Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild
[linux-2.6] / drivers / scsi / raid_class.c
1 /*
2  * raid_class.c - implementation of a simple raid visualisation class
3  *
4  * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
5  *
6  * This file is licensed under GPLv2
7  *
8  * This class is designed to allow raid attributes to be visualised and
9  * manipulated in a form independent of the underlying raid.  Ultimately this
10  * should work for both hardware and software raids.
11  */
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/list.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <linux/raid_class.h>
18 #include <scsi/scsi_device.h>
19 #include <scsi/scsi_host.h>
20
21 #define RAID_NUM_ATTRS  3
22
23 struct raid_internal {
24         struct raid_template r;
25         struct raid_function_template *f;
26         /* The actual attributes */
27         struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
28         /* The array of null terminated pointers to attributes 
29          * needed by scsi_sysfs.c */
30         struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
31 };
32
33 struct raid_component {
34         struct list_head node;
35         struct class_device cdev;
36         int num;
37 };
38
39 #define to_raid_internal(tmpl)  container_of(tmpl, struct raid_internal, r)
40
41 #define tc_to_raid_internal(tcont) ({                                   \
42         struct raid_template *r =                                       \
43                 container_of(tcont, struct raid_template, raid_attrs);  \
44         to_raid_internal(r);                                            \
45 })
46
47 #define ac_to_raid_internal(acont) ({                                   \
48         struct transport_container *tc =                                \
49                 container_of(acont, struct transport_container, ac);    \
50         tc_to_raid_internal(tc);                                        \
51 })
52
53 #define class_device_to_raid_internal(cdev) ({                          \
54         struct attribute_container *ac =                                \
55                 attribute_container_classdev_to_container(cdev);        \
56         ac_to_raid_internal(ac);                                        \
57 })
58         
59
60 static int raid_match(struct attribute_container *cont, struct device *dev)
61 {
62         /* We have to look for every subsystem that could house
63          * emulated RAID devices, so start with SCSI */
64         struct raid_internal *i = ac_to_raid_internal(cont);
65
66         if (scsi_is_sdev_device(dev)) {
67                 struct scsi_device *sdev = to_scsi_device(dev);
68
69                 if (i->f->cookie != sdev->host->hostt)
70                         return 0;
71
72                 return i->f->is_raid(dev);
73         }
74         /* FIXME: look at other subsystems too */
75         return 0;
76 }
77
78 static int raid_setup(struct transport_container *tc, struct device *dev,
79                        struct class_device *cdev)
80 {
81         struct raid_data *rd;
82
83         BUG_ON(class_get_devdata(cdev));
84
85         rd = kzalloc(sizeof(*rd), GFP_KERNEL);
86         if (!rd)
87                 return -ENOMEM;
88
89         INIT_LIST_HEAD(&rd->component_list);
90         class_set_devdata(cdev, rd);
91                 
92         return 0;
93 }
94
95 static int raid_remove(struct transport_container *tc, struct device *dev,
96                        struct class_device *cdev)
97 {
98         struct raid_data *rd = class_get_devdata(cdev);
99         struct raid_component *rc, *next;
100         dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
101         class_set_devdata(cdev, NULL);
102         list_for_each_entry_safe(rc, next, &rd->component_list, node) {
103                 list_del(&rc->node);
104                 dev_printk(KERN_ERR, rc->cdev.dev, "RAID COMPONENT REMOVE\n");
105                 class_device_unregister(&rc->cdev);
106         }
107         dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
108         kfree(rd);
109         return 0;
110 }
111
112 static DECLARE_TRANSPORT_CLASS(raid_class,
113                                "raid_devices",
114                                raid_setup,
115                                raid_remove,
116                                NULL);
117
118 static const struct {
119         enum raid_state value;
120         char            *name;
121 } raid_states[] = {
122         { RAID_STATE_UNKNOWN, "unknown" },
123         { RAID_STATE_ACTIVE, "active" },
124         { RAID_STATE_DEGRADED, "degraded" },
125         { RAID_STATE_RESYNCING, "resyncing" },
126         { RAID_STATE_OFFLINE, "offline" },
127 };
128
129 static const char *raid_state_name(enum raid_state state)
130 {
131         int i;
132         char *name = NULL;
133
134         for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
135                 if (raid_states[i].value == state) {
136                         name = raid_states[i].name;
137                         break;
138                 }
139         }
140         return name;
141 }
142
143 static struct {
144         enum raid_level value;
145         char *name;
146 } raid_levels[] = {
147         { RAID_LEVEL_UNKNOWN, "unknown" },
148         { RAID_LEVEL_LINEAR, "linear" },
149         { RAID_LEVEL_0, "raid0" },
150         { RAID_LEVEL_1, "raid1" },
151         { RAID_LEVEL_3, "raid3" },
152         { RAID_LEVEL_4, "raid4" },
