xref: /linux/drivers/mtd/ubi/ubi.h (revision 2a2c74b2efcb1a0ca3fdcb5fbb96ad8de6a29177)
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(fmt, ...) pr_notice("UBI: " fmt "\n", ##__VA_ARGS__)
54 /* UBI warning messages */
55 #define ubi_warn(fmt, ...) pr_warn("UBI warning: %s: " fmt "\n",  \
56 				   __func__, ##__VA_ARGS__)
57 /* UBI error messages */
58 #define ubi_err(fmt, ...) pr_err("UBI error: %s: " fmt "\n",      \
59 				 __func__, ##__VA_ARGS__)
60 
61 /* Background thread name pattern */
62 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
63 
64 /*
65  * This marker in the EBA table means that the LEB is um-mapped.
66  * NOTE! It has to have the same value as %UBI_ALL.
67  */
68 #define UBI_LEB_UNMAPPED -1
69 
70 /*
71  * In case of errors, UBI tries to repeat the operation several times before
72  * returning error. The below constant defines how many times UBI re-tries.
73  */
74 #define UBI_IO_RETRIES 3
75 
76 /*
77  * Length of the protection queue. The length is effectively equivalent to the
78  * number of (global) erase cycles PEBs are protected from the wear-leveling
79  * worker.
80  */
81 #define UBI_PROT_QUEUE_LEN 10
82 
83 /* The volume ID/LEB number/erase counter is unknown */
84 #define UBI_UNKNOWN -1
85 
86 /*
87  * The UBI debugfs directory name pattern and maximum name length (3 for "ubi"
88  * + 2 for the number plus 1 for the trailing zero byte.
89  */
90 #define UBI_DFS_DIR_NAME "ubi%d"
91 #define UBI_DFS_DIR_LEN  (3 + 2 + 1)
92 
93 /*
94  * Error codes returned by the I/O sub-system.
95  *
96  * UBI_IO_FF: the read region of flash contains only 0xFFs
97  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
98  *                     integrity error reported by the MTD driver
99  *                     (uncorrectable ECC error in case of NAND)
100  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
101  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
102  *                         data integrity error reported by the MTD driver
103  *                         (uncorrectable ECC error in case of NAND)
104  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
105  *
106  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
107  * be or'ed with other error code. But this is a big change because there are
108  * may callers, so it does not worth the risk of introducing a bug
109  */
110 enum {
111 	UBI_IO_FF = 1,
112 	UBI_IO_FF_BITFLIPS,
113 	UBI_IO_BAD_HDR,
114 	UBI_IO_BAD_HDR_EBADMSG,
115 	UBI_IO_BITFLIPS,
116 };
117 
118 /*
119  * Return codes of the 'ubi_eba_copy_leb()' function.
120  *
121  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
122  *                   PEB was put meanwhile, or there is I/O on the source PEB
123  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
124  *                     PEB
125  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
126  *                     PEB
127  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
128  *                     PEB
129  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
130  *                       target PEB
131  * MOVE_RETRY: retry scrubbing the PEB
132  */
133 enum {
134 	MOVE_CANCEL_RACE = 1,
135 	MOVE_SOURCE_RD_ERR,
136 	MOVE_TARGET_RD_ERR,
137 	MOVE_TARGET_WR_ERR,
138 	MOVE_TARGET_BITFLIPS,
139 	MOVE_RETRY,
140 };
141 
142 /*
143  * Return codes of the fastmap sub-system
144  *
145  * UBI_NO_FASTMAP: No fastmap super block was found
146  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
147  */
148 enum {
149 	UBI_NO_FASTMAP = 1,
150 	UBI_BAD_FASTMAP,
151 };
152 
153 /**
154  * struct ubi_wl_entry - wear-leveling entry.
155  * @u.rb: link in the corresponding (free/used) RB-tree
156  * @u.list: link in the protection queue
157  * @ec: erase counter
158  * @pnum: physical eraseblock number
159  *
160  * This data structure is used in the WL sub-system. Each physical eraseblock
161  * has a corresponding &struct wl_entry object which may be kept in different
162  * RB-trees. See WL sub-system for details.
