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review.evervolv.com / android_kernel_lge_hammerhead / 7c00c31fc0f003363773121a0ac6f4e5b128e879 / . / arch / um / drivers / mmapper_kern.c
blob: a63231dffe058efc6ace1a2364715fd39f081df4 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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/types.h>
13#include <linux/kdev_t.h>
14#include <linux/time.h>
15#include <linux/devfs_fs_kernel.h>
16#include <linux/module.h>
17#include <linux/mm.h>
18#include <linux/slab.h>
19#include <linux/init.h>
20#include <linux/smp_lock.h>
21#include <asm/uaccess.h>
22#include <asm/irq.h>
23#include <asm/pgtable.h>
24#include "mem_user.h"
25#include "user_util.h"
26
27/* These are set in mmapper_init, which is called at boot time */
28static unsigned long mmapper_size;
29static unsigned long p_buf = 0;
30static char *v_buf = NULL;
31
32static ssize_t
33mmapper_read(struct file *file, char *buf, size_t count, loff_t *ppos)
34{
35 if(*ppos > mmapper_size)
36 return -EINVAL;
37
38 if(count + *ppos > mmapper_size)
39 count = count + *ppos - mmapper_size;
40
41 if(count < 0)
42 return -EINVAL;
43
44 copy_to_user(buf,&v_buf[*ppos],count);
45
46 return count;
47}
48
49static ssize_t
50mmapper_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
51{
52 if(*ppos > mmapper_size)
53 return -EINVAL;
54
55 if(count + *ppos > mmapper_size)
56 count = count + *ppos - mmapper_size;
57
58 if(count < 0)
59 return -EINVAL;
60
61 copy_from_user(&v_buf[*ppos],buf,count);
62
63 return count;
64}
65
66static int
67mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
68 unsigned long arg)
69{
70 return(-ENOIOCTLCMD);
71}
72
73static int
74mmapper_mmap(struct file *file, struct vm_area_struct * vma)
75{
76 int ret = -EINVAL;
77 int size;
78
79 lock_kernel();
80 if (vma->vm_pgoff != 0)
81 goto out;
82
83 size = vma->vm_end - vma->vm_start;
84 if(size > mmapper_size) return(-EFAULT);
85
86 /* XXX A comment above remap_pfn_range says it should only be
87 * called when the mm semaphore is held
88 */
89 if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size,
90 vma->vm_page_prot))
91 goto out;
92 ret = 0;
93out:
94 unlock_kernel();
95 return ret;
96}
97
98static int
99mmapper_open(struct inode *inode, struct file *file)
100{
101 return 0;
102}
103
104static int
105mmapper_release(struct inode *inode, struct file *file)
106{
107 return 0;
108}
109
110static struct file_operations mmapper_fops = {
111 .owner = THIS_MODULE,
112 .read = mmapper_read,
113 .write = mmapper_write,
114 .ioctl = mmapper_ioctl,
115 .mmap = mmapper_mmap,
116 .open = mmapper_open,
117 .release = mmapper_release,
118};
119
120static int __init mmapper_init(void)
121{
122 printk(KERN_INFO "Mapper v0.1\n");
123
124 v_buf = (char *) find_iomem("mmapper", &mmapper_size);
125 if(mmapper_size == 0){
126 printk(KERN_ERR "mmapper_init - find_iomem failed\n");
127 return(0);
128 }
129
130 p_buf = __pa(v_buf);
131
132 devfs_mk_cdev(MKDEV(30, 0), S_IFCHR|S_IRUGO|S_IWUGO, "mmapper");
133 return(0);
134}
135
136static void mmapper_exit(void)
137{
138}
139
140module_init(mmapper_init);
141module_exit(mmapper_exit);
142
143MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>");
144MODULE_DESCRIPTION("DSPLinux simulator mmapper driver");
145/*
146 * ---------------------------------------------------------------------------
147 * Local variables:
148 * c-file-style: "linux"
149 * End:
150 */