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Commit | Line | Data |
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2611464d | 1 | /* Copyright (c) 2006 Coraid, Inc. See COPYING for GPL terms. */ |
1da177e4 LT |
2 | /* |
3 | * aoechr.c | |
4 | * AoE character device driver | |
5 | */ | |
6 | ||
7 | #include <linux/hdreg.h> | |
8 | #include <linux/blkdev.h> | |
68e0d42f | 9 | #include <linux/delay.h> |
1da177e4 LT |
10 | #include "aoe.h" |
11 | ||
12 | enum { | |
13 | //MINOR_STAT = 1, (moved to sysfs) | |
14 | MINOR_ERR = 2, | |
15 | MINOR_DISCOVER, | |
16 | MINOR_INTERFACES, | |
3ae1c24e | 17 | MINOR_REVALIDATE, |
1da177e4 | 18 | MSGSZ = 2048, |
1da177e4 LT |
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)) { | |
a12c93f0 EC |
59 | printk(KERN_ERR |
60 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
61 | return -EINVAL; |
62 | } | |
63 | return 0; | |
64 | } | |
65 | ||
3ae1c24e EC |
66 | static int |
67 | revalidate(const char __user *str, size_t size) | |
68 | { | |
69 | int major, minor, n; | |
70 | ulong flags; | |
71 | struct aoedev *d; | |
68e0d42f | 72 | struct sk_buff *skb; |
3ae1c24e EC |
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) { | |
a12c93f0 | 84 | printk(KERN_ERR "aoe: invalid device specification\n"); |
3ae1c24e EC |
85 | return -EINVAL; |
86 | } | |
87 | d = aoedev_by_aoeaddr(major, minor); | |
88 | if (!d) | |
89 | return -EINVAL; | |
3ae1c24e | 90 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f EC |
91 | aoecmd_cleanslate(d); |
92 | loop: | |
93 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 94 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
95 | /* try again if we are able to sleep a bit, |
96 | * otherwise give up this revalidation | |
97 | */ | |
98 | if (!skb && !msleep_interruptible(200)) { | |
99 | spin_lock_irqsave(&d->lock, flags); | |
100 | goto loop; | |
101 | } | |
102 | aoenet_xmit(skb); | |
3ae1c24e | 103 | aoecmd_cfg(major, minor); |
3ae1c24e EC |
104 | return 0; |
105 | } | |
106 | ||
1da177e4 LT |
107 | void |
108 | aoechr_error(char *msg) | |
109 | { | |
110 | struct ErrMsg *em; | |
111 | char *mp; | |
112 | ulong flags, n; | |
113 | ||
114 | n = strlen(msg); | |
115 | ||
116 | spin_lock_irqsave(&emsgs_lock, flags); | |
117 | ||
118 | em = emsgs + emsgs_tail_idx; | |
119 | if ((em->flags & EMFL_VALID)) { | |
120 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
121 | return; | |
122 | } | |
123 | ||
124 | mp = kmalloc(n, GFP_ATOMIC); | |
125 | if (mp == NULL) { | |
a12c93f0 | 126 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
127 | goto bail; |
128 | } | |
129 | ||
130 | memcpy(mp, msg, n); | |
131 | em->msg = mp; | |
132 | em->flags |= EMFL_VALID; | |
133 | em->len = n; | |
134 | ||
135 | emsgs_tail_idx++; | |
136 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
137 | ||
138 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
139 | ||
140 | if (nblocked_emsgs_readers) | |
141 | up(&emsgs_sema); | |
142 | } | |
143 | ||
144 | static ssize_t | |
145 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
146 | { | |
147 | int ret = -EINVAL; | |
148 | ||
149 | switch ((unsigned long) filp->private_data) { | |
150 | default: | |
a12c93f0 | 151 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
152 | break; |
153 | case MINOR_DISCOVER: | |
154 | ret = discover(); | |
155 | break; | |
156 | case MINOR_INTERFACES: | |
157 | ret = interfaces(buf, cnt); | |
158 | break; | |
3ae1c24e EC |
159 | case MINOR_REVALIDATE: |
160 | ret = revalidate(buf, cnt); | |
1da177e4 LT |
161 | } |
162 | if (ret == 0) | |
163 | ret = cnt; | |
164 | return ret; | |
165 | } | |
166 | ||
167 | static int | |