163  */
164 struct ubi_wl_entry {
165 	union {
166 		struct rb_node rb;
167 		struct list_head list;
168 	} u;
169 	int ec;
170 	int pnum;
171 };
172 
173 /**
174  * struct ubi_ltree_entry - an entry in the lock tree.
175  * @rb: links RB-tree nodes
176  * @vol_id: volume ID of the locked logical eraseblock
177  * @lnum: locked logical eraseblock number
178  * @users: how many tasks are using this logical eraseblock or wait for it
179  * @mutex: read/write mutex to implement read/write access serialization to
180  *         the (@vol_id, @lnum) logical eraseblock
181  *
182  * This data structure is used in the EBA sub-system to implement per-LEB
183  * locking. When a logical eraseblock is being locked - corresponding
184  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
185  * See EBA sub-system for details.
186  */
187 struct ubi_ltree_entry {
188 	struct rb_node rb;
189 	int vol_id;
190 	int lnum;
191 	int users;
192 	struct rw_semaphore mutex;
193 };
194 
195 /**
196  * struct ubi_rename_entry - volume re-name description data structure.
197  * @new_name_len: new volume name length
198  * @new_name: new volume name
199  * @remove: if not zero, this volume should be removed, not re-named
200  * @desc: descriptor of the volume
201  * @list: links re-name entries into a list
202  *
203  * This data structure is utilized in the multiple volume re-name code. Namely,
204  * UBI first creates a list of &struct ubi_rename_entry objects from the
205  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
206  * the job.
207  */
208 struct ubi_rename_entry {
209 	int new_name_len;
210 	char new_name[UBI_VOL_NAME_MAX + 1];
211 	int remove;
212 	struct ubi_volume_desc *desc;
213 	struct list_head list;
214 };
215 
216 struct ubi_volume_desc;
217 
218 /**
219  * struct ubi_fastmap_layout - in-memory fastmap data structure.
220  * @e: PEBs used by the current fastmap
221  * @to_be_tortured: if non-zero tortured this PEB
222  * @used_blocks: number of used PEBs
223  * @max_pool_size: maximal size of the user pool
224  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
225  */
226 struct ubi_fastmap_layout {
227 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
228 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
229 	int used_blocks;
230 	int max_pool_size;
231 	int max_wl_pool_size;
232 };
233 
234 /**
235  * struct ubi_fm_pool - in-memory fastmap pool
236  * @pebs: PEBs in this pool
237  * @used: number of used PEBs
238  * @size: total number of PEBs in this pool
239  * @max_size: maximal size of the pool
240  *
241  * A pool gets filled with up to max_size.
242  * If all PEBs within the pool are used a new fastmap will be written
243  * to the flash and the pool gets refilled with empty PEBs.
244  *
245  */
246 struct ubi_fm_pool {
247 	int pebs[UBI_FM_MAX_POOL_SIZE];
248 	int used;
249 	int size;
250 	int max_size;
251 };
252 
253 /**
254  * struct ubi_volume - UBI volume description data structure.
255  * @dev: device object to make use of the the Linux device model
256  * @cdev: character device object to create character device
257  * @ubi: reference to the UBI device description object
258  * @vol_id: volume ID
259  * @ref_count: volume reference count
260  * @readers: number of users holding this volume in read-only mode
261  * @writers: number of users holding this volume in read-write mode
262  * @exclusive: whether somebody holds this volume in exclusive mode
263  *
264  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
265  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
266  * @usable_leb_size: logical eraseblock size without padding
267  * @used_ebs: how many logical eraseblocks in this volume contain data
268  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
269  * @used_bytes: how many bytes of data this volume contains
270  * @alignment: volume alignment
271  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
272  *            satisfy the requested alignment
273  * @name_len: volume name length
274  * @name: volume name
275  *
276  * @upd_ebs: how many eraseblocks are expected to be updated
277  * @ch_lnum: LEB number which is being changing by the atomic LEB change
278  *           operation
279  * @upd_bytes: how many bytes are expected to be received for volume update or
280  *             atomic LEB change
281  * @upd_received: how many bytes were already received for volume update or
282  *                atomic LEB change
283  * @upd_buf: update buffer which is used to collect update data or data for
284  *           atomic LEB change
285  *
286  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
287  * @checked: %1 if this static volume was checked
288  * @corrupted: %1 if the volume is corrupted (static volumes only)
289  * @upd_marker: %1 if the update marker is set for this volume
290  * @updating: %1 if the volume is being updated
291  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
292  * @direct_writes: %1 if direct writes are enabled for this volume
293  *
294  * The @corrupted field indicates that the volume's contents is corrupted.
