xref: /linux/drivers/mtd/ubi/ubi.h (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
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  * struct ubi_vid_io_buf - VID buffer used to read/write VID info to/from the
150  *			   flash.
151  * @hdr: a pointer to the VID header stored in buffer
152  * @buffer: underlying buffer
153  */
154 struct ubi_vid_io_buf {
155 	struct ubi_vid_hdr *hdr;
156 	void *buffer;
157 };
158 
159 /**
160  * struct ubi_wl_entry - wear-leveling entry.
161  * @u.rb: link in the corresponding (free/used) RB-tree
162  * @u.list: link in the protection queue
163  * @ec: erase counter
164  * @pnum: physical eraseblock number
165  *
166  * This data structure is used in the WL sub-system. Each physical eraseblock
167  * has a corresponding &struct wl_entry object which may be kept in different
168  * RB-trees. See WL sub-system for details.
169  */
170 struct ubi_wl_entry {
171 	union {
172 		struct rb_node rb;
173 		struct list_head list;
174 	} u;
175 	int ec;
176 	int pnum;
177 };
178 
179 /**
180  * struct ubi_ltree_entry - an entry in the lock tree.
181  * @rb: links RB-tree nodes
182  * @vol_id: volume ID of the locked logical eraseblock
183  * @lnum: locked logical eraseblock number
184  * @users: how many tasks are using this logical eraseblock or wait for it
185  * @mutex: read/write mutex to implement read/write access serialization to
186  *         the (@vol_id, @lnum) logical eraseblock
187  *
188  * This data structure is used in the EBA sub-system to implement per-LEB
189  * locking. When a logical eraseblock is being locked - corresponding
190  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
191  * See EBA sub-system for details.
192  */
193 struct ubi_ltree_entry {
194 	struct rb_node rb;
195 	int vol_id;
196 	int lnum;
197 	int users;
198 	struct rw_semaphore mutex;
199 };
200 
201 /**
202  * struct ubi_rename_entry - volume re-name description data structure.
203  * @new_name_len: new volume name length
204  * @new_name: new volume name
205  * @remove: if not zero, this volume should be removed, not re-named
206  * @desc: descriptor of the volume
207  * @list: links re-name entries into a list
208  *
209  * This data structure is utilized in the multiple volume re-name code. Namely,
210  * UBI first creates a list of &struct ubi_rename_entry objects from the
211  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
212  * the job.
213  */
214 struct ubi_rename_entry {
215 	int new_name_len;
216 	char new_name[UBI_VOL_NAME_MAX + 1];
217 	int remove;
218 	struct ubi_volume_desc *desc;
219 	struct list_head list;
220 };
221 
222 struct ubi_volume_desc;
223 
224 /**
225  * struct ubi_fastmap_layout - in-memory fastmap data structure.
226  * @e: PEBs used by the current fastmap
227  * @to_be_tortured: if non-zero tortured this PEB
228  * @used_blocks: number of used PEBs
229  * @max_pool_size: maximal size of the user pool
230  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
231  */
232 struct ubi_fastmap_layout {
233 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
234 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
235 	int used_blocks;
236 	int max_pool_size;
237 	int max_wl_pool_size;
238 };
239 
240 /**
241  * struct ubi_fm_pool - in-memory fastmap pool
242  * @pebs: PEBs in this pool
243  * @used: number of used PEBs
244  * @size: total number of PEBs in this pool
245  * @max_size: maximal size of the pool
246  *
247  * A pool gets filled with up to max_size.
248  * If all PEBs within the pool are used a new fastmap will be written
249  * to the flash and the pool gets refilled with empty PEBs.
250  *
251  */
252 struct ubi_fm_pool {
253 	int pebs[UBI_FM_MAX_POOL_SIZE];
254 	int used;
255 	int size;
256 	int max_size;
257 };
258 
259 /**
260  * struct ubi_eba_leb_desc - EBA logical eraseblock descriptor
261  * @lnum: the logical eraseblock number
262  * @pnum: the physical eraseblock where the LEB can be found
263  *
264  * This structure is here to hide EBA's internal from other part of the
265  * UBI implementation.
266  *
267  * One can query the position of a LEB by calling ubi_eba_get_ldesc().
268  */
269 struct ubi_eba_leb_desc {
270 	int lnum;
271 	int pnum;
272 };
273 
274 /**
275  * struct ubi_volume - UBI volume description data structure.