168 | aoechr_open(struct inode *inode, struct file *filp) | |
169 | { | |
170 | int n, i; | |
171 | ||
2017b376 | 172 | n = iminor(inode); |
1da177e4 LT |
173 | filp->private_data = (void *) (unsigned long) n; |
174 | ||
175 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
176 | if (chardevs[i].minor == n) | |
177 | return 0; | |
178 | return -EINVAL; | |
179 | } | |
180 | ||
181 | static int | |
182 | aoechr_rel(struct inode *inode, struct file *filp) | |
183 | { | |
184 | return 0; | |
185 | } | |
186 | ||
187 | static ssize_t | |
188 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
189 | { | |
190 | unsigned long n; | |
191 | char *mp; | |
192 | struct ErrMsg *em; | |
193 | ssize_t len; | |
194 | ulong flags; | |
195 | ||
196 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
197 | if (n != MINOR_ERR) |
198 | return -EFAULT; | |
199 | ||
200 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 201 | |
cf446f0d EC |
202 | for (;;) { |
203 | em = emsgs + emsgs_head_idx; | |
204 | if ((em->flags & EMFL_VALID) != 0) | |
205 | break; | |
206 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 207 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
208 | return -EAGAIN; |
209 | } | |
210 | nblocked_emsgs_readers++; | |
211 | ||
212 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 213 | |
cf446f0d | 214 | n = down_interruptible(&emsgs_sema); |
1da177e4 | 215 | |
cf446f0d | 216 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 217 | |
cf446f0d | 218 | nblocked_emsgs_readers--; |
1da177e4 | 219 | |
cf446f0d | 220 | if (n) { |
1da177e4 | 221 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 222 | return -ERESTARTSYS; |
1da177e4 | 223 | } |
cf446f0d EC |
224 | } |
225 | if (em->len > cnt) { | |
226 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
227 | return -EAGAIN; | |
228 | } | |
229 | mp = em->msg; | |
230 | len = em->len; | |
231 | em->msg = NULL; | |
232 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 233 | |
cf446f0d EC |
234 | emsgs_head_idx++; |
235 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 236 | |
cf446f0d | 237 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 238 | |
cf446f0d EC |
239 | n = copy_to_user(buf, mp, len); |
240 | kfree(mp); | |
241 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
242 | } |
243 | ||
2b8693c0 | 244 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
245 | .write = aoechr_write, |
246 | .read = aoechr_read, | |
247 | .open = aoechr_open, | |
248 | .release = aoechr_rel, | |
249 | .owner = THIS_MODULE, | |
250 | }; | |
251 | ||
252 | int __init | |
253 | aoechr_init(void) | |
254 | { | |
255 | int n, i; | |
256 | ||
257 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
258 | if (n < 0) { | |
a12c93f0 | 259 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
260 | return n; |
261 | } | |
262 | sema_init(&emsgs_sema, 0); | |
263 | spin_lock_init(&emsgs_lock); | |
deb36970 | 264 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
265 | if (IS_ERR(aoe_class)) { |
266 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
267 | return PTR_ERR(aoe_class); | |
268 | } | |
269 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 TJ |
270 | device_create(aoe_class, NULL, |
271 | MKDEV(AOE_MAJOR, chardevs[i].minor), chardevs[i].name); | |
1da177e4 LT |
272 | |
273 | return 0; | |
274 | } | |
275 | ||
276 | void | |
277 | aoechr_exit(void) | |
278 | { | |
279 | int i; | |
280 | ||
281 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 282 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 283 | class_destroy(aoe_class); |
1da177e4 LT |
284 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
285 | } | |
286 |