xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 7587eb18)
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_wl_entry - wear-leveling entry.
171  * @u.rb: link in the corresponding (free/used) RB-tree
172  * @u.list: link in the protection queue
173  * @ec: erase counter
174  * @pnum: physical eraseblock number
175  *
176  * This data structure is used in the WL sub-system. Each physical eraseblock
177  * has a corresponding &struct wl_entry object which may be kept in different
178  * RB-trees. See WL sub-system for details.
179  */
180 struct ubi_wl_entry {
181 	union {
182 		struct rb_node rb;
183 		struct list_head list;
184 	} u;
185 	int ec;
186 	int pnum;
187 };
188 
189 /**
190  * struct ubi_ltree_entry - an entry in the lock tree.
191  * @rb: links RB-tree nodes
192  * @vol_id: volume ID of the locked logical eraseblock
193  * @lnum: locked logical eraseblock number
194  * @users: how many tasks are using this logical eraseblock or wait for it
195  * @mutex: read/write mutex to implement read/write access serialization to
196  *         the (@vol_id, @lnum) logical eraseblock
197  *
198  * This data structure is used in the EBA sub-system to implement per-LEB
199  * locking. When a logical eraseblock is being locked - corresponding
200  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
201  * See EBA sub-system for details.
202  */
203 struct ubi_ltree_entry {
204 	struct rb_node rb;
205 	int vol_id;
206 	int lnum;
207 	int users;
208 	struct rw_semaphore mutex;
209 };
210 
211 /**
212  * struct ubi_rename_entry - volume re-name description data structure.
213  * @new_name_len: new volume name length
214  * @new_name: new volume name
215  * @remove: if not zero, this volume should be removed, not re-named
216  * @desc: descriptor of the volume
217  * @list: links re-name entries into a list
218  *
219  * This data structure is utilized in the multiple volume re-name code. Namely,
220  * UBI first creates a list of &struct ubi_rename_entry objects from the
221  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
222  * the job.
223  */
224 struct ubi_rename_entry {
225 	int new_name_len;
226 	char new_name[UBI_VOL_NAME_MAX + 1];
227 	int remove;
228 	struct ubi_volume_desc *desc;
229 	struct list_head list;
230 };
231 
232 struct ubi_volume_desc;
233 
234 /**
235  * struct ubi_fastmap_layout - in-memory fastmap data structure.
236  * @e: PEBs used by the current fastmap
237  * @to_be_tortured: if non-zero tortured this PEB
238  * @used_blocks: number of used PEBs
239  * @max_pool_size: maximal size of the user pool
240  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
241  */
242 struct ubi_fastmap_layout {
243 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
244 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
245 	int used_blocks;
246 	int max_pool_size;
247 	int max_wl_pool_size;
248 };
249 
250 /**
251  * struct ubi_fm_pool - in-memory fastmap pool
252  * @pebs: PEBs in this pool
253  * @used: number of used PEBs
254  * @size: total number of PEBs in this pool
255  * @max_size: maximal size of the pool
256  *
257  * A pool gets filled with up to max_size.
258  * If all PEBs within the pool are used a new fastmap will be written
259  * to the flash and the pool gets refilled with empty PEBs.
260  *
261  */
262 struct ubi_fm_pool {
263 	int pebs[UBI_FM_MAX_POOL_SIZE];
264 	int used;
265 	int size;
266 	int max_size;
267 };
268 
269 /**
270  * struct ubi_volume - UBI volume description data structure.