276  * @dev: device object to make use of the Linux device model
277  * @cdev: character device object to create character device
278  * @ubi: reference to the UBI device description object
279  * @vol_id: volume ID
280  * @ref_count: volume reference count
281  * @readers: number of users holding this volume in read-only mode
282  * @writers: number of users holding this volume in read-write mode
283  * @exclusive: whether somebody holds this volume in exclusive mode
284  * @metaonly: whether somebody is altering only meta data of this volume
285  *
286  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
287  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
288  * @usable_leb_size: logical eraseblock size without padding
289  * @used_ebs: how many logical eraseblocks in this volume contain data
290  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
291  * @used_bytes: how many bytes of data this volume contains
292  * @alignment: volume alignment
293  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
294  *            satisfy the requested alignment
295  * @name_len: volume name length
296  * @name: volume name
297  *
298  * @upd_ebs: how many eraseblocks are expected to be updated
299  * @ch_lnum: LEB number which is being changing by the atomic LEB change
300  *           operation
301  * @upd_bytes: how many bytes are expected to be received for volume update or
302  *             atomic LEB change
303  * @upd_received: how many bytes were already received for volume update or
304  *                atomic LEB change
305  * @upd_buf: update buffer which is used to collect update data or data for
306  *           atomic LEB change
307  *
308  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
309  * @skip_check: %1 if CRC check of this static volume should be skipped.
310  *		Directly reflects the presence of the
311  *		%UBI_VTBL_SKIP_CRC_CHECK_FLG flag in the vtbl entry
312  * @checked: %1 if this static volume was checked
313  * @corrupted: %1 if the volume is corrupted (static volumes only)
314  * @upd_marker: %1 if the update marker is set for this volume
315  * @updating: %1 if the volume is being updated
316  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
317  * @direct_writes: %1 if direct writes are enabled for this volume
318  *
319  * @checkmap: bitmap to remember which PEB->LEB mappings got checked,
320  *            protected by UBI LEB lock tree.
321  *
322  * The @corrupted field indicates that the volume's contents is corrupted.
323  * Since UBI protects only static volumes, this field is not relevant to
324  * dynamic volumes - it is user's responsibility to assure their data
325  * integrity.
326  *
327  * The @upd_marker flag indicates that this volume is either being updated at
328  * the moment or is damaged because of an unclean reboot.
329  */
330 struct ubi_volume {
331 	struct device dev;
332 	struct cdev cdev;
333 	struct ubi_device *ubi;
334 	int vol_id;
335 	int ref_count;
336 	int readers;
337 	int writers;
338 	int exclusive;
339 	int metaonly;
340 	bool is_dead;
341 
342 	int reserved_pebs;
343 	int vol_type;
344 	int usable_leb_size;
345 	int used_ebs;
346 	int last_eb_bytes;
347 	long long used_bytes;
348 	int alignment;
349 	int data_pad;
350 	int name_len;
351 	char name[UBI_VOL_NAME_MAX + 1];
352 
353 	int upd_ebs;
354 	int ch_lnum;
355 	long long upd_bytes;
356 	long long upd_received;
357 	void *upd_buf;
358 
359 	struct ubi_eba_table *eba_tbl;
360 	unsigned int skip_check:1;
361 	unsigned int checked:1;
362 	unsigned int corrupted:1;
363 	unsigned int upd_marker:1;
364 	unsigned int updating:1;
365 	unsigned int changing_leb:1;
366 	unsigned int direct_writes:1;
367 
368 #ifdef CONFIG_MTD_UBI_FASTMAP
369 	unsigned long *checkmap;
370 #endif
371 };
372 
373 /**
374  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
375  * @vol: reference to the corresponding volume description object
376  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
377  * or %UBI_METAONLY)
378  */
379 struct ubi_volume_desc {
380 	struct ubi_volume *vol;
381 	int mode;
382 };
383 
384 /**
385  * struct ubi_debug_info - debugging information for an UBI device.
386  *
387  * @chk_gen: if UBI general extra checks are enabled
388  * @chk_io: if UBI I/O extra checks are enabled
389  * @chk_fastmap: if UBI fastmap extra checks are enabled
390  * @disable_bgt: disable the background task for testing purposes
391  * @emulate_bitflips: emulate bit-flips for testing purposes
392  * @emulate_io_failures: emulate write/erase failures for testing purposes
393  * @emulate_power_cut: emulate power cut for testing purposes
394  * @power_cut_counter: count down for writes left until emulated power cut
395  * @power_cut_min: minimum number of writes before emulating a power cut
396  * @power_cut_max: maximum number of writes until emulating a power cut
397  * @emulate_failures: emulate failures for testing purposes
398  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
399  * @dfs_dir: direntry object of the UBI device debugfs directory
400  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
401  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
402  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
403  * @dfs_disable_bgt: debugfs knob to disable the background task
404  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
405  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
406  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
407  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
408  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
409  * @dfs_emulate_failures: debugfs entry to control the fault injection type
410  */
411 struct ubi_debug_info {
412 	unsigned int chk_gen:1;
413 	unsigned int chk_io:1;
414 	unsigned int chk_fastmap:1;
415 	unsigned int disable_bgt:1;
416 	unsigned int emulate_bitflips:1;
417 	unsigned int emulate_io_failures:1;
418 	unsigned int emulate_power_cut:2;
419 	unsigned int power_cut_counter;
420 	unsigned int power_cut_min;
421 	unsigned int power_cut_max;
422 	unsigned int emulate_failures;
423 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
424 	struct dentry *dfs_dir;
425 	struct dentry *dfs_chk_gen;
426 	struct dentry *dfs_chk_io;
427 	struct dentry *dfs_chk_fastmap;
428 	struct dentry *dfs_disable_bgt;
429 	struct dentry *dfs_emulate_bitflips;
430 	struct dentry *dfs_emulate_io_failures;
431 	struct dentry *dfs_emulate_power_cut;
432 	struct dentry *dfs_power_cut_min;
433 	struct dentry *dfs_power_cut_max;
434 	struct dentry *dfs_emulate_failures;
435 };
436 
437 /**
438  * struct ubi_device - UBI device description structure
439  * @dev: UBI device object to use the Linux device model
440  * @cdev: character device object to create character device
441  * @ubi_num: UBI device number
442  * @ubi_name: UBI device name
443  * @vol_count: number of volumes in this UBI device
444  * @volumes: volumes of this UBI device
445  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
446  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
447  *                @vol->readers, @vol->writers, @vol->exclusive,
448  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
449  *                @vol->eba_tbl.
