include/blk.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * (C) Copyright 2000-2004
   4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   5  */
   6
   7 #ifndef BLK_H
   8 #define BLK_H
   9
  10 #include <efi.h>
  11
  12 #ifdef CONFIG_SYS_64BIT_LBA
  13 typedef uint64_t lbaint_t;
  14 #define LBAFlength "ll"
  15 #else
  16 typedef ulong lbaint_t;
  17 #define LBAFlength "l"
  18 #endif
  19 #define LBAF "%" LBAFlength "x"
  20 #define LBAFU "%" LBAFlength "u"
  21
  22 /* Interface types: */
  23 enum if_type {
  24         IF_TYPE_UNKNOWN = 0,
  25         IF_TYPE_IDE,
  26         IF_TYPE_SCSI,
  27         IF_TYPE_ATAPI,
  28         IF_TYPE_USB,
  29         IF_TYPE_DOC,
  30         IF_TYPE_MMC,
  31         IF_TYPE_SD,
  32         IF_TYPE_SATA,
  33         IF_TYPE_HOST,
  34         IF_TYPE_NVME,
  35         IF_TYPE_EFI,
  36         IF_TYPE_VIRTIO,
  37
  38         IF_TYPE_COUNT,                  /* Number of interface types */
  39 };
  40
  41 #define BLK_VEN_SIZE            40
  42 #define BLK_PRD_SIZE            20
  43 #define BLK_REV_SIZE            8
  44
  45 /*
  46  * Identifies the partition table type (ie. MBR vs GPT GUID) signature
  47  */
  48 enum sig_type {
  49         SIG_TYPE_NONE,
  50         SIG_TYPE_MBR,
  51         SIG_TYPE_GUID,
  52
  53         SIG_TYPE_COUNT                  /* Number of signature types */
  54 };
  55
  56 /*
  57  * With driver model (CONFIG_BLK) this is uclass platform data, accessible
  58  * with dev_get_uclass_platdata(dev)
  59  */
  60 struct blk_desc {
  61         /*
  62          * TODO: With driver model we should be able to use the parent
  63          * device's uclass instead.
  64          */
  65         enum if_type    if_type;        /* type of the interface */
  66         int             devnum;         /* device number */
  67         unsigned char   part_type;      /* partition type */
  68         unsigned char   target;         /* target SCSI ID */
  69         unsigned char   lun;            /* target LUN */
  70         unsigned char   hwpart;         /* HW partition, e.g. for eMMC */
  71         unsigned char   type;           /* device type */
  72         unsigned char   removable;      /* removable device */
  73 #ifdef CONFIG_LBA48
  74         /* device can use 48bit addr (ATA/ATAPI v7) */
  75         unsigned char   lba48;
  76 #endif
  77         lbaint_t        lba;            /* number of blocks */
  78         unsigned long   blksz;          /* block size */
  79         int             log2blksz;      /* for convenience: log2(blksz) */
  80         char            vendor[BLK_VEN_SIZE + 1]; /* device vendor string */
  81         char            product[BLK_PRD_SIZE + 1]; /* device product number */
  82         char            revision[BLK_REV_SIZE + 1]; /* firmware revision */
  83         enum sig_type   sig_type;       /* Partition table signature type */
  84         union {
  85                 uint32_t mbr_sig;       /* MBR integer signature */
  86                 efi_guid_t guid_sig;    /* GPT GUID Signature */
  87         };
  88 #if CONFIG_IS_ENABLED(BLK)
  89         /*
  90          * For now we have a few functions which take struct blk_desc as a
  91          * parameter. This field allows them to look up the associated
  92          * device. Once these functions are removed we can drop this field.
