xref: /openbmc/u-boot/drivers/mtd/ubi/ubi.h (revision 7ca6f363)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2006, 2007
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  *
7  * Author: Artem Bityutskiy (Битюцкий Артём)
8  */
9 
10 #ifndef __UBI_UBI_H__
11 #define __UBI_UBI_H__
12 
13 #ifdef UBI_LINUX
14 #include <linux/init.h>
15 #include <linux/types.h>
16 #include <linux/list.h>
17 #include <linux/rbtree.h>
18 #include <linux/sched.h>
19 #include <linux/wait.h>
20 #include <linux/mutex.h>
21 #include <linux/rwsem.h>
22 #include <linux/spinlock.h>
23 #include <linux/fs.h>
24 #include <linux/cdev.h>
25 #include <linux/device.h>
26 #include <linux/string.h>
27 #include <linux/vmalloc.h>
28 #include <linux/mtd/mtd.h>
29 #include <linux/mtd/ubi.h>
30 #endif
31 
32 #include <linux/types.h>
33 #include <linux/list.h>
34 #include <linux/rbtree.h>
35 #include <linux/string.h>
36 #include <linux/mtd/mtd.h>
37 #include <linux/mtd/ubi.h>
38 
39 #include "ubi-media.h"
40 #include "scan.h"
41 #include "debug.h"
42 
43 /* Maximum number of supported UBI devices */
44 #define UBI_MAX_DEVICES 32
45 
46 /* UBI name used for character devices, sysfs, etc */
47 #define UBI_NAME_STR "ubi"
48 
49 /* Normal UBI messages */
50 #ifdef CONFIG_UBI_SILENCE_MSG
51 #define ubi_msg(fmt, ...)
52 #else
53 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
54 #endif
55 /* UBI warning messages */
56 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
57 				  __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
60 				 __func__, ##__VA_ARGS__)
61 
62 /* Lowest number PEBs reserved for bad PEB handling */
63 #define MIN_RESEVED_PEBS 2
64 
65 /* Background thread name pattern */
66 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
67 
68 /* This marker in the EBA table means that the LEB is um-mapped */
69 #define UBI_LEB_UNMAPPED -1
70 
71 /*
72  * In case of errors, UBI tries to repeat the operation several times before
73  * returning error. The below constant defines how many times UBI re-tries.
74  */
75 #define UBI_IO_RETRIES 3
76 
77 /*
78  * Error codes returned by the I/O unit.
79  *
80  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
81  * 0xFF bytes
82  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
83  * valid erase counter header, and the rest are %0xFF bytes
84  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
85  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
86  * CRC)
87  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
88  */
89 enum {
90 	UBI_IO_PEB_EMPTY = 1,
91 	UBI_IO_PEB_FREE,
92 	UBI_IO_BAD_EC_HDR,
93 	UBI_IO_BAD_VID_HDR,
94 	UBI_IO_BITFLIPS
95 };
96 
97 /**
98  * struct ubi_wl_entry - wear-leveling entry.
99  * @rb: link in the corresponding RB-tree
100  * @ec: erase counter
101  * @pnum: physical eraseblock number
102  *
103  * This data structure is used in the WL unit. Each physical eraseblock has a
104  * corresponding &struct wl_entry object which may be kept in different
105  * RB-trees. See WL unit for details.
106  */
107 struct ubi_wl_entry {
108 	struct rb_node rb;
109 	int ec;
110 	int pnum;
111 };
112 
113 /**
114  * struct ubi_ltree_entry - an entry in the lock tree.
115  * @rb: links RB-tree nodes
116  * @vol_id: volume ID of the locked logical eraseblock
117  * @lnum: locked logical eraseblock number
118  * @users: how many tasks are using this logical eraseblock or wait for it
119  * @mutex: read/write mutex to implement read/write access serialization to
120  *         the (@vol_id, @lnum) logical eraseblock
121  *
122  * This data structure is used in the EBA unit to implement per-LEB locking.
123  * When a logical eraseblock is being locked - corresponding
124  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
125  * See EBA unit for details.
