xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 05bcf503)
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/init.h>
26 #include <linux/types.h>
27 #include <linux/list.h>
28 #include <linux/rbtree.h>
29 #include <linux/sched.h>
30 #include <linux/wait.h>
31 #include <linux/mutex.h>
32 #include <linux/rwsem.h>
33 #include <linux/spinlock.h>
34 #include <linux/fs.h>
35 #include <linux/cdev.h>
36 #include <linux/device.h>
37 #include <linux/slab.h>
38 #include <linux/string.h>
39 #include <linux/vmalloc.h>
40 #include <linux/notifier.h>
41 #include <linux/mtd/mtd.h>
42 #include <linux/mtd/ubi.h>
43 #include <asm/pgtable.h>
44 
45 #include "ubi-media.h"
46 
47 /* Maximum number of supported UBI devices */
48 #define UBI_MAX_DEVICES 32
49 
50 /* UBI name used for character devices, sysfs, etc */
51 #define UBI_NAME_STR "ubi"
52 
53 /* Normal UBI messages */
54 #define ubi_msg(fmt, ...) pr_notice("UBI: " fmt "\n", ##__VA_ARGS__)
55 /* UBI warning messages */
56 #define ubi_warn(fmt, ...) pr_warn("UBI warning: %s: " fmt "\n",  \
57 				   __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(fmt, ...) pr_err("UBI error: %s: " fmt "\n",      \
60 				 __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  * Error codes returned by the I/O sub-system.
89  *
90  * UBI_IO_FF: the read region of flash contains only 0xFFs
91  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
92  *                     integrity error reported by the MTD driver
93  *                     (uncorrectable ECC error in case of NAND)
94  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
95  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
96  *                         data integrity error reported by the MTD driver
97  *                         (uncorrectable ECC error in case of NAND)
98  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
99  *
100  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
101  * be or'ed with other error code. But this is a big change because there are
102  * may callers, so it does not worth the risk of introducing a bug
103  */
104 enum {
105 	UBI_IO_FF = 1,
106 	UBI_IO_FF_BITFLIPS,
107 	UBI_IO_BAD_HDR,
108 	UBI_IO_BAD_HDR_EBADMSG,
109 	UBI_IO_BITFLIPS,
110 };
111 
112 /*
113  * Return codes of the 'ubi_eba_copy_leb()' function.
114  *
115  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
116  *                   PEB was put meanwhile, or there is I/O on the source PEB
117  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
118  *                     PEB
119  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
120  *                     PEB
121  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
122  *                     PEB
123  * MOVE_TARGET_BITFLIPS: canceled because a bit-flip was detected in the
124  *                       target PEB
125  * MOVE_RETRY: retry scrubbing the PEB
126  */
127 enum {
128 	MOVE_CANCEL_RACE = 1,
129 	MOVE_SOURCE_RD_ERR,
130 	MOVE_TARGET_RD_ERR,
131 	MOVE_TARGET_WR_ERR,
132 	MOVE_TARGET_BITFLIPS,
133 	MOVE_RETRY,
134 };
135 
136 /*
137  * Return codes of the fastmap sub-system
138  *
139  * UBI_NO_FASTMAP: No fastmap super block was found
140  * UBI_BAD_FASTMAP: A fastmap was found but it's unusable
141  */
142 enum {
143 	UBI_NO_FASTMAP = 1,
144 	UBI_BAD_FASTMAP,
145 };
146 
147 /**
148  * struct ubi_wl_entry - wear-leveling entry.
149  * @u.rb: link in the corresponding (free/used) RB-tree
150  * @u.list: link in the protection queue
151  * @ec: erase counter
152  * @pnum: physical eraseblock number
153  *
154  * This data structure is used in the WL sub-system. Each physical eraseblock
155  * has a corresponding &struct wl_entry object which may be kept in different
156  * RB-trees. See WL sub-system for details.
157  */
158 struct ubi_wl_entry {
159 	union {
160 		struct rb_node rb;
161 		struct list_head list;
162 	} u;
163 	int ec;
164 	int pnum;
165 };
166 
167 /**
168  * struct ubi_ltree_entry - an entry in the lock tree.
