xref: /linux/drivers/mtd/ubi/ubi.h (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
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 
44 #include "ubi-media.h"
45 #include "scan.h"
46 #include "debug.h"
47 
48 /* Maximum number of supported UBI devices */
49 #define UBI_MAX_DEVICES 32
50 
51 /* UBI name used for character devices, sysfs, etc */
52 #define UBI_NAME_STR "ubi"
53 
54 /* Normal UBI messages */
55 #define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
56 /* UBI warning messages */
57 #define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
58 				  __func__, ##__VA_ARGS__)
59 /* UBI error messages */
60 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
61 				 __func__, ##__VA_ARGS__)
62 
63 /* Lowest number PEBs reserved for bad PEB handling */
64 #define MIN_RESEVED_PEBS 2
65 
66 /* Background thread name pattern */
67 #define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
68 
69 /* This marker in the EBA table means that the LEB is um-mapped */
70 #define UBI_LEB_UNMAPPED -1
71 
72 /*
73  * In case of errors, UBI tries to repeat the operation several times before
74  * returning error. The below constant defines how many times UBI re-tries.
75  */
76 #define UBI_IO_RETRIES 3
77 
78 /*
79  * Length of the protection queue. The length is effectively equivalent to the
80  * number of (global) erase cycles PEBs are protected from the wear-leveling
81  * worker.
82  */
83 #define UBI_PROT_QUEUE_LEN 10
84 
85 /*
86  * Error codes returned by the I/O sub-system.
87  *
88  * UBI_IO_FF: the read region of flash contains only 0xFFs
89  * UBI_IO_FF_BITFLIPS: the same as %UBI_IO_FF, but also also there was a data
90  *                     integrity error reported by the MTD driver
91  *                     (uncorrectable ECC error in case of NAND)
92  * UBI_IO_BAD_HDR: the EC or VID header is corrupted (bad magic or CRC)
93  * UBI_IO_BAD_HDR_EBADMSG: the same as %UBI_IO_BAD_HDR, but also there was a
94  *                         data integrity error reported by the MTD driver
95  *                         (uncorrectable ECC error in case of NAND)
96  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
97  *
98  * Note, it is probably better to have bit-flip and ebadmsg as flags which can
99  * be or'ed with other error code. But this is a big change because there are
100  * may callers, so it does not worth the risk of introducing a bug
101  */
102 enum {
103 	UBI_IO_FF = 1,
104 	UBI_IO_FF_BITFLIPS,
105 	UBI_IO_BAD_HDR,
106 	UBI_IO_BAD_HDR_EBADMSG,
107 	UBI_IO_BITFLIPS,
108 };
109 
110 /*
111  * Return codes of the 'ubi_eba_copy_leb()' function.
112  *
113  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
114  *                   PEB was put meanwhile, or there is I/O on the source PEB
115  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
116  *                     PEB
117  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
118  *                     PEB
119  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
120  *                     PEB
121  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
122  *                       target PEB
123  */
124 enum {
125 	MOVE_CANCEL_RACE = 1,
126 	MOVE_SOURCE_RD_ERR,
127 	MOVE_TARGET_RD_ERR,
128 	MOVE_TARGET_WR_ERR,
129 	MOVE_CANCEL_BITFLIPS,
130 };
131 
132 /**
133  * struct ubi_wl_entry - wear-leveling entry.
134  * @u.rb: link in the corresponding (free/used) RB-tree
135  * @u.list: link in the protection queue
136  * @ec: erase counter
137  * @pnum: physical eraseblock number
138  *
139  * This data structure is used in the WL sub-system. Each physical eraseblock
140  * has a corresponding &struct wl_entry object which may be kept in different
141  * RB-trees. See WL sub-system for details.
142  */
143 struct ubi_wl_entry {
144 	union {
145 		struct rb_node rb;
146 		struct list_head list;
147 	} u;
148 	int ec;
149 	int pnum;
150 };
151 
152 /**
153  * struct ubi_ltree_entry - an entry in the lock tree.
154  * @rb: links RB-tree nodes
155  * @vol_id: volume ID of the locked logical eraseblock
156  * @lnum: locked logical eraseblock number
157  * @users: how many tasks are using this logical eraseblock or wait for it
158  * @mutex: read/write mutex to implement read/write access serialization to
159  *         the (@vol_id, @lnum) logical eraseblock
160  *
161  * This data structure is used in the EBA sub-system to implement per-LEB
162  * locking. When a logical eraseblock is being locked - corresponding
163  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
164  * See EBA sub-system for details.
