xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 827634ad)
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 /* Normal UBI messages */
53 #define ubi_msg(ubi, fmt, ...) pr_notice(UBI_NAME_STR "%d: " fmt "\n", \
54 					 ubi->ubi_num, ##__VA_ARGS__)
55 /* UBI warning messages */
56 #define ubi_warn(ubi, fmt, ...) pr_warn(UBI_NAME_STR "%d warning: %s: " fmt "\n", \
57 					ubi->ubi_num, __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(ubi, fmt, ...) pr_err(UBI_NAME_STR "%d error: %s: " fmt "\n", \
60 				      ubi->ubi_num, __func__, ##__VA_ARGS__)
61 
62 /* Background thread name pattern */
63 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
64 
65 /*
66  * This marker in the EBA table means that the LEB is um-mapped.
67  * NOTE! It has to have the same value as %UBI_ALL.
68  */
69 #define UBI_LEB_UNMAPPED -1
70 
71 /*
72  * In case of errors, UBI tries to repeat the operation several times before
73  * returning error. The below constant defines how many times UBI re-tries.
74  */
75 #define UBI_IO_RETRIES 3
76 
77 /*
78  * Length of the protection queue. The length is effectively equivalent to the
79  * number of (global) erase cycles PEBs are protected from the wear-leveling
80  * worker.
81  */
82 #define UBI_PROT_QUEUE_LEN 10
83 
84 /* The volume ID/LEB number/erase counter is unknown */
85 #define UBI_UNKNOWN -1
86 
87 /*
88  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
89  * + 2 for the number plus 1 for the trailing zero byte.
90  */
91 #define UBI_DFS_DIR_NAME "ubi%d"
92 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
93 
94 /*
95  * Error codes returned by the I/O sub-system.
96  *
97  * UBI_IO_FF: the read region of flash contains only 0xFFs
98  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
99  *                     integrity error reported by the MTD driver
100  *                     (uncorrectable ECC error in case of NAND)
101  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
102  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
103  *                         data integrity error reported by the MTD driver
104  *                         (uncorrectable ECC error in case of NAND)
105  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
106  *
107  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
108  * be or'ed with other error code. But this is a big change because there are
109  * may callers, so it does not worth the risk of introducing a bug
110  */
111 enum {
112 	UBI_IO_FF = 1,
113 	UBI_IO_FF_BITFLIPS,
114 	UBI_IO_BAD_HDR,
115 	UBI_IO_BAD_HDR_EBADMSG,
116 	UBI_IO_BITFLIPS,
117 };
118 
119 /*
120  * Return codes of the 'ubi_eba_copy_leb()' function.
121  *
122  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
123  *                   PEB was put meanwhile, or there is I/O on the source PEB
124  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
125  *                     PEB
126  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
127  *                     PEB
128  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
129  *                     PEB
130  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
131  *                       target PEB
132  * MOVE_RETRY: retry scrubbing the PEB
133  */
134 enum {
135 	MOVE_CANCEL_RACE = 1,
136 	MOVE_SOURCE_RD_ERR,
137 	MOVE_TARGET_RD_ERR,
138 	MOVE_TARGET_WR_ERR,
139 	MOVE_TARGET_BITFLIPS,
140 	MOVE_RETRY,
141 };
142 
143 /*
144  * Return codes of the fastmap sub-system
145  *
146  * UBI_NO_FASTMAP: No fastmap super block was found
147  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
148  */
149 enum {
150 	UBI_NO_FASTMAP = 1,
151 	UBI_BAD_FASTMAP,
152 };
153 
154 /*
155  * Flags for emulate_power_cut in ubi_debug_info
156  *
157  * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
158  * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
159  */
160 enum {
161 	POWER_CUT_EC_WRITE = 0x01,
162 	POWER_CUT_VID_WRITE = 0x02,
163 };
164 
165 /**
166  * struct ubi_wl_entry - wear-leveling entry.
167  * @u.rb: link in the corresponding (free/used) RB-tree
168  * @u.list: link in the protection queue
169  * @ec: erase counter
170  * @pnum: physical eraseblock number
171  *
172  * This data structure is used in the WL sub-system. Each physical eraseblock
173  * has a corresponding &struct wl_entry object which may be kept in different
174  * RB-trees. See WL sub-system for details.
175  */
176 struct ubi_wl_entry {
177 	union {
178 		struct rb_node rb;
179 		struct list_head list;
180 	} u;
181 	int ec;
182 	int pnum;
183 };
184 
185 /**
186  * struct ubi_ltree_entry - an entry in the lock tree.