169  * @rb: links RB-tree nodes
170  * @vol_id: volume ID of the locked logical eraseblock
171  * @lnum: locked logical eraseblock number
172  * @users: how many tasks are using this logical eraseblock or wait for it
173  * @mutex: read/write mutex to implement read/write access serialization to
174  *         the (@vol_id, @lnum) logical eraseblock
175  *
176  * This data structure is used in the EBA sub-system to implement per-LEB
177  * locking. When a logical eraseblock is being locked - corresponding
178  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
179  * See EBA sub-system for details.
180  */
181 struct ubi_ltree_entry {
182 	struct rb_node rb;
183 	int vol_id;
184 	int lnum;
185 	int users;
186 	struct rw_semaphore mutex;
187 };
188 
189 /**
190  * struct ubi_rename_entry - volume re-name description data structure.
191  * @new_name_len: new volume name length
192  * @new_name: new volume name
193  * @remove: if not zero, this volume should be removed, not re-named
194  * @desc: descriptor of the volume
195  * @list: links re-name entries into a list
196  *
197  * This data structure is utilized in the multiple volume re-name code. Namely,
198  * UBI first creates a list of &struct ubi_rename_entry objects from the
199  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
200  * the job.
201  */
202 struct ubi_rename_entry {
203 	int new_name_len;
204 	char new_name[UBI_VOL_NAME_MAX + 1];
205 	int remove;
206 	struct ubi_volume_desc *desc;
207 	struct list_head list;
208 };
209 
210 struct ubi_volume_desc;
211 
212 /**
213  * struct ubi_fastmap_layout - in-memory fastmap data structure.
214  * @e: PEBs used by the current fastmap
215  * @to_be_tortured: if non-zero tortured this PEB
216  * @used_blocks: number of used PEBs
217  * @max_pool_size: maximal size of the user pool
218  * @max_wl_pool_size: maximal size of the pool used by the WL sub-system
219  */
220 struct ubi_fastmap_layout {
221 	struct ubi_wl_entry *e[UBI_FM_MAX_BLOCKS];
222 	int to_be_tortured[UBI_FM_MAX_BLOCKS];
223 	int used_blocks;
224 	int max_pool_size;
225 	int max_wl_pool_size;
226 };
227 
228 /**
229  * struct ubi_fm_pool - in-memory fastmap pool
230  * @pebs: PEBs in this pool
231  * @used: number of used PEBs
232  * @size: total number of PEBs in this pool
233  * @max_size: maximal size of the pool
234  *
235  * A pool gets filled with up to max_size.
236  * If all PEBs within the pool are used a new fastmap will be written
237  * to the flash and the pool gets refilled with empty PEBs.
238  *
239  */
240 struct ubi_fm_pool {
241 	int pebs[UBI_FM_MAX_POOL_SIZE];
242 	int used;
243 	int size;
244 	int max_size;
245 };
246 
247 /**
248  * struct ubi_volume - UBI volume description data structure.
249  * @dev: device object to make use of the the Linux device model
250  * @cdev: character device object to create character device
251  * @ubi: reference to the UBI device description object
252  * @vol_id: volume ID
253  * @ref_count: volume reference count
254  * @readers: number of users holding this volume in read-only mode
255  * @writers: number of users holding this volume in read-write mode
256  * @exclusive: whether somebody holds this volume in exclusive mode
257  *
258  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
259  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
260  * @usable_leb_size: logical eraseblock size without padding
261  * @used_ebs: how many logical eraseblocks in this volume contain data
262  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
263  * @used_bytes: how many bytes of data this volume contains
264  * @alignment: volume alignment
265  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
266  *            satisfy the requested alignment
267  * @name_len: volume name length
268  * @name: volume name
269  *
270  * @upd_ebs: how many eraseblocks are expected to be updated
271  * @ch_lnum: LEB number which is being changing by the atomic LEB change
272  *           operation
273  * @upd_bytes: how many bytes are expected to be received for volume update or
274  *             atomic LEB change
275  * @upd_received: how many bytes were already received for volume update or
276  *                atomic LEB change
277  * @upd_buf: update buffer which is used to collect update data or data for
278  *           atomic LEB change
279  *
280  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
281  * @checked: %1 if this static volume was checked
282  * @corrupted: %1 if the volume is corrupted (static volumes only)
283  * @upd_marker: %1 if the update marker is set for this volume
284  * @updating: %1 if the volume is being updated
285  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
286  * @direct_writes: %1 if direct writes are enabled for this volume
287  *
288  * The @corrupted field indicates that the volume's contents is corrupted.