165  */
166 struct ubi_ltree_entry {
167 	struct rb_node rb;
168 	int vol_id;
169 	int lnum;
170 	int users;
171 	struct rw_semaphore mutex;
172 };
173 
174 /**
175  * struct ubi_rename_entry - volume re-name description data structure.
176  * @new_name_len: new volume name length
177  * @new_name: new volume name
178  * @remove: if not zero, this volume should be removed, not re-named
179  * @desc: descriptor of the volume
180  * @list: links re-name entries into a list
181  *
182  * This data structure is utilized in the multiple volume re-name code. Namely,
183  * UBI first creates a list of &struct ubi_rename_entry objects from the
184  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
185  * the job.
186  */
187 struct ubi_rename_entry {
188 	int new_name_len;
189 	char new_name[UBI_VOL_NAME_MAX + 1];
190 	int remove;
191 	struct ubi_volume_desc *desc;
192 	struct list_head list;
193 };
194 
195 struct ubi_volume_desc;
196 
197 /**
198  * struct ubi_volume - UBI volume description data structure.
199  * @dev: device object to make use of the the Linux device model
200  * @cdev: character device object to create character device
201  * @ubi: reference to the UBI device description object
202  * @vol_id: volume ID
203  * @ref_count: volume reference count
204  * @readers: number of users holding this volume in read-only mode
205  * @writers: number of users holding this volume in read-write mode
206  * @exclusive: whether somebody holds this volume in exclusive mode
207  *
208  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
209  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
210  * @usable_leb_size: logical eraseblock size without padding
211  * @used_ebs: how many logical eraseblocks in this volume contain data
212  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
213  * @used_bytes: how many bytes of data this volume contains
214  * @alignment: volume alignment
215  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
216  *            satisfy the requested alignment
217  * @name_len: volume name length
218  * @name: volume name
219  *
220  * @upd_ebs: how many eraseblocks are expected to be updated
221  * @ch_lnum: LEB number which is being changing by the atomic LEB change
222  *           operation
223  * @ch_dtype: data persistency type which is being changing by the atomic LEB
224  *            change operation
225  * @upd_bytes: how many bytes are expected to be received for volume update or
226  *             atomic LEB change
227  * @upd_received: how many bytes were already received for volume update or
228  *                atomic LEB change
229  * @upd_buf: update buffer which is used to collect update data or data for
230  *           atomic LEB change
231  *
232  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
233  * @checked: %1 if this static volume was checked
234  * @corrupted: %1 if the volume is corrupted (static volumes only)
235  * @upd_marker: %1 if the update marker is set for this volume
236  * @updating: %1 if the volume is being updated
237  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
238  * @direct_writes: %1 if direct writes are enabled for this volume
239  *
240  * The @corrupted field indicates that the volume's contents is corrupted.
241  * Since UBI protects only static volumes, this field is not relevant to
242  * dynamic volumes - it is user's responsibility to assure their data
243  * integrity.
244  *
245  * The @upd_marker flag indicates that this volume is either being updated at
246  * the moment or is damaged because of an unclean reboot.