450  * @ref_count: count of references on the UBI device
451  * @image_seq: image sequence number recorded on EC headers
452  *
453  * @rsvd_pebs: count of reserved physical eraseblocks
454  * @avail_pebs: count of available physical eraseblocks
455  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
456  *                 handling
457  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
458  *
459  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
460  *                     of UBI initialization
461  * @vtbl_slots: how many slots are available in the volume table
462  * @vtbl_size: size of the volume table in bytes
463  * @vtbl: in-RAM volume table copy
464  * @device_mutex: protects on-flash volume table and serializes volume
465  *                creation, deletion, update, re-size, re-name and set
466  *                property
467  *
468  * @max_ec: current highest erase counter value
469  * @mean_ec: current mean erase counter value
470  *
471  * @global_sqnum: global sequence number
472  * @ltree_lock: protects the lock tree and @global_sqnum
473  * @ltree: the lock tree
474  * @alc_mutex: serializes "atomic LEB change" operations
475  *
476  * @fm_disabled: non-zero if fastmap is disabled (default)
477  * @fm: in-memory data structure of the currently used fastmap
478  * @fm_pool: in-memory data structure of the fastmap pool
479  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
480  *		sub-system
481  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
482  * that critical sections cannot be interrupted by ubi_update_fastmap()
483  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
484  * @fm_size: fastmap size in bytes
485  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
486  * @fm_work: fastmap work queue
487  * @fm_work_scheduled: non-zero if fastmap work was scheduled
488  * @fast_attach: non-zero if UBI was attached by fastmap
489  * @fm_anchor: The next anchor PEB to use for fastmap
490  * @fm_do_produce_anchor: If true produce an anchor PEB in wl
491  * @fm_pool_rsv_cnt: Number of reserved PEBs for filling pool/wl_pool
492  *
493  * @used: RB-tree of used physical eraseblocks
494  * @erroneous: RB-tree of erroneous used physical eraseblocks
495  * @free: RB-tree of free physical eraseblocks
496  * @free_count: Contains the number of elements in @free
497  * @scrub: RB-tree of physical eraseblocks which need scrubbing
498  * @pq: protection queue (contain physical eraseblocks which are temporarily
499  *      protected from the wear-leveling worker)
500  * @pq_head: protection queue head
501  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
502  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
503  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
504  *	     and @fm_wl_pool fields
505  * @move_mutex: serializes eraseblock moves
506  * @work_sem: used to wait for all the scheduled works to finish and prevent
507  * new works from being submitted
508  * @wl_scheduled: non-zero if the wear-leveling was scheduled
509  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
510  *             physical eraseblock
511  * @move_from: physical eraseblock from where the data is being moved
512  * @move_to: physical eraseblock where the data is being moved to
513  * @move_to_put: if the "to" PEB was put
514  * @works: list of pending works
515  * @works_count: count of pending works
516  * @bgt_thread: background thread description object
517  * @thread_enabled: if the background thread is enabled
518  * @bgt_name: background thread name
519  *
520  * @flash_size: underlying MTD device size (in bytes)
521  * @peb_count: count of physical eraseblocks on the MTD device
522  * @peb_size: physical eraseblock size
523  * @bad_peb_limit: top limit of expected bad physical eraseblocks
524  * @bad_peb_count: count of bad physical eraseblocks
525  * @good_peb_count: count of good physical eraseblocks
526  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
527  *                  used by UBI)
528  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
