xref: /openbmc/u-boot/drivers/mtd/ubi/ubi.h (revision ba10b852)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2006, 2007
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  *
7  * Author: Artem Bityutskiy (Битюцкий Артём)
8  */
9 
10 #ifndef __UBI_UBI_H__
11 #define __UBI_UBI_H__
12 
13 #ifndef __UBOOT__
14 #include <linux/types.h>
15 #include <linux/list.h>
16 #include <linux/rbtree.h>
17 #include <linux/sched.h>
18 #include <linux/wait.h>
19 #include <linux/mutex.h>
20 #include <linux/rwsem.h>
21 #include <linux/spinlock.h>
22 #include <linux/fs.h>
23 #include <linux/cdev.h>
24 #include <linux/device.h>
25 #include <linux/slab.h>
26 #include <linux/string.h>
27 #include <linux/vmalloc.h>
28 #include <linux/notifier.h>
29 #include <asm/pgtable.h>
30 #else
31 #include <ubi_uboot.h>
32 #endif
33 #include <linux/mtd/mtd.h>
34 #include <linux/mtd/ubi.h>
35 #include "ubi-media.h"
36 #include <mtd/ubi-user.h>
37 
38 /* Maximum number of supported UBI devices */
39 #define UBI_MAX_DEVICES 32
40 
41 /* UBI name used for character devices, sysfs, etc */
42 #define UBI_NAME_STR "ubi"
43 
44 /* Normal UBI messages */
45 #ifdef CONFIG_UBI_SILENCE_MSG
46 #define ubi_msg(ubi, fmt, ...)
47 #else
48 #define ubi_msg(ubi, fmt, ...) printk(UBI_NAME_STR "%d: " fmt "\n", \
49 					 ubi->ubi_num, ##__VA_ARGS__)
50 #endif
51 
52 /* UBI warning messages */
53 #define ubi_warn(ubi, fmt, ...) pr_warn(UBI_NAME_STR "%d warning: %s: " fmt "\n", \
54 					ubi->ubi_num, __func__, ##__VA_ARGS__)
55 /* UBI error messages */
56 #define ubi_err(ubi, fmt, ...) pr_err(UBI_NAME_STR "%d error: %s: " fmt "\n", \
57 				      ubi->ubi_num, __func__, ##__VA_ARGS__)
58 
59 /* Background thread name pattern */
60 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
61 
62 /*
63  * This marker in the EBA table means that the LEB is um-mapped.
64  * NOTE! It has to have the same value as %UBI_ALL.
65  */
66 #define UBI_LEB_UNMAPPED -1
67 
68 /*
69  * In case of errors, UBI tries to repeat the operation several times before
70  * returning error. The below constant defines how many times UBI re-tries.
71  */
72 #define UBI_IO_RETRIES 3
73 
74 /*
75  * Length of the protection queue. The length is effectively equivalent to the
76  * number of (global) erase cycles PEBs are protected from the wear-leveling
77  * worker.
78  */
79 #define UBI_PROT_QUEUE_LEN 10
80 
81 /* The volume ID/LEB number/erase counter is unknown */
82 #define UBI_UNKNOWN -1
83 
84 /*
85  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
86  * + 2 for the number plus 1 for the trailing zero byte.
87  */
88 #define UBI_DFS_DIR_NAME "ubi%d"
89 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
90 
91 /*
92  * Error codes returned by the I/O sub-system.
93  *
94  * UBI_IO_FF: the read region of flash contains only 0xFFs
95  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
96  *                     integrity error reported by the MTD driver
97  *                     (uncorrectable ECC error in case of NAND)
98  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
99  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
100  *                         data integrity error reported by the MTD driver
101  *                         (uncorrectable ECC error in case of NAND)
102  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
103  *
104  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
105  * be or'ed with other error code. But this is a big change because there are
106  * may callers, so it does not worth the risk of introducing a bug
107  */
108 enum {
109 	UBI_IO_FF = 1,
110 	UBI_IO_FF_BITFLIPS,
111 	UBI_IO_BAD_HDR,
112 	UBI_IO_BAD_HDR_EBADMSG,
113 	UBI_IO_BITFLIPS,
114 };
115 
116 /*
117  * Return codes of the 'ubi_eba_copy_leb()' function.