289  * Since UBI protects only static volumes, this field is not relevant to
290  * dynamic volumes - it is user's responsibility to assure their data
291  * integrity.
292  *
293  * The @upd_marker flag indicates that this volume is either being updated at
294  * the moment or is damaged because of an unclean reboot.
295  */
296 struct ubi_volume {
297 	struct device dev;
298 	struct cdev cdev;
299 	struct ubi_device *ubi;
300 	int vol_id;
301 	int ref_count;
302 	int readers;
303 	int writers;
304 	int exclusive;
305 
306 	int reserved_pebs;
307 	int vol_type;
308 	int usable_leb_size;
309 	int used_ebs;
310 	int last_eb_bytes;
311 	long long used_bytes;
312 	int alignment;
313 	int data_pad;
314 	int name_len;
315 	char name[UBI_VOL_NAME_MAX + 1];
316 
317 	int upd_ebs;
318 	int ch_lnum;
319 	long long upd_bytes;
320 	long long upd_received;
321 	void *upd_buf;
322 
323 	int *eba_tbl;
324 	unsigned int checked:1;
325 	unsigned int corrupted:1;
326 	unsigned int upd_marker:1;
327 	unsigned int updating:1;
328 	unsigned int changing_leb:1;
329 	unsigned int direct_writes:1;
330 };
331 
332 /**
333  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
334  * @vol: reference to the corresponding volume description object
335  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
336  */
337 struct ubi_volume_desc {
338 	struct ubi_volume *vol;
339 	int mode;
340 };
341 
342 struct ubi_wl_entry;
343 
344 /**
345  * struct ubi_device - UBI device description structure
346  * @dev: UBI device object to use the the Linux device model
347  * @cdev: character device object to create character device
348  * @ubi_num: UBI device number
349  * @ubi_name: UBI device name
350  * @vol_count: number of volumes in this UBI device
351  * @volumes: volumes of this UBI device
352  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
353  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
354  *                @vol->readers, @vol->writers, @vol->exclusive,
355  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
356  * @ref_count: count of references on the UBI device
357  * @image_seq: image sequence number recorded on EC headers
358  *
359  * @rsvd_pebs: count of reserved physical eraseblocks
360  * @avail_pebs: count of available physical eraseblocks
361  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
362  *                 handling
363  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
364  *
365  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
366  *                     of UBI initialization
367  * @vtbl_slots: how many slots are available in the volume table
368  * @vtbl_size: size of the volume table in bytes
369  * @vtbl: in-RAM volume table copy
370  * @device_mutex: protects on-flash volume table and serializes volume
371  *                creation, deletion, update, re-size, re-name and set
372  *                property
373  *
374  * @max_ec: current highest erase counter value
375  * @mean_ec: current mean erase counter value
376  *
377  * @global_sqnum: global sequence number
378  * @ltree_lock: protects the lock tree and @global_sqnum
379  * @ltree: the lock tree
380  * @alc_mutex: serializes "atomic LEB change" operations
381  *
382  * @fm_disabled: non-zero if fastmap is disabled (default)
383  * @fm: in-memory data structure of the currently used fastmap
384  * @fm_pool: in-memory data structure of the fastmap pool
385  * @fm_wl_pool: in-memory data structure of the fastmap pool used by the WL
386  *		sub-system
387  * @fm_mutex: serializes ubi_update_fastmap() and protects @fm_buf
388  * @fm_buf: vmalloc()'d buffer which holds the raw fastmap
389  * @fm_size: fastmap size in bytes
390  * @fm_sem: allows ubi_update_fastmap() to block EBA table changes
391  * @fm_work: fastmap work queue
392  *
393  * @used: RB-tree of used physical eraseblocks
394  * @erroneous: RB-tree of erroneous used physical eraseblocks
