xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 93f5715e)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2006, 2007
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  *
19  * Author: Artem Bityutskiy (Битюцкий Артём)
20  */
21 
22 #ifndef __UBI_UBI_H__
23 #define __UBI_UBI_H__
24 
25 #include <linux/types.h>
26 #include <linux/list.h>
27 #include <linux/rbtree.h>
28 #include <linux/sched.h>
29 #include <linux/wait.h>
30 #include <linux/mutex.h>
31 #include <linux/rwsem.h>
32 #include <linux/spinlock.h>
33 #include <linux/fs.h>
34 #include <linux/cdev.h>
35 #include <linux/device.h>
36 #include <linux/slab.h>
37 #include <linux/string.h>
38 #include <linux/vmalloc.h>
39 #include <linux/notifier.h>
40 #include <linux/mtd/mtd.h>
41 #include <linux/mtd/ubi.h>
42 #include <asm/pgtable.h>
43 
44 #include "ubi-media.h"
45 
46 /* Maximum number of supported UBI devices */
47 #define UBI_MAX_DEVICES 32
48 
49 /* UBI name used for character devices, sysfs, etc */
50 #define UBI_NAME_STR "ubi"
51 
52 struct ubi_device;
53 
54 /* Normal UBI messages */
55 __printf(2, 3)
56 void ubi_msg(const struct ubi_device *ubi, const char *fmt, ...);
57 
58 /* UBI warning messages */
59 __printf(2, 3)
60 void ubi_warn(const struct ubi_device *ubi, const char *fmt, ...);
61 
62 /* UBI error messages */
63 __printf(2, 3)
64 void ubi_err(const struct ubi_device *ubi, const char *fmt, ...);
65 
66 /* Background thread name pattern */
67 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
68 
69 /*
70  * This marker in the EBA table means that the LEB is um-mapped.
71  * NOTE! It has to have the same value as %UBI_ALL.
72  */
73 #define UBI_LEB_UNMAPPED -1
74 
75 /*
76  * In case of errors, UBI tries to repeat the operation several times before
77  * returning error. The below constant defines how many times UBI re-tries.
78  */
79 #define UBI_IO_RETRIES 3
80 
81 /*
82  * Length of the protection queue. The length is effectively equivalent to the
83  * number of (global) erase cycles PEBs are protected from the wear-leveling
84  * worker.
85  */
86 #define UBI_PROT_QUEUE_LEN 10
87 
88 /* The volume ID/LEB number/erase counter is unknown */
89 #define UBI_UNKNOWN -1
90 
91 /*
92  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
93  * + 2 for the number plus 1 for the trailing zero byte.
94  */
95 #define UBI_DFS_DIR_NAME "ubi%d"
96 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
97 
98 /*
99  * Error codes returned by the I/O sub-system.
100  *
101  * UBI_IO_FF: the read region of flash contains only 0xFFs
102  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
103  *                     integrity error reported by the MTD driver
104  *                     (uncorrectable ECC error in case of NAND)
105  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
106  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
107  *                         data integrity error reported by the MTD driver
108  *                         (uncorrectable ECC error in case of NAND)
109  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
110  *
111  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
112  * be or'ed with other error code. But this is a big change because there are
113  * may callers, so it does not worth the risk of introducing a bug
114  */
115 enum {
116 	UBI_IO_FF = 1,
117 	UBI_IO_FF_BITFLIPS,
118 	UBI_IO_BAD_HDR,
119 	UBI_IO_BAD_HDR_EBADMSG,
120 	UBI_IO_BITFLIPS,
121 };
122 
123 /*
124  * Return codes of the 'ubi_eba_copy_leb()' function.
125  *
126  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
127  *                   PEB was put meanwhile, or there is I/O on the source PEB
128  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
129  *                     PEB
130  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
131  *                     PEB
132  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
133  *                     PEB
134  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
135  *                       target PEB
136  * MOVE_RETRY: retry scrubbing the PEB
137  */
138 enum {
139 	MOVE_CANCEL_RACE = 1,
140 	MOVE_SOURCE_RD_ERR,
141 	MOVE_TARGET_RD_ERR,
142 	MOVE_TARGET_WR_ERR,
143 	MOVE_TARGET_BITFLIPS,
144 	MOVE_RETRY,
145 };
146 
147 /*
148  * Return codes of the fastmap sub-system
149  *
150  * UBI_NO_FASTMAP: No fastmap super block was found
151  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
152  */
153 enum {
154 	UBI_NO_FASTMAP = 1,
155 	UBI_BAD_FASTMAP,
156 };
157 
158 /*
159  * Flags for emulate_power_cut in ubi_debug_info
160  *
161  * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
162  * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
163  */
164 enum {
165 	POWER_CUT_EC_WRITE = 0x01,
166 	POWER_CUT_VID_WRITE = 0x02,
167 };
168 
169 /**
170  * struct ubi_vid_io_buf - VID buffer used to read/write VID info to/from the
171  *			   flash.
172  * @hdr: a pointer to the VID header stored in buffer
173  * @buffer: underlying buffer
174  */
175 struct ubi_vid_io_buf {
176 	struct ubi_vid_hdr *hdr;
177 	void *buffer;
178 };
179 
180 /**
181  * struct ubi_wl_entry - wear-leveling entry.
