xref: /linux/drivers/mtd/ubi/ubi.h (revision 5027ec19f1049a07df5b0a37b1f462514cf2724b)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright (c) International Business Machines Corp., 2006
4  * Copyright (c) Nokia Corporation, 2006, 2007
5  *
6  * Author: Artem Bityutskiy (Битюцкий Артём)
7  */
8 
9 #ifndef __UBI_UBI_H__
10 #define __UBI_UBI_H__
11 
12 #include <linux/types.h>
13 #include <linux/list.h>
14 #include <linux/rbtree.h>
15 #include <linux/sched.h>
16 #include <linux/wait.h>
17 #include <linux/mutex.h>
18 #include <linux/rwsem.h>
19 #include <linux/spinlock.h>
20 #include <linux/fs.h>
21 #include <linux/cdev.h>
22 #include <linux/device.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/vmalloc.h>
26 #include <linux/notifier.h>
27 #include <linux/mtd/mtd.h>
28 #include <linux/mtd/ubi.h>
29 #include <linux/pgtable.h>
30 
31 #include "ubi-media.h"
32 
33 /* Maximum number of supported UBI devices */
34 #define UBI_MAX_DEVICES 32
35 
36 /* UBI name used for character devices, sysfs, etc */
37 #define UBI_NAME_STR "ubi"
38 
39 struct ubi_device;
40 
41 /* Normal UBI messages */
42 __printf(2, 3)
43 void ubi_msg(const struct ubi_device *ubi, const char *fmt, ...);
44 
45 /* UBI warning messages */
46 __printf(2, 3)
47 void ubi_warn(const struct ubi_device *ubi, const char *fmt, ...);
48 
49 /* UBI error messages */
50 __printf(2, 3)
51 void ubi_err(const struct ubi_device *ubi, const char *fmt, ...);
52 
53 /* Background thread name pattern */
54 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
55 
56 /*
57  * This marker in the EBA table means that the LEB is um-mapped.
58  * NOTE! It has to have the same value as %UBI_ALL.
59  */
60 #define UBI_LEB_UNMAPPED -1
61 
62 /*
63  * In case of errors, UBI tries to repeat the operation several times before
64  * returning error. The below constant defines how many times UBI re-tries.
65  */
66 #define UBI_IO_RETRIES 3
67 
68 /*
69  * Length of the protection queue. The length is effectively equivalent to the
70  * number of (global) erase cycles PEBs are protected from the wear-leveling
71  * worker.
72  */
73 #define UBI_PROT_QUEUE_LEN 10
74 
75 /* The volume ID/LEB number/erase counter is unknown */
76 #define UBI_UNKNOWN -1
77 
78 /*
79  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
80  * + 2 for the number plus 1 for the trailing zero byte.
81  */
82 #define UBI_DFS_DIR_NAME "ubi%d"
83 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
84 
85 /* Number of physical eraseblocks reserved for atomic LEB change operation */
86 #define EBA_RESERVED_PEBS 1
87 
88 /*
89  * Error codes returned by the I/O sub-system.
90  *
91  * UBI_IO_FF: the read region of flash contains only 0xFFs
92  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also there was a data
93  *                     integrity error reported by the MTD driver
94  *                     (uncorrectable ECC error in case of NAND)
95  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
96  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
97  *                         data integrity error reported by the MTD driver
98  *                         (uncorrectable ECC error in case of NAND)
99  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
100  *
101  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
102  * be or'ed with other error code. But this is a big change because there are
103  * may callers, so it does not worth the risk of introducing a bug
104  */
105 enum {
106 	UBI_IO_FF = 1,
107 	UBI_IO_FF_BITFLIPS,
108 	UBI_IO_BAD_HDR,
109 	UBI_IO_BAD_HDR_EBADMSG,
110 	UBI_IO_BITFLIPS,
111 };
112 
113 /*
114  * Return codes of the 'ubi_eba_copy_leb()' function.
115  *
116  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
117  *                   PEB was put meanwhile, or there is I/O on the source PEB
118  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
119  *                     PEB
120  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
121  *                     PEB
122  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
123  *                     PEB
124  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
125  *                       target PEB
126  * MOVE_RETRY: retry scrubbing the PEB
127  */
128 enum {
129 	MOVE_CANCEL_RACE = 1,
130 	MOVE_SOURCE_RD_ERR,
131 	MOVE_TARGET_RD_ERR,
132 	MOVE_TARGET_WR_ERR,
133 	MOVE_TARGET_BITFLIPS,
134 	MOVE_RETRY,
135 };
136 
137 /*
138  * Return codes of the fastmap sub-system
139  *
140  * UBI_NO_FASTMAP: No fastmap super block was found
141  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
142  */
143 enum {
144 	UBI_NO_FASTMAP = 1,
145 	UBI_BAD_FASTMAP,
146 };
147 
148 /*
149  * Flags for emulate_power_cut in ubi_debug_info
150  *
151  * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
152  * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
153  */
154 enum {
155 	POWER_CUT_EC_WRITE = 0x01,
156 	POWER_CUT_VID_WRITE = 0x02,
157 };
158 
159 /**
160  * struct ubi_vid_io_buf - VID buffer used to read/write VID info to/from the
161  *			   flash.
