xref: /openbmc/u-boot/drivers/mtd/ubi/ubi.h (revision cbd2fba1)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) International Business Machines Corp., 2006
4  * Copyright (c) Nokia Corporation, 2006, 2007
5  *
6  * Author: Artem Bityutskiy (Битюцкий Артём)
7  */
8 
9 #ifndef __UBI_UBI_H__
10 #define __UBI_UBI_H__
11 
12 #ifndef __UBOOT__
13 #include <linux/types.h>
14 #include <linux/list.h>
15 #include <linux/rbtree.h>
16 #include <linux/sched.h>
17 #include <linux/wait.h>
18 #include <linux/mutex.h>
19 #include <linux/rwsem.h>
20 #include <linux/spinlock.h>
21 #include <linux/fs.h>
22 #include <linux/cdev.h>
23 #include <linux/device.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
26 #include <linux/vmalloc.h>
27 #include <linux/notifier.h>
28 #include <asm/pgtable.h>
29 #else
30 #include <ubi_uboot.h>
31 #endif
32 #include <linux/mtd/mtd.h>
33 #include <linux/mtd/ubi.h>
34 #include "ubi-media.h"
35 #include <mtd/ubi-user.h>
36 
37 /* Maximum number of supported UBI devices */
38 #define UBI_MAX_DEVICES 32
39 
40 /* UBI name used for character devices, sysfs, etc */
41 #define UBI_NAME_STR "ubi"
42 
43 /* Normal UBI messages */
44 #ifdef CONFIG_UBI_SILENCE_MSG
45 #define ubi_msg(ubi, fmt, ...)
46 #else
47 #define ubi_msg(ubi, fmt, ...) printk(UBI_NAME_STR "%d: " fmt "\n", \
48 					 ubi->ubi_num, ##__VA_ARGS__)
49 #endif
50 
51 /* UBI warning messages */
52 #define ubi_warn(ubi, fmt, ...) pr_warn(UBI_NAME_STR "%d warning: %s: " fmt "\n", \
53 					ubi->ubi_num, __func__, ##__VA_ARGS__)
54 /* UBI error messages */
55 #define ubi_err(ubi, fmt, ...) pr_err(UBI_NAME_STR "%d error: %s: " fmt "\n", \
56 				      ubi->ubi_num, __func__, ##__VA_ARGS__)
57 
58 /* Background thread name pattern */
59 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
60 
61 /*
62  * This marker in the EBA table means that the LEB is um-mapped.
63  * NOTE! It has to have the same value as %UBI_ALL.
64  */
65 #define UBI_LEB_UNMAPPED -1
66 
67 /*
68  * In case of errors, UBI tries to repeat the operation several times before
69  * returning error. The below constant defines how many times UBI re-tries.
70  */
71 #define UBI_IO_RETRIES 3
72 
73 /*
74  * Length of the protection queue. The length is effectively equivalent to the
75  * number of (global) erase cycles PEBs are protected from the wear-leveling
76  * worker.
77  */
78 #define UBI_PROT_QUEUE_LEN 10
79 
80 /* The volume ID/LEB number/erase counter is unknown */
81 #define UBI_UNKNOWN -1
82 
83 /*
84  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
85  * + 2 for the number plus 1 for the trailing zero byte.
86  */
87 #define UBI_DFS_DIR_NAME "ubi%d"
88 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
89 
90 /*
91  * Error codes returned by the I/O sub-system.
92  *
93  * UBI_IO_FF: the read region of flash contains only 0xFFs
94  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
95  *                     integrity error reported by the MTD driver
96  *                     (uncorrectable ECC error in case of NAND)
97  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
98  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
99  *                         data integrity error reported by the MTD driver
100  *                         (uncorrectable ECC error in case of NAND)
101  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
102  *
103  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
104  * be or'ed with other error code. But this is a big change because there are
105  * may callers, so it does not worth the risk of introducing a bug
106  */
107 enum {
108 	UBI_IO_FF = 1,
109 	UBI_IO_FF_BITFLIPS,
110 	UBI_IO_BAD_HDR,
111 	UBI_IO_BAD_HDR_EBADMSG,
112 	UBI_IO_BITFLIPS,
113 };
114 
115 /*
116  * Return codes of the 'ubi_eba_copy_leb()' function.
