xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 8684014d)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  * Copyright (c) Nokia Corporation, 2006, 2007
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13  * the GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  *
19  * Author: Artem Bityutskiy (Битюцкий Артём)
20  */
21 
22 #ifndef __UBI_UBI_H__
23 #define __UBI_UBI_H__
24 
25 #include <linux/types.h>
26 #include <linux/list.h>
27 #include <linux/rbtree.h>
28 #include <linux/sched.h>
29 #include <linux/wait.h>
30 #include <linux/mutex.h>
31 #include <linux/rwsem.h>
32 #include <linux/spinlock.h>
33 #include <linux/fs.h>
34 #include <linux/cdev.h>
35 #include <linux/device.h>
36 #include <linux/slab.h>
37 #include <linux/string.h>
38 #include <linux/vmalloc.h>
39 #include <linux/notifier.h>
40 #include <linux/mtd/mtd.h>
41 #include <linux/mtd/ubi.h>
42 #include <asm/pgtable.h>
43 
44 #include "ubi-media.h"
45 
46 /* Maximum number of supported UBI devices */
47 #define UBI_MAX_DEVICES 32
48 
49 /* UBI name used for character devices, sysfs, etc */
50 #define UBI_NAME_STR "ubi"
51 
52 /* Normal UBI messages */
53 #define ubi_msg(ubi, fmt, ...) pr_notice("UBI-%d: %s:" fmt "\n", \
54 					 ubi->ubi_num, __func__, ##__VA_ARGS__)
55 /* UBI warning messages */
56 #define ubi_warn(ubi, fmt, ...) pr_warn("UBI-%d warning: %s: " fmt "\n", \
57 					ubi->ubi_num, __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(ubi, fmt, ...) pr_err("UBI-%d error: %s: " fmt "\n", \
60 				      ubi->ubi_num, __func__, ##__VA_ARGS__)
61 
62 /* Background thread name pattern */
63 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
64 
65 /*
66  * This marker in the EBA table means that the LEB is um-mapped.
67  * NOTE! It has to have the same value as %UBI_ALL.
68  */
69 #define UBI_LEB_UNMAPPED -1
70 
71 /*
72  * In case of errors, UBI tries to repeat the operation several times before
73  * returning error. The below constant defines how many times UBI re-tries.
74  */
75 #define UBI_IO_RETRIES 3
76 
77 /*
78  * Length of the protection queue. The length is effectively equivalent to the
79  * number of (global) erase cycles PEBs are protected from the wear-leveling
80  * worker.
81  */
82 #define UBI_PROT_QUEUE_LEN 10
83 
84 /* The volume ID/LEB number/erase counter is unknown */
85 #define UBI_UNKNOWN -1
86 
87 /*
88  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
89  * + 2 for the number plus 1 for the trailing zero byte.
90  */
91 #define UBI_DFS_DIR_NAME "ubi%d"
92 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
93 
94 /*
95  * Error codes returned by the I/O sub-system.
96  *
97  * UBI_IO_FF: the read region of flash contains only 0xFFs
98  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
99  *                     integrity error reported by the MTD driver
100  *                     (uncorrectable ECC error in case of NAND)
101  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
102  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
103  *                         data integrity error reported by the MTD driver
104  *                         (uncorrectable ECC error in case of NAND)
105  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
106  *
107  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
108  * be or'ed with other error code. But this is a big change because there are
109  * may callers, so it does not worth the risk of introducing a bug
110  */
111 enum {
112 	UBI_IO_FF = 1,
113 	UBI_IO_FF_BITFLIPS,
114 	UBI_IO_BAD_HDR,
115 	UBI_IO_BAD_HDR_EBADMSG,
116 	UBI_IO_BITFLIPS,
117 };
118 
119 /*
120  * Return codes of the 'ubi_eba_copy_leb()' function.