187  * @rb: links RB-tree nodes
188  * @vol_id: volume ID of the locked logical eraseblock
189  * @lnum: locked logical eraseblock number
190  * @users: how many tasks are using this logical eraseblock or wait for it
191  * @mutex: read/write mutex to implement read/write access serialization to
192  *         the (@vol_id, @lnum) logical eraseblock
193  *
194  * This data structure is used in the EBA sub-system to implement per-LEB
195  * locking. When a logical eraseblock is being locked - corresponding
196  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
197  * See EBA sub-system for details.
198  */
199 struct ubi_ltree_entry {
200 	struct rb_node rb;
201 	int vol_id;
202 	int lnum;
203 	int users;
204 	struct rw_semaphore mutex;
205 };
206 
207 /**
208  * struct ubi_rename_entry - volume re-name description data structure.
209  * @new_name_len: new volume name length
210  * @new_name: new volume name
211  * @remove: if not zero, this volume should be removed, not re-named
212  * @desc: descriptor of the volume
213  * @list: links re-name entries into a list
214  *
215  * This data structure is utilized in the multiple volume re-name code. Namely,
216  * UBI first creates a list of &struct ubi_rename_entry objects from the
217  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
218  * the job.
219  */
220 struct ubi_rename_entry {
221 	int new_name_len;
222 	char new_name[UBI_VOL_NAME_MAX + 1];
223 	int remove;
224 	struct ubi_volume_desc *desc;
225 	struct list_head list;
226 };
227 
228 struct ubi_volume_desc;
229 
230 /**
231  * struct ubi_fastmap_layout - in-memory fastmap data structure.
232  * @e: PEBs used by the current fastmap
233  * @to_be_tortured: if non-zero tortured this PEB
234  * @used_blocks: number of used PEBs
235  * @max_pool_size: maximal size of the user pool
236  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
237  */
238 struct ubi_fastmap_layout {
239 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
240 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
241 	int used_blocks;
242 	int max_pool_size;
243 	int max_wl_pool_size;
244 };
245 
246 /**
247  * struct ubi_fm_pool - in-memory fastmap pool
248  * @pebs: PEBs in this pool
249  * @used: number of used PEBs
250  * @size: total number of PEBs in this pool
251  * @max_size: maximal size of the pool
252  *
253  * A pool gets filled with up to max_size.
254  * If all PEBs within the pool are used a new fastmap will be written
255  * to the flash and the pool gets refilled with empty PEBs.
256  *
257  */
258 struct ubi_fm_pool {
259 	int pebs[UBI_FM_MAX_POOL_SIZE];
260 	int used;
261 	int size;
262 	int max_size;
263 };
264 
265 /**
266  * struct ubi_volume - UBI volume description data structure.
267  * @dev: device object to make use of the the Linux device model
268  * @cdev: character device object to create character device
269  * @ubi: reference to the UBI device description object
270  * @vol_id: volume ID
271  * @ref_count: volume reference count
272  * @readers: number of users holding this volume in read-only mode
273  * @writers: number of users holding this volume in read-write mode
274  * @exclusive: whether somebody holds this volume in exclusive mode
275  * @metaonly: whether somebody is altering only meta data of this volume
276  *
277  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
278  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
279  * @usable_leb_size: logical eraseblock size without padding
280  * @used_ebs: how many logical eraseblocks in this volume contain data
281  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
282  * @used_bytes: how many bytes of data this volume contains
283  * @alignment: volume alignment
284  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
285  *            satisfy the requested alignment
286  * @name_len: volume name length
287  * @name: volume name
288  *
289  * @upd_ebs: how many eraseblocks are expected to be updated
290  * @ch_lnum: LEB number which is being changing by the atomic LEB change
291  *           operation
292  * @upd_bytes: how many bytes are expected to be received for volume update or
293  *             atomic LEB change
294  * @upd_received: how many bytes were already received for volume update or
295  *                atomic LEB change
296  * @upd_buf: update buffer which is used to collect update data or data for
297  *           atomic LEB change
298  *
299  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
300  * @checked: %1 if this static volume was checked
301  * @corrupted: %1 if the volume is corrupted (static volumes only)
302  * @upd_marker: %1 if the update marker is set for this volume
303  * @updating: %1 if the volume is being updated
304  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
305  * @direct_writes: %1 if direct writes are enabled for this volume
306  *
307  * The @corrupted field indicates that the volume's contents is corrupted.
