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linux/drivers/mtd/ubi/ubi.h
Artem Bityutskiy 896c0c06aa UBI: use bit-fields 
Save 12 bytes of RAM per volume by using bit-fields instead of integers.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
2008-01-25 16:41:24 +02:00

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/*
* Copyright (c) International Business Machines Corp., 2006
* Copyright (c) Nokia Corporation, 2006, 2007
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Artem Bityutskiy (Битюцкий Артём)
*/
#ifndef __UBI_UBI_H__
#define __UBI_UBI_H__
#include <linux/init.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include <linux/mtd/mtd.h>
#include <mtd/ubi-header.h>
#include <linux/mtd/ubi.h>
#include "scan.h"
#include "debug.h"
/* Maximum number of supported UBI devices */
#define UBI_MAX_DEVICES 32
/* UBI name used for character devices, sysfs, etc */
#define UBI_NAME_STR "ubi"
/* Normal UBI messages */
#define ubi_msg(fmt, ...) printk(KERN_NOTICE "UBI: " fmt "\n", ##__VA_ARGS__)
/* UBI warning messages */
#define ubi_warn(fmt, ...) printk(KERN_WARNING "UBI warning: %s: " fmt "\n", \
__FUNCTION__, ##__VA_ARGS__)
/* UBI error messages */
#define ubi_err(fmt, ...) printk(KERN_ERR "UBI error: %s: " fmt "\n", \
__FUNCTION__, ##__VA_ARGS__)
/* Lowest number PEBs reserved for bad PEB handling */
#define MIN_RESEVED_PEBS 2
/* Background thread name pattern */
#define UBI_BGT_NAME_PATTERN "ubi_bgt%dd"
/* This marker in the EBA table means that the LEB is um-mapped */
#define UBI_LEB_UNMAPPED -1
/*
* In case of errors, UBI tries to repeat the operation several times before
* returning error. The below constant defines how many times UBI re-tries.
*/
#define UBI_IO_RETRIES 3
/*
* Error codes returned by the I/O unit.
*
* UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
* 0xFF bytes
* UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
* valid erase counter header, and the rest are %0xFF bytes
* UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
* UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
* CRC)
* UBI_IO_BITFLIPS: bit-flips were detected and corrected
*/
enum {
UBI_IO_PEB_EMPTY = 1,
UBI_IO_PEB_FREE,
UBI_IO_BAD_EC_HDR,
UBI_IO_BAD_VID_HDR,
UBI_IO_BITFLIPS
};
/**
* struct ubi_wl_entry - wear-leveling entry.
* @rb: link in the corresponding RB-tree
* @ec: erase counter
* @pnum: physical eraseblock number
*
* This data structure is used in the WL unit. Each physical eraseblock has a
* corresponding &struct wl_entry object which may be kept in different
* RB-trees. See WL unit for details.
*/
struct ubi_wl_entry {
struct rb_node rb;
int ec;
int pnum;
};
/**
* struct ubi_ltree_entry - an entry in the lock tree.
* @rb: links RB-tree nodes
* @vol_id: volume ID of the locked logical eraseblock
* @lnum: locked logical eraseblock number
* @users: how many tasks are using this logical eraseblock or wait for it
* @mutex: read/write mutex to implement read/write access serialization to
* the (@vol_id, @lnum) logical eraseblock
*
* This data structure is used in the EBA unit to implement per-LEB locking.
* When a logical eraseblock is being locked - corresponding
* &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
* See EBA unit for details.
*/
struct ubi_ltree_entry {
struct rb_node rb;
int vol_id;
int lnum;
int users;
struct rw_semaphore mutex;
};
struct ubi_volume_desc;
/**
* struct ubi_volume - UBI volume description data structure.