182  * @u.rb: link in the corresponding (free/used) RB-tree
183  * @u.list: link in the protection queue
184  * @ec: erase counter
185  * @pnum: physical eraseblock number
186  *
187  * This data structure is used in the WL sub-system. Each physical eraseblock
188  * has a corresponding &struct wl_entry object which may be kept in different
189  * RB-trees. See WL sub-system for details.
190  */
191 struct ubi_wl_entry {
192 	union {
193 		struct rb_node rb;
194 		struct list_head list;
195 	} u;
196 	int ec;
197 	int pnum;
198 };
199 
200 /**
201  * struct ubi_ltree_entry - an entry in the lock tree.
202  * @rb: links RB-tree nodes
203  * @vol_id: volume ID of the locked logical eraseblock
204  * @lnum: locked logical eraseblock number
205  * @users: how many tasks are using this logical eraseblock or wait for it
206  * @mutex: read/write mutex to implement read/write access serialization to
207  *         the (@vol_id, @lnum) logical eraseblock
208  *
209  * This data structure is used in the EBA sub-system to implement per-LEB
210  * locking. When a logical eraseblock is being locked - corresponding
211  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
212  * See EBA sub-system for details.
213  */
214 struct ubi_ltree_entry {
215 	struct rb_node rb;
216 	int vol_id;
217 	int lnum;
218 	int users;
219 	struct rw_semaphore mutex;
220 };
221 
222 /**
223  * struct ubi_rename_entry - volume re-name description data structure.
224  * @new_name_len: new volume name length
225  * @new_name: new volume name
226  * @remove: if not zero, this volume should be removed, not re-named
227  * @desc: descriptor of the volume
228  * @list: links re-name entries into a list
229  *
230  * This data structure is utilized in the multiple volume re-name code. Namely,
231  * UBI first creates a list of &struct ubi_rename_entry objects from the
232  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
233  * the job.
234  */
235 struct ubi_rename_entry {
236 	int new_name_len;
237 	char new_name[UBI_VOL_NAME_MAX + 1];
238 	int remove;
239 	struct ubi_volume_desc *desc;
240 	struct list_head list;
241 };
242 
243 struct ubi_volume_desc;
244 
245 /**
246  * struct ubi_fastmap_layout - in-memory fastmap data structure.
247  * @e: PEBs used by the current fastmap
248  * @to_be_tortured: if non-zero tortured this PEB
249  * @used_blocks: number of used PEBs
250  * @max_pool_size: maximal size of the user pool
251  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
252  */
253 struct ubi_fastmap_layout {
254 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
255 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
256 	int used_blocks;
257 	int max_pool_size;
258 	int max_wl_pool_size;
259 };
260 
261 /**
262  * struct ubi_fm_pool - in-memory fastmap pool
263  * @pebs: PEBs in this pool
264  * @used: number of used PEBs
265  * @size: total number of PEBs in this pool
266  * @max_size: maximal size of the pool
267  *
268  * A pool gets filled with up to max_size.
269  * If all PEBs within the pool are used a new fastmap will be written
270  * to the flash and the pool gets refilled with empty PEBs.
271  *
272  */
273 struct ubi_fm_pool {
274 	int pebs[UBI_FM_MAX_POOL_SIZE];
275 	int used;
276 	int size;
277 	int max_size;
278 };
279 
280 /**
281  * struct ubi_eba_leb_desc - EBA logical eraseblock descriptor
282  * @lnum: the logical eraseblock number
283  * @pnum: the physical eraseblock where the LEB can be found
284  *
285  * This structure is here to hide EBA's internal from other part of the
286  * UBI implementation.
287  *
288  * One can query the position of a LEB by calling ubi_eba_get_ldesc().
289  */
290 struct ubi_eba_leb_desc {
291 	int lnum;
292 	int pnum;
293 };
294 
295 /**
296  * struct ubi_volume - UBI volume description data structure.
297  * @dev: device object to make use of the the Linux device model
298  * @cdev: character device object to create character device
299  * @ubi: reference to the UBI device description object
300  * @vol_id: volume ID
301  * @ref_count: volume reference count
302  * @readers: number of users holding this volume in read-only mode
303  * @writers: number of users holding this volume in read-write mode
304  * @exclusive: whether somebody holds this volume in exclusive mode
305  * @metaonly: whether somebody is altering only meta data of this volume
306  *
307  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
308  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
309  * @usable_leb_size: logical eraseblock size without padding
310  * @used_ebs: how many logical eraseblocks in this volume contain data
311  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
312  * @used_bytes: how many bytes of data this volume contains
313  * @alignment: volume alignment
314  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
315  *            satisfy the requested alignment
316  * @name_len: volume name length
317  * @name: volume name
318  *
319  * @upd_ebs: how many eraseblocks are expected to be updated
320  * @ch_lnum: LEB number which is being changing by the atomic LEB change
321  *           operation
322  * @upd_bytes: how many bytes are expected to be received for volume update or
323  *             atomic LEB change
324  * @upd_received: how many bytes were already received for volume update or
325  *                atomic LEB change
326  * @upd_buf: update buffer which is used to collect update data or data for
327  *           atomic LEB change
328  *
329  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
330  * @skip_check: %1 if CRC check of this static volume should be skipped.