295  * Since UBI protects only static volumes, this field is not relevant to
296  * dynamic volumes - it is user's responsibility to assure their data
297  * integrity.
298  *
299  * The @upd_marker flag indicates that this volume is either being updated at
300  * the moment or is damaged because of an unclean reboot.
301  */
302 struct ubi_volume {
303 	struct device dev;
304 	struct cdev cdev;
305 	struct ubi_device *ubi;
306 	int vol_id;
307 	int ref_count;
308 	int readers;
309 	int writers;
310 	int exclusive;
311 
312 	int reserved_pebs;
313 	int vol_type;
314 	int usable_leb_size;
315 	int used_ebs;
316 	int last_eb_bytes;
317 	long long used_bytes;
318 	int alignment;
319 	int data_pad;
320 	int name_len;
321 	char name[UBI_VOL_NAME_MAX + 1];
322 
323 	int upd_ebs;
324 	int ch_lnum;
325 	long long upd_bytes;
326 	long long upd_received;
327 	void *upd_buf;
328 
329 	int *eba_tbl;
330 	unsigned int checked:1;
331 	unsigned int corrupted:1;
332 	unsigned int upd_marker:1;
333 	unsigned int updating:1;
334 	unsigned int changing_leb:1;
335 	unsigned int direct_writes:1;
336 };
337 
338 /**
339  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
340  * @vol: reference to the corresponding volume description object
341  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
342  */
343 struct ubi_volume_desc {
344 	struct ubi_volume *vol;
345 	int mode;
346 };
347 
348 struct ubi_wl_entry;
349 
350 /**
351  * struct ubi_debug_info - debugging information for an UBI device.
352  *
353  * @chk_gen: if UBI general extra checks are enabled
354  * @chk_io: if UBI I/O extra checks are enabled
355  * @disable_bgt: disable the background task for testing purposes
356  * @emulate_bitflips: emulate bit-flips for testing purposes
357  * @emulate_io_failures: emulate write/erase failures for testing purposes
358  * @dfs_dir_name: name of debugfs directory containing files of this UBI device
359  * @dfs_dir: direntry object of the UBI device debugfs directory
360  * @dfs_chk_gen: debugfs knob to enable UBI general extra checks
361  * @dfs_chk_io: debugfs knob to enable UBI I/O extra checks
362  * @dfs_disable_bgt: debugfs knob to disable the background task
363  * @dfs_emulate_bitflips: debugfs knob to emulate bit-flips
364  * @dfs_emulate_io_failures: debugfs knob to emulate write/erase failures
365  */
366 struct ubi_debug_info {
367 	unsigned int chk_gen:1;
368 	unsigned int chk_io:1;
369 	unsigned int disable_bgt:1;
370 	unsigned int emulate_bitflips:1;
371 	unsigned int emulate_io_failures:1;
372 	char dfs_dir_name[UBI_DFS_DIR_LEN + 1];
373 	struct dentry *dfs_dir;
374 	struct dentry *dfs_chk_gen;
375 	struct dentry *dfs_chk_io;
376 	struct dentry *dfs_disable_bgt;
377 	struct dentry *dfs_emulate_bitflips;
378 	struct dentry *dfs_emulate_io_failures;
379 };
380 
381 /**
382  * struct ubi_device - UBI device description structure
383  * @dev: UBI device object to use the the Linux device model
384  * @cdev: character device object to create character device
385  * @ubi_num: UBI device number
386  * @ubi_name: UBI device name
387  * @vol_count: number of volumes in this UBI device
388  * @volumes: volumes of this UBI device
389  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
390  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
391  *                @vol->readers, @vol->writers, @vol->exclusive,
392  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
393  * @ref_count: count of references on the UBI device
394  * @image_seq: image sequence number recorded on EC headers
395  *
396  * @rsvd_pebs: count of reserved physical eraseblocks
397  * @avail_pebs: count of available physical eraseblocks
398  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
399  *                 handling
400  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
401  *
402  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
403  *                     of UBI initialization
404  * @vtbl_slots: how many slots are available in the volume table