118  *
119  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
120  *                   PEB was put meanwhile, or there is I/O on the source PEB
121  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
122  *                     PEB
123  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
124  *                     PEB
125  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
126  *                     PEB
127  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
128  *                       target PEB
129  * MOVE_RETRY: retry scrubbing the PEB
130  */
131 enum {
132 	MOVE_CANCEL_RACE = 1,
133 	MOVE_SOURCE_RD_ERR,
134 	MOVE_TARGET_RD_ERR,
135 	MOVE_TARGET_WR_ERR,
136 	MOVE_TARGET_BITFLIPS,
137 	MOVE_RETRY,
138 };
139 
140 /*
141  * Return codes of the fastmap sub-system
142  *
143  * UBI_NO_FASTMAP: No fastmap super block was found
144  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
145  */
146 enum {
147 	UBI_NO_FASTMAP = 1,
148 	UBI_BAD_FASTMAP,
149 };
150 
151 /*
152  * Flags for emulate_power_cut in ubi_debug_info
153  *
154  * POWER_CUT_EC_WRITE: Emulate a power cut when writing an EC header
155  * POWER_CUT_VID_WRITE: Emulate a power cut when writing a VID header
156  */
157 enum {
158 	POWER_CUT_EC_WRITE = 0x01,
159 	POWER_CUT_VID_WRITE = 0x02,
160 };
161 
162 /**
163  * struct ubi_wl_entry - wear-leveling entry.
164  * @u.rb: link in the corresponding (free/used) RB-tree
165  * @u.list: link in the protection queue
166  * @ec: erase counter
167  * @pnum: physical eraseblock number
168  *
169  * This data structure is used in the WL sub-system. Each physical eraseblock
170  * has a corresponding &struct wl_entry object which may be kept in different
171  * RB-trees. See WL sub-system for details.
172  */
173 struct ubi_wl_entry {
174 	union {
175 		struct rb_node rb;
176 		struct list_head list;
177 	} u;
178 	int ec;
179 	int pnum;
180 };
181 
182 /**
183  * struct ubi_ltree_entry - an entry in the lock tree.
184  * @rb: links RB-tree nodes
185  * @vol_id: volume ID of the locked logical eraseblock
186  * @lnum: locked logical eraseblock number
187  * @users: how many tasks are using this logical eraseblock or wait for it
188  * @mutex: read/write mutex to implement read/write access serialization to
189  *         the (@vol_id, @lnum) logical eraseblock
190  *
191  * This data structure is used in the EBA sub-system to implement per-LEB
192  * locking. When a logical eraseblock is being locked - corresponding
193  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
194  * See EBA sub-system for details.
195  */
196 struct ubi_ltree_entry {
197 	struct rb_node rb;
198 	int vol_id;
199 	int lnum;
200 	int users;
201 	struct rw_semaphore mutex;
202 };
203 
204 /**
205  * struct ubi_rename_entry - volume re-name description data structure.
206  * @new_name_len: new volume name length
207  * @new_name: new volume name
208  * @remove: if not zero, this volume should be removed, not re-named
209  * @desc: descriptor of the volume
210  * @list: links re-name entries into a list
211  *
212  * This data structure is utilized in the multiple volume re-name code. Namely,
213  * UBI first creates a list of &struct ubi_rename_entry objects from the
214  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
215  * the job.
216  */
217 struct ubi_rename_entry {
218 	int new_name_len;
219 	char new_name[UBI_VOL_NAME_MAX + 1];
220 	int remove;
221 	struct ubi_volume_desc *desc;
222 	struct list_head list;
223 };
224 
225 struct ubi_volume_desc;
226 
227 /**
228  * struct ubi_fastmap_layout - in-memory fastmap data structure.
229  * @e: PEBs used by the current fastmap
230  * @to_be_tortured: if non-zero tortured this PEB
231  * @used_blocks: number of used PEBs
232  * @max_pool_size: maximal size of the user pool
233  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
234  */
235 struct ubi_fastmap_layout {
236 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
237 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
238 	int used_blocks;
239 	int max_pool_size;
240 	int max_wl_pool_size;
241 };
242 
243 /**
244  * struct ubi_fm_pool - in-memory fastmap pool
245  * @pebs: PEBs in this pool
246  * @used: number of used PEBs
247  * @size: total number of PEBs in this pool
248  * @max_size: maximal size of the pool
249  *
250  * A pool gets filled with up to max_size.
251  * If all PEBs within the pool are used a new fastmap will be written
252  * to the flash and the pool gets refilled with empty PEBs.
253  *
254  */
255 struct ubi_fm_pool {
256 	int pebs[UBI_FM_MAX_POOL_SIZE];
257 	int used;
258 	int size;
259 	int max_size;
260 };
261 
262 /**
263  * struct ubi_volume - UBI volume description data structure.
264  * @dev: device object to make use of the the Linux device model
265  * @cdev: character device object to create character device
266  * @ubi: reference to the UBI device description object
267  * @vol_id: volume ID
268  * @ref_count: volume reference count
269  * @readers: number of users holding this volume in read-only mode
270  * @writers: number of users holding this volume in read-write mode
271  * @exclusive: whether somebody holds this volume in exclusive mode
272  * @metaonly: whether somebody is altering only meta data of this volume
273  *
274  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
275  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
276  * @usable_leb_size: logical eraseblock size without padding
277  * @used_ebs: how many logical eraseblocks in this volume contain data
278  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
279  * @used_bytes: how many bytes of data this volume contains
280  * @alignment: volume alignment
281  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
282  *            satisfy the requested alignment
283  * @name_len: volume name length
284  * @name: volume name
285  *
286  * @upd_ebs: how many eraseblocks are expected to be updated
287  * @ch_lnum: LEB number which is being changing by the atomic LEB change
288  *           operation
289  * @upd_bytes: how many bytes are expected to be received for volume update or
290  *             atomic LEB change
291  * @upd_received: how many bytes were already received for volume update or
292  *                atomic LEB change
293  * @upd_buf: update buffer which is used to collect update data or data for
294  *           atomic LEB change
295  *
296  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
297  * @checked: %1 if this static volume was checked
298  * @corrupted: %1 if the volume is corrupted (static volumes only)
299  * @upd_marker: %1 if the update marker is set for this volume
300  * @updating: %1 if the volume is being updated
301  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
302  * @direct_writes: %1 if direct writes are enabled for this volume
303  *
304  * The @corrupted field indicates that the volume's contents is corrupted.
