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Commit | Line | Data |
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52e112b3 | 1 | /* Copyright (c) 2007 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, |
262bf541 | 18 | MINOR_FLUSH, |
1da177e4 | 19 | MSGSZ = 2048, |
1da177e4 LT |
20 | NMSG = 100, /* message backlog to retain */ |
21 | }; | |
22 | ||
23 | struct aoe_chardev { | |
24 | ulong minor; | |
25 | char name[32]; | |
26 | }; | |
27 | ||
28 | enum { EMFL_VALID = 1 }; | |
29 | ||
30 | struct ErrMsg { | |
31 | short flags; | |
32 | short len; | |
33 | char *msg; | |
34 | }; | |
35 | ||
36 | static struct ErrMsg emsgs[NMSG]; | |
37 | static int emsgs_head_idx, emsgs_tail_idx; | |
38 | static struct semaphore emsgs_sema; | |
39 | static spinlock_t emsgs_lock; | |
40 | static int nblocked_emsgs_readers; | |
deb36970 | 41 | static struct class *aoe_class; |
1da177e4 LT |
42 | static struct aoe_chardev chardevs[] = { |
43 | { MINOR_ERR, "err" }, | |
44 | { MINOR_DISCOVER, "discover" }, | |
45 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 46 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 47 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
48 | }; |
49 | ||
50 | static int | |
51 | discover(void) | |
52 | { | |
53 | aoecmd_cfg(0xffff, 0xff); | |
54 | return 0; | |
55 | } | |
56 | ||
57 | static int | |
58 | interfaces(const char __user *str, size_t size) | |
59 | { | |
60 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
61 | printk(KERN_ERR |
62 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
63 | return -EINVAL; |
64 | } | |
65 | return 0; | |
66 | } | |
67 | ||
3ae1c24e EC |
68 | static int |
69 | revalidate(const char __user *str, size_t size) | |
70 | { | |
71 | int major, minor, n; | |
72 | ulong flags; | |
73 | struct aoedev *d; | |
68e0d42f | 74 | struct sk_buff *skb; |
3ae1c24e EC |
75 | char buf[16]; |
76 | ||
77 | if (size >= sizeof buf) | |
78 | return -EINVAL; | |
79 | buf[sizeof buf - 1] = '\0'; | |
80 | if (copy_from_user(buf, str, size)) | |
81 | return -EFAULT; | |
82 | ||
83 | /* should be e%d.%d format */ | |
84 | n = sscanf(buf, "e%d.%d", &major, &minor); | |
85 | if (n != 2) { | |
a12c93f0 | 86 | printk(KERN_ERR "aoe: invalid device specification\n"); |
3ae1c24e EC |
87 | return -EINVAL; |
88 | } | |
89 | d = aoedev_by_aoeaddr(major, minor); | |
90 | if (!d) | |
91 | return -EINVAL; | |
3ae1c24e | 92 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f EC |
93 | aoecmd_cleanslate(d); |
94 | loop: | |
95 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 96 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
97 | /* try again if we are able to sleep a bit, |
98 | * otherwise give up this revalidation | |
99 | */ | |
100 | if (!skb && !msleep_interruptible(200)) { | |
101 | spin_lock_irqsave(&d->lock, flags); | |
102 | goto loop; | |
103 | } | |
104 | aoenet_xmit(skb); | |
3ae1c24e | 105 | aoecmd_cfg(major, minor); |
3ae1c24e EC |
106 | return 0; |
107 | } | |
108 | ||
1da177e4 LT |
109 | void |
110 | aoechr_error(char *msg) | |
111 | { | |
112 | struct ErrMsg *em; | |
113 | char *mp; | |
114 | ulong flags, n; | |
115 | ||
116 | n = strlen(msg); | |
117 | ||
118 | spin_lock_irqsave(&emsgs_lock, flags); | |
119 | ||
120 | em = emsgs + emsgs_tail_idx; | |
121 | if ((em->flags & EMFL_VALID)) { | |
122 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
123 | return; | |
124 | } | |
125 | ||
126 | mp = kmalloc(n, GFP_ATOMIC); | |
127 | if (mp == NULL) { | |
a12c93f0 | 128 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
129 | goto bail; |
130 | } | |
131 | ||
132 | memcpy(mp, msg, n); | |
133 | em->msg = mp; | |
134 | em->flags |= EMFL_VALID; | |
135 | em->len = n; | |
136 | ||
137 | emsgs_tail_idx++; | |
138 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
139 | ||
140 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
141 | ||
142 | if (nblocked_emsgs_readers) | |
143 | up(&emsgs_sema); | |
144 | } | |
145 | ||
146 | static ssize_t | |
147 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
148 | { | |
149 | int ret = -EINVAL; | |
150 | ||
151 | switch ((unsigned long) filp->private_data) { | |
152 | default: | |