153         { RAID_LEVEL_5, "raid5" },
154         { RAID_LEVEL_6, "raid6" },
155 };
156
157 static const char *raid_level_name(enum raid_level level)
158 {
159         int i;
160         char *name = NULL;
161
162         for (i = 0; i < sizeof(raid_levels)/sizeof(raid_levels[0]); i++) {
163                 if (raid_levels[i].value == level) {
164                         name = raid_levels[i].name;
165                         break;
166                 }
167         }
168         return name;
169 }
170
171 #define raid_attr_show_internal(attr, fmt, var, code)                   \
172 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf)   \
173 {                                                                       \
174         struct raid_data *rd = class_get_devdata(cdev);                 \
175         code                                                            \
176         return snprintf(buf, 20, #fmt "\n", var);                       \
177 }
178
179 #define raid_attr_ro_states(attr, states, code)                         \
180 raid_attr_show_internal(attr, %s, name,                                 \
181         const char *name;                                               \
182         code                                                            \
183         name = raid_##states##_name(rd->attr);                          \
184 )                                                                       \
185 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
186
187
188 #define raid_attr_ro_internal(attr, code)                               \
189 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
190 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
191
192 #define ATTR_CODE(attr)                                                 \
193         struct raid_internal *i = class_device_to_raid_internal(cdev);  \
194         if (i->f->get_##attr)                                           \
195                 i->f->get_##attr(cdev->dev);
196
197 #define raid_attr_ro(attr)      raid_attr_ro_internal(attr, )
198 #define raid_attr_ro_fn(attr)   raid_attr_ro_internal(attr, ATTR_CODE(attr))
199 #define raid_attr_ro_state(attr)        raid_attr_ro_states(attr, attr, )
200 #define raid_attr_ro_state_fn(attr)     raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
201
202
203 raid_attr_ro_state(level);
204 raid_attr_ro_fn(resync);
205 raid_attr_ro_state_fn(state);
206
207 static void raid_component_release(struct class_device *cdev)
208 {
209         struct raid_component *rc = container_of(cdev, struct raid_component,
210                                                  cdev);
211         dev_printk(KERN_ERR, rc->cdev.dev, "COMPONENT RELEASE\n");
212         put_device(rc->cdev.dev);
213         kfree(rc);
214 }
215
216 void raid_component_add(struct raid_template *r,struct device *raid_dev,
217                         struct device *component_dev)
218 {
219         struct class_device *cdev =
220                 attribute_container_find_class_device(&r->raid_attrs.ac,
221                                                       raid_dev);
222         struct raid_component *rc;
223         struct raid_data *rd = class_get_devdata(cdev);
224
225         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
226         if (!rc)
227                 return;
228
229         INIT_LIST_HEAD(&rc->node);
230         class_device_initialize(&rc->cdev);
231         rc->cdev.release = raid_component_release;
232         rc->cdev.dev = get_device(component_dev);
233         rc->num = rd->component_count++;
234
235         snprintf(rc->cdev.class_id, sizeof(rc->cdev.class_id),
236                  "component-%d", rc->num);
237         list_add_tail(&rc->node, &rd->component_list);
238         rc->cdev.parent = cdev;
239         rc->cdev.class = &raid_class.class;
240         class_device_add(&rc->cdev);
241 }
242 EXPORT_SYMBOL(raid_component_add);
243
244 struct raid_template *
245 raid_class_attach(struct raid_function_template *ft)
246 {
247         struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
248                                           GFP_KERNEL);
249         int count = 0;
250
251         if (unlikely(!i))
252                 return NULL;
253
254         i->f = ft;
255
256         i->r.raid_attrs.ac.class = &raid_class.class;
257         i->r.raid_attrs.ac.match = raid_match;
258         i->r.raid_attrs.ac.attrs = &i->attrs[0];
259
260         attribute_container_register(&i->r.raid_attrs.ac);
261
262         i->attrs[count++] = &class_device_attr_level;
263         i->attrs[count++] = &class_device_attr_resync;
264         i->attrs[count++] = &class_device_attr_state;
265
266         i->attrs[count] = NULL;
267         BUG_ON(count > RAID_NUM_ATTRS);
268
269         return &i->r;
270 }
271 EXPORT_SYMBOL(raid_class_attach);
272
273 void
274 raid_class_release(struct raid_template *r)
275 {
276         struct raid_internal *i = to_raid_internal(r);
277
278         attribute_container_unregister(&i->r.raid_attrs.ac);
279
280         kfree(i);
281 }
282 EXPORT_SYMBOL(raid_class_release);
283
284 static __init int raid_init(void)
285 {
286         return transport_class_register(&raid_class);
287 }
288
289 static __exit void raid_exit(void)
290 {
291         transport_class_unregister(&raid_class);
292 }
293
294 MODULE_AUTHOR("James Bottomley");
295 MODULE_DESCRIPTION("RAID device class");
296 MODULE_LICENSE("GPL");
297
298 module_init(raid_init);
299 module_exit(raid_exit);
300