Merge with /home/shaggy/git/linus-clean/
[linux-2.6] / arch / um / drivers / mmapper_kern.c
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 <linux/miscdevice.h>
22 #include <asm/uaccess.h>
23 #include <asm/irq.h>
24 #include <asm/pgtable.h>
25 #include "mem_user.h"
26 #include "user_util.h"
27  
28 /* These are set in mmapper_init, which is called at boot time */
29 static unsigned long mmapper_size;
30 static unsigned long p_buf = 0;
31 static char *v_buf = NULL;
32
33 static ssize_t
34 mmapper_read(struct file *file, char *buf, size_t count, loff_t *ppos)
35 {
36         if(*ppos > mmapper_size)
37                 return -EINVAL;
38
39         if(count + *ppos > mmapper_size)
40                 count = count + *ppos - mmapper_size;
41
42         if(count < 0)
43                 return -EINVAL;
44  
45         copy_to_user(buf,&v_buf[*ppos],count);
46         
47         return count;
48 }
49
50 static ssize_t
51 mmapper_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
52 {
53         if(*ppos > mmapper_size)
54                 return -EINVAL;
55
56         if(count + *ppos > mmapper_size)
57                 count = count + *ppos - mmapper_size;
58
59         if(count < 0)
60                 return -EINVAL;
61
62         copy_from_user(&v_buf[*ppos],buf,count);
63         
64         return count;
65 }
66
67 static int 
68 mmapper_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
69          unsigned long arg)
70 {
71         return(-ENOIOCTLCMD);
72 }
73
74 static int 
75 mmapper_mmap(struct file *file, struct vm_area_struct * vma)
76 {
77         int ret = -EINVAL;
78         int size;
79
80         lock_kernel();
81         if (vma->vm_pgoff != 0)
82                 goto out;
83         
84         size = vma->vm_end - vma->vm_start;
85         if(size > mmapper_size) return(-EFAULT);
86
87         /* XXX A comment above remap_pfn_range says it should only be
88          * called when the mm semaphore is held
89          */
90         if (remap_pfn_range(vma, vma->vm_start, p_buf >> PAGE_SHIFT, size,
91                              vma->vm_page_prot))
92                 goto out;
93         ret = 0;
94 out:
95         unlock_kernel();
96         return ret;
97 }
98
99 static int
100 mmapper_open(struct inode *inode, struct file *file)
101 {
102         return 0;
103 }
104
105 static int 
106 mmapper_release(struct inode *inode, struct file *file)
107 {
108         return 0;
109 }
110
111 static struct file_operations mmapper_fops = {
112         .owner          = THIS_MODULE,
113         .read           = mmapper_read,
114         .write          = mmapper_write,
115         .ioctl          = mmapper_ioctl,
116         .mmap           = mmapper_mmap,
117         .open           = mmapper_open,
118         .release        = mmapper_release,
119 };
120
121 static struct miscdevice mmapper_dev = {
122         .minor          = MISC_DYNAMIC_MINOR,
123         .name           = "mmapper",
124         .fops           = &mmapper_fops
125 };
126
127 static int __init mmapper_init(void)
128 {
129         int err;
130
131         printk(KERN_INFO "Mapper v0.1\n");
132
133         v_buf = (char *) find_iomem("mmapper", &mmapper_size);
134         if(mmapper_size == 0){
135                 printk(KERN_ERR "mmapper_init - find_iomem failed\n");
136                 goto out;
137         }
138
139         err = misc_register(&mmapper_dev);
140         if(err){
141                 printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
142                        err);
143                 goto out;
144         }
145
146         p_buf = __pa(v_buf);
147 out:
148         return 0;
149 }
150
151 static void mmapper_exit(void)
152 {
153         misc_deregister(&mmapper_dev);
154 }
155
156 module_init(mmapper_init);
157 module_exit(mmapper_exit);
158
159 MODULE_AUTHOR("Greg Lonnon <glonnon@ridgerun.com>");
160 MODULE_DESCRIPTION("DSPLinux simulator mmapper driver");
161 /*
162  * ---------------------------------------------------------------------------
163  * Local variables:
164  * c-file-style: "linux"
165  * End:
166  */