xref: /openbmc/u-boot/include/blk.h (revision 1d6edcbf)
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  * blkcache_read() - attempt to read a set of blocks from cache
118  *
119  * @param iftype - IF_TYPE_x for type of device
120  * @param dev - device index of particular type
121  * @param start - starting block number
122  * @param blkcnt - number of blocks to read
123  * @param blksz - size in bytes of each block
124  * @param buf - buffer to contain cached data
125  *
126  * @return - '1' if block returned from cache, '0' otherwise.
127  */
128 int blkcache_read(int iftype, int dev,
129 		  lbaint_t start, lbaint_t blkcnt,
130 		  unsigned long blksz, void *buffer);
131 
132 /**
133  * blkcache_fill() - make data read from a block device available
134  * to the block cache
135  *
136  * @param iftype - IF_TYPE_x for type of device
137  * @param dev - device index of particular type
138  * @param start - starting block number
139  * @param blkcnt - number of blocks available
140  * @param blksz - size in bytes of each block
141  * @param buf - buffer containing data to cache
142  *
143  */
144 void blkcache_fill(int iftype, int dev,
145 		   lbaint_t start, lbaint_t blkcnt,
146 		   unsigned long blksz, void const *buffer);
147 
148 /**
149  * blkcache_invalidate() - discard the cache for a set of blocks
150  * because of a write or device (re)initialization.
151  *
152  * @param iftype - IF_TYPE_x for type of device
153  * @param dev - device index of particular type
154  */
155 void blkcache_invalidate(int iftype, int dev);
156 
157 /**
158  * blkcache_configure() - configure block cache
159  *
160  * @param blocks - maximum blocks per entry
161  * @param entries - maximum entries in cache
162  */
163 void blkcache_configure(unsigned blocks, unsigned entries);
164 
165 /*
166  * statistics of the block cache
167  */
168 struct block_cache_stats {
169 	unsigned hits;
170 	unsigned misses;
171 	unsigned entries; /* current entry count */
172 	unsigned max_blocks_per_entry;
173 	unsigned max_entries;
174 };
175 
176 /**
177  * get_blkcache_stats() - return statistics and reset
178  *
179  * @param stats - statistics are copied here
180  */
181 void blkcache_stats(struct block_cache_stats *stats);
182 
183 #else
184 
blkcache_read(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void * buffer)185 static inline int blkcache_read(int iftype, int dev,
186 				lbaint_t start, lbaint_t blkcnt,
187 				unsigned long blksz, void *buffer)
188 {
189 	return 0;
190 }
191 
blkcache_fill(int iftype,int dev,lbaint_t start,lbaint_t blkcnt,unsigned long blksz,void const * buffer)192 static inline void blkcache_fill(int iftype, int dev,
193 				 lbaint_t start, lbaint_t blkcnt,
194 				 unsigned long blksz, void const *buffer) {}
195 
blkcache_invalidate(int iftype,int dev)196 static inline void blkcache_invalidate(int iftype, int dev) {}
197 
198 #endif
199 
200 #if CONFIG_IS_ENABLED(BLK)
201 struct udevice;
202 
203 /* Operations on block devices */
204 struct blk_ops {
205 	/**
206 	 * read() - read from a block device
207 	 *
208 	 * @dev:	Device to read from
209 	 * @start:	Start block number to read (0=first)
210 	 * @blkcnt:	Number of blocks to read
211 	 * @buffer:	Destination buffer for data read
212 	 * @return number of blocks read, or -ve error number (see the
213 	 * IS_ERR_VALUE() macro
214 	 */
215 	unsigned long (*read)(struct udevice *dev, lbaint_t start,
216 			      lbaint_t blkcnt, void *buffer);
217 
218 	/**
219 	 * write() - write to a block device
220 	 *
221 	 * @dev:	Device to write to
222 	 * @start:	Start block number to write (0=first)
223 	 * @blkcnt:	Number of blocks to write
224 	 * @buffer:	Source buffer for data to write
225 	 * @return number of blocks written, or -ve error number (see the
226 	 * IS_ERR_VALUE() macro
227 	 */
228 	unsigned long (*write)(struct udevice *dev, lbaint_t start,
229 			       lbaint_t blkcnt, const void *buffer);
230 
231 	/**
232 	 * erase() - erase a section of a block device
233 	 *
234 	 * @dev:	Device to (partially) erase
235 	 * @start:	Start block number to erase (0=first)
236 	 * @blkcnt:	Number of blocks to erase
237 	 * @return number of blocks erased, or -ve error number (see the
238 	 * IS_ERR_VALUE() macro
239 	 */
240 	unsigned long (*erase)(struct udevice *dev, lbaint_t start,
241 			       lbaint_t blkcnt);
242 
243 	/**
244 	 * select_hwpart() - select a particular hardware partition
245 	 *
246 	 * Some devices (e.g. MMC) can support partitioning at the hardware
247 	 * level. This is quite separate from the normal idea of
248 	 * software-based partitions. MMC hardware partitions must be
249 	 * explicitly selected. Once selected only the region of the device
250 	 * covered by that partition is accessible.
