1 #include <linux/init.h>
2 #include <linux/debugfs.h>
3 #include <linux/slab.h>
4 #include <linux/module.h>
5
6 #include "debugfs.h"
7
8 static struct dentry *d_xen_debug;
9
xen_init_debugfs(void)10 struct dentry * __init xen_init_debugfs(void)
11 {
12 if (!d_xen_debug) {
13 d_xen_debug = debugfs_create_dir("xen", NULL);
14
15 if (!d_xen_debug)
16 pr_warning("Could not create 'xen' debugfs directory\n");
17 }
18
19 return d_xen_debug;
20 }
21
22 struct array_data
23 {
24 void *array;
25 unsigned elements;
26 };
27
u32_array_open(struct inode * inode,struct file * file)28 static int u32_array_open(struct inode *inode, struct file *file)
29 {
30 file->private_data = NULL;
31 return nonseekable_open(inode, file);
32 }
33
format_array(char * buf,size_t bufsize,const char * fmt,u32 * array,unsigned array_size)34 static size_t format_array(char *buf, size_t bufsize, const char *fmt,
35 u32 *array, unsigned array_size)
36 {
37 size_t ret = 0;
38 unsigned i;
39
40 for(i = 0; i < array_size; i++) {
41 size_t len;
42
43 len = snprintf(buf, bufsize, fmt, array[i]);
44 len++; /* ' ' or '\n' */
45 ret += len;
46
47 if (buf) {
48 buf += len;
49 bufsize -= len;
50 buf[-1] = (i == array_size-1) ? '\n' : ' ';
51 }
52 }
53
54 ret++; /* \0 */
55 if (buf)
56 *buf = '\0';
57
58 return ret;
59 }
60
format_array_alloc(const char * fmt,u32 * array,unsigned array_size)61 static char *format_array_alloc(const char *fmt, u32 *array, unsigned array_size)
62 {
63 size_t len = format_array(NULL, 0, fmt, array, array_size);
64 char *ret;
65
66 ret = kmalloc(len, GFP_KERNEL);
67 if (ret == NULL)
68 return NULL;
69
70 format_array(ret, len, fmt, array, array_size);
71 return ret;
72 }
73
u32_array_read(struct file * file,char __user * buf,size_t len,loff_t * ppos)74 static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
75 loff_t *ppos)
76 {
77 struct inode *inode = file->f_path.dentry->d_inode;
78 struct array_data *data = inode->i_private;
79 size_t size;
80
81 if (*ppos == 0) {
82 if (file->private_data) {
83 kfree(file->private_data);
84 file->private_data = NULL;
85 }
86
87 file->private_data = format_array_alloc("%u", data->array, data->elements);
88 }
89
90 size = 0;
91 if (file->private_data)
92 size = strlen(file->private_data);
93
94 return simple_read_from_buffer(buf, len, ppos, file->private_data, size);
95 }
96
xen_array_release(struct inode * inode,struct file * file)97 static int xen_array_release(struct inode *inode, struct file *file)
98 {
99 kfree(file->private_data);
100
101 return 0;
102 }
103
104 static const struct file_operations u32_array_fops = {
105 .owner = THIS_MODULE,
106 .open = u32_array_open,
107 .release= xen_array_release,
108 .read = u32_array_read,
109 .llseek = no_llseek,
110 };
111
xen_debugfs_create_u32_array(const char * name,umode_t mode,struct dentry * parent,u32 * array,unsigned elements)112 struct dentry *xen_debugfs_create_u32_array(const char *name, umode_t mode,
113 struct dentry *parent,
114 u32 *array, unsigned elements)
115 {
116 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
117
118 if (data == NULL)
119 return NULL;
120
121 data->array = array;
122 data->elements = elements;
123
124 return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
125 }
126