mtd.h

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/*
 * Copyright © 1999-2010 David Woodhouse <[email protected]> et al.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifndef __MTD_MTD_H__
#define __MTD_MTD_H__

#include <linux/types.h>
#include <linux/uio.h>
#include <linux/notifier.h>
#include <linux/device.h>

#include <mtd/mtd-abi.h>

#include <asm/div64.h>

#define MTD_CHAR_MAJOR 90
#define MTD_BLOCK_MAJOR 31

#define MTD_ERASE_PENDING   0x01
#define MTD_ERASING     0x02
#define MTD_ERASE_SUSPEND   0x04
#define MTD_ERASE_DONE      0x08
#define MTD_ERASE_FAILED    0x10

#define MTD_FAIL_ADDR_UNKNOWN -1LL

/*
 * If the erase fails, fail_addr might indicate exactly which block failed. If
 * fail_addr = MTD_FAIL_ADDR_UNKNOWN, the failure was not at the device level
 * or was not specific to any particular block.
 */
struct erase_info {
    struct mtd_info *mtd;
    uint64_t addr;
    uint64_t len;
    uint64_t fail_addr;
    u_long time;
    u_long retries;
    unsigned dev;
    unsigned cell;
    void (*callback) (struct erase_info *self);
    u_long priv;
    u_char state;
    struct erase_info *next;
};

struct mtd_erase_region_info {
    uint64_t offset;        /* At which this region starts, from the beginning of the MTD */
    uint32_t erasesize;     /* For this region */
    uint32_t numblocks;     /* Number of blocks of erasesize in this region */
    unsigned long *lockmap;     /* If keeping bitmap of locks */
};

struct mtd_oob_ops {
    unsigned int    mode;
    size_t      len;
    size_t      retlen;
    size_t      ooblen;
    size_t      oobretlen;
    uint32_t    ooboffs;
    uint8_t     *datbuf;
    uint8_t     *oobbuf;
};

#define MTD_MAX_OOBFREE_ENTRIES_LARGE   32
#define MTD_MAX_ECCPOS_ENTRIES_LARGE    448
/*
 * Internal ECC layout control structure. For historical reasons, there is a
 * similar, smaller struct nand_ecclayout_user (in mtd-abi.h) that is retained
 * for export to user-space via the ECCGETLAYOUT ioctl.
 * nand_ecclayout should be expandable in the future simply by the above macros.
 */
struct nand_ecclayout {
    __u32 eccbytes;
    __u32 eccpos[MTD_MAX_ECCPOS_ENTRIES_LARGE];
    __u32 oobavail;
    struct nand_oobfree oobfree[MTD_MAX_OOBFREE_ENTRIES_LARGE];
};

struct module;  /* only needed for owner field in mtd_info */

struct mtd_info {
    u_char type;
    uint32_t flags;
    uint64_t size;   // Total size of the MTD

    /* "Major" erase size for the device. Naïve users may take this
     * to be the only erase size available, or may use the more detailed
     * information below if they desire
     */
    uint32_t erasesize;
    /* Minimal writable flash unit size. In case of NOR flash it is 1 (even
     * though individual bits can be cleared), in case of NAND flash it is
     * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR
     * it is of ECC block size, etc. It is illegal to have writesize = 0.
     * Any driver registering a struct mtd_info must ensure a writesize of
     * 1 or larger.
     */
    uint32_t writesize;

    /*
     * Size of the write buffer used by the MTD. MTD devices having a write
     * buffer can write multiple writesize chunks at a time. E.g. while
     * writing 4 * writesize bytes to a device with 2 * writesize bytes
     * buffer the MTD driver can (but doesn't have to) do 2 writesize
     * operations, but not 4. Currently, all NANDs have writebufsize
     * equivalent to writesize (NAND page size). Some NOR flashes do have
     * writebufsize greater than writesize.
     */
    uint32_t writebufsize;

    uint32_t oobsize;   // Amount of OOB data per block (e.g. 16)
    uint32_t oobavail;  // Available OOB bytes per block

    /*
     * If erasesize is a power of 2 then the shift is stored in
     * erasesize_shift otherwise erasesize_shift is zero. Ditto writesize.
     */
    unsigned int erasesize_shift;
    unsigned int writesize_shift;
    /* Masks based on erasesize_shift and writesize_shift */
    unsigned int erasesize_mask;
    unsigned int writesize_mask;