251 	 *
252 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
253 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
254 	 *
255 	 * @desc:	Block device to update
256 	 * @hwpart:	Hardware partition number to select. 0 means the raw
257 	 *		device, 1 is the first partition, 2 is the second, etc.
258 	 * @return 0 if OK, -ve on error
259 	 */
260 	int (*select_hwpart)(struct udevice *dev, int hwpart);
261 };
262 
263 #define blk_get_ops(dev)	((struct blk_ops *)(dev)->driver->ops)
264 
265 /*
266  * These functions should take struct udevice instead of struct blk_desc,
267  * but this is convenient for migration to driver model. Add a 'd' prefix
268  * to the function operations, so that blk_read(), etc. can be reserved for
269  * functions with the correct arguments.
270  */
271 unsigned long blk_dread(struct blk_desc *block_dev, lbaint_t start,
272 			lbaint_t blkcnt, void *buffer);
273 unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
274 			 lbaint_t blkcnt, const void *buffer);
275 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
276 			 lbaint_t blkcnt);
277 
278 /**
279  * blk_find_device() - Find a block device
280  *
281  * This function does not activate the device. The device will be returned
282  * whether or not it is activated.
283  *
284  * @if_type:	Interface type (enum if_type_t)
285  * @devnum:	Device number (specific to each interface type)
286  * @devp:	the device, if found
287  * @return 0 if found, -ENODEV if no device found, or other -ve error value
288  */
289 int blk_find_device(int if_type, int devnum, struct udevice **devp);
290 
291 /**
292  * blk_get_device() - Find and probe a block device ready for use
293  *
294  * @if_type:	Interface type (enum if_type_t)
295  * @devnum:	Device number (specific to each interface type)
296  * @devp:	the device, if found
297  * @return 0 if found, -ENODEV if no device found, or other -ve error value
298  */
299 int blk_get_device(int if_type, int devnum, struct udevice **devp);
300 
301 /**
302  * blk_first_device() - Find the first device for a given interface
303  *
304  * The device is probed ready for use
305  *
306  * @devnum:	Device number (specific to each interface type)
307  * @devp:	the device, if found
308  * @return 0 if found, -ENODEV if no device, or other -ve error value
309  */
310 int blk_first_device(int if_type, struct udevice **devp);
311 
312 /**
313  * blk_next_device() - Find the next device for a given interface
314  *
315  * This can be called repeatedly after blk_first_device() to iterate through
316  * all devices of the given interface type.