331  *		Directly reflects the presence of the
332  *		%UBI_VTBL_SKIP_CRC_CHECK_FLG flag in the vtbl entry
333  * @checked: %1 if this static volume was checked
334  * @corrupted: %1 if the volume is corrupted (static volumes only)
335  * @upd_marker: %1 if the update marker is set for this volume
336  * @updating: %1 if the volume is being updated
337  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
338  * @direct_writes: %1 if direct writes are enabled for this volume
339  *
340  * @checkmap: bitmap to remember which PEB->LEB mappings got checked,
341  *            protected by UBI LEB lock tree.
342  *
343  * The @corrupted field indicates that the volume's contents is corrupted.
344  * Since UBI protects only static volumes, this field is not relevant to
345  * dynamic volumes - it is user's responsibility to assure their data
346  * integrity.
347  *
348  * The @upd_marker flag indicates that this volume is either being updated at
349  * the moment or is damaged because of an unclean reboot.
350  */
351 struct ubi_volume {
352 	struct device dev;
353 	struct cdev cdev;
354 	struct ubi_device *ubi;
355 	int vol_id;
356 	int ref_count;
357 	int readers;
358 	int writers;
359 	int exclusive;
360 	int metaonly;
361 
362 	int reserved_pebs;
363 	int vol_type;
364 	int usable_leb_size;
365 	int used_ebs;
366 	int last_eb_bytes;
367 	long long used_bytes;
368 	int alignment;
369 	int data_pad;
370 	int name_len;
371 	char name[UBI_VOL_NAME_MAX + 1];
372 
373 	int upd_ebs;
374 	int ch_lnum;
375 	long long upd_bytes;
376 	long long upd_received;
377 	void *upd_buf;
378 
379 	struct ubi_eba_table *eba_tbl;
380 	unsigned int skip_check:1;
381 	unsigned int checked:1;
382 	unsigned int corrupted:1;
383 	unsigned int upd_marker:1;
384 	unsigned int updating:1;
385 	unsigned int changing_leb:1;
386 	unsigned int direct_writes:1;
387 
388 #ifdef CONFIG_MTD_UBI_FASTMAP
389 	unsigned long *checkmap;
390 #endif
391 };
392 
393 /**
394  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
395  * @vol: reference to the corresponding volume description object
396  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
397  * or %UBI_METAONLY)
398  */
399 struct ubi_volume_desc {
400 	struct ubi_volume *vol;
401 	int mode;
402 };
403 
404 struct ubi_wl_entry;
405 
406 /**
407  * struct ubi_debug_info - debugging information for an UBI device.
408  *
409  * @chk_gen: if UBI general extra checks are enabled
410  * @chk_io: if UBI I/O extra checks are enabled
411  * @chk_fastmap: if UBI fastmap extra checks are enabled
412  * @disable_bgt: disable the background task for testing purposes
413  * @emulate_bitflips: emulate bit-flips for testing purposes
414  * @emulate_io_failures: emulate write/erase failures for testing purposes
415  * @emulate_power_cut: emulate power cut for testing purposes
416  * @power_cut_counter: count down for writes left until emulated power cut
417  * @power_cut_min: minimum number of writes before emulating a power cut
418  * @power_cut_max: maximum number of writes until emulating a power cut
419  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
420  * @dfs_dir: direntry object of the UBI device debugfs directory
421  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
422  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
423  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
424  * @dfs_disable_bgt: debugfs knob to disable the background task
425  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
426  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
427  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
428  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
429  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
430  */
431 struct ubi_debug_info {
432 	unsigned int chk_gen:1;
433 	unsigned int chk_io:1;
434 	unsigned int chk_fastmap:1;
435 	unsigned int disable_bgt:1;
436 	unsigned int emulate_bitflips:1;
437 	unsigned int emulate_io_failures:1;
438 	unsigned int emulate_power_cut:2;
439 	unsigned int power_cut_counter;
440 	unsigned int power_cut_min;
441 	unsigned int power_cut_max;
442 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
443 	struct dentry *dfs_dir;
444 	struct dentry *dfs_chk_gen;
445 	struct dentry *dfs_chk_io;
446 	struct dentry *dfs_chk_fastmap;
447 	struct dentry *dfs_disable_bgt;
448 	struct dentry *dfs_emulate_bitflips;
449 	struct dentry *dfs_emulate_io_failures;
450 	struct dentry *dfs_emulate_power_cut;
451 	struct dentry *dfs_power_cut_min;
452 	struct dentry *dfs_power_cut_max;
453 };
454 
455 /**
456  * struct ubi_device - UBI device description structure
457  * @dev: UBI device object to use the the Linux device model
458  * @cdev: character device object to create character device
459  * @ubi_num: UBI device number
460  * @ubi_name: UBI device name
461  * @vol_count: number of volumes in this UBI device
462  * @volumes: volumes of this UBI device
463  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
464  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
465  *                @vol->readers, @vol->writers, @vol->exclusive,
466  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
467  *                @vol->eba_tbl.