395  * @free: RB-tree of free physical eraseblocks
396  * @free_count: Contains the number of elements in @free
397  * @scrub: RB-tree of physical eraseblocks which need scrubbing
398  * @pq: protection queue (contain physical eraseblocks which are temporarily
399  *      protected from the wear-leveling worker)
400  * @pq_head: protection queue head
401  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
402  *	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
403  *	     @erroneous, and @erroneous_peb_count fields
404  * @move_mutex: serializes eraseblock moves
405  * @work_sem: synchronizes the WL worker with use tasks
406  * @wl_scheduled: non-zero if the wear-leveling was scheduled
407  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
408  *             physical eraseblock
409  * @move_from: physical eraseblock from where the data is being moved
410  * @move_to: physical eraseblock where the data is being moved to
411  * @move_to_put: if the "to" PEB was put
412  * @works: list of pending works
413  * @works_count: count of pending works
414  * @bgt_thread: background thread description object
415  * @thread_enabled: if the background thread is enabled
416  * @bgt_name: background thread name
417  *
418  * @flash_size: underlying MTD device size (in bytes)
419  * @peb_count: count of physical eraseblocks on the MTD device
420  * @peb_size: physical eraseblock size
421  * @bad_peb_limit: top limit of expected bad physical eraseblocks
422  * @bad_peb_count: count of bad physical eraseblocks
423  * @good_peb_count: count of good physical eraseblocks
424  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
425  *                  used by UBI)
426  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
427  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
428  * @min_io_size: minimal input/output unit size of the underlying MTD device
429  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
430  * @ro_mode: if the UBI device is in read-only mode
431  * @leb_size: logical eraseblock size
432  * @leb_start: starting offset of logical eraseblocks within physical
433  *             eraseblocks
434  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
435  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
436  * @vid_hdr_offset: starting offset of the volume identifier header (might be
437  *                  unaligned)
438  * @vid_hdr_aloffset: starting offset of the VID header aligned to
439  * @hdrs_min_io_size
440  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
441  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
442  *               not
443  * @nor_flash: non-zero if working on top of NOR flash
444  * @max_write_size: maximum amount of bytes the underlying flash can write at a
445  *                  time (MTD write buffer size)
446  * @mtd: MTD device descriptor
447  *
448  * @peb_buf: a buffer of PEB size used for different purposes
449  * @buf_mutex: protects @peb_buf
450  * @ckvol_mutex: serializes static volume checking when opening
451  *
452  * @dbg: debugging information for this UBI device
453  */
454 struct ubi_device {
455 	struct cdev cdev;
456 	struct device dev;
457 	int ubi_num;
458 	char ubi_name[sizeof(UBI_NAME_STR)+5];
459 	int vol_count;
460 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
461 	spinlock_t volumes_lock;
462 	int ref_count;
463 	int image_seq;
464 
465 	int rsvd_pebs;
466 	int avail_pebs;
467 	int beb_rsvd_pebs;
468 	int beb_rsvd_level;
469 	int bad_peb_limit;
470 
471 	int autoresize_vol_id;
472 	int vtbl_slots;
473 	int vtbl_size;
474 	struct ubi_vtbl_record *vtbl;
475 	struct mutex device_mutex;
476 
477 	int max_ec;
478 	/* Note, mean_ec is not updated run-time - should be fixed */
479 	int mean_ec;
480 
481 	/* EBA sub-system's stuff */
482 	unsigned long long global_sqnum;
483 	spinlock_t ltree_lock;
484 	struct rb_root ltree;