308  * Since UBI protects only static volumes, this field is not relevant to
309  * dynamic volumes - it is user's responsibility to assure their data
310  * integrity.
311  *
312  * The @upd_marker flag indicates that this volume is either being updated at
313  * the moment or is damaged because of an unclean reboot.
314  */
315 struct ubi_volume {
316 	struct device dev;
317 	struct cdev cdev;
318 	struct ubi_device *ubi;
319 	int vol_id;
320 	int ref_count;
321 	int readers;
322 	int writers;
323 	int exclusive;
324 	int metaonly;
325 
326 	int reserved_pebs;
327 	int vol_type;
328 	int usable_leb_size;
329 	int used_ebs;
330 	int last_eb_bytes;
331 	long long used_bytes;
332 	int alignment;
333 	int data_pad;
334 	int name_len;
335 	char name[UBI_VOL_NAME_MAX + 1];
336 
337 	int upd_ebs;
338 	int ch_lnum;
339 	long long upd_bytes;
340 	long long upd_received;
341 	void *upd_buf;
342 
343 	int *eba_tbl;
344 	unsigned int checked:1;
345 	unsigned int corrupted:1;
346 	unsigned int upd_marker:1;
347 	unsigned int updating:1;
348 	unsigned int changing_leb:1;
349 	unsigned int direct_writes:1;
350 };
351 
352 /**
353  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
354  * @vol: reference to the corresponding volume description object
355  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
356  * or %UBI_METAONLY)
357  */
358 struct ubi_volume_desc {
359 	struct ubi_volume *vol;
360 	int mode;
361 };
362 
363 struct ubi_wl_entry;
364 
365 /**
366  * struct ubi_debug_info - debugging information for an UBI device.
367  *
368  * @chk_gen: if UBI general extra checks are enabled
369  * @chk_io: if UBI I/O extra checks are enabled
370  * @chk_fastmap: if UBI fastmap extra checks are enabled
371  * @disable_bgt: disable the background task for testing purposes
372  * @emulate_bitflips: emulate bit-flips for testing purposes
373  * @emulate_io_failures: emulate write/erase failures for testing purposes
374  * @emulate_power_cut: emulate power cut for testing purposes
375  * @power_cut_counter: count down for writes left until emulated power cut
376  * @power_cut_min: minimum number of writes before emulating a power cut
377  * @power_cut_max: maximum number of writes until emulating a power cut
378  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
379  * @dfs_dir: direntry object of the UBI device debugfs directory
380  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
381  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
382  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
383  * @dfs_disable_bgt: debugfs knob to disable the background task
384  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
385  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
386  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
387  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
388  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
389  */
390 struct ubi_debug_info {
391 	unsigned int chk_gen:1;
392 	unsigned int chk_io:1;
393 	unsigned int chk_fastmap:1;
394 	unsigned int disable_bgt:1;
395 	unsigned int emulate_bitflips:1;
396 	unsigned int emulate_io_failures:1;
397 	unsigned int emulate_power_cut:2;
398 	unsigned int power_cut_counter;
399 	unsigned int power_cut_min;
400 	unsigned int power_cut_max;
401 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
402 	struct dentry *dfs_dir;
403 	struct dentry *dfs_chk_gen;
404 	struct dentry *dfs_chk_io;
405 	struct dentry *dfs_chk_fastmap;
406 	struct dentry *dfs_disable_bgt;
407 	struct dentry *dfs_emulate_bitflips;
408 	struct dentry *dfs_emulate_io_failures;
409 	struct dentry *dfs_emulate_power_cut;
410 	struct dentry *dfs_power_cut_min;
411 	struct dentry *dfs_power_cut_max;
412 };
413 
414 /**
415  * struct ubi_device - UBI device description structure
416  * @dev: UBI device object to use the the Linux device model
417  * @cdev: character device object to create character device
418  * @ubi_num: UBI device number
419  * @ubi_name: UBI device name
420  * @vol_count: number of volumes in this UBI device
421  * @volumes: volumes of this UBI device
422  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
423  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
424  *                @vol->readers, @vol->writers, @vol->exclusive,
425  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
426  *                @vol->eba_tbl.