405  * @vtbl_size: size of the volume table in bytes
406  * @vtbl: in-RAM volume table copy
407  * @device_mutex: protects on-flash volume table and serializes volume
408  *                creation, deletion, update, re-size, re-name and set
409  *                property
410  *
411  * @max_ec: current highest erase counter value
412  * @mean_ec: current mean erase counter value
413  *
414  * @global_sqnum: global sequence number
415  * @ltree_lock: protects the lock tree and @global_sqnum
416  * @ltree: the lock tree
417  * @alc_mutex: serializes "atomic LEB change" operations
418  *
419  * @fm_disabled: non-zero if fastmap is disabled (default)
420  * @fm: in-memory data structure of the currently used fastmap
421  * @fm_pool: in-memory data structure of the fastmap pool
422  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
423  *		sub-system
424  * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
425  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
426  * @fm_size: fastmap size in bytes
427  * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
428  * @fm_work: fastmap work queue
429  *
430  * @used: RB-tree of used physical eraseblocks
431  * @erroneous: RB-tree of erroneous used physical eraseblocks
432  * @free: RB-tree of free physical eraseblocks
433  * @free_count: Contains the number of elements in @free
434  * @scrub: RB-tree of physical eraseblocks which need scrubbing
435  * @pq: protection queue (contain physical eraseblocks which are temporarily
436  *      protected from the wear-leveling worker)
437  * @pq_head: protection queue head
438  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
439  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
440  *	     @erroneous, and @erroneous_peb_count fields
441  * @move_mutex: serializes eraseblock moves
442  * @work_sem: synchronizes the WL worker with use tasks
443  * @wl_scheduled: non-zero if the wear-leveling was scheduled
444  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
445  *             physical eraseblock
446  * @move_from: physical eraseblock from where the data is being moved
447  * @move_to: physical eraseblock where the data is being moved to
448  * @move_to_put: if the "to" PEB was put
449  * @works: list of pending works
450  * @works_count: count of pending works
451  * @bgt_thread: background thread description object
452  * @thread_enabled: if the background thread is enabled
453  * @bgt_name: background thread name
454  *
455  * @flash_size: underlying MTD device size (in bytes)
456  * @peb_count: count of physical eraseblocks on the MTD device
457  * @peb_size: physical eraseblock size
458  * @bad_peb_limit: top limit of expected bad physical eraseblocks
459  * @bad_peb_count: count of bad physical eraseblocks
460  * @good_peb_count: count of good physical eraseblocks
461  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
462  *                  used by UBI)
463  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
464  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
465  * @min_io_size: minimal input/output unit size of the underlying MTD device
466  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
467  * @ro_mode: if the UBI device is in read-only mode
468  * @leb_size: logical eraseblock size
469  * @leb_start: starting offset of logical eraseblocks within physical
470  *             eraseblocks
471  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
472  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
473  * @vid_hdr_offset: starting offset of the volume identifier header (might be
474  *                  unaligned)
475  * @vid_hdr_aloffset: starting offset of the VID header aligned to
476  * @hdrs_min_io_size
477  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
478  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
479  *               not
480  * @nor_flash: non-zero if working on top of NOR flash
481  * @max_write_size: maximum amount of bytes the underlying flash can write at a
