xref: /openbmc/u-boot/drivers/mtd/ubi/ubi.h (revision fea7f3aa)
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(fmt, ...)
47 #else
48 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
49 #endif
50 
51 /* UBI warning messages */
52 #define ubi_warn(fmt, ...) pr_warn("UBI warning: %s: " fmt "\n",  \
53 				   __func__, ##__VA_ARGS__)
54 /* UBI error messages */
55 #define ubi_err(fmt, ...) pr_err("UBI error: %s: " fmt "\n",      \
56 				 __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  * struct ubi_wl_entry - wear-leveling entry.
152  * @u.rb: link in the corresponding (free/used) RB-tree
153  * @u.list: link in the protection queue
154  * @ec: erase counter
155  * @pnum: physical eraseblock number
156  *
157  * This data structure is used in the WL sub-system. Each physical eraseblock
158  * has a corresponding &struct wl_entry object which may be kept in different
159  * RB-trees. See WL sub-system for details.
160  */
161 struct ubi_wl_entry {
162 	union {
163 		struct rb_node rb;
164 		struct list_head list;
165 	} u;
166 	int ec;
167 	int pnum;
168 };
169 
170 /**
171  * struct ubi_ltree_entry - an entry in the lock tree.
172  * @rb: links RB-tree nodes
173  * @vol_id: volume ID of the locked logical eraseblock
174  * @lnum: locked logical eraseblock number
175  * @users: how many tasks are using this logical eraseblock or wait for it
176  * @mutex: read/write mutex to implement read/write access serialization to
177  *         the (@vol_id, @lnum) logical eraseblock
178  *
179  * This data structure is used in the EBA sub-system to implement per-LEB
180  * locking. When a logical eraseblock is being locked - corresponding
181  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
182  * See EBA sub-system for details.
183  */
184 struct ubi_ltree_entry {
185 	struct rb_node rb;
186 	int vol_id;
187 	int lnum;
188 	int users;
189 	struct rw_semaphore mutex;
190 };
191 
192 /**
193  * struct ubi_rename_entry - volume re-name description data structure.
194  * @new_name_len: new volume name length
195  * @new_name: new volume name
196  * @remove: if not zero, this volume should be removed, not re-named
197  * @desc: descriptor of the volume
198  * @list: links re-name entries into a list
199  *
200  * This data structure is utilized in the multiple volume re-name code. Namely,
201  * UBI first creates a list of &struct ubi_rename_entry objects from the
202  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
203  * the job.
204  */
205 struct ubi_rename_entry {
206 	int new_name_len;
207 	char new_name[UBI_VOL_NAME_MAX + 1];
208 	int remove;
209 	struct ubi_volume_desc *desc;
210 	struct list_head list;
211 };
212 
213 struct ubi_volume_desc;
214 
215 /**
216  * struct ubi_fastmap_layout - in-memory fastmap data structure.
217  * @e: PEBs used by the current fastmap
218  * @to_be_tortured: if non-zero tortured this PEB
219  * @used_blocks: number of used PEBs
220  * @max_pool_size: maximal size of the user pool
221  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
222  */
223 struct ubi_fastmap_layout {
224 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
225 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
226 	int used_blocks;
227 	int max_pool_size;
228 	int max_wl_pool_size;
229 };
230 
231 /**
232  * struct ubi_fm_pool - in-memory fastmap pool
233  * @pebs: PEBs in this pool
234  * @used: number of used PEBs
235  * @size: total number of PEBs in this pool
236  * @max_size: maximal size of the pool
237  *
238  * A pool gets filled with up to max_size.
239  * If all PEBs within the pool are used a new fastmap will be written
240  * to the flash and the pool gets refilled with empty PEBs.
241  *
242  */
243 struct ubi_fm_pool {
244 	int pebs[UBI_FM_MAX_POOL_SIZE];
245 	int used;
246 	int size;
247 	int max_size;
248 };
249 
250 /**
251  * struct ubi_volume - UBI volume description data structure.
