/*
* arch/um/drivers/mmapper_kern.c
*
* BRIEF MODULE DESCRIPTION
*
* Copyright (C) 2000 RidgeRun, Inc.
* Author: RidgeRun, Inc.
* Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com
*
*/
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/time.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <asm/pgtable.h>
#include "mem_user.h"
#include "user_util.h"
/* These are set in mmapper_init, which is called at boot time */
static unsigned long mmapper_size;
static unsigned long p_buf = 0;
static char *v_buf = NULL;
static ssize_t
mmapper_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
if(*ppos > mmapper_size)
return -EINVAL;
if(count + *ppos > mmapper_size)
count = count + *ppos - mmapper_size;
if(count < 0)
return -EINVAL;
copy_to_user(buf,&v_buf[*ppos],count);
return count;
}
static ssize_t
mmapper_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
if(*ppos > mmapper_size)
return -EINVAL;
if(count + *ppos > mmapper_size)
count = count + *ppos - mmapper_size;
if(count < 0)
return -EINVAL;
copy_from_user(&v_buf[*ppos],buf,count);
return count;
}
static int
mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
return(-ENOIOCTLCMD);
}
static int
mmapper_mmap(struct file *file, struct vm_area_struct * vma)
{
int ret = -EINVAL;
int size;
lock_kernel();
if (vma->vm_pgoff != 0)
goto out;
size = vma->vm_end - vma->vm_start;
if(size > mmapper_size) return(-EFAULT);
/* XXX A comment above remap_pfn_range says it should only be
* called when the mm semaphore is held
*/
if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size,
vma->vm_page_prot))
goto out;
ret = 0;
out:
unlock_kernel();
return ret;
}
static int
mmapper_open(struct inode *inode, struct file *file)
{
return 0;
}
static int
mmapper_release(struct inode *inode, struct file *file)
{
return 0;
}
static struct file_operations mmapper_fops = {
.owner = THIS_MODULE,
.read = mmapper_read,
.write = mmapper_write,
.ioctl = mmapper_ioctl,
.mmap = mmapper_mmap,
.open = mmapper_open,
.release = mmapper_release,
};
static int __init mmapper_init(void)
{
printk(KERN_INFO "Mapper v0.1\n");
v_buf = (char *) find_iomem("mmapper", &mmapper_size);
if(mmapper_size == 0){
printk(KERN_ERR "mmapper_init - find_iomem failed\n");
return(0);
}
p_buf = __pa(v_buf);
devfs_mk_cdev(MKDEV(30, 0), S_IFCHR|S_IRUGO|S_IWUGO, "mmapper");
return(0);
}
static void mmapper_exit(void)
{
}
module_init(mmapper_init);
module_exit(mmapper_exit);
MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>");
MODULE_DESCRIPTION("DSPLinux simulator mmapper driver");
/*
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/