271  * @dev: device object to make use of the the Linux device model
272  * @cdev: character device object to create character device
273  * @ubi: reference to the UBI device description object
274  * @vol_id: volume ID
275  * @ref_count: volume reference count
276  * @readers: number of users holding this volume in read-only mode
277  * @writers: number of users holding this volume in read-write mode
278  * @exclusive: whether somebody holds this volume in exclusive mode
279  * @metaonly: whether somebody is altering only meta data of this volume
280  *
281  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
282  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
283  * @usable_leb_size: logical eraseblock size without padding
284  * @used_ebs: how many logical eraseblocks in this volume contain data
285  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
286  * @used_bytes: how many bytes of data this volume contains
287  * @alignment: volume alignment
288  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
289  *            satisfy the requested alignment
290  * @name_len: volume name length
291  * @name: volume name
292  *
293  * @upd_ebs: how many eraseblocks are expected to be updated
294  * @ch_lnum: LEB number which is being changing by the atomic LEB change
295  *           operation
296  * @upd_bytes: how many bytes are expected to be received for volume update or
297  *             atomic LEB change
298  * @upd_received: how many bytes were already received for volume update or
299  *                atomic LEB change
300  * @upd_buf: update buffer which is used to collect update data or data for
301  *           atomic LEB change
302  *
303  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
304  * @checked: %1 if this static volume was checked
305  * @corrupted: %1 if the volume is corrupted (static volumes only)
306  * @upd_marker: %1 if the update marker is set for this volume
307  * @updating: %1 if the volume is being updated
308  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
309  * @direct_writes: %1 if direct writes are enabled for this volume
310  *
311  * The @corrupted field indicates that the volume's contents is corrupted.
312  * Since UBI protects only static volumes, this field is not relevant to
313  * dynamic volumes - it is user's responsibility to assure their data
314  * integrity.
315  *
316  * The @upd_marker flag indicates that this volume is either being updated at
317  * the moment or is damaged because of an unclean reboot.
318  */
319 struct ubi_volume {
320 	struct device dev;
321 	struct cdev cdev;
322 	struct ubi_device *ubi;
323 	int vol_id;
324 	int ref_count;
325 	int readers;
326 	int writers;
327 	int exclusive;
328 	int metaonly;
329 
330 	int reserved_pebs;
331 	int vol_type;
332 	int usable_leb_size;
333 	int used_ebs;
334 	int last_eb_bytes;
335 	long long used_bytes;
336 	int alignment;
337 	int data_pad;
338 	int name_len;
339 	char name[UBI_VOL_NAME_MAX + 1];
340 
341 	int upd_ebs;
342 	int ch_lnum;
343 	long long upd_bytes;
344 	long long upd_received;
345 	void *upd_buf;
346 
347 	int *eba_tbl;
348 	unsigned int checked:1;
349 	unsigned int corrupted:1;
350 	unsigned int upd_marker:1;
351 	unsigned int updating:1;
352 	unsigned int changing_leb:1;
353 	unsigned int direct_writes:1;
354 };
355 
356 /**
357  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
358  * @vol: reference to the corresponding volume description object
359  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
360  * or %UBI_METAONLY)
361  */
362 struct ubi_volume_desc {
363 	struct ubi_volume *vol;
364 	int mode;
365 };
366 
367 struct ubi_wl_entry;
368 
369 /**
370  * struct ubi_debug_info - debugging information for an UBI device.