    /*
     * read ops return -EUCLEAN if max number of bitflips corrected on any
     * one region comprising an ecc step equals or exceeds this value.
     * Settable by driver, else defaults to ecc_strength.  User can override
     * in sysfs.  N.B. The meaning of the -EUCLEAN return code has changed;
     * see Documentation/ABI/testing/sysfs-class-mtd for more detail.
     */
    unsigned int bitflip_threshold;

    // Kernel-only stuff starts here.
    const char *name;
    int index;

    /* ECC layout structure pointer - read only! */
    struct nand_ecclayout *ecclayout;

    /* max number of correctible bit errors per ecc step */
    unsigned int ecc_strength;

    /* Data for variable erase regions. If numeraseregions is zero,
     * it means that the whole device has erasesize as given above.
     */
    int numeraseregions;
    struct mtd_erase_region_info *eraseregions;

    /*
     * Do not call via these pointers, use corresponding mtd_*()
     * wrappers instead.
     */
    int (*_erase) (struct mtd_info *mtd, struct erase_info *instr);
    int (*_point) (struct mtd_info *mtd, loff_t from, size_t len,
               size_t *retlen, void **virt, resource_size_t *phys);
    int (*_unpoint) (struct mtd_info *mtd, loff_t from, size_t len);
    unsigned long (*_get_unmapped_area) (struct mtd_info *mtd,
                         unsigned long len,
                         unsigned long offset,
                         unsigned long flags);
    int (*_read) (struct mtd_info *mtd, loff_t from, size_t len,
              size_t *retlen, u_char *buf);
    int (*_write) (struct mtd_info *mtd, loff_t to, size_t len,
               size_t *retlen, const u_char *buf);
    int (*_panic_write) (struct mtd_info *mtd, loff_t to, size_t len,
                 size_t *retlen, const u_char *buf);
    int (*_read_oob) (struct mtd_info *mtd, loff_t from,
              struct mtd_oob_ops *ops);
    int (*_write_oob) (struct mtd_info *mtd, loff_t to,
               struct mtd_oob_ops *ops);
    int (*_get_fact_prot_info) (struct mtd_info *mtd, struct otp_info *buf,
                    size_t len);
    int (*_read_fact_prot_reg) (struct mtd_info *mtd, loff_t from,
                    size_t len, size_t *retlen, u_char *buf);
    int (*_get_user_prot_info) (struct mtd_info *mtd, struct otp_info *buf,
                    size_t len);
    int (*_read_user_prot_reg) (struct mtd_info *mtd, loff_t from,
                    size_t len, size_t *retlen, u_char *buf);
    int (*_write_user_prot_reg) (struct mtd_info *mtd, loff_t to,
                     size_t len, size_t *retlen, u_char *buf);
    int (*_lock_user_prot_reg) (struct mtd_info *mtd, loff_t from,
                    size_t len);
    int (*_writev) (struct mtd_info *mtd, const struct kvec *vecs,
            unsigned long count, loff_t to, size_t *retlen);
    void (*_sync) (struct mtd_info *mtd);
    int (*_lock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
    int (*_unlock) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
    int (*_is_locked) (struct mtd_info *mtd, loff_t ofs, uint64_t len);
    int (*_block_isbad) (struct mtd_info *mtd, loff_t ofs);
    int (*_block_markbad) (struct mtd_info *mtd, loff_t ofs);
    int (*_suspend) (struct mtd_info *mtd);
    void (*_resume) (struct mtd_info *mtd);
    /*
     * If the driver is something smart, like UBI, it may need to maintain
     * its own reference counting. The below functions are only for driver.
     */
    int (*_get_device) (struct mtd_info *mtd);
    void (*_put_device) (struct mtd_info *mtd);

    /* Backing device capabilities for this device
     * - provides mmap capabilities
     */
    struct backing_dev_info *backing_dev_info;

    struct notifier_block reboot_notifier;  /* default mode before reboot */

    /* ECC status information */
    struct mtd_ecc_stats ecc_stats;
    /* Subpage shift (NAND) */
    int subpage_sft;

    void *priv;

    struct module *owner;
    struct device dev;
    int usecount;
};

int mtd_erase(struct mtd_info *mtd, struct erase_info *instr);
int mtd_point(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
          void **virt, resource_size_t *phys);
int mtd_unpoint(struct mtd_info *mtd, loff_t from, size_t len);
unsigned long mtd_get_unmapped_area(struct mtd_info *mtd, unsigned long len,
                    unsigned long offset, unsigned long flags);
int mtd_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen,
         u_char *buf);
int mtd_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
          const u_char *buf);
int mtd_panic_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen,
            const u_char *buf);