162  * @hdr: a pointer to the VID header stored in buffer
163  * @buffer: underlying buffer
164  */
165 struct ubi_vid_io_buf {
166 	struct ubi_vid_hdr *hdr;
167 	void *buffer;
168 };
169 
170 /**
171  * struct ubi_wl_entry - wear-leveling entry.
172  * @u.rb: link in the corresponding (free/used) RB-tree
173  * @u.list: link in the protection queue
174  * @ec: erase counter
175  * @pnum: physical eraseblock number
176  *
177  * This data structure is used in the WL sub-system. Each physical eraseblock
178  * has a corresponding &struct wl_entry object which may be kept in different
179  * RB-trees. See WL sub-system for details.
180  */
181 struct ubi_wl_entry {
182 	union {
183 		struct rb_node rb;
184 		struct list_head list;
185 	} u;
186 	int ec;
187 	int pnum;
188 };
189 
190 /**
191  * struct ubi_ltree_entry - an entry in the lock tree.
192  * @rb: links RB-tree nodes
193  * @vol_id: volume ID of the locked logical eraseblock
194  * @lnum: locked logical eraseblock number
195  * @users: how many tasks are using this logical eraseblock or wait for it
196  * @mutex: read/write mutex to implement read/write access serialization to
197  *         the (@vol_id, @lnum) logical eraseblock
198  *
199  * This data structure is used in the EBA sub-system to implement per-LEB
200  * locking. When a logical eraseblock is being locked - corresponding
201  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
202  * See EBA sub-system for details.
203  */
204 struct ubi_ltree_entry {
205 	struct rb_node rb;
206 	int vol_id;
207 	int lnum;
208 	int users;
209 	struct rw_semaphore mutex;
210 };
211 
212 /**
213  * struct ubi_rename_entry - volume re-name description data structure.
214  * @new_name_len: new volume name length
215  * @new_name: new volume name
216  * @remove: if not zero, this volume should be removed, not re-named
217  * @desc: descriptor of the volume
218  * @list: links re-name entries into a list
219  *
220  * This data structure is utilized in the multiple volume re-name code. Namely,
221  * UBI first creates a list of &struct ubi_rename_entry objects from the
222  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
223  * the job.
224  */
225 struct ubi_rename_entry {
226 	int new_name_len;
227 	char new_name[UBI_VOL_NAME_MAX + 1];
228 	int remove;
229 	struct ubi_volume_desc *desc;
230 	struct list_head list;
231 };
232 
233 struct ubi_volume_desc;
234 
235 /**
236  * struct ubi_fastmap_layout - in-memory fastmap data structure.
237  * @e: PEBs used by the current fastmap
238  * @to_be_tortured: if non-zero tortured this PEB
239  * @used_blocks: number of used PEBs
240  * @max_pool_size: maximal size of the user pool
241  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
242  */
243 struct ubi_fastmap_layout {
244 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
245 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
246 	int used_blocks;
247 	int max_pool_size;
248 	int max_wl_pool_size;
249 };
250 
251 /**
252  * struct ubi_fm_pool - in-memory fastmap pool
253  * @pebs: PEBs in this pool
254  * @used: number of used PEBs
255  * @size: total number of PEBs in this pool
256  * @max_size: maximal size of the pool
257  *
258  * A pool gets filled with up to max_size.
259  * If all PEBs within the pool are used a new fastmap will be written
260  * to the flash and the pool gets refilled with empty PEBs.
261  *
262  */
263 struct ubi_fm_pool {
264 	int pebs[UBI_FM_MAX_POOL_SIZE];
265 	int used;
266 	int size;
267 	int max_size;
268 };
269 
270 /**
271  * struct ubi_eba_leb_desc - EBA logical eraseblock descriptor
272  * @lnum: the logical eraseblock number
273  * @pnum: the physical eraseblock where the LEB can be found
274  *
275  * This structure is here to hide EBA's internal from other part of the
276  * UBI implementation.
277  *
278  * One can query the position of a LEB by calling ubi_eba_get_ldesc().
279  */
280 struct ubi_eba_leb_desc {
281 	int lnum;
282 	int pnum;
283 };
284 
285 /**
286  * struct ubi_volume - UBI volume description data structure.
287  * @dev: device object to make use of the Linux device model
288  * @cdev: character device object to create character device
289  * @ubi: reference to the UBI device description object
290  * @vol_id: volume ID
291  * @ref_count: volume reference count
292  * @readers: number of users holding this volume in read-only mode
293  * @writers: number of users holding this volume in read-write mode
294  * @exclusive: whether somebody holds this volume in exclusive mode
295  * @metaonly: whether somebody is altering only meta data of this volume
296  *
297  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
298  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
299  * @usable_leb_size: logical eraseblock size without padding
300  * @used_ebs: how many logical eraseblocks in this volume contain data
301  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
302  * @used_bytes: how many bytes of data this volume contains
303  * @alignment: volume alignment
304  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
305  *            satisfy the requested alignment
306  * @name_len: volume name length
307  * @name: volume name
308  *
309  * @upd_ebs: how many eraseblocks are expected to be updated
310  * @ch_lnum: LEB number which is being changing by the atomic LEB change
311  *           operation
312  * @upd_bytes: how many bytes are expected to be received for volume update or
313  *             atomic LEB change
314  * @upd_received: how many bytes were already received for volume update or
315  *                atomic LEB change
316  * @upd_buf: update buffer which is used to collect update data or data for
317  *           atomic LEB change
318  *
319  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
320  * @skip_check: %1 if CRC check of this static volume should be skipped.