121  *
122  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
123  *                   PEB was put meanwhile, or there is I/O on the source PEB
124  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
125  *                     PEB
126  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
127  *                     PEB
128  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
129  *                     PEB
130  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
131  *                       target PEB
132  * MOVE_RETRY: retry scrubbing the PEB
133  */
134 enum {
135 	MOVE_CANCEL_RACE = 1,
136 	MOVE_SOURCE_RD_ERR,
137 	MOVE_TARGET_RD_ERR,
138 	MOVE_TARGET_WR_ERR,
139 	MOVE_TARGET_BITFLIPS,
140 	MOVE_RETRY,
141 };
142 
143 /*
144  * Return codes of the fastmap sub-system
145  *
146  * UBI_NO_FASTMAP: No fastmap super block was found
147  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
148  */
149 enum {
150 	UBI_NO_FASTMAP = 1,
151 	UBI_BAD_FASTMAP,
152 };
153 
154 /**
155  * struct ubi_wl_entry - wear-leveling entry.
156  * @u.rb: link in the corresponding (free/used) RB-tree
157  * @u.list: link in the protection queue
158  * @ec: erase counter
159  * @pnum: physical eraseblock number
160  *
161  * This data structure is used in the WL sub-system. Each physical eraseblock
162  * has a corresponding &struct wl_entry object which may be kept in different
163  * RB-trees. See WL sub-system for details.
164  */
165 struct ubi_wl_entry {
166 	union {
167 		struct rb_node rb;
168 		struct list_head list;
169 	} u;
170 	int ec;
171 	int pnum;
172 };
173 
174 /**
175  * struct ubi_ltree_entry - an entry in the lock tree.
176  * @rb: links RB-tree nodes
177  * @vol_id: volume ID of the locked logical eraseblock
178  * @lnum: locked logical eraseblock number
179  * @users: how many tasks are using this logical eraseblock or wait for it
180  * @mutex: read/write mutex to implement read/write access serialization to
181  *         the (@vol_id, @lnum) logical eraseblock
182  *
183  * This data structure is used in the EBA sub-system to implement per-LEB
184  * locking. When a logical eraseblock is being locked - corresponding
185  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
186  * See EBA sub-system for details.
187  */
188 struct ubi_ltree_entry {
189 	struct rb_node rb;
190 	int vol_id;
191 	int lnum;
192 	int users;
193 	struct rw_semaphore mutex;
194 };
195 
196 /**
197  * struct ubi_rename_entry - volume re-name description data structure.
198  * @new_name_len: new volume name length
199  * @new_name: new volume name
200  * @remove: if not zero, this volume should be removed, not re-named
201  * @desc: descriptor of the volume
202  * @list: links re-name entries into a list
203  *
204  * This data structure is utilized in the multiple volume re-name code. Namely,
205  * UBI first creates a list of &struct ubi_rename_entry objects from the
206  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
207  * the job.
208  */
209 struct ubi_rename_entry {
210 	int new_name_len;
211 	char new_name[UBI_VOL_NAME_MAX + 1];
212 	int remove;
213 	struct ubi_volume_desc *desc;
214 	struct list_head list;
215 };
216 
217 struct ubi_volume_desc;
218 
219 /**
220  * struct ubi_fastmap_layout - in-memory fastmap data structure.
221  * @e: PEBs used by the current fastmap
222  * @to_be_tortured: if non-zero tortured this PEB
223  * @used_blocks: number of used PEBs
224  * @max_pool_size: maximal size of the user pool
225  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
226  */
227 struct ubi_fastmap_layout {
228 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
229 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
230 	int used_blocks;
231 	int max_pool_size;
232 	int max_wl_pool_size;
233 };
234 
235 /**
236  * struct ubi_fm_pool - in-memory fastmap pool
237  * @pebs: PEBs in this pool
238  * @used: number of used PEBs
239  * @size: total number of PEBs in this pool
240  * @max_size: maximal size of the pool
241  *
242  * A pool gets filled with up to max_size.
