Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* Copyright (c) 2004 Coraid, Inc. See COPYING for GPL terms. */ |
2 | /* | |
3 | * aoechr.c | |
4 | * AoE character device driver | |
5 | */ | |
6 | ||
7 | #include <linux/hdreg.h> | |
8 | #include <linux/blkdev.h> | |
9 | #include "aoe.h" | |
10 | ||
11 | enum { | |
12 | //MINOR_STAT = 1, (moved to sysfs) | |
13 | MINOR_ERR = 2, | |
14 | MINOR_DISCOVER, | |
15 | MINOR_INTERFACES, | |
3ae1c24e | 16 | MINOR_REVALIDATE, |
1da177e4 LT |
17 | MSGSZ = 2048, |
18 | NARGS = 10, | |
19 | NMSG = 100, /* message backlog to retain */ | |
20 | }; | |
21 | ||
22 | struct aoe_chardev { | |
23 | ulong minor; | |
24 | char name[32]; | |
25 | }; | |
26 | ||
27 | enum { EMFL_VALID = 1 }; | |
28 | ||
29 | struct ErrMsg { | |
30 | short flags; | |
31 | short len; | |
32 | char *msg; | |
33 | }; | |
34 | ||
35 | static struct ErrMsg emsgs[NMSG]; | |
36 | static int emsgs_head_idx, emsgs_tail_idx; | |
37 | static struct semaphore emsgs_sema; | |
38 | static spinlock_t emsgs_lock; | |
39 | static int nblocked_emsgs_readers; | |
deb36970 | 40 | static struct class *aoe_class; |
1da177e4 LT |
41 | static struct aoe_chardev chardevs[] = { |
42 | { MINOR_ERR, "err" }, | |
43 | { MINOR_DISCOVER, "discover" }, | |
44 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 45 | { MINOR_REVALIDATE, "revalidate" }, |
1da177e4 LT |
46 | }; |
47 | ||
48 | static int | |
49 | discover(void) | |
50 | { | |
51 | aoecmd_cfg(0xffff, 0xff); | |
52 | return 0; | |
53 | } | |
54 | ||
55 | static int | |
56 | interfaces(const char __user *str, size_t size) | |
57 | { | |
58 | if (set_aoe_iflist(str, size)) { | |
59 | printk(KERN_CRIT | |
60 | "%s: could not set interface list: %s\n", | |
61 | __FUNCTION__, "too many interfaces"); | |
62 | return -EINVAL; | |
63 | } | |
64 | return 0; | |
65 | } | |
66 | ||
3ae1c24e EC |
67 | static int |
68 | revalidate(const char __user *str, size_t size) | |
69 | { | |
70 | int major, minor, n; | |
71 | ulong flags; | |
72 | struct aoedev *d; | |
73 | char buf[16]; | |
74 | ||
75 | if (size >= sizeof buf) | |
76 | return -EINVAL; | |
77 | buf[sizeof buf - 1] = '\0'; | |
78 | if (copy_from_user(buf, str, size)) | |
79 | return -EFAULT; | |
80 | ||
81 | /* should be e%d.%d format */ | |
82 | n = sscanf(buf, "e%d.%d", &major, &minor); | |
83 | if (n != 2) { | |
84 | printk(KERN_ERR "aoe: %s: invalid device specification\n", | |
85 | __FUNCTION__); | |
86 | return -EINVAL; | |
87 | } | |
88 | d = aoedev_by_aoeaddr(major, minor); | |
89 | if (!d) | |
90 | return -EINVAL; | |
91 | ||
92 | spin_lock_irqsave(&d->lock, flags); | |
93 | d->flags |= DEVFL_PAUSE; | |
94 | spin_unlock_irqrestore(&d->lock, flags); | |
95 | aoecmd_cfg(major, minor); | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
1da177e4 LT |
100 | void |
101 | aoechr_error(char *msg) | |
102 | { | |
103 | struct ErrMsg *em; | |
104 | char *mp; | |
105 | ulong flags, n; | |
106 | ||
107 | n = strlen(msg); | |
108 | ||
109 | spin_lock_irqsave(&emsgs_lock, flags); | |
110 | ||
111 | em = emsgs + emsgs_tail_idx; | |
112 | if ((em->flags & EMFL_VALID)) { | |
113 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
114 | return; | |
115 | } | |
116 | ||
117 | mp = kmalloc(n, GFP_ATOMIC); | |
118 | if (mp == NULL) { | |
119 | printk(KERN_CRIT "aoe: aoechr_error: allocation failure, len=%ld\n", n); | |
120 | goto bail; | |
121 | } | |
122 | ||
123 | memcpy(mp, msg, n); | |
124 | em->msg = mp; | |
125 | em->flags |= EMFL_VALID; | |
126 | em->len = n; | |
127 | ||
128 | emsgs_tail_idx++; | |
129 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
130 | ||
131 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
132 | ||
133 | if (nblocked_emsgs_readers) | |
134 | up(&emsgs_sema); | |
135 | } | |
136 | ||
137 | static ssize_t | |
138 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
139 | { | |
140 | int ret = -EINVAL; | |
141 | ||
142 | switch ((unsigned long) filp->private_data) { | |
143 | default: | |