482  *                  time (MTD write buffer size)
483  * @mtd: MTD device descriptor
484  *
485  * @peb_buf: a buffer of PEB size used for different purposes
486  * @buf_mutex: protects @peb_buf
487  * @ckvol_mutex: serializes static volume checking when opening
488  *
489  * @dbg: debugging information for this UBI device
490  */
491 struct ubi_device {
492 	struct cdev cdev;
493 	struct device dev;
494 	int ubi_num;
495 	char ubi_name[sizeof(UBI_NAME_STR)+5];
496 	int vol_count;
497 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
498 	spinlock_t volumes_lock;
499 	int ref_count;
500 	int image_seq;
501 
502 	int rsvd_pebs;
503 	int avail_pebs;
504 	int beb_rsvd_pebs;
505 	int beb_rsvd_level;
506 	int bad_peb_limit;
507 
508 	int autoresize_vol_id;
509 	int vtbl_slots;
510 	int vtbl_size;
511 	struct ubi_vtbl_record *vtbl;
512 	struct mutex device_mutex;
513 
514 	int max_ec;
515 	/* Note, mean_ec is not updated run-time - should be fixed */
516 	int mean_ec;
517 
518 	/* EBA sub-system's stuff */
519 	unsigned long long global_sqnum;
520 	spinlock_t ltree_lock;
521 	struct rb_root ltree;
522 	struct mutex alc_mutex;
523 
524 	/* Fastmap stuff */
525 	int fm_disabled;
526 	struct ubi_fastmap_layout *fm;
527 	struct ubi_fm_pool fm_pool;
528 	struct ubi_fm_pool fm_wl_pool;
529 	struct rw_semaphore fm_sem;
530 	struct mutex fm_mutex;
531 	void *fm_buf;
532 	size_t fm_size;
533 	struct work_struct fm_work;
534 
535 	/* Wear-leveling sub-system's stuff */
536 	struct rb_root used;
537 	struct rb_root erroneous;
538 	struct rb_root free;
539 	int free_count;
540 	struct rb_root scrub;
541 	struct list_head pq[UBI_PROT_QUEUE_LEN];
542 	int pq_head;
543 	spinlock_t wl_lock;
544 	struct mutex move_mutex;
545 	struct rw_semaphore work_sem;
546 	int wl_scheduled;
547 	struct ubi_wl_entry **lookuptbl;
548 	struct ubi_wl_entry *move_from;
549 	struct ubi_wl_entry *move_to;
550 	int move_to_put;
551 	struct list_head works;
552 	int works_count;
553 	struct task_struct *bgt_thread;
554 	int thread_enabled;
555 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
556 
557 	/* I/O sub-system's stuff */
558 	long long flash_size;
559 	int peb_count;
560 	int peb_size;
561 	int bad_peb_count;
562 	int good_peb_count;
563 	int corr_peb_count;
564 	int erroneous_peb_count;
565 	int max_erroneous;
566 	int min_io_size;
567 	int hdrs_min_io_size;
568 	int ro_mode;
569 	int leb_size;
570 	int leb_start;
571 	int ec_hdr_alsize;
572 	int vid_hdr_alsize;
573 	int vid_hdr_offset;
574 	int vid_hdr_aloffset;
575 	int vid_hdr_shift;
576 	unsigned int bad_allowed:1;
577 	unsigned int nor_flash:1;
578 	int max_write_size;
579 	struct mtd_info *mtd;
580 
581 	void *peb_buf;
582 	struct mutex buf_mutex;
583 	struct mutex ckvol_mutex;
584 
585 	struct ubi_debug_info dbg;
586 };
587 
588 /**
589  * struct ubi_ainf_peb - attach information about a physical eraseblock.
590  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
591  * @pnum: physical eraseblock number
592  * @vol_id: ID of the volume this LEB belongs to
593  * @lnum: logical eraseblock number
594  * @scrub: if this physical eraseblock needs scrubbing
595  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
596  * @sqnum: sequence number
597  * @u: unions RB-tree or @list links
598  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
599  * @u.list: link in one of the eraseblock lists
600  *
601  * One object of this type is allocated for each physical eraseblock when
602  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
603  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
604  */
605 struct ubi_ainf_peb {
606 	int ec;
607 	int pnum;
608 	int vol_id;
609 	int lnum;
610 	unsigned int scrub:1;
611 	unsigned int copy_flag:1;
612 	unsigned long long sqnum;
613 	union {
614 		struct rb_node rb;
615 		struct list_head list;
616 	} u;
617 };
618 
619 /**
620  * struct ubi_ainf_volume - attaching information about a volume.