371  *
372  * @chk_gen: if UBI general extra checks are enabled
373  * @chk_io: if UBI I/O extra checks are enabled
374  * @chk_fastmap: if UBI fastmap extra checks are enabled
375  * @disable_bgt: disable the background task for testing purposes
376  * @emulate_bitflips: emulate bit-flips for testing purposes
377  * @emulate_io_failures: emulate write/erase failures for testing purposes
378  * @emulate_power_cut: emulate power cut for testing purposes
379  * @power_cut_counter: count down for writes left until emulated power cut
380  * @power_cut_min: minimum number of writes before emulating a power cut
381  * @power_cut_max: maximum number of writes until emulating a power cut
382  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
383  * @dfs_dir: direntry object of the UBI device debugfs directory
384  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
385  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
386  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
387  * @dfs_disable_bgt: debugfs knob to disable the background task
388  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
389  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
390  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
391  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
392  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
393  */
394 struct ubi_debug_info {
395 	unsigned int chk_gen:1;
396 	unsigned int chk_io:1;
397 	unsigned int chk_fastmap:1;
398 	unsigned int disable_bgt:1;
399 	unsigned int emulate_bitflips:1;
400 	unsigned int emulate_io_failures:1;
401 	unsigned int emulate_power_cut:2;
402 	unsigned int power_cut_counter;
403 	unsigned int power_cut_min;
404 	unsigned int power_cut_max;
405 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
406 	struct dentry *dfs_dir;
407 	struct dentry *dfs_chk_gen;
408 	struct dentry *dfs_chk_io;
409 	struct dentry *dfs_chk_fastmap;
410 	struct dentry *dfs_disable_bgt;
411 	struct dentry *dfs_emulate_bitflips;
412 	struct dentry *dfs_emulate_io_failures;
413 	struct dentry *dfs_emulate_power_cut;
414 	struct dentry *dfs_power_cut_min;
415 	struct dentry *dfs_power_cut_max;
416 };
417 
418 /**
419  * struct ubi_device - UBI device description structure
420  * @dev: UBI device object to use the the Linux device model
421  * @cdev: character device object to create character device
422  * @ubi_num: UBI device number
423  * @ubi_name: UBI device name
424  * @vol_count: number of volumes in this UBI device
425  * @volumes: volumes of this UBI device
426  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
427  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
428  *                @vol->readers, @vol->writers, @vol->exclusive,
429  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
430  *                @vol->eba_tbl.
431  * @ref_count: count of references on the UBI device
432  * @image_seq: image sequence number recorded on EC headers
433  *
434  * @rsvd_pebs: count of reserved physical eraseblocks
435  * @avail_pebs: count of available physical eraseblocks
436  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
437  *                 handling
438  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
439  *
440  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
441  *                     of UBI initialization
442  * @vtbl_slots: how many slots are available in the volume table
443  * @vtbl_size: size of the volume table in bytes
444  * @vtbl: in-RAM volume table copy
445  * @device_mutex: protects on-flash volume table and serializes volume
446  *                creation, deletion, update, re-size, re-name and set
447  *                property
448  *
449  * @max_ec: current highest erase counter value
450  * @mean_ec: current mean erase counter value
451  *
452  * @global_sqnum: global sequence number
453  * @ltree_lock: protects the lock tree and @global_sqnum
454  * @ltree: the lock tree
455  * @alc_mutex: serializes "atomic LEB change" operations
456  *
457  * @fm_disabled: non-zero if fastmap is disabled (default)
458  * @fm: in-memory data structure of the currently used fastmap
459  * @fm_pool: in-memory data structure of the fastmap pool
460  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
461  *		sub-system
462  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
463  * that critical sections cannot be interrupted by ubi_update_fastmap()
464  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
465  * @fm_size: fastmap size in bytes
466  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
467  * @fm_work: fastmap work queue
468  * @fm_work_scheduled: non-zero if fastmap work was scheduled
469  * @fast_attach: non-zero if UBI was attached by fastmap
470  *
471  * @used: RB-tree of used physical eraseblocks
472  * @erroneous: RB-tree of erroneous used physical eraseblocks
473  * @free: RB-tree of free physical eraseblocks
474  * @free_count: Contains the number of elements in @free
475  * @scrub: RB-tree of physical eraseblocks which need scrubbing
476  * @pq: protection queue (contain physical eraseblocks which are temporarily
477  *      protected from the wear-leveling worker)
478  * @pq_head: protection queue head
479  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
480  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