529  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
530  * @min_io_size: minimal input/output unit size of the underlying MTD device
531  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
532  * @ro_mode: if the UBI device is in read-only mode
533  * @leb_size: logical eraseblock size
534  * @leb_start: starting offset of logical eraseblocks within physical
535  *             eraseblocks
536  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
537  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
538  * @vid_hdr_offset: starting offset of the volume identifier header (might be
539  *                  unaligned)
540  * @vid_hdr_aloffset: starting offset of the VID header aligned to
541  *                    @hdrs_min_io_size
542  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
543  * @bad_allowed: whether the MTD device admits bad physical eraseblocks or not
544  * @nor_flash: non-zero if working on top of NOR flash
545  * @max_write_size: maximum amount of bytes the underlying flash can write at a
546  *                  time (MTD write buffer size)
547  * @mtd: MTD device descriptor
548  *
549  * @peb_buf: a buffer of PEB size used for different purposes
550  * @buf_mutex: protects @peb_buf
551  * @ckvol_mutex: serializes static volume checking when opening
552  *
553  * @dbg: debugging information for this UBI device
554  */
555 struct ubi_device {
556 	struct cdev cdev;
557 	struct device dev;
558 	int ubi_num;
559 	char ubi_name[sizeof(UBI_NAME_STR)+5];
560 	int vol_count;
561 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
562 	spinlock_t volumes_lock;
563 	int ref_count;
564 	int image_seq;
565 	bool is_dead;
566 
567 	int rsvd_pebs;
568 	int avail_pebs;
569 	int beb_rsvd_pebs;
570 	int beb_rsvd_level;
571 	int bad_peb_limit;
572 
573 	int autoresize_vol_id;
574 	int vtbl_slots;
575 	int vtbl_size;
576 	struct ubi_vtbl_record *vtbl;
577 	struct mutex device_mutex;
578 
579 	int max_ec;
580 	/* Note, mean_ec is not updated run-time - should be fixed */
581 	int mean_ec;
582 
583 	/* EBA sub-system's stuff */
584 	unsigned long long global_sqnum;
585 	spinlock_t ltree_lock;
586 	struct rb_root ltree;
587 	struct mutex alc_mutex;
588 
589 	/* Fastmap stuff */
590 	int fm_disabled;
591 	struct ubi_fastmap_layout *fm;
592 	struct ubi_fm_pool fm_pool;
593 	struct ubi_fm_pool fm_wl_pool;
594 	struct rw_semaphore fm_eba_sem;
595 	struct rw_semaphore fm_protect;
596 	void *fm_buf;
597 	size_t fm_size;
598 	struct work_struct fm_work;
599 	int fm_work_scheduled;
600 	int fast_attach;
601 	struct ubi_wl_entry *fm_anchor;
602 	int fm_do_produce_anchor;
603 	int fm_pool_rsv_cnt;
604 
605 	/* Wear-leveling sub-system's stuff */
606 	struct rb_root used;
607 	struct rb_root erroneous;
608 	struct rb_root free;
609 	int free_count;
610 	struct rb_root scrub;
611 	struct list_head pq[UBI_PROT_QUEUE_LEN];
612 	int pq_head;
613 	spinlock_t wl_lock;
614 	struct mutex move_mutex;
615 	struct rw_semaphore work_sem;
616 	int wl_scheduled;
617 	struct ubi_wl_entry **lookuptbl;
618 	struct ubi_wl_entry *move_from;
619 	struct ubi_wl_entry *move_to;
620 	int move_to_put;
621 	struct list_head works;
622 	int works_count;
623 	struct task_struct *bgt_thread;
624 	int thread_enabled;
625 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
626 
627 	/* I/O sub-system's stuff */
628 	long long flash_size;
629 	int peb_count;
630 	int peb_size;
631 	int bad_peb_count;
632 	int good_peb_count;
633 	int corr_peb_count;
634 	int erroneous_peb_count;
635 	int max_erroneous;
636 	int min_io_size;
637 	int hdrs_min_io_size;
638 	int ro_mode;
639 	int leb_size;
640 	int leb_start;
641 	int ec_hdr_alsize;
642 	int vid_hdr_alsize;
643 	int vid_hdr_offset;
644 	int vid_hdr_aloffset;
645 	int vid_hdr_shift;
646 	unsigned int bad_allowed:1;
647 	unsigned int nor_flash:1;
648 	int max_write_size;
649 	struct mtd_info *mtd;
650 
651 	void *peb_buf;
652 	struct mutex buf_mutex;
653 	struct mutex ckvol_mutex;
654 
655 	struct ubi_debug_info dbg;
656 };
657 
658 /**
659  * struct ubi_ainf_peb - attach information about a physical eraseblock.
