fwh_lock.h

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#ifndef FWH_LOCK_H
#define FWH_LOCK_H


enum fwh_lock_state {
        FWH_UNLOCKED   = 0,
    FWH_DENY_WRITE = 1,
    FWH_IMMUTABLE  = 2,
    FWH_DENY_READ  = 4,
};

struct fwh_xxlock_thunk {
    enum fwh_lock_state val;
    flstate_t state;
};


#define FWH_XXLOCK_ONEBLOCK_LOCK   ((struct fwh_xxlock_thunk){ FWH_DENY_WRITE, FL_LOCKING})
#define FWH_XXLOCK_ONEBLOCK_UNLOCK ((struct fwh_xxlock_thunk){ FWH_UNLOCKED,   FL_UNLOCKING})

/*
 * This locking/unlock is specific to firmware hub parts.  Only one
 * is known that supports the Intel command set.    Firmware
 * hub parts cannot be interleaved as they are on the LPC bus
 * so this code has not been tested with interleaved chips,
 * and will likely fail in that context.
 */
static int fwh_xxlock_oneblock(struct map_info *map, struct flchip *chip,
    unsigned long adr, int len, void *thunk)
{
    struct cfi_private *cfi = map->fldrv_priv;
    struct fwh_xxlock_thunk *xxlt = (struct fwh_xxlock_thunk *)thunk;
    int ret;

    /* Refuse the operation if the we cannot look behind the chip */
    if (chip->start < 0x400000) {
        pr_debug( "MTD %s(): chip->start: %lx wanted >= 0x400000\n",
            __func__, chip->start );
        return -EIO;
    }
    /*
     * lock block registers:
     * - on 64k boundariesand
     * - bit 1 set high
     * - block lock registers are 4MiB lower - overflow subtract (danger)
     *
     * The address manipulation is first done on the logical address
     * which is 0 at the start of the chip, and then the offset of
     * the individual chip is addted to it.  Any other order a weird
     * map offset could cause problems.
     */
    adr = (adr & ~0xffffUL) | 0x2;
    adr += chip->start - 0x400000;

    /*
     * This is easy because these are writes to registers and not writes
     * to flash memory - that means that we don't have to check status
     * and timeout.
     */
    mutex_lock(&chip->mutex);
    ret = get_chip(map, chip, adr, FL_LOCKING);
    if (ret) {
        mutex_unlock(&chip->mutex);
        return ret;
    }

    chip->oldstate = chip->state;
    chip->state = xxlt->state;
    map_write(map, CMD(xxlt->val), adr);

    /* Done and happy. */
    chip->state = chip->oldstate;
    put_chip(map, chip, adr);
    mutex_unlock(&chip->mutex);
    return 0;
}


static int fwh_lock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
    int ret;

    ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
        (void *)&FWH_XXLOCK_ONEBLOCK_LOCK);

    return ret;
}


static int fwh_unlock_varsize(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
    int ret;

    ret = cfi_varsize_frob(mtd, fwh_xxlock_oneblock, ofs, len,
        (void *)&FWH_XXLOCK_ONEBLOCK_UNLOCK);

    return ret;
}

static void fixup_use_fwh_lock(struct mtd_info *mtd)
{
    printk(KERN_NOTICE "using fwh lock/unlock method\n");
    /* Setup for the chips with the fwh lock method */
    mtd->_lock   = fwh_lock_varsize;
    mtd->_unlock = fwh_unlock_varsize;
}
#endif /* FWH_LOCK_H */