243  * If all PEBs within the pool are used a new fastmap will be written
244  * to the flash and the pool gets refilled with empty PEBs.
245  *
246  */
247 struct ubi_fm_pool {
248 	int pebs[UBI_FM_MAX_POOL_SIZE];
249 	int used;
250 	int size;
251 	int max_size;
252 };
253 
254 /**
255  * struct ubi_volume - UBI volume description data structure.
256  * @dev: device object to make use of the the Linux device model
257  * @cdev: character device object to create character device
258  * @ubi: reference to the UBI device description object
259  * @vol_id: volume ID
260  * @ref_count: volume reference count
261  * @readers: number of users holding this volume in read-only mode
262  * @writers: number of users holding this volume in read-write mode
263  * @exclusive: whether somebody holds this volume in exclusive mode
264  *
265  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
266  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
267  * @usable_leb_size: logical eraseblock size without padding
268  * @used_ebs: how many logical eraseblocks in this volume contain data
269  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
270  * @used_bytes: how many bytes of data this volume contains
271  * @alignment: volume alignment
272  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
273  *            satisfy the requested alignment
274  * @name_len: volume name length
275  * @name: volume name
276  *
277  * @upd_ebs: how many eraseblocks are expected to be updated
278  * @ch_lnum: LEB number which is being changing by the atomic LEB change
279  *           operation
280  * @upd_bytes: how many bytes are expected to be received for volume update or
281  *             atomic LEB change
282  * @upd_received: how many bytes were already received for volume update or
283  *                atomic LEB change
284  * @upd_buf: update buffer which is used to collect update data or data for
285  *           atomic LEB change
286  *
287  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
288  * @checked: %1 if this static volume was checked
289  * @corrupted: %1 if the volume is corrupted (static volumes only)
290  * @upd_marker: %1 if the update marker is set for this volume
291  * @updating: %1 if the volume is being updated
292  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
293  * @direct_writes: %1 if direct writes are enabled for this volume
294  *
295  * The @corrupted field indicates that the volume's contents is corrupted.
296  * Since UBI protects only static volumes, this field is not relevant to
297  * dynamic volumes - it is user's responsibility to assure their data
298  * integrity.
299  *
300  * The @upd_marker flag indicates that this volume is either being updated at
301  * the moment or is damaged because of an unclean reboot.
302  */
303 struct ubi_volume {
304 	struct device dev;
305 	struct cdev cdev;
306 	struct ubi_device *ubi;
307 	int vol_id;
308 	int ref_count;
309 	int readers;
310 	int writers;
311 	int exclusive;
312 
313 	int reserved_pebs;
314 	int vol_type;
315 	int usable_leb_size;
316 	int used_ebs;
317 	int last_eb_bytes;
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: used to wait for all the scheduled works to finish and prevent
444  * new works from being submitted
445  * @wl_scheduled: non-zero if the wear-leveling was scheduled
446  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
447  *             physical eraseblock
448  * @move_from: physical eraseblock from where the data is being moved
449  * @move_to: physical eraseblock where the data is being moved to
450  * @move_to_put: if the "to" PEB was put
451  * @works: list of pending works
452  * @works_count: count of pending works
453  * @bgt_thread: background thread description object
454  * @thread_enabled: if the background thread is enabled
455  * @bgt_name: background thread name
456  *
457  * @flash_size: underlying MTD device size (in bytes)
458  * @peb_count: count of physical eraseblocks on the MTD device
459  * @peb_size: physical eraseblock size
460  * @bad_peb_limit: top limit of expected bad physical eraseblocks
461  * @bad_peb_count: count of bad physical eraseblocks