321  *		Directly reflects the presence of the
322  *		%UBI_VTBL_SKIP_CRC_CHECK_FLG flag in the vtbl entry
323  * @checked: %1 if this static volume was checked
324  * @corrupted: %1 if the volume is corrupted (static volumes only)
325  * @upd_marker: %1 if the update marker is set for this volume
326  * @updating: %1 if the volume is being updated
327  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
328  * @direct_writes: %1 if direct writes are enabled for this volume
329  *
330  * @checkmap: bitmap to remember which PEB->LEB mappings got checked,
331  *            protected by UBI LEB lock tree.
332  *
333  * The @corrupted field indicates that the volume's contents is corrupted.
334  * Since UBI protects only static volumes, this field is not relevant to
335  * dynamic volumes - it is user's responsibility to assure their data
336  * integrity.
337  *
338  * The @upd_marker flag indicates that this volume is either being updated at
339  * the moment or is damaged because of an unclean reboot.
340  */
341 struct ubi_volume {
342 	struct device dev;
343 	struct cdev cdev;
344 	struct ubi_device *ubi;
345 	int vol_id;
346 	int ref_count;
347 	int readers;
348 	int writers;
349 	int exclusive;
350 	int metaonly;
351 
352 	int reserved_pebs;
353 	int vol_type;
354 	int usable_leb_size;
355 	int used_ebs;
356 	int last_eb_bytes;
357 	long long used_bytes;
358 	int alignment;
359 	int data_pad;
360 	int name_len;
361 	char name[UBI_VOL_NAME_MAX + 1];
362 
363 	int upd_ebs;
364 	int ch_lnum;
365 	long long upd_bytes;
366 	long long upd_received;
367 	void *upd_buf;
368 
369 	struct ubi_eba_table *eba_tbl;
370 	unsigned int skip_check:1;
371 	unsigned int checked:1;
372 	unsigned int corrupted:1;
373 	unsigned int upd_marker:1;
374 	unsigned int updating:1;
375 	unsigned int changing_leb:1;
376 	unsigned int direct_writes:1;
377 
378 #ifdef CONFIG_MTD_UBI_FASTMAP
379 	unsigned long *checkmap;
380 #endif
381 };
382 
383 /**
384  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
385  * @vol: reference to the corresponding volume description object
386  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
387  * or %UBI_METAONLY)
388  */
389 struct ubi_volume_desc {
390 	struct ubi_volume *vol;
391 	int mode;
392 };
393 
394 /**
395  * struct ubi_debug_info - debugging information for an UBI device.
396  *
397  * @chk_gen: if UBI general extra checks are enabled
398  * @chk_io: if UBI I/O extra checks are enabled
399  * @chk_fastmap: if UBI fastmap extra checks are enabled
400  * @disable_bgt: disable the background task for testing purposes
401  * @emulate_bitflips: emulate bit-flips for testing purposes
402  * @emulate_io_failures: emulate write/erase failures for testing purposes
403  * @emulate_power_cut: emulate power cut for testing purposes
404  * @power_cut_counter: count down for writes left until emulated power cut
405  * @power_cut_min: minimum number of writes before emulating a power cut
406  * @power_cut_max: maximum number of writes until emulating a power cut
407  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
408  * @dfs_dir: direntry object of the UBI device debugfs directory
409  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
410  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
411  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
412  * @dfs_disable_bgt: debugfs knob to disable the background task
413  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
414  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
415  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
416  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
417  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
418  */
419 struct ubi_debug_info {
420 	unsigned int chk_gen:1;
421 	unsigned int chk_io:1;
422 	unsigned int chk_fastmap:1;
423 	unsigned int disable_bgt:1;
424 	unsigned int emulate_bitflips:1;
425 	unsigned int emulate_io_failures:1;
426 	unsigned int emulate_power_cut:2;
427 	unsigned int power_cut_counter;
428 	unsigned int power_cut_min;
429 	unsigned int power_cut_max;
430 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
431 	struct dentry *dfs_dir;
432 	struct dentry *dfs_chk_gen;
433 	struct dentry *dfs_chk_io;
434 	struct dentry *dfs_chk_fastmap;
435 	struct dentry *dfs_disable_bgt;
436 	struct dentry *dfs_emulate_bitflips;
437 	struct dentry *dfs_emulate_io_failures;
438 	struct dentry *dfs_emulate_power_cut;
439 	struct dentry *dfs_power_cut_min;
440 	struct dentry *dfs_power_cut_max;
441 };
442 
443 /**
444  * struct ubi_device - UBI device description structure
445  * @dev: UBI device object to use the Linux device model
446  * @cdev: character device object to create character device
447  * @ubi_num: UBI device number
448  * @ubi_name: UBI device name
449  * @vol_count: number of volumes in this UBI device
450  * @volumes: volumes of this UBI device
451  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
452  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
453  *                @vol->readers, @vol->writers, @vol->exclusive,
454  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
455  *                @vol->eba_tbl.