117  *
118  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
119  *                   PEB was put meanwhile, or there is I/O on the source PEB
120  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
121  *                     PEB
122  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
123  *                     PEB
124  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
125  *                     PEB
126  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
127  *                       target PEB
128  * MOVE_RETRY: retry scrubbing the PEB
129  */
130 enum {
131 	MOVE_CANCEL_RACE = 1,
132 	MOVE_SOURCE_RD_ERR,
133 	MOVE_TARGET_RD_ERR,
134 	MOVE_TARGET_WR_ERR,
135 	MOVE_TARGET_BITFLIPS,
136 	MOVE_RETRY,
137 };
138 
139 /*
140  * Return codes of the fastmap sub-system
141  *
142  * UBI_NO_FASTMAP: No fastmap super block was found
143  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
144  */
145 enum {
146 	UBI_NO_FASTMAP = 1,
147 	UBI_BAD_FASTMAP,
148 };
149 
150 /*
151  * Flags for emulate_power_cut in ubi_debug_info
152  *
153  * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
154  * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
155  */
156 enum {
157 	POWER_CUT_EC_WRITE = 0x01,
158 	POWER_CUT_VID_WRITE = 0x02,
159 };
160 
161 /**
162  * struct ubi_wl_entry - wear-leveling entry.
163  * @u.rb: link in the corresponding (free/used) RB-tree
164  * @u.list: link in the protection queue
165  * @ec: erase counter
166  * @pnum: physical eraseblock number
167  *
168  * This data structure is used in the WL sub-system. Each physical eraseblock
169  * has a corresponding &struct wl_entry object which may be kept in different
170  * RB-trees. See WL sub-system for details.
171  */
172 struct ubi_wl_entry {
173 	union {
174 		struct rb_node rb;
175 		struct list_head list;
176 	} u;
177 	int ec;
178 	int pnum;
179 };
180 
181 /**
182  * struct ubi_ltree_entry - an entry in the lock tree.
183  * @rb: links RB-tree nodes
184  * @vol_id: volume ID of the locked logical eraseblock
185  * @lnum: locked logical eraseblock number
186  * @users: how many tasks are using this logical eraseblock or wait for it
187  * @mutex: read/write mutex to implement read/write access serialization to
188  *         the (@vol_id, @lnum) logical eraseblock
189  *
190  * This data structure is used in the EBA sub-system to implement per-LEB
191  * locking. When a logical eraseblock is being locked - corresponding
192  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
193  * See EBA sub-system for details.
194  */
195 struct ubi_ltree_entry {
196 	struct rb_node rb;
197 	int vol_id;
198 	int lnum;
199 	int users;
200 	struct rw_semaphore mutex;
201 };
202 
203 /**
204  * struct ubi_rename_entry - volume re-name description data structure.
205  * @new_name_len: new volume name length
206  * @new_name: new volume name
207  * @remove: if not zero, this volume should be removed, not re-named
208  * @desc: descriptor of the volume
209  * @list: links re-name entries into a list
210  *
211  * This data structure is utilized in the multiple volume re-name code. Namely,
212  * UBI first creates a list of &struct ubi_rename_entry objects from the
213  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
214  * the job.
215  */
216 struct ubi_rename_entry {
217 	int new_name_len;
218 	char new_name[UBI_VOL_NAME_MAX + 1];
219 	int remove;
220 	struct ubi_volume_desc *desc;
221 	struct list_head list;
222 };
223 
224 struct ubi_volume_desc;
225 
226 /**
227  * struct ubi_fastmap_layout - in-memory fastmap data structure.
228  * @e: PEBs used by the current fastmap
229  * @to_be_tortured: if non-zero tortured this PEB
230  * @used_blocks: number of used PEBs
231  * @max_pool_size: maximal size of the user pool
232  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
233  */
234 struct ubi_fastmap_layout {
235 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
236 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
237 	int used_blocks;
238 	int max_pool_size;
239 	int max_wl_pool_size;
240 };
241 
242 /**
243  * struct ubi_fm_pool - in-memory fastmap pool
244  * @pebs: PEBs in this pool
245  * @used: number of used PEBs
246  * @size: total number of PEBs in this pool
247  * @max_size: maximal size of the pool
248  *
249  * A pool gets filled with up to max_size.
