1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* 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:
*/
|