126  */
127 struct ubi_ltree_entry {
128 	struct rb_node rb;
129 	int vol_id;
130 	int lnum;
131 	int users;
132 	struct rw_semaphore mutex;
133 };
134 
135 struct ubi_volume_desc;
136 
137 /**
138  * struct ubi_volume - UBI volume description data structure.
139  * @dev: device object to make use of the the Linux device model
140  * @cdev: character device object to create character device
141  * @ubi: reference to the UBI device description object
142  * @vol_id: volume ID
143  * @ref_count: volume reference count
144  * @readers: number of users holding this volume in read-only mode
145  * @writers: number of users holding this volume in read-write mode
146  * @exclusive: whether somebody holds this volume in exclusive mode
147  *
148  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
149  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
150  * @usable_leb_size: logical eraseblock size without padding
151  * @used_ebs: how many logical eraseblocks in this volume contain data
152  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
153  * @used_bytes: how many bytes of data this volume contains
154  * @alignment: volume alignment
155  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
156  *            satisfy the requested alignment
157  * @name_len: volume name length
158  * @name: volume name
159  *
160  * @upd_ebs: how many eraseblocks are expected to be updated
161  * @ch_lnum: LEB number which is being changing by the atomic LEB change
162  *           operation
163  * @ch_dtype: data persistency type which is being changing by the atomic LEB
164  *            change operation
165  * @upd_bytes: how many bytes are expected to be received for volume update or
166  *             atomic LEB change
167  * @upd_received: how many bytes were already received for volume update or
168  *                atomic LEB change
169  * @upd_buf: update buffer which is used to collect update data or data for
170  *           atomic LEB change
171  *
172  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
173  * @checked: %1 if this static volume was checked
174  * @corrupted: %1 if the volume is corrupted (static volumes only)
175  * @upd_marker: %1 if the update marker is set for this volume
176  * @updating: %1 if the volume is being updated
177  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
178  *
179  * @gluebi_desc: gluebi UBI volume descriptor
180  * @gluebi_refcount: reference count of the gluebi MTD device
181  * @gluebi_mtd: MTD device description object of the gluebi MTD device
182  *
183  * The @corrupted field indicates that the volume's contents is corrupted.
184  * Since UBI protects only static volumes, this field is not relevant to
185  * dynamic volumes - it is user's responsibility to assure their data
186  * integrity.
187  *
188  * The @upd_marker flag indicates that this volume is either being updated at
189  * the moment or is damaged because of an unclean reboot.
190  */
191 struct ubi_volume {
192 	struct device dev;
193 	struct cdev cdev;
194 	struct ubi_device *ubi;
195 	int vol_id;
196 	int ref_count;
197 	int readers;
198 	int writers;
199 	int exclusive;
200 
201 	int reserved_pebs;
202 	int vol_type;
203 	int usable_leb_size;
204 	int used_ebs;
205 	int last_eb_bytes;
206 	long long used_bytes;
207 	int alignment;
208 	int data_pad;
209 	int name_len;
210 	char name[UBI_VOL_NAME_MAX+1];
211 
212 	int upd_ebs;
213 	int ch_lnum;
214 	int ch_dtype;
215 	long long upd_bytes;
216 	long long upd_received;
217 	void *upd_buf;
218 
219 	int *eba_tbl;
220 	unsigned int checked:1;
221 	unsigned int corrupted:1;
222 	unsigned int upd_marker:1;
223 	unsigned int updating:1;
224 	unsigned int changing_leb:1;
225 
226 #ifdef CONFIG_MTD_UBI_GLUEBI
227 	/*
228 	 * Gluebi-related stuff may be compiled out.
229 	 * TODO: this should not be built into UBI but should be a separate
230 	 * ubimtd driver which works on top of UBI and emulates MTD devices.
231 	 */
232 	struct ubi_volume_desc *gluebi_desc;
233 	int gluebi_refcount;
234 	struct mtd_info gluebi_mtd;
235 #endif
236 };
237 
238 /**
239  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
240  * opened.