456  * @ref_count: count of references on the UBI device
457  * @image_seq: image sequence number recorded on EC headers
458  *
459  * @rsvd_pebs: count of reserved physical eraseblocks
460  * @avail_pebs: count of available physical eraseblocks
461  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
462  *                 handling
463  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
464  *
465  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
466  *                     of UBI initialization
467  * @vtbl_slots: how many slots are available in the volume table
468  * @vtbl_size: size of the volume table in bytes
469  * @vtbl: in-RAM volume table copy
470  * @device_mutex: protects on-flash volume table and serializes volume
471  *                creation, deletion, update, re-size, re-name and set
472  *                property
473  *
474  * @max_ec: current highest erase counter value
475  * @mean_ec: current mean erase counter value
476  *
477  * @global_sqnum: global sequence number
478  * @ltree_lock: protects the lock tree and @global_sqnum
479  * @ltree: the lock tree
480  * @alc_mutex: serializes "atomic LEB change" operations
481  *
482  * @fm_disabled: non-zero if fastmap is disabled (default)
483  * @fm: in-memory data structure of the currently used fastmap
484  * @fm_pool: in-memory data structure of the fastmap pool
485  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
486  *		sub-system
487  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
488  * that critical sections cannot be interrupted by ubi_update_fastmap()
489  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
490  * @fm_size: fastmap size in bytes
491  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
492  * @fm_work: fastmap work queue
493  * @fm_work_scheduled: non-zero if fastmap work was scheduled
494  * @fast_attach: non-zero if UBI was attached by fastmap
495  * @fm_anchor: The next anchor PEB to use for fastmap
496  * @fm_do_produce_anchor: If true produce an anchor PEB in wl
497  * @fm_pool_rsv_cnt: Number of reserved PEBs for filling pool/wl_pool
498  *
499  * @used: RB-tree of used physical eraseblocks
500  * @erroneous: RB-tree of erroneous used physical eraseblocks
501  * @free: RB-tree of free physical eraseblocks
502  * @free_count: Contains the number of elements in @free
503  * @scrub: RB-tree of physical eraseblocks which need scrubbing
504  * @pq: protection queue (contain physical eraseblocks which are temporarily
505  *      protected from the wear-leveling worker)
506  * @pq_head: protection queue head
507  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
508  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
509  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
510  *	     and @fm_wl_pool fields
511  * @move_mutex: serializes eraseblock moves
512  * @work_sem: used to wait for all the scheduled works to finish and prevent
513  * new works from being submitted
514  * @wl_scheduled: non-zero if the wear-leveling was scheduled
515  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
516  *             physical eraseblock
517  * @move_from: physical eraseblock from where the data is being moved
518  * @move_to: physical eraseblock where the data is being moved to
519  * @move_to_put: if the "to" PEB was put
520  * @works: list of pending works
521  * @works_count: count of pending works
522  * @bgt_thread: background thread description object
523  * @thread_enabled: if the background thread is enabled
524  * @bgt_name: background thread name
525  *
526  * @flash_size: underlying MTD device size (in bytes)
527  * @peb_count: count of physical eraseblocks on the MTD device
528  * @peb_size: physical eraseblock size
529  * @bad_peb_limit: top limit of expected bad physical eraseblocks
530  * @bad_peb_count: count of bad physical eraseblocks
531  * @good_peb_count: count of good physical eraseblocks
532  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
533  *                  used by UBI)
534  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
535  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
536  * @min_io_size: minimal input/output unit size of the underlying MTD device
537  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
538  * @ro_mode: if the UBI device is in read-only mode
539  * @leb_size: logical eraseblock size
540  * @leb_start: starting offset of logical eraseblocks within physical
541  *             eraseblocks
542  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
543  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
544  * @vid_hdr_offset: starting offset of the volume identifier header (might be
545  *                  unaligned)
546  * @vid_hdr_aloffset: starting offset of the VID header aligned to
547  *                    @hdrs_min_io_size
548  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
549  * @bad_allowed: whether the MTD device admits bad physical eraseblocks or not
550  * @nor_flash: non-zero if working on top of NOR flash
551  * @max_write_size: maximum amount of bytes the underlying flash can write at a
552  *                  time (MTD write buffer size)
553  * @mtd: MTD device descriptor
554  *
555  * @peb_buf: a buffer of PEB size used for different purposes
556  * @buf_mutex: protects @peb_buf
557  * @ckvol_mutex: serializes static volume checking when opening
558  *
559  * @dbg: debugging information for this UBI device
560  */
561 struct ubi_device {
562 	struct cdev cdev;
563 	struct device dev;
564 	int ubi_num;
565 	char ubi_name[sizeof(UBI_NAME_STR)+5];
566 	int vol_count;
567 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
568 	spinlock_t volumes_lock;
569 	int ref_count;
570 	int image_seq;
571 
572 	int rsvd_pebs;
573 	int avail_pebs;
574 	int beb_rsvd_pebs;
575 	int beb_rsvd_level;
576 	int bad_peb_limit;
577 
578 	int autoresize_vol_id;
579 	int vtbl_slots;
580 	int vtbl_size;
581 	struct ubi_vtbl_record *vtbl;
582 	struct mutex device_mutex;
583 
584 	int max_ec;
585 	/* Note, mean_ec is not updated run-time - should be fixed */
586 	int mean_ec;
587 
588 	/* EBA sub-system's stuff */
589 	unsigned long long global_sqnum;
590 	spinlock_t ltree_lock;
591 	struct rb_root ltree;