252  * @dev: device object to make use of the the Linux device model
253  * @cdev: character device object to create character device
254  * @ubi: reference to the UBI device description object
255  * @vol_id: volume ID
256  * @ref_count: volume reference count
257  * @readers: number of users holding this volume in read-only mode
258  * @writers: number of users holding this volume in read-write mode
259  * @exclusive: whether somebody holds this volume in exclusive mode
260  *
261  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
262  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
263  * @usable_leb_size: logical eraseblock size without padding
264  * @used_ebs: how many logical eraseblocks in this volume contain data
265  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
266  * @used_bytes: how many bytes of data this volume contains
267  * @alignment: volume alignment
268  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
269  *            satisfy the requested alignment
270  * @name_len: volume name length
271  * @name: volume name
272  *
273  * @upd_ebs: how many eraseblocks are expected to be updated
274  * @ch_lnum: LEB number which is being changing by the atomic LEB change
275  *           operation
276  * @upd_bytes: how many bytes are expected to be received for volume update or
277  *             atomic LEB change
278  * @upd_received: how many bytes were already received for volume update or
279  *                atomic LEB change
280  * @upd_buf: update buffer which is used to collect update data or data for
281  *           atomic LEB change
282  *
283  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
284  * @checked: %1 if this static volume was checked
285  * @corrupted: %1 if the volume is corrupted (static volumes only)
286  * @upd_marker: %1 if the update marker is set for this volume
287  * @updating: %1 if the volume is being updated
288  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
289  * @direct_writes: %1 if direct writes are enabled for this volume
290  *
291  * The @corrupted field indicates that the volume's contents is corrupted.
292  * Since UBI protects only static volumes, this field is not relevant to
293  * dynamic volumes - it is user's responsibility to assure their data
294  * integrity.
295  *
296  * The @upd_marker flag indicates that this volume is either being updated at
297  * the moment or is damaged because of an unclean reboot.
298  */
299 struct ubi_volume {
300 	struct device dev;
301 	struct cdev cdev;
302 	struct ubi_device *ubi;
303 	int vol_id;
304 	int ref_count;
305 	int readers;
306 	int writers;
307 	int exclusive;
308 
309 	int reserved_pebs;
310 	int vol_type;
311 	int usable_leb_size;
312 	int used_ebs;
313 #ifndef __UBOOT__
314 	int last_eb_bytes;
315 #else
316 	u32 last_eb_bytes;
317 #endif
318 	long long used_bytes;
319 	int alignment;
320 	int data_pad;
321 	int name_len;
322 	char name[UBI_VOL_NAME_MAX + 1];
323 
324 	int upd_ebs;
325 	int ch_lnum;
326 	long long upd_bytes;
327 	long long upd_received;
328 	void *upd_buf;
329 
330 	int *eba_tbl;
331 	unsigned int checked:1;
332 	unsigned int corrupted:1;
333 	unsigned int upd_marker:1;
334 	unsigned int updating:1;
335 	unsigned int changing_leb:1;
336 	unsigned int direct_writes:1;
337 };
338 
339 /**
340  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
341  * @vol: reference to the corresponding volume description object
342  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
343  */
344 struct ubi_volume_desc {
345 	struct ubi_volume *vol;
346 	int mode;
347 };
348 
349 struct ubi_wl_entry;
350 
351 /**
352  * struct ubi_debug_info - debugging information for an UBI device.