241  * @vol: reference to the corresponding volume description object
242  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
243  */
244 struct ubi_volume_desc {
245 	struct ubi_volume *vol;
246 	int mode;
247 };
248 
249 struct ubi_wl_entry;
250 
251 /**
252  * struct ubi_device - UBI device description structure
253  * @dev: UBI device object to use the the Linux device model
254  * @cdev: character device object to create character device
255  * @ubi_num: UBI device number
256  * @ubi_name: UBI device name
257  * @vol_count: number of volumes in this UBI device
258  * @volumes: volumes of this UBI device
259  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
260  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
261  *                @vol->readers, @vol->writers, @vol->exclusive,
262  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
263  * @ref_count: count of references on the UBI device
264  *
265  * @rsvd_pebs: count of reserved physical eraseblocks
266  * @avail_pebs: count of available physical eraseblocks
267  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
268  *                 handling
269  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
270  *
271  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
272  *                     of UBI ititializetion
273  * @vtbl_slots: how many slots are available in the volume table
274  * @vtbl_size: size of the volume table in bytes
275  * @vtbl: in-RAM volume table copy
276  * @volumes_mutex: protects on-flash volume table and serializes volume
277  *                 changes, like creation, deletion, update, resize
278  *
279  * @max_ec: current highest erase counter value
280  * @mean_ec: current mean erase counter value
281  *
282  * @global_sqnum: global sequence number
283  * @ltree_lock: protects the lock tree and @global_sqnum
284  * @ltree: the lock tree
285  * @alc_mutex: serializes "atomic LEB change" operations
286  *
287  * @used: RB-tree of used physical eraseblocks
288  * @free: RB-tree of free physical eraseblocks
289  * @scrub: RB-tree of physical eraseblocks which need scrubbing
290  * @prot: protection trees
291  * @prot.pnum: protection tree indexed by physical eraseblock numbers
292  * @prot.aec: protection tree indexed by absolute erase counter value
293  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
294  *           @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
295  *           fields
296  * @move_mutex: serializes eraseblock moves
297  * @wl_scheduled: non-zero if the wear-leveling was scheduled
298  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
299  *             physical eraseblock
300  * @abs_ec: absolute erase counter
301  * @move_from: physical eraseblock from where the data is being moved
302  * @move_to: physical eraseblock where the data is being moved to
303  * @move_to_put: if the "to" PEB was put
304  * @works: list of pending works
305  * @works_count: count of pending works
306  * @bgt_thread: background thread description object
307  * @thread_enabled: if the background thread is enabled
308  * @bgt_name: background thread name
309  *
310  * @flash_size: underlying MTD device size (in bytes)
311  * @peb_count: count of physical eraseblocks on the MTD device
312  * @peb_size: physical eraseblock size
313  * @bad_peb_count: count of bad physical eraseblocks
314  * @good_peb_count: count of good physical eraseblocks
315  * @min_io_size: minimal input/output unit size of the underlying MTD device
316  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
317  * @ro_mode: if the UBI device is in read-only mode
318  * @leb_size: logical eraseblock size
319  * @leb_start: starting offset of logical eraseblocks within physical
320  * eraseblocks
321  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
322  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
323  * @vid_hdr_offset: starting offset of the volume identifier header (might be
324  * unaligned)
325  * @vid_hdr_aloffset: starting offset of the VID header aligned to
326  * @hdrs_min_io_size
327  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
328  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
329  *               not
330  * @mtd: MTD device descriptor
331  *
332  * @peb_buf1: a buffer of PEB size used for different purposes
333  * @peb_buf2: another buffer of PEB size used for different purposes
334  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
335  * @dbg_peb_buf: buffer of PEB size used for debugging
336  * @dbg_buf_mutex: proptects @dbg_peb_buf
337  */
338 struct ubi_device {
339 	struct cdev cdev;
340 	struct device dev;
341 	int ubi_num;
342 	char ubi_name[sizeof(UBI_NAME_STR)+5];
343 	int vol_count;
344 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
345 	spinlock_t volumes_lock;
346 	int ref_count;
347 
348 	int rsvd_pebs;
349 	int avail_pebs;
350 	int beb_rsvd_pebs;
351 	int beb_rsvd_level;
352 
353 	int autoresize_vol_id;
354 	int vtbl_slots;
355 	int vtbl_size;
356 	struct ubi_vtbl_record *vtbl;
357 	struct mutex volumes_mutex;
358 
359 	int max_ec;
360 	/* TODO: mean_ec is not updated run-time, fix */
361 	int mean_ec;
362 
363 	/* EBA unit's stuff */
364 	unsigned long long global_sqnum;
365 	spinlock_t ltree_lock;
366 	struct rb_root ltree;
367 	struct mutex alc_mutex;
368 
369 	/* Wear-leveling unit's stuff */
370 	struct rb_root used;