621  * @vol_id: volume ID
622  * @highest_lnum: highest logical eraseblock number in this volume
623  * @leb_count: number of logical eraseblocks in this volume
624  * @vol_type: volume type
625  * @used_ebs: number of used logical eraseblocks in this volume (only for
626  *            static volumes)
627  * @last_data_size: amount of data in the last logical eraseblock of this
628  *                  volume (always equivalent to the usable logical eraseblock
629  *                  size in case of dynamic volumes)
630  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
631  *            are not used (due to volume alignment)
632  * @compat: compatibility flags of this volume
633  * @rb: link in the volume RB-tree
634  * @root: root of the RB-tree containing all the eraseblock belonging to this
635  *        volume (&struct ubi_ainf_peb objects)
636  *
637  * One object of this type is allocated for each volume when attaching an MTD
638  * device.
639  */
640 struct ubi_ainf_volume {
641 	int vol_id;
642 	int highest_lnum;
643 	int leb_count;
644 	int vol_type;
645 	int used_ebs;
646 	int last_data_size;
647 	int data_pad;
648 	int compat;
649 	struct rb_node rb;
650 	struct rb_root root;
651 };
652 
653 /**
654  * struct ubi_attach_info - MTD device attaching information.
655  * @volumes: root of the volume RB-tree
656  * @corr: list of corrupted physical eraseblocks
657  * @free: list of free physical eraseblocks
658  * @erase: list of physical eraseblocks which have to be erased
659  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
660  *         those belonging to "preserve"-compatible internal volumes)
661  * @corr_peb_count: count of PEBs in the @corr list
662  * @empty_peb_count: count of PEBs which are presumably empty (contain only
663  *                   0xFF bytes)
664  * @alien_peb_count: count of PEBs in the @alien list
665  * @bad_peb_count: count of bad physical eraseblocks
666  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
667  *                       as bad yet, but which look like bad
668  * @vols_found: number of volumes found
669  * @highest_vol_id: highest volume ID
670  * @is_empty: flag indicating whether the MTD device is empty or not
671  * @min_ec: lowest erase counter value
672  * @max_ec: highest erase counter value
673  * @max_sqnum: highest sequence number value
674  * @mean_ec: mean erase counter value
675  * @ec_sum: a temporary variable used when calculating @mean_ec
676  * @ec_count: a temporary variable used when calculating @mean_ec
677  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
678  *
679  * This data structure contains the result of attaching an MTD device and may
680  * be used by other UBI sub-systems to build final UBI data structures, further
681  * error-recovery and so on.
682  */
683 struct ubi_attach_info {
684 	struct rb_root volumes;
685 	struct list_head corr;
686 	struct list_head free;
687 	struct list_head erase;
688 	struct list_head alien;
689 	int corr_peb_count;
690 	int empty_peb_count;
691 	int alien_peb_count;
692 	int bad_peb_count;
693 	int maybe_bad_peb_count;
694 	int vols_found;
695 	int highest_vol_id;
696 	int is_empty;
697 	int min_ec;
698 	int max_ec;
699 	unsigned long long max_sqnum;
700 	int mean_ec;
701 	uint64_t ec_sum;
702 	int ec_count;
703 	struct kmem_cache *aeb_slab_cache;
704 };
705 
706 /**
707  * struct ubi_work - UBI work description data structure.
708  * @list: a link in the list of pending works
709  * @func: worker function
710  * @e: physical eraseblock to erase
711  * @vol_id: the volume ID on which this erasure is being performed
712  * @lnum: the logical eraseblock number
713  * @torture: if the physical eraseblock has to be tortured
714  * @anchor: produce a anchor PEB to by used by fastmap
715  *
716  * The @func pointer points to the worker function. If the @cancel argument is
717  * not zero, the worker has to free the resources and exit immediately. The
718  * worker has to return zero in case of success and a negative error code in
719  * case of failure.
