xref: /linux/drivers/mtd/ubi/ubi.h (revision 02bf6cc72cc2a6258411ddf1649f33a65fc9a06e)
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/notifier.h>
40 #include <linux/mtd/mtd.h>
41 #include <linux/mtd/ubi.h>
42 
43 #include "ubi-media.h"
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 				  __func__, ##__VA_ARGS__)
58 /* UBI error messages */
59 #define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
60 				 __func__, ##__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  * 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 /*
85  * Error codes returned by the I/O sub-system.
86  *
87  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
88  *                   %0xFF bytes
89  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
90  *                  valid erase counter header, and the rest are %0xFF bytes
91  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
92  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
93  *                     CRC)
94  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
95  */
96 enum {
97 	UBI_IO_PEB_EMPTY = 1,
98 	UBI_IO_PEB_FREE,
99 	UBI_IO_BAD_EC_HDR,
100 	UBI_IO_BAD_VID_HDR,
101 	UBI_IO_BITFLIPS
102 };
103 
104 /*
105  * Return codes of the 'ubi_eba_copy_leb()' function.
106  *
107  * MOVE_CANCEL_RACE: canceled because the volume is being deleted, the source
108  *                   PEB was put meanwhile, or there is I/O on the source PEB
109  * MOVE_SOURCE_RD_ERR: canceled because there was a read error from the source
110  *                     PEB
111  * MOVE_TARGET_RD_ERR: canceled because there was a read error from the target
112  *                     PEB
113  * MOVE_TARGET_WR_ERR: canceled because there was a write error to the target
114  *                     PEB
115  * MOVE_CANCEL_BITFLIPS: canceled because a bit-flip was detected in the
116  *                       target PEB
117  */
118 enum {
119 	MOVE_CANCEL_RACE = 1,
120 	MOVE_SOURCE_RD_ERR,
121 	MOVE_TARGET_RD_ERR,
122 	MOVE_TARGET_WR_ERR,
123 	MOVE_CANCEL_BITFLIPS,
124 };
125 
126 /**
127  * struct ubi_wl_entry - wear-leveling entry.
128  * @u.rb: link in the corresponding (free/used) RB-tree
129  * @u.list: link in the protection queue
130  * @ec: erase counter
131  * @pnum: physical eraseblock number
132  *
133  * This data structure is used in the WL sub-system. Each physical eraseblock
134  * has a corresponding &struct wl_entry object which may be kept in different
135  * RB-trees. See WL sub-system for details.
136  */
137 struct ubi_wl_entry {
138 	union {
139 		struct rb_node rb;
140 		struct list_head list;
141 	} u;
142 	int ec;
143 	int pnum;
144 };
145 
146 /**
147  * struct ubi_ltree_entry - an entry in the lock tree.
148  * @rb: links RB-tree nodes
149  * @vol_id: volume ID of the locked logical eraseblock
150  * @lnum: locked logical eraseblock number
151  * @users: how many tasks are using this logical eraseblock or wait for it
152  * @mutex: read/write mutex to implement read/write access serialization to
153  *         the (@vol_id, @lnum) logical eraseblock
154  *
155  * This data structure is used in the EBA sub-system to implement per-LEB
156  * locking. When a logical eraseblock is being locked - corresponding
157  * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
158  * See EBA sub-system for details.
159  */
160 struct ubi_ltree_entry {
161 	struct rb_node rb;
162 	int vol_id;
163 	int lnum;
164 	int users;
165 	struct rw_semaphore mutex;
166 };
167 
168 /**
169  * struct ubi_rename_entry - volume re-name description data structure.
170  * @new_name_len: new volume name length
171  * @new_name: new volume name
172  * @remove: if not zero, this volume should be removed, not re-named
173  * @desc: descriptor of the volume
174  * @list: links re-name entries into a list
175  *
176  * This data structure is utilized in the multiple volume re-name code. Namely,
177  * UBI first creates a list of &struct ubi_rename_entry objects from the
178  * &struct ubi_rnvol_req request object, and then utilizes this list to do all
179  * the job.
180  */
181 struct ubi_rename_entry {
182 	int new_name_len;
183 	char new_name[UBI_VOL_NAME_MAX + 1];
184 	int remove;
185 	struct ubi_volume_desc *desc;
186 	struct list_head list;
187 };
188 
189 struct ubi_volume_desc;
190 
191 /**
192  * struct ubi_volume - UBI volume description data structure.