250  * If all PEBs within the pool are used a new fastmap will be written
251  * to the flash and the pool gets refilled with empty PEBs.
252  *
253  */
254 struct ubi_fm_pool {
255 	int pebs[UBI_FM_MAX_POOL_SIZE];
256 	int used;
257 	int size;
258 	int max_size;
259 };
260 
261 /**
262  * struct ubi_volume - UBI volume description data structure.
263  * @dev: device object to make use of the the Linux device model
264  * @cdev: character device object to create character device
265  * @ubi: reference to the UBI device description object
266  * @vol_id: volume ID
267  * @ref_count: volume reference count
268  * @readers: number of users holding this volume in read-only mode
269  * @writers: number of users holding this volume in read-write mode
270  * @exclusive: whether somebody holds this volume in exclusive mode
271  * @metaonly: whether somebody is altering only meta data of this volume
272  *
273  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
274  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
275  * @usable_leb_size: logical eraseblock size without padding
276  * @used_ebs: how many logical eraseblocks in this volume contain data
277  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
278  * @used_bytes: how many bytes of data this volume contains
279  * @alignment: volume alignment
280  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
281  *            satisfy the requested alignment
282  * @name_len: volume name length
283  * @name: volume name
284  *
285  * @upd_ebs: how many eraseblocks are expected to be updated
286  * @ch_lnum: LEB number which is being changing by the atomic LEB change
287  *           operation
288  * @upd_bytes: how many bytes are expected to be received for volume update or
289  *             atomic LEB change
290  * @upd_received: how many bytes were already received for volume update or
291  *                atomic LEB change
292  * @upd_buf: update buffer which is used to collect update data or data for
293  *           atomic LEB change
294  *
295  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
296  * @checked: %1 if this static volume was checked
297  * @corrupted: %1 if the volume is corrupted (static volumes only)
298  * @upd_marker: %1 if the update marker is set for this volume
299  * @updating: %1 if the volume is being updated
300  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
301  * @direct_writes: %1 if direct writes are enabled for this volume
302  *
303  * The @corrupted field indicates that the volume's contents is corrupted.
304  * Since UBI protects only static volumes, this field is not relevant to
305  * dynamic volumes - it is user's responsibility to assure their data
306  * integrity.
307  *
308  * The @upd_marker flag indicates that this volume is either being updated at
309  * the moment or is damaged because of an unclean reboot.
310  */
311 struct ubi_volume {
312 	struct device dev;
313 	struct cdev cdev;
314 	struct ubi_device *ubi;
315 	int vol_id;
316 	int ref_count;
317 	int readers;
318 	int writers;
319 	int exclusive;
320 	int metaonly;
321 
322 	int reserved_pebs;
323 	int vol_type;
324 	int usable_leb_size;
325 	int used_ebs;
326 #ifndef __UBOOT__
327 	int last_eb_bytes;
328 #else
329 	u32 last_eb_bytes;
330 #endif
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 #ifndef __UBOOT__
572 	struct work_struct fm_work;
573 #endif
574 	int fm_work_scheduled;
575 
576 	/* Wear-leveling sub-system's stuff */
577 	struct rb_root used;
578 	struct rb_root erroneous;
579 	struct rb_root free;
580 	int free_count;
581 	struct rb_root scrub;
582 	struct list_head pq[UBI_PROT_QUEUE_LEN];
583 	int pq_head;
584 	spinlock_t wl_lock;
585 	struct mutex move_mutex;
586 	struct rw_semaphore work_sem;
587 	int wl_scheduled;
588 	struct ubi_wl_entry **lookuptbl;
589 	struct ubi_wl_entry *move_from;
590 	struct ubi_wl_entry *move_to;
591 	int move_to_put;
592 	struct list_head works;
593 	int works_count;
594 	struct task_struct *bgt_thread;
595 	int thread_enabled;
596 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
597 
598 	/* I/O sub-system's stuff */
599 	long long flash_size;
600 	int peb_count;
601 	int peb_size;
602 	int bad_peb_count;
603 	int good_peb_count;
604 	int corr_peb_count;
605 	int erroneous_peb_count;
606 	int max_erroneous;
607 	int min_io_size;
608 	int hdrs_min_io_size;
609 	int ro_mode;
610 	int leb_size;
611 	int leb_start;
612 	int ec_hdr_alsize;
613 	int vid_hdr_alsize;
614 	int vid_hdr_offset;
615 	int vid_hdr_aloffset;
616 	int vid_hdr_shift;
617 	unsigned int bad_allowed:1;
618 	unsigned int nor_flash:1;
619 	int max_write_size;
620 	struct mtd_info *mtd;
621 
622 	void *peb_buf;
623 	struct mutex buf_mutex;
624 	struct mutex ckvol_mutex;
625 
626 	struct ubi_debug_info dbg;
627 };
628 
629 /**
630  * struct ubi_ainf_peb - attach information about a physical eraseblock.