353  *
354  * @chk_gen: if UBI general extra checks are enabled
355  * @chk_io: if UBI I/O extra checks are enabled
356  * @disable_bgt: disable the background task for testing purposes
357  * @emulate_bitflips: emulate bit-flips for testing purposes
358  * @emulate_io_failures: emulate write/erase failures for testing purposes
359  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
360  * @dfs_dir: direntry object of the UBI device debugfs directory
361  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
362  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
363  * @dfs_disable_bgt: debugfs knob to disable the background task
364  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
365  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
366  */
367 struct ubi_debug_info {
368 	unsigned int chk_gen:1;
369 	unsigned int chk_io:1;
370 	unsigned int disable_bgt:1;
371 	unsigned int emulate_bitflips:1;
372 	unsigned int emulate_io_failures:1;
373 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
374 	struct dentry *dfs_dir;
375 	struct dentry *dfs_chk_gen;
376 	struct dentry *dfs_chk_io;
377 	struct dentry *dfs_disable_bgt;
378 	struct dentry *dfs_emulate_bitflips;
379 	struct dentry *dfs_emulate_io_failures;
380 };
381 
382 /**
383  * struct ubi_device - UBI device description structure
384  * @dev: UBI device object to use the the Linux device model
385  * @cdev: character device object to create character device
386  * @ubi_num: UBI device number
387  * @ubi_name: UBI device name
388  * @vol_count: number of volumes in this UBI device
389  * @volumes: volumes of this UBI device
390  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
391  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
392  *                @vol->readers, @vol->writers, @vol->exclusive,
393  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
394  * @ref_count: count of references on the UBI device
395  * @image_seq: image sequence number recorded on EC headers
396  *
397  * @rsvd_pebs: count of reserved physical eraseblocks
398  * @avail_pebs: count of available physical eraseblocks
399  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
400  *                 handling
401  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
402  *
403  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
404  *                     of UBI initialization
405  * @vtbl_slots: how many slots are available in the volume table
406  * @vtbl_size: size of the volume table in bytes
407  * @vtbl: in-RAM volume table copy
408  * @device_mutex: protects on-flash volume table and serializes volume
409  *                creation, deletion, update, re-size, re-name and set
410  *                property
411  *
412  * @max_ec: current highest erase counter value
413  * @mean_ec: current mean erase counter value
414  *
415  * @global_sqnum: global sequence number
416  * @ltree_lock: protects the lock tree and @global_sqnum
417  * @ltree: the lock tree
418  * @alc_mutex: serializes "atomic LEB change" operations
419  *
420  * @fm_disabled: non-zero if fastmap is disabled (default)
421  * @fm: in-memory data structure of the currently used fastmap
422  * @fm_pool: in-memory data structure of the fastmap pool
423  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
424  *		sub-system
425  * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
426  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
427  * @fm_size: fastmap size in bytes
428  * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
429  * @fm_work: fastmap work queue
430  *
431  * @used: RB-tree of used physical eraseblocks
432  * @erroneous: RB-tree of erroneous used physical eraseblocks
433  * @free: RB-tree of free physical eraseblocks
434  * @free_count: Contains the number of elements in @free
435  * @scrub: RB-tree of physical eraseblocks which need scrubbing
436  * @pq: protection queue (contain physical eraseblocks which are temporarily
437  *      protected from the wear-leveling worker)
438  * @pq_head: protection queue head
439  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
440  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
441  *	     @erroneous, and @erroneous_peb_count fields
442  * @move_mutex: serializes eraseblock moves
443  * @work_sem: synchronizes the WL worker with use tasks
444  * @wl_scheduled: non-zero if the wear-leveling was scheduled
445  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
446  *             physical eraseblock
447  * @move_from: physical eraseblock from where the data is being moved
448  * @move_to: physical eraseblock where the data is being moved to
449  * @move_to_put: if the "to" PEB was put
450  * @works: list of pending works
451  * @works_count: count of pending works
452  * @bgt_thread: background thread description object
453  * @thread_enabled: if the background thread is enabled
454  * @bgt_name: background thread name
455  *
456  * @flash_size: underlying MTD device size (in bytes)
457  * @peb_count: count of physical eraseblocks on the MTD device
458  * @peb_size: physical eraseblock size
459  * @bad_peb_limit: top limit of expected bad physical eraseblocks
460  * @bad_peb_count: count of bad physical eraseblocks
