xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 6774def6)
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: used to wait for all the scheduled works to finish and prevent
443  * new works from being submitted
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 	struct work_struct fm_work;
535 
536 	/* Wear-leveling sub-system's stuff */
537 	struct rb_root used;
538 	struct rb_root erroneous;
539 	struct rb_root free;
540 	int free_count;
541 	struct rb_root scrub;
542 	struct list_head pq[UBI_PROT_QUEUE_LEN];
543 	int pq_head;
544 	spinlock_t wl_lock;
545 	struct mutex move_mutex;
546 	struct rw_semaphore work_sem;
547 	int wl_scheduled;
548 	struct ubi_wl_entry **lookuptbl;
549 	struct ubi_wl_entry *move_from;
550 	struct ubi_wl_entry *move_to;
551 	int move_to_put;
552 	struct list_head works;
553 	int works_count;
554 	struct task_struct *bgt_thread;
555 	int thread_enabled;
556 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
557 
558 	/* I/O sub-system's stuff */
559 	long long flash_size;
560 	int peb_count;
561 	int peb_size;
562 	int bad_peb_count;
563 	int good_peb_count;
564 	int corr_peb_count;
565 	int erroneous_peb_count;
566 	int max_erroneous;
567 	int min_io_size;
568 	int hdrs_min_io_size;
569 	int ro_mode;
570 	int leb_size;
571 	int leb_start;
572 	int ec_hdr_alsize;
573 	int vid_hdr_alsize;
574 	int vid_hdr_offset;
575 	int vid_hdr_aloffset;
576 	int vid_hdr_shift;
577 	unsigned int bad_allowed:1;
578 	unsigned int nor_flash:1;
579 	int max_write_size;
580 	struct mtd_info *mtd;
581 
582 	void *peb_buf;
583 	struct mutex buf_mutex;
584 	struct mutex ckvol_mutex;
585 
586 	struct ubi_debug_info dbg;
587 };
588 
589 /**
590  * struct ubi_ainf_peb - attach information about a physical eraseblock.
591  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
592  * @pnum: physical eraseblock number
593  * @vol_id: ID of the volume this LEB belongs to
594  * @lnum: logical eraseblock number
595  * @scrub: if this physical eraseblock needs scrubbing
596  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
597  * @sqnum: sequence number
598  * @u: unions RB-tree or @list links
599  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
600  * @u.list: link in one of the eraseblock lists
601  *
602  * One object of this type is allocated for each physical eraseblock when
603  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
604  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
605  */
606 struct ubi_ainf_peb {
607 	int ec;
608 	int pnum;
609 	int vol_id;
610 	int lnum;
611 	unsigned int scrub:1;
612 	unsigned int copy_flag:1;
613 	unsigned long long sqnum;
614 	union {
615 		struct rb_node rb;
616 		struct list_head list;
617 	} u;
618 };
619 
620 /**
621  * struct ubi_ainf_volume - attaching information about a volume.
622  * @vol_id: volume ID
623  * @highest_lnum: highest logical eraseblock number in this volume
624  * @leb_count: number of logical eraseblocks in this volume
625  * @vol_type: volume type
626  * @used_ebs: number of used logical eraseblocks in this volume (only for
627  *            static volumes)
628  * @last_data_size: amount of data in the last logical eraseblock of this
629  *                  volume (always equivalent to the usable logical eraseblock
630  *                  size in case of dynamic volumes)
631  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
632  *            are not used (due to volume alignment)
633  * @compat: compatibility flags of this volume
634  * @rb: link in the volume RB-tree
635  * @root: root of the RB-tree containing all the eraseblock belonging to this
636  *        volume (&struct ubi_ainf_peb objects)
637  *
638  * One object of this type is allocated for each volume when attaching an MTD
639  * device.
640  */
641 struct ubi_ainf_volume {
642 	int vol_id;
643 	int highest_lnum;
644 	int leb_count;
645 	int vol_type;
646 	int used_ebs;
647 	int last_data_size;
648 	int data_pad;
649 	int compat;
650 	struct rb_node rb;
651 	struct rb_root root;
652 };
653 
654 /**
655  * struct ubi_attach_info - MTD device attaching information.
656  * @volumes: root of the volume RB-tree
657  * @corr: list of corrupted physical eraseblocks
658  * @free: list of free physical eraseblocks
659  * @erase: list of physical eraseblocks which have to be erased
660  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
661  *         those belonging to "preserve"-compatible internal volumes)
662  * @corr_peb_count: count of PEBs in the @corr list
663  * @empty_peb_count: count of PEBs which are presumably empty (contain only
664  *                   0xFF bytes)
665  * @alien_peb_count: count of PEBs in the @alien list
666  * @bad_peb_count: count of bad physical eraseblocks
667  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
668  *                       as bad yet, but which look like bad
669  * @vols_found: number of volumes found
670  * @highest_vol_id: highest volume ID
671  * @is_empty: flag indicating whether the MTD device is empty or not
672  * @min_ec: lowest erase counter value
673  * @max_ec: highest erase counter value
674  * @max_sqnum: highest sequence number value
675  * @mean_ec: mean erase counter value
676  * @ec_sum: a temporary variable used when calculating @mean_ec
677  * @ec_count: a temporary variable used when calculating @mean_ec
678  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
679  *
680  * This data structure contains the result of attaching an MTD device and may
681  * be used by other UBI sub-systems to build final UBI data structures, further
682  * error-recovery and so on.