* @dev: device object to make use of the the Linux device model
* @cdev: character device object to create character device
* @ubi: reference to the UBI device description object
* @vol_id: volume ID
* @ref_count: volume reference count
* @readers: number of users holding this volume in read-only mode
* @writers: number of users holding this volume in read-write mode
* @exclusive: whether somebody holds this volume in exclusive mode
*
* @reserved_pebs: how many physical eraseblocks are reserved for this volume
* @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
* @usable_leb_size: logical eraseblock size without padding
* @used_ebs: how many logical eraseblocks in this volume contain data
* @last_eb_bytes: how many bytes are stored in the last logical eraseblock
* @used_bytes: how many bytes of data this volume contains
* @alignment: volume alignment
* @data_pad: how many bytes are not used at the end of physical eraseblocks to
* satisfy the requested alignment
* @name_len: volume name length
* @name: volume name
*
* @upd_ebs: how many eraseblocks are expected to be updated
* @upd_bytes: how many bytes are expected to be received
* @upd_received: how many update bytes were already received
* @upd_buf: update buffer which is used to collect update data
*
* @eba_tbl: EBA table of this volume (LEB->PEB mapping)
* @checked: %1 if this static volume was checked
* @corrupted: %1 if the volume is corrupted (static volumes only)
* @upd_marker: %1 if the update marker is set for this volume
* @updating: %1 if the volume is being updated
*
* @gluebi_desc: gluebi UBI volume descriptor
* @gluebi_refcount: reference count of the gluebi MTD device
* @gluebi_mtd: MTD device description object of the gluebi MTD device
*
* The @corrupted field indicates that the volume's contents is corrupted.
* Since UBI protects only static volumes, this field is not relevant to
* dynamic volumes - it is user's responsibility to assure their data
* integrity.
*
* The @upd_marker flag indicates that this volume is either being updated at
* the moment or is damaged because of an unclean reboot.
*/
struct ubi_volume {
struct device dev;
struct cdev cdev;
struct ubi_device *ubi;
int vol_id;
int ref_count;
int readers;
int writers;
int exclusive;
int reserved_pebs;
int vol_type;
int usable_leb_size;
int used_ebs;
int last_eb_bytes;
long long used_bytes;
int alignment;
int data_pad;
int name_len;
char name[UBI_VOL_NAME_MAX+1];
int upd_ebs;
long long upd_bytes;
long long upd_received;
void *upd_buf;
int *eba_tbl;
int checked:1;
int corrupted:1;
int upd_marker:1;
int updating:1;
#ifdef CONFIG_MTD_UBI_GLUEBI
/* Gluebi-related stuff may be compiled out */
struct ubi_volume_desc *gluebi_desc;
int gluebi_refcount;
struct mtd_info gluebi_mtd;
#endif
};
/**
* struct ubi_volume_desc - descriptor of the UBI volume returned when it is
* opened.
* @vol: reference to the corresponding volume description object
* @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
*/
struct ubi_volume_desc {
struct ubi_volume *vol;
int mode;
};
struct ubi_wl_entry;
/**
* struct ubi_device - UBI device description structure
* @dev: UBI device object to use the the Linux device model
* @cdev: character device object to create character device
* @ubi_num: UBI device number
* @ubi_name: UBI device name
* @vol_count: number of volumes in this UBI device
* @volumes: volumes of this UBI device
* @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
* @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
* @vol->readers, @vol->writers, @vol->exclusive,
* @vol->ref_count, @vol->mapping and @vol->eba_tbl.
* @ref_count: count of references on the UBI device
*
* @rsvd_pebs: count of reserved physical eraseblocks
* @avail_pebs: count of available physical eraseblocks
* @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
* handling
* @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
*
* @vtbl_slots: how many slots are available in the volume table
* @vtbl_size: size of the volume table in bytes
* @vtbl: in-RAM volume table copy
* @volumes_mutex: protects on-flash volume table and serializes volume
* changes, like creation, deletion, update, resize
*
* @max_ec: current highest erase counter value
* @mean_ec: current mean erase counter value
*
* @global_sqnum: global sequence number
* @ltree_lock: protects the lock tree and @global_sqnum
* @ltree: the lock tree
* @alc_mutex: serializes "atomic LEB change" operations
*
* @used: RB-tree of used physical eraseblocks
* @free: RB-tree of free physical eraseblocks
* @scrub: RB-tree of physical eraseblocks which need scrubbing
* @prot: protection trees
* @prot.pnum: protection tree indexed by physical eraseblock numbers
* @prot.aec: protection tree indexed by absolute erase counter value
* @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
* @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
* fields
* @move_mutex: serializes eraseblock moves
* @wl_scheduled: non-zero if the wear-leveling was scheduled
* @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
* physical eraseblock
* @abs_ec: absolute erase counter
* @move_from: physical eraseblock from where the data is being moved
* @move_to: physical eraseblock where the data is being moved to
* @move_to_put: if the "to" PEB was put
* @works: list of pending works
* @works_count: count of pending works
* @bgt_thread: background thread description object
* @thread_enabled: if the background thread is enabled
* @bgt_name: background thread name
*
* @flash_size: underlying MTD device size (in bytes)
* @peb_count: count of physical eraseblocks on the MTD device
* @peb_size: physical eraseblock size
* @bad_peb_count: count of bad physical eraseblocks
* @good_peb_count: count of good physical eraseblocks