247  */
248 struct ubi_volume {
249 	struct device dev;
250 	struct cdev cdev;
251 	struct ubi_device *ubi;
252 	int vol_id;
253 	int ref_count;
254 	int readers;
255 	int writers;
256 	int exclusive;
257 
258 	int reserved_pebs;
259 	int vol_type;
260 	int usable_leb_size;
261 	int used_ebs;
262 	int last_eb_bytes;
263 	long long used_bytes;
264 	int alignment;
265 	int data_pad;
266 	int name_len;
267 	char name[UBI_VOL_NAME_MAX + 1];
268 
269 	int upd_ebs;
270 	int ch_lnum;
271 	int ch_dtype;
272 	long long upd_bytes;
273 	long long upd_received;
274 	void *upd_buf;
275 
276 	int *eba_tbl;
277 	unsigned int checked:1;
278 	unsigned int corrupted:1;
279 	unsigned int upd_marker:1;
280 	unsigned int updating:1;
281 	unsigned int changing_leb:1;
282 	unsigned int direct_writes:1;
283 };
284 
285 /**
286  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
287  * @vol: reference to the corresponding volume description object
288  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
289  */
290 struct ubi_volume_desc {
291 	struct ubi_volume *vol;
292 	int mode;
293 };
294 
295 struct ubi_wl_entry;
296 
297 /**
298  * struct ubi_device - UBI device description structure
299  * @dev: UBI device object to use the the Linux device model
300  * @cdev: character device object to create character device
301  * @ubi_num: UBI device number
302  * @ubi_name: UBI device name
303  * @vol_count: number of volumes in this UBI device
304  * @volumes: volumes of this UBI device
305  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
306  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
307  *                @vol->readers, @vol->writers, @vol->exclusive,
308  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
309  * @ref_count: count of references on the UBI device
310  * @image_seq: image sequence number recorded on EC headers
311  *
312  * @rsvd_pebs: count of reserved physical eraseblocks
313  * @avail_pebs: count of available physical eraseblocks
314  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
315  *                 handling
316  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
317  *
318  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
319  *                     of UBI initialization
320  * @vtbl_slots: how many slots are available in the volume table
321  * @vtbl_size: size of the volume table in bytes
322  * @vtbl: in-RAM volume table copy
323  * @device_mutex: protects on-flash volume table and serializes volume
324  *                creation, deletion, update, re-size, re-name and set
325  *                property
326  *
327  * @max_ec: current highest erase counter value
328  * @mean_ec: current mean erase counter value
329  *
330  * @global_sqnum: global sequence number
331  * @ltree_lock: protects the lock tree and @global_sqnum
332  * @ltree: the lock tree
333  * @alc_mutex: serializes "atomic LEB change" operations
334  *
335  * @used: RB-tree of used physical eraseblocks
336  * @erroneous: RB-tree of erroneous used physical eraseblocks
337  * @free: RB-tree of free physical eraseblocks
338  * @scrub: RB-tree of physical eraseblocks which need scrubbing
339  * @pq: protection queue (contain physical eraseblocks which are temporarily
340  *      protected from the wear-leveling worker)
341  * @pq_head: protection queue head
342  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
343  * 	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
344  * 	     @erroneous, and @erroneous_peb_count fields
345  * @move_mutex: serializes eraseblock moves
346  * @work_sem: synchronizes the WL worker with use tasks
347  * @wl_scheduled: non-zero if the wear-leveling was scheduled
348  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
349  *             physical eraseblock
350  * @move_from: physical eraseblock from where the data is being moved
351  * @move_to: physical eraseblock where the data is being moved to
352  * @move_to_put: if the "to" PEB was put
353  * @works: list of pending works
354  * @works_count: count of pending works
355  * @bgt_thread: background thread description object
356  * @thread_enabled: if the background thread is enabled
357  * @bgt_name: background thread name
358  *
359  * @flash_size: underlying MTD device size (in bytes)
360  * @peb_count: count of physical eraseblocks on the MTD device
361  * @peb_size: physical eraseblock size
362  * @bad_peb_count: count of bad physical eraseblocks
363  * @good_peb_count: count of good physical eraseblocks
364  * @corr_peb_count: count of corrupted physical eraseblocks (preserved and not
365  *                  used by UBI)
366  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
367  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
368  * @min_io_size: minimal input/output unit size of the underlying MTD device
369  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
370  * @ro_mode: if the UBI device is in read-only mode
371  * @leb_size: logical eraseblock size
372  * @leb_start: starting offset of logical eraseblocks within physical
373  *             eraseblocks
374  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
375  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
376  * @vid_hdr_offset: starting offset of the volume identifier header (might be
377  *                  unaligned)
378  * @vid_hdr_aloffset: starting offset of the VID header aligned to
379  * @hdrs_min_io_size