481  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
482  *	     and @fm_wl_pool fields
483  * @move_mutex: serializes eraseblock moves
484  * @work_sem: used to wait for all the scheduled works to finish and prevent
485  * new works from being submitted
486  * @wl_scheduled: non-zero if the wear-leveling was scheduled
487  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
488  *             physical eraseblock
489  * @move_from: physical eraseblock from where the data is being moved
490  * @move_to: physical eraseblock where the data is being moved to
491  * @move_to_put: if the "to" PEB was put
492  * @works: list of pending works
493  * @works_count: count of pending works
494  * @bgt_thread: background thread description object
495  * @thread_enabled: if the background thread is enabled
496  * @bgt_name: background thread name
497  *
498  * @flash_size: underlying MTD device size (in bytes)
499  * @peb_count: count of physical eraseblocks on the MTD device
500  * @peb_size: physical eraseblock size
501  * @bad_peb_limit: top limit of expected bad physical eraseblocks
502  * @bad_peb_count: count of bad physical eraseblocks
503  * @good_peb_count: count of good physical eraseblocks
504  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
505  *                  used by UBI)
506  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
507  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
508  * @min_io_size: minimal input/output unit size of the underlying MTD device
509  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
510  * @ro_mode: if the UBI device is in read-only mode
511  * @leb_size: logical eraseblock size
512  * @leb_start: starting offset of logical eraseblocks within physical
513  *             eraseblocks
514  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
515  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
516  * @vid_hdr_offset: starting offset of the volume identifier header (might be
517  *                  unaligned)
518  * @vid_hdr_aloffset: starting offset of the VID header aligned to
519  *                    @hdrs_min_io_size
520  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
521  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
522  *               not
523  * @nor_flash: non-zero if working on top of NOR flash
524  * @max_write_size: maximum amount of bytes the underlying flash can write at a
525  *                  time (MTD write buffer size)
526  * @mtd: MTD device descriptor
527  *
528  * @peb_buf: a buffer of PEB size used for different purposes
529  * @buf_mutex: protects @peb_buf
530  * @ckvol_mutex: serializes static volume checking when opening
531  *
532  * @dbg: debugging information for this UBI device
533  */
534 struct ubi_device {
535 	struct cdev cdev;
536 	struct device dev;
537 	int ubi_num;
538 	char ubi_name[sizeof(UBI_NAME_STR)+5];
539 	int vol_count;
540 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
541 	spinlock_t volumes_lock;
542 	int ref_count;
543 	int image_seq;
544 
545 	int rsvd_pebs;
546 	int avail_pebs;
547 	int beb_rsvd_pebs;
548 	int beb_rsvd_level;
549 	int bad_peb_limit;
550 
551 	int autoresize_vol_id;
552 	int vtbl_slots;
553 	int vtbl_size;
554 	struct ubi_vtbl_record *vtbl;
555 	struct mutex device_mutex;
556 
557 	int max_ec;
558 	/* Note, mean_ec is not updated run-time - should be fixed */
559 	int mean_ec;
560 
561 	/* EBA sub-system's stuff */
562 	unsigned long long global_sqnum;
563 	spinlock_t ltree_lock;
564 	struct rb_root ltree;
565 	struct mutex alc_mutex;
566 
567 	/* Fastmap stuff */
568 	int fm_disabled;
569 	struct ubi_fastmap_layout *fm;
570 	struct ubi_fm_pool fm_pool;
571 	struct ubi_fm_pool fm_wl_pool;
572 	struct rw_semaphore fm_eba_sem;
573 	struct rw_semaphore fm_protect;
574 	void *fm_buf;
575 	size_t fm_size;
576 	struct work_struct fm_work;
577 	int fm_work_scheduled;
578 	int fast_attach;
579 
580 	/* Wear-leveling sub-system's stuff */
581 	struct rb_root used;
582 	struct rb_root erroneous;
583 	struct rb_root free;
584 	int free_count;
585 	struct rb_root scrub;
586 	struct list_head pq[UBI_PROT_QUEUE_LEN];
587 	int pq_head;
588 	spinlock_t wl_lock;
589 	struct mutex move_mutex;
590 	struct rw_semaphore work_sem;
591 	int wl_scheduled;
592 	struct ubi_wl_entry **lookuptbl;
593 	struct ubi_wl_entry *move_from;
594 	struct ubi_wl_entry *move_to;
595 	int move_to_put;
596 	struct list_head works;
597 	int works_count;
598 	struct task_struct *bgt_thread;
599 	int thread_enabled;
600 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
601 
602 	/* I/O sub-system's stuff */
603 	long long flash_size;
604 	int peb_count;
605 	int peb_size;
606 	int bad_peb_count;
607 	int good_peb_count;
608 	int corr_peb_count;
609 	int erroneous_peb_count;
610 	int max_erroneous;
611 	int min_io_size;
612 	int hdrs_min_io_size;
613 	int ro_mode;
614 	int leb_size;
615 	int leb_start;
616 	int ec_hdr_alsize;
617 	int vid_hdr_alsize;
618 	int vid_hdr_offset;
619 	int vid_hdr_aloffset;
620 	int vid_hdr_shift;
621 	unsigned int bad_allowed:1;
622 	unsigned int nor_flash:1;
623 	int max_write_size;
624 	struct mtd_info *mtd;
625 
626 	void *peb_buf;
627 	struct mutex buf_mutex;
628 	struct mutex ckvol_mutex;
629 
630 	struct ubi_debug_info dbg;
631 };
632 
633 /**
634  * struct ubi_ainf_peb - attach information about a physical eraseblock.