305  * Since UBI protects only static volumes, this field is not relevant to
306  * dynamic volumes - it is user's responsibility to assure their data
307  * integrity.
308  *
309  * The @upd_marker flag indicates that this volume is either being updated at
310  * the moment or is damaged because of an unclean reboot.
311  */
312 struct ubi_volume {
313 	struct device dev;
314 	struct cdev cdev;
315 	struct ubi_device *ubi;
316 	int vol_id;
317 	int ref_count;
318 	int readers;
319 	int writers;
320 	int exclusive;
321 	int metaonly;
322 
323 	int reserved_pebs;
324 	int vol_type;
325 	int usable_leb_size;
326 	int used_ebs;
327 #ifndef __UBOOT__
328 	int last_eb_bytes;
329 #else
330 	u32 last_eb_bytes;
331 #endif
332 	long long used_bytes;
333 	int alignment;
334 	int data_pad;
335 	int name_len;
336 	char name[UBI_VOL_NAME_MAX + 1];
337 
338 	int upd_ebs;
339 	int ch_lnum;
340 	long long upd_bytes;
341 	long long upd_received;
342 	void *upd_buf;
343 
344 	int *eba_tbl;
345 	unsigned int checked:1;
346 	unsigned int corrupted:1;
347 	unsigned int upd_marker:1;
348 	unsigned int updating:1;
349 	unsigned int changing_leb:1;
350 	unsigned int direct_writes:1;
351 };
352 
353 /**
354  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
355  * @vol: reference to the corresponding volume description object
356  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, %UBI_EXCLUSIVE
357  * or %UBI_METAONLY)
358  */
359 struct ubi_volume_desc {
360 	struct ubi_volume *vol;
361 	int mode;
362 };
363 
364 struct ubi_wl_entry;
365 
366 /**
367  * struct ubi_debug_info - debugging information for an UBI device.
368  *
369  * @chk_gen: if UBI general extra checks are enabled
370  * @chk_io: if UBI I/O extra checks are enabled
371  * @chk_fastmap: if UBI fastmap extra checks are enabled
372  * @disable_bgt: disable the background task for testing purposes
373  * @emulate_bitflips: emulate bit-flips for testing purposes
374  * @emulate_io_failures: emulate write/erase failures for testing purposes
375  * @emulate_power_cut: emulate power cut for testing purposes
376  * @power_cut_counter: count down for writes left until emulated power cut
377  * @power_cut_min: minimum number of writes before emulating a power cut
378  * @power_cut_max: maximum number of writes until emulating a power cut
379  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
380  * @dfs_dir: direntry object of the UBI device debugfs directory
381  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
382  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
383  * @dfs_chk_fastmap: debugfs knob to enable UBI fastmap extra checks
384  * @dfs_disable_bgt: debugfs knob to disable the background task
385  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
386  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
387  * @dfs_emulate_power_cut: debugfs knob to emulate power cuts
388  * @dfs_power_cut_min: debugfs knob for minimum writes before power cut
389  * @dfs_power_cut_max: debugfs knob for maximum writes until power cut
390  */
391 struct ubi_debug_info {
392 	unsigned int chk_gen:1;
393 	unsigned int chk_io:1;
394 	unsigned int chk_fastmap:1;
395 	unsigned int disable_bgt:1;
396 	unsigned int emulate_bitflips:1;
397 	unsigned int emulate_io_failures:1;
398 	unsigned int emulate_power_cut:2;
399 	unsigned int power_cut_counter;
400 	unsigned int power_cut_min;
401 	unsigned int power_cut_max;
402 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
403 	struct dentry *dfs_dir;
404 	struct dentry *dfs_chk_gen;
405 	struct dentry *dfs_chk_io;
406 	struct dentry *dfs_chk_fastmap;
407 	struct dentry *dfs_disable_bgt;
408 	struct dentry *dfs_emulate_bitflips;
409 	struct dentry *dfs_emulate_io_failures;
410 	struct dentry *dfs_emulate_power_cut;
411 	struct dentry *dfs_power_cut_min;
412 	struct dentry *dfs_power_cut_max;
413 };
414 
415 /**
416  * struct ubi_device - UBI device description structure
417  * @dev: UBI device object to use the the Linux device model
418  * @cdev: character device object to create character device
419  * @ubi_num: UBI device number
420  * @ubi_name: UBI device name
421  * @vol_count: number of volumes in this UBI device
422  * @volumes: volumes of this UBI device
423  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
424  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
425  *                @vol->readers, @vol->writers, @vol->exclusive,
426  *                @vol->metaonly, @vol->ref_count, @vol->mapping and
427  *                @vol->eba_tbl.