592 	struct mutex alc_mutex;
593 
594 	/* Fastmap stuff */
595 	int fm_disabled;
596 	struct ubi_fastmap_layout *fm;
597 	struct ubi_fm_pool fm_pool;
598 	struct ubi_fm_pool fm_wl_pool;
599 	struct rw_semaphore fm_eba_sem;
600 	struct rw_semaphore fm_protect;
601 	void *fm_buf;
602 	size_t fm_size;
603 	struct work_struct fm_work;
604 	int fm_work_scheduled;
605 	int fast_attach;
606 	struct ubi_wl_entry *fm_anchor;
607 	int fm_do_produce_anchor;
608 	int fm_pool_rsv_cnt;
609 
610 	/* Wear-leveling sub-system's stuff */
611 	struct rb_root used;
612 	struct rb_root erroneous;
613 	struct rb_root free;
614 	int free_count;
615 	struct rb_root scrub;
616 	struct list_head pq[UBI_PROT_QUEUE_LEN];
617 	int pq_head;
618 	spinlock_t wl_lock;
619 	struct mutex move_mutex;
620 	struct rw_semaphore work_sem;
621 	int wl_scheduled;
622 	struct ubi_wl_entry **lookuptbl;
623 	struct ubi_wl_entry *move_from;
624 	struct ubi_wl_entry *move_to;
625 	int move_to_put;
626 	struct list_head works;
627 	int works_count;
628 	struct task_struct *bgt_thread;
629 	int thread_enabled;
630 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
631 
632 	/* I/O sub-system's stuff */
633 	long long flash_size;
634 	int peb_count;
635 	int peb_size;
636 	int bad_peb_count;
637 	int good_peb_count;
638 	int corr_peb_count;
639 	int erroneous_peb_count;
640 	int max_erroneous;
641 	int min_io_size;
642 	int hdrs_min_io_size;
643 	int ro_mode;
644 	int leb_size;
645 	int leb_start;
646 	int ec_hdr_alsize;
647 	int vid_hdr_alsize;
648 	int vid_hdr_offset;
649 	int vid_hdr_aloffset;
650 	int vid_hdr_shift;
651 	unsigned int bad_allowed:1;
652 	unsigned int nor_flash:1;
653 	int max_write_size;
654 	struct mtd_info *mtd;
655 
656 	void *peb_buf;
657 	struct mutex buf_mutex;
658 	struct mutex ckvol_mutex;
659 
660 	struct ubi_debug_info dbg;
661 };
662 
663 /**
664  * struct ubi_ainf_peb - attach information about a physical eraseblock.
665  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
666  * @pnum: physical eraseblock number
667  * @vol_id: ID of the volume this LEB belongs to
668  * @lnum: logical eraseblock number
669  * @scrub: if this physical eraseblock needs scrubbing
670  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
671  * @sqnum: sequence number
672  * @u: unions RB-tree or @list links
673  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
674  * @u.list: link in one of the eraseblock lists
675  *
676  * One object of this type is allocated for each physical eraseblock when
677  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
678  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
679  */
680 struct ubi_ainf_peb {
681 	int ec;
682 	int pnum;
683 	int vol_id;
684 	int lnum;
685 	unsigned int scrub:1;
686 	unsigned int copy_flag:1;
687 	unsigned long long sqnum;
688 	union {
689 		struct rb_node rb;
690 		struct list_head list;
691 	} u;
692 };
693 
694 /**
695  * struct ubi_ainf_volume - attaching information about a volume.
696  * @vol_id: volume ID
697  * @highest_lnum: highest logical eraseblock number in this volume
698  * @leb_count: number of logical eraseblocks in this volume
699  * @vol_type: volume type
700  * @used_ebs: number of used logical eraseblocks in this volume (only for
701  *            static volumes)
702  * @last_data_size: amount of data in the last logical eraseblock of this
703  *                  volume (always equivalent to the usable logical eraseblock
704  *                  size in case of dynamic volumes)
705  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
706  *            are not used (due to volume alignment)
707  * @compat: compatibility flags of this volume
708  * @rb: link in the volume RB-tree
709  * @root: root of the RB-tree containing all the eraseblock belonging to this
710  *        volume (&struct ubi_ainf_peb objects)
711  *
712  * One object of this type is allocated for each volume when attaching an MTD
713  * device.
714  */
715 struct ubi_ainf_volume {
716 	int vol_id;
717 	int highest_lnum;
718 	int leb_count;
719 	int vol_type;
720 	int used_ebs;
721 	int last_data_size;
722 	int data_pad;
723 	int compat;
724 	struct rb_node rb;
725 	struct rb_root root;
726 };
727 
728 /**
729  * struct ubi_attach_info - MTD device attaching information.
730  * @volumes: root of the volume RB-tree
731  * @corr: list of corrupted physical eraseblocks
732  * @free: list of free physical eraseblocks
733  * @erase: list of physical eraseblocks which have to be erased
734  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
735  *         those belonging to "preserve"-compatible internal volumes)
736  * @fastmap: list of physical eraseblocks which relate to fastmap (e.g.,
737  *           eraseblocks of the current and not yet erased old fastmap blocks)
738  * @corr_peb_count: count of PEBs in the @corr list
739  * @empty_peb_count: count of PEBs which are presumably empty (contain only
740  *                   0xFF bytes)
741  * @alien_peb_count: count of PEBs in the @alien list
742  * @bad_peb_count: count of bad physical eraseblocks
743  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
744  *                       as bad yet, but which look like bad
745  * @vols_found: number of volumes found
746  * @highest_vol_id: highest volume ID
747  * @is_empty: flag indicating whether the MTD device is empty or not
748  * @force_full_scan: flag indicating whether we need to do a full scan and drop
749 		     all existing Fastmap data structures
750  * @min_ec: lowest erase counter value
751  * @max_ec: highest erase counter value
752  * @max_sqnum: highest sequence number value
753  * @mean_ec: mean erase counter value
754  * @ec_sum: a temporary variable used when calculating @mean_ec
755  * @ec_count: a temporary variable used when calculating @mean_ec
756  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
757  * @ech: temporary EC header. Only available during scan
758  * @vidh: temporary VID buffer. Only available during scan
759  *
760  * This data structure contains the result of attaching an MTD device and may
761  * be used by other UBI sub-systems to build final UBI data structures, further
762  * error-recovery and so on.