462  * @good_peb_count: count of good physical eraseblocks
463  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
464  *                  used by UBI)
465  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
466  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
467  * @min_io_size: minimal input/output unit size of the underlying MTD device
468  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
469  * @ro_mode: if the UBI device is in read-only mode
470  * @leb_size: logical eraseblock size
471  * @leb_start: starting offset of logical eraseblocks within physical
472  *             eraseblocks
473  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
474  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
475  * @vid_hdr_offset: starting offset of the volume identifier header (might be
476  *                  unaligned)
477  * @vid_hdr_aloffset: starting offset of the VID header aligned to
478  * @hdrs_min_io_size
479  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
480  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
481  *               not
482  * @nor_flash: non-zero if working on top of NOR flash
483  * @max_write_size: maximum amount of bytes the underlying flash can write at a
484  *                  time (MTD write buffer size)
485  * @mtd: MTD device descriptor
486  *
487  * @peb_buf: a buffer of PEB size used for different purposes
488  * @buf_mutex: protects @peb_buf
489  * @ckvol_mutex: serializes static volume checking when opening
490  *
491  * @dbg: debugging information for this UBI device
492  */
493 struct ubi_device {
494 	struct cdev cdev;
495 	struct device dev;
496 	int ubi_num;
497 	char ubi_name[sizeof(UBI_NAME_STR)+5];
498 	int vol_count;
499 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
500 	spinlock_t volumes_lock;
501 	int ref_count;
502 	int image_seq;
503 
504 	int rsvd_pebs;
505 	int avail_pebs;
506 	int beb_rsvd_pebs;
507 	int beb_rsvd_level;
508 	int bad_peb_limit;
509 
510 	int autoresize_vol_id;
511 	int vtbl_slots;
512 	int vtbl_size;
513 	struct ubi_vtbl_record *vtbl;
514 	struct mutex device_mutex;
515 
516 	int max_ec;
517 	/* Note, mean_ec is not updated run-time - should be fixed */
518 	int mean_ec;
519 
520 	/* EBA sub-system's stuff */
521 	unsigned long long global_sqnum;
522 	spinlock_t ltree_lock;
523 	struct rb_root ltree;
524 	struct mutex alc_mutex;
525 
526 	/* Fastmap stuff */
527 	int fm_disabled;
528 	struct ubi_fastmap_layout *fm;
529 	struct ubi_fm_pool fm_pool;
530 	struct ubi_fm_pool fm_wl_pool;
531 	struct rw_semaphore fm_sem;
532 	struct mutex fm_mutex;
533 	void *fm_buf;
534 	size_t fm_size;
535 	struct work_struct fm_work;
536 
537 	/* Wear-leveling sub-system's stuff */
538 	struct rb_root used;
539 	struct rb_root erroneous;
540 	struct rb_root free;
541 	int free_count;
542 	struct rb_root scrub;
543 	struct list_head pq[UBI_PROT_QUEUE_LEN];
544 	int pq_head;
545 	spinlock_t wl_lock;
546 	struct mutex move_mutex;
547 	struct rw_semaphore work_sem;
548 	int wl_scheduled;
549 	struct ubi_wl_entry **lookuptbl;
550 	struct ubi_wl_entry *move_from;
551 	struct ubi_wl_entry *move_to;
552 	int move_to_put;
553 	struct list_head works;
554 	int works_count;
555 	struct task_struct *bgt_thread;
556 	int thread_enabled;
557 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
558 
559 	/* I/O sub-system's stuff */
560 	long long flash_size;
561 	int peb_count;
562 	int peb_size;
563 	int bad_peb_count;
564 	int good_peb_count;
565 	int corr_peb_count;
566 	int erroneous_peb_count;
567 	int max_erroneous;
568 	int min_io_size;
569 	int hdrs_min_io_size;
570 	int ro_mode;
571 	int leb_size;
572 	int leb_start;
573 	int ec_hdr_alsize;
574 	int vid_hdr_alsize;
575 	int vid_hdr_offset;
576 	int vid_hdr_aloffset;
577 	int vid_hdr_shift;
578 	unsigned int bad_allowed:1;
579 	unsigned int nor_flash:1;
580 	int max_write_size;
581 	struct mtd_info *mtd;
582 
583 	void *peb_buf;
584 	struct mutex buf_mutex;
585 	struct mutex ckvol_mutex;
586 
587 	struct ubi_debug_info dbg;
588 };
589 
590 /**
591  * struct ubi_ainf_peb - attach information about a physical eraseblock.