468  * @ref_count: count of references on the UBI device
469  * @image_seq: image sequence number recorded on EC headers
470  *
471  * @rsvd_pebs: count of reserved physical eraseblocks
472  * @avail_pebs: count of available physical eraseblocks
473  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
474  *                 handling
475  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
476  *
477  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
478  *                     of UBI initialization
479  * @vtbl_slots: how many slots are available in the volume table
480  * @vtbl_size: size of the volume table in bytes
481  * @vtbl: in-RAM volume table copy
482  * @device_mutex: protects on-flash volume table and serializes volume
483  *                creation, deletion, update, re-size, re-name and set
484  *                property
485  *
486  * @max_ec: current highest erase counter value
487  * @mean_ec: current mean erase counter value
488  *
489  * @global_sqnum: global sequence number
490  * @ltree_lock: protects the lock tree and @global_sqnum
491  * @ltree: the lock tree
492  * @alc_mutex: serializes "atomic LEB change" operations
493  *
494  * @fm_disabled: non-zero if fastmap is disabled (default)
495  * @fm: in-memory data structure of the currently used fastmap
496  * @fm_pool: in-memory data structure of the fastmap pool
497  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
498  *		sub-system
499  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
500  * that critical sections cannot be interrupted by ubi_update_fastmap()
501  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
502  * @fm_size: fastmap size in bytes
503  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
504  * @fm_work: fastmap work queue
505  * @fm_work_scheduled: non-zero if fastmap work was scheduled
506  * @fast_attach: non-zero if UBI was attached by fastmap
507  *
508  * @used: RB-tree of used physical eraseblocks
509  * @erroneous: RB-tree of erroneous used physical eraseblocks
510  * @free: RB-tree of free physical eraseblocks
511  * @free_count: Contains the number of elements in @free
512  * @scrub: RB-tree of physical eraseblocks which need scrubbing
513  * @pq: protection queue (contain physical eraseblocks which are temporarily
514  *      protected from the wear-leveling worker)
515  * @pq_head: protection queue head
516  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
517  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
518  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
519  *	     and @fm_wl_pool fields
520  * @move_mutex: serializes eraseblock moves
521  * @work_sem: used to wait for all the scheduled works to finish and prevent
522  * new works from being submitted
523  * @wl_scheduled: non-zero if the wear-leveling was scheduled
524  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
525  *             physical eraseblock
526  * @move_from: physical eraseblock from where the data is being moved
527  * @move_to: physical eraseblock where the data is being moved to
528  * @move_to_put: if the "to" PEB was put
529  * @works: list of pending works
530  * @works_count: count of pending works
531  * @bgt_thread: background thread description object
532  * @thread_enabled: if the background thread is enabled
533  * @bgt_name: background thread name
534  *
535  * @flash_size: underlying MTD device size (in bytes)
536  * @peb_count: count of physical eraseblocks on the MTD device
537  * @peb_size: physical eraseblock size
538  * @bad_peb_limit: top limit of expected bad physical eraseblocks
539  * @bad_peb_count: count of bad physical eraseblocks
540  * @good_peb_count: count of good physical eraseblocks
541  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
542  *                  used by UBI)
543  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
544  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
545  * @min_io_size: minimal input/output unit size of the underlying MTD device
546  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
547  * @ro_mode: if the UBI device is in read-only mode
548  * @leb_size: logical eraseblock size
549  * @leb_start: starting offset of logical eraseblocks within physical
550  *             eraseblocks
551  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
552  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
553  * @vid_hdr_offset: starting offset of the volume identifier header (might be
554  *                  unaligned)
555  * @vid_hdr_aloffset: starting offset of the VID header aligned to
556  *                    @hdrs_min_io_size
557  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
558  * @bad_allowed: whether the MTD device admits bad physical eraseblocks or not
559  * @nor_flash: non-zero if working on top of NOR flash
560  * @max_write_size: maximum amount of bytes the underlying flash can write at a
561  *                  time (MTD write buffer size)
562  * @mtd: MTD device descriptor
563  *
564  * @peb_buf: a buffer of PEB size used for different purposes
565  * @buf_mutex: protects @peb_buf
566  * @ckvol_mutex: serializes static volume checking when opening
567  *
568  * @dbg: debugging information for this UBI device
569  */
570 struct ubi_device {
571 	struct cdev cdev;
572 	struct device dev;
573 	int ubi_num;
574 	char ubi_name[sizeof(UBI_NAME_STR)+5];
575 	int vol_count;
576 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
577 	spinlock_t volumes_lock;
578 	int ref_count;
579 	int image_seq;
580 
581 	int rsvd_pebs;
582 	int avail_pebs;
583 	int beb_rsvd_pebs;
584 	int beb_rsvd_level;
585 	int bad_peb_limit;
586 
587 	int autoresize_vol_id;
588 	int vtbl_slots;
589 	int vtbl_size;
590 	struct ubi_vtbl_record *vtbl;
591 	struct mutex device_mutex;
592 
593 	int max_ec;
594 	/* Note, mean_ec is not updated run-time - should be fixed */
595 	int mean_ec;
596 
597 	/* EBA sub-system's stuff */
598 	unsigned long long global_sqnum;
599 	spinlock_t ltree_lock;
600 	struct rb_root ltree;
601 	struct mutex alc_mutex;
602 