763  */
764 struct ubi_attach_info {
765 	struct rb_root volumes;
766 	struct list_head corr;
767 	struct list_head free;
768 	struct list_head erase;
769 	struct list_head alien;
770 	struct list_head fastmap;
771 	int corr_peb_count;
772 	int empty_peb_count;
773 	int alien_peb_count;
774 	int bad_peb_count;
775 	int maybe_bad_peb_count;
776 	int vols_found;
777 	int highest_vol_id;
778 	int is_empty;
779 	int force_full_scan;
780 	int min_ec;
781 	int max_ec;
782 	unsigned long long max_sqnum;
783 	int mean_ec;
784 	uint64_t ec_sum;
785 	int ec_count;
786 	struct kmem_cache *aeb_slab_cache;
787 	struct ubi_ec_hdr *ech;
788 	struct ubi_vid_io_buf *vidb;
789 };
790 
791 /**
792  * struct ubi_work - UBI work description data structure.
793  * @list: a link in the list of pending works
794  * @func: worker function
795  * @e: physical eraseblock to erase
796  * @vol_id: the volume ID on which this erasure is being performed
797  * @lnum: the logical eraseblock number
798  * @torture: if the physical eraseblock has to be tortured
799  *
800  * The @func pointer points to the worker function. If the @shutdown argument is
801  * not zero, the worker has to free the resources and exit immediately as the
802  * WL sub-system is shutting down.
803  * The worker has to return zero in case of success and a negative error code in
804  * case of failure.
805  */
806 struct ubi_work {
807 	struct list_head list;
808 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
809 	/* The below fields are only relevant to erasure works */
810 	struct ubi_wl_entry *e;
811 	int vol_id;
812 	int lnum;
813 	int torture;
814 };
815 
816 #include "debug.h"
817 
818 extern struct kmem_cache *ubi_wl_entry_slab;
819 extern const struct file_operations ubi_ctrl_cdev_operations;
820 extern const struct file_operations ubi_cdev_operations;
821 extern const struct file_operations ubi_vol_cdev_operations;
822 extern struct class ubi_class;
823 extern struct mutex ubi_devices_mutex;
824 extern struct blocking_notifier_head ubi_notifiers;
825 
826 /* attach.c */
827 struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
828 				   int ec);
829 void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb);
830 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
831 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
832 struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id);
833 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
834 				    int vol_id);
835 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
836 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
837 				       struct ubi_attach_info *ai);
838 int ubi_attach(struct ubi_device *ubi, int force_scan);
839 void ubi_destroy_ai(struct ubi_attach_info *ai);
840 
841 /* vtbl.c */
842 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
843 			   struct ubi_vtbl_record *vtbl_rec);
844 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
845 			    struct list_head *rename_list);
846 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
847 
848 /* vmt.c */
849 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
850 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
851 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
852 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
853 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
854 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
855 
856 /* upd.c */
857 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
858 		     long long bytes);
859 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
860 			 const void __user *buf, int count);
861 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
862 			 const struct ubi_leb_change_req *req);
863 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
864 			     const void __user *buf, int count);
865 
866 /* misc.c */
867 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
868 		      int length);
869 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
870 void ubi_update_reserved(struct ubi_device *ubi);
871 void ubi_calculate_reserved(struct ubi_device *ubi);
872 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
873 
874 static inline bool ubi_leb_valid(struct ubi_volume *vol, int lnum)
875 {
876 	return lnum >= 0 && lnum < vol->reserved_pebs;
877 }
878 
879 /* eba.c */
880 struct ubi_eba_table *ubi_eba_create_table(struct ubi_volume *vol,
881 					   int nentries);
882 void ubi_eba_destroy_table(struct ubi_eba_table *tbl);
883 void ubi_eba_copy_table(struct ubi_volume *vol, struct ubi_eba_table *dst,
884 			int nentries);
885 void ubi_eba_replace_table(struct ubi_volume *vol, struct ubi_eba_table *tbl);
886 void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
887 		       struct ubi_eba_leb_desc *ldesc);
888 bool ubi_eba_is_mapped(struct ubi_volume *vol, int lnum);
889 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
890 		      int lnum);
891 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
892 		     void *buf, int offset, int len, int check);
893 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
894 			struct ubi_sgl *sgl, int lnum, int offset, int len,
895 			int check);
896 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
897 		      const void *buf, int offset, int len);
898 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
899 			 int lnum, const void *buf, int len, int used_ebs);
900 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
901 			      int lnum, const void *buf, int len);
902 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
903 		     struct ubi_vid_io_buf *vidb);
904 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