461  * @good_peb_count: count of good physical eraseblocks
462  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
463  *                  used by UBI)
464  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
465  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
466  * @min_io_size: minimal input/output unit size of the underlying MTD device
467  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
468  * @ro_mode: if the UBI device is in read-only mode
469  * @leb_size: logical eraseblock size
470  * @leb_start: starting offset of logical eraseblocks within physical
471  *             eraseblocks
472  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
473  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
474  * @vid_hdr_offset: starting offset of the volume identifier header (might be
475  *                  unaligned)
476  * @vid_hdr_aloffset: starting offset of the VID header aligned to
477  * @hdrs_min_io_size
478  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
479  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
480  *               not
481  * @nor_flash: non-zero if working on top of NOR flash
482  * @max_write_size: maximum amount of bytes the underlying flash can write at a
483  *                  time (MTD write buffer size)
484  * @mtd: MTD device descriptor
485  *
486  * @peb_buf: a buffer of PEB size used for different purposes
487  * @buf_mutex: protects @peb_buf
488  * @ckvol_mutex: serializes static volume checking when opening
489  *
490  * @dbg: debugging information for this UBI device
491  */
492 struct ubi_device {
493 	struct cdev cdev;
494 	struct device dev;
495 	int ubi_num;
496 	char ubi_name[sizeof(UBI_NAME_STR)+5];
497 	int vol_count;
498 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
499 	spinlock_t volumes_lock;
500 	int ref_count;
501 	int image_seq;
502 
503 	int rsvd_pebs;
504 	int avail_pebs;
505 	int beb_rsvd_pebs;
506 	int beb_rsvd_level;
507 	int bad_peb_limit;
508 
509 	int autoresize_vol_id;
510 	int vtbl_slots;
511 	int vtbl_size;
512 	struct ubi_vtbl_record *vtbl;
513 	struct mutex device_mutex;
514 
515 	int max_ec;
516 	/* Note, mean_ec is not updated run-time - should be fixed */
517 	int mean_ec;
518 
519 	/* EBA sub-system's stuff */
520 	unsigned long long global_sqnum;
521 	spinlock_t ltree_lock;
522 	struct rb_root ltree;
523 	struct mutex alc_mutex;
524 
525 	/* Fastmap stuff */
526 	int fm_disabled;
527 	struct ubi_fastmap_layout *fm;
528 	struct ubi_fm_pool fm_pool;
529 	struct ubi_fm_pool fm_wl_pool;
530 	struct rw_semaphore fm_sem;
531 	struct mutex fm_mutex;
532 	void *fm_buf;
533 	size_t fm_size;
534 #ifndef __UBOOT__
535 	struct work_struct fm_work;
536 #endif
537 
538 	/* Wear-leveling sub-system's stuff */
539 	struct rb_root used;
540 	struct rb_root erroneous;
541 	struct rb_root free;
542 	int free_count;
543 	struct rb_root scrub;
544 	struct list_head pq[UBI_PROT_QUEUE_LEN];
545 	int pq_head;
546 	spinlock_t wl_lock;
547 	struct mutex move_mutex;
548 	struct rw_semaphore work_sem;
549 	int wl_scheduled;
550 	struct ubi_wl_entry **lookuptbl;
551 	struct ubi_wl_entry *move_from;
552 	struct ubi_wl_entry *move_to;
553 	int move_to_put;
554 	struct list_head works;
555 	int works_count;
556 	struct task_struct *bgt_thread;
557 	int thread_enabled;
558 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
559 
560 	/* I/O sub-system's stuff */
561 	long long flash_size;
562 	int peb_count;
563 	int peb_size;
564 	int bad_peb_count;
565 	int good_peb_count;
566 	int corr_peb_count;
567 	int erroneous_peb_count;
568 	int max_erroneous;
569 	int min_io_size;
570 	int hdrs_min_io_size;
571 	int ro_mode;
572 	int leb_size;
573 	int leb_start;
574 	int ec_hdr_alsize;
575 	int vid_hdr_alsize;
576 	int vid_hdr_offset;
577 	int vid_hdr_aloffset;
578 	int vid_hdr_shift;
579 	unsigned int bad_allowed:1;
580 	unsigned int nor_flash:1;
581 	int max_write_size;
582 	struct mtd_info *mtd;
583 
584 	void *peb_buf;
585 	struct mutex buf_mutex;
586 	struct mutex ckvol_mutex;
587 
588 	struct ubi_debug_info dbg;
589 };
590 
591 /**
592  * struct ubi_ainf_peb - attach information about a physical eraseblock.
593  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
594  * @pnum: physical eraseblock number
595  * @vol_id: ID of the volume this LEB belongs to
596  * @lnum: logical eraseblock number
597  * @scrub: if this physical eraseblock needs scrubbing
598  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
599  * @sqnum: sequence number
600  * @u: unions RB-tree or @list links
601  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
602  * @u.list: link in one of the eraseblock lists
603  *
604  * One object of this type is allocated for each physical eraseblock when
605  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
606  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
607  */
608 struct ubi_ainf_peb {
609 	int ec;
610 	int pnum;
611 	int vol_id;
612 	int lnum;
613 	unsigned int scrub:1;
614 	unsigned int copy_flag:1;
615 	unsigned long long sqnum;
616 	union {
617 		struct rb_node rb;
618 		struct list_head list;
619 	} u;
620 };
621 
622 /**
623  * struct ubi_ainf_volume - attaching information about a volume.