603 	/* Fastmap stuff */
604 	int fm_disabled;
605 	struct ubi_fastmap_layout *fm;
606 	struct ubi_fm_pool fm_pool;
607 	struct ubi_fm_pool fm_wl_pool;
608 	struct rw_semaphore fm_eba_sem;
609 	struct rw_semaphore fm_protect;
610 	void *fm_buf;
611 	size_t fm_size;
612 	struct work_struct fm_work;
613 	int fm_work_scheduled;
614 	int fast_attach;
615 
616 	/* Wear-leveling sub-system's stuff */
617 	struct rb_root used;
618 	struct rb_root erroneous;
619 	struct rb_root free;
620 	int free_count;
621 	struct rb_root scrub;
622 	struct list_head pq[UBI_PROT_QUEUE_LEN];
623 	int pq_head;
624 	spinlock_t wl_lock;
625 	struct mutex move_mutex;
626 	struct rw_semaphore work_sem;
627 	int wl_scheduled;
628 	struct ubi_wl_entry **lookuptbl;
629 	struct ubi_wl_entry *move_from;
630 	struct ubi_wl_entry *move_to;
631 	int move_to_put;
632 	struct list_head works;
633 	int works_count;
634 	struct task_struct *bgt_thread;
635 	int thread_enabled;
636 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
637 
638 	/* I/O sub-system's stuff */
639 	long long flash_size;
640 	int peb_count;
641 	int peb_size;
642 	int bad_peb_count;
643 	int good_peb_count;
644 	int corr_peb_count;
645 	int erroneous_peb_count;
646 	int max_erroneous;
647 	int min_io_size;
648 	int hdrs_min_io_size;
649 	int ro_mode;
650 	int leb_size;
651 	int leb_start;
652 	int ec_hdr_alsize;
653 	int vid_hdr_alsize;
654 	int vid_hdr_offset;
655 	int vid_hdr_aloffset;
656 	int vid_hdr_shift;
657 	unsigned int bad_allowed:1;
658 	unsigned int nor_flash:1;
659 	int max_write_size;
660 	struct mtd_info *mtd;
661 
662 	void *peb_buf;
663 	struct mutex buf_mutex;
664 	struct mutex ckvol_mutex;
665 
666 	struct ubi_debug_info dbg;
667 };
668 
669 /**
670  * struct ubi_ainf_peb - attach information about a physical eraseblock.
671  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
672  * @pnum: physical eraseblock number
673  * @vol_id: ID of the volume this LEB belongs to
674  * @lnum: logical eraseblock number
675  * @scrub: if this physical eraseblock needs scrubbing
676  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
677  * @sqnum: sequence number
678  * @u: unions RB-tree or @list links
679  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
680  * @u.list: link in one of the eraseblock lists
681  *
682  * One object of this type is allocated for each physical eraseblock when
683  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
684  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
685  */
686 struct ubi_ainf_peb {
687 	int ec;
688 	int pnum;
689 	int vol_id;
690 	int lnum;
691 	unsigned int scrub:1;
692 	unsigned int copy_flag:1;
693 	unsigned long long sqnum;
694 	union {
695 		struct rb_node rb;
696 		struct list_head list;
697 	} u;
698 };
699 
700 /**
701  * struct ubi_ainf_volume - attaching information about a volume.
702  * @vol_id: volume ID
703  * @highest_lnum: highest logical eraseblock number in this volume
704  * @leb_count: number of logical eraseblocks in this volume
705  * @vol_type: volume type
706  * @used_ebs: number of used logical eraseblocks in this volume (only for
707  *            static volumes)
708  * @last_data_size: amount of data in the last logical eraseblock of this
709  *                  volume (always equivalent to the usable logical eraseblock
710  *                  size in case of dynamic volumes)
711  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
712  *            are not used (due to volume alignment)
713  * @compat: compatibility flags of this volume
714  * @rb: link in the volume RB-tree
715  * @root: root of the RB-tree containing all the eraseblock belonging to this
716  *        volume (&struct ubi_ainf_peb objects)
717  *
718  * One object of this type is allocated for each volume when attaching an MTD
719  * device.
720  */
721 struct ubi_ainf_volume {
722 	int vol_id;
723 	int highest_lnum;
724 	int leb_count;
725 	int vol_type;
726 	int used_ebs;
727 	int last_data_size;
728 	int data_pad;
729 	int compat;
730 	struct rb_node rb;
731 	struct rb_root root;
732 };
733 
734 /**
735  * struct ubi_attach_info - MTD device attaching information.
736  * @volumes: root of the volume RB-tree
737  * @corr: list of corrupted physical eraseblocks
738  * @free: list of free physical eraseblocks
739  * @erase: list of physical eraseblocks which have to be erased
740  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
741  *         those belonging to "preserve"-compatible internal volumes)
742  * @fastmap: list of physical eraseblocks which relate to fastmap (e.g.,
743  *           eraseblocks of the current and not yet erased old fastmap blocks)
744  * @corr_peb_count: count of PEBs in the @corr list
745  * @empty_peb_count: count of PEBs which are presumably empty (contain only
746  *                   0xFF bytes)
747  * @alien_peb_count: count of PEBs in the @alien list
748  * @bad_peb_count: count of bad physical eraseblocks
749  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
750  *                       as bad yet, but which look like bad
751  * @vols_found: number of volumes found
752  * @highest_vol_id: highest volume ID
753  * @is_empty: flag indicating whether the MTD device is empty or not
754  * @force_full_scan: flag indicating whether we need to do a full scan and drop
755 		     all existing Fastmap data structures
756  * @min_ec: lowest erase counter value
757  * @max_ec: highest erase counter value
758  * @max_sqnum: highest sequence number value
759  * @mean_ec: mean erase counter value
760  * @ec_sum: a temporary variable used when calculating @mean_ec
761  * @ec_count: a temporary variable used when calculating @mean_ec
762  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
763  * @ech: temporary EC header. Only available during scan
764  * @vidh: temporary VID buffer. Only available during scan
765  *
766  * This data structure contains the result of attaching an MTD device and may
767  * be used by other UBI sub-systems to build final UBI data structures, further
768  * error-recovery and so on.
