#define writeb(b,addr) (*(volatile unsigned char *) __io_virt(addr) = (b))
#define writew(b,addr) (*(volatile unsigned short *) __io_virt(addr) = (b))
#define writel(b,addr) (*(volatile unsigned int *) __io_virt(addr) = (b))

#define memset_io(a,b,c) memset(__io_virt(a),(b),(c))
#define memcpy_fromio(a,b,c) memcpy((a),__io_virt(b),(c))
#define memcpy_toio(a,b,c) memcpy(__io_virt(a),(b),(c))

if (rtc_tm->tm_sec == 0) {
/* Re-read all BCD registers in case of BCDSEC is 0.
See RTC section at the manual for more info. */
goto read_rtc_bcd_time;
}
}
spin_unlock_irq(&rtc_lock);

BCD_TO_BIN(rtc_tm->tm_year);
BCD_TO_BIN(rtc_tm->tm_mon);
BCD_TO_BIN(rtc_tm->tm_mday);
BCD_TO_BIN(rtc_tm->tm_hour);
BCD_TO_BIN(rtc_tm->tm_min);
BCD_TO_BIN(rtc_tm->tm_sec);

/* The epoch of tm_year is 1900 */
rtc_tm->tm_year += RTC_LEAP_YEAR - 1900;

/* tm_mon starts at 0, but rtc month starts at 1 */
rtc_tm->tm_mon--;
}

MODULE_PARM(mem_start, "i");
MODULE_PARM(mem_size, "i");

static int mem_start = 101, mem_size = 10;
static char *reserve_virt_addr;
static int major;

int mmapdrv_open(struct inode *inode, struct file *file);
int mmapdrv_release(struct inode *inode, struct file *file);
int mmapdrv_mmap(struct file *file, struct vm_area_struct *vma);

static struct file_operations mmapdrv_fops =
{
owner: THIS_MODULE, mmap: mmapdrv_mmap, open: mmapdrv_open, release:
mmapdrv_release,
};

int init_module(void)
{
if ((major = register_chrdev(0, "mmapdrv", &mmapdrv_fops)) < 0)
{
printk("mmapdrv: unable to register character device/n");
return ( - EIO);
}
printk("mmap device major = %d/n", major);

printk("high memory physical address 0x%ldM/n", virt_to_phys(high_memory) /
1024 / 1024);

reserve_virt_addr = ioremap(mem_start *1024 * 1024, mem_size *1024 * 1024);
printk("reserve_virt_addr = 0x%lx/n", (unsigned long)reserve_virt_addr);
if (reserve_virt_addr)
{
int i;
for (i = 0; i < mem_size *1024 * 1024; i += 4)
{
reserve_virt_addr[i] = 'a';
reserve_virt_addr[i + 1] = 'b';
reserve_virt_addr[i + 2] = 'c';
reserve_virt_addr[i + 3] = 'd';
}
}
else
{
unregister_chrdev(major, "mmapdrv");
return - ENODEV;
}
return 0;
}

/* remove the module */
void cleanup_module(void)
{
if (reserve_virt_addr)
iounmap(reserve_virt_addr);

unregister_chrdev(major, "mmapdrv");
return ;
}

int mmapdrv_open(struct inode *inode, struct file *file)
{
MOD_INC_USE_COUNT;
return (0);
}

int mmapdrv_release(struct inode *inode, struct file *file)
{
MOD_DEC_USE_COUNT;
return (0);
}

int mmapdrv_mmap(struct file *file, struct vm_area_struct *vma)
{
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
unsigned long size = vma->vm_end - vma->vm_start;

if (size > mem_size *1024 * 1024)
{
printk("size too big/n");
return ( - ENXIO);
}

offset = offset + mem_start * 1024 * 1024;

/* we do not want to have this area swapped out, lock it */
vma->vm_flags |= VM_LOCKED;
if (remap_page_range(vma, vma->vm_start, offset, size, PAGE_SHARED))
{
printk("remap page range failed/n");
return - ENXIO;
}
return (0);
}