427  * @ref_count: count of references on the UBI device
428  * @image_seq: image sequence number recorded on EC headers
429  *
430  * @rsvd_pebs: count of reserved physical eraseblocks
431  * @avail_pebs: count of available physical eraseblocks
432  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
433  *                 handling
434  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
435  *
436  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
437  *                     of UBI initialization
438  * @vtbl_slots: how many slots are available in the volume table
439  * @vtbl_size: size of the volume table in bytes
440  * @vtbl: in-RAM volume table copy
441  * @device_mutex: protects on-flash volume table and serializes volume
442  *                creation, deletion, update, re-size, re-name and set
443  *                property
444  *
445  * @max_ec: current highest erase counter value
446  * @mean_ec: current mean erase counter value
447  *
448  * @global_sqnum: global sequence number
449  * @ltree_lock: protects the lock tree and @global_sqnum
450  * @ltree: the lock tree
451  * @alc_mutex: serializes "atomic LEB change" operations
452  *
453  * @fm_disabled: non-zero if fastmap is disabled (default)
454  * @fm: in-memory data structure of the currently used fastmap
455  * @fm_pool: in-memory data structure of the fastmap pool
456  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
457  *		sub-system
458  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
459  * that critical sections cannot be interrupted by ubi_update_fastmap()
460  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
461  * @fm_size: fastmap size in bytes
462  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
463  * @fm_work: fastmap work queue
464  * @fm_work_scheduled: non-zero if fastmap work was scheduled
465  *
466  * @used: RB-tree of used physical eraseblocks
467  * @erroneous: RB-tree of erroneous used physical eraseblocks
468  * @free: RB-tree of free physical eraseblocks
469  * @free_count: Contains the number of elements in @free
470  * @scrub: RB-tree of physical eraseblocks which need scrubbing
471  * @pq: protection queue (contain physical eraseblocks which are temporarily
472  *      protected from the wear-leveling worker)
473  * @pq_head: protection queue head
474  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
475  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
476  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
477  *	     and @fm_wl_pool fields
478  * @move_mutex: serializes eraseblock moves
479  * @work_sem: used to wait for all the scheduled works to finish and prevent
480  * new works from being submitted
481  * @wl_scheduled: non-zero if the wear-leveling was scheduled
482  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
483  *             physical eraseblock
484  * @move_from: physical eraseblock from where the data is being moved
485  * @move_to: physical eraseblock where the data is being moved to
486  * @move_to_put: if the "to" PEB was put
487  * @works: list of pending works
488  * @works_count: count of pending works
489  * @bgt_thread: background thread description object
490  * @thread_enabled: if the background thread is enabled
491  * @bgt_name: background thread name
492  *
493  * @flash_size: underlying MTD device size (in bytes)
494  * @peb_count: count of physical eraseblocks on the MTD device
495  * @peb_size: physical eraseblock size
496  * @bad_peb_limit: top limit of expected bad physical eraseblocks
497  * @bad_peb_count: count of bad physical eraseblocks
498  * @good_peb_count: count of good physical eraseblocks
499  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
500  *                  used by UBI)
501  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
502  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
503  * @min_io_size: minimal input/output unit size of the underlying MTD device
504  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
505  * @ro_mode: if the UBI device is in read-only mode
506  * @leb_size: logical eraseblock size
507  * @leb_start: starting offset of logical eraseblocks within physical
508  *             eraseblocks
509  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
510  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
511  * @vid_hdr_offset: starting offset of the volume identifier header (might be
512  *                  unaligned)
513  * @vid_hdr_aloffset: starting offset of the VID header aligned to
514  *                    @hdrs_min_io_size
515  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
516  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
517  *               not
518  * @nor_flash: non-zero if working on top of NOR flash
519  * @max_write_size: maximum amount of bytes the underlying flash can write at a
520  *                  time (MTD write buffer size)