int mtd_read_oob(struct mtd_info *mtd, loff_t from, struct mtd_oob_ops *ops);

static inline int mtd_write_oob(struct mtd_info *mtd, loff_t to,
                struct mtd_oob_ops *ops)
{
    ops->retlen = ops->oobretlen = 0;
    if (!mtd->_write_oob)
        return -EOPNOTSUPP;
    if (!(mtd->flags & MTD_WRITEABLE))
        return -EROFS;
    return mtd->_write_oob(mtd, to, ops);
}

int mtd_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
               size_t len);
int mtd_read_fact_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
               size_t *retlen, u_char *buf);
int mtd_get_user_prot_info(struct mtd_info *mtd, struct otp_info *buf,
               size_t len);
int mtd_read_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len,
               size_t *retlen, u_char *buf);
int mtd_write_user_prot_reg(struct mtd_info *mtd, loff_t to, size_t len,
                size_t *retlen, u_char *buf);
int mtd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from, size_t len);

int mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
           unsigned long count, loff_t to, size_t *retlen);

static inline void mtd_sync(struct mtd_info *mtd)
{
    if (mtd->_sync)
        mtd->_sync(mtd);
}

int mtd_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len);
int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs);
int mtd_block_markbad(struct mtd_info *mtd, loff_t ofs);

static inline int mtd_suspend(struct mtd_info *mtd)
{
    return mtd->_suspend ? mtd->_suspend(mtd) : 0;
}

static inline void mtd_resume(struct mtd_info *mtd)
{
    if (mtd->_resume)
        mtd->_resume(mtd);
}

static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd)
{
    if (mtd->erasesize_shift)
        return sz >> mtd->erasesize_shift;
    do_div(sz, mtd->erasesize);
    return sz;
}

static inline uint32_t mtd_mod_by_eb(uint64_t sz, struct mtd_info *mtd)
{
    if (mtd->erasesize_shift)
        return sz & mtd->erasesize_mask;
    return do_div(sz, mtd->erasesize);
}

static inline uint32_t mtd_div_by_ws(uint64_t sz, struct mtd_info *mtd)
{
    if (mtd->writesize_shift)
        return sz >> mtd->writesize_shift;
    do_div(sz, mtd->writesize);
    return sz;
}

static inline uint32_t mtd_mod_by_ws(uint64_t sz, struct mtd_info *mtd)
{
    if (mtd->writesize_shift)
        return sz & mtd->writesize_mask;
    return do_div(sz, mtd->writesize);
}

static inline int mtd_has_oob(const struct mtd_info *mtd)
{
    return mtd->_read_oob && mtd->_write_oob;
}

static inline int mtd_can_have_bb(const struct mtd_info *mtd)
{
    return !!mtd->_block_isbad;
}

    /* Kernel-side ioctl definitions */

struct mtd_partition;
struct mtd_part_parser_data;

extern int mtd_device_parse_register(struct mtd_info *mtd,
                  const char **part_probe_types,
                  struct mtd_part_parser_data *parser_data,
                  const struct mtd_partition *defparts,
                  int defnr_parts);
#define mtd_device_register(master, parts, nr_parts)    \
    mtd_device_parse_register(master, NULL, NULL, parts, nr_parts)
extern int mtd_device_unregister(struct mtd_info *master);
extern struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num);
extern int __get_mtd_device(struct mtd_info *mtd);
extern void __put_mtd_device(struct mtd_info *mtd);
extern struct mtd_info *get_mtd_device_nm(const char *name);
extern void put_mtd_device(struct mtd_info *mtd);


struct mtd_notifier {
    void (*add)(struct mtd_info *mtd);
    void (*remove)(struct mtd_info *mtd);
    struct list_head list;
};


extern void register_mtd_user (struct mtd_notifier *new);
extern int unregister_mtd_user (struct mtd_notifier *old);
void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);

void mtd_erase_callback(struct erase_info *instr);

static inline int mtd_is_bitflip(int err) {
    return err == -EUCLEAN;
}

static inline int mtd_is_eccerr(int err) {
    return err == -EBADMSG;
}

static inline int mtd_is_bitflip_or_eccerr(int err) {
    return mtd_is_bitflip(err) || mtd_is_eccerr(err);
}

#endif /* __MTD_MTD_H__ */