  93          */
  94         struct udevice *bdev;
  95 #else
  96         unsigned long   (*block_read)(struct blk_desc *block_dev,
  97                                       lbaint_t start,
  98                                       lbaint_t blkcnt,
  99                                       void *buffer);
 100         unsigned long   (*block_write)(struct blk_desc *block_dev,
 101                                        lbaint_t start,
 102                                        lbaint_t blkcnt,
 103                                        const void *buffer);
 104         unsigned long   (*block_erase)(struct blk_desc *block_dev,
 105                                        lbaint_t start,
 106                                        lbaint_t blkcnt);
 107         void            *priv;          /* driver private struct pointer */
 108 #endif
 109 };
 110
 111 #define BLOCK_CNT(size, blk_desc) (PAD_COUNT(size, blk_desc->blksz))
 112 #define PAD_TO_BLOCKSIZE(size, blk_desc) \
 113         (PAD_SIZE(size, blk_desc->blksz))
 114
 115 #if CONFIG_IS_ENABLED(BLOCK_CACHE)
 116
 117 /**
 118  * blkcache_init() - initialize the block cache list pointers
 119  */
 120 int blkcache_init(void);
 121
 122 /**
 123  * blkcache_read() - attempt to read a set of blocks from cache
 124  *
 125  * @param iftype - IF_TYPE_x for type of device
 126  * @param dev - device index of particular type
 127  * @param start - starting block number
 128  * @param blkcnt - number of blocks to read
 129  * @param blksz - size in bytes of each block
 130  * @param buf - buffer to contain cached data
 131  *
 132  * @return - 1 if block returned from cache, 0 otherwise.
 133  */
 134 int blkcache_read(int iftype, int dev,
 135                   lbaint_t start, lbaint_t blkcnt,
 136                   unsigned long blksz, void *buffer);
 137
 138 /**
 139  * blkcache_fill() - make data read from a block device available
 140  * to the block cache
 141  *
 142  * @param iftype - IF_TYPE_x for type of device
 143  * @param dev - device index of particular type
 144  * @param start - starting block number
 145  * @param blkcnt - number of blocks available
 146  * @param blksz - size in bytes of each block
 147  * @param buf - buffer containing data to cache
 148  *
 149  */
 150 void blkcache_fill(int iftype, int dev,
 151                    lbaint_t start, lbaint_t blkcnt,
 152                    unsigned long blksz, void const *buffer);
 153
 154 /**
 155  * blkcache_invalidate() - discard the cache for a set of blocks
 156  * because of a write or device (re)initialization.
 157  *
 158  * @param iftype - IF_TYPE_x for type of device
 159  * @param dev - device index of particular type
 160  */
 161 void blkcache_invalidate(int iftype, int dev);
 162
 163 /**
 164  * blkcache_configure() - configure block cache
 165  *
 166  * @param blocks - maximum blocks per entry
 167  * @param entries - maximum entries in cache
 168  */
 169 void blkcache_configure(unsigned blocks, unsigned entries);
 170
 171 /*
 172  * statistics of the block cache
 173  */
 174 struct block_cache_stats {
 175         unsigned hits;
 176         unsigned misses;
 177         unsigned entries; /* current entry count */
 178         unsigned max_blocks_per_entry;
 179         unsigned max_entries;
 180 };
 181
 182 /**
 183  * get_blkcache_stats() - return statistics and reset
 184  *
 185  * @param stats - statistics are copied here
 186  */
 187 void blkcache_stats(struct block_cache_stats *stats);
 188
 189 #else
 190
 191 static inline int blkcache_read(int iftype, int dev,
 192                                 lbaint_t start, lbaint_t blkcnt,
 193                                 unsigned long blksz, void *buffer)
 194 {
 195         return 0;
 196 }
 197
 198 static inline void blkcache_fill(int iftype, int dev,
 199                                  lbaint_t start, lbaint_t blkcnt,
 200                                  unsigned long blksz, void const *buffer) {}
 201
 202 static inline void blkcache_invalidate(int iftype, int dev) {}
 203
 204 #endif
 205
 206 #if CONFIG_IS_ENABLED(BLK)
 207 struct udevice;
 208
 209 /* Operations on block devices */
 210 struct blk_ops {
 211         /**
 212          * read() - read from a block device
 213          *
 214          * @dev:        Device to read from
 215          * @start:      Start block number to read (0=first)
 216          * @blkcnt:     Number of blocks to read
 217          * @buffer:     Destination buffer for data read
 218          * @return number of blocks read, or -ve error number (see the
 219          * IS_ERR_VALUE() macro
 220          */
 221         unsigned long (*read)(struct udevice *dev, lbaint_t start,
 222                               lbaint_t blkcnt, void *buffer);
 223
 224         /**
 225          * write() - write to a block device
 226          *
 227          * @dev:        Device to write to
 228          * @start:      Start block number to write (0=first)
 229          * @blkcnt:     Number of blocks to write
 230          * @buffer:     Source buffer for data to write
 231          * @return number of blocks written, or -ve error number (see the
 232          * IS_ERR_VALUE() macro
 233          */
 234         unsigned long (*write)(struct udevice *dev, lbaint_t start,
 235                                lbaint_t blkcnt, const void *buffer);
 236
 237         /**
 238          * erase() - erase a section of a block device
 239          *
 240          * @dev:        Device to (partially) erase
 241          * @start:      Start block number to erase (0=first)
 242          * @blkcnt:     Number of blocks to erase
 243          * @return number of blocks erased, or -ve error number (see the
 244          * IS_ERR_VALUE() macro
 245          */
 246         unsigned long (*erase)(struct udevice *dev, lbaint_t start,
 247                                lbaint_t blkcnt);
 248
 249         /**
 250          * select_hwpart() - select a particular hardware partition
 251          *
 252          * Some devices (e.g. MMC) can support partitioning at the hardware
 253          * level. This is quite separate from the normal idea of
 254          * software-based partitions. MMC hardware partitions must be
 255          * explicitly selected. Once selected only the region of the device
 256          * covered by that partition is accessible.