660  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
661  * @pnum: physical eraseblock number
662  * @vol_id: ID of the volume this LEB belongs to
663  * @lnum: logical eraseblock number
664  * @scrub: if this physical eraseblock needs scrubbing
665  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
666  * @sqnum: sequence number
667  * @u: unions RB-tree or @list links
668  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
669  * @u.list: link in one of the eraseblock lists
670  *
671  * One object of this type is allocated for each physical eraseblock when
672  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
673  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
674  */
675 struct ubi_ainf_peb {
676 	int ec;
677 	int pnum;
678 	int vol_id;
679 	int lnum;
680 	unsigned int scrub:1;
681 	unsigned int copy_flag:1;
682 	unsigned long long sqnum;
683 	union {
684 		struct rb_node rb;
685 		struct list_head list;
686 	} u;
687 };
688 
689 /**
690  * struct ubi_ainf_volume - attaching information about a volume.
691  * @vol_id: volume ID
692  * @highest_lnum: highest logical eraseblock number in this volume
693  * @leb_count: number of logical eraseblocks in this volume
694  * @vol_type: volume type
695  * @used_ebs: number of used logical eraseblocks in this volume (only for
696  *            static volumes)
697  * @last_data_size: amount of data in the last logical eraseblock of this
698  *                  volume (always equivalent to the usable logical eraseblock
699  *                  size in case of dynamic volumes)
700  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
701  *            are not used (due to volume alignment)
702  * @compat: compatibility flags of this volume
703  * @rb: link in the volume RB-tree
704  * @root: root of the RB-tree containing all the eraseblock belonging to this
705  *        volume (&struct ubi_ainf_peb objects)
706  *
707  * One object of this type is allocated for each volume when attaching an MTD
708  * device.
709  */
710 struct ubi_ainf_volume {
711 	int vol_id;
712 	int highest_lnum;
713 	int leb_count;
714 	int vol_type;
715 	int used_ebs;
716 	int last_data_size;
717 	int data_pad;
718 	int compat;
719 	struct rb_node rb;
720 	struct rb_root root;
721 };
722 
723 /**
724  * struct ubi_attach_info - MTD device attaching information.
725  * @volumes: root of the volume RB-tree
726  * @corr: list of corrupted physical eraseblocks
727  * @free: list of free physical eraseblocks
728  * @erase: list of physical eraseblocks which have to be erased
729  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
730  *         those belonging to "preserve"-compatible internal volumes)
731  * @fastmap: list of physical eraseblocks which relate to fastmap (e.g.,
732  *           eraseblocks of the current and not yet erased old fastmap blocks)
733  * @corr_peb_count: count of PEBs in the @corr list
734  * @empty_peb_count: count of PEBs which are presumably empty (contain only
735  *                   0xFF bytes)
736  * @alien_peb_count: count of PEBs in the @alien list
737  * @bad_peb_count: count of bad physical eraseblocks
738  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
739  *                       as bad yet, but which look like bad
740  * @vols_found: number of volumes found
741  * @highest_vol_id: highest volume ID
742  * @is_empty: flag indicating whether the MTD device is empty or not
743  * @force_full_scan: flag indicating whether we need to do a full scan and drop
744 		     all existing Fastmap data structures
745  * @min_ec: lowest erase counter value
746  * @max_ec: highest erase counter value
747  * @max_sqnum: highest sequence number value
748  * @mean_ec: mean erase counter value
749  * @ec_sum: a temporary variable used when calculating @mean_ec
750  * @ec_count: a temporary variable used when calculating @mean_ec
751  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
752  * @ech: temporary EC header. Only available during scan
753  * @vidh: temporary VID buffer. Only available during scan
754  *
755  * This data structure contains the result of attaching an MTD device and may
756  * be used by other UBI sub-systems to build final UBI data structures, further
757  * error-recovery and so on.
758  */
759 struct ubi_attach_info {
760 	struct rb_root volumes;
761 	struct list_head corr;
762 	struct list_head free;
763 	struct list_head erase;
764 	struct list_head alien;
765 	struct list_head fastmap;
766 	int corr_peb_count;
767 	int empty_peb_count;
768 	int alien_peb_count;
769 	int bad_peb_count;
770 	int maybe_bad_peb_count;
771 	int vols_found;
772 	int highest_vol_id;
773 	int is_empty;
774 	int force_full_scan;
775 	int min_ec;
776 	int max_ec;
777 	unsigned long long max_sqnum;
778 	int mean_ec;
779 	uint64_t ec_sum;
780 	int ec_count;
781 	struct kmem_cache *aeb_slab_cache;
782 	struct ubi_ec_hdr *ech;
783 	struct ubi_vid_io_buf *vidb;
784 };
785 
786 /**
787  * struct ubi_work - UBI work description data structure.
788  * @list: a link in the list of pending works
789  * @func: worker function
790  * @e: physical eraseblock to erase
791  * @vol_id: the volume ID on which this erasure is being performed
792  * @lnum: the logical eraseblock number
793  * @torture: if the physical eraseblock has to be tortured
794  *
795  * The @func pointer points to the worker function. If the @shutdown argument is
796  * not zero, the worker has to free the resources and exit immediately as the
797  * WL sub-system is shutting down.
