xref: /openbmc/linux/drivers/mtd/ubi/ubi.h (revision 643d1f7f)
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/string.h>
38 #include <linux/vmalloc.h>
39 #include <linux/mtd/mtd.h>
40 
41 #include <mtd/ubi-header.h>
42 #include <linux/mtd/ubi.h>
43 
44 #include "scan.h"
45 #include "debug.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, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
55 /* UBI warning messages */
56 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
57 				  __FUNCTION__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
60 				 __FUNCTION__, ##__VA_ARGS__)
61 
62 /* Lowest number PEBs reserved for bad PEB handling */
63 #define MIN_RESEVED_PEBS 2
64 
65 /* Background thread name pattern */
66 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
67 
68 /* This marker in the EBA table means that the LEB is um-mapped */
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  * Error codes returned by the I/O unit.
79  *
80  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
81  * 0xFF bytes
82  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
83  * valid erase counter header, and the rest are %0xFF bytes
84  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
85  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
86  * CRC)
87  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
88  */
89 enum {
90 	UBI_IO_PEB_EMPTY = 1,
91 	UBI_IO_PEB_FREE,
92 	UBI_IO_BAD_EC_HDR,
93 	UBI_IO_BAD_VID_HDR,
94 	UBI_IO_BITFLIPS
95 };
96 
97 extern int ubi_devices_cnt;
98 extern struct ubi_device *ubi_devices[];
99 
100 struct ubi_volume_desc;
101 
102 /**
103  * struct ubi_volume - UBI volume description data structure.
104  * @dev: device object to make use of the the Linux device model
105  * @cdev: character device object to create character device
106  * @ubi: reference to the UBI device description object
107  * @vol_id: volume ID
108  * @readers: number of users holding this volume in read-only mode
109  * @writers: number of users holding this volume in read-write mode
110  * @exclusive: whether somebody holds this volume in exclusive mode
111  * @removed: if the volume was removed
112  * @checked: if this static volume was checked
113  *
114  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
115  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
116  * @usable_leb_size: logical eraseblock size without padding
117  * @used_ebs: how many logical eraseblocks in this volume contain data
118  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
119  * @used_bytes: how many bytes of data this volume contains
120  * @upd_marker: non-zero if the update marker is set for this volume
121  * @corrupted: non-zero if the volume is corrupted (static volumes only)
122  * @alignment: volume alignment
123  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
124  * satisfy the requested alignment
125  * @name_len: volume name length
126  * @name: volume name
127  *
128  * @updating: whether the volume is being updated
129  * @upd_ebs: how many eraseblocks are expected to be updated
130  * @upd_bytes: how many bytes are expected to be received
131  * @upd_received: how many update bytes were already received
132  * @upd_buf: update buffer which is used to collect update data
133  *
134  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
135  *
136  * @gluebi_desc: gluebi UBI volume descriptor
137  * @gluebi_refcount: reference count of the gluebi MTD device
138  * @gluebi_mtd: MTD device description object of the gluebi MTD device
139  *
140  * The @corrupted field indicates that the volume's contents is corrupted.
141  * Since UBI protects only static volumes, this field is not relevant to
142  * dynamic volumes - it is user's responsibility to assure their data
143  * integrity.
144  *
145  * The @upd_marker flag indicates that this volume is either being updated at
146  * the moment or is damaged because of an unclean reboot.
147  */
148 struct ubi_volume {
149 	struct device dev;
150 	struct cdev cdev;
151 	struct ubi_device *ubi;
152 	int vol_id;
153 	int readers;
154 	int writers;
155 	int exclusive;
156 	int removed;
157 	int checked;
158 
159 	int reserved_pebs;
160 	int vol_type;
161 	int usable_leb_size;
162 	int used_ebs;
163 	int last_eb_bytes;
164 	long long used_bytes;
165 	int upd_marker;
166 	int corrupted;
167 	int alignment;
168 	int data_pad;
169 	int name_len;
170 	char name[UBI_VOL_NAME_MAX+1];
171 
172 	int updating;
173 	int upd_ebs;
174 	long long upd_bytes;
175 	long long upd_received;
176 	void *upd_buf;
177 
178 	int *eba_tbl;
179 
180 #ifdef CONFIG_MTD_UBI_GLUEBI
181 	/* Gluebi-related stuff may be compiled out */
182 	struct ubi_volume_desc *gluebi_desc;
183 	int gluebi_refcount;
184 	struct mtd_info gluebi_mtd;
185 #endif
186 };
187 
188 /**
189  * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
190  * opened.
