1/*
2 * arch/um/drivers/mmapper_kern.c
3 *
4 * BRIEF MODULE DESCRIPTION
5 *
6 * Copyright (C) 2000 RidgeRun, Inc.
7 * Author: RidgeRun, Inc.
8 *         Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com
9 *
10 */
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/mm.h>
15#include <linux/miscdevice.h>
16#include <asm/uaccess.h>
17#include "mem_user.h"
18
19/* These are set in mmapper_init, which is called at boot time */
20static unsigned long mmapper_size;
21static unsigned long p_buf = 0;
22static char *v_buf = NULL;
23
24static ssize_t
25mmapper_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
26{
27	return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size);
28}
29
30static ssize_t
31mmapper_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
32{
33	if (*ppos > mmapper_size)
34		return -EINVAL;
35
36	if (count > mmapper_size - *ppos)
37		count = mmapper_size - *ppos;
38
39	if (copy_from_user(&v_buf[*ppos], buf, count))
40		return -EFAULT;
41
42	return count;
43}
44
45static int
46mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
47	 unsigned long arg)
48{
49	return(-ENOIOCTLCMD);
50}
51
52static int
53mmapper_mmap(struct file *file, struct vm_area_struct * vma)
54{
55	int ret = -EINVAL;
56	int size;
57
58	if (vma->vm_pgoff != 0)
59		goto out;
60
61	size = vma->vm_end - vma->vm_start;
62	if(size > mmapper_size) return(-EFAULT);
63
64	if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size,
65			     vma->vm_page_prot))
66		goto out;
67	ret = 0;
68out:
69	return ret;
70}
71
72static int
73mmapper_open(struct inode *inode, struct file *file)
74{
75	return 0;
76}
77
78static int
79mmapper_release(struct inode *inode, struct file *file)
80{
81	return 0;
82}
83
84static const struct file_operations mmapper_fops = {
85	.owner		= THIS_MODULE,
86	.read		= mmapper_read,
87	.write		= mmapper_write,
88	.ioctl		= mmapper_ioctl,
89	.mmap		= mmapper_mmap,
90	.open		= mmapper_open,
91	.release	= mmapper_release,
92};
93
94/* No locking needed - only used (and modified) by below initcall and exitcall. */
95static struct miscdevice mmapper_dev = {
96	.minor		= MISC_DYNAMIC_MINOR,
97	.name		= "mmapper",
98	.fops		= &mmapper_fops
99};
100
101static int __init mmapper_init(void)
102{
103	int err;
104
105	printk(KERN_INFO "Mapper v0.1\n");
106
107	v_buf = (char *) find_iomem("mmapper", &mmapper_size);
108	if(mmapper_size == 0){
109		printk(KERN_ERR "mmapper_init - find_iomem failed\n");
110		goto out;
111	}
112
113	err = misc_register(&mmapper_dev);
114	if(err){
115		printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
116		       err);
117		goto out;
118	}
119
120	p_buf = __pa(v_buf);
121out:
122	return 0;
123}
124
125static void mmapper_exit(void)
126{
127	misc_deregister(&mmapper_dev);
128}
129
130module_init(mmapper_init);
131module_exit(mmapper_exit);
132
133MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>");
134MODULE_DESCRIPTION("DSPLinux simulator mmapper driver");
135/*
136 * ---------------------------------------------------------------------------
137 * Local variables:
138 * c-file-style: "linux"
139 * End:
140 */
141