 257          *
 258          * The MMC standard provides for two boot partitions (numbered 1 and 2),
 259          * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
 260          *
 261          * @desc:       Block device to update
 262          * @hwpart:     Hardware partition number to select. 0 means the raw
 263          *              device, 1 is the first partition, 2 is the second, etc.
 264          * @return 0 if OK, -ve on error
 265          */
 266         int (*select_hwpart)(struct udevice *dev, int hwpart);
 267 };
 268
 269 #define blk_get_ops(dev)        ((struct blk_ops *)(dev)->driver->ops)
 270
 271 /*
 272  * These functions should take struct udevice instead of struct blk_desc,
 273  * but this is convenient for migration to driver model. Add a 'd' prefix
 274  * to the function operations, so that blk_read(), etc. can be reserved for
 275  * functions with the correct arguments.
 276  */
 277 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
 278                         lbaint_t blkcnt, void *buffer);
 279 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
 280                          lbaint_t blkcnt, const void *buffer);
 281 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
 282                          lbaint_t blkcnt);
 283
 284 /**
 285  * blk_find_device() - Find a block device
 286  *
 287  * This function does not activate the device. The device will be returned
 288  * whether or not it is activated.
 289  *
 290  * @if_type:    Interface type (enum if_type_t)
 291  * @devnum:     Device number (specific to each interface type)
 292  * @devp:       the device, if found
 293  * @return 0 if found, -ENODEV if no device found, or other -ve error value
 294  */
 295 int blk_find_device(int if_type, int devnum, struct udevice **devp);
 296
 297 /**
 298  * blk_get_device() - Find and probe a block device ready for use
 299  *
 300  * @if_type:    Interface type (enum if_type_t)
 301  * @devnum:     Device number (specific to each interface type)
 302  * @devp:       the device, if found
 303  * @return 0 if found, -ENODEV if no device found, or other -ve error value
 304  */
 305 int blk_get_device(int if_type, int devnum, struct udevice **devp);
 306
 307 /**
 308  * blk_first_device() - Find the first device for a given interface
 309  *
 310  * The device is probed ready for use
 311  *
 312  * @devnum:     Device number (specific to each interface type)
 313  * @devp:       the device, if found
 314  * @return 0 if found, -ENODEV if no device, or other -ve error value
 315  */
 316 int blk_first_device(int if_type, struct udevice **devp);
 317
 318 /**
 319  * blk_next_device() - Find the next device for a given interface
 320  *
 321  * This can be called repeatedly after blk_first_device() to iterate through
 322  * all devices of the given interface type.