428  * @ref_count: count of references on the UBI device
429  * @image_seq: image sequence number recorded on EC headers
430  *
431  * @rsvd_pebs: count of reserved physical eraseblocks
432  * @avail_pebs: count of available physical eraseblocks
433  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
434  *                 handling
435  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
436  *
437  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
438  *                     of UBI initialization
439  * @vtbl_slots: how many slots are available in the volume table
440  * @vtbl_size: size of the volume table in bytes
441  * @vtbl: in-RAM volume table copy
442  * @device_mutex: protects on-flash volume table and serializes volume
443  *                creation, deletion, update, re-size, re-name and set
444  *                property
445  *
446  * @max_ec: current highest erase counter value
447  * @mean_ec: current mean erase counter value
448  *
449  * @global_sqnum: global sequence number
450  * @ltree_lock: protects the lock tree and @global_sqnum
451  * @ltree: the lock tree
452  * @alc_mutex: serializes "atomic LEB change" operations
453  *
454  * @fm_disabled: non-zero if fastmap is disabled (default)
455  * @fm: in-memory data structure of the currently used fastmap
456  * @fm_pool: in-memory data structure of the fastmap pool
457  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
458  *		sub-system
459  * @fm_protect: serializes ubi_update_fastmap(), protects @fm_buf and makes sure
460  * that critical sections cannot be interrupted by ubi_update_fastmap()
461  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
462  * @fm_size: fastmap size in bytes
463  * @fm_eba_sem: allows ubi_update_fastmap() to block EBA table changes
464  * @fm_work: fastmap work queue
465  * @fm_work_scheduled: non-zero if fastmap work was scheduled
466  *
467  * @used: RB-tree of used physical eraseblocks
468  * @erroneous: RB-tree of erroneous used physical eraseblocks
469  * @free: RB-tree of free physical eraseblocks
470  * @free_count: Contains the number of elements in @free
471  * @scrub: RB-tree of physical eraseblocks which need scrubbing
472  * @pq: protection queue (contain physical eraseblocks which are temporarily
473  *      protected from the wear-leveling worker)
474  * @pq_head: protection queue head
475  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
476  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
477  *	     @erroneous, @erroneous_peb_count, @fm_work_scheduled, @fm_pool,
478  *	     and @fm_wl_pool fields
479  * @move_mutex: serializes eraseblock moves
480  * @work_sem: used to wait for all the scheduled works to finish and prevent
481  * new works from being submitted
482  * @wl_scheduled: non-zero if the wear-leveling was scheduled
483  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
484  *             physical eraseblock
485  * @move_from: physical eraseblock from where the data is being moved
486  * @move_to: physical eraseblock where the data is being moved to
487  * @move_to_put: if the "to" PEB was put
488  * @works: list of pending works
489  * @works_count: count of pending works
490  * @bgt_thread: background thread description object
491  * @thread_enabled: if the background thread is enabled
492  * @bgt_name: background thread name
493  *
494  * @flash_size: underlying MTD device size (in bytes)
495  * @peb_count: count of physical eraseblocks on the MTD device
496  * @peb_size: physical eraseblock size
497  * @bad_peb_limit: top limit of expected bad physical eraseblocks
498  * @bad_peb_count: count of bad physical eraseblocks
499  * @good_peb_count: count of good physical eraseblocks
500  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
501  *                  used by UBI)
502  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
503  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
504  * @min_io_size: minimal input/output unit size of the underlying MTD device
505  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
506  * @ro_mode: if the UBI device is in read-only mode
507  * @leb_size: logical eraseblock size
508  * @leb_start: starting offset of logical eraseblocks within physical
509  *             eraseblocks
510  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
511  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
512  * @vid_hdr_offset: starting offset of the volume identifier header (might be
513  *                  unaligned)
514  * @vid_hdr_aloffset: starting offset of the VID header aligned to
515  *                    @hdrs_min_io_size
516  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
517  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
518  *               not
519  * @nor_flash: non-zero if working on top of NOR flash
520  * @max_write_size: maximum amount of bytes the underlying flash can write at a
521  *                  time (MTD write buffer size)