191  * @vol: reference to the corresponding volume description object
192  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
193  */
194 struct ubi_volume_desc {
195 	struct ubi_volume *vol;
196 	int mode;
197 };
198 
199 struct ubi_wl_entry;
200 
201 /**
202  * struct ubi_device - UBI device description structure
203  * @dev: class device object to use the the Linux device model
204  * @cdev: character device object to create character device
205  * @ubi_num: UBI device number
206  * @ubi_name: UBI device name
207  * @major: character device major number
208  * @vol_count: number of volumes in this UBI device
209  * @volumes: volumes of this UBI device
210  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
211  * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, @vol->readers,
212  * @vol->writers, @vol->exclusive, @vol->removed, @vol->mapping and
213  * @vol->eba_tbl.
214  *
215  * @rsvd_pebs: count of reserved physical eraseblocks
216  * @avail_pebs: count of available physical eraseblocks
217  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
218  * handling
219  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
220  *
221  * @vtbl_slots: how many slots are available in the volume table
222  * @vtbl_size: size of the volume table in bytes
223  * @vtbl: in-RAM volume table copy
224  * @vtbl_mutex: protects on-flash volume table
225  *
226  * @max_ec: current highest erase counter value
227  * @mean_ec: current mean erase counter value
228  *
229  * @global_sqnum: global sequence number
230  * @ltree_lock: protects the lock tree and @global_sqnum
231  * @ltree: the lock tree
232  * @alc_mutex: serializes "atomic LEB change" operations
233  *
234  * @used: RB-tree of used physical eraseblocks
235  * @free: RB-tree of free physical eraseblocks
236  * @scrub: RB-tree of physical eraseblocks which need scrubbing
237  * @prot: protection trees
238  * @prot.pnum: protection tree indexed by physical eraseblock numbers
239  * @prot.aec: protection tree indexed by absolute erase counter value
240  * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
241  * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
242  * fields
243  * @wl_scheduled: non-zero if the wear-leveling was scheduled
244  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
245  * physical eraseblock
246  * @abs_ec: absolute erase counter
247  * @move_from: physical eraseblock from where the data is being moved
248  * @move_to: physical eraseblock where the data is being moved to
249  * @move_from_put: if the "from" PEB was put
250  * @move_to_put: if the "to" PEB was put
251  * @works: list of pending works
252  * @works_count: count of pending works
253  * @bgt_thread: background thread description object
254  * @thread_enabled: if the background thread is enabled
255  * @bgt_name: background thread name
256  *
257  * @flash_size: underlying MTD device size (in bytes)
258  * @peb_count: count of physical eraseblocks on the MTD device
259  * @peb_size: physical eraseblock size
260  * @bad_peb_count: count of bad physical eraseblocks
261  * @good_peb_count: count of good physical eraseblocks
262  * @min_io_size: minimal input/output unit size of the underlying MTD device
263  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
264  * @ro_mode: if the UBI device is in read-only mode
265  * @leb_size: logical eraseblock size
266  * @leb_start: starting offset of logical eraseblocks within physical
267  * eraseblocks
268  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
269  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
270  * @vid_hdr_offset: starting offset of the volume identifier header (might be
271  * unaligned)
272  * @vid_hdr_aloffset: starting offset of the VID header aligned to
273  * @hdrs_min_io_size
274  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
275  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
276  * not
277  * @mtd: MTD device descriptor
278  *
279  * @peb_buf1: a buffer of PEB size used for different purposes
280  * @peb_buf2: another buffer of PEB size used for different purposes
281  * @buf_mutex: proptects @peb_buf1 and @peb_buf2
282  * @dbg_peb_buf:  buffer of PEB size used for debugging
283  * @dbg_buf_mutex: proptects @dbg_peb_buf
284  */
285 struct ubi_device {
286 	struct cdev cdev;
287 	struct device dev;
288 	int ubi_num;
289 	char ubi_name[sizeof(UBI_NAME_STR)+5];
290 	int major;
291 	int vol_count;
292 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
293 	spinlock_t volumes_lock;
294 
295 	int rsvd_pebs;
296 	int avail_pebs;
297 	int beb_rsvd_pebs;
298 	int beb_rsvd_level;
299 
300 	int vtbl_slots;
301 	int vtbl_size;
302 	struct ubi_vtbl_record *vtbl;
303 	struct mutex vtbl_mutex;
304 