485 	struct mutex alc_mutex;
486 
487 	/* Fastmap stuff */
488 	int fm_disabled;
489 	struct ubi_fastmap_layout *fm;
490 	struct ubi_fm_pool fm_pool;
491 	struct ubi_fm_pool fm_wl_pool;
492 	struct rw_semaphore fm_sem;
493 	struct mutex fm_mutex;
494 	void *fm_buf;
495 	size_t fm_size;
496 	struct work_struct fm_work;
497 
498 	/* Wear-leveling sub-system's stuff */
499 	struct rb_root used;
500 	struct rb_root erroneous;
501 	struct rb_root free;
502 	int free_count;
503 	struct rb_root scrub;
504 	struct list_head pq[UBI_PROT_QUEUE_LEN];
505 	int pq_head;
506 	spinlock_t wl_lock;
507 	struct mutex move_mutex;
508 	struct rw_semaphore work_sem;
509 	int wl_scheduled;
510 	struct ubi_wl_entry **lookuptbl;
511 	struct ubi_wl_entry *move_from;
512 	struct ubi_wl_entry *move_to;
513 	int move_to_put;
514 	struct list_head works;
515 	int works_count;
516 	struct task_struct *bgt_thread;
517 	int thread_enabled;
518 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
519 
520 	/* I/O sub-system's stuff */
521 	long long flash_size;
522 	int peb_count;
523 	int peb_size;
524 	int bad_peb_count;
525 	int good_peb_count;
526 	int corr_peb_count;
527 	int erroneous_peb_count;
528 	int max_erroneous;
529 	int min_io_size;
530 	int hdrs_min_io_size;
531 	int ro_mode;
532 	int leb_size;
533 	int leb_start;
534 	int ec_hdr_alsize;
535 	int vid_hdr_alsize;
536 	int vid_hdr_offset;
537 	int vid_hdr_aloffset;
538 	int vid_hdr_shift;
539 	unsigned int bad_allowed:1;
540 	unsigned int nor_flash:1;
541 	int max_write_size;
542 	struct mtd_info *mtd;
543 
544 	void *peb_buf;
545 	struct mutex buf_mutex;
546 	struct mutex ckvol_mutex;
547 
548 	struct ubi_debug_info *dbg;
549 };
550 
551 /**
552  * struct ubi_ainf_peb - attach information about a physical eraseblock.
553  * @ec: erase counter (%UBI_UNKNOWN if it is unknown)
554  * @pnum: physical eraseblock number
555  * @vol_id: ID of the volume this LEB belongs to
556  * @lnum: logical eraseblock number
557  * @scrub: if this physical eraseblock needs scrubbing
558  * @copy_flag: this LEB is a copy (@copy_flag is set in VID header of this LEB)
559  * @sqnum: sequence number
560  * @u: unions RB-tree or @list links
561  * @u.rb: link in the per-volume RB-tree of &struct ubi_ainf_peb objects
562  * @u.list: link in one of the eraseblock lists
563  *
564  * One object of this type is allocated for each physical eraseblock when
565  * attaching an MTD device. Note, if this PEB does not belong to any LEB /
566  * volume, the @vol_id and @lnum fields are initialized to %UBI_UNKNOWN.
567  */
568 struct ubi_ainf_peb {
569 	int ec;
570 	int pnum;
571 	int vol_id;
572 	int lnum;
573 	unsigned int scrub:1;
574 	unsigned int copy_flag:1;
575 	unsigned long long sqnum;
576 	union {
577 		struct rb_node rb;
578 		struct list_head list;
579 	} u;
580 };
581 
582 /**
583  * struct ubi_ainf_volume - attaching information about a volume.
584  * @vol_id: volume ID
585  * @highest_lnum: highest logical eraseblock number in this volume
586  * @leb_count: number of logical eraseblocks in this volume
587  * @vol_type: volume type
588  * @used_ebs: number of used logical eraseblocks in this volume (only for
589  *            static volumes)
590  * @last_data_size: amount of data in the last logical eraseblock of this
591  *                  volume (always equivalent to the usable logical eraseblock
592  *                  size in case of dynamic volumes)
593  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
594  *            are not used (due to volume alignment)
595  * @compat: compatibility flags of this volume
596  * @rb: link in the volume RB-tree
597  * @root: root of the RB-tree containing all the eraseblock belonging to this
598  *        volume (&struct ubi_ainf_peb objects)
599  *
600  * One object of this type is allocated for each volume when attaching an MTD
601  * device.