521  * @mtd: MTD device descriptor
522  *
523  * @peb_buf: a buffer of PEB size used for different purposes
524  * @buf_mutex: protects @peb_buf
525  * @ckvol_mutex: serializes static volume checking when opening
526  *
527  * @dbg: debugging information for this UBI device
528  */
529 struct ubi_device {
530 	struct cdev cdev;
531 	struct device dev;
532 	int ubi_num;
533 	char ubi_name[sizeof(UBI_NAME_STR)+5];
534 	int vol_count;
535 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
536 	spinlock_t volumes_lock;
537 	int ref_count;
538 	int image_seq;
539 
540 	int rsvd_pebs;
541 	int avail_pebs;
542 	int beb_rsvd_pebs;
543 	int beb_rsvd_level;
544 	int bad_peb_limit;
545 
546 	int autoresize_vol_id;
547 	int vtbl_slots;
548 	int vtbl_size;
549 	struct ubi_vtbl_record *vtbl;
550 	struct mutex device_mutex;
551 
552 	int max_ec;
553 	/* Note, mean_ec is not updated run-time - should be fixed */
554 	int mean_ec;
555 
556 	/* EBA sub-system's stuff */
557 	unsigned long long global_sqnum;
558 	spinlock_t ltree_lock;
559 	struct rb_root ltree;
560 	struct mutex alc_mutex;
561 
562 	/* Fastmap stuff */
563 	int fm_disabled;
564 	struct ubi_fastmap_layout *fm;
565 	struct ubi_fm_pool fm_pool;
566 	struct ubi_fm_pool fm_wl_pool;
567 	struct rw_semaphore fm_eba_sem;
568 	struct rw_semaphore fm_protect;
569 	void *fm_buf;
570 	size_t fm_size;
571 	struct work_struct fm_work;
572 	int fm_work_scheduled;
573 
574 	/* Wear-leveling sub-system's stuff */
575 	struct rb_root used;
576 	struct rb_root erroneous;
577 	struct rb_root free;
578 	int free_count;
579 	struct rb_root scrub;
580 	struct list_head pq[UBI_PROT_QUEUE_LEN];
581 	int pq_head;
582 	spinlock_t wl_lock;
583 	struct mutex move_mutex;
584 	struct rw_semaphore work_sem;
585 	int wl_scheduled;
586 	struct ubi_wl_entry **lookuptbl;
587 	struct ubi_wl_entry *move_from;
588 	struct ubi_wl_entry *move_to;
589 	int move_to_put;
590 	struct list_head works;
591 	int works_count;
592 	struct task_struct *bgt_thread;
593 	int thread_enabled;
594 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
595 
596 	/* I/O sub-system's stuff */
597 	long long flash_size;
598 	int peb_count;
599 	int peb_size;
600 	int bad_peb_count;
601 	int good_peb_count;
602 	int corr_peb_count;
603 	int erroneous_peb_count;
604 	int max_erroneous;
605 	int min_io_size;
606 	int hdrs_min_io_size;
607 	int ro_mode;
608 	int leb_size;
609 	int leb_start;
610 	int ec_hdr_alsize;
611 	int vid_hdr_alsize;
612 	int vid_hdr_offset;
613 	int vid_hdr_aloffset;
614 	int vid_hdr_shift;
615 	unsigned int bad_allowed:1;
616 	unsigned int nor_flash:1;
617 	int max_write_size;
618 	struct mtd_info *mtd;
619 
620 	void *peb_buf;
621 	struct mutex buf_mutex;
622 	struct mutex ckvol_mutex;
623 
624 	struct ubi_debug_info dbg;
625 };
626 
627 /**
628  * struct ubi_ainf_peb - attach information about a physical eraseblock.
629  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
630  * @pnum: physical eraseblock number
631  * @vol_id: ID of the volume this LEB belongs to
632  * @lnum: logical eraseblock number
633  * @scrub: if this physical eraseblock needs scrubbing
634  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
635  * @sqnum: sequence number
636  * @u: unions RB-tree or @list links
637  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
638  * @u.list: link in one of the eraseblock lists
639  *
640  * One object of this type is allocated for each physical eraseblock when
641  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
642  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
643  */
644 struct ubi_ainf_peb {
645 	int ec;
646 	int pnum;
647 	int vol_id;
648 	int lnum;
649 	unsigned int scrub:1;
650 	unsigned int copy_flag:1;
651 	unsigned long long sqnum;
652 	union {
653 		struct rb_node rb;
654 		struct list_head list;
655 	} u;
656 };
657 
658 /**
659  * struct ubi_ainf_volume - attaching information about a volume.
660  * @vol_id: volume ID
661  * @highest_lnum: highest logical eraseblock number in this volume
662  * @leb_count: number of logical eraseblocks in this volume
663  * @vol_type: volume type
664  * @used_ebs: number of used logical eraseblocks in this volume (only for
665  *            static volumes)
666  * @last_data_size: amount of data in the last logical eraseblock of this
667  *                  volume (always equivalent to the usable logical eraseblock
668  *                  size in case of dynamic volumes)
669  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
670  *            are not used (due to volume alignment)
671  * @compat: compatibility flags of this volume
672  * @rb: link in the volume RB-tree
673  * @root: root of the RB-tree containing all the eraseblock belonging to this
674  *        volume (&struct ubi_ainf_peb objects)
675  *
676  * One object of this type is allocated for each volume when attaching an MTD
677  * device.