720  */
721 struct ubi_work {
722 	struct list_head list;
723 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
724 	/* The below fields are only relevant to erasure works */
725 	struct ubi_wl_entry *e;
726 	int vol_id;
727 	int lnum;
728 	int torture;
729 	int anchor;
730 };
731 
732 #include "debug.h"
733 
734 extern struct kmem_cache *ubi_wl_entry_slab;
735 extern const struct file_operations ubi_ctrl_cdev_operations;
736 extern const struct file_operations ubi_cdev_operations;
737 extern const struct file_operations ubi_vol_cdev_operations;
738 extern struct class *ubi_class;
739 extern struct mutex ubi_devices_mutex;
740 extern struct blocking_notifier_head ubi_notifiers;
741 
742 /* attach.c */
743 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
744 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
745 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
746 				    int vol_id);
747 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
748 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
749 				       struct ubi_attach_info *ai);
750 int ubi_attach(struct ubi_device *ubi, int force_scan);
751 void ubi_destroy_ai(struct ubi_attach_info *ai);
752 
753 /* vtbl.c */
754 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
755 			   struct ubi_vtbl_record *vtbl_rec);
756 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
757 			    struct list_head *rename_list);
758 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
759 
760 /* vmt.c */
761 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
762 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
763 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
764 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
765 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
766 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
767 
768 /* upd.c */
769 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
770 		     long long bytes);
771 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
772 			 const void __user *buf, int count);
773 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
774 			 const struct ubi_leb_change_req *req);
775 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
776 			     const void __user *buf, int count);
777 
778 /* misc.c */
779 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
780 		      int length);
781 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
782 void ubi_update_reserved(struct ubi_device *ubi);
783 void ubi_calculate_reserved(struct ubi_device *ubi);
784 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
785 
786 /* eba.c */
787 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
788 		      int lnum);
789 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
790 		     void *buf, int offset, int len, int check);
791 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
792 		      const void *buf, int offset, int len);
793 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
794 			 int lnum, const void *buf, int len, int used_ebs);
795 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
796 			      int lnum, const void *buf, int len);
797 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
798 		     struct ubi_vid_hdr *vid_hdr);
799 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
800 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
801 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
802 		   struct ubi_attach_info *ai_scan);
803 
804 /* wl.c */
805 int ubi_wl_get_peb(struct ubi_device *ubi);
806 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
807 		   int pnum, int torture);
808 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
809 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
810 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
811 void ubi_wl_close(struct ubi_device *ubi);
812 int ubi_thread(void *u);
813 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
814 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
815 		      int lnum, int torture);
816 int ubi_is_erase_work(struct ubi_work *wrk);
817 void ubi_refill_pools(struct ubi_device *ubi);
818 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
819 
820 /* io.c */
821 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
822 		int len);
823 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
824 		 int len);
825 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
826 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
827 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
828 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
829 		       struct ubi_ec_hdr *ec_hdr, int verbose);
830 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
831 			struct ubi_ec_hdr *ec_hdr);
832 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
833 			struct ubi_vid_hdr *vid_hdr, int verbose);
834 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
835 			 struct ubi_vid_hdr *vid_hdr);
836 
837 /* build.c */
838 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
839 		       int vid_hdr_offset, int max_beb_per1024);
840 int ubi_detach_mtd_dev(int ubi_num, int anyway);
841 struct ubi_device *ubi_get_device(int ubi_num);
842 void ubi_put_device(struct ubi_device *ubi);
843 struct ubi_device *ubi_get_by_major(int major);
844 int ubi_major2num(int major);
845 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
846 		      int ntype);
847 int ubi_notify_all(struct ubi_device *ubi, int ntype,
848 		   struct notifier_block *nb);
849 int ubi_enumerate_volumes(struct notifier_block *nb);
850 void ubi_free_internal_volumes(struct ubi_device *ubi);
851 
852 /* kapi.c */
853 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
854 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
855 			    struct ubi_volume_info *vi);
856 /* scan.c */
857 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
858 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
859 
860 /* fastmap.c */
861 size_t ubi_calc_fm_size(struct ubi_device *ubi);
862 int ubi_update_fastmap(struct ubi_device *ubi);
863 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
864 		     int fm_anchor);
865 
866 /* block.c */
867 #ifdef CONFIG_MTD_UBI_BLOCK
868 int ubiblock_init(void);
869 void ubiblock_exit(void);
870 int ubiblock_create(struct ubi_volume_info *vi);
871 int ubiblock_remove(struct ubi_volume_info *vi);
872 #else
873 static inline int ubiblock_init(void) { return 0; }
874 static inline void ubiblock_exit(void) {}
875 static inline int ubiblock_create(struct ubi_volume_info *vi)
876 {
877 	return -ENOSYS;
878 }
879 static inline int ubiblock_remove(struct ubi_volume_info *vi)
880 {
881 	return -ENOSYS;
882 }
883 #endif
884 
885 
886 /*
887  * ubi_rb_for_each_entry - walk an RB-tree.