371 	struct rb_root free;
372 	struct rb_root scrub;
373 	struct {
374 		struct rb_root pnum;
375 		struct rb_root aec;
376 	} prot;
377 	spinlock_t wl_lock;
378 	struct mutex move_mutex;
379 	struct rw_semaphore work_sem;
380 	int wl_scheduled;
381 	struct ubi_wl_entry **lookuptbl;
382 	unsigned long long abs_ec;
383 	struct ubi_wl_entry *move_from;
384 	struct ubi_wl_entry *move_to;
385 	int move_to_put;
386 	struct list_head works;
387 	int works_count;
388 	struct task_struct *bgt_thread;
389 	int thread_enabled;
390 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
391 
392 	/* I/O unit's stuff */
393 	long long flash_size;
394 	int peb_count;
395 	int peb_size;
396 	int bad_peb_count;
397 	int good_peb_count;
398 	int min_io_size;
399 	int hdrs_min_io_size;
400 	int ro_mode;
401 	int leb_size;
402 	int leb_start;
403 	int ec_hdr_alsize;
404 	int vid_hdr_alsize;
405 	int vid_hdr_offset;
406 	int vid_hdr_aloffset;
407 	int vid_hdr_shift;
408 	int bad_allowed;
409 	struct mtd_info *mtd;
410 
411 	void *peb_buf1;
412 	void *peb_buf2;
413 	struct mutex buf_mutex;
414 	struct mutex ckvol_mutex;
415 #ifdef CONFIG_MTD_UBI_DEBUG
416 	void *dbg_peb_buf;
417 	struct mutex dbg_buf_mutex;
418 #endif
419 };
420 
421 extern struct kmem_cache *ubi_wl_entry_slab;
422 extern struct file_operations ubi_ctrl_cdev_operations;
423 extern struct file_operations ubi_cdev_operations;
424 extern struct file_operations ubi_vol_cdev_operations;
425 extern struct class *ubi_class;
426 extern struct mutex ubi_devices_mutex;
427 
428 /* vtbl.c */
429 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
430 			   struct ubi_vtbl_record *vtbl_rec);
431 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
432 
433 /* vmt.c */
434 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
435 int ubi_remove_volume(struct ubi_volume_desc *desc);
436 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
437 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
438 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
439 
440 /* upd.c */
441 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
442 		     long long bytes);
443 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
444 			 const void __user *buf, int count);
445 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
446 			 const struct ubi_leb_change_req *req);
447 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
448 			     const void __user *buf, int count);
449 
450 /* misc.c */
451 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
452 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
453 void ubi_calculate_reserved(struct ubi_device *ubi);
454 
455 /* gluebi.c */
456 #ifdef CONFIG_MTD_UBI_GLUEBI
457 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
458 int ubi_destroy_gluebi(struct ubi_volume *vol);
459 void ubi_gluebi_updated(struct ubi_volume *vol);
460 #else
461 #define ubi_create_gluebi(ubi, vol) 0
462 
463 static inline int ubi_destroy_gluebi(struct ubi_volume *vol)
464 {
465 	return 0;
466 }
467 
468 #define ubi_gluebi_updated(vol)
469 #endif
470 
471 /* eba.c */
472 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
473 		      int lnum);
474 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
475 		     void *buf, int offset, int len, int check);
476 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
477 		      const void *buf, int offset, int len, int dtype);
478 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
479 			 int lnum, const void *buf, int len, int dtype,
480 			 int used_ebs);
481 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
482 			      int lnum, const void *buf, int len, int dtype);
483 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
484 		     struct ubi_vid_hdr *vid_hdr);
485 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
486 void ubi_eba_close(const struct ubi_device *ubi);
487 
488 /* wl.c */
489 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
490 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
491 int ubi_wl_flush(struct ubi_device *ubi);
492 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
493 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
494 void ubi_wl_close(struct ubi_device *ubi);
495 int ubi_thread(void *u);
496 
497 /* io.c */
498 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
499 		int len);
500 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
501 		 int len);
502 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
503 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
504 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
505 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
506 		       struct ubi_ec_hdr *ec_hdr, int verbose);
507 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
508 			struct ubi_ec_hdr *ec_hdr);
509 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
510 			struct ubi_vid_hdr *vid_hdr, int verbose);
511 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
512 			 struct ubi_vid_hdr *vid_hdr);
513 
514 /* build.c */
515 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
516 int ubi_detach_mtd_dev(int ubi_num, int anyway);
517 struct ubi_device *ubi_get_device(int ubi_num);
518 void ubi_put_device(struct ubi_device *ubi);
519 struct ubi_device *ubi_get_by_major(int major);
520 int ubi_major2num(int major);
521 
522 /*
523  * ubi_rb_for_each_entry - walk an RB-tree.
