V4L/DVB (8930): gspca: The image transfer by bulk is started by the subdrivers.
[linux-2.6] / kernel / ksysfs.c
1 /*
2  * kernel/ksysfs.c - sysfs attributes in /sys/kernel, which
3  *                   are not related to any other subsystem
4  *
5  * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
6  * 
7  * This file is release under the GPLv2
8  *
9  */
10
11 #include <linux/kobject.h>
12 #include <linux/string.h>
13 #include <linux/sysfs.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/kexec.h>
17 #include <linux/sched.h>
18
19 #define KERNEL_ATTR_RO(_name) \
20 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
21
22 #define KERNEL_ATTR_RW(_name) \
23 static struct kobj_attribute _name##_attr = \
24         __ATTR(_name, 0644, _name##_show, _name##_store)
25
26 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
27 /* current uevent sequence number */
28 static ssize_t uevent_seqnum_show(struct kobject *kobj,
29                                   struct kobj_attribute *attr, char *buf)
30 {
31         return sprintf(buf, "%llu\n", (unsigned long long)uevent_seqnum);
32 }
33 KERNEL_ATTR_RO(uevent_seqnum);
34
35 /* uevent helper program, used during early boo */
36 static ssize_t uevent_helper_show(struct kobject *kobj,
37                                   struct kobj_attribute *attr, char *buf)
38 {
39         return sprintf(buf, "%s\n", uevent_helper);
40 }
41 static ssize_t uevent_helper_store(struct kobject *kobj,
42                                    struct kobj_attribute *attr,
43                                    const char *buf, size_t count)
44 {
45         if (count+1 > UEVENT_HELPER_PATH_LEN)
46                 return -ENOENT;
47         memcpy(uevent_helper, buf, count);
48         uevent_helper[count] = '\0';
49         if (count && uevent_helper[count-1] == '\n')
50                 uevent_helper[count-1] = '\0';
51         return count;
52 }
53 KERNEL_ATTR_RW(uevent_helper);
54 #endif
55
56 #ifdef CONFIG_KEXEC
57 static ssize_t kexec_loaded_show(struct kobject *kobj,
58                                  struct kobj_attribute *attr, char *buf)
59 {
60         return sprintf(buf, "%d\n", !!kexec_image);
61 }
62 KERNEL_ATTR_RO(kexec_loaded);
63
64 static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
65                                        struct kobj_attribute *attr, char *buf)
66 {
67         return sprintf(buf, "%d\n", !!kexec_crash_image);
68 }
69 KERNEL_ATTR_RO(kexec_crash_loaded);
70
71 static ssize_t vmcoreinfo_show(struct kobject *kobj,
72                                struct kobj_attribute *attr, char *buf)
73 {
74         return sprintf(buf, "%lx %x\n",
75                        paddr_vmcoreinfo_note(),
76                        (unsigned int)vmcoreinfo_max_size);
77 }
78 KERNEL_ATTR_RO(vmcoreinfo);
79
80 #endif /* CONFIG_KEXEC */
81
82 /*
83  * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
84  */
85 extern const void __start_notes __attribute__((weak));
86 extern const void __stop_notes __attribute__((weak));
87 #define notes_size (&__stop_notes - &__start_notes)
88
89 static ssize_t notes_read(struct kobject *kobj, struct bin_attribute *bin_attr,
90                           char *buf, loff_t off, size_t count)
91 {
92         memcpy(buf, &__start_notes + off, count);
93         return count;
94 }
95
96 static struct bin_attribute notes_attr = {
97         .attr = {
98                 .name = "notes",
99                 .mode = S_IRUGO,
100         },
101         .read = &notes_read,
102 };
103
104 struct kobject *kernel_kobj;
105 EXPORT_SYMBOL_GPL(kernel_kobj);
106
107 static struct attribute * kernel_attrs[] = {
108 #if defined(CONFIG_HOTPLUG) && defined(CONFIG_NET)
109         &uevent_seqnum_attr.attr,
110         &uevent_helper_attr.attr,
111 #endif
112 #ifdef CONFIG_KEXEC
113         &kexec_loaded_attr.attr,
114         &kexec_crash_loaded_attr.attr,
115         &vmcoreinfo_attr.attr,
116 #endif
117         NULL
118 };
119
120 static struct attribute_group kernel_attr_group = {
121         .attrs = kernel_attrs,
122 };
123
124 static int __init ksysfs_init(void)
125 {
126         int error;
127
128         kernel_kobj = kobject_create_and_add("kernel", NULL);
129         if (!kernel_kobj) {
130                 error = -ENOMEM;
131                 goto exit;
132         }
133         error = sysfs_create_group(kernel_kobj, &kernel_attr_group);
134         if (error)
135                 goto kset_exit;
136
137         if (notes_size > 0) {
138                 notes_attr.size = notes_size;
139                 error = sysfs_create_bin_file(kernel_kobj, &notes_attr);
140                 if (error)
141                         goto group_exit;
142         }
143
144         /* create the /sys/kernel/uids/ directory */
145         error = uids_sysfs_init();
146         if (error)
147                 goto notes_exit;
148
149         return 0;
150
151 notes_exit:
152         if (notes_size > 0)
153                 sysfs_remove_bin_file(kernel_kobj, &notes_attr);
154 group_exit:
155         sysfs_remove_group(kernel_kobj, &kernel_attr_group);
156 kset_exit:
157         kobject_put(kernel_kobj);
158 exit:
159         return error;
160 }
161
162 core_initcall(ksysfs_init);