305 	int max_ec;
306 	int mean_ec;
307 
308 	/* EBA unit's stuff */
309 	unsigned long long global_sqnum;
310 	spinlock_t ltree_lock;
311 	struct rb_root ltree;
312 	struct mutex alc_mutex;
313 
314 	/* Wear-leveling unit's stuff */
315 	struct rb_root used;
316 	struct rb_root free;
317 	struct rb_root scrub;
318 	struct {
319 		struct rb_root pnum;
320 		struct rb_root aec;
321 	} prot;
322 	spinlock_t wl_lock;
323 	int wl_scheduled;
324 	struct ubi_wl_entry **lookuptbl;
325 	unsigned long long abs_ec;
326 	struct ubi_wl_entry *move_from;
327 	struct ubi_wl_entry *move_to;
328 	int move_from_put;
329 	int move_to_put;
330 	struct list_head works;
331 	int works_count;
332 	struct task_struct *bgt_thread;
333 	int thread_enabled;
334 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
335 
336 	/* I/O unit's stuff */
337 	long long flash_size;
338 	int peb_count;
339 	int peb_size;
340 	int bad_peb_count;
341 	int good_peb_count;
342 	int min_io_size;
343 	int hdrs_min_io_size;
344 	int ro_mode;
345 	int leb_size;
346 	int leb_start;
347 	int ec_hdr_alsize;
348 	int vid_hdr_alsize;
349 	int vid_hdr_offset;
350 	int vid_hdr_aloffset;
351 	int vid_hdr_shift;
352 	int bad_allowed;
353 	struct mtd_info *mtd;
354 
355 	void *peb_buf1;
356 	void *peb_buf2;
357 	struct mutex buf_mutex;
358 #ifdef CONFIG_MTD_UBI_DEBUG
359 	void *dbg_peb_buf;
360 	struct mutex dbg_buf_mutex;
361 #endif
362 };
363 
364 extern struct file_operations ubi_cdev_operations;
365 extern struct file_operations ubi_vol_cdev_operations;
366 extern struct class *ubi_class;
367 
368 /* vtbl.c */
369 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
370 			   struct ubi_vtbl_record *vtbl_rec);
371 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
372 
373 /* vmt.c */
374 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
375 int ubi_remove_volume(struct ubi_volume_desc *desc);
376 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
377 int ubi_add_volume(struct ubi_device *ubi, int vol_id);
378 void ubi_free_volume(struct ubi_device *ubi, int vol_id);
379 
380 /* upd.c */
381 int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
382 int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
383 			 const void __user *buf, int count);
384 
385 /* misc.c */
386 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
387 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
388 void ubi_calculate_reserved(struct ubi_device *ubi);
389 
390 /* gluebi.c */
391 #ifdef CONFIG_MTD_UBI_GLUEBI
392 int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
393 int ubi_destroy_gluebi(struct ubi_volume *vol);
394 void ubi_gluebi_updated(struct ubi_volume *vol);
395 #else
396 #define ubi_create_gluebi(ubi, vol) 0
397 #define ubi_destroy_gluebi(vol) 0
398 #define ubi_gluebi_updated(vol)
399 #endif
400 
401 /* eba.c */
402 int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum);
403 int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
404 		     int offset, int len, int check);
405 int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
406 		      const void *buf, int offset, int len, int dtype);
407 int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
408 			 const void *buf, int len, int dtype,
409 			 int used_ebs);
410 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
411 			      const void *buf, int len, int dtype);
412 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
413 		     struct ubi_vid_hdr *vid_hdr);
414 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
415 void ubi_eba_close(const struct ubi_device *ubi);
416 
417 /* wl.c */
418 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
419 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
420 int ubi_wl_flush(struct ubi_device *ubi);
421 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
422 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
423 void ubi_wl_close(struct ubi_device *ubi);
424 
425 /* io.c */
426 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
427 		int len);
428 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
429 		 int len);
430 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
431 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
432 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
433 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
434 		       struct ubi_ec_hdr *ec_hdr, int verbose);
435 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
436 			struct ubi_ec_hdr *ec_hdr);
437 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
438 			struct ubi_vid_hdr *vid_hdr, int verbose);
439 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
440 			 struct ubi_vid_hdr *vid_hdr);
441 
442 /*
443  * ubi_rb_for_each_entry - walk an RB-tree.