678  */
679 struct ubi_ainf_volume {
680 	int vol_id;
681 	int highest_lnum;
682 	int leb_count;
683 	int vol_type;
684 	int used_ebs;
685 	int last_data_size;
686 	int data_pad;
687 	int compat;
688 	struct rb_node rb;
689 	struct rb_root root;
690 };
691 
692 /**
693  * struct ubi_attach_info - MTD device attaching information.
694  * @volumes: root of the volume RB-tree
695  * @corr: list of corrupted physical eraseblocks
696  * @free: list of free physical eraseblocks
697  * @erase: list of physical eraseblocks which have to be erased
698  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
699  *         those belonging to "preserve"-compatible internal volumes)
700  * @corr_peb_count: count of PEBs in the @corr list
701  * @empty_peb_count: count of PEBs which are presumably empty (contain only
702  *                   0xFF bytes)
703  * @alien_peb_count: count of PEBs in the @alien list
704  * @bad_peb_count: count of bad physical eraseblocks
705  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
706  *                       as bad yet, but which look like bad
707  * @vols_found: number of volumes found
708  * @highest_vol_id: highest volume ID
709  * @is_empty: flag indicating whether the MTD device is empty or not
710  * @min_ec: lowest erase counter value
711  * @max_ec: highest erase counter value
712  * @max_sqnum: highest sequence number value
713  * @mean_ec: mean erase counter value
714  * @ec_sum: a temporary variable used when calculating @mean_ec
715  * @ec_count: a temporary variable used when calculating @mean_ec
716  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
717  *
718  * This data structure contains the result of attaching an MTD device and may
719  * be used by other UBI sub-systems to build final UBI data structures, further
720  * error-recovery and so on.
721  */
722 struct ubi_attach_info {
723 	struct rb_root volumes;
724 	struct list_head corr;
725 	struct list_head free;
726 	struct list_head erase;
727 	struct list_head alien;
728 	int corr_peb_count;
729 	int empty_peb_count;
730 	int alien_peb_count;
731 	int bad_peb_count;
732 	int maybe_bad_peb_count;
733 	int vols_found;
734 	int highest_vol_id;
735 	int is_empty;
736 	int min_ec;
737 	int max_ec;
738 	unsigned long long max_sqnum;
739 	int mean_ec;
740 	uint64_t ec_sum;
741 	int ec_count;
742 	struct kmem_cache *aeb_slab_cache;
743 };
744 
745 /**
746  * struct ubi_work - UBI work description data structure.
747  * @list: a link in the list of pending works
748  * @func: worker function
749  * @e: physical eraseblock to erase
750  * @vol_id: the volume ID on which this erasure is being performed
751  * @lnum: the logical eraseblock number
752  * @torture: if the physical eraseblock has to be tortured
753  * @anchor: produce a anchor PEB to by used by fastmap
754  *
755  * The @func pointer points to the worker function. If the @shutdown argument is
756  * not zero, the worker has to free the resources and exit immediately as the
757  * WL sub-system is shutting down.
758  * The worker has to return zero in case of success and a negative error code in
759  * case of failure.