193  * @dev: device object to make use of the the Linux device model
194  * @cdev: character device object to create character device
195  * @ubi: reference to the UBI device description object
196  * @vol_id: volume ID
197  * @ref_count: volume reference count
198  * @readers: number of users holding this volume in read-only mode
199  * @writers: number of users holding this volume in read-write mode
200  * @exclusive: whether somebody holds this volume in exclusive mode
201  *
202  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
203  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
204  * @usable_leb_size: logical eraseblock size without padding
205  * @used_ebs: how many logical eraseblocks in this volume contain data
206  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
207  * @used_bytes: how many bytes of data this volume contains
208  * @alignment: volume alignment
209  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
210  *            satisfy the requested alignment
211  * @name_len: volume name length
212  * @name: volume name
213  *
214  * @upd_ebs: how many eraseblocks are expected to be updated
215  * @ch_lnum: LEB number which is being changing by the atomic LEB change
216  *           operation
217  * @ch_dtype: data persistency type which is being changing by the atomic LEB
218  *            change operation
219  * @upd_bytes: how many bytes are expected to be received for volume update or
220  *             atomic LEB change
221  * @upd_received: how many bytes were already received for volume update or
222  *                atomic LEB change
223  * @upd_buf: update buffer which is used to collect update data or data for
224  *           atomic LEB change
225  *
226  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
227  * @checked: %1 if this static volume was checked
228  * @corrupted: %1 if the volume is corrupted (static volumes only)
229  * @upd_marker: %1 if the update marker is set for this volume
230  * @updating: %1 if the volume is being updated
231  * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
232  * @direct_writes: %1 if direct writes are enabled for this volume
233  *
234  * The @corrupted field indicates that the volume's contents is corrupted.
235  * Since UBI protects only static volumes, this field is not relevant to
236  * dynamic volumes - it is user's responsibility to assure their data
237  * integrity.
238  *
239  * The @upd_marker flag indicates that this volume is either being updated at
240  * the moment or is damaged because of an unclean reboot.
241  */
242 struct ubi_volume {
243 	struct device dev;
244 	struct cdev cdev;
245 	struct ubi_device *ubi;
246 	int vol_id;
247 	int ref_count;
248 	int readers;
249 	int writers;
250 	int exclusive;
251 
252 	int reserved_pebs;
253 	int vol_type;
254 	int usable_leb_size;
255 	int used_ebs;
256 	int last_eb_bytes;
257 	long long used_bytes;
258 	int alignment;
259 	int data_pad;
260 	int name_len;
261 	char name[UBI_VOL_NAME_MAX + 1];
262 
263 	int upd_ebs;
264 	int ch_lnum;
265 	int ch_dtype;
266 	long long upd_bytes;
267 	long long upd_received;
268 	void *upd_buf;
269 
270 	int *eba_tbl;
271 	unsigned int checked:1;
272 	unsigned int corrupted:1;
273 	unsigned int upd_marker:1;
274 	unsigned int updating:1;
275 	unsigned int changing_leb:1;
276 	unsigned int direct_writes:1;
277 };
278 
279 /**
280  * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
281  * @vol: reference to the corresponding volume description object
282  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
283  */
284 struct ubi_volume_desc {
285 	struct ubi_volume *vol;
286 	int mode;
287 };
288 
289 struct ubi_wl_entry;
290 
291 /**
292  * struct ubi_device - UBI device description structure
293  * @dev: UBI device object to use the the Linux device model
294  * @cdev: character device object to create character device
295  * @ubi_num: UBI device number
296  * @ubi_name: UBI device name
297  * @vol_count: number of volumes in this UBI device
298  * @volumes: volumes of this UBI device
299  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
300  *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
301  *                @vol->readers, @vol->writers, @vol->exclusive,
302  *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
303  * @ref_count: count of references on the UBI device
304  * @image_seq: image sequence number recorded on EC headers
305  *
306  * @rsvd_pebs: count of reserved physical eraseblocks
307  * @avail_pebs: count of available physical eraseblocks
308  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
309  *                 handling
310  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
311  *
312  * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
313  *                     of UBI initialization
314  * @vtbl_slots: how many slots are available in the volume table
315  * @vtbl_size: size of the volume table in bytes
316  * @vtbl: in-RAM volume table copy
317  * @device_mutex: protects on-flash volume table and serializes volume