317  *
318  * The device is probed ready for use
319  *
320  * @devp:	On entry, the previous device returned. On exit, the next
321  *		device, if found
322  * @return 0 if found, -ENODEV if no device, or other -ve error value
323  */
324 int blk_next_device(struct udevice **devp);
325 
326 /**
327  * blk_create_device() - Create a new block device
328  *
329  * @parent:	Parent of the new device
330  * @drv_name:	Driver name to use for the block device
331  * @name:	Name for the device
332  * @if_type:	Interface type (enum if_type_t)
333  * @devnum:	Device number, specific to the interface type, or -1 to
334  *		allocate the next available number
335  * @blksz:	Block size of the device in bytes (typically 512)
336  * @lba:	Total number of blocks of the device
337  * @devp:	the new device (which has not been probed)
338  */
339 int blk_create_device(struct udevice *parent, const char *drv_name,
340 		      const char *name, int if_type, int devnum, int blksz,
341 		      lbaint_t lba, struct udevice **devp);
342 
343 /**
344  * blk_create_devicef() - Create a new named block device
345  *
346  * @parent:	Parent of the new device
347  * @drv_name:	Driver name to use for the block device
348  * @name:	Name for the device (parent name is prepended)
349  * @if_type:	Interface type (enum if_type_t)
350  * @devnum:	Device number, specific to the interface type, or -1 to
351  *		allocate the next available number
352  * @blksz:	Block size of the device in bytes (typically 512)
353  * @lba:	Total number of blocks of the device
354  * @devp:	the new device (which has not been probed)
355  */
356 int blk_create_devicef(struct udevice *parent, const char *drv_name,
357 		       const char *name, int if_type, int devnum, int blksz,
358 		       lbaint_t lba, struct udevice **devp);
359 
360 /**
361  * blk_unbind_all() - Unbind all device of the given interface type
362  *
363  * The devices are removed and then unbound.
364  *
365  * @if_type:	Interface type to unbind
366  * @return 0 if OK, -ve on error
367  */
368 int blk_unbind_all(int if_type);
369 
370 /**
371  * blk_find_max_devnum() - find the maximum device number for an interface type
372  *
373  * Finds the last allocated device number for an interface type @if_type. The
374  * next number is safe to use for a newly allocated device.
375  *
376  * @if_type:	Interface type to scan
377  * @return maximum device number found, or -ENODEV if none, or other -ve on
378  * error
379  */
380 int blk_find_max_devnum(enum if_type if_type);
381 
382 /**
383  * blk_next_free_devnum() - get the next device number for an interface type
384  *
385  * Finds the next number that is safe to use for a newly allocated device for
386  * an interface type @if_type.
387  *
388  * @if_type:	Interface type to scan
389  * @return next device number safe to use, or -ve on error
390  */
391 int blk_next_free_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 /**
412  * blk_get_by_device() - Get the block device descriptor for the given device
413  * @dev:	Instance of a storage device
414  *
415  * Return: With block device descriptor on success , NULL if there is no such
416  *	   block device.
417  */
418 struct blk_desc *blk_get_by_device(struct udevice *dev);
419 
420 #else
421 #include <errno.h>
422 /*
423  * These functions should take struct udevice instead of struct blk_desc,
424  * but this is convenient for migration to driver model. Add a 'd' prefix
425  * to the function operations, so that blk_read(), etc. can be reserved for
426  * functions with the correct arguments.
427  */
blk_dread(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,void * buffer)428 static inline ulong blk_dread(struct blk_desc *block_dev, lbaint_t start,
429 			      lbaint_t blkcnt, void *buffer)
430 {
431 	ulong blks_read;
432 	if (blkcache_read(block_dev->if_type, block_dev->devnum,
433 			  start, blkcnt, block_dev->blksz, buffer))
434 		return blkcnt;
435 
436 	/*
437 	 * We could check if block_read is NULL and return -ENOSYS. But this
438 	 * bloats the code slightly (cause some board to fail to build), and
439 	 * it would be an error to try an operation that does not exist.
440 	 */
441 	blks_read = block_dev->block_read(block_dev, start, blkcnt, buffer);
442 	if (blks_read == blkcnt)
443 		blkcache_fill(block_dev->if_type, block_dev->devnum,
444 			      start, blkcnt, block_dev->blksz, buffer);
445 
446 	return blks_read;
447 }
448 
blk_dwrite(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt,const void * buffer)449 static inline ulong blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
450 			       lbaint_t blkcnt, const void *buffer)
451 {
452 	blkcache_invalidate(block_dev->if_type, block_dev->devnum);
453 	return block_dev->block_write(block_dev, start, blkcnt, buffer);
454 }
455 
blk_derase(struct blk_desc * block_dev,lbaint_t start,lbaint_t blkcnt)456 static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
457 			       lbaint_t blkcnt)
458 {
459 	blkcache_invalidate(block_dev->if_type, block_dev->devnum);
460 	return block_dev->block_erase(block_dev, start, blkcnt);
461 }
462 
463 /**
464  * struct blk_driver - Driver for block interface types
465  *
466  * This provides access to the block devices for each interface type. One
467  * driver should be provided using U_BOOT_LEGACY_BLK() for each interface
468  * type that is to be supported.