592  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
593  * @pnum: physical eraseblock number
594  * @vol_id: ID of the volume this LEB belongs to
595  * @lnum: logical eraseblock number
596  * @scrub: if this physical eraseblock needs scrubbing
597  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
598  * @sqnum: sequence number
599  * @u: unions RB-tree or @list links
600  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
601  * @u.list: link in one of the eraseblock lists
602  *
603  * One object of this type is allocated for each physical eraseblock when
604  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
605  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
606  */
607 struct ubi_ainf_peb {
608 	int ec;
609 	int pnum;
610 	int vol_id;
611 	int lnum;
612 	unsigned int scrub:1;
613 	unsigned int copy_flag:1;
614 	unsigned long long sqnum;
615 	union {
616 		struct rb_node rb;
617 		struct list_head list;
618 	} u;
619 };
620 
621 /**
622  * struct ubi_ainf_volume - attaching information about a volume.
623  * @vol_id: volume ID
624  * @highest_lnum: highest logical eraseblock number in this volume
625  * @leb_count: number of logical eraseblocks in this volume
626  * @vol_type: volume type
627  * @used_ebs: number of used logical eraseblocks in this volume (only for
628  *            static volumes)
629  * @last_data_size: amount of data in the last logical eraseblock of this
630  *                  volume (always equivalent to the usable logical eraseblock
631  *                  size in case of dynamic volumes)
632  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
633  *            are not used (due to volume alignment)
634  * @compat: compatibility flags of this volume
635  * @rb: link in the volume RB-tree
636  * @root: root of the RB-tree containing all the eraseblock belonging to this
637  *        volume (&struct ubi_ainf_peb objects)
638  *
639  * One object of this type is allocated for each volume when attaching an MTD
640  * device.
641  */
642 struct ubi_ainf_volume {
643 	int vol_id;
644 	int highest_lnum;
645 	int leb_count;
646 	int vol_type;
647 	int used_ebs;
648 	int last_data_size;
649 	int data_pad;
650 	int compat;
651 	struct rb_node rb;
652 	struct rb_root root;
653 };
654 
655 /**
656  * struct ubi_attach_info - MTD device attaching information.
657  * @volumes: root of the volume RB-tree
658  * @corr: list of corrupted physical eraseblocks
659  * @free: list of free physical eraseblocks
660  * @erase: list of physical eraseblocks which have to be erased
661  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
662  *         those belonging to "preserve"-compatible internal volumes)
663  * @corr_peb_count: count of PEBs in the @corr list
664  * @empty_peb_count: count of PEBs which are presumably empty (contain only
665  *                   0xFF bytes)
666  * @alien_peb_count: count of PEBs in the @alien list
667  * @bad_peb_count: count of bad physical eraseblocks
668  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
669  *                       as bad yet, but which look like bad
670  * @vols_found: number of volumes found
671  * @highest_vol_id: highest volume ID
672  * @is_empty: flag indicating whether the MTD device is empty or not
673  * @min_ec: lowest erase counter value
674  * @max_ec: highest erase counter value
675  * @max_sqnum: highest sequence number value
676  * @mean_ec: mean erase counter value
677  * @ec_sum: a temporary variable used when calculating @mean_ec
678  * @ec_count: a temporary variable used when calculating @mean_ec
679  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
680  *
681  * This data structure contains the result of attaching an MTD device and may
682  * be used by other UBI sub-systems to build final UBI data structures, further
683  * error-recovery and so on.