* @min_io_size: minimal input/output unit size of the underlying MTD device
* @hdrs_min_io_size: minimal I/O unit size used for VID and EC headers
* @ro_mode: if the UBI device is in read-only mode
* @leb_size: logical eraseblock size
* @leb_start: starting offset of logical eraseblocks within physical
* eraseblocks
* @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
* @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
* @vid_hdr_offset: starting offset of the volume identifier header (might be
* unaligned)
* @vid_hdr_aloffset: starting offset of the VID header aligned to
* @hdrs_min_io_size
* @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
* @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
* not
* @mtd: MTD device descriptor
*
* @peb_buf1: a buffer of PEB size used for different purposes
* @peb_buf2: another buffer of PEB size used for different purposes
* @buf_mutex: proptects @peb_buf1 and @peb_buf2
* @dbg_peb_buf: buffer of PEB size used for debugging
* @dbg_buf_mutex: proptects @dbg_peb_buf
*/
struct ubi_device {
struct cdev cdev;
struct device dev;
int ubi_num;
char ubi_name[sizeof(UBI_NAME_STR)+5];
int vol_count;
struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
spinlock_t volumes_lock;
int ref_count;
int rsvd_pebs;
int avail_pebs;
int beb_rsvd_pebs;
int beb_rsvd_level;
int vtbl_slots;
int vtbl_size;
struct ubi_vtbl_record *vtbl;
struct mutex volumes_mutex;
int max_ec;
int mean_ec;
/* EBA unit's stuff */
unsigned long long global_sqnum;
spinlock_t ltree_lock;
struct rb_root ltree;
struct mutex alc_mutex;
/* Wear-leveling unit's stuff */
struct rb_root used;
struct rb_root free;
struct rb_root scrub;
struct {
struct rb_root pnum;
struct rb_root aec;
} prot;
spinlock_t wl_lock;
struct mutex move_mutex;
struct rw_semaphore work_sem;
int wl_scheduled;
struct ubi_wl_entry **lookuptbl;
unsigned long long abs_ec;
struct ubi_wl_entry *move_from;
struct ubi_wl_entry *move_to;
int move_to_put;
struct list_head works;
int works_count;
struct task_struct *bgt_thread;
int thread_enabled;
char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
/* I/O unit's stuff */
long long flash_size;
int peb_count;
int peb_size;
int bad_peb_count;
int good_peb_count;
int min_io_size;
int hdrs_min_io_size;
int ro_mode;
int leb_size;
int leb_start;
int ec_hdr_alsize;
int vid_hdr_alsize;
int vid_hdr_offset;
int vid_hdr_aloffset;
int vid_hdr_shift;
int bad_allowed;
struct mtd_info *mtd;
void *peb_buf1;
void *peb_buf2;
struct mutex buf_mutex;
struct mutex ckvol_mutex;
#ifdef CONFIG_MTD_UBI_DEBUG
void *dbg_peb_buf;
struct mutex dbg_buf_mutex;
#endif
};
extern struct kmem_cache *ubi_wl_entry_slab;
extern struct file_operations ubi_ctrl_cdev_operations;
extern struct file_operations ubi_cdev_operations;
extern struct file_operations ubi_vol_cdev_operations;
extern struct class *ubi_class;
extern struct mutex ubi_devices_mutex;
/* vtbl.c */
int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
struct ubi_vtbl_record *vtbl_rec);
int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
/* vmt.c */
int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
int ubi_remove_volume(struct ubi_volume_desc *desc);
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
/* upd.c */
int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
const void __user *buf, int count);
/* misc.c */
int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
int ubi_check_volume(struct ubi_device *ubi, int vol_id);
void ubi_calculate_reserved(struct ubi_device *ubi);
/* gluebi.c */
#ifdef CONFIG_MTD_UBI_GLUEBI
int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol);
int ubi_destroy_gluebi(struct ubi_volume *vol);
void ubi_gluebi_updated(struct ubi_volume *vol);
#else
#define ubi_create_gluebi(ubi, vol) 0
#define ubi_destroy_gluebi(vol) 0
#define ubi_gluebi_updated(vol)
#endif
/* eba.c */
int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum);
int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
void *buf, int offset, int len, int check);
int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
const void *buf, int offset, int len, int dtype);
int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum, const void *buf, int len, int dtype,
int used_ebs);
int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
int lnum, const void *buf, int len, int dtype);
int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
struct ubi_vid_hdr *vid_hdr);
int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
void ubi_eba_close(const struct ubi_device *ubi);
/* wl.c */
int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture);
int ubi_wl_flush(struct ubi_device *ubi);
int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
void ubi_wl_close(struct ubi_device *ubi);
int ubi_thread(void *u);
/* io.c */
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
int len);
int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
int len);
int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture);
int ubi_io_is_bad(const struct ubi_device *ubi, int pnum);
int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum);
int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
struct ubi_ec_hdr *ec_hdr, int verbose);
int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
struct ubi_ec_hdr *ec_hdr);
int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
struct ubi_vid_hdr *vid_hdr, int verbose);
int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
struct ubi_vid_hdr *vid_hdr);
/* build.c */
int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
int ubi_detach_mtd_dev(int ubi_num, int anyway);
struct ubi_device *ubi_get_device(int ubi_num);
void ubi_put_device(struct ubi_device *ubi);
struct ubi_device *ubi_get_by_major(int major);
int ubi_major2num(int major);
/*
* ubi_rb_for_each_entry - walk an RB-tree.