144 | printk(KERN_INFO "aoe: aoechr_write: can't write to that file.\n"); | |
145 | break; | |
146 | case MINOR_DISCOVER: | |
147 | ret = discover(); | |
148 | break; | |
149 | case MINOR_INTERFACES: | |
150 | ret = interfaces(buf, cnt); | |
151 | break; | |
3ae1c24e EC |
152 | case MINOR_REVALIDATE: |
153 | ret = revalidate(buf, cnt); | |
1da177e4 LT |
154 | } |
155 | if (ret == 0) | |
156 | ret = cnt; | |
157 | return ret; | |
158 | } | |
159 | ||
160 | static int | |
161 | aoechr_open(struct inode *inode, struct file *filp) | |
162 | { | |
163 | int n, i; | |
164 | ||
165 | n = MINOR(inode->i_rdev); | |
166 | filp->private_data = (void *) (unsigned long) n; | |
167 | ||
168 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
169 | if (chardevs[i].minor == n) | |
170 | return 0; | |
171 | return -EINVAL; | |
172 | } | |
173 | ||
174 | static int | |
175 | aoechr_rel(struct inode *inode, struct file *filp) | |
176 | { | |
177 | return 0; | |
178 | } | |
179 | ||
180 | static ssize_t | |
181 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
182 | { | |
183 | unsigned long n; | |
184 | char *mp; | |
185 | struct ErrMsg *em; | |
186 | ssize_t len; | |
187 | ulong flags; | |
188 | ||
189 | n = (unsigned long) filp->private_data; | |
190 | switch (n) { | |
191 | case MINOR_ERR: | |
192 | spin_lock_irqsave(&emsgs_lock, flags); | |
193 | loop: | |
194 | em = emsgs + emsgs_head_idx; | |
195 | if ((em->flags & EMFL_VALID) == 0) { | |
196 | if (filp->f_flags & O_NDELAY) { | |
197 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
198 | return -EAGAIN; | |
199 | } | |
200 | nblocked_emsgs_readers++; | |
201 | ||
202 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
203 | ||
204 | n = down_interruptible(&emsgs_sema); | |
205 | ||
206 | spin_lock_irqsave(&emsgs_lock, flags); | |
207 | ||
208 | nblocked_emsgs_readers--; | |
209 | ||
210 | if (n) { | |
211 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
212 | return -ERESTARTSYS; | |
213 | } | |
214 | goto loop; | |
215 | } | |
216 | if (em->len > cnt) { | |
217 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
218 | return -EAGAIN; | |
219 | } | |
220 | mp = em->msg; | |
221 | len = em->len; | |
222 | em->msg = NULL; | |
223 | em->flags &= ~EMFL_VALID; | |
224 | ||
225 | emsgs_head_idx++; | |
226 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
227 | ||
228 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
229 | ||
230 | n = copy_to_user(buf, mp, len); | |
231 | kfree(mp); | |
232 | return n == 0 ? len : -EFAULT; | |
233 | default: | |
234 | return -EFAULT; | |
235 | } | |
236 | } | |
237 | ||
238 | static struct file_operations aoe_fops = { | |
239 | .write = aoechr_write, | |
240 | .read = aoechr_read, | |
241 | .open = aoechr_open, | |
242 | .release = aoechr_rel, | |
243 | .owner = THIS_MODULE, | |
244 | }; | |
245 | ||
246 | int __init | |
247 | aoechr_init(void) | |
248 | { | |
249 | int n, i; | |
250 | ||
251 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
252 | if (n < 0) { | |
253 | printk(KERN_ERR "aoe: aoechr_init: can't register char device\n"); | |
254 | return n; | |
255 | } | |
256 | sema_init(&emsgs_sema, 0); | |
257 | spin_lock_init(&emsgs_lock); | |
deb36970 | 258 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
259 | if (IS_ERR(aoe_class)) { |
260 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
261 | return PTR_ERR(aoe_class); | |
262 | } | |
263 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
53f46542 | 264 | class_device_create(aoe_class, NULL, |
1da177e4 LT |
265 | MKDEV(AOE_MAJOR, chardevs[i].minor), |
266 | NULL, chardevs[i].name); | |
267 | ||
268 | return 0; | |
269 | } | |
270 | ||
271 | void | |
272 | aoechr_exit(void) | |
273 | { | |
274 | int i; | |
275 | ||
276 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
deb36970 | 277 | class_device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
278 | class_destroy(aoe_class); | |
1da177e4 LT |
279 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
280 | } | |
281 |