631  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
632  * @pnum: physical eraseblock number
633  * @vol_id: ID of the volume this LEB belongs to
634  * @lnum: logical eraseblock number
635  * @scrub: if this physical eraseblock needs scrubbing
636  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
637  * @sqnum: sequence number
638  * @u: unions RB-tree or @list links
639  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
640  * @u.list: link in one of the eraseblock lists
641  *
642  * One object of this type is allocated for each physical eraseblock when
643  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
644  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
645  */
646 struct ubi_ainf_peb {
647 	int ec;
648 	int pnum;
649 	int vol_id;
650 	int lnum;
651 	unsigned int scrub:1;
652 	unsigned int copy_flag:1;
653 	unsigned long long sqnum;
654 	union {
655 		struct rb_node rb;
656 		struct list_head list;
657 	} u;
658 };
659 
660 /**
661  * struct ubi_ainf_volume - attaching information about a volume.
662  * @vol_id: volume ID
663  * @highest_lnum: highest logical eraseblock number in this volume
664  * @leb_count: number of logical eraseblocks in this volume
665  * @vol_type: volume type
666  * @used_ebs: number of used logical eraseblocks in this volume (only for
667  *            static volumes)
668  * @last_data_size: amount of data in the last logical eraseblock of this
669  *                  volume (always equivalent to the usable logical eraseblock
670  *                  size in case of dynamic volumes)
671  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
672  *            are not used (due to volume alignment)
673  * @compat: compatibility flags of this volume
674  * @rb: link in the volume RB-tree
675  * @root: root of the RB-tree containing all the eraseblock belonging to this
676  *        volume (&struct ubi_ainf_peb objects)
677  *
678  * One object of this type is allocated for each volume when attaching an MTD
679  * device.
680  */
681 struct ubi_ainf_volume {
682 	int vol_id;
683 	int highest_lnum;
684 	int leb_count;
685 	int vol_type;
686 	int used_ebs;
687 	int last_data_size;
688 	int data_pad;
689 	int compat;
690 	struct rb_node rb;
691 	struct rb_root root;
692 };
693 
694 /**
695  * struct ubi_attach_info - MTD device attaching information.
696  * @volumes: root of the volume RB-tree
697  * @corr: list of corrupted physical eraseblocks
698  * @free: list of free physical eraseblocks
699  * @erase: list of physical eraseblocks which have to be erased
700  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
701  *         those belonging to "preserve"-compatible internal volumes)
702  * @corr_peb_count: count of PEBs in the @corr list
703  * @empty_peb_count: count of PEBs which are presumably empty (contain only
704  *                   0xFF bytes)
705  * @alien_peb_count: count of PEBs in the @alien list
706  * @bad_peb_count: count of bad physical eraseblocks
707  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
708  *                       as bad yet, but which look like bad
709  * @vols_found: number of volumes found
710  * @highest_vol_id: highest volume ID
711  * @is_empty: flag indicating whether the MTD device is empty or not
712  * @min_ec: lowest erase counter value
713  * @max_ec: highest erase counter value
714  * @max_sqnum: highest sequence number value
715  * @mean_ec: mean erase counter value
716  * @ec_sum: a temporary variable used when calculating @mean_ec
717  * @ec_count: a temporary variable used when calculating @mean_ec
718  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
719  *
720  * This data structure contains the result of attaching an MTD device and may
721  * be used by other UBI sub-systems to build final UBI data structures, further
722  * error-recovery and so on.