380  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
381  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
382  *               not
383  * @nor_flash: non-zero if working on top of NOR flash
384  * @mtd: MTD device descriptor
385  *
386  * @peb_buf1: a buffer of PEB size used for different purposes
387  * @peb_buf2: another buffer of PEB size used for different purposes
388  * @buf_mutex: protects @peb_buf1 and @peb_buf2
389  * @ckvol_mutex: serializes static volume checking when opening
390  * @dbg_peb_buf: buffer of PEB size used for debugging
391  * @dbg_buf_mutex: protects @dbg_peb_buf
392  */
393 struct ubi_device {
394 	struct cdev cdev;
395 	struct device dev;
396 	int ubi_num;
397 	char ubi_name[sizeof(UBI_NAME_STR)+5];
398 	int vol_count;
399 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
400 	spinlock_t volumes_lock;
401 	int ref_count;
402 	int image_seq;
403 
404 	int rsvd_pebs;
405 	int avail_pebs;
406 	int beb_rsvd_pebs;
407 	int beb_rsvd_level;
408 
409 	int autoresize_vol_id;
410 	int vtbl_slots;
411 	int vtbl_size;
412 	struct ubi_vtbl_record *vtbl;
413 	struct mutex device_mutex;
414 
415 	int max_ec;
416 	/* Note, mean_ec is not updated run-time - should be fixed */
417 	int mean_ec;
418 
419 	/* EBA sub-system's stuff */
420 	unsigned long long global_sqnum;
421 	spinlock_t ltree_lock;
422 	struct rb_root ltree;
423 	struct mutex alc_mutex;
424 
425 	/* Wear-leveling sub-system's stuff */
426 	struct rb_root used;
427 	struct rb_root erroneous;
428 	struct rb_root free;
429 	struct rb_root scrub;
430 	struct list_head pq[UBI_PROT_QUEUE_LEN];
431 	int pq_head;
432 	spinlock_t wl_lock;
433 	struct mutex move_mutex;
434 	struct rw_semaphore work_sem;
435 	int wl_scheduled;
436 	struct ubi_wl_entry **lookuptbl;
437 	struct ubi_wl_entry *move_from;
438 	struct ubi_wl_entry *move_to;
439 	int move_to_put;
440 	struct list_head works;
441 	int works_count;
442 	struct task_struct *bgt_thread;
443 	int thread_enabled;
444 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
445 
446 	/* I/O sub-system's stuff */
447 	long long flash_size;
448 	int peb_count;
449 	int peb_size;
450 	int bad_peb_count;
451 	int good_peb_count;
452 	int corr_peb_count;
453 	int erroneous_peb_count;
454 	int max_erroneous;
455 	int min_io_size;
456 	int hdrs_min_io_size;
457 	int ro_mode;
458 	int leb_size;
459 	int leb_start;
460 	int ec_hdr_alsize;
461 	int vid_hdr_alsize;
462 	int vid_hdr_offset;
463 	int vid_hdr_aloffset;
464 	int vid_hdr_shift;
465 	unsigned int bad_allowed:1;
466 	unsigned int nor_flash:1;
467 	struct mtd_info *mtd;
468 
469 	void *peb_buf1;
470 	void *peb_buf2;
471 	struct mutex buf_mutex;
472 	struct mutex ckvol_mutex;
473 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
474 	void *dbg_peb_buf;
475 	struct mutex dbg_buf_mutex;
476 #endif
477 };
478 
479 extern struct kmem_cache *ubi_wl_entry_slab;
480 extern const struct file_operations ubi_ctrl_cdev_operations;
481 extern const struct file_operations ubi_cdev_operations;
482 extern const struct file_operations ubi_vol_cdev_operations;
483 extern struct class *ubi_class;
484 extern struct mutex ubi_devices_mutex;
485 extern struct blocking_notifier_head ubi_notifiers;
486 
487 /* vtbl.c */
488 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
489 			   struct ubi_vtbl_record *vtbl_rec);
490 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
491 			    struct list_head *rename_list);
492 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
493 
494 /* vmt.c */
495 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
496 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
497 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
498 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
499 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
500 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
501 
502 /* upd.c */
503 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
504 		     long long bytes);
505 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
506 			 const void __user *buf, int count);
507 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
508 			 const struct ubi_leb_change_req *req);
509 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
510 			     const void __user *buf, int count);
511 
512 /* misc.c */
513 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
514 		      int length);
515 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
516 void ubi_calculate_reserved(struct ubi_device *ubi);
517 int ubi_check_pattern(const void *buf, uint8_t patt, int size);
518 
519 /* eba.c */
520 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
521 		      int lnum);
522 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
523 		     void *buf, int offset, int len, int check);
524 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
525 		      const void *buf, int offset, int len, int dtype);
526 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
527 			 int lnum, const void *buf, int len, int dtype,
528 			 int used_ebs);
529 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
530 			      int lnum, const void *buf, int len, int dtype);
531 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
532 		     struct ubi_vid_hdr *vid_hdr);
533 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
534 
535 /* wl.c */
536 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