318  *                creation, deletion, update, re-size, re-name and set
319  *                property
320  *
321  * @max_ec: current highest erase counter value
322  * @mean_ec: current mean erase counter value
323  *
324  * @global_sqnum: global sequence number
325  * @ltree_lock: protects the lock tree and @global_sqnum
326  * @ltree: the lock tree
327  * @alc_mutex: serializes "atomic LEB change" operations
328  *
329  * @used: RB-tree of used physical eraseblocks
330  * @erroneous: RB-tree of erroneous used physical eraseblocks
331  * @free: RB-tree of free physical eraseblocks
332  * @scrub: RB-tree of physical eraseblocks which need scrubbing
333  * @pq: protection queue (contain physical eraseblocks which are temporarily
334  *      protected from the wear-leveling worker)
335  * @pq_head: protection queue head
336  * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
337  * 	     @move_to, @move_to_put @erase_pending, @wl_scheduled, @works,
338  * 	     @erroneous, and @erroneous_peb_count fields
339  * @move_mutex: serializes eraseblock moves
340  * @work_sem: synchronizes the WL worker with use tasks
341  * @wl_scheduled: non-zero if the wear-leveling was scheduled
342  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
343  *             physical eraseblock
344  * @move_from: physical eraseblock from where the data is being moved
345  * @move_to: physical eraseblock where the data is being moved to
346  * @move_to_put: if the "to" PEB was put
347  * @works: list of pending works
348  * @works_count: count of pending works
349  * @bgt_thread: background thread description object
350  * @thread_enabled: if the background thread is enabled
351  * @bgt_name: background thread name
352  * @reboot_notifier: notifier to terminate background thread before rebooting
353  *
354  * @flash_size: underlying MTD device size (in bytes)
355  * @peb_count: count of physical eraseblocks on the MTD device
356  * @peb_size: physical eraseblock size
357  * @bad_peb_count: count of bad physical eraseblocks
358  * @good_peb_count: count of good physical eraseblocks
359  * @erroneous_peb_count: count of erroneous physical eraseblocks in @erroneous
360  * @max_erroneous: maximum allowed amount of erroneous physical eraseblocks
361  * @min_io_size: minimal input/output unit size of the underlying MTD device
362  * @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
363  * @ro_mode: if the UBI device is in read-only mode
364  * @leb_size: logical eraseblock size
365  * @leb_start: starting offset of logical eraseblocks within physical
366  *             eraseblocks
367  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
368  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
369  * @vid_hdr_offset: starting offset of the volume identifier header (might be
370  *                  unaligned)
371  * @vid_hdr_aloffset: starting offset of the VID header aligned to
372  * @hdrs_min_io_size
373  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
374  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
375  *               not
376  * @nor_flash: non-zero if working on top of NOR flash
377  * @mtd: MTD device descriptor
378  *
379  * @peb_buf1: a buffer of PEB size used for different purposes
380  * @peb_buf2: another buffer of PEB size used for different purposes
381  * @buf_mutex: protects @peb_buf1 and @peb_buf2
382  * @ckvol_mutex: serializes static volume checking when opening
383  * @dbg_peb_buf: buffer of PEB size used for debugging
384  * @dbg_buf_mutex: protects @dbg_peb_buf
385  */
386 struct ubi_device {
387 	struct cdev cdev;
388 	struct device dev;
389 	int ubi_num;
390 	char ubi_name[sizeof(UBI_NAME_STR)+5];
391 	int vol_count;
392 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
393 	spinlock_t volumes_lock;
394 	int ref_count;
395 	int image_seq;
396 
397 	int rsvd_pebs;
398 	int avail_pebs;
399 	int beb_rsvd_pebs;
400 	int beb_rsvd_level;
401 
402 	int autoresize_vol_id;
403 	int vtbl_slots;
404 	int vtbl_size;
405 	struct ubi_vtbl_record *vtbl;
406 	struct mutex device_mutex;
407 
408 	int max_ec;
409 	/* Note, mean_ec is not updated run-time - should be fixed */
410 	int mean_ec;
411 
412 	/* EBA sub-system's stuff */
413 	unsigned long long global_sqnum;
414 	spinlock_t ltree_lock;
415 	struct rb_root ltree;
416 	struct mutex alc_mutex;
417 
418 	/* Wear-leveling sub-system's stuff */
419 	struct rb_root used;
420 	struct rb_root erroneous;
421 	struct rb_root free;
422 	struct rb_root scrub;
423 	struct list_head pq[UBI_PROT_QUEUE_LEN];
424 	int pq_head;
425 	spinlock_t wl_lock;
426 	struct mutex move_mutex;
427 	struct rw_semaphore work_sem;
428 	int wl_scheduled;
429 	struct ubi_wl_entry **lookuptbl;
430 	struct ubi_wl_entry *move_from;
431 	struct ubi_wl_entry *move_to;
432 	int move_to_put;
433 	struct list_head works;
434 	int works_count;
435 	struct task_struct *bgt_thread;
436 	int thread_enabled;
437 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
438 	struct notifier_block reboot_notifier;
439 
440 	/* I/O sub-system's stuff */
441 	long long flash_size;
442 	int peb_count;