769  */
770 struct ubi_attach_info {
771 	struct rb_root volumes;
772 	struct list_head corr;
773 	struct list_head free;
774 	struct list_head erase;
775 	struct list_head alien;
776 	struct list_head fastmap;
777 	int corr_peb_count;
778 	int empty_peb_count;
779 	int alien_peb_count;
780 	int bad_peb_count;
781 	int maybe_bad_peb_count;
782 	int vols_found;
783 	int highest_vol_id;
784 	int is_empty;
785 	int force_full_scan;
786 	int min_ec;
787 	int max_ec;
788 	unsigned long long max_sqnum;
789 	int mean_ec;
790 	uint64_t ec_sum;
791 	int ec_count;
792 	struct kmem_cache *aeb_slab_cache;
793 	struct ubi_ec_hdr *ech;
794 	struct ubi_vid_io_buf *vidb;
795 };
796 
797 /**
798  * struct ubi_work - UBI work description data structure.
799  * @list: a link in the list of pending works
800  * @func: worker function
801  * @e: physical eraseblock to erase
802  * @vol_id: the volume ID on which this erasure is being performed
803  * @lnum: the logical eraseblock number
804  * @torture: if the physical eraseblock has to be tortured
805  * @anchor: produce a anchor PEB to by used by fastmap
806  *
807  * The @func pointer points to the worker function. If the @shutdown argument is
808  * not zero, the worker has to free the resources and exit immediately as the
809  * WL sub-system is shutting down.
810  * The worker has to return zero in case of success and a negative error code in
811  * case of failure.
812  */
813 struct ubi_work {
814 	struct list_head list;
815 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
816 	/* The below fields are only relevant to erasure works */
817 	struct ubi_wl_entry *e;
818 	int vol_id;
819 	int lnum;
820 	int torture;
821 	int anchor;
822 };
823 
824 #include "debug.h"
825 
826 extern struct kmem_cache *ubi_wl_entry_slab;
827 extern const struct file_operations ubi_ctrl_cdev_operations;
828 extern const struct file_operations ubi_cdev_operations;
829 extern const struct file_operations ubi_vol_cdev_operations;
830 extern struct class ubi_class;
831 extern struct mutex ubi_devices_mutex;
832 extern struct blocking_notifier_head ubi_notifiers;
833 
834 /* attach.c */
835 struct ubi_ainf_peb *ubi_alloc_aeb(struct ubi_attach_info *ai, int pnum,
836 				   int ec);
837 void ubi_free_aeb(struct ubi_attach_info *ai, struct ubi_ainf_peb *aeb);
838 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
839 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
840 struct ubi_ainf_volume *ubi_add_av(struct ubi_attach_info *ai, int vol_id);
841 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
842 				    int vol_id);
843 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
844 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
845 				       struct ubi_attach_info *ai);
846 int ubi_attach(struct ubi_device *ubi, int force_scan);
847 void ubi_destroy_ai(struct ubi_attach_info *ai);
848 
849 /* vtbl.c */
850 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
851 			   struct ubi_vtbl_record *vtbl_rec);
852 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
853 			    struct list_head *rename_list);
854 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
855 
856 /* vmt.c */
857 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
858 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
859 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
860 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
861 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
862 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
863 
864 /* upd.c */
865 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
866 		     long long bytes);
867 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
868 			 const void __user *buf, int count);
869 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
870 			 const struct ubi_leb_change_req *req);
871 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
872 			     const void __user *buf, int count);
873 
874 /* misc.c */
875 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
876 		      int length);
877 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
878 void ubi_update_reserved(struct ubi_device *ubi);
879 void ubi_calculate_reserved(struct ubi_device *ubi);
880 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
881 
882 static inline bool ubi_leb_valid(struct ubi_volume *vol, int lnum)
883 {
884 	return lnum >= 0 && lnum < vol->reserved_pebs;
885 }
886 
887 /* eba.c */
888 struct ubi_eba_table *ubi_eba_create_table(struct ubi_volume *vol,
889 					   int nentries);
890 void ubi_eba_destroy_table(struct ubi_eba_table *tbl);
891 void ubi_eba_copy_table(struct ubi_volume *vol, struct ubi_eba_table *dst,
892 			int nentries);
893 void ubi_eba_replace_table(struct ubi_volume *vol, struct ubi_eba_table *tbl);
894 void ubi_eba_get_ldesc(struct ubi_volume *vol, int lnum,
895 		       struct ubi_eba_leb_desc *ldesc);
896 bool ubi_eba_is_mapped(struct ubi_volume *vol, int lnum);
897 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
898 		      int lnum);
899 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
900 		     void *buf, int offset, int len, int check);
901 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
902 			struct ubi_sgl *sgl, int lnum, int offset, int len,
903 			int check);
904 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
905 		      const void *buf, int offset, int len);
906 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
907 			 int lnum, const void *buf, int len, int used_ebs);
908 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
909 			      int lnum, const void *buf, int len);