684  */
685 struct ubi_attach_info {
686 	struct rb_root volumes;
687 	struct list_head corr;
688 	struct list_head free;
689 	struct list_head erase;
690 	struct list_head alien;
691 	int corr_peb_count;
692 	int empty_peb_count;
693 	int alien_peb_count;
694 	int bad_peb_count;
695 	int maybe_bad_peb_count;
696 	int vols_found;
697 	int highest_vol_id;
698 	int is_empty;
699 	int min_ec;
700 	int max_ec;
701 	unsigned long long max_sqnum;
702 	int mean_ec;
703 	uint64_t ec_sum;
704 	int ec_count;
705 	struct kmem_cache *aeb_slab_cache;
706 };
707 
708 /**
709  * struct ubi_work - UBI work description data structure.
710  * @list: a link in the list of pending works
711  * @func: worker function
712  * @e: physical eraseblock to erase
713  * @vol_id: the volume ID on which this erasure is being performed
714  * @lnum: the logical eraseblock number
715  * @torture: if the physical eraseblock has to be tortured
716  * @anchor: produce a anchor PEB to by used by fastmap
717  *
718  * The @func pointer points to the worker function. If the @shutdown argument is
719  * not zero, the worker has to free the resources and exit immediately as the
720  * WL sub-system is shutting down.
721  * The 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 shutdown);
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 /* eba.c */
790 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
791 		      int lnum);
792 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
793 		     void *buf, int offset, int len, int check);
794 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
795 		      const void *buf, int offset, int len);
796 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
797 			 int lnum, const void *buf, int len, int used_ebs);
798 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
799 			      int lnum, const void *buf, int len);
800 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
801 		     struct ubi_vid_hdr *vid_hdr);
802 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
803 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
804 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
805 		   struct ubi_attach_info *ai_scan);
806 
807 /* wl.c */
808 int ubi_wl_get_peb(struct ubi_device *ubi);
809 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
810 		   int pnum, int torture);
811 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
812 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
813 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
814 void ubi_wl_close(struct ubi_device *ubi);
815 int ubi_thread(void *u);
816 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
817 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
818 		      int lnum, int torture);
819 int ubi_is_erase_work(struct ubi_work *wrk);
820 void ubi_refill_pools(struct ubi_device *ubi);
821 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
822 
823 /* io.c */
824 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
825 		int len);
826 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
827 		 int len);
828 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
829 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
830 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
831 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
832 		       struct ubi_ec_hdr *ec_hdr, int verbose);
833 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
834 			struct ubi_ec_hdr *ec_hdr);
835 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
836 			struct ubi_vid_hdr *vid_hdr, int verbose);
837 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
838 			 struct ubi_vid_hdr *vid_hdr);
839 
840 /* build.c */
841 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
842 		       int vid_hdr_offset, int max_beb_per1024);
843 int ubi_detach_mtd_dev(int ubi_num, int anyway);
844 struct ubi_device *ubi_get_device(int ubi_num);
845 void ubi_put_device(struct ubi_device *ubi);
846 struct ubi_device *ubi_get_by_major(int major);
847 int ubi_major2num(int major);
848 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
849 		      int ntype);
850 int ubi_notify_all(struct ubi_device *ubi, int ntype,
851 		   struct notifier_block *nb);
852 int ubi_enumerate_volumes(struct notifier_block *nb);
853 void ubi_free_internal_volumes(struct ubi_device *ubi);
854 
855 /* kapi.c */
856 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
857 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
858 			    struct ubi_volume_info *vi);
859 /* scan.c */
860 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
861 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
862 
863 /* fastmap.c */
864 size_t ubi_calc_fm_size(struct ubi_device *ubi);
865 int ubi_update_fastmap(struct ubi_device *ubi);
866 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
867 		     int fm_anchor);
868 
869 /* block.c */
870 #ifdef CONFIG_MTD_UBI_BLOCK
871 int ubiblock_init(void);
872 void ubiblock_exit(void);
873 int ubiblock_create(struct ubi_volume_info *vi);
874 int ubiblock_remove(struct ubi_volume_info *vi);
875 #else
876 static inline int ubiblock_init(void) { return 0; }
877 static inline void ubiblock_exit(void) {}
878 static inline int ubiblock_create(struct ubi_volume_info *vi)
879 {
880 	return -ENOSYS;
881 }
882 static inline int ubiblock_remove(struct ubi_volume_info *vi)
883 {
884 	return -ENOSYS;
885 }
886 #endif
887 
888 
889 /*
890  * ubi_rb_for_each_entry - walk an RB-tree.