723  */
724 struct ubi_attach_info {
725 	struct rb_root volumes;
726 	struct list_head corr;
727 	struct list_head free;
728 	struct list_head erase;
729 	struct list_head alien;
730 	int corr_peb_count;
731 	int empty_peb_count;
732 	int alien_peb_count;
733 	int bad_peb_count;
734 	int maybe_bad_peb_count;
735 	int vols_found;
736 	int highest_vol_id;
737 	int is_empty;
738 	int min_ec;
739 	int max_ec;
740 	unsigned long long max_sqnum;
741 	int mean_ec;
742 	uint64_t ec_sum;
743 	int ec_count;
744 	struct kmem_cache *aeb_slab_cache;
745 };
746 
747 /**
748  * struct ubi_work - UBI work description data structure.
749  * @list: a link in the list of pending works
750  * @func: worker function
751  * @e: physical eraseblock to erase
752  * @vol_id: the volume ID on which this erasure is being performed
753  * @lnum: the logical eraseblock number
754  * @torture: if the physical eraseblock has to be tortured
755  * @anchor: produce a anchor PEB to by used by fastmap
756  *
757  * The @func pointer points to the worker function. If the @shutdown argument is
758  * not zero, the worker has to free the resources and exit immediately as the
759  * WL sub-system is shutting down.
760  * The worker has to return zero in case of success and a negative error code in
761  * case of failure.
762  */
763 struct ubi_work {
764 	struct list_head list;
765 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
766 	/* The below fields are only relevant to erasure works */
767 	struct ubi_wl_entry *e;
768 	int vol_id;
769 	int lnum;
770 	int torture;
771 	int anchor;
772 };
773 
774 #include "debug.h"
775 
776 extern struct kmem_cache *ubi_wl_entry_slab;
777 extern const struct file_operations ubi_ctrl_cdev_operations;
778 extern const struct file_operations ubi_cdev_operations;
779 extern const struct file_operations ubi_vol_cdev_operations;
780 extern struct class ubi_class;
781 extern struct mutex ubi_devices_mutex;
782 extern struct blocking_notifier_head ubi_notifiers;
783 
784 /* attach.c */
785 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
786 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
787 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
788 				    int vol_id);
789 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
790 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
791 				       struct ubi_attach_info *ai);
792 int ubi_attach(struct ubi_device *ubi, int force_scan);
793 void ubi_destroy_ai(struct ubi_attach_info *ai);
794 
795 /* vtbl.c */
796 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
797 			   struct ubi_vtbl_record *vtbl_rec);
798 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
799 			    struct list_head *rename_list);
800 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
801 
802 /* vmt.c */
803 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
804 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
805 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
806 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
807 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
808 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
809 
810 /* upd.c */
811 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
812 		     long long bytes);
813 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
814 			 const void __user *buf, int count);
815 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
816 			 const struct ubi_leb_change_req *req);
817 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
818 			     const void __user *buf, int count);
819 
820 /* misc.c */
821 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
822 		      int length);
823 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
824 void ubi_update_reserved(struct ubi_device *ubi);
825 void ubi_calculate_reserved(struct ubi_device *ubi);
826 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
827 
828 /* gluebi.c */
829 #ifdef CONFIG_MTD_UBI_GLUEBI
830 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
831 int ubi_destroy_gluebi(struct ubi_volume *vol);
832 void ubi_gluebi_updated(struct ubi_volume *vol);
833 #else
834 #define ubi_create_gluebi(ubi, vol) 0
835 
836 static inline int ubi_destroy_gluebi(struct ubi_volume *vol)
837 {
838 	return 0;
839 }
840 
841 #define ubi_gluebi_updated(vol)
842 #endif
843 
844 /* eba.c */
845 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
846 		      int lnum);
847 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
848 		     void *buf, int offset, int len, int check);
849 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
850 			struct ubi_sgl *sgl, int lnum, int offset, int len,
851 			int check);
852 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
853 		      const void *buf, int offset, int len);
854 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