469  *
470  * @if_typename:	Interface type name
471  * @if_type:		Interface type
472  * @max_devs:		Maximum number of devices supported
473  * @desc:		Pointer to list of devices for this interface type,
474  *			or NULL to use @get_dev() instead
475  */
476 struct blk_driver {
477 	const char *if_typename;
478 	enum if_type if_type;
479 	int max_devs;
480 	struct blk_desc *desc;
481 	/**
482 	 * get_dev() - get a pointer to a block device given its number
483 	 *
484 	 * Each interface allocates its own devices and typically
485 	 * struct blk_desc is contained with the interface's data structure.
486 	 * There is no global numbering for block devices. This method allows
487 	 * the device for an interface type to be obtained when @desc is NULL.
488 	 *
489 	 * @devnum:	Device number (0 for first device on that interface,
490 	 *		1 for second, etc.
491 	 * @descp:	Returns pointer to the block device on success
492 	 * @return 0 if OK, -ve on error
493 	 */
494 	int (*get_dev)(int devnum, struct blk_desc **descp);
495 
496 	/**
497 	 * select_hwpart() - Select a hardware partition
498 	 *
499 	 * Some devices (e.g. MMC) can support partitioning at the hardware
500 	 * level. This is quite separate from the normal idea of
501 	 * software-based partitions. MMC hardware partitions must be
502 	 * explicitly selected. Once selected only the region of the device
503 	 * covered by that partition is accessible.
504 	 *
505 	 * The MMC standard provides for two boot partitions (numbered 1 and 2),
506 	 * rpmb (3), and up to 4 addition general-purpose partitions (4-7).
507 	 * Partition 0 is the main user-data partition.
508 	 *
509 	 * @desc:	Block device descriptor
510 	 * @hwpart:	Hardware partition number to select. 0 means the main
511 	 *		user-data partition, 1 is the first partition, 2 is
512 	 *		the second, etc.
513 	 * @return 0 if OK, other value for an error
514 	 */
515 	int (*select_hwpart)(struct blk_desc *desc, int hwpart);
516 };
517 
518 /*
519  * Declare a new U-Boot legacy block driver. New drivers should use driver
520  * model (UCLASS_BLK).
521  */
522 #define U_BOOT_LEGACY_BLK(__name)					\
523 	ll_entry_declare(struct blk_driver, __name, blk_driver)
524 
525 struct blk_driver *blk_driver_lookup_type(int if_type);
526 
527 #endif /* !CONFIG_BLK */
528 
529 /**
530  * blk_get_devnum_by_typename() - Get a block device by type and number
531  *
532  * This looks through the available block devices of the given type, returning
533  * the one with the given @devnum.
534  *
535  * @if_type:	Block device type
536  * @devnum:	Device number
537  * @return point to block device descriptor, or NULL if not found
538  */
539 struct blk_desc *blk_get_devnum_by_type(enum if_type if_type, int devnum);
540 
541 /**
542  * blk_get_devnum_by_type() - Get a block device by type name, and number
543  *
544  * This looks up the block device type based on @if_typename, then calls
545  * blk_get_devnum_by_type().
546  *
547  * @if_typename:	Block device type name
548  * @devnum:		Device number
549  * @return point to block device descriptor, or NULL if not found
550  */
551 struct blk_desc *blk_get_devnum_by_typename(const char *if_typename,
552 					    int devnum);
553 
554 /**
555  * blk_dselect_hwpart() - select a hardware partition
556  *
557  * This selects a hardware partition (such as is supported by MMC). The block
558  * device size may change as this effectively points the block device to a
559  * partition at the hardware level. See the select_hwpart() method above.