635  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
636  * @pnum: physical eraseblock number
637  * @vol_id: ID of the volume this LEB belongs to
638  * @lnum: logical eraseblock number
639  * @scrub: if this physical eraseblock needs scrubbing
640  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
641  * @sqnum: sequence number
642  * @u: unions RB-tree or @list links
643  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
644  * @u.list: link in one of the eraseblock lists
645  *
646  * One object of this type is allocated for each physical eraseblock when
647  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
648  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
649  */
650 struct ubi_ainf_peb {
651 	int ec;
652 	int pnum;
653 	int vol_id;
654 	int lnum;
655 	unsigned int scrub:1;
656 	unsigned int copy_flag:1;
657 	unsigned long long sqnum;
658 	union {
659 		struct rb_node rb;
660 		struct list_head list;
661 	} u;
662 };
663 
664 /**
665  * struct ubi_ainf_volume - attaching information about a volume.
666  * @vol_id: volume ID
667  * @highest_lnum: highest logical eraseblock number in this volume
668  * @leb_count: number of logical eraseblocks in this volume
669  * @vol_type: volume type
670  * @used_ebs: number of used logical eraseblocks in this volume (only for
671  *            static volumes)
672  * @last_data_size: amount of data in the last logical eraseblock of this
673  *                  volume (always equivalent to the usable logical eraseblock
674  *                  size in case of dynamic volumes)
675  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
676  *            are not used (due to volume alignment)
677  * @compat: compatibility flags of this volume
678  * @rb: link in the volume RB-tree
679  * @root: root of the RB-tree containing all the eraseblock belonging to this
680  *        volume (&struct ubi_ainf_peb objects)
681  *
682  * One object of this type is allocated for each volume when attaching an MTD
683  * device.
684  */
685 struct ubi_ainf_volume {
686 	int vol_id;
687 	int highest_lnum;
688 	int leb_count;
689 	int vol_type;
690 	int used_ebs;
691 	int last_data_size;
692 	int data_pad;
693 	int compat;
694 	struct rb_node rb;
695 	struct rb_root root;
696 };
697 
698 /**
699  * struct ubi_attach_info - MTD device attaching information.
700  * @volumes: root of the volume RB-tree
701  * @corr: list of corrupted physical eraseblocks
702  * @free: list of free physical eraseblocks
703  * @erase: list of physical eraseblocks which have to be erased
704  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
705  *         those belonging to "preserve"-compatible internal volumes)
706  * @corr_peb_count: count of PEBs in the @corr list
707  * @empty_peb_count: count of PEBs which are presumably empty (contain only
708  *                   0xFF bytes)
709  * @alien_peb_count: count of PEBs in the @alien list
710  * @bad_peb_count: count of bad physical eraseblocks
711  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
712  *                       as bad yet, but which look like bad
713  * @vols_found: number of volumes found
714  * @highest_vol_id: highest volume ID
715  * @is_empty: flag indicating whether the MTD device is empty or not
716  * @min_ec: lowest erase counter value
717  * @max_ec: highest erase counter value
718  * @max_sqnum: highest sequence number value
719  * @mean_ec: mean erase counter value
720  * @ec_sum: a temporary variable used when calculating @mean_ec
721  * @ec_count: a temporary variable used when calculating @mean_ec
722  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
723  *
724  * This data structure contains the result of attaching an MTD device and may
725  * be used by other UBI sub-systems to build final UBI data structures, further
726  * error-recovery and so on.
