zlg_fs.c

本程序是对ARM9的嵌入式系统开发的驱动程序的代码

{
    int num;
    Disk_RW_Parameter dp;
    unsigned long flag;
    int part1, npart, i;

    num = DEVICE_NR(inode->i_rdev);
    if (num >= MAX_DISKS)
    {
        return -ENODEV;
    }

    if (DiskInfo[num] == NULL)
    {
        return -ENODEV;
    }

    //local_irq_save(flag);
    ZLG_FS_usage[num]--;
    if (ZLG_FS_usage[num] == 0)
    {
        if (DiskInfo[num]->release != NULL)
        {
            DiskInfo[num]->release(inode, filp);
        }

        part1 = (num << ZLG_FS_SHIFT);
        npart = (1 << ZLG_FS_SHIFT) -1;

        dp.RsvdForLow = DiskInfo[num]->RsvdForLow;
        DiskInfo[num]->DiakCommand(DISK_CLOSE, &dp);
        
        for (i = 0; i <= npart; i++)
        {
            fsync_dev(MKDEV(major, part1++));
        }        
    }
    //local_irq_restore(flag);

    MOD_DEC_USE_COUNT;
    return 0; 
} 

/*********************************************************************************************************
** Function name: zlg_fs_ioctl
** Descriptions: IO control function
** Input:inode:  information of device
**       filp:   pointer of file
**       cmd:    command
**       arg:    additive parameter
** Output 0:     OK
**        other: not OK
** Created by:   Chenmingji
** Created Date: 2005-05-25
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static int zlg_fs_ioctl(struct inode *inode, struct file *filp, 
                    unsigned int cmd, unsigned long arg)
{
    long err, size;
    struct hd_geometry geo;
    int num;

    num = DEVICE_NR(inode->i_rdev);
    if (num >= MAX_DISKS)
    {
        return -ENODEV;
    }

    if (DiskInfo[num] == NULL)
    {
        return -ENODEV;
    }

    switch(cmd) 
    {
        case BLKGETSIZE:
            /* Return the device size, expressed in sectors */
            if (arg == 0)
            {
                return -EINVAL; /* NULL pointer: not valid */
            }
            if(access_ok(VERIFY_WRITE, arg, sizeof(long)) == 0)
            {
                return -EFAULT;
            }
            size = zlg_fs_gendisk.part[MINOR(inode->i_rdev)].nr_sects;
	        if (copy_to_user((long *) arg, &size, sizeof (long)))
	        {
	            return -EFAULT;
	        }
            return 0;

//        case BLKFLSBUF: /* flush */
//            if (! capable(CAP_SYS_RAWIO)) return -EACCES; /* only root */
//            fsync_dev(inode->i_rdev);
//            invalidate_buffers(inode->i_rdev);
//            return 0;

//        case BLKRAGET: /* return the readahead value */
//            err = ! access_ok(VERIFY_WRITE, arg, sizeof(long));
//            if (err) return -EFAULT;
//            PUT_USER(read_ahead[MAJOR(inode->i_rdev)],(long *) arg);
//            return 0;

//        case BLKRASET: /* set the readahead value */
//            if (!capable(CAP_SYS_RAWIO)) return -EACCES;
//            if (arg > 0xff) return -EINVAL; /* limit it */
//            read_ahead[MAJOR(inode->i_rdev)] = arg;
//            return 0;
        
        case BLKRRPART: /* re-read partition table: can't do it */
            return zlg_fs_revalidate(inode->i_rdev);

        case HDIO_GETGEO:
           /*
	        * Get geometry: since we are a virtual device, we have to make
	        * up something plausible.  So we claim 16 sectors, four heads,
	        * and calculate the corresponding number of cylinders.  We set the
	        * start of data at sector four.
            */
            if (access_ok(VERIFY_WRITE, arg, sizeof(geo)) == 0)
            {
                return -EFAULT;
            }

            size = DiskInfo[num]->SecPerDisk;
            geo.cylinders = (size & ~0x3f) >> 6;
	        geo.heads = 4;
	        geo.sectors = 16;
	        geo.start = 0;
	        if (copy_to_user((void *) arg, &geo, sizeof(geo)))
	        {
	            return -EFAULT;
	        }
            return 0;

        default:
        /*
         * For ioctls we don't understand, let the block layer handle them.
         */
            return blk_ioctl(inode->i_rdev, cmd, arg);
    }
    return -ENOTTY; /* unknown command */
}