602  */
603 struct ubi_ainf_volume {
604 	int vol_id;
605 	int highest_lnum;
606 	int leb_count;
607 	int vol_type;
608 	int used_ebs;
609 	int last_data_size;
610 	int data_pad;
611 	int compat;
612 	struct rb_node rb;
613 	struct rb_root root;
614 };
615 
616 /**
617  * struct ubi_attach_info - MTD device attaching information.
618  * @volumes: root of the volume RB-tree
619  * @corr: list of corrupted physical eraseblocks
620  * @free: list of free physical eraseblocks
621  * @erase: list of physical eraseblocks which have to be erased
622  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
623  *         those belonging to "preserve"-compatible internal volumes)
624  * @corr_peb_count: count of PEBs in the @corr list
625  * @empty_peb_count: count of PEBs which are presumably empty (contain only
626  *                   0xFF bytes)
627  * @alien_peb_count: count of PEBs in the @alien list
628  * @bad_peb_count: count of bad physical eraseblocks
629  * @maybe_bad_peb_count: count of bad physical eraseblocks which are not marked
630  *                       as bad yet, but which look like bad
631  * @vols_found: number of volumes found
632  * @highest_vol_id: highest volume ID
633  * @is_empty: flag indicating whether the MTD device is empty or not
634  * @min_ec: lowest erase counter value
635  * @max_ec: highest erase counter value
636  * @max_sqnum: highest sequence number value
637  * @mean_ec: mean erase counter value
638  * @ec_sum: a temporary variable used when calculating @mean_ec
639  * @ec_count: a temporary variable used when calculating @mean_ec
640  * @aeb_slab_cache: slab cache for &struct ubi_ainf_peb objects
641  *
642  * This data structure contains the result of attaching an MTD device and may
643  * be used by other UBI sub-systems to build final UBI data structures, further
644  * error-recovery and so on.
645  */
646 struct ubi_attach_info {
647 	struct rb_root volumes;
648 	struct list_head corr;
649 	struct list_head free;
650 	struct list_head erase;
651 	struct list_head alien;
652 	int corr_peb_count;
653 	int empty_peb_count;
654 	int alien_peb_count;
655 	int bad_peb_count;
656 	int maybe_bad_peb_count;
657 	int vols_found;
658 	int highest_vol_id;
659 	int is_empty;
660 	int min_ec;
661 	int max_ec;
662 	unsigned long long max_sqnum;
663 	int mean_ec;
664 	uint64_t ec_sum;
665 	int ec_count;
666 	struct kmem_cache *aeb_slab_cache;
667 };
668 
669 /**
670  * struct ubi_work - UBI work description data structure.
671  * @list: a link in the list of pending works
672  * @func: worker function
673  * @e: physical eraseblock to erase
674  * @vol_id: the volume ID on which this erasure is being performed
675  * @lnum: the logical eraseblock number
676  * @torture: if the physical eraseblock has to be tortured
677  * @anchor: produce a anchor PEB to by used by fastmap
678  *
679  * The @func pointer points to the worker function. If the @cancel argument is
680  * not zero, the worker has to free the resources and exit immediately. The
681  * worker has to return zero in case of success and a negative error code in
682  * case of failure.