 323  *
 324  * The device is probed ready for use
 325  *
 326  * @devp:       On entry, the previous device returned. On exit, the next
 327  *              device, if found
 328  * @return 0 if found, -ENODEV if no device, or other -ve error value
 329  */
 330 int blk_next_device(struct udevice **devp);
 331
 332 /**
 333  * blk_create_device() - Create a new block device
 334  *
 335  * @parent:     Parent of the new device
 336  * @drv_name:   Driver name to use for the block device
 337  * @name:       Name for the device
 338  * @if_type:    Interface type (enum if_type_t)
 339  * @devnum:     Device number, specific to the interface type, or -1 to
 340  *              allocate the next available number
 341  * @blksz:      Block size of the device in bytes (typically 512)
 342  * @lba:        Total number of blocks of the device
 343  * @devp:       the new device (which has not been probed)
 344  */
 345 int blk_create_device(struct udevice *parent, const char *drv_name,
 346                       const char *name, int if_type, int devnum, int blksz,
 347                       lbaint_t lba, struct udevice **devp);
 348
 349 /**
 350  * blk_create_devicef() - Create a new named block device
 351  *
 352  * @parent:     Parent of the new device
 353  * @drv_name:   Driver name to use for the block device
 354  * @name:       Name for the device (parent name is prepended)
 355  * @if_type:    Interface type (enum if_type_t)
 356  * @devnum:     Device number, specific to the interface type, or -1 to
 357  *              allocate the next available number
 358  * @blksz:      Block size of the device in bytes (typically 512)
 359  * @lba:        Total number of blocks of the device
 360  * @devp:       the new device (which has not been probed)
 361  */
 362 int blk_create_devicef(struct udevice *parent, const char *drv_name,
 363                        const char *name, int if_type, int devnum, int blksz,
 364                        lbaint_t lba, struct udevice **devp);
 365
 366 /**
 367  * blk_unbind_all() - Unbind all device of the given interface type
 368  *
 369  * The devices are removed and then unbound.
 370  *
 371  * @if_type:    Interface type to unbind
 372  * @return 0 if OK, -ve on error
 373  */
 374 int blk_unbind_all(int if_type);
 375
 376 /**
 377  * blk_find_max_devnum() - find the maximum device number for an interface type
 378  *
 379  * Finds the last allocated device number for an interface type @if_type. The
 380  * next number is safe to use for a newly allocated device.
 381  *
 382  * @if_type:    Interface type to scan
 383  * @return maximum device number found, or -ENODEV if none, or other -ve on
 384  * error
 385  */
 386 int blk_find_max_devnum(enum if_type if_type);
 387
 388 /**
 389  * blk_next_free_devnum() - get the next device number for an interface type
 390  *
 391  * Finds the next number that is safe to use for a newly allocated device for
 392  * an interface type @if_type.
 393  *
 394  * @if_type:    Interface type to scan
 395  * @return next device number safe to use, or -ve on error
 396  */
 397 int blk_next_free_devnum(enum if_type if_type);
 398
 399 /**
 400  * blk_select_hwpart() - select a hardware partition
 401  *
 402  * Select a hardware partition if the device supports it (typically MMC does)
 403  *
 404  * @dev:        Device to update
 405  * @hwpart:     Partition number to select
 406  * @return 0 if OK, -ve on error
 407  */
 408 int blk_select_hwpart(struct udevice *dev, int hwpart);
 409
 410 /**
 411  * blk_get_from_parent() - obtain a block device by looking up its parent
 412  *
 413  * All devices with
 414  */
 415 int blk_get_from_parent(struct udevice *parent, struct udevice **devp);
 416
 417 /**
 418  * blk_get_by_device() - Get the block device descriptor for the given device
 419  * @dev:        Instance of a storage device
 420  *
 421  * Return: With block device descriptor on success , NULL if there is no such
 422  *         block device.
 423  */
 424 struct blk_desc *blk_get_by_device(struct udevice *dev);
 425
 426 #else
 427 #include <errno.h>
 428 /*
 429  * These functions should take struct udevice instead of struct blk_desc,
 430  * but this is convenient for migration to driver model. Add a 'd' prefix
 431  * to the function operations, so that blk_read(), etc. can be reserved for
 432  * functions with the correct arguments.
 433  */
 434 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
 435                               lbaint_t blkcnt, void *buffer)
 436 {
 437         ulong blks_read;
 438         if (blkcache_read(block_dev->if_type, block_dev->devnum,
 439                           start, blkcnt, block_dev->blksz, buffer))
 440                 return blkcnt;
 441
 442         /*
 443          * We could check if block_read is NULL and return -ENOSYS. But this
 444          * bloats the code slightly (cause some board to fail to build), and
 445          * it would be an error to try an operation that does not exist.