905 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
906 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
907 		   struct ubi_attach_info *ai_scan);
908 
909 /* wl.c */
910 int ubi_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture);
911 int ubi_wl_get_peb(struct ubi_device *ubi);
912 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
913 		   int pnum, int torture);
914 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
915 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
916 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
917 void ubi_wl_close(struct ubi_device *ubi);
918 int ubi_thread(void *u);
919 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
920 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
921 		      int lnum, int torture);
922 int ubi_is_erase_work(struct ubi_work *wrk);
923 void ubi_refill_pools_and_lock(struct ubi_device *ubi);
924 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
925 int ubi_bitflip_check(struct ubi_device *ubi, int pnum, int force_scrub);
926 
927 /* io.c */
928 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
929 		int len);
930 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
931 		 int len);
932 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
933 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
934 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
935 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
936 		       struct ubi_ec_hdr *ec_hdr, int verbose);
937 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
938 			struct ubi_ec_hdr *ec_hdr);
939 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
940 			struct ubi_vid_io_buf *vidb, int verbose);
941 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
942 			 struct ubi_vid_io_buf *vidb);
943 
944 /* build.c */
945 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
946 		       int vid_hdr_offset, int max_beb_per1024,
947 		       bool disable_fm, bool need_resv_pool);
948 int ubi_detach_mtd_dev(int ubi_num, int anyway);
949 struct ubi_device *ubi_get_device(int ubi_num);
950 void ubi_put_device(struct ubi_device *ubi);
951 struct ubi_device *ubi_get_by_major(int major);
952 int ubi_major2num(int major);
953 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
954 		      int ntype);
955 int ubi_notify_all(struct ubi_device *ubi, int ntype,
956 		   struct notifier_block *nb);
957 int ubi_enumerate_volumes(struct notifier_block *nb);
958 void ubi_free_all_volumes(struct ubi_device *ubi);
959 void ubi_free_internal_volumes(struct ubi_device *ubi);
960 
961 /* kapi.c */
962 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
963 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
964 			    struct ubi_volume_info *vi);
965 /* scan.c */
966 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
967 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
968 
969 /* fastmap.c */
970 #ifdef CONFIG_MTD_UBI_FASTMAP
971 size_t ubi_calc_fm_size(struct ubi_device *ubi);
972 int ubi_update_fastmap(struct ubi_device *ubi);
973 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
974 		     struct ubi_attach_info *scan_ai);
975 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count);
976 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol);
977 #else
978 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
979 static inline int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count) { return 0; }
980 static inline void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol) {}
981 #endif
982 
983 /* block.c */
984 #ifdef CONFIG_MTD_UBI_BLOCK
985 int ubiblock_init(void);
986 void ubiblock_exit(void);
987 int ubiblock_create(struct ubi_volume_info *vi);
988 int ubiblock_remove(struct ubi_volume_info *vi);
989 #else
990 static inline int ubiblock_init(void) { return 0; }
991 static inline void ubiblock_exit(void) {}
992 static inline int ubiblock_create(struct ubi_volume_info *vi)
993 {
994 	return -ENOSYS;
995 }
996 static inline int ubiblock_remove(struct ubi_volume_info *vi)
997 {
998 	return -ENOSYS;
999 }
1000 #endif
1001 
1002 /*
1003  * ubi_for_each_free_peb - walk the UBI free RB tree.
1004  * @ubi: UBI device description object
1005  * @e: a pointer to a ubi_wl_entry to use as cursor
1006  * @pos: a pointer to RB-tree entry type to use as a loop counter
1007  */
1008 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
1009 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
1010 
1011 /*
1012  * ubi_for_each_used_peb - walk the UBI used RB tree.
1013  * @ubi: UBI device description object
1014  * @e: a pointer to a ubi_wl_entry to use as cursor
1015  * @pos: a pointer to RB-tree entry type to use as a loop counter
1016  */
1017 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
1018 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
1019 
1020 /*
1021  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
1022  * @ubi: UBI device description object
1023  * @e: a pointer to a ubi_wl_entry to use as cursor
1024  * @pos: a pointer to RB-tree entry type to use as a loop counter
1025  */
1026 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
1027 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
1028 
1029 /*
1030  * ubi_for_each_protected_peb - walk the UBI protection queue.
1031  * @ubi: UBI device description object
1032  * @i: a integer used as counter
1033  * @e: a pointer to a ubi_wl_entry to use as cursor
1034  */
1035 #define ubi_for_each_protected_peb(ubi, i, e)	\
1036 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
1037 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
1038 
1039 /*
1040  * ubi_rb_for_each_entry - walk an RB-tree.