522  * @mtd: MTD device descriptor
523  *
524  * @peb_buf: a buffer of PEB size used for different purposes
525  * @buf_mutex: protects @peb_buf
526  * @ckvol_mutex: serializes static volume checking when opening
527  *
528  * @dbg: debugging information for this UBI device
529  */
530 struct ubi_device {
531 	struct cdev cdev;
532 	struct device dev;
533 	int ubi_num;
534 	char ubi_name[sizeof(UBI_NAME_STR)+5];
535 	int vol_count;
536 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
537 	spinlock_t volumes_lock;
538 	int ref_count;
539 	int image_seq;
540 
541 	int rsvd_pebs;
542 	int avail_pebs;
543 	int beb_rsvd_pebs;
544 	int beb_rsvd_level;
545 	int bad_peb_limit;
546 
547 	int autoresize_vol_id;
548 	int vtbl_slots;
549 	int vtbl_size;
550 	struct ubi_vtbl_record *vtbl;
551 	struct mutex device_mutex;
552 
553 	int max_ec;
554 	/* Note, mean_ec is not updated run-time - should be fixed */
555 	int mean_ec;
556 
557 	/* EBA sub-system's stuff */
558 	unsigned long long global_sqnum;
559 	spinlock_t ltree_lock;
560 	struct rb_root ltree;
561 	struct mutex alc_mutex;
562 
563 	/* Fastmap stuff */
564 	int fm_disabled;
565 	struct ubi_fastmap_layout *fm;
566 	struct ubi_fm_pool fm_pool;
567 	struct ubi_fm_pool fm_wl_pool;
568 	struct rw_semaphore fm_eba_sem;
569 	struct rw_semaphore fm_protect;
570 	void *fm_buf;
571 	size_t fm_size;
572 #ifndef __UBOOT__
573 	struct work_struct fm_work;
574 #endif
575 	int fm_work_scheduled;
576 
577 	/* Wear-leveling sub-system's stuff */
578 	struct rb_root used;
579 	struct rb_root erroneous;
580 	struct rb_root free;
581 	int free_count;
582 	struct rb_root scrub;
583 	struct list_head pq[UBI_PROT_QUEUE_LEN];
584 	int pq_head;
585 	spinlock_t wl_lock;
586 	struct mutex move_mutex;
587 	struct rw_semaphore work_sem;
588 	int wl_scheduled;
589 	struct ubi_wl_entry **lookuptbl;
590 	struct ubi_wl_entry *move_from;
591 	struct ubi_wl_entry *move_to;
592 	int move_to_put;
593 	struct list_head works;
594 	int works_count;
595 	struct task_struct *bgt_thread;
596 	int thread_enabled;
597 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
598 
599 	/* I/O sub-system's stuff */
600 	long long flash_size;
601 	int peb_count;
602 	int peb_size;
603 	int bad_peb_count;
604 	int good_peb_count;
605 	int corr_peb_count;
606 	int erroneous_peb_count;
607 	int max_erroneous;
608 	int min_io_size;
609 	int hdrs_min_io_size;
610 	int ro_mode;
611 	int leb_size;
612 	int leb_start;
613 	int ec_hdr_alsize;
614 	int vid_hdr_alsize;
615 	int vid_hdr_offset;
616 	int vid_hdr_aloffset;
617 	int vid_hdr_shift;
618 	unsigned int bad_allowed:1;
619 	unsigned int nor_flash:1;
620 	int max_write_size;
621 	struct mtd_info *mtd;
622 
623 	void *peb_buf;
624 	struct mutex buf_mutex;
625 	struct mutex ckvol_mutex;
626 
627 	struct ubi_debug_info dbg;
628 };
629 
630 /**
631  * struct ubi_ainf_peb - attach information about a physical eraseblock.
632  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
633  * @pnum: physical eraseblock number
634  * @vol_id: ID of the volume this LEB belongs to
635  * @lnum: logical eraseblock number
636  * @scrub: if this physical eraseblock needs scrubbing
637  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
638  * @sqnum: sequence number
639  * @u: unions RB-tree or @list links
640  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
641  * @u.list: link in one of the eraseblock lists
642  *
643  * One object of this type is allocated for each physical eraseblock when
644  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
645  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
646  */
647 struct ubi_ainf_peb {
648 	int ec;
649 	int pnum;
650 	int vol_id;
651 	int lnum;
652 	unsigned int scrub:1;
653 	unsigned int copy_flag:1;
654 	unsigned long long sqnum;
655 	union {
656 		struct rb_node rb;
657 		struct list_head list;
658 	} u;
659 };
660 
661 /**
662  * struct ubi_ainf_volume - attaching information about a volume.
663  * @vol_id: volume ID
664  * @highest_lnum: highest logical eraseblock number in this volume
665  * @leb_count: number of logical eraseblocks in this volume
666  * @vol_type: volume type
667  * @used_ebs: number of used logical eraseblocks in this volume (only for
668  *            static volumes)
669  * @last_data_size: amount of data in the last logical eraseblock of this
670  *                  volume (always equivalent to the usable logical eraseblock
671  *                  size in case of dynamic volumes)
672  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
673  *            are not used (due to volume alignment)
674  * @compat: compatibility flags of this volume
675  * @rb: link in the volume RB-tree
676  * @root: root of the RB-tree containing all the eraseblock belonging to this
677  *        volume (&struct ubi_ainf_peb objects)
678  *
679  * One object of this type is allocated for each volume when attaching an MTD
680  * device.
