Commit | Line | Data |
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1da177e4 LT |
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 | ||
6a029a90 | 12 | #include <linux/init.h> |
1da177e4 LT |
13 | #include <linux/module.h> |
14 | #include <linux/mm.h> | |
3df59529 | 15 | #include <linux/miscdevice.h> |
1da177e4 | 16 | #include <asm/uaccess.h> |
1da177e4 LT |
17 | #include "mem_user.h" |
18 | #include "user_util.h" | |
19 | ||
20 | /* These are set in mmapper_init, which is called at boot time */ | |
21 | static unsigned long mmapper_size; | |
22 | static unsigned long p_buf = 0; | |
23 | static char *v_buf = NULL; | |
24 | ||
25 | static ssize_t | |
6a029a90 | 26 | mmapper_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
1da177e4 | 27 | { |
6a029a90 | 28 | return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size); |
1da177e4 LT |
29 | } |
30 | ||
31 | static ssize_t | |
6a029a90 | 32 | mmapper_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
1da177e4 | 33 | { |
6a029a90 | 34 | if (*ppos > mmapper_size) |
1da177e4 LT |
35 | return -EINVAL; |
36 | ||
6a029a90 AV |
37 | if (count > mmapper_size - *ppos) |
38 | count = mmapper_size - *ppos; | |
1da177e4 | 39 | |
6a029a90 AV |
40 | if (copy_from_user(&v_buf[*ppos], buf, count)) |
41 | return -EFAULT; | |
1da177e4 LT |
42 | |
43 | return count; | |
44 | } | |
45 | ||
46 | static int | |
47 | mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd, | |
48 | unsigned long arg) | |
49 | { | |
50 | return(-ENOIOCTLCMD); | |
51 | } | |
52 | ||
53 | static int | |
54 | mmapper_mmap(struct file *file, struct vm_area_struct * vma) | |
55 | { | |
56 | int ret = -EINVAL; | |
57 | int size; | |
58 | ||
1da177e4 LT |
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; | |
72 | out: | |
1da177e4 LT |
73 | return ret; |
74 | } | |
75 | ||
76 | static int | |
77 | mmapper_open(struct inode *inode, struct file *file) | |
78 | { | |
79 | return 0; | |
80 | } | |
81 | ||
82 | static int | |
83 | mmapper_release(struct inode *inode, struct file *file) | |
84 | { | |
85 | return 0; | |
86 | } | |
87 | ||
88 | static 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 | ||
3df59529 JD |
98 | static struct miscdevice mmapper_dev = { |
99 | .minor = MISC_DYNAMIC_MINOR, | |
100 | .name = "mmapper", | |
101 | .fops = &mmapper_fops | |
102 | }; | |
103 | ||
1da177e4 LT |
104 | static int __init mmapper_init(void) |
105 | { | |
3df59529 JD |
106 | int err; |
107 | ||
1da177e4 LT |
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"); | |
3df59529 | 113 | goto out; |
1da177e4 LT |
114 | } |
115 | ||
3df59529 JD |
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 | } | |
1da177e4 | 122 | |
3df59529 JD |
123 | p_buf = __pa(v_buf); |
124 | out: | |
125 | return 0; | |
1da177e4 LT |
126 | } |
127 | ||
128 | static void mmapper_exit(void) | |
129 | { | |
3df59529 | 130 | misc_deregister(&mmapper_dev); |
1da177e4 LT |
131 | } |
132 | ||
133 | module_init(mmapper_init); | |
134 | module_exit(mmapper_exit); | |
135 | ||
136 | MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>"); | |
137 | MODULE_DESCRIPTION("DSPLinux simulator mmapper driver"); | |
138 | /* | |
139 | * --------------------------------------------------------------------------- | |
140 | * Local variables: | |
141 | * c-file-style: "linux" | |
142 | * End: | |
143 | */ |