855 			 int lnum, const void *buf, int len, int used_ebs);
856 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
857 			      int lnum, const void *buf, int len);
858 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
859 		     struct ubi_vid_hdr *vid_hdr);
860 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
861 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
862 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
863 		   struct ubi_attach_info *ai_scan);
864 
865 /* wl.c */
866 int ubi_wl_get_peb(struct ubi_device *ubi);
867 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
868 		   int pnum, int torture);
869 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
870 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
871 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
872 void ubi_wl_close(struct ubi_device *ubi);
873 int ubi_thread(void *u);
874 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
875 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
876 		      int lnum, int torture);
877 int ubi_is_erase_work(struct ubi_work *wrk);
878 void ubi_refill_pools(struct ubi_device *ubi);
879 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
880 
881 /* io.c */
882 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
883 		int len);
884 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
885 		 int len);
886 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
887 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
888 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
889 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
890 		       struct ubi_ec_hdr *ec_hdr, int verbose);
891 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
892 			struct ubi_ec_hdr *ec_hdr);
893 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
894 			struct ubi_vid_hdr *vid_hdr, int verbose);
895 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
896 			 struct ubi_vid_hdr *vid_hdr);
897 
898 /* build.c */
899 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
900 		       int vid_hdr_offset, int max_beb_per1024);
901 int ubi_detach_mtd_dev(int ubi_num, int anyway);
902 struct ubi_device *ubi_get_device(int ubi_num);
903 void ubi_put_device(struct ubi_device *ubi);
904 struct ubi_device *ubi_get_by_major(int major);
905 int ubi_major2num(int major);
906 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
907 		      int ntype);
908 int ubi_notify_all(struct ubi_device *ubi, int ntype,
909 		   struct notifier_block *nb);
910 int ubi_enumerate_volumes(struct notifier_block *nb);
911 void ubi_free_internal_volumes(struct ubi_device *ubi);
912 
913 /* kapi.c */
914 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
915 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
916 			    struct ubi_volume_info *vi);
917 /* scan.c */
918 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
919 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
920 
921 /* fastmap.c */
922 #ifdef CONFIG_MTD_UBI_FASTMAP
923 size_t ubi_calc_fm_size(struct ubi_device *ubi);
924 int ubi_update_fastmap(struct ubi_device *ubi);
925 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
926 		     int fm_anchor);
927 #else
928 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
929 #endif
930 
931 /* block.c */
932 #ifdef CONFIG_MTD_UBI_BLOCK
933 int ubiblock_init(void);
934 void ubiblock_exit(void);
935 int ubiblock_create(struct ubi_volume_info *vi);
936 int ubiblock_remove(struct ubi_volume_info *vi);
937 #else
938 static inline int ubiblock_init(void) { return 0; }
939 static inline void ubiblock_exit(void) {}
940 static inline int ubiblock_create(struct ubi_volume_info *vi)
941 {
942 	return -ENOSYS;
943 }
944 static inline int ubiblock_remove(struct ubi_volume_info *vi)
945 {
946 	return -ENOSYS;
947 }
948 #endif
949 
950 /*
951  * ubi_for_each_free_peb - walk the UBI free 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_free_peb(ubi, e, tmp_rb)	\
957 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
958 
959 /*
960  * ubi_for_each_used_peb - walk the UBI used RB tree.
961  * @ubi: UBI device description object
962  * @e: a pointer to a ubi_wl_entry to use as cursor
963  * @pos: a pointer to RB-tree entry type to use as a loop counter
964  */
965 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
966 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
967 
968 /*
969  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
970  * @ubi: UBI device description object
971  * @e: a pointer to a ubi_wl_entry to use as cursor
972  * @pos: a pointer to RB-tree entry type to use as a loop counter
973  */
974 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
975 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
976 
977 /*
978  * ubi_for_each_protected_peb - walk the UBI protection queue.