681  */
682 struct ubi_ainf_volume {
683 	int vol_id;
684 	int highest_lnum;
685 	int leb_count;
686 	int vol_type;
687 	int used_ebs;
688 	int last_data_size;
689 	int data_pad;
690 	int compat;
691 	struct rb_node rb;
692 	struct rb_root root;
693 };
694 
695 /**
696  * struct ubi_attach_info - MTD device attaching information.
697  * @volumes: root of the volume RB-tree
698  * @corr: list of corrupted physical eraseblocks
699  * @free: list of free physical eraseblocks
700  * @erase: list of physical eraseblocks which have to be erased
701  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
702  *         those belonging to "preserve"-compatible internal volumes)
703  * @corr_peb_count: count of PEBs in the @corr list
704  * @empty_peb_count: count of PEBs which are presumably empty (contain only
705  *                   0xFF bytes)
706  * @alien_peb_count: count of PEBs in the @alien list
707  * @bad_peb_count: count of bad physical eraseblocks
708  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
709  *                       as bad yet, but which look like bad
710  * @vols_found: number of volumes found
711  * @highest_vol_id: highest volume ID
712  * @is_empty: flag indicating whether the MTD device is empty or not
713  * @min_ec: lowest erase counter value
714  * @max_ec: highest erase counter value
715  * @max_sqnum: highest sequence number value
716  * @mean_ec: mean erase counter value
717  * @ec_sum: a temporary variable used when calculating @mean_ec
718  * @ec_count: a temporary variable used when calculating @mean_ec
719  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
720  *
721  * This data structure contains the result of attaching an MTD device and may
722  * be used by other UBI sub-systems to build final UBI data structures, further
723  * error-recovery and so on.
724  */
725 struct ubi_attach_info {
726 	struct rb_root volumes;
727 	struct list_head corr;
728 	struct list_head free;
729 	struct list_head erase;
730 	struct list_head alien;
731 	int corr_peb_count;
732 	int empty_peb_count;
733 	int alien_peb_count;
734 	int bad_peb_count;
735 	int maybe_bad_peb_count;
736 	int vols_found;
737 	int highest_vol_id;
738 	int is_empty;
739 	int min_ec;
740 	int max_ec;
741 	unsigned long long max_sqnum;
742 	int mean_ec;
743 	uint64_t ec_sum;
744 	int ec_count;
745 	struct kmem_cache *aeb_slab_cache;
746 };
747 
748 /**
749  * struct ubi_work - UBI work description data structure.
750  * @list: a link in the list of pending works
751  * @func: worker function
752  * @e: physical eraseblock to erase
753  * @vol_id: the volume ID on which this erasure is being performed
754  * @lnum: the logical eraseblock number
755  * @torture: if the physical eraseblock has to be tortured
756  * @anchor: produce a anchor PEB to by used by fastmap
757  *
758  * The @func pointer points to the worker function. If the @shutdown argument is
759  * not zero, the worker has to free the resources and exit immediately as the
760  * WL sub-system is shutting down.
761  * The worker has to return zero in case of success and a negative error code in
762  * case of failure.
763  */
764 struct ubi_work {
765 	struct list_head list;
766 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
767 	/* The below fields are only relevant to erasure works */
768 	struct ubi_wl_entry *e;
769 	int vol_id;
770 	int lnum;
771 	int torture;
772 	int anchor;
773 };
774 
775 #include "debug.h"
776 
777 extern struct kmem_cache *ubi_wl_entry_slab;
778 extern const struct file_operations ubi_ctrl_cdev_operations;
779 extern const struct file_operations ubi_cdev_operations;
780 extern const struct file_operations ubi_vol_cdev_operations;
781 extern struct class ubi_class;
782 extern struct mutex ubi_devices_mutex;
783 extern struct blocking_notifier_head ubi_notifiers;
784 
785 /* attach.c */
786 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
787 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
788 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
789 				    int vol_id);
790 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
791 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
792 				       struct ubi_attach_info *ai);
793 int ubi_attach(struct ubi_device *ubi, int force_scan);
794 void ubi_destroy_ai(struct ubi_attach_info *ai);
795 
796 /* vtbl.c */
797 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
798 			   struct ubi_vtbl_record *vtbl_rec);
799 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
800 			    struct list_head *rename_list);
801 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
802 
803 /* vmt.c */
804 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
805 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
806 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
807 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
808 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
809 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
810 
811 /* upd.c */
812 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
813 		     long long bytes);
814 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
815 			 const void __user *buf, int count);
816 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
817 			 const struct ubi_leb_change_req *req);
818 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
819 			     const void __user *buf, int count);
820 
821 /* misc.c */
822 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
823 		      int length);
824 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
825 void ubi_update_reserved(struct ubi_device *ubi);
826 void ubi_calculate_reserved(struct ubi_device *ubi);