 446          */
 447         blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
 448         if (blks_read == blkcnt)
 449                 blkcache_fill(block_dev->if_type, block_dev->devnum,
 450                               start, blkcnt, block_dev->blksz, buffer);
 451
 452         return blks_read;
 453 }
 454
 455 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
 456                                lbaint_t blkcnt, const void *buffer)
 457 {
 458         blkcache_invalidate(block_dev->if_type, block_dev->devnum);
 459         return block_dev->block_write(block_dev, start, blkcnt, buffer);
 460 }
 461
 462 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
 463                                lbaint_t blkcnt)
 464 {
 465         blkcache_invalidate(block_dev->if_type, block_dev->devnum);
 466         return block_dev->block_erase(block_dev, start, blkcnt);
 467 }
 468
 469 /**
 470  * struct blk_driver - Driver for block interface types
 471  *
 472  * This provides access to the block devices for each interface type. One
 473  * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
 474  * type that is to be supported.
 475  *
 476  * @if_typename:        Interface type name
 477  * @if_type:            Interface type
 478  * @max_devs:           Maximum number of devices supported
 479  * @desc:               Pointer to list of devices for this interface type,
 480  *                      or NULL to use @get_dev() instead
 481  */
 482 struct blk_driver {
 483         const char *if_typename;
 484         enum if_type if_type;
 485         int max_devs;
 486         struct blk_desc *desc;
 487         /**
 488          * get_dev() - get a pointer to a block device given its number
 489          *
 490          * Each interface allocates its own devices and typically
 491          * struct blk_desc is contained with the interface's data structure.
 492          * There is no global numbering for block devices. This method allows
 493          * the device for an interface type to be obtained when @desc is NULL.
 494          *
 495          * @devnum:     Device number (0 for first device on that interface,
 496          *              1 for second, etc.
 497          * @descp:      Returns pointer to the block device on success
 498          * @return 0 if OK, -ve on error
 499          */
 500         int (*get_dev)(int devnum, struct blk_desc **descp);
 501
 502         /**
 503          * select_hwpart() - Select a hardware partition
 504          *
 505          * Some devices (e.g. MMC) can support partitioning at the hardware
 506          * level. This is quite separate from the normal idea of
 507          * software-based partitions. MMC hardware partitions must be
 508          * explicitly selected. Once selected only the region of the device
 509          * covered by that partition is accessible.
 510          *
 511          * The MMC standard provides for two boot partitions (numbered 1 and 2),
 512          * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
 513          * Partition 0 is the main user-data partition.
 514          *
 515          * @desc:       Block device descriptor
 516          * @hwpart:     Hardware partition number to select. 0 means the main
 517          *              user-data partition, 1 is the first partition, 2 is
 518          *              the second, etc.
 519          * @return 0 if OK, other value for an error
 520          */
 521         int (*select_hwpart)(struct blk_desc *desc, int hwpart);
 522 };
 523
 524 /*
 525  * Declare a new U-Boot legacy block driver. New drivers should use driver
 526  * model (UCLASS_BLK).
 527  */
 528 #define U_BOOT_LEGACY_BLK(__name)                                       \
 529         ll_entry_declare(struct blk_driver, __name, blk_driver)
 530
 531 struct blk_driver *blk_driver_lookup_type(int if_type);
 532
 533 #endif /* !CONFIG_BLK */
 534
 535 /**
 536  * blk_get_devnum_by_typename() - Get a block device by type and number
 537  *
 538  * This looks through the available block devices of the given type, returning
 539  * the one with the given @devnum.
 540  *
 541  * @if_type:    Block device type
 542  * @devnum:     Device number
 543  * @return point to block device descriptor, or NULL if not found
 544  */
 545 struct blk_desc *blk_get_devnum_by_type(enum if_type if_type, int devnum);
 546
 547 /**
 548  * blk_get_devnum_by_type() - Get a block device by type name, and number
 549  *
 550  * This looks up the block device type based on @if_typename, then calls
 551  * blk_get_devnum_by_type().
 552  *
 553  * @if_typename:        Block device type name
 554  * @devnum:             Device number
 555  * @return point to block device descriptor, or NULL if not found
 556  */
 557 struct blk_desc *blk_get_devnum_by_typename(const char *if_typename,
 558                                             int devnum);
 559
 560 /**
 561  * blk_dselect_hwpart() - select a hardware partition
 562  *
 563  * This selects a hardware partition (such as is supported by MMC). The block
 564  * device size may change as this effectively points the block device to a
 565  * partition at the hardware level. See the select_hwpart() method above.