1041  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
1042  * @pos: a pointer to RB-tree entry type to use as a loop counter
1043  * @root: RB-tree's root
1044  * @member: the name of the 'struct rb_node' within the RB-tree entry
1045  */
1046 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
1047 	for (rb = rb_first(root),                                            \
1048 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
1049 	     rb;                                                             \
1050 	     rb = rb_next(rb),                                               \
1051 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
1052 
1053 /*
1054  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
1055  *
1056  * @av: volume attaching information
1057  * @aeb: attaching eraseblock information
1058  * @list: the list to move to
1059  */
1060 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
1061 					 struct ubi_ainf_peb *aeb,
1062 					 struct list_head *list)
1063 {
1064 		rb_erase(&aeb->u.rb, &av->root);
1065 		list_add_tail(&aeb->u.list, list);
1066 }
1067 
1068 /**
1069  * ubi_init_vid_buf - Initialize a VID buffer
1070  * @ubi: the UBI device
1071  * @vidb: the VID buffer to initialize
1072  * @buf: the underlying buffer
1073  */
1074 static inline void ubi_init_vid_buf(const struct ubi_device *ubi,
1075 				    struct ubi_vid_io_buf *vidb,
1076 				    void *buf)
1077 {
1078 	if (buf)
1079 		memset(buf, 0, ubi->vid_hdr_alsize);
1080 
1081 	vidb->buffer = buf;
1082 	vidb->hdr = buf + ubi->vid_hdr_shift;
1083 }
1084 
1085 /**
1086  * ubi_init_vid_buf - Allocate a VID buffer
1087  * @ubi: the UBI device
1088  * @gfp_flags: GFP flags to use for the allocation
1089  */
1090 static inline struct ubi_vid_io_buf *
1091 ubi_alloc_vid_buf(const struct ubi_device *ubi, gfp_t gfp_flags)
1092 {
1093 	struct ubi_vid_io_buf *vidb;
1094 	void *buf;
1095 
1096 	vidb = kzalloc(sizeof(*vidb), gfp_flags);
1097 	if (!vidb)
1098 		return NULL;
1099 
1100 	buf = kmalloc(ubi->vid_hdr_alsize, gfp_flags);
1101 	if (!buf) {
1102 		kfree(vidb);
1103 		return NULL;
1104 	}
1105 
1106 	ubi_init_vid_buf(ubi, vidb, buf);
1107 
1108 	return vidb;
1109 }
1110 
1111 /**
1112  * ubi_free_vid_buf - Free a VID buffer
1113  * @vidb: the VID buffer to free
1114  */
1115 static inline void ubi_free_vid_buf(struct ubi_vid_io_buf *vidb)
1116 {
1117 	if (!vidb)
1118 		return;
1119 
1120 	kfree(vidb->buffer);
1121 	kfree(vidb);
1122 }
1123 
1124 /**
1125  * ubi_get_vid_hdr - Get the VID header attached to a VID buffer
1126  * @vidb: VID buffer
1127  */
1128 static inline struct ubi_vid_hdr *ubi_get_vid_hdr(struct ubi_vid_io_buf *vidb)
1129 {
1130 	return vidb->hdr;
1131 }
1132 
1133 /*
1134  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1135  * the beginning of the logical eraseblock, not to the beginning of the
1136  * physical eraseblock.
1137  */
1138 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1139 				   int pnum, int offset, int len)
1140 {
1141 	ubi_assert(offset >= 0);
1142 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1143 }
1144 
1145 /*
1146  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1147  * the beginning of the logical eraseblock, not to the beginning of the
1148  * physical eraseblock.
1149  */
1150 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1151 				    int pnum, int offset, int len)
1152 {
1153 	ubi_assert(offset >= 0);
1154 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1155 }
1156 
1157 /**
1158  * ubi_ro_mode - switch to read-only mode.
1159  * @ubi: UBI device description object
1160  */
1161 static inline void ubi_ro_mode(struct ubi_device *ubi)
1162 {
1163 	if (!ubi->ro_mode) {
1164 		ubi->ro_mode = 1;
1165 		ubi_warn(ubi, "switch to read-only mode");
1166 		dump_stack();
1167 	}
1168 }
1169 
1170 /**
1171  * vol_id2idx - get table index by volume ID.
1172  * @ubi: UBI device description object
1173  * @vol_id: volume ID
1174  */
1175 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1176 {
1177 	if (vol_id >= UBI_INTERNAL_VOL_START)
1178 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1179 	else
1180 		return vol_id;
1181 }
1182 
1183 /**
1184  * idx2vol_id - get volume ID by table index.
1185  * @ubi: UBI device description object
1186  * @idx: table index
1187  */
1188 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1189 {
1190 	if (idx >= ubi->vtbl_slots)
1191 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1192 	else
1193 		return idx;
1194 }
1195 
1196 /**
1197  * ubi_is_fm_vol - check whether a volume ID is a Fastmap volume.
1198  * @vol_id: volume ID
1199  */
1200 static inline bool ubi_is_fm_vol(int vol_id)
1201 {
1202 	switch (vol_id) {
1203 		case UBI_FM_SB_VOLUME_ID:
1204 		case UBI_FM_DATA_VOLUME_ID:
1205 		return true;
1206 	}
1207 
1208 	return false;
1209 }
1210 
1211 /**
1212  * ubi_find_fm_block - check whether a PEB is part of the current Fastmap.
1213  * @ubi: UBI device description object
1214  * @pnum: physical eraseblock to look for
1215  *
1216  * This function returns a wear leveling object if @pnum relates to the current
1217  * fastmap, @NULL otherwise.
1218  */
1219 static inline struct ubi_wl_entry *ubi_find_fm_block(const struct ubi_device *ubi,
1220 						     int pnum)
1221 {
1222 	int i;
1223 
1224 	if (ubi->fm) {
1225 		for (i = 0; i < ubi->fm->used_blocks; i++) {
1226 			if (ubi->fm->e[i]->pnum == pnum)
1227 				return ubi->fm->e[i];
1228 		}
1229 	}
1230 
1231 	return NULL;
1232 }
1233 
1234 #endif /* !__UBI_UBI_H__ */
1235