560  *
561  * @desc:	Block device descriptor for the device to select
562  * @hwpart:	Partition number to select
563  * @return 0 if OK, -ve on error
564  */
565 int blk_dselect_hwpart(struct blk_desc *desc, int hwpart);
566 
567 /**
568  * blk_list_part() - list the partitions for block devices of a given type
569  *
570  * This looks up the partition type for each block device of type @if_type,
571  * then displays a list of partitions.
572  *
573  * @if_type:	Block device type
574  * @return 0 if OK, -ENODEV if there is none of that type
575  */
576 int blk_list_part(enum if_type if_type);
577 
578 /**
579  * blk_list_devices() - list the block devices of a given type
580  *
581  * This lists each block device of the type @if_type, showing the capacity
582  * as well as type-specific information.
583  *
584  * @if_type:	Block device type
585  */
586 void blk_list_devices(enum if_type if_type);
587 
588 /**
589  * blk_show_device() - show information about a given block device
590  *
591  * This shows the block device capacity as well as type-specific information.
592  *
593  * @if_type:	Block device type
594  * @devnum:	Device number
595  * @return 0 if OK, -ENODEV for invalid device number
596  */
597 int blk_show_device(enum if_type if_type, int devnum);
598 
599 /**
600  * blk_print_device_num() - show information about a given block device
601  *
602  * This is similar to blk_show_device() but returns an error if the block
603  * device type is unknown.
604  *
605  * @if_type:	Block device type
606  * @devnum:	Device number
607  * @return 0 if OK, -ENODEV for invalid device number, -ENOENT if the block
608  * device is not connected
609  */
610 int blk_print_device_num(enum if_type if_type, int devnum);
611 
612 /**
613  * blk_print_part_devnum() - print the partition information for a device
614  *
615  * @if_type:	Block device type
616  * @devnum:	Device number
617  * @return 0 if OK, -ENOENT if the block device is not connected, -ENOSYS if
618  * the interface type is not supported, other -ve on other error
619  */
620 int blk_print_part_devnum(enum if_type if_type, int devnum);
621 
622 /**
623  * blk_read_devnum() - read blocks from a device
624  *
625  * @if_type:	Block device type
626  * @devnum:	Device number
627  * @blkcnt:	Number of blocks to read
628  * @buffer:	Address to write data to
629  * @return number of blocks read, or -ve error number on error
630  */
631 ulong blk_read_devnum(enum if_type if_type, int devnum, lbaint_t start,
632 		      lbaint_t blkcnt, void *buffer);
633 
634 /**
635  * blk_write_devnum() - write blocks to a device
636  *
637  * @if_type:	Block device type
638  * @devnum:	Device number
639  * @blkcnt:	Number of blocks to write
640  * @buffer:	Address to read data from
641  * @return number of blocks written, or -ve error number on error
642  */
643 ulong blk_write_devnum(enum if_type if_type, int devnum, lbaint_t start,
644 		       lbaint_t blkcnt, const void *buffer);
645 
646 /**
647  * blk_select_hwpart_devnum() - select a hardware partition
648  *
649  * This is similar to blk_dselect_hwpart() but it looks up the interface and
650  * device number.
651  *
652  * @if_type:	Block device type
653  * @devnum:	Device number
654  * @hwpart:	Partition number to select
655  * @return 0 if OK, -ve on error
656  */
657 int blk_select_hwpart_devnum(enum if_type if_type, int devnum, int hwpart);
658 
659 /**
660  * blk_get_if_type_name() - Get the name of an interface type
661  *
662  * @if_type: Interface type to check
663  * @return name of interface, or NULL if none
664  */
665 const char *blk_get_if_type_name(enum if_type if_type);
666 
667 /**
668  * blk_common_cmd() - handle common commands with block devices
669  *
670  * @args: Number of arguments to the command (argv[0] is the command itself)
671  * @argv: Command arguments
672  * @if_type: Interface type
673  * @cur_devnump: Current device number for this interface type
674  * @return 0 if OK, CMD_RET_ERROR on error
675  */
676 int blk_common_cmd(int argc, char * const argv[], enum if_type if_type,
677 		   int *cur_devnump);
678 
679 #endif
680