 566  *
 567  * @desc:       Block device descriptor for the device to select
 568  * @hwpart:     Partition number to select
 569  * @return 0 if OK, -ve on error
 570  */
 571 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
 572
 573 /**
 574  * blk_list_part() - list the partitions for block devices of a given type
 575  *
 576  * This looks up the partition type for each block device of type @if_type,
 577  * then displays a list of partitions.
 578  *
 579  * @if_type:    Block device type
 580  * @return 0 if OK, -ENODEV if there is none of that type
 581  */
 582 int blk_list_part(enum if_type if_type);
 583
 584 /**
 585  * blk_list_devices() - list the block devices of a given type
 586  *
 587  * This lists each block device of the type @if_type, showing the capacity
 588  * as well as type-specific information.
 589  *
 590  * @if_type:    Block device type
 591  */
 592 void blk_list_devices(enum if_type if_type);
 593
 594 /**
 595  * blk_show_device() - show information about a given block device
 596  *
 597  * This shows the block device capacity as well as type-specific information.
 598  *
 599  * @if_type:    Block device type
 600  * @devnum:     Device number
 601  * @return 0 if OK, -ENODEV for invalid device number
 602  */
 603 int blk_show_device(enum if_type if_type, int devnum);
 604
 605 /**
 606  * blk_print_device_num() - show information about a given block device
 607  *
 608  * This is similar to blk_show_device() but returns an error if the block
 609  * device type is unknown.
 610  *
 611  * @if_type:    Block device type
 612  * @devnum:     Device number
 613  * @return 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
 614  * device is not connected
 615  */
 616 int blk_print_device_num(enum if_type if_type, int devnum);
 617
 618 /**
 619  * blk_print_part_devnum() - print the partition information for a device
 620  *
 621  * @if_type:    Block device type
 622  * @devnum:     Device number
 623  * @return 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
 624  * the interface type is not supported, other -ve on other error
 625  */
 626 int blk_print_part_devnum(enum if_type if_type, int devnum);
 627
 628 /**
 629  * blk_read_devnum() - read blocks from a device
 630  *
 631  * @if_type:    Block device type
 632  * @devnum:     Device number
 633  * @blkcnt:     Number of blocks to read
 634  * @buffer:     Address to write data to
 635  * @return number of blocks read, or -ve error number on error
 636  */
 637 ulong blk_read_devnum(enum if_type if_type, int devnum, lbaint_t start,
 638                       lbaint_t blkcnt, void *buffer);
 639
 640 /**
 641  * blk_write_devnum() - write blocks to a device
 642  *
 643  * @if_type:    Block device type
 644  * @devnum:     Device number
 645  * @blkcnt:     Number of blocks to write
 646  * @buffer:     Address to read data from
 647  * @return number of blocks written, or -ve error number on error
 648  */
 649 ulong blk_write_devnum(enum if_type if_type, int devnum, lbaint_t start,
 650                        lbaint_t blkcnt, const void *buffer);
 651
 652 /**
 653  * blk_select_hwpart_devnum() - select a hardware partition
 654  *
 655  * This is similar to blk_dselect_hwpart() but it looks up the interface and
 656  * device number.
 657  *
 658  * @if_type:    Block device type
 659  * @devnum:     Device number
 660  * @hwpart:     Partition number to select
 661  * @return 0 if OK, -ve on error
 662  */
 663 int blk_select_hwpart_devnum(enum if_type if_type, int devnum, int hwpart);
 664
 665 /**
 666  * blk_get_if_type_name() - Get the name of an interface type
 667  *
 668  * @if_type: Interface type to check
 669  * @return name of interface, or NULL if none
 670  */
 671 const char *blk_get_if_type_name(enum if_type if_type);
 672
 673 /**
 674  * blk_common_cmd() - handle common commands with block devices
 675  *
 676  * @args: Number of arguments to the command (argv[0] is the command itself)
 677  * @argv: Command arguments
 678  * @if_type: Interface type
 679  * @cur_devnump: Current device number for this interface type
 680  * @return 0 if OK, CMD_RET_ERROR on error
 681  */
 682 int blk_common_cmd(int argc, char *const argv[], enum if_type if_type,
 683                    int *cur_devnump);
 684
 685 #endif