910 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
911 		     struct ubi_vid_io_buf *vidb);
912 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
913 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
914 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
915 		   struct ubi_attach_info *ai_scan);
916 
917 /* wl.c */
918 int ubi_wl_get_peb(struct ubi_device *ubi);
919 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
920 		   int pnum, int torture);
921 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
922 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
923 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
924 void ubi_wl_close(struct ubi_device *ubi);
925 int ubi_thread(void *u);
926 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
927 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
928 		      int lnum, int torture);
929 int ubi_is_erase_work(struct ubi_work *wrk);
930 void ubi_refill_pools(struct ubi_device *ubi);
931 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
932 
933 /* io.c */
934 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
935 		int len);
936 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
937 		 int len);
938 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
939 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
940 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
941 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
942 		       struct ubi_ec_hdr *ec_hdr, int verbose);
943 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
944 			struct ubi_ec_hdr *ec_hdr);
945 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
946 			struct ubi_vid_io_buf *vidb, int verbose);
947 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
948 			 struct ubi_vid_io_buf *vidb);
949 
950 /* build.c */
951 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
952 		       int vid_hdr_offset, int max_beb_per1024);
953 int ubi_detach_mtd_dev(int ubi_num, int anyway);
954 struct ubi_device *ubi_get_device(int ubi_num);
955 void ubi_put_device(struct ubi_device *ubi);
956 struct ubi_device *ubi_get_by_major(int major);
957 int ubi_major2num(int major);
958 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
959 		      int ntype);
960 int ubi_notify_all(struct ubi_device *ubi, int ntype,
961 		   struct notifier_block *nb);
962 int ubi_enumerate_volumes(struct notifier_block *nb);
963 void ubi_free_internal_volumes(struct ubi_device *ubi);
964 
965 /* kapi.c */
966 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
967 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
968 			    struct ubi_volume_info *vi);
969 /* scan.c */
970 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
971 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
972 
973 /* fastmap.c */
974 #ifdef CONFIG_MTD_UBI_FASTMAP
975 size_t ubi_calc_fm_size(struct ubi_device *ubi);
976 int ubi_update_fastmap(struct ubi_device *ubi);
977 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
978 		     struct ubi_attach_info *scan_ai);
979 int ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count);
980 void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol);
981 #else
982 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
983 int static inline ubi_fastmap_init_checkmap(struct ubi_volume *vol, int leb_count) { return 0; }
984 static inline void ubi_fastmap_destroy_checkmap(struct ubi_volume *vol) {}
985 #endif
986 
987 /* block.c */
988 #ifdef CONFIG_MTD_UBI_BLOCK
989 int ubiblock_init(void);
990 void ubiblock_exit(void);
991 int ubiblock_create(struct ubi_volume_info *vi);
992 int ubiblock_remove(struct ubi_volume_info *vi);
993 #else
994 static inline int ubiblock_init(void) { return 0; }
995 static inline void ubiblock_exit(void) {}
996 static inline int ubiblock_create(struct ubi_volume_info *vi)
997 {
998 	return -ENOSYS;
999 }
1000 static inline int ubiblock_remove(struct ubi_volume_info *vi)
1001 {
1002 	return -ENOSYS;
1003 }
1004 #endif
1005 
1006 /*
1007  * ubi_for_each_free_peb - walk the UBI free RB tree.
1008  * @ubi: UBI device description object
1009  * @e: a pointer to a ubi_wl_entry to use as cursor
1010  * @pos: a pointer to RB-tree entry type to use as a loop counter
1011  */
1012 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
1013 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
1014 
1015 /*
1016  * ubi_for_each_used_peb - walk the UBI used RB tree.
1017  * @ubi: UBI device description object
1018  * @e: a pointer to a ubi_wl_entry to use as cursor
1019  * @pos: a pointer to RB-tree entry type to use as a loop counter
1020  */
1021 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
1022 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
1023 
1024 /*
1025  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
1026  * @ubi: UBI device description object
1027  * @e: a pointer to a ubi_wl_entry to use as cursor
1028  * @pos: a pointer to RB-tree entry type to use as a loop counter
1029  */
1030 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
1031 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
1032 
1033 /*
1034  * ubi_for_each_protected_peb - walk the UBI protection queue.
1035  * @ubi: UBI device description object
1036  * @i: a integer used as counter
1037  * @e: a pointer to a ubi_wl_entry to use as cursor
1038  */
1039 #define ubi_for_each_protected_peb(ubi, i, e)	\
1040 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
1041 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
1042 
1043 /*
1044  * ubi_rb_for_each_entry - walk an RB-tree.