827 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
828 
829 /* gluebi.c */
830 #ifdef CONFIG_MTD_UBI_GLUEBI
831 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
832 int ubi_destroy_gluebi(struct ubi_volume *vol);
833 void ubi_gluebi_updated(struct ubi_volume *vol);
834 #else
835 #define ubi_create_gluebi(ubi, vol) 0
836 
837 static inline int ubi_destroy_gluebi(struct ubi_volume *vol)
838 {
839 	return 0;
840 }
841 
842 #define ubi_gluebi_updated(vol)
843 #endif
844 
845 /* eba.c */
846 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
847 		      int lnum);
848 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
849 		     void *buf, int offset, int len, int check);
850 int ubi_eba_read_leb_sg(struct ubi_device *ubi, struct ubi_volume *vol,
851 			struct ubi_sgl *sgl, int lnum, int offset, int len,
852 			int check);
853 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
854 		      const void *buf, int offset, int len);
855 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
856 			 int lnum, const void *buf, int len, int used_ebs);
857 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
858 			      int lnum, const void *buf, int len);
859 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
860 		     struct ubi_vid_hdr *vid_hdr);
861 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
862 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
863 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
864 		   struct ubi_attach_info *ai_scan);
865 
866 /* wl.c */
867 int ubi_wl_get_peb(struct ubi_device *ubi);
868 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
869 		   int pnum, int torture);
870 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
871 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
872 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
873 void ubi_wl_close(struct ubi_device *ubi);
874 int ubi_thread(void *u);
875 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
876 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
877 		      int lnum, int torture);
878 int ubi_is_erase_work(struct ubi_work *wrk);
879 void ubi_refill_pools(struct ubi_device *ubi);
880 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
881 
882 /* io.c */
883 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
884 		int len);
885 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
886 		 int len);
887 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
888 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
889 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
890 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
891 		       struct ubi_ec_hdr *ec_hdr, int verbose);
892 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
893 			struct ubi_ec_hdr *ec_hdr);
894 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
895 			struct ubi_vid_hdr *vid_hdr, int verbose);
896 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
897 			 struct ubi_vid_hdr *vid_hdr);
898 
899 /* build.c */
900 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
901 		       int vid_hdr_offset, int max_beb_per1024);
902 int ubi_detach_mtd_dev(int ubi_num, int anyway);
903 struct ubi_device *ubi_get_device(int ubi_num);
904 void ubi_put_device(struct ubi_device *ubi);
905 struct ubi_device *ubi_get_by_major(int major);
906 int ubi_major2num(int major);
907 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
908 		      int ntype);
909 int ubi_notify_all(struct ubi_device *ubi, int ntype,
910 		   struct notifier_block *nb);
911 int ubi_enumerate_volumes(struct notifier_block *nb);
912 void ubi_free_internal_volumes(struct ubi_device *ubi);
913 
914 /* kapi.c */
915 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
916 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
917 			    struct ubi_volume_info *vi);
918 /* scan.c */
919 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
920 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
921 
922 /* fastmap.c */
923 #ifdef CONFIG_MTD_UBI_FASTMAP
924 size_t ubi_calc_fm_size(struct ubi_device *ubi);
925 int ubi_update_fastmap(struct ubi_device *ubi);
926 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
927 		     int fm_anchor);
928 #else
929 static inline int ubi_update_fastmap(struct ubi_device *ubi) { return 0; }
930 #endif
931 
932 /* block.c */
933 #ifdef CONFIG_MTD_UBI_BLOCK
934 int ubiblock_init(void);
935 void ubiblock_exit(void);
936 int ubiblock_create(struct ubi_volume_info *vi);
937 int ubiblock_remove(struct ubi_volume_info *vi);
938 #else
939 static inline int ubiblock_init(void) { return 0; }
940 static inline void ubiblock_exit(void) {}
941 static inline int ubiblock_create(struct ubi_volume_info *vi)
942 {
943 	return -ENOSYS;
944 }
945 static inline int ubiblock_remove(struct ubi_volume_info *vi)
946 {
947 	return -ENOSYS;
948 }
949 #endif
950 
951 /*
952  * ubi_for_each_free_peb - walk the UBI free RB tree.
953  * @ubi: UBI device description object
954  * @e: a pointer to a ubi_wl_entry to use as cursor
955  * @pos: a pointer to RB-tree entry type to use as a loop counter
956  */
957 #define ubi_for_each_free_peb(ubi, e, tmp_rb)	\
958 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->free, u.rb)
959 
960 /*
961  * ubi_for_each_used_peb - walk the UBI used RB tree.
962  * @ubi: UBI device description object
963  * @e: a pointer to a ubi_wl_entry to use as cursor
964  * @pos: a pointer to RB-tree entry type to use as a loop counter
965  */
966 #define ubi_for_each_used_peb(ubi, e, tmp_rb)	\
967 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->used, u.rb)
968 
969 /*
970  * ubi_for_each_scub_peb - walk the UBI scub RB tree.