727  */
728 struct ubi_attach_info {
729 	struct rb_root volumes;
730 	struct list_head corr;
731 	struct list_head free;
732 	struct list_head erase;
733 	struct list_head alien;
734 	int corr_peb_count;
735 	int empty_peb_count;
736 	int alien_peb_count;
737 	int bad_peb_count;
738 	int maybe_bad_peb_count;
739 	int vols_found;
740 	int highest_vol_id;
741 	int is_empty;
742 	int min_ec;
743 	int max_ec;
744 	unsigned long long max_sqnum;
745 	int mean_ec;
746 	uint64_t ec_sum;
747 	int ec_count;
748 	struct kmem_cache *aeb_slab_cache;
749 };
750 
751 /**
752  * struct ubi_work - UBI work description data structure.
753  * @list: a link in the list of pending works
754  * @func: worker function
755  * @e: physical eraseblock to erase
756  * @vol_id: the volume ID on which this erasure is being performed
757  * @lnum: the logical eraseblock number
758  * @torture: if the physical eraseblock has to be tortured
759  * @anchor: produce a anchor PEB to by used by fastmap
760  *
761  * The @func pointer points to the worker function. If the @shutdown argument is
762  * not zero, the worker has to free the resources and exit immediately as the
763  * WL sub-system is shutting down.
764  * The worker has to return zero in case of success and a negative error code in
765  * case of failure.
766  */
767 struct ubi_work {
768 	struct list_head list;
769 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
770 	/* The below fields are only relevant to erasure works */
771 	struct ubi_wl_entry *e;
772 	int vol_id;
773 	int lnum;
774 	int torture;
775 	int anchor;
776 };
777 
778 #include "debug.h"
779 
780 extern struct kmem_cache *ubi_wl_entry_slab;
781 extern const struct file_operations ubi_ctrl_cdev_operations;
782 extern const struct file_operations ubi_cdev_operations;
783 extern const struct file_operations ubi_vol_cdev_operations;
784 extern struct class ubi_class;
785 extern struct mutex ubi_devices_mutex;
786 extern struct blocking_notifier_head ubi_notifiers;
787 
788 /* attach.c */
789 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
790 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
791 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
792 				    int vol_id);
793 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
794 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
795 				       struct ubi_attach_info *ai);
796 int ubi_attach(struct ubi_device *ubi, int force_scan);
797 void ubi_destroy_ai(struct ubi_attach_info *ai);
798 
799 /* vtbl.c */
800 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
801 			   struct ubi_vtbl_record *vtbl_rec);
802 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
803 			    struct list_head *rename_list);
804 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
805 
806 /* vmt.c */
807 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
808 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
809 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
810 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
811 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
812 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
813 
814 /* upd.c */
815 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
816 		     long long bytes);
817 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
818 			 const void __user *buf, int count);
819 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
820 			 const struct ubi_leb_change_req *req);
821 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
822 			     const void __user *buf, int count);
823 
824 /* misc.c */
825 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
826 		      int length);
827 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
828 void ubi_update_reserved(struct ubi_device *ubi);
829 void ubi_calculate_reserved(struct ubi_device *ubi);
830 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
831 
832 /* eba.c */
833 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
834 		      int lnum);
835 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
836 		     void *buf, int offset, int len, int check);
837 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
838 			struct ubi_sgl *sgl, int lnum, int offset, int len,
839 			int check);
840 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
841 		      const void *buf, int offset, int len);
842 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
843 			 int lnum, const void *buf, int len, int used_ebs);
844 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
845 			      int lnum, const void *buf, int len);
846 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
847 		     struct ubi_vid_hdr *vid_hdr);