/*********************************************************************************************************
** Function name: check_zlg_fs_change
** Descriptions: 
** Input:dev:
** Output 0:     OK
**        other: not OK
** Created by:   Chenmingji
** Created Date: 2005-05-25
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static int check_zlg_fs_change(kdev_t dev)
{
    int num;
    Disk_RW_Parameter dp;

    num = DEVICE_NR(dev);
    if (num >= MAX_DISKS)
    {
        return -ENODEV;
    }

    if (DiskInfo[num] == NULL)
    {
        return -ENODEV;
    }

    dp.RsvdForLow = DiskInfo[num]->RsvdForLow;

    if (DiskInfo[num]->DiakCommand(DISK_CHECK_CHANGE, &dp) == DISK_TRUE)
    {
        return 1;
    }

    return 0;
}

/*********************************************************************************************************
** Function name: zlg_fs_revalidate
** Descriptions: revalidate device
** Input:dev:    nformation of device
** Output 0:     OK
**        1:     not OK
** Created by:   Chenmingji
** Created Date: 2005-05-25
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        static int zlg_fs_revalidate(kdev_t dev)
{
    int num;
    unsigned long flag;
    int part1, npart, i;

    num = DEVICE_NR(dev);
    if (num >= MAX_DISKS)
    {
        return -ENODEV;
    }

    if (DiskInfo[num] == NULL)
    {
        return -ENODEV;
    }

    if (DiskInfo[num]->get_info == NULL)
    {
        return -ENODEV;
    }
    DiskInfo[num]->get_info(DiskInfo[num]);

    part1 = (num << ZLG_FS_SHIFT) + 1;
    npart = (1 << ZLG_FS_SHIFT) - 1;

    memset(zlg_fs_gendisk.sizes + part1, 0, npart * sizeof(int));
    memset(zlg_fs_gendisk.part + part1, 0, npart * sizeof(struct hd_struct));

    //local_irq_save(flag);
 
    for (i = 0; i <= npart; i++)
    {
        part1++;
        ZLG_FS_blocksizes[part1] = DiskInfo[num]->BytesPerSec;
        ZLG_FS_sizes[part1] = (DiskInfo[num]->SecPerDisk * ZLG_FS_blocksizes[num])
                              / 1024;       
    }

    zlg_fs_gendisk.part[num << ZLG_FS_SHIFT].nr_sects = DiskInfo[num]->SecPerDisk;
    
    register_disk(&zlg_fs_gendisk, dev, 1 << ZLG_FS_SHIFT,
                  &zlg_fs_fops, DiskInfo[num]->SecPerDisk);
    //local_irq_restore(flag);

    return 0;
}

/*********************************************************************************************************
** Function name: zlg_fs_init
** Descriptions: init driver
** Input:none
** Output 0:     OK
**        other: not OK
** Created by:   Chenmingji
** Created Date: 2005-05-25
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        int  zlg_fs_init(void)
{
    int  result, i;

    result = register_blkdev(MAJOR_NR,  DEVICE_NAME,  &zlg_fs_fops); 
    if (result < 0)
    {
        printk(KERN_ERR DEVICE_NAME ": Unable to get major %d\n", MAJOR_NR );
        return(result); 
    } 
    if (MAJOR_NR == 0)
    {
        MAJOR_NR = result; /* dynamic */
    }

    zlg_fs_gendisk.major = major;
    zlg_fs_gendisk.major_name = DEVICE_NAME;
    zlg_fs_gendisk.minor_shift = ZLG_FS_SHIFT;
    zlg_fs_gendisk.max_p = 1 << ZLG_FS_SHIFT;
    zlg_fs_gendisk.fops = &zlg_fs_fops;
    zlg_fs_gendisk.sizes = ZLG_FS_sizes;
    zlg_fs_gendisk.nr_real = MAX_DISKS;
    zlg_fs_gendisk.part = part;

    zlg_fs_gendisk.next = gendisk_head;
    gendisk_head = &zlg_fs_gendisk; 

    //blk_init_queue(BLK_DEFAULT_QUEUE(MAJOR_NR), zlg_fs_queue);
    blk_queue_make_request(BLK_DEFAULT_QUEUE(MAJOR_NR), zlg_fs_make_request);
    blk_size[MAJOR_NR] = ZLG_FS_sizes;
    blksize_size[MAJOR_NR] = ZLG_FS_blocksizes;

    printk(KERN_INFO DEVICE_NAME ": init OK\n");
    return 0; 
}

/*********************************************************************************************************
** Function name: zlg_fs_cleanup
** Descriptions: exit driver
** Input:none
** Output none
** Created by:   Chenmingji
** Created Date: 2005-05-25
**-------------------------------------------------------------------------------------------------------
** Modified by:
** Modified Date: 
**------------------------------------------------------------------------------------------------------
********************************************************************************************************/
        void zlg_fs_cleanup(void)
{
    unregister_blkdev(MAJOR_NR, DEVICE_NAME);
}

/*********************************************************************************************************
**                            End Of File
********************************************************************************************************/