683  */
684 struct ubi_attach_info {
685 	struct rb_root volumes;
686 	struct list_head corr;
687 	struct list_head free;
688 	struct list_head erase;
689 	struct list_head alien;
690 	int corr_peb_count;
691 	int empty_peb_count;
692 	int alien_peb_count;
693 	int bad_peb_count;
694 	int maybe_bad_peb_count;
695 	int vols_found;
696 	int highest_vol_id;
697 	int is_empty;
698 	int min_ec;
699 	int max_ec;
700 	unsigned long long max_sqnum;
701 	int mean_ec;
702 	uint64_t ec_sum;
703 	int ec_count;
704 	struct kmem_cache *aeb_slab_cache;
705 };
706 
707 /**
708  * struct ubi_work - UBI work description data structure.
709  * @list: a link in the list of pending works
710  * @func: worker function
711  * @e: physical eraseblock to erase
712  * @vol_id: the volume ID on which this erasure is being performed
713  * @lnum: the logical eraseblock number
714  * @torture: if the physical eraseblock has to be tortured
715  * @anchor: produce a anchor PEB to by used by fastmap
716  *
717  * The @func pointer points to the worker function. If the @shutdown argument is
718  * not zero, the worker has to free the resources and exit immediately as the
719  * WL sub-system is shutting down.
720  * The worker has to return zero in case of success and a negative error code in
721  * case of failure.
722  */
723 struct ubi_work {
724 	struct list_head list;
725 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int shutdown);
726 	/* The below fields are only relevant to erasure works */
727 	struct ubi_wl_entry *e;
728 	int vol_id;
729 	int lnum;
730 	int torture;
731 	int anchor;
732 };
733 
734 #include "debug.h"
735 
736 extern struct kmem_cache *ubi_wl_entry_slab;
737 extern const struct file_operations ubi_ctrl_cdev_operations;
738 extern const struct file_operations ubi_cdev_operations;
739 extern const struct file_operations ubi_vol_cdev_operations;
740 extern struct class *ubi_class;
741 extern struct mutex ubi_devices_mutex;
742 extern struct blocking_notifier_head ubi_notifiers;
743 
744 /* attach.c */
745 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
746 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
747 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
748 				    int vol_id);
749 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
750 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
751 				       struct ubi_attach_info *ai);
752 int ubi_attach(struct ubi_device *ubi, int force_scan);
753 void ubi_destroy_ai(struct ubi_attach_info *ai);
754 
755 /* vtbl.c */
756 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
757 			   struct ubi_vtbl_record *vtbl_rec);
758 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
759 			    struct list_head *rename_list);
760 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
761 
762 /* vmt.c */
763 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
764 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
765 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
766 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
767 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
768 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
769 
770 /* upd.c */
771 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
772 		     long long bytes);
773 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
774 			 const void __user *buf, int count);
775 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
776 			 const struct ubi_leb_change_req *req);
777 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
778 			     const void __user *buf, int count);
779 
780 /* misc.c */
781 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
782 		      int length);
783 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
784 void ubi_update_reserved(struct ubi_device *ubi);
785 void ubi_calculate_reserved(struct ubi_device *ubi);
786 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
787 
788 /* eba.c */
789 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
790 		      int lnum);
791 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
792 		     void *buf, int offset, int len, int check);
793 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
794 		      const void *buf, int offset, int len);
795 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
796 			 int lnum, const void *buf, int len, int used_ebs);
797 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
798 			      int lnum, const void *buf, int len);
799 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
800 		     struct ubi_vid_hdr *vid_hdr);
801 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
802 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
803 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
804 		   struct ubi_attach_info *ai_scan);
805 
806 /* wl.c */
807 int ubi_wl_get_peb(struct ubi_device *ubi);
808 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
809 		   int pnum, int torture);
810 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
811 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
812 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
813 void ubi_wl_close(struct ubi_device *ubi);
814 int ubi_thread(void *u);
815 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
816 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
817 		      int lnum, int torture);
818 int ubi_is_erase_work(struct ubi_work *wrk);
819 void ubi_refill_pools(struct ubi_device *ubi);
820 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
821 
822 /* io.c */
823 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
824 		int len);
825 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
826 		 int len);
827 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
828 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
829 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
830 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
831 		       struct ubi_ec_hdr *ec_hdr, int verbose);
832 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