760  */
761 struct ubi_work {
762 	struct list_head list;
763 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
764 	/* The below fields are only relevant to erasure works */
765 	struct ubi_wl_entry *e;
766 	int vol_id;
767 	int lnum;
768 	int torture;
769 	int anchor;
770 };
771 
772 #include "debug.h"
773 
774 extern struct kmem_cache *ubi_wl_entry_slab;
775 extern const struct file_operations ubi_ctrl_cdev_operations;
776 extern const struct file_operations ubi_cdev_operations;
777 extern const struct file_operations ubi_vol_cdev_operations;
778 extern struct class *ubi_class;
779 extern struct mutex ubi_devices_mutex;
780 extern struct blocking_notifier_head ubi_notifiers;
781 
782 /* attach.c */
783 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
784 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
785 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
786 				    int vol_id);
787 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
788 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
789 				       struct ubi_attach_info *ai);
790 int ubi_attach(struct ubi_device *ubi, int force_scan);
791 void ubi_destroy_ai(struct ubi_attach_info *ai);
792 
793 /* vtbl.c */
794 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
795 			   struct ubi_vtbl_record *vtbl_rec);
796 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
797 			    struct list_head *rename_list);
798 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
799 
800 /* vmt.c */
801 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
802 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
803 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
804 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
805 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
806 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
807 
808 /* upd.c */
809 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
810 		     long long bytes);
811 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
812 			 const void __user *buf, int count);
813 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
814 			 const struct ubi_leb_change_req *req);
815 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
816 			     const void __user *buf, int count);
817 
818 /* misc.c */
819 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
820 		      int length);
821 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
822 void ubi_update_reserved(struct ubi_device *ubi);
823 void ubi_calculate_reserved(struct ubi_device *ubi);
824 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
825 
826 /* eba.c */
827 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
828 		      int lnum);
829 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
830 		     void *buf, int offset, int len, int check);
831 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
832 			struct ubi_sgl *sgl, int lnum, int offset, int len,
833 			int check);
834 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
835 		      const void *buf, int offset, int len);
836 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
837 			 int lnum, const void *buf, int len, int used_ebs);
838 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
839 			      int lnum, const void *buf, int len);
840 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
841 		     struct ubi_vid_hdr *vid_hdr);
842 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
843 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
844 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
845 		   struct ubi_attach_info *ai_scan);
846 
847 /* wl.c */
848 int ubi_wl_get_peb(struct ubi_device *ubi);
849 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
850 		   int pnum, int torture);
851 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
852 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
853 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
854 void ubi_wl_close(struct ubi_device *ubi);
855 int ubi_thread(void *u);
856 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
857 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
858 		      int lnum, int torture);
859 int ubi_is_erase_work(struct ubi_work *wrk);
860 void ubi_refill_pools(struct ubi_device *ubi);
861 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
862 
863 /* io.c */
864 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
865 		int len);
866 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
867 		 int len);
868 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
869 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
870 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
871 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
872 		       struct ubi_ec_hdr *ec_hdr, int verbose);
873 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
874 			struct ubi_ec_hdr *ec_hdr);
875 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
876 			struct ubi_vid_hdr *vid_hdr, int verbose);
877 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
878 			 struct ubi_vid_hdr *vid_hdr);
879 
880 /* build.c */
881 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
882 		       int vid_hdr_offset, int max_beb_per1024);
883 int ubi_detach_mtd_dev(int ubi_num, int anyway);
884 struct ubi_device *ubi_get_device(int ubi_num);
885 void ubi_put_device(struct ubi_device *ubi);
886 struct ubi_device *ubi_get_by_major(int major);
887 int ubi_major2num(int major);
888 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
889 		      int ntype);
890 int ubi_notify_all(struct ubi_device *ubi, int ntype,
891 		   struct notifier_block *nb);
892 int ubi_enumerate_volumes(struct notifier_block *nb);
893 void ubi_free_internal_volumes(struct ubi_device *ubi);
894 
895 /* kapi.c */
896 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
897 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
898 			    struct ubi_volume_info *vi);
899 /* scan.c */
900 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
901 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
902 
903 /* fastmap.c */
904 #ifdef CONFIG_MTD_UBI_FASTMAP
905 size_t ubi_calc_fm_size(struct ubi_device *ubi);
906 int ubi_update_fastmap(struct ubi_device *ubi);
907 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
908 		     int fm_anchor);
909 #else
910 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
911 #endif
912 
913 /* block.c */
914 #ifdef CONFIG_MTD_UBI_BLOCK
915 int ubiblock_init(void);
916 void ubiblock_exit(void);
917 int ubiblock_create(struct ubi_volume_info *vi);
918 int ubiblock_remove(struct ubi_volume_info *vi);
919 #else
920 static inline int ubiblock_init(void) { return 0; }
921 static inline void ubiblock_exit(void) {}
922 static inline int ubiblock_create(struct ubi_volume_info *vi)
923 {
924 	return -ENOSYS;
925 }
926 static inline int ubiblock_remove(struct ubi_volume_info *vi)
927 {
928 	return -ENOSYS;
929 }
930 #endif
931 
932 /*
933  * ubi_for_each_free_peb - walk the UBI free RB tree.
934  * @ubi: UBI device description object
935  * @e: a pointer to a ubi_wl_entry to use as cursor
936  * @pos: a pointer to RB-tree entry type to use as a loop counter
937  */
938 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
939 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
940 
941 /*
942  * ubi_for_each_used_peb - walk the UBI used RB tree.