891  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
892  * @pos: a pointer to RB-tree entry type to use as a loop counter
893  * @root: RB-tree's root
894  * @member: the name of the 'struct rb_node' within the RB-tree entry
895  */
896 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
897 	for (rb = rb_first(root),                                            \
898 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
899 	     rb;                                                             \
900 	     rb = rb_next(rb),                                               \
901 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
902 
903 /*
904  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
905  *
906  * @av: volume attaching information
907  * @aeb: attaching eraseblock information
908  * @list: the list to move to
909  */
910 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
911 					 struct ubi_ainf_peb *aeb,
912 					 struct list_head *list)
913 {
914 		rb_erase(&aeb->u.rb, &av->root);
915 		list_add_tail(&aeb->u.list, list);
916 }
917 
918 /**
919  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
920  * @ubi: UBI device description object
921  * @gfp_flags: GFP flags to allocate with
922  *
923  * This function returns a pointer to the newly allocated and zero-filled
924  * volume identifier header object in case of success and %NULL in case of
925  * failure.
926  */
927 static inline struct ubi_vid_hdr *
928 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
929 {
930 	void *vid_hdr;
931 
932 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
933 	if (!vid_hdr)
934 		return NULL;
935 
936 	/*
937 	 * VID headers may be stored at un-aligned flash offsets, so we shift
938 	 * the pointer.
939 	 */
940 	return vid_hdr + ubi->vid_hdr_shift;
941 }
942 
943 /**
944  * ubi_free_vid_hdr - free a volume identifier header object.
945  * @ubi: UBI device description object
946  * @vid_hdr: the object to free
947  */
948 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
949 				    struct ubi_vid_hdr *vid_hdr)
950 {
951 	void *p = vid_hdr;
952 
953 	if (!p)
954 		return;
955 
956 	kfree(p - ubi->vid_hdr_shift);
957 }
958 
959 /*
960  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
961  * the beginning of the logical eraseblock, not to the beginning of the
962  * physical eraseblock.
963  */
964 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
965 				   int pnum, int offset, int len)
966 {
967 	ubi_assert(offset >= 0);
968 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
969 }
970 
971 /*
972  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
973  * the beginning of the logical eraseblock, not to the beginning of the
974  * physical eraseblock.
975  */
976 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
977 				    int pnum, int offset, int len)
978 {
979 	ubi_assert(offset >= 0);
980 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
981 }
982 
983 /**
984  * ubi_ro_mode - switch to read-only mode.
985  * @ubi: UBI device description object
986  */
987 static inline void ubi_ro_mode(struct ubi_device *ubi)
988 {
989 	if (!ubi->ro_mode) {
990 		ubi->ro_mode = 1;
991 		ubi_warn(ubi, "switch to read-only mode");
992 		dump_stack();
993 	}
994 }
995 
996 /**
997  * vol_id2idx - get table index by volume ID.
998  * @ubi: UBI device description object
999  * @vol_id: volume ID
1000  */
1001 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1002 {
1003 	if (vol_id >= UBI_INTERNAL_VOL_START)
1004 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1005 	else
1006 		return vol_id;
1007 }
1008 
1009 /**
1010  * idx2vol_id - get volume ID by table index.
1011  * @ubi: UBI device description object
1012  * @idx: table index
1013  */
1014 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1015 {
1016 	if (idx >= ubi->vtbl_slots)
1017 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1018 	else
1019 		return idx;
1020 }
1021 
1022 #endif /* !__UBI_UBI_H__ */
1023