833 			struct ubi_ec_hdr *ec_hdr);
834 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
835 			struct ubi_vid_hdr *vid_hdr, int verbose);
836 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
837 			 struct ubi_vid_hdr *vid_hdr);
838 
839 /* build.c */
840 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
841 		       int vid_hdr_offset, int max_beb_per1024);
842 int ubi_detach_mtd_dev(int ubi_num, int anyway);
843 struct ubi_device *ubi_get_device(int ubi_num);
844 void ubi_put_device(struct ubi_device *ubi);
845 struct ubi_device *ubi_get_by_major(int major);
846 int ubi_major2num(int major);
847 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
848 		      int ntype);
849 int ubi_notify_all(struct ubi_device *ubi, int ntype,
850 		   struct notifier_block *nb);
851 int ubi_enumerate_volumes(struct notifier_block *nb);
852 void ubi_free_internal_volumes(struct ubi_device *ubi);
853 
854 /* kapi.c */
855 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
856 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
857 			    struct ubi_volume_info *vi);
858 /* scan.c */
859 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
860 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
861 
862 /* fastmap.c */
863 size_t ubi_calc_fm_size(struct ubi_device *ubi);
864 int ubi_update_fastmap(struct ubi_device *ubi);
865 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
866 		     int fm_anchor);
867 
868 /* block.c */
869 #ifdef CONFIG_MTD_UBI_BLOCK
870 int ubiblock_init(void);
871 void ubiblock_exit(void);
872 int ubiblock_create(struct ubi_volume_info *vi);
873 int ubiblock_remove(struct ubi_volume_info *vi);
874 #else
875 static inline int ubiblock_init(void) { return 0; }
876 static inline void ubiblock_exit(void) {}
877 static inline int ubiblock_create(struct ubi_volume_info *vi)
878 {
879 	return -ENOSYS;
880 }
881 static inline int ubiblock_remove(struct ubi_volume_info *vi)
882 {
883 	return -ENOSYS;
884 }
885 #endif
886 
887 
888 /*
889  * ubi_rb_for_each_entry - walk an RB-tree.
890  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
891  * @pos: a pointer to RB-tree entry type to use as a loop counter
892  * @root: RB-tree's root
893  * @member: the name of the 'struct rb_node' within the RB-tree entry
894  */
895 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
896 	for (rb = rb_first(root),                                            \
897 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
898 	     rb;                                                             \
899 	     rb = rb_next(rb),                                               \
900 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
901 
902 /*
903  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
904  *
905  * @av: volume attaching information
906  * @aeb: attaching eraseblock information
907  * @list: the list to move to
908  */
909 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
910 					 struct ubi_ainf_peb *aeb,
911 					 struct list_head *list)
912 {
913 		rb_erase(&aeb->u.rb, &av->root);
914 		list_add_tail(&aeb->u.list, list);
915 }
916 
917 /**
918  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
919  * @ubi: UBI device description object
920  * @gfp_flags: GFP flags to allocate with
921  *
922  * This function returns a pointer to the newly allocated and zero-filled
923  * volume identifier header object in case of success and %NULL in case of
924  * failure.
925  */
926 static inline struct ubi_vid_hdr *
927 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
928 {
929 	void *vid_hdr;
930 
931 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
932 	if (!vid_hdr)
933 		return NULL;
934 
935 	/*
936 	 * VID headers may be stored at un-aligned flash offsets, so we shift
937 	 * the pointer.
938 	 */
939 	return vid_hdr + ubi->vid_hdr_shift;
940 }
941 
942 /**
943  * ubi_free_vid_hdr - free a volume identifier header object.
944  * @ubi: UBI device description object
945  * @vid_hdr: the object to free
946  */
947 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
948 				    struct ubi_vid_hdr *vid_hdr)
949 {
950 	void *p = vid_hdr;
951 
952 	if (!p)
953 		return;
954 
955 	kfree(p - ubi->vid_hdr_shift);
956 }
957 
958 /*
959  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
960  * the beginning of the logical eraseblock, not to the beginning of the
961  * physical eraseblock.
962  */
963 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
964 				   int pnum, int offset, int len)
965 {
966 	ubi_assert(offset >= 0);
967 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
968 }
969 
970 /*
971  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
972  * the beginning of the logical eraseblock, not to the beginning of the
973  * physical eraseblock.
974  */
975 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
976 				    int pnum, int offset, int len)
977 {
978 	ubi_assert(offset >= 0);
979 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
980 }
981 
982 /**
983  * ubi_ro_mode - switch to read-only mode.
984  * @ubi: UBI device description object
985  */
986 static inline void ubi_ro_mode(struct ubi_device *ubi)
987 {
988 	if (!ubi->ro_mode) {
989 		ubi->ro_mode = 1;
990 		ubi_warn("switch to read-only mode");
991 		dump_stack();
992 	}
993 }
994 
995 /**
996  * vol_id2idx - get table index by volume ID.
997  * @ubi: UBI device description object
998  * @vol_id: volume ID
999  */
1000 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
1001 {
1002 	if (vol_id >= UBI_INTERNAL_VOL_START)
1003 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
1004 	else
1005 		return vol_id;
1006 }
1007 
1008 /**
1009  * idx2vol_id - get volume ID by table index.
1010  * @ubi: UBI device description object
1011  * @idx: table index
1012  */
1013 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
1014 {
1015 	if (idx >= ubi->vtbl_slots)
1016 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
1017 	else
1018 		return idx;
1019 }
1020 
1021 #endif /* !__UBI_UBI_H__ */
1022