/*************************************************************************

    > File Name: ramblock.c

    > Author:

    > Mail:

    > Created Time: 2016年11月05日 星期六 22时17分28秒

 ************************************************************************/

#include <linux/module.h>

#include <linux/errno.h>

#include <linux/interrupt.h>

#include <linux/mm.h>

#include <linux/fs.h>

#include <linux/kernel.h>

#include <linux/timer.h>

#include <linux/genhd.h>

#include <linux/hdreg.h>

#include <linux/ioport.h>

#include <linux/init.h>

#include <linux/wait.h>

#include <linux/blkdev.h>

#include <linux/blkpg.h>

#include <linux/delay.h>

#include <linux/io.h>

#include <asm/system.h>

#include <asm/uaccess.h>

#include <asm/dma.h>

#define RAMBLOCK_SIZE  (1024*1024)

struct gendisk *ramblock_disk;

static request_queue_t *ramblock_queue;

static DEFINE_SPINLOCK(ramblock_lock);

static int major;

static unsigned char *ramblock_buff;

static int ramblock_getgeo(struct block_device *bdev, struct hd_geometry *geo)

{

    /* 容量 = heads*sectors*cylinders*512 */

    geo->heads = ;

    geo->sectors = ;

    geo->cylinders = RAMBLOCK_SIZE///;

    return ;

}

static struct block_device_operations ramblock_fops = {

        .owner= THIS_MODULE,

        .getgeo = ramblock_getgeo,

};

static void do_ramblock_request(request_queue_t * q)

{

    struct request *req;

    static int r_cnt = ;

    static int w_cnt = ;

    while ((req = elv_next_request(q)) != NULL)

    {

        /* 数据传输3要素 */

        /* 源/目的 */

        unsigned long offset = req->sector*;

        /* 目的 */

        //req->buff

        /* 长度 */

        unsigned long len = req->current_nr_sectors * ;

        if(rq_data_dir(req)==READ)

        {

            memcpy(req->buffer,ramblock_buff+offset, len);

            printk("read %d\n",r_cnt++);

        }

        else

        {

            memcpy(ramblock_buff+offset, req->buffer, len);

            printk("write %d\n",w_cnt++);

        }

        end_request(req, );/* wrap up, 0 = fail, 1 = success */

    }

}

static int ramblock_init(void)

{

    /* 分配一个gendisk结构体 */

    ramblock_disk = alloc_disk();  //次设备号个数=分区个数+1

    /* 设置 */

    /* 分配/设置队列：提供读写能力 */

    ramblock_queue = blk_init_queue(do_ramblock_request, &ramblock_lock);

    /* 设置其他属性 */

    major = register_blkdev(,"ramblock");

    ramblock_disk->major = major;

    ramblock_disk->first_minor = ;

    sprintf(ramblock_disk->disk_name, "ramblock");

    ramblock_disk->fops = &ramblock_fops;

    ramblock_disk->queue = ramblock_queue;

    set_capacity(ramblock_disk, RAMBLOCK_SIZE/);

    /* 硬件相关 */

    ramblock_buff = kzalloc(RAMBLOCK_SIZE, GFP_KERNEL);

    /* 注册 */

    add_disk(ramblock_disk);

    return ;

}

static void ramblock_exit(void)

{

    unregister_blkdev(major,"ramblock");

    del_gendisk(ramblock_disk);

    put_disk(ramblock_disk);

    blk_cleanup_queue(ramblock_queue);

    kfree(ramblock_buff);

}

module_init(ramblock_init);

module_exit(ramblock_exit);

MODULE_LICENSE("GPL");