443 	int peb_size;
444 	int bad_peb_count;
445 	int good_peb_count;
446 	int erroneous_peb_count;
447 	int max_erroneous;
448 	int min_io_size;
449 	int hdrs_min_io_size;
450 	int ro_mode;
451 	int leb_size;
452 	int leb_start;
453 	int ec_hdr_alsize;
454 	int vid_hdr_alsize;
455 	int vid_hdr_offset;
456 	int vid_hdr_aloffset;
457 	int vid_hdr_shift;
458 	unsigned int bad_allowed:1;
459 	unsigned int nor_flash:1;
460 	struct mtd_info *mtd;
461 
462 	void *peb_buf1;
463 	void *peb_buf2;
464 	struct mutex buf_mutex;
465 	struct mutex ckvol_mutex;
466 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
467 	void *dbg_peb_buf;
468 	struct mutex dbg_buf_mutex;
469 #endif
470 };
471 
472 extern struct kmem_cache *ubi_wl_entry_slab;
473 extern const struct file_operations ubi_ctrl_cdev_operations;
474 extern const struct file_operations ubi_cdev_operations;
475 extern const struct file_operations ubi_vol_cdev_operations;
476 extern struct class *ubi_class;
477 extern struct mutex ubi_devices_mutex;
478 extern struct blocking_notifier_head ubi_notifiers;
479 
480 /* vtbl.c */
481 int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
482 			   struct ubi_vtbl_record *vtbl_rec);
483 int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
484 			    struct list_head *rename_list);
485 int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
486 
487 /* vmt.c */
488 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
489 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
490 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
491 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
492 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
493 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
494 
495 /* upd.c */
496 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
497 		     long long bytes);
498 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
499 			 const void __user *buf, int count);
500 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
501 			 const struct ubi_leb_change_req *req);
502 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
503 			     const void __user *buf, int count);
504 
505 /* misc.c */
506 int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
507 		      int length);
508 int ubi_check_volume(struct ubi_device *ubi, int vol_id);
509 void ubi_calculate_reserved(struct ubi_device *ubi);
510 
511 /* eba.c */
512 int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
513 		      int lnum);
514 int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
515 		     void *buf, int offset, int len, int check);
516 int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
517 		      const void *buf, int offset, int len, int dtype);
518 int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
519 			 int lnum, const void *buf, int len, int dtype,
520 			 int used_ebs);
521 int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
522 			      int lnum, const void *buf, int len, int dtype);
523 int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
524 		     struct ubi_vid_hdr *vid_hdr);
525 int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
526 
527 /* wl.c */
528 int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
529 int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
530 int ubi_wl_flush(struct ubi_device *ubi);
531 int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
532 int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
533 void ubi_wl_close(struct ubi_device *ubi);
534 int ubi_thread(void *u);
535 
536 /* io.c */
537 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
538 		int len);
539 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
540 		 int len);
541 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
542 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
543 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
544 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
545 		       struct ubi_ec_hdr *ec_hdr, int verbose);
546 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
547 			struct ubi_ec_hdr *ec_hdr);
548 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
549 			struct ubi_vid_hdr *vid_hdr, int verbose);
550 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
551 			 struct ubi_vid_hdr *vid_hdr);
552 
553 /* build.c */
554 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
555 int ubi_detach_mtd_dev(int ubi_num, int anyway);
556 struct ubi_device *ubi_get_device(int ubi_num);
557 void ubi_put_device(struct ubi_device *ubi);
558 struct ubi_device *ubi_get_by_major(int major);
559 int ubi_major2num(int major);
560 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol,
561 		      int ntype);
562 int ubi_notify_all(struct ubi_device *ubi, int ntype,
563 		   struct notifier_block *nb);
564 int ubi_enumerate_volumes(struct notifier_block *nb);
565 
566 /* kapi.c */
567 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di);
568 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
569 			    struct ubi_volume_info *vi);
570 
571 /*
572  * ubi_rb_for_each_entry - walk an RB-tree.