537 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
538 int ubi_wl_flush(struct ubi_device *ubi);
539 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
540 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
541 void ubi_wl_close(struct ubi_device *ubi);
542 int ubi_thread(void *u);
543 
544 /* io.c */
545 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
546 		int len);
547 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
548 		 int len);
549 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
550 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
551 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
552 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
553 		       struct ubi_ec_hdr *ec_hdr, int verbose);
554 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
555 			struct ubi_ec_hdr *ec_hdr);
556 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
557 			struct ubi_vid_hdr *vid_hdr, int verbose);
558 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
559 			 struct ubi_vid_hdr *vid_hdr);
560 
561 /* build.c */
562 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
563 int ubi_detach_mtd_dev(int ubi_num, int anyway);
564 struct ubi_device *ubi_get_device(int ubi_num);
565 void ubi_put_device(struct ubi_device *ubi);
566 struct ubi_device *ubi_get_by_major(int major);
567 int ubi_major2num(int major);
568 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
569 		      int ntype);
570 int ubi_notify_all(struct ubi_device *ubi, int ntype,
571 		   struct notifier_block *nb);
572 int ubi_enumerate_volumes(struct notifier_block *nb);
573 
574 /* kapi.c */
575 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
576 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
577 			    struct ubi_volume_info *vi);
578 
579 /*
580  * ubi_rb_for_each_entry - walk an RB-tree.
581  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
582  * @pos: a pointer to RB-tree entry type to use as a loop counter
583  * @root: RB-tree's root
584  * @member: the name of the 'struct rb_node' within the RB-tree entry
585  */
586 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
587 	for (rb = rb_first(root),                                            \
588 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
589 	     rb;                                                             \
590 	     rb = rb_next(rb),                                               \
591 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
592 
593 /**
594  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
595  * @ubi: UBI device description object
596  * @gfp_flags: GFP flags to allocate with
597  *
598  * This function returns a pointer to the newly allocated and zero-filled
599  * volume identifier header object in case of success and %NULL in case of
600  * failure.
601  */
602 static inline struct ubi_vid_hdr *
603 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
604 {
605 	void *vid_hdr;
606 
607 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
608 	if (!vid_hdr)
609 		return NULL;
610 
611 	/*
612 	 * VID headers may be stored at un-aligned flash offsets, so we shift
613 	 * the pointer.
614 	 */
615 	return vid_hdr + ubi->vid_hdr_shift;
616 }
617 
618 /**
619  * ubi_free_vid_hdr - free a volume identifier header object.
620  * @ubi: UBI device description object
621  * @vid_hdr: the object to free
622  */
623 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
624 				    struct ubi_vid_hdr *vid_hdr)
625 {
626 	void *p = vid_hdr;
627 
628 	if (!p)
629 		return;
630 
631 	kfree(p - ubi->vid_hdr_shift);
632 }
633 
634 /*
635  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
636  * the beginning of the logical eraseblock, not to the beginning of the
637  * physical eraseblock.
638  */
639 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
640 				   int pnum, int offset, int len)
641 {
642 	ubi_assert(offset >= 0);
643 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
644 }
645 
646 /*
647  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
648  * the beginning of the logical eraseblock, not to the beginning of the
649  * physical eraseblock.
650  */
651 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
652 				    int pnum, int offset, int len)
653 {
654 	ubi_assert(offset >= 0);
655 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
656 }
657 
658 /**
659  * ubi_ro_mode - switch to read-only mode.
660  * @ubi: UBI device description object
661  */
662 static inline void ubi_ro_mode(struct ubi_device *ubi)
663 {
664 	if (!ubi->ro_mode) {
665 		ubi->ro_mode = 1;
666 		ubi_warn("switch to read-only mode");
667 	}
668 }
669 
670 /**
671  * vol_id2idx - get table index by volume ID.
672  * @ubi: UBI device description object
673  * @vol_id: volume ID
674  */
675 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
676 {
677 	if (vol_id >= UBI_INTERNAL_VOL_START)
678 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
679 	else
680 		return vol_id;
681 }
682 
683 /**
684  * idx2vol_id - get volume ID by table index.
685  * @ubi: UBI device description object
686  * @idx: table index
687  */
688 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
689 {
690 	if (idx >= ubi->vtbl_slots)
691 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
692 	else
693 		return idx;
694 }
695 
696 #endif /* !__UBI_UBI_H__ */
697