1045  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
1046  * @pos: a pointer to RB-tree entry type to use as a loop counter
1047  * @root: RB-tree's root
1048  * @member: the name of the 'struct rb_node' within the RB-tree entry
1049  */
1050 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
1051 	for (rb = rb_first(root),                                            \
1052 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
1053 	     rb;                                                             \
1054 	     rb = rb_next(rb),                                               \
1055 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
1056 
1057 /*
1058  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
1059  *
1060  * @av: volume attaching information
1061  * @aeb: attaching eraseblock information
1062  * @list: the list to move to
1063  */
1064 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
1065 					 struct ubi_ainf_peb *aeb,
1066 					 struct list_head *list)
1067 {
1068 		rb_erase(&aeb->u.rb, &av->root);
1069 		list_add_tail(&aeb->u.list, list);
1070 }
1071 
1072 /**
1073  * ubi_init_vid_buf - Initialize a VID buffer
1074  * @ubi: the UBI device
1075  * @vidb: the VID buffer to initialize
1076  * @buf: the underlying buffer
1077  */
1078 static inline void ubi_init_vid_buf(const struct ubi_device *ubi,
1079 				    struct ubi_vid_io_buf *vidb,
1080 				    void *buf)
1081 {
1082 	if (buf)
1083 		memset(buf, 0, ubi->vid_hdr_alsize);
1084 
1085 	vidb->buffer = buf;
1086 	vidb->hdr = buf + ubi->vid_hdr_shift;
1087 }
1088 
1089 /**
1090  * ubi_init_vid_buf - Allocate a VID buffer
1091  * @ubi: the UBI device
1092  * @gfp_flags: GFP flags to use for the allocation
1093  */
1094 static inline struct ubi_vid_io_buf *
1095 ubi_alloc_vid_buf(const struct ubi_device *ubi, gfp_t gfp_flags)
1096 {
1097 	struct ubi_vid_io_buf *vidb;
1098 	void *buf;
1099 
1100 	vidb = kzalloc(sizeof(*vidb), gfp_flags);
1101 	if (!vidb)
1102 		return NULL;
1103 
1104 	buf = kmalloc(ubi->vid_hdr_alsize, gfp_flags);
1105 	if (!buf) {
1106 		kfree(vidb);
1107 		return NULL;
1108 	}
1109 
1110 	ubi_init_vid_buf(ubi, vidb, buf);
1111 
1112 	return vidb;
1113 }
1114 
1115 /**
1116  * ubi_free_vid_buf - Free a VID buffer
1117  * @vidb: the VID buffer to free
1118  */
1119 static inline void ubi_free_vid_buf(struct ubi_vid_io_buf *vidb)
1120 {
1121 	if (!vidb)
1122 		return;
1123 
1124 	kfree(vidb->buffer);
1125 	kfree(vidb);
1126 }
1127 
1128 /**
1129  * ubi_get_vid_hdr - Get the VID header attached to a VID buffer
1130  * @vidb: VID buffer
1131  */
1132 static inline struct ubi_vid_hdr *ubi_get_vid_hdr(struct ubi_vid_io_buf *vidb)
1133 {
1134 	return vidb->hdr;
1135 }
1136 
1137 /*
1138  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1139  * the beginning of the logical eraseblock, not to the beginning of the
1140  * physical eraseblock.
1141  */
1142 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1143 				   int pnum, int offset, int len)
1144 {
1145 	ubi_assert(offset >= 0);
1146 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1147 }
1148 
1149 /*
1150  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1151  * the beginning of the logical eraseblock, not to the beginning of the
1152  * physical eraseblock.
1153  */
1154 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1155 				    int pnum, int offset, int len)
1156 {
1157 	ubi_assert(offset >= 0);
1158 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1159 }
1160 
1161 /**
1162  * ubi_ro_mode - switch to read-only mode.
1163  * @ubi: UBI device description object
1164  */
1165 static inline void ubi_ro_mode(struct ubi_device *ubi)
1166 {
1167 	if (!ubi->ro_mode) {
1168 		ubi->ro_mode = 1;
1169 		ubi_warn(ubi, "switch to read-only mode");
1170 		dump_stack();
1171 	}
1172 }
1173 
1174 /**
1175  * vol_id2idx - get table index by volume ID.
1176  * @ubi: UBI device description object
1177  * @vol_id: volume ID
1178  */
1179 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1180 {
1181 	if (vol_id >= UBI_INTERNAL_VOL_START)
1182 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1183 	else
1184 		return vol_id;
1185 }
1186 
1187 /**
1188  * idx2vol_id - get volume ID by table index.
1189  * @ubi: UBI device description object
1190  * @idx: table index
1191  */
1192 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1193 {
1194 	if (idx >= ubi->vtbl_slots)
1195 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1196 	else
1197 		return idx;
1198 }
1199 
1200 /**
1201  * ubi_is_fm_vol - check whether a volume ID is a Fastmap volume.
1202  * @vol_id: volume ID
1203  */
1204 static inline bool ubi_is_fm_vol(int vol_id)
1205 {
1206 	switch (vol_id) {
1207 		case UBI_FM_SB_VOLUME_ID:
1208 		case UBI_FM_DATA_VOLUME_ID:
1209 		return true;
1210 	}
1211 
1212 	return false;
1213 }
1214 
1215 /**
1216  * ubi_find_fm_block - check whether a PEB is part of the current Fastmap.
1217  * @ubi: UBI device description object
1218  * @pnum: physical eraseblock to look for
1219  *
1220  * This function returns a wear leveling object if @pnum relates to the current
1221  * fastmap, @NULL otherwise.
1222  */
1223 static inline struct ubi_wl_entry *ubi_find_fm_block(const struct ubi_device *ubi,
1224 						     int pnum)
1225 {
1226 	int i;
1227 
1228 	if (ubi->fm) {
1229 		for (i = 0; i < ubi->fm->used_blocks; i++) {
1230 			if (ubi->fm->e[i]->pnum == pnum)
1231 				return ubi->fm->e[i];
1232 		}
1233 	}
1234 
1235 	return NULL;
1236 }
1237 
1238 #endif /* !__UBI_UBI_H__ */
1239