573  * @rb: a pointer to type 'struct rb_node' to use as a loop counter
574  * @pos: a pointer to RB-tree entry type to use as a loop counter
575  * @root: RB-tree's root
576  * @member: the name of the 'struct rb_node' within the RB-tree entry
577  */
578 #define ubi_rb_for_each_entry(rb, pos, root, member)                         \
579 	for (rb = rb_first(root),                                            \
580 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL);     \
581 	     rb;                                                             \
582 	     rb = rb_next(rb),                                               \
583 	     pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
584 
585 /**
586  * ubi_zalloc_vid_hdr - allocate a volume identifier header object.
587  * @ubi: UBI device description object
588  * @gfp_flags: GFP flags to allocate with
589  *
590  * This function returns a pointer to the newly allocated and zero-filled
591  * volume identifier header object in case of success and %NULL in case of
592  * failure.
593  */
594 static inline struct ubi_vid_hdr *
595 ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
596 {
597 	void *vid_hdr;
598 
599 	vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
600 	if (!vid_hdr)
601 		return NULL;
602 
603 	/*
604 	 * VID headers may be stored at un-aligned flash offsets, so we shift
605 	 * the pointer.
606 	 */
607 	return vid_hdr + ubi->vid_hdr_shift;
608 }
609 
610 /**
611  * ubi_free_vid_hdr - free a volume identifier header object.
612  * @ubi: UBI device description object
613  * @vid_hdr: the object to free
614  */
615 static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
616 				    struct ubi_vid_hdr *vid_hdr)
617 {
618 	void *p = vid_hdr;
619 
620 	if (!p)
621 		return;
622 
623 	kfree(p - ubi->vid_hdr_shift);
624 }
625 
626 /*
627  * This function is equivalent to 'ubi_io_read()', but @offset is relative to
628  * the beginning of the logical eraseblock, not to the beginning of the
629  * physical eraseblock.
630  */
631 static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
632 				   int pnum, int offset, int len)
633 {
634 	ubi_assert(offset >= 0);
635 	return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
636 }
637 
638 /*
639  * This function is equivalent to 'ubi_io_write()', but @offset is relative to
640  * the beginning of the logical eraseblock, not to the beginning of the
641  * physical eraseblock.
642  */
643 static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
644 				    int pnum, int offset, int len)
645 {
646 	ubi_assert(offset >= 0);
647 	return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
648 }
649 
650 /**
651  * ubi_ro_mode - switch to read-only mode.
652  * @ubi: UBI device description object
653  */
654 static inline void ubi_ro_mode(struct ubi_device *ubi)
655 {
656 	if (!ubi->ro_mode) {
657 		ubi->ro_mode = 1;
658 		ubi_warn("switch to read-only mode");
659 	}
660 }
661 
662 /**
663  * vol_id2idx - get table index by volume ID.
664  * @ubi: UBI device description object
665  * @vol_id: volume ID
666  */
667 static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
668 {
669 	if (vol_id >= UBI_INTERNAL_VOL_START)
670 		return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
671 	else
672 		return vol_id;
673 }
674 
675 /**
676  * idx2vol_id - get volume ID by table index.
677  * @ubi: UBI device description object
678  * @idx: table index
679  */
680 static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
681 {
682 	if (idx >= ubi->vtbl_slots)
683 		return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
684 	else
685 		return idx;
686 }
687 
688 #endif /* !__UBI_UBI_H__ */
689