683  */
684 struct ubi_work {
685 	struct list_head list;
686 	int (*func)(struct ubi_device *ubi, struct ubi_work *wrk, int cancel);
687 	/* The below fields are only relevant to erasure works */
688 	struct ubi_wl_entry *e;
689 	int vol_id;
690 	int lnum;
691 	int torture;
692 	int anchor;
693 };
694 
695 #include "debug.h"
696 
697 extern struct kmem_cache *ubi_wl_entry_slab;
698 extern const struct file_operations ubi_ctrl_cdev_operations;
699 extern const struct file_operations ubi_cdev_operations;
700 extern const struct file_operations ubi_vol_cdev_operations;
701 extern struct class *ubi_class;
702 extern struct mutex ubi_devices_mutex;
703 extern struct blocking_notifier_head ubi_notifiers;
704 
705 /* attach.c */
706 int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
707 		  int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips);
708 struct ubi_ainf_volume *ubi_find_av(const struct ubi_attach_info *ai,
709 				    int vol_id);
710 void ubi_remove_av(struct ubi_attach_info *ai, struct ubi_ainf_volume *av);
711 struct ubi_ainf_peb *ubi_early_get_peb(struct ubi_device *ubi,
712 				       struct ubi_attach_info *ai);
713 int ubi_attach(struct ubi_device *ubi, int force_scan);
714 void ubi_destroy_ai(struct ubi_attach_info *ai);
715 
716 /* vtbl.c */
717 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
718 			   struct ubi_vtbl_record *vtbl_rec);
719 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
720 			    struct list_head *rename_list);
721 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_attach_info *ai);
722 
723 /* vmt.c */
724 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
725 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
726 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
727 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
728 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
729 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
730 
731 /* upd.c */
732 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
733 		     long long bytes);
734 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
735 			 const void __user *buf, int count);
736 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
737 			 const struct ubi_leb_change_req *req);
738 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
739 			     const void __user *buf, int count);
740 
741 /* misc.c */
742 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
743 		      int length);
744 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
745 void ubi_update_reserved(struct ubi_device *ubi);
746 void ubi_calculate_reserved(struct ubi_device *ubi);
747 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
748 
749 /* eba.c */
750 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
751 		      int lnum);
752 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
753 		     void *buf, int offset, int len, int check);
754 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
755 		      const void *buf, int offset, int len);
756 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
757 			 int lnum, const void *buf, int len, int used_ebs);
758 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
759 			      int lnum, const void *buf, int len);
760 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
761 		     struct ubi_vid_hdr *vid_hdr);
762 int ubi_eba_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
763 unsigned long long ubi_next_sqnum(struct ubi_device *ubi);
764 int self_check_eba(struct ubi_device *ubi, struct ubi_attach_info *ai_fastmap,
765 		   struct ubi_attach_info *ai_scan);
766 
767 /* wl.c */
768 int ubi_wl_get_peb(struct ubi_device *ubi);
769 int ubi_wl_put_peb(struct ubi_device *ubi, int vol_id, int lnum,
770 		   int pnum, int torture);
771 int ubi_wl_flush(struct ubi_device *ubi, int vol_id, int lnum);
772 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
773 int ubi_wl_init(struct ubi_device *ubi, struct ubi_attach_info *ai);
774 void ubi_wl_close(struct ubi_device *ubi);
775 int ubi_thread(void *u);
776 struct ubi_wl_entry *ubi_wl_get_fm_peb(struct ubi_device *ubi, int anchor);
777 int ubi_wl_put_fm_peb(struct ubi_device *ubi, struct ubi_wl_entry *used_e,
778 		      int lnum, int torture);
779 int ubi_is_erase_work(struct ubi_work *wrk);
780 void ubi_refill_pools(struct ubi_device *ubi);
781 int ubi_ensure_anchor_pebs(struct ubi_device *ubi);
782 
783 /* io.c */
784 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
785 		int len);
786 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
787 		 int len);
788 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
789 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
790 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
791 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
792 		       struct ubi_ec_hdr *ec_hdr, int verbose);
793 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
794 			struct ubi_ec_hdr *ec_hdr);
795 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
796 			struct ubi_vid_hdr *vid_hdr, int verbose);
797 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
798 			 struct ubi_vid_hdr *vid_hdr);
799 
800 /* build.c */
801 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
802 		       int vid_hdr_offset, int max_beb_per1024);
803 int ubi_detach_mtd_dev(int ubi_num, int anyway);
804 struct ubi_device *ubi_get_device(int ubi_num);
805 void ubi_put_device(struct ubi_device *ubi);
806 struct ubi_device *ubi_get_by_major(int major);
807 int ubi_major2num(int major);
808 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
809 		      int ntype);
810 int ubi_notify_all(struct ubi_device *ubi, int ntype,
811 		   struct notifier_block *nb);
812 int ubi_enumerate_volumes(struct notifier_block *nb);
813 void ubi_free_internal_volumes(struct ubi_device *ubi);
814 
815 /* kapi.c */
816 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
817 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
818 			    struct ubi_volume_info *vi);
819 /* scan.c */
820 int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
821 		      int pnum, const struct ubi_vid_hdr *vid_hdr);
822 
823 /* fastmap.c */
824 size_t ubi_calc_fm_size(struct ubi_device *ubi);
825 int ubi_update_fastmap(struct ubi_device *ubi);
826 int ubi_scan_fastmap(struct ubi_device *ubi, struct ubi_attach_info *ai,
827 		     int fm_anchor);
828 
829 /*
830  * ubi_rb_for_each_entry - walk an RB-tree.