624  * @vol_id: volume ID
625  * @highest_lnum: highest logical eraseblock number in this volume
626  * @leb_count: number of logical eraseblocks in this volume
627  * @vol_type: volume type
628  * @used_ebs: number of used logical eraseblocks in this volume (only for
629  *            static volumes)
630  * @last_data_size: amount of data in the last logical eraseblock of this
631  *                  volume (always equivalent to the usable logical eraseblock
632  *                  size in case of dynamic volumes)
633  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
634  *            are not used (due to volume alignment)
635  * @compat: compatibility flags of this volume
636  * @rb: link in the volume RB-tree
637  * @root: root of the RB-tree containing all the eraseblock belonging to this
638  *        volume (&struct ubi_ainf_peb objects)
639  *
640  * One object of this type is allocated for each volume when attaching an MTD
641  * device.
642  */
643 struct ubi_ainf_volume {
644 	int vol_id;
645 	int highest_lnum;
646 	int leb_count;
647 	int vol_type;
648 	int used_ebs;
649 	int last_data_size;
650 	int data_pad;
651 	int compat;
652 	struct rb_node rb;
653 	struct rb_root root;
654 };
655 
656 /**
657  * struct ubi_attach_info - MTD device attaching information.
658  * @volumes: root of the volume RB-tree
659  * @corr: list of corrupted physical eraseblocks
660  * @free: list of free physical eraseblocks
661  * @erase: list of physical eraseblocks which have to be erased
662  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
663  *         those belonging to "preserve"-compatible internal volumes)
664  * @corr_peb_count: count of PEBs in the @corr list
665  * @empty_peb_count: count of PEBs which are presumably empty (contain only
666  *                   0xFF bytes)
667  * @alien_peb_count: count of PEBs in the @alien list
668  * @bad_peb_count: count of bad physical eraseblocks
669  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
670  *                       as bad yet, but which look like bad
671  * @vols_found: number of volumes found
672  * @highest_vol_id: highest volume ID
673  * @is_empty: flag indicating whether the MTD device is empty or not
674  * @min_ec: lowest erase counter value
675  * @max_ec: highest erase counter value
676  * @max_sqnum: highest sequence number value
677  * @mean_ec: mean erase counter value
678  * @ec_sum: a temporary variable used when calculating @mean_ec
679  * @ec_count: a temporary variable used when calculating @mean_ec
680  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
681  *
682  * This data structure contains the result of attaching an MTD device and may
683  * be used by other UBI sub-systems to build final UBI data structures, further
684  * error-recovery and so on.
685  */
686 struct ubi_attach_info {
687 	struct rb_root volumes;
688 	struct list_head corr;
689 	struct list_head free;
690 	struct list_head erase;
691 	struct list_head alien;
692 	int corr_peb_count;
693 	int empty_peb_count;
694 	int alien_peb_count;
695 	int bad_peb_count;
696 	int maybe_bad_peb_count;
697 	int vols_found;
698 	int highest_vol_id;
699 	int is_empty;
700 	int min_ec;
701 	int max_ec;
702 	unsigned long long max_sqnum;
703 	int mean_ec;
704 	uint64_t ec_sum;
705 	int ec_count;
706 	struct kmem_cache *aeb_slab_cache;
707 };
708 
709 /**
710  * struct ubi_work - UBI work description data structure.
711  * @list: a link in the list of pending works
712  * @func: worker function
713  * @e: physical eraseblock to erase
714  * @vol_id: the volume ID on which this erasure is being performed
715  * @lnum: the logical eraseblock number
716  * @torture: if the physical eraseblock has to be tortured
717  * @anchor: produce a anchor PEB to by used by fastmap
718  *
719  * The @func pointer points to the worker function. If the @cancel argument is
720  * not zero, the worker has to free the resources and exit immediately. The
721  * worker has to return zero in case of success and a negative error code in
722  * case of failure.