524  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
525  * @pos: a pointer to RB-tree entry type to use as a loop counter
526  * @root: RB-tree's root
527  * @member: the name of the 'struct rb_node' within the RB-tree entry
528  */
529 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
530 	for (rb = rb_first(root),                                            \
531 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
532 	     rb;                                                             \
533 	     rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
534 
535 /**
536  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
537  * @ubi: UBI device description object
538  * @gfp_flags: GFP flags to allocate with
539  *
540  * This function returns a pointer to the newly allocated and zero-filled
541  * volume identifier header object in case of success and %NULL in case of
542  * failure.
543  */
544 static inline struct ubi_vid_hdr *
545 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
546 {
547 	void *vid_hdr;
548 
549 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
550 	if (!vid_hdr)
551 		return NULL;
552 
553 	/*
554 	 * VID headers may be stored at un-aligned flash offsets, so we shift
555 	 * the pointer.
556 	 */
557 	return vid_hdr + ubi->vid_hdr_shift;
558 }
559 
560 /**
561  * ubi_free_vid_hdr - free a volume identifier header object.
562  * @ubi: UBI device description object
563  * @vid_hdr: the object to free
564  */
565 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
566 				    struct ubi_vid_hdr *vid_hdr)
567 {
568 	void *p = vid_hdr;
569 
570 	if (!p)
571 		return;
572 
573 	kfree(p - ubi->vid_hdr_shift);
574 }
575 
576 /*
577  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
578  * the beginning of the logical eraseblock, not to the beginning of the
579  * physical eraseblock.
580  */
581 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
582 				   int pnum, int offset, int len)
583 {
584 	ubi_assert(offset >= 0);
585 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
586 }
587 
588 /*
589  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
590  * the beginning of the logical eraseblock, not to the beginning of the
591  * physical eraseblock.
592  */
593 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
594 				    int pnum, int offset, int len)
595 {
596 	ubi_assert(offset >= 0);
597 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
598 }
599 
600 /**
601  * ubi_ro_mode - switch to read-only mode.
602  * @ubi: UBI device description object
603  */
604 static inline void ubi_ro_mode(struct ubi_device *ubi)
605 {
606 	if (!ubi->ro_mode) {
607 		ubi->ro_mode = 1;
608 		ubi_warn("switch to read-only mode");
609 	}
610 }
611 
612 /**
613  * vol_id2idx - get table index by volume ID.
614  * @ubi: UBI device description object
615  * @vol_id: volume ID
616  */
617 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
618 {
619 	if (vol_id >= UBI_INTERNAL_VOL_START)
620 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
621 	else
622 		return vol_id;
623 }
624 
625 /**
626  * idx2vol_id - get volume ID by table index.
627  * @ubi: UBI device description object
628  * @idx: table index
629  */
630 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
631 {
632 	if (idx >= ubi->vtbl_slots)
633 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
634 	else
635 		return idx;
636 }
637 
638 #endif /* !__UBI_UBI_H__ */
639