444  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
445  * @pos: a pointer to RB-tree entry type to use as a loop counter
446  * @root: RB-tree's root
447  * @member: the name of the 'struct rb_node' within the RB-tree entry
448  */
449 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
450 	for (rb = rb_first(root),                                            \
451 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
452 	     rb;                                                             \
453 	     rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
454 
455 /**
456  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
457  * @ubi: UBI device description object
458  * @gfp_flags: GFP flags to allocate with
459  *
460  * This function returns a pointer to the newly allocated and zero-filled
461  * volume identifier header object in case of success and %NULL in case of
462  * failure.
463  */
464 static inline struct ubi_vid_hdr *
465 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
466 {
467 	void *vid_hdr;
468 
469 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
470 	if (!vid_hdr)
471 		return NULL;
472 
473 	/*
474 	 * VID headers may be stored at un-aligned flash offsets, so we shift
475 	 * the pointer.
476 	 */
477 	return vid_hdr + ubi->vid_hdr_shift;
478 }
479 
480 /**
481  * ubi_free_vid_hdr - free a volume identifier header object.
482  * @ubi: UBI device description object
483  * @vid_hdr: the object to free
484  */
485 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
486 				    struct ubi_vid_hdr *vid_hdr)
487 {
488 	void *p = vid_hdr;
489 
490 	if (!p)
491 		return;
492 
493 	kfree(p - ubi->vid_hdr_shift);
494 }
495 
496 /*
497  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
498  * the beginning of the logical eraseblock, not to the beginning of the
499  * physical eraseblock.
500  */
501 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
502 				   int pnum, int offset, int len)
503 {
504 	ubi_assert(offset >= 0);
505 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
506 }
507 
508 /*
509  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
510  * the beginning of the logical eraseblock, not to the beginning of the
511  * physical eraseblock.
512  */
513 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
514 				    int pnum, int offset, int len)
515 {
516 	ubi_assert(offset >= 0);
517 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
518 }
519 
520 /**
521  * ubi_ro_mode - switch to read-only mode.
522  * @ubi: UBI device description object
523  */
524 static inline void ubi_ro_mode(struct ubi_device *ubi)
525 {
526 	ubi->ro_mode = 1;
527 	ubi_warn("switch to read-only mode");
528 }
529 
530 /**
531  * vol_id2idx - get table index by volume ID.
532  * @ubi: UBI device description object
533  * @vol_id: volume ID
534  */
535 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
536 {
537 	if (vol_id >= UBI_INTERNAL_VOL_START)
538 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
539 	else
540 		return vol_id;
541 }
542 
543 /**
544  * idx2vol_id - get volume ID by table index.
545  * @ubi: UBI device description object
546  * @idx: table index
547  */
548 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
549 {
550 	if (idx >= ubi->vtbl_slots)
551 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
552 	else
553 		return idx;
554 }
555 
556 #endif /* !__UBI_UBI_H__ */
557