* @rb: a pointer to type 'struct rb_node' to to use as a loop counter
* @pos: a pointer to RB-tree entry type to use as a loop counter
* @root: RB-tree's root
* @member: the name of the 'struct rb_node' within the RB-tree entry
*/
#define ubi_rb_for_each_entry(rb, pos, root, member) \
for (rb = rb_first(root), \
pos = (rb ? container_of(rb, typeof(*pos), member) : NULL); \
rb; \
rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
/**
* ubi_zalloc_vid_hdr - allocate a volume identifier header object.
* @ubi: UBI device description object
* @gfp_flags: GFP flags to allocate with
*
* This function returns a pointer to the newly allocated and zero-filled
* volume identifier header object in case of success and %NULL in case of
* failure.
*/
static inline struct ubi_vid_hdr *
ubi_zalloc_vid_hdr(const struct ubi_device *ubi, gfp_t gfp_flags)
{
void *vid_hdr;
vid_hdr = kzalloc(ubi->vid_hdr_alsize, gfp_flags);
if (!vid_hdr)
return NULL;
/*
* VID headers may be stored at un-aligned flash offsets, so we shift
* the pointer.
*/
return vid_hdr + ubi->vid_hdr_shift;
}
/**
* ubi_free_vid_hdr - free a volume identifier header object.
* @ubi: UBI device description object
* @vid_hdr: the object to free
*/
static inline void ubi_free_vid_hdr(const struct ubi_device *ubi,
struct ubi_vid_hdr *vid_hdr)
{
void *p = vid_hdr;
if (!p)
return;
kfree(p - ubi->vid_hdr_shift);
}
/*
* This function is equivalent to 'ubi_io_read()', but @offset is relative to
* the beginning of the logical eraseblock, not to the beginning of the
* physical eraseblock.
*/
static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
int pnum, int offset, int len)
{
ubi_assert(offset >= 0);
return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
}
/*
* This function is equivalent to 'ubi_io_write()', but @offset is relative to
* the beginning of the logical eraseblock, not to the beginning of the
* physical eraseblock.
*/
static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
int pnum, int offset, int len)
{
ubi_assert(offset >= 0);
return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
}
/**
* ubi_ro_mode - switch to read-only mode.
* @ubi: UBI device description object
*/
static inline void ubi_ro_mode(struct ubi_device *ubi)
{
if (!ubi->ro_mode) {
ubi->ro_mode = 1;
ubi_warn("switch to read-only mode");
}
}
/**
* vol_id2idx - get table index by volume ID.
* @ubi: UBI device description object
* @vol_id: volume ID
*/
static inline int vol_id2idx(const struct ubi_device *ubi, int vol_id)
{
if (vol_id >= UBI_INTERNAL_VOL_START)
return vol_id - UBI_INTERNAL_VOL_START + ubi->vtbl_slots;
else
return vol_id;
}
/**
* idx2vol_id - get volume ID by table index.
* @ubi: UBI device description object
* @idx: table index
*/
static inline int idx2vol_id(const struct ubi_device *ubi, int idx)
{
if (idx >= ubi->vtbl_slots)
return idx - ubi->vtbl_slots + UBI_INTERNAL_VOL_START;
else
return idx;
}
#endif /* !__UBI_UBI_H__ */
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