798  * The worker has to return zero in case of success and a negative error code in
799  * case of failure.
800  */
801 struct ubi_work {
802 	struct list_head list;
803 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
804 	/* The below fields are only relevant to erasure works */
805 	struct ubi_wl_entry *e;
806 	int vol_id;
807 	int lnum;
808 	int torture;
809 };
810 
811 #include "debug.h"
812 
813 extern struct kmem_cache *ubi_wl_entry_slab;
814 extern const struct file_operations ubi_ctrl_cdev_operations;
815 extern const struct file_operations ubi_cdev_operations;
816 extern const struct file_operations ubi_vol_cdev_operations;
817 extern struct class ubi_class;
818 extern struct mutex ubi_devices_mutex;
819 extern struct blocking_notifier_head ubi_notifiers;
820 
821 /* attach.c */
822 struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
823 				   int ec);
824 void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb);
825 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
826 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
827 struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id);
828 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
829 				    int vol_id);
830 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
831 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
832 				       struct ubi_attach_info *ai);
833 int ubi_attach(struct ubi_device *ubi, int force_scan);
834 void ubi_destroy_ai(struct ubi_attach_info *ai);
835 
836 /* vtbl.c */
837 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
838 			   struct ubi_vtbl_record *vtbl_rec);
839 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
840 			    struct list_head *rename_list);
841 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
842 
843 /* vmt.c */
844 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
845 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
846 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
847 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
848 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
849 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
850 
851 /* upd.c */
852 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
853 		     long long bytes);
854 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
855 			 const void __user *buf, int count);
856 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
857 			 const struct ubi_leb_change_req *req);
858 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
859 			     const void __user *buf, int count);
860 
861 /* misc.c */
862 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
863 		      int length);
864 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
865 void ubi_update_reserved(struct ubi_device *ubi);
866 void ubi_calculate_reserved(struct ubi_device *ubi);
867 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
868 
869 static inline bool ubi_leb_valid(struct ubi_volume *vol, int lnum)
870 {
871 	return lnum >= 0 && lnum < vol->reserved_pebs;
872 }
873 
874 /* eba.c */
875 struct ubi_eba_table *ubi_eba_create_table(struct ubi_volume *vol,
876 					   int nentries);
877 void ubi_eba_destroy_table(struct ubi_eba_table *tbl);
878 void ubi_eba_copy_table(struct ubi_volume *vol, struct ubi_eba_table *dst,
879 			int nentries);
880 void ubi_eba_replace_table(struct ubi_volume *vol, struct ubi_eba_table *tbl);
881 void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
882 		       struct ubi_eba_leb_desc *ldesc);
883 bool ubi_eba_is_mapped(struct ubi_volume *vol, int lnum);
884 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
885 		      int lnum);
886 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
887 		     void *buf, int offset, int len, int check);
888 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
889 			struct ubi_sgl *sgl, int lnum, int offset, int len,
890 			int check);
891 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
892 		      const void *buf, int offset, int len);
893 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
894 			 int lnum, const void *buf, int len, int used_ebs);
895 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
896 			      int lnum, const void *buf, int len);
897 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
898 		     struct ubi_vid_io_buf *vidb);
899 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
900 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
901 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
902 		   struct ubi_attach_info *ai_scan);
903 
904 /* wl.c */
905 int ubi_sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture);
906 int ubi_wl_get_peb(struct ubi_device *ubi);
907 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
908 		   int pnum, int torture);
909 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
910 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
911 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
912 void ubi_wl_close(struct ubi_device *ubi);
913 int ubi_thread(void *u);
914 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
915 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
916 		      int lnum, int torture);
917 int ubi_is_erase_work(struct ubi_work *wrk);
918 void ubi_refill_pools_and_lock(struct ubi_device *ubi);