971  * @ubi: UBI device description object
972  * @e: a pointer to a ubi_wl_entry to use as cursor
973  * @pos: a pointer to RB-tree entry type to use as a loop counter
974  */
975 #define ubi_for_each_scrub_peb(ubi, e, tmp_rb)	\
976 	ubi_rb_for_each_entry((tmp_rb), (e), &(ubi)->scrub, u.rb)
977 
978 /*
979  * ubi_for_each_protected_peb - walk the UBI protection queue.
980  * @ubi: UBI device description object
981  * @i: a integer used as counter
982  * @e: a pointer to a ubi_wl_entry to use as cursor
983  */
984 #define ubi_for_each_protected_peb(ubi, i, e)	\
985 	for ((i) = 0; (i) < UBI_PROT_QUEUE_LEN; (i)++)	\
986 		list_for_each_entry((e), &(ubi->pq[(i)]), u.list)
987 
988 /*
989  * ubi_rb_for_each_entry - walk an RB-tree.
990  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
991  * @pos: a pointer to RB-tree entry type to use as a loop counter
992  * @root: RB-tree's root
993  * @member: the name of the 'struct rb_node' within the RB-tree entry
994  */
995 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
996 	for (rb = rb_first(root),                                            \
997 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
998 	     rb;                                                             \
999 	     rb = rb_next(rb),                                               \
1000 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
1001 
1002 /*
1003  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
1004  *
1005  * @av: volume attaching information
1006  * @aeb: attaching eraseblock information
1007  * @list: the list to move to
1008  */
1009 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
1010 					 struct ubi_ainf_peb *aeb,
1011 					 struct list_head *list)
1012 {
1013 		rb_erase(&aeb->u.rb, &av->root);
1014 		list_add_tail(&aeb->u.list, list);
1015 }
1016 
1017 /**
1018  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
1019  * @ubi: UBI device description object
1020  * @gfp_flags: GFP flags to allocate with
1021  *
1022  * This function returns a pointer to the newly allocated and zero-filled
1023  * volume identifier header object in case of success and %NULL in case of
1024  * failure.
1025  */
1026 static inline struct ubi_vid_hdr *
1027 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
1028 {
1029 	void *vid_hdr;
1030 
1031 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
1032 	if (!vid_hdr)
1033 		return NULL;
1034 
1035 	/*
1036 	 * VID headers may be stored at un-aligned flash offsets, so we shift
1037 	 * the pointer.
1038 	 */
1039 	return vid_hdr + ubi->vid_hdr_shift;
1040 }
1041 
1042 /**
1043  * ubi_free_vid_hdr - free a volume identifier header object.
1044  * @ubi: UBI device description object
1045  * @vid_hdr: the object to free
1046  */
1047 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
1048 				    struct ubi_vid_hdr *vid_hdr)
1049 {
1050 	void *p = vid_hdr;
1051 
1052 	if (!p)
1053 		return;
1054 
1055 	kfree(p - ubi->vid_hdr_shift);
1056 }
1057 
1058 /*
1059  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
1060  * the beginning of the logical eraseblock, not to the beginning of the
1061  * physical eraseblock.
1062  */
1063 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
1064 				   int pnum, int offset, int len)
1065 {
1066 	ubi_assert(offset >= 0);
1067 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
1068 }
1069 
1070 /*
1071  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
1072  * the beginning of the logical eraseblock, not to the beginning of the
1073  * physical eraseblock.
1074  */
1075 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
1076 				    int pnum, int offset, int len)
1077 {
1078 	ubi_assert(offset >= 0);
1079 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
1080 }
1081 
1082 /**
1083  * ubi_ro_mode - switch to read-only mode.
1084  * @ubi: UBI device description object
1085  */
1086 static inline void ubi_ro_mode(struct ubi_device *ubi)
1087 {
1088 	if (!ubi->ro_mode) {
1089 		ubi->ro_mode = 1;
1090 		ubi_warn(ubi, "switch to read-only mode");
1091 		dump_stack();
1092 	}
1093 }
1094 
1095 /**
1096  * vol_id2idx - get table index by volume ID.
1097  * @ubi: UBI device description object
1098  * @vol_id: volume ID
1099  */
1100 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1101 {
1102 	if (vol_id >= UBI_INTERNAL_VOL_START)
1103 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1104 	else
1105 		return vol_id;
1106 }
1107 
1108 /**
1109  * idx2vol_id - get volume ID by table index.
1110  * @ubi: UBI device description object
1111  * @idx: table index
1112  */
1113 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1114 {
1115 	if (idx >= ubi->vtbl_slots)
1116 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1117 	else
1118 		return idx;
1119 }
1120 
1121 #ifdef __UBOOT__
1122 int do_work(struct ubi_device *ubi);
1123 #endif
1124 #endif /* !__UBI_UBI_H__ */
1125