943  * @ubi: UBI device description object
944  * @e: a pointer to a ubi_wl_entry to use as cursor
945  * @pos: a pointer to RB-tree entry type to use as a loop counter
946  */
947 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
948 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
949 
950 /*
951  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
952  * @ubi: UBI device description object
953  * @e: a pointer to a ubi_wl_entry to use as cursor
954  * @pos: a pointer to RB-tree entry type to use as a loop counter
955  */
956 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
957 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
958 
959 /*
960  * ubi_for_each_protected_peb - walk the UBI protection queue.
961  * @ubi: UBI device description object
962  * @i: a integer used as counter
963  * @e: a pointer to a ubi_wl_entry to use as cursor
964  */
965 #define ubi_for_each_protected_peb(ubi, i, e)	\
966 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
967 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
968 
969 /*
970  * ubi_rb_for_each_entry - walk an RB-tree.
971  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
972  * @pos: a pointer to RB-tree entry type to use as a loop counter
973  * @root: RB-tree's root
974  * @member: the name of the 'struct rb_node' within the RB-tree entry
975  */
976 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
977 	for (rb = rb_first(root),                                            \
978 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
979 	     rb;                                                             \
980 	     rb = rb_next(rb),                                               \
981 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
982 
983 /*
984  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
985  *
986  * @av: volume attaching information
987  * @aeb: attaching eraseblock information
988  * @list: the list to move to
989  */
990 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
991 					 struct ubi_ainf_peb *aeb,
992 					 struct list_head *list)
993 {
994 		rb_erase(&aeb->u.rb, &av->root);
995 		list_add_tail(&aeb->u.list, list);
996 }
997 
998 /**
999  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
1000  * @ubi: UBI device description object
1001  * @gfp_flags: GFP flags to allocate with
1002  *
1003  * This function returns a pointer to the newly allocated and zero-filled
1004  * volume identifier header object in case of success and %NULL in case of
1005  * failure.
1006  */
1007 static inline struct ubi_vid_hdr *
1008 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
1009 {
1010 	void *vid_hdr;
1011 
1012 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
1013 	if (!vid_hdr)
1014 		return NULL;
1015 
1016 	/*
1017 	 * VID headers may be stored at un-aligned flash offsets, so we shift
1018 	 * the pointer.
1019 	 */
1020 	return vid_hdr + ubi->vid_hdr_shift;
1021 }
1022 
1023 /**
1024  * ubi_free_vid_hdr - free a volume identifier header object.
1025  * @ubi: UBI device description object
1026  * @vid_hdr: the object to free
1027  */
1028 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
1029 				    struct ubi_vid_hdr *vid_hdr)
1030 {
1031 	void *p = vid_hdr;
1032 
1033 	if (!p)
1034 		return;
1035 
1036 	kfree(p - ubi->vid_hdr_shift);
1037 }
1038 
1039 /*
1040  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1041  * the beginning of the logical eraseblock, not to the beginning of the
1042  * physical eraseblock.
1043  */
1044 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1045 				   int pnum, int offset, int len)
1046 {
1047 	ubi_assert(offset >= 0);
1048 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1049 }
1050 
1051 /*
1052  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1053  * the beginning of the logical eraseblock, not to the beginning of the
1054  * physical eraseblock.
1055  */
1056 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1057 				    int pnum, int offset, int len)
1058 {
1059 	ubi_assert(offset >= 0);
1060 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1061 }
1062 
1063 /**
1064  * ubi_ro_mode - switch to read-only mode.
1065  * @ubi: UBI device description object
1066  */
1067 static inline void ubi_ro_mode(struct ubi_device *ubi)
1068 {
1069 	if (!ubi->ro_mode) {
1070 		ubi->ro_mode = 1;
1071 		ubi_warn(ubi, "switch to read-only mode");
1072 		dump_stack();
1073 	}
1074 }
1075 
1076 /**
1077  * vol_id2idx - get table index by volume ID.
1078  * @ubi: UBI device description object
1079  * @vol_id: volume ID
1080  */
1081 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1082 {
1083 	if (vol_id >= UBI_INTERNAL_VOL_START)
1084 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1085 	else
1086 		return vol_id;
1087 }
1088 
1089 /**
1090  * idx2vol_id - get volume ID by table index.
1091  * @ubi: UBI device description object
1092  * @idx: table index
1093  */
1094 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1095 {
1096 	if (idx >= ubi->vtbl_slots)
1097 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1098 	else
1099 		return idx;
1100 }
1101 
1102 #endif /* !__UBI_UBI_H__ */
1103