723  */
724 struct ubi_work {
725 	struct list_head list;
726 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
727 	/* The below fields are only relevant to erasure works */
728 	struct ubi_wl_entry *e;
729 	int vol_id;
730 	int lnum;
731 	int torture;
732 	int anchor;
733 };
734 
735 #include "debug.h"
736 
737 extern struct kmem_cache *ubi_wl_entry_slab;
738 extern const struct file_operations ubi_ctrl_cdev_operations;
739 extern const struct file_operations ubi_cdev_operations;
740 extern const struct file_operations ubi_vol_cdev_operations;
741 extern struct class *ubi_class;
742 extern struct mutex ubi_devices_mutex;
743 extern struct blocking_notifier_head ubi_notifiers;
744 
745 /* attach.c */
746 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
747 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
748 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
749 				    int vol_id);
750 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
751 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
752 				       struct ubi_attach_info *ai);
753 int ubi_attach(struct ubi_device *ubi, int force_scan);
754 void ubi_destroy_ai(struct ubi_attach_info *ai);
755 
756 /* vtbl.c */
757 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
758 			   struct ubi_vtbl_record *vtbl_rec);
759 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
760 			    struct list_head *rename_list);
761 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
762 
763 /* vmt.c */
764 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
765 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
766 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
767 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
768 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
769 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
770 
771 /* upd.c */
772 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
773 		     long long bytes);
774 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
775 			 const void __user *buf, int count);
776 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
777 			 const struct ubi_leb_change_req *req);
778 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
779 			     const void __user *buf, int count);
780 
781 /* misc.c */
782 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
783 		      int length);
784 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
785 void ubi_update_reserved(struct ubi_device *ubi);
786 void ubi_calculate_reserved(struct ubi_device *ubi);
787 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
788 
789 /* gluebi.c */
790 #ifdef CONFIG_MTD_UBI_GLUEBI
791 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
792 int ubi_destroy_gluebi(struct ubi_volume *vol);
793 void ubi_gluebi_updated(struct ubi_volume *vol);
794 #else
795 #define ubi_create_gluebi(ubi, vol) 0
796 
797 static inline int ubi_destroy_gluebi(struct ubi_volume *vol)
798 {
799 	return 0;
800 }
801 
802 #define ubi_gluebi_updated(vol)
803 #endif
804 
805 /* eba.c */
806 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
807 		      int lnum);
808 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
809 		     void *buf, int offset, int len, int check);
810 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
811 		      const void *buf, int offset, int len);
812 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
813 			 int lnum, const void *buf, int len, int used_ebs);
814 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
815 			      int lnum, const void *buf, int len);
816 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
817 		     struct ubi_vid_hdr *vid_hdr);
818 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
819 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
820 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
821 		   struct ubi_attach_info *ai_scan);
822 
823 /* wl.c */
824 int ubi_wl_get_peb(struct ubi_device *ubi);
825 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
826 		   int pnum, int torture);
827 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
828 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
829 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
830 void ubi_wl_close(struct ubi_device *ubi);
831 int ubi_thread(void *u);
832 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
833 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
834 		      int lnum, int torture);
835 int ubi_is_erase_work(struct ubi_work *wrk);
836 void ubi_refill_pools(struct ubi_device *ubi);
837 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
838 
839 /* io.c */
840 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
841 		int len);
842 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
843 		 int len);
844 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
845 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
846 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
847 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
848 		       struct ubi_ec_hdr *ec_hdr, int verbose);
849 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
850 			struct ubi_ec_hdr *ec_hdr);
851 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
852 			struct ubi_vid_hdr *vid_hdr, int verbose);
853 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
854 			 struct ubi_vid_hdr *vid_hdr);
855 
856 /* build.c */
857 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
858 		       int vid_hdr_offset, int max_beb_per1024);
859 int ubi_detach_mtd_dev(int ubi_num, int anyway);
860 struct ubi_device *ubi_get_device(int ubi_num);
861 void ubi_put_device(struct ubi_device *ubi);
862 struct ubi_device *ubi_get_by_major(int major);
863 int ubi_major2num(int major);
864 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
865 		      int ntype);
866 int ubi_notify_all(struct ubi_device *ubi, int ntype,
867 		   struct notifier_block *nb);
868 int ubi_enumerate_volumes(struct notifier_block *nb);
869 void ubi_free_internal_volumes(struct ubi_device *ubi);
870 
871 /* kapi.c */
872 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
873 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
874 			    struct ubi_volume_info *vi);
875 /* scan.c */
876 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
877 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
878 
879 /* fastmap.c */
880 size_t ubi_calc_fm_size(struct ubi_device *ubi);
881 int ubi_update_fastmap(struct ubi_device *ubi);
882 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
883 		     int fm_anchor);
884 
885 /* block.c */
886 #ifdef CONFIG_MTD_UBI_BLOCK
887 int ubiblock_init(void);
888 void ubiblock_exit(void);
889 int ubiblock_create(struct ubi_volume_info *vi);
890 int ubiblock_remove(struct ubi_volume_info *vi);
891 #else
892 static inline int ubiblock_init(void) { return 0; }
893 static inline void ubiblock_exit(void) {}
894 static inline int ubiblock_create(struct ubi_volume_info *vi)
895 {
896 	return -ENOSYS;
897 }
898 static inline int ubiblock_remove(struct ubi_volume_info *vi)
899 {
900 	return -ENOSYS;
901 }
902 #endif
903 
904 
905 /*
906  * ubi_rb_for_each_entry - walk an RB-tree.