919 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
920 int ubi_bitflip_check(struct ubi_device *ubi, int pnum, int force_scrub);
921 
922 /* io.c */
923 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
924 		int len);
925 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
926 		 int len);
927 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
928 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
929 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
930 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
931 		       struct ubi_ec_hdr *ec_hdr, int verbose);
932 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
933 			struct ubi_ec_hdr *ec_hdr);
934 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
935 			struct ubi_vid_io_buf *vidb, int verbose);
936 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
937 			 struct ubi_vid_io_buf *vidb);
938 
939 /* build.c */
940 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
941 		       int vid_hdr_offset, int max_beb_per1024,
942 		       bool disable_fm, bool need_resv_pool);
943 int ubi_detach_mtd_dev(int ubi_num, int anyway);
944 struct ubi_device *ubi_get_device(int ubi_num);
945 void ubi_put_device(struct ubi_device *ubi);
946 struct ubi_device *ubi_get_by_major(int major);
947 int ubi_major2num(int major);
948 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
949 		      int ntype);
950 int ubi_notify_all(struct ubi_device *ubi, int ntype,
951 		   struct notifier_block *nb);
952 int ubi_enumerate_volumes(struct notifier_block *nb);
953 void ubi_free_all_volumes(struct ubi_device *ubi);
954 void ubi_free_internal_volumes(struct ubi_device *ubi);
955 
956 /* kapi.c */
957 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
958 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
959 			    struct ubi_volume_info *vi);
960 int ubi_get_num_by_path(const char *pathname, int *ubi_num, int *vol_id);
961 /* scan.c */
962 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
963 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
964 
965 /* fastmap.c */
966 #ifdef CONFIG_MTD_UBI_FASTMAP
967 size_t ubi_calc_fm_size(struct ubi_device *ubi);
968 int ubi_update_fastmap(struct ubi_device *ubi);
969 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
970 		     struct ubi_attach_info *scan_ai);
971 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count);
972 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol);
973 #else
974 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
975 static inline int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count) { return 0; }
976 static inline void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol) {}
977 #endif
978 
979 /* block.c */
980 #ifdef CONFIG_MTD_UBI_BLOCK
981 int ubiblock_init(void);
982 void ubiblock_exit(void);
983 int ubiblock_create(struct ubi_volume_info *vi);
984 int ubiblock_remove(struct ubi_volume_info *vi);
985 #else
986 static inline int ubiblock_init(void) { return 0; }
987 static inline void ubiblock_exit(void) {}
988 static inline int ubiblock_create(struct ubi_volume_info *vi)
989 {
990 	return -ENOSYS;
991 }
992 static inline int ubiblock_remove(struct ubi_volume_info *vi)
993 {
994 	return -ENOSYS;
995 }
996 #endif
997 
998 /*
999  * ubi_for_each_free_peb - walk the UBI free RB tree.
1000  * @ubi: UBI device description object
1001  * @e: a pointer to a ubi_wl_entry to use as cursor
1002  * @pos: a pointer to RB-tree entry type to use as a loop counter
1003  */
1004 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
1005 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
1006 
1007 /*
1008  * ubi_for_each_used_peb - walk the UBI used RB tree.
1009  * @ubi: UBI device description object
1010  * @e: a pointer to a ubi_wl_entry to use as cursor
1011  * @pos: a pointer to RB-tree entry type to use as a loop counter
1012  */
1013 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
1014 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
1015 
1016 /*
1017  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
1018  * @ubi: UBI device description object
1019  * @e: a pointer to a ubi_wl_entry to use as cursor
1020  * @pos: a pointer to RB-tree entry type to use as a loop counter
1021  */
1022 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
1023 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
1024 
1025 /*
1026  * ubi_for_each_protected_peb - walk the UBI protection queue.
1027  * @ubi: UBI device description object
1028  * @i: a integer used as counter
1029  * @e: a pointer to a ubi_wl_entry to use as cursor
1030  */
1031 #define ubi_for_each_protected_peb(ubi, i, e)	\
1032 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
1033 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
1034 
1035 /*
1036  * ubi_rb_for_each_entry - walk an RB-tree.
1037  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
1038  * @pos: a pointer to RB-tree entry type to use as a loop counter
1039  * @root: RB-tree's root
1040  * @member: the name of the 'struct rb_node' within the RB-tree entry
1041  */
1042 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
1043 	for (rb = rb_first(root),                                            \
1044 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
