and 2),
 497          * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
 498          * Partition 0 is the main user-data partition.
 499          *
 500          * @desc:       Block device descriptor
 501          * @hwpart:     Hardware partition number to select. 0 means the main
 502          *              user-data partition, 1 is the first partition, 2 is
 503          *              the second, etc.
 504          * @return 0 if OK, other value for an error
 505          */
 506         int (*select_hwpart)(struct blk_desc *desc, int hwpart);
 507 };
 508
 509 /*
 510  * Declare a new U-Boot legacy block driver. New drivers should use driver
 511  * model (UCLASS_BLK).
 512  */
 513 #define U_BOOT_LEGACY_BLK(__name)                                       \
 514         ll_entry_declare(struct blk_driver, __name, blk_driver)
 515
 516 struct blk_driver *blk_driver_lookup_type(int if_type);
 517
 518 #endif /* !CONFIG_BLK */
 519
 520 /**
 521  * blk_get_devnum_by_typename() - Get a block device by type and number
 522  *
 523  * This looks through the available block devices of the given type, returning
 524  * the one with the given @devnum.
 525  *
 526  * @if_type:    Block device type
 527  * @devnum:     Device number
 528  * @return point to block device descriptor, or NULL if not found
 529  */
 530 struct blk_desc *blk_get_devnum_by_type(enum if_type if_type, int devnum);
 531
 532 /**
 533  * blk_get_devnum_by_type() - Get a block device by type name, and number
 534  *
 535  * This looks up the block device type based on @if_typename, then calls
 536  * blk_get_devnum_by_type().
 537  *
 538  * @if_typename:        Block device type name
 539  * @devnum:             Device number
 540  * @return point to block device descriptor, or NULL if not found
 541  */
 542 struct blk_desc *blk_get_devnum_by_typename(const char *if_typename,
 543                                             int devnum);
 544
 545 /**
 546  * blk_dselect_hwpart() - select a hardware partition
 547  *
 548  * This selects a hardware partition (such as is supported by MMC). The block
 549  * device size may change as this effectively points the block device to a
 550  * partition at the hardware level. See the select_hwpart() method above.
 551  *
 552  * @desc:       Block device descriptor for the device to select
 553  * @hwpart:     Partition number to select
 554  * @return 0 if OK, -ve on error
 555  */
 556 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
 557
 558 /**
 559  * blk_list_part() - list the partitions for block devices of a given type
 560  *
 561  * This looks up the partition type for each block device of type @if_type,
 562  * then displays a list of partitions.
 563  *
 564  * @if_type:    Block device type
 565  * @return 0 if OK, -ENODEV if there is none of that type
 566  */
 567 int blk_list_part(enum if_type if_type);
 568
 569 /**
 570  * blk_list_devices() - list the block devices of a given type
 571  *
 572  * This lists each block device of the type @if_type, showing the capacity
 573  * as well as type-specific information.
 574  *
 575  * @if_type:    Block device type
 576  */
 577 void blk_list_devices(enum if_type if_type);
 578
 579 /**
 580  * blk_show_device() - show information about a given block device
 581  *
 582  * This shows the block device capacity as well as type-specific information.
 583  *
 584  * @if_type:    Block device type
 585  * @devnum:     Device number
 586  * @return 0 if OK, -ENODEV for invalid device number
 587  */
 588 int blk_show_device(enum if_type if_type, int devnum);
 589
 590 /**
 591  * blk_print_device_num() - show information about a given block device
 592  *
 593  * This is similar to blk_show_device() but returns an error if the block
 594  * device type is unknown.
 595  *
 596  * @if_type:    Block device type
 597  * @devnum:     Device number
 598  * @return 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
 599  * device is not connected
 600  */
 601 int blk_print_device_num(enum if_type if_type, int devnum);
 602
 603 /**
 604  * blk_print_part_devnum() - print the partition information for a device
 605  *
 606  * @if_type:    Block device type
 607  * @devnum:     Device number
 608  * @return 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
 609  * the interface type is not supported, other -ve on other error
 610  */
 611 int blk_print_part_devnum(enum if_type if_type, int devnum);
 612
 613 /**
 614  * blk_read_devnum() - read blocks from a device
 615  *
 616  * @if_type:    Block device type
 617  * @devnum:     Device number
 618  * @blkcnt:     Number of blocks to read
 619  * @buffer:     Address to write data to
 620  * @return number of blocks read, or -ve error number on error
 621  */
 622 ulong blk_read_devnum(enum if_type if_type, int devnum, lbaint_t start,
 623                       lbaint_t blkcnt, void *buffer);
 624
 625 /**
 626  * blk_write_devnum() - write blocks to a device
 627  *
 628  * @if_type:    Block device type
 629  * @devnum:     Device number
 630  * @blkcnt:     Number of blocks to write
 631  * @buffer:     Address to read data from
 632  * @return number of blocks written, or -ve error number on error
 633  */
 634 ulong blk_write_devnum(enum if_type if_type, int devnum, lbaint_t start,
 635                        lbaint_t blkcnt, const void *buffer);
 636
 637 /**
 638  * blk_select_hwpart_devnum() - select a hardware partition
 639  *
 640  * This is similar to blk_dselect_hwpart() but it looks up the interface and
 641  * device number.
 642  *
 643  * @if_type:    Block device type
 644  * @devnum:     Device number
 645  * @hwpart:     Partition number to select
 646  * @return 0 if OK, -ve on error
 647  */
 648 int blk_select_hwpart_devnum(enum if_type if_type, int devnum, int hwpart);
 649
 650 /**
 651  * blk_get_if_type_name() - Get the name of an interface type
 652  *
 653  * @if_type: Interface type to check
 654  * @return name of interface, or NULL if none
 655  */
 656 const char *blk_get_if_type_name(enum if_type if_type);
 657
 658 /**
 659  * blk_common_cmd() - handle common commands with block devices
 660  *
 661  * @args: Number of arguments to the command (argv[0] is the command itself)
 662  * @argv: Command arguments
 663  * @if_type: Interface type
 664  * @cur_devnump: Current device number for this interface type
 665  * @return 0 if OK, CMD_RET_ERROR on error
 666  */
 667 int blk_common_cmd(int argc, char * const argv[], enum if_type if_type,
 668                    int *cur_devnump);
 669
 670 #endif