tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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#include "user_util.h"
19
20/* These are set in mmapper_init, which is called at boot time */
21static unsigned long mmapper_size;
22static unsigned long p_buf = 0;
23static char *v_buf = NULL;
24
25static ssize_t
26mmapper_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
27{
28 return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size);
29}
30
31static ssize_t
32mmapper_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
33{
34 if (*ppos > mmapper_size)
35 return -EINVAL;
36
37 if (count > mmapper_size - *ppos)
38 count = mmapper_size - *ppos;
39
40 if (copy_from_user(&v_buf[*ppos], buf, count))
41 return -EFAULT;
42
43 return count;
44}
45
46static int
47mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
48 unsigned long arg)
49{
50 return(-ENOIOCTLCMD);
51}
52
53static int
54mmapper_mmap(struct file *file, struct vm_area_struct * vma)
55{
56 int ret = -EINVAL;
57 int size;
58
59 if (vma->vm_pgoff != 0)
60 goto out;
61
62 size = vma->vm_end - vma->vm_start;
63 if(size > mmapper_size) return(-EFAULT);
64
65 /* XXX A comment above remap_pfn_range says it should only be
66 * called when the mm semaphore is held
67 */
68 if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size,
69 vma->vm_page_prot))
70 goto out;
71 ret = 0;
72out:
73 return ret;
74}
75
76static int
77mmapper_open(struct inode *inode, struct file *file)
78{
79 return 0;
80}
81
82static int
83mmapper_release(struct inode *inode, struct file *file)
84{
85 return 0;
86}
87
88static struct file_operations mmapper_fops = {
89 .owner = THIS_MODULE,
90 .read = mmapper_read,
91 .write = mmapper_write,
92 .ioctl = mmapper_ioctl,
93 .mmap = mmapper_mmap,
94 .open = mmapper_open,
95 .release = mmapper_release,
96};
97
98static struct miscdevice mmapper_dev = {
99 .minor = MISC_DYNAMIC_MINOR,
100 .name = "mmapper",
101 .fops = &mmapper_fops
102};
103
104static int __init mmapper_init(void)
105{
106 int err;
107
108 printk(KERN_INFO "Mapper v0.1\n");
109
110 v_buf = (char *) find_iomem("mmapper", &mmapper_size);
111 if(mmapper_size == 0){
112 printk(KERN_ERR "mmapper_init - find_iomem failed\n");
113 goto out;
114 }
115
116 err = misc_register(&mmapper_dev);
117 if(err){
118 printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
119 err);
120 goto out;
121 }
122
123 p_buf = __pa(v_buf);
124out:
125 return 0;
126}
127
128static void mmapper_exit(void)
129{
130 misc_deregister(&mmapper_dev);
131}
132
133module_init(mmapper_init);
134module_exit(mmapper_exit);
135
136MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>");
137MODULE_DESCRIPTION("DSPLinux simulator mmapper driver");
138/*
139 * ---------------------------------------------------------------------------
140 * Local variables:
141 * c-file-style: "linux"
142 * End:
143 */