848 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
849 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
850 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
851 		   struct ubi_attach_info *ai_scan);
852 
853 /* wl.c */
854 int ubi_wl_get_peb(struct ubi_device *ubi);
855 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
856 		   int pnum, int torture);
857 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
858 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
859 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
860 void ubi_wl_close(struct ubi_device *ubi);
861 int ubi_thread(void *u);
862 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
863 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
864 		      int lnum, int torture);
865 int ubi_is_erase_work(struct ubi_work *wrk);
866 void ubi_refill_pools(struct ubi_device *ubi);
867 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
868 
869 /* io.c */
870 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
871 		int len);
872 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
873 		 int len);
874 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
875 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
876 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
877 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
878 		       struct ubi_ec_hdr *ec_hdr, int verbose);
879 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
880 			struct ubi_ec_hdr *ec_hdr);
881 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
882 			struct ubi_vid_hdr *vid_hdr, int verbose);
883 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
884 			 struct ubi_vid_hdr *vid_hdr);
885 
886 /* build.c */
887 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
888 		       int vid_hdr_offset, int max_beb_per1024);
889 int ubi_detach_mtd_dev(int ubi_num, int anyway);
890 struct ubi_device *ubi_get_device(int ubi_num);
891 void ubi_put_device(struct ubi_device *ubi);
892 struct ubi_device *ubi_get_by_major(int major);
893 int ubi_major2num(int major);
894 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
895 		      int ntype);
896 int ubi_notify_all(struct ubi_device *ubi, int ntype,
897 		   struct notifier_block *nb);
898 int ubi_enumerate_volumes(struct notifier_block *nb);
899 void ubi_free_internal_volumes(struct ubi_device *ubi);
900 
901 /* kapi.c */
902 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
903 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
904 			    struct ubi_volume_info *vi);
905 /* scan.c */
906 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
907 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
908 
909 /* fastmap.c */
910 #ifdef CONFIG_MTD_UBI_FASTMAP
911 size_t ubi_calc_fm_size(struct ubi_device *ubi);
912 int ubi_update_fastmap(struct ubi_device *ubi);
913 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
914 		     int fm_anchor);
915 #else
916 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
917 #endif
918 
919 /* block.c */
920 #ifdef CONFIG_MTD_UBI_BLOCK
921 int ubiblock_init(void);
922 void ubiblock_exit(void);
923 int ubiblock_create(struct ubi_volume_info *vi);
924 int ubiblock_remove(struct ubi_volume_info *vi);
925 #else
926 static inline int ubiblock_init(void) { return 0; }
927 static inline void ubiblock_exit(void) {}
928 static inline int ubiblock_create(struct ubi_volume_info *vi)
929 {
930 	return -ENOSYS;
931 }
932 static inline int ubiblock_remove(struct ubi_volume_info *vi)
933 {
934 	return -ENOSYS;
935 }
936 #endif
937 
938 /*
939  * ubi_for_each_free_peb - walk the UBI free RB tree.
940  * @ubi: UBI device description object
941  * @e: a pointer to a ubi_wl_entry to use as cursor
942  * @pos: a pointer to RB-tree entry type to use as a loop counter
943  */
944 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
945 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
946 
947 /*
948  * ubi_for_each_used_peb - walk the UBI used RB tree.
949  * @ubi: UBI device description object
950  * @e: a pointer to a ubi_wl_entry to use as cursor
951  * @pos: a pointer to RB-tree entry type to use as a loop counter
952  */
953 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
954 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
955 
956 /*
957  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
958  * @ubi: UBI device description object
959  * @e: a pointer to a ubi_wl_entry to use as cursor
960  * @pos: a pointer to RB-tree entry type to use as a loop counter
961  */
962 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
963 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
964 
965 /*
966  * ubi_for_each_protected_peb - walk the UBI protection queue.