1045 	     rb;                                                             \
1046 	     rb = rb_next(rb),                                               \
1047 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
1048 
1049 /*
1050  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
1051  *
1052  * @av: volume attaching information
1053  * @aeb: attaching eraseblock information
1054  * @list: the list to move to
1055  */
1056 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
1057 					 struct ubi_ainf_peb *aeb,
1058 					 struct list_head *list)
1059 {
1060 		rb_erase(&aeb->u.rb, &av->root);
1061 		list_add_tail(&aeb->u.list, list);
1062 }
1063 
1064 /**
1065  * ubi_init_vid_buf - Initialize a VID buffer
1066  * @ubi: the UBI device
1067  * @vidb: the VID buffer to initialize
1068  * @buf: the underlying buffer
1069  */
1070 static inline void ubi_init_vid_buf(const struct ubi_device *ubi,
1071 				    struct ubi_vid_io_buf *vidb,
1072 				    void *buf)
1073 {
1074 	if (buf)
1075 		memset(buf, 0, ubi->vid_hdr_alsize);
1076 
1077 	vidb->buffer = buf;
1078 	vidb->hdr = buf + ubi->vid_hdr_shift;
1079 }
1080 
1081 /**
1082  * ubi_init_vid_buf - Allocate a VID buffer
1083  * @ubi: the UBI device
1084  * @gfp_flags: GFP flags to use for the allocation
1085  */
1086 static inline struct ubi_vid_io_buf *
1087 ubi_alloc_vid_buf(const struct ubi_device *ubi, gfp_t gfp_flags)
1088 {
1089 	struct ubi_vid_io_buf *vidb;
1090 	void *buf;
1091 
1092 	vidb = kzalloc(sizeof(*vidb), gfp_flags);
1093 	if (!vidb)
1094 		return NULL;
1095 
1096 	buf = kmalloc(ubi->vid_hdr_alsize, gfp_flags);
1097 	if (!buf) {
1098 		kfree(vidb);
1099 		return NULL;
1100 	}
1101 
1102 	ubi_init_vid_buf(ubi, vidb, buf);
1103 
1104 	return vidb;
1105 }
1106 
1107 /**
1108  * ubi_free_vid_buf - Free a VID buffer
1109  * @vidb: the VID buffer to free
1110  */
1111 static inline void ubi_free_vid_buf(struct ubi_vid_io_buf *vidb)
1112 {
1113 	if (!vidb)
1114 		return;
1115 
1116 	kfree(vidb->buffer);
1117 	kfree(vidb);
1118 }
1119 
1120 /**
1121  * ubi_get_vid_hdr - Get the VID header attached to a VID buffer
1122  * @vidb: VID buffer
1123  */
1124 static inline struct ubi_vid_hdr *ubi_get_vid_hdr(struct ubi_vid_io_buf *vidb)
1125 {
1126 	return vidb->hdr;
1127 }
1128 
1129 /**
1130  * ubi_ro_mode - switch to read-only mode.
1131  * @ubi: UBI device description object
1132  */
1133 static inline void ubi_ro_mode(struct ubi_device *ubi)
1134 {
1135 	if (!ubi->ro_mode) {
1136 		ubi->ro_mode = 1;
1137 		ubi_warn(ubi, "switch to read-only mode");
1138 		dump_stack();
1139 	}
1140 }
1141 
1142 /*
1143  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1144  * the beginning of the logical eraseblock, not to the beginning of the
1145  * physical eraseblock.
1146  */
1147 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1148 				   int pnum, int offset, int len)
1149 {
1150 	ubi_assert(offset >= 0);
1151 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1152 }
1153 
1154 /*
1155  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1156  * the beginning of the logical eraseblock, not to the beginning of the
1157  * physical eraseblock.
1158  */
1159 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1160 				    int pnum, int offset, int len)
1161 {
1162 	ubi_assert(offset >= 0);
1163 
1164 	if (ubi_dbg_power_cut(ubi, MASK_POWER_CUT_DATA)) {
1165 		ubi_warn(ubi, "XXXXX emulating a power cut when writing data XXXXX");
1166 		ubi_ro_mode(ubi);
1167 		return -EROFS;
1168 	}
1169 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1170 }
1171 
1172 /**
1173  * vol_id2idx - get table index by volume ID.
1174  * @ubi: UBI device description object
1175  * @vol_id: volume ID
1176  */
1177 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1178 {
1179 	if (vol_id >= UBI_INTERNAL_VOL_START)
1180 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1181 	else
1182 		return vol_id;
1183 }
1184 
1185 /**
1186  * idx2vol_id - get volume ID by table index.
1187  * @ubi: UBI device description object
1188  * @idx: table index
1189  */
1190 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1191 {
1192 	if (idx >= ubi->vtbl_slots)
1193 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1194 	else
1195 		return idx;
1196 }
1197 
1198 /**
1199  * ubi_is_fm_vol - check whether a volume ID is a Fastmap volume.
1200  * @vol_id: volume ID
1201  */
1202 static inline bool ubi_is_fm_vol(int vol_id)
1203 {
1204 	switch (vol_id) {
1205 		case UBI_FM_SB_VOLUME_ID:
1206 		case UBI_FM_DATA_VOLUME_ID:
1207 		return true;
1208 	}
1209 
1210 	return false;
1211 }
1212 
1213 /**
1214  * ubi_find_fm_block - check whether a PEB is part of the current Fastmap.
1215  * @ubi: UBI device description object
1216  * @pnum: physical eraseblock to look for
1217  *
1218  * This function returns a wear leveling object if @pnum relates to the current
1219  * fastmap, @NULL otherwise.
1220  */
1221 static inline struct ubi_wl_entry *ubi_find_fm_block(const struct ubi_device *ubi,
1222 						     int pnum)
1223 {
1224 	int i;
1225 
1226 	if (ubi->fm) {
1227 		for (i = 0; i < ubi->fm->used_blocks; i++) {
1228 			if (ubi->fm->e[i]->pnum == pnum)
1229 				return ubi->fm->e[i];
1230 		}
1231 	}
1232 
1233 	return NULL;
1234 }
1235 
1236 #endif /* !__UBI_UBI_H__ */
1237