Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * arch/um/drivers/mmapper_kern.c | |
4 | * | |
5 | * BRIEF MODULE DESCRIPTION | |
6 | * | |
7 | * Copyright (C) 2000 RidgeRun, Inc. | |
8 | * Author: RidgeRun, Inc. | |
9 | * Greg Lonnon glonnon@ridgerun.com or info@ridgerun.com | |
10 | * | |
11 | */ | |
12 | ||
cb8fa61c JD |
13 | #include <linux/stddef.h> |
14 | #include <linux/types.h> | |
4e950f6f | 15 | #include <linux/fs.h> |
cb8fa61c | 16 | #include <linux/init.h> |
3df59529 | 17 | #include <linux/miscdevice.h> |
cb8fa61c JD |
18 | #include <linux/module.h> |
19 | #include <linux/mm.h> | |
d63c489b | 20 | |
7c0f6ba6 | 21 | #include <linux/uaccess.h> |
37185b33 | 22 | #include <mem_user.h> |
cb8fa61c | 23 | |
1da177e4 LT |
24 | /* These are set in mmapper_init, which is called at boot time */ |
25 | static unsigned long mmapper_size; | |
cb8fa61c JD |
26 | static unsigned long p_buf; |
27 | static char *v_buf; | |
1da177e4 | 28 | |
cb8fa61c JD |
29 | static ssize_t mmapper_read(struct file *file, char __user *buf, size_t count, |
30 | loff_t *ppos) | |
1da177e4 | 31 | { |
6a029a90 | 32 | return simple_read_from_buffer(buf, count, ppos, v_buf, mmapper_size); |
1da177e4 LT |
33 | } |
34 | ||
cb8fa61c JD |
35 | static ssize_t mmapper_write(struct file *file, const char __user *buf, |
36 | size_t count, loff_t *ppos) | |
1da177e4 | 37 | { |
6a029a90 | 38 | if (*ppos > mmapper_size) |
1da177e4 LT |
39 | return -EINVAL; |
40 | ||
0388fae4 | 41 | return simple_write_to_buffer(v_buf, mmapper_size, ppos, buf, count); |
1da177e4 LT |
42 | } |
43 | ||
d5f1d54c | 44 | static long mmapper_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 45 | { |
cb8fa61c | 46 | return -ENOIOCTLCMD; |
1da177e4 LT |
47 | } |
48 | ||
cb8fa61c | 49 | static int mmapper_mmap(struct file *file, struct vm_area_struct *vma) |
1da177e4 LT |
50 | { |
51 | int ret = -EINVAL; | |
52 | int size; | |
53 | ||
1da177e4 LT |
54 | if (vma->vm_pgoff != 0) |
55 | goto out; | |
cb8fa61c | 56 | |
1da177e4 | 57 | size = vma->vm_end - vma->vm_start; |
cb8fa61c JD |
58 | if (size > mmapper_size) |
59 | return -EFAULT; | |
1da177e4 | 60 | |
cb8fa61c JD |
61 | /* |
62 | * XXX A comment above remap_pfn_range says it should only be | |
1da177e4 LT |
63 | * called when the mm semaphore is held |
64 | */ | |
65 | if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size, | |
cb8fa61c | 66 | vma->vm_page_prot)) |
1da177e4 LT |
67 | goto out; |
68 | ret = 0; | |
69 | out: | |
1da177e4 LT |
70 | return ret; |
71 | } | |
72 | ||
cb8fa61c | 73 | static int mmapper_open(struct inode *inode, struct file *file) |
1da177e4 LT |
74 | { |
75 | return 0; | |
76 | } | |
77 | ||
cb8fa61c | 78 | static int mmapper_release(struct inode *inode, struct file *file) |
1da177e4 LT |
79 | { |
80 | return 0; | |
81 | } | |
82 | ||
5e7672ec | 83 | static const struct file_operations mmapper_fops = { |
1da177e4 LT |
84 | .owner = THIS_MODULE, |
85 | .read = mmapper_read, | |
86 | .write = mmapper_write, | |
d5f1d54c | 87 | .unlocked_ioctl = mmapper_ioctl, |
1da177e4 LT |
88 | .mmap = mmapper_mmap, |
89 | .open = mmapper_open, | |
90 | .release = mmapper_release, | |
6038f373 | 91 | .llseek = default_llseek, |
1da177e4 LT |
92 | }; |
93 | ||
cb8fa61c JD |
94 | /* |
95 | * No locking needed - only used (and modified) by below initcall and exitcall. | |
96 | */ | |
1ba0ce6f | 97 | static struct miscdevice mmapper_dev = { |
3df59529 JD |
98 | .minor = MISC_DYNAMIC_MINOR, |
99 | .name = "mmapper", | |
100 | .fops = &mmapper_fops | |
101 | }; | |
102 | ||
1da177e4 LT |
103 | static int __init mmapper_init(void) |
104 | { | |
3df59529 JD |
105 | int err; |
106 | ||
1da177e4 LT |
107 | printk(KERN_INFO "Mapper v0.1\n"); |
108 | ||
109 | v_buf = (char *) find_iomem("mmapper", &mmapper_size); | |
cb8fa61c | 110 | if (mmapper_size == 0) { |
1da177e4 | 111 | printk(KERN_ERR "mmapper_init - find_iomem failed\n"); |
d63c489b | 112 | return -ENODEV; |
1da177e4 | 113 | } |
d63c489b | 114 | p_buf = __pa(v_buf); |
1da177e4 | 115 | |
3df59529 | 116 | err = misc_register(&mmapper_dev); |
cb8fa61c | 117 | if (err) { |
3df59529 JD |
118 | printk(KERN_ERR "mmapper - misc_register failed, err = %d\n", |
119 | err); | |
6eab04a8 | 120 | return err; |
3df59529 | 121 | } |
3df59529 | 122 | return 0; |
1da177e4 LT |
123 | } |
124 | ||
125 | static void mmapper_exit(void) | |
126 | { | |
3df59529 | 127 | misc_deregister(&mmapper_dev); |
1da177e4 LT |
128 | } |
129 | ||
130 | module_init(mmapper_init); | |
131 | module_exit(mmapper_exit); | |
132 | ||
133 | MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>"); | |
134 | MODULE_DESCRIPTION("DSPLinux simulator mmapper driver"); | |
07ecb79f | 135 | MODULE_LICENSE("GPL"); |