967  * @ubi: UBI device description object
968  * @i: a integer used as counter
969  * @e: a pointer to a ubi_wl_entry to use as cursor
970  */
971 #define ubi_for_each_protected_peb(ubi, i, e)	\
972 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
973 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
974 
975 /*
976  * ubi_rb_for_each_entry - walk an RB-tree.
977  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
978  * @pos: a pointer to RB-tree entry type to use as a loop counter
979  * @root: RB-tree's root
980  * @member: the name of the 'struct rb_node' within the RB-tree entry
981  */
982 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
983 	for (rb = rb_first(root),                                            \
984 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
985 	     rb;                                                             \
986 	     rb = rb_next(rb),                                               \
987 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
988 
989 /*
990  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
991  *
992  * @av: volume attaching information
993  * @aeb: attaching eraseblock information
994  * @list: the list to move to
995  */
996 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
997 					 struct ubi_ainf_peb *aeb,
998 					 struct list_head *list)
999 {
1000 		rb_erase(&aeb->u.rb, &av->root);
1001 		list_add_tail(&aeb->u.list, list);
1002 }
1003 
1004 /**
1005  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
1006  * @ubi: UBI device description object
1007  * @gfp_flags: GFP flags to allocate with
1008  *
1009  * This function returns a pointer to the newly allocated and zero-filled
1010  * volume identifier header object in case of success and %NULL in case of
1011  * failure.
1012  */
1013 static inline struct ubi_vid_hdr *
1014 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
1015 {
1016 	void *vid_hdr;
1017 
1018 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
1019 	if (!vid_hdr)
1020 		return NULL;
1021 
1022 	/*
1023 	 * VID headers may be stored at un-aligned flash offsets, so we shift
1024 	 * the pointer.
1025 	 */
1026 	return vid_hdr + ubi->vid_hdr_shift;
1027 }
1028 
1029 /**
1030  * ubi_free_vid_hdr - free a volume identifier header object.
1031  * @ubi: UBI device description object
1032  * @vid_hdr: the object to free
1033  */
1034 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
1035 				    struct ubi_vid_hdr *vid_hdr)
1036 {
1037 	void *p = vid_hdr;
1038 
1039 	if (!p)
1040 		return;
1041 
1042 	kfree(p - ubi->vid_hdr_shift);
1043 }
1044 
1045 /*
1046  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1047  * the beginning of the logical eraseblock, not to the beginning of the
1048  * physical eraseblock.
1049  */
1050 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1051 				   int pnum, int offset, int len)
1052 {
1053 	ubi_assert(offset >= 0);
1054 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1055 }
1056 
1057 /*
1058  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1059  * the beginning of the logical eraseblock, not to the beginning of the
1060  * physical eraseblock.
1061  */
1062 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1063 				    int pnum, int offset, int len)
1064 {
1065 	ubi_assert(offset >= 0);
1066 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1067 }
1068 
1069 /**
1070  * ubi_ro_mode - switch to read-only mode.
1071  * @ubi: UBI device description object
1072  */
1073 static inline void ubi_ro_mode(struct ubi_device *ubi)
1074 {
1075 	if (!ubi->ro_mode) {
1076 		ubi->ro_mode = 1;
1077 		ubi_warn(ubi, "switch to read-only mode");
1078 		dump_stack();
1079 	}
1080 }
1081 
1082 /**
1083  * vol_id2idx - get table index by volume ID.
1084  * @ubi: UBI device description object
1085  * @vol_id: volume ID
1086  */
1087 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1088 {
1089 	if (vol_id >= UBI_INTERNAL_VOL_START)
1090 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1091 	else
1092 		return vol_id;
1093 }
1094 
1095 /**
1096  * idx2vol_id - get volume ID by table index.
1097  * @ubi: UBI device description object
1098  * @idx: table index
1099  */
1100 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1101 {
1102 	if (idx >= ubi->vtbl_slots)
1103 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1104 	else
1105 		return idx;
1106 }
1107 
1108 #endif /* !__UBI_UBI_H__ */
1109