831  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
832  * @pos: a pointer to RB-tree entry type to use as a loop counter
833  * @root: RB-tree's root
834  * @member: the name of the 'struct rb_node' within the RB-tree entry
835  */
836 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
837 	for (rb = rb_first(root),                                            \
838 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
839 	     rb;                                                             \
840 	     rb = rb_next(rb),                                               \
841 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
842 
843 /*
844  * ubi_move_aeb_to_list - move a PEB from the volume tree to a list.
845  *
846  * @av: volume attaching information
847  * @aeb: attaching eraseblock information
848  * @list: the list to move to
849  */
850 static inline void ubi_move_aeb_to_list(struct ubi_ainf_volume *av,
851 					 struct ubi_ainf_peb *aeb,
852 					 struct list_head *list)
853 {
854 		rb_erase(&aeb->u.rb, &av->root);
855 		list_add_tail(&aeb->u.list, list);
856 }
857 
858 /**
859  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
860  * @ubi: UBI device description object
861  * @gfp_flags: GFP flags to allocate with
862  *
863  * This function returns a pointer to the newly allocated and zero-filled
864  * volume identifier header object in case of success and %NULL in case of
865  * failure.
866  */
867 static inline struct ubi_vid_hdr *
868 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
869 {
870 	void *vid_hdr;
871 
872 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
873 	if (!vid_hdr)
874 		return NULL;
875 
876 	/*
877 	 * VID headers may be stored at un-aligned flash offsets, so we shift
878 	 * the pointer.
879 	 */
880 	return vid_hdr + ubi->vid_hdr_shift;
881 }
882 
883 /**
884  * ubi_free_vid_hdr - free a volume identifier header object.
885  * @ubi: UBI device description object
886  * @vid_hdr: the object to free
887  */
888 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
889 				    struct ubi_vid_hdr *vid_hdr)
890 {
891 	void *p = vid_hdr;
892 
893 	if (!p)
894 		return;
895 
896 	kfree(p - ubi->vid_hdr_shift);
897 }
898 
899 /*
900  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
901  * the beginning of the logical eraseblock, not to the beginning of the
902  * physical eraseblock.
903  */
904 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
905 				   int pnum, int offset, int len)
906 {
907 	ubi_assert(offset >= 0);
908 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
909 }
910 
911 /*
912  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
913  * the beginning of the logical eraseblock, not to the beginning of the
914  * physical eraseblock.
915  */
916 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
917 				    int pnum, int offset, int len)
918 {
919 	ubi_assert(offset >= 0);
920 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
921 }
922 
923 /**
924  * ubi_ro_mode - switch to read-only mode.
925  * @ubi: UBI device description object
926  */
927 static inline void ubi_ro_mode(struct ubi_device *ubi)
928 {
929 	if (!ubi->ro_mode) {
930 		ubi->ro_mode = 1;
931 		ubi_warn("switch to read-only mode");
932 		dump_stack();
933 	}
934 }
935 
936 /**
937  * vol_id2idx - get table index by volume ID.
938  * @ubi: UBI device description object
939  * @vol_id: volume ID
940  */
941 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
942 {
943 	if (vol_id >= UBI_INTERNAL_VOL_START)
944 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
945 	else
946 		return vol_id;
947 }
948 
949 /**
950  * idx2vol_id - get volume ID by table index.
951  * @ubi: UBI device description object
952  * @idx: table index
953  */
954 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
955 {
956 	if (idx >= ubi->vtbl_slots)
957 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
958 	else
959 		return idx;
960 }
961 
962 #endif /* !__UBI_UBI_H__ */
963