888  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
889  * @pos: a pointer to RB-tree entry type to use as a loop counter
890  * @root: RB-tree's root
891  * @member: the name of the 'struct rb_node' within the RB-tree entry
892  */
893 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
894 	for (rb = rb_first(root),                                            \
895 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
896 	     rb;                                                             \
897 	     rb = rb_next(rb),                                               \
898 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
899 
900 /*
901  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
902  *
903  * @av: volume attaching information
904  * @aeb: attaching eraseblock information
905  * @list: the list to move to
906  */
907 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
908 					 struct ubi_ainf_peb *aeb,
909 					 struct list_head *list)
910 {
911 		rb_erase(&aeb->u.rb, &av->root);
912 		list_add_tail(&aeb->u.list, list);
913 }
914 
915 /**
916  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
917  * @ubi: UBI device description object
918  * @gfp_flags: GFP flags to allocate with
919  *
920  * This function returns a pointer to the newly allocated and zero-filled
921  * volume identifier header object in case of success and %NULL in case of
922  * failure.
923  */
924 static inline struct ubi_vid_hdr *
925 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
926 {
927 	void *vid_hdr;
928 
929 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
930 	if (!vid_hdr)
931 		return NULL;
932 
933 	/*
934 	 * VID headers may be stored at un-aligned flash offsets, so we shift
935 	 * the pointer.
936 	 */
937 	return vid_hdr + ubi->vid_hdr_shift;
938 }
939 
940 /**
941  * ubi_free_vid_hdr - free a volume identifier header object.
942  * @ubi: UBI device description object
943  * @vid_hdr: the object to free
944  */
945 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
946 				    struct ubi_vid_hdr *vid_hdr)
947 {
948 	void *p = vid_hdr;
949 
950 	if (!p)
951 		return;
952 
953 	kfree(p - ubi->vid_hdr_shift);
954 }
955 
956 /*
957  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
958  * the beginning of the logical eraseblock, not to the beginning of the
959  * physical eraseblock.
960  */
961 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
962 				   int pnum, int offset, int len)
963 {
964 	ubi_assert(offset >= 0);
965 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
966 }
967 
968 /*
969  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
970  * the beginning of the logical eraseblock, not to the beginning of the
971  * physical eraseblock.
972  */
973 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
974 				    int pnum, int offset, int len)
975 {
976 	ubi_assert(offset >= 0);
977 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
978 }
979 
980 /**
981  * ubi_ro_mode - switch to read-only mode.
982  * @ubi: UBI device description object
983  */
984 static inline void ubi_ro_mode(struct ubi_device *ubi)
985 {
986 	if (!ubi->ro_mode) {
987 		ubi->ro_mode = 1;
988 		ubi_warn("switch to read-only mode");
989 		dump_stack();
990 	}
991 }
992 
993 /**
994  * vol_id2idx - get table index by volume ID.
995  * @ubi: UBI device description object
996  * @vol_id: volume ID
997  */
998 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
999 {
1000 	if (vol_id >= UBI_INTERNAL_VOL_START)
1001 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1002 	else
1003 		return vol_id;
1004 }
1005 
1006 /**
1007  * idx2vol_id - get volume ID by table index.
1008  * @ubi: UBI device description object
1009  * @idx: table index
1010  */
1011 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1012 {
1013 	if (idx >= ubi->vtbl_slots)
1014 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1015 	else
1016 		return idx;
1017 }
1018 
1019 #endif /* !__UBI_UBI_H__ */
1020