979  * @ubi: UBI device description object
980  * @i: a integer used as counter
981  * @e: a pointer to a ubi_wl_entry to use as cursor
982  */
983 #define ubi_for_each_protected_peb(ubi, i, e)	\
984 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
985 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
986 
987 /*
988  * ubi_rb_for_each_entry - walk an RB-tree.
989  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
990  * @pos: a pointer to RB-tree entry type to use as a loop counter
991  * @root: RB-tree's root
992  * @member: the name of the 'struct rb_node' within the RB-tree entry
993  */
994 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
995 	for (rb = rb_first(root),                                            \
996 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
997 	     rb;                                                             \
998 	     rb = rb_next(rb),                                               \
999 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
1000 
1001 /*
1002  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
1003  *
1004  * @av: volume attaching information
1005  * @aeb: attaching eraseblock information
1006  * @list: the list to move to
1007  */
1008 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
1009 					 struct ubi_ainf_peb *aeb,
1010 					 struct list_head *list)
1011 {
1012 		rb_erase(&aeb->u.rb, &av->root);
1013 		list_add_tail(&aeb->u.list, list);
1014 }
1015 
1016 /**
1017  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
1018  * @ubi: UBI device description object
1019  * @gfp_flags: GFP flags to allocate with
1020  *
1021  * This function returns a pointer to the newly allocated and zero-filled
1022  * volume identifier header object in case of success and %NULL in case of
1023  * failure.
1024  */
1025 static inline struct ubi_vid_hdr *
1026 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
1027 {
1028 	void *vid_hdr;
1029 
1030 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
1031 	if (!vid_hdr)
1032 		return NULL;
1033 
1034 	/*
1035 	 * VID headers may be stored at un-aligned flash offsets, so we shift
1036 	 * the pointer.
1037 	 */
1038 	return vid_hdr + ubi->vid_hdr_shift;
1039 }
1040 
1041 /**
1042  * ubi_free_vid_hdr - free a volume identifier header object.
1043  * @ubi: UBI device description object
1044  * @vid_hdr: the object to free
1045  */
1046 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
1047 				    struct ubi_vid_hdr *vid_hdr)
1048 {
1049 	void *p = vid_hdr;
1050 
1051 	if (!p)
1052 		return;
1053 
1054 	kfree(p - ubi->vid_hdr_shift);
1055 }
1056 
1057 /*
1058  * This function is equivalent to 'ubi_io_read()', 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_read_data(const struct ubi_device *ubi, void *buf,
1063 				   int pnum, int offset, int len)
1064 {
1065 	ubi_assert(offset >= 0);
1066 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1067 }
1068 
1069 /*
1070  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1071  * the beginning of the logical eraseblock, not to the beginning of the
1072  * physical eraseblock.
1073  */
1074 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1075 				    int pnum, int offset, int len)
1076 {
1077 	ubi_assert(offset >= 0);
1078 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1079 }
1080 
1081 /**
1082  * ubi_ro_mode - switch to read-only mode.
1083  * @ubi: UBI device description object
1084  */
1085 static inline void ubi_ro_mode(struct ubi_device *ubi)
1086 {
1087 	if (!ubi->ro_mode) {
1088 		ubi->ro_mode = 1;
1089 		ubi_warn(ubi, "switch to read-only mode");
1090 		dump_stack();
1091 	}
1092 }
1093 
1094 /**
1095  * vol_id2idx - get table index by volume ID.
1096  * @ubi: UBI device description object
1097  * @vol_id: volume ID
1098  */
1099 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1100 {
1101 	if (vol_id >= UBI_INTERNAL_VOL_START)
1102 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1103 	else
1104 		return vol_id;
1105 }
1106 
1107 /**
1108  * idx2vol_id - get volume ID by table index.
1109  * @ubi: UBI device description object
1110  * @idx: table index
1111  */
1112 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1113 {
1114 	if (idx >= ubi->vtbl_slots)
1115 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1116 	else
1117 		return idx;
1118 }
1119 
1120 #ifdef __UBOOT__
1121 void ubi_do_worker(struct ubi_device *ubi);
1122 #endif
1123 #endif /* !__UBI_UBI_H__ */
1124