a12c93f0 | 153 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
154 | break; |
155 | case MINOR_DISCOVER: | |
156 | ret = discover(); | |
157 | break; | |
158 | case MINOR_INTERFACES: | |
159 | ret = interfaces(buf, cnt); | |
160 | break; | |
3ae1c24e EC |
161 | case MINOR_REVALIDATE: |
162 | ret = revalidate(buf, cnt); | |
262bf541 EC |
163 | break; |
164 | case MINOR_FLUSH: | |
165 | ret = aoedev_flush(buf, cnt); | |
1da177e4 LT |
166 | } |
167 | if (ret == 0) | |
168 | ret = cnt; | |
169 | return ret; | |
170 | } | |
171 | ||
172 | static int | |
173 | aoechr_open(struct inode *inode, struct file *filp) | |
174 | { | |
175 | int n, i; | |
176 | ||
2017b376 | 177 | n = iminor(inode); |
1da177e4 LT |
178 | filp->private_data = (void *) (unsigned long) n; |
179 | ||
180 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
181 | if (chardevs[i].minor == n) | |
182 | return 0; | |
183 | return -EINVAL; | |
184 | } | |
185 | ||
186 | static int | |
187 | aoechr_rel(struct inode *inode, struct file *filp) | |
188 | { | |
189 | return 0; | |
190 | } | |
191 | ||
192 | static ssize_t | |
193 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
194 | { | |
195 | unsigned long n; | |
196 | char *mp; | |
197 | struct ErrMsg *em; | |
198 | ssize_t len; | |
199 | ulong flags; | |
200 | ||
201 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
202 | if (n != MINOR_ERR) |
203 | return -EFAULT; | |
204 | ||
205 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 206 | |
cf446f0d EC |
207 | for (;;) { |
208 | em = emsgs + emsgs_head_idx; | |
209 | if ((em->flags & EMFL_VALID) != 0) | |
210 | break; | |
211 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 212 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
213 | return -EAGAIN; |
214 | } | |
215 | nblocked_emsgs_readers++; | |
216 | ||
217 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 218 | |
cf446f0d | 219 | n = down_interruptible(&emsgs_sema); |
1da177e4 | 220 | |
cf446f0d | 221 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 222 | |
cf446f0d | 223 | nblocked_emsgs_readers--; |
1da177e4 | 224 | |
cf446f0d | 225 | if (n) { |
1da177e4 | 226 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 227 | return -ERESTARTSYS; |
1da177e4 | 228 | } |
cf446f0d EC |
229 | } |
230 | if (em->len > cnt) { | |
231 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
232 | return -EAGAIN; | |
233 | } | |
234 | mp = em->msg; | |
235 | len = em->len; | |
236 | em->msg = NULL; | |
237 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 238 | |
cf446f0d EC |
239 | emsgs_head_idx++; |
240 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 241 | |
cf446f0d | 242 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 243 | |
cf446f0d EC |
244 | n = copy_to_user(buf, mp, len); |
245 | kfree(mp); | |
246 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
247 | } |
248 | ||
2b8693c0 | 249 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
250 | .write = aoechr_write, |
251 | .read = aoechr_read, | |
252 | .open = aoechr_open, | |
253 | .release = aoechr_rel, | |
254 | .owner = THIS_MODULE, | |
255 | }; | |
256 | ||
257 | int __init | |
258 | aoechr_init(void) | |
259 | { | |
260 | int n, i; | |
261 | ||
262 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
263 | if (n < 0) { | |
a12c93f0 | 264 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
265 | return n; |
266 | } | |
267 | sema_init(&emsgs_sema, 0); | |
268 | spin_lock_init(&emsgs_lock); | |
deb36970 | 269 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
270 | if (IS_ERR(aoe_class)) { |
271 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
272 | return PTR_ERR(aoe_class); | |
273 | } | |
274 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 TJ |
275 | device_create(aoe_class, NULL, |
276 | MKDEV(AOE_MAJOR, chardevs[i].minor), chardevs[i].name); | |
1da177e4 LT |
277 | |
278 | return 0; | |
279 | } | |
280 | ||
281 | void | |
282 | aoechr_exit(void) | |
283 | { | |
284 | int i; | |
285 | ||
286 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 287 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 288 | class_destroy(aoe_class); |
1da177e4 LT |
289 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
290 | } | |
291 |