907  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
908  * @pos: a pointer to RB-tree entry type to use as a loop counter
909  * @root: RB-tree's root
910  * @member: the name of the 'struct rb_node' within the RB-tree entry
911  */
912 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
913 	for (rb = rb_first(root),                                            \
914 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
915 	     rb;                                                             \
916 	     rb = rb_next(rb),                                               \
917 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
918 
919 /*
920  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
921  *
922  * @av: volume attaching information
923  * @aeb: attaching eraseblock information
924  * @list: the list to move to
925  */
926 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
927 					 struct ubi_ainf_peb *aeb,
928 					 struct list_head *list)
929 {
930 		rb_erase(&aeb->u.rb, &av->root);
931 		list_add_tail(&aeb->u.list, list);
932 }
933 
934 /**
935  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
936  * @ubi: UBI device description object
937  * @gfp_flags: GFP flags to allocate with
938  *
939  * This function returns a pointer to the newly allocated and zero-filled
940  * volume identifier header object in case of success and %NULL in case of
941  * failure.
942  */
943 static inline struct ubi_vid_hdr *
944 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
945 {
946 	void *vid_hdr;
947 
948 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
949 	if (!vid_hdr)
950 		return NULL;
951 
952 	/*
953 	 * VID headers may be stored at un-aligned flash offsets, so we shift
954 	 * the pointer.
955 	 */
956 	return vid_hdr + ubi->vid_hdr_shift;
957 }
958 
959 /**
960  * ubi_free_vid_hdr - free a volume identifier header object.
961  * @ubi: UBI device description object
962  * @vid_hdr: the object to free
963  */
964 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
965 				    struct ubi_vid_hdr *vid_hdr)
966 {
967 	void *p = vid_hdr;
968 
969 	if (!p)
970 		return;
971 
972 	kfree(p - ubi->vid_hdr_shift);
973 }
974 
975 /*
976  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
977  * the beginning of the logical eraseblock, not to the beginning of the
978  * physical eraseblock.
979  */
980 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
981 				   int pnum, int offset, int len)
982 {
983 	ubi_assert(offset >= 0);
984 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
985 }
986 
987 /*
988  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
989  * the beginning of the logical eraseblock, not to the beginning of the
990  * physical eraseblock.
991  */
992 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
993 				    int pnum, int offset, int len)
994 {
995 	ubi_assert(offset >= 0);
996 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
997 }
998 
999 /**
1000  * ubi_ro_mode - switch to read-only mode.
1001  * @ubi: UBI device description object
1002  */
1003 static inline void ubi_ro_mode(struct ubi_device *ubi)
1004 {
1005 	if (!ubi->ro_mode) {
1006 		ubi->ro_mode = 1;
1007 		ubi_warn("switch to read-only mode");
1008 		dump_stack();
1009 	}
1010 }
1011 
1012 /**
1013  * vol_id2idx - get table index by volume ID.
1014  * @ubi: UBI device description object
1015  * @vol_id: volume ID
1016  */
1017 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1018 {
1019 	if (vol_id >= UBI_INTERNAL_VOL_START)
1020 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1021 	else
1022 		return vol_id;
1023 }
1024 
1025 /**
1026  * idx2vol_id - get volume ID by table index.
1027  * @ubi: UBI device description object
1028  * @idx: table index
1029  */
1030 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1031 {
1032 	if (idx >= ubi->vtbl_slots)
1033 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1034 	else
1035 		return idx;
1036 }
1037 
1038 #endif /* !__UBI_UBI_H__ */
1039