Commit | Line | Data |
---|---|---|
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> | |
24879a8e | 9 | #include <linux/completion.h> |
68e0d42f | 10 | #include <linux/delay.h> |
579174a5 | 11 | #include <linux/smp_lock.h> |
1da177e4 LT |
12 | #include "aoe.h" |
13 | ||
14 | enum { | |
15 | //MINOR_STAT = 1, (moved to sysfs) | |
16 | MINOR_ERR = 2, | |
17 | MINOR_DISCOVER, | |
18 | MINOR_INTERFACES, | |
3ae1c24e | 19 | MINOR_REVALIDATE, |
262bf541 | 20 | MINOR_FLUSH, |
1da177e4 | 21 | MSGSZ = 2048, |
1da177e4 LT |
22 | NMSG = 100, /* message backlog to retain */ |
23 | }; | |
24 | ||
25 | struct aoe_chardev { | |
26 | ulong minor; | |
27 | char name[32]; | |
28 | }; | |
29 | ||
30 | enum { EMFL_VALID = 1 }; | |
31 | ||
32 | struct ErrMsg { | |
33 | short flags; | |
34 | short len; | |
35 | char *msg; | |
36 | }; | |
37 | ||
38 | static struct ErrMsg emsgs[NMSG]; | |
39 | static int emsgs_head_idx, emsgs_tail_idx; | |
24879a8e | 40 | static struct completion emsgs_comp; |
1da177e4 LT |
41 | static spinlock_t emsgs_lock; |
42 | static int nblocked_emsgs_readers; | |
deb36970 | 43 | static struct class *aoe_class; |
1da177e4 LT |
44 | static struct aoe_chardev chardevs[] = { |
45 | { MINOR_ERR, "err" }, | |
46 | { MINOR_DISCOVER, "discover" }, | |
47 | { MINOR_INTERFACES, "interfaces" }, | |
3ae1c24e | 48 | { MINOR_REVALIDATE, "revalidate" }, |
262bf541 | 49 | { MINOR_FLUSH, "flush" }, |
1da177e4 LT |
50 | }; |
51 | ||
52 | static int | |
53 | discover(void) | |
54 | { | |
55 | aoecmd_cfg(0xffff, 0xff); | |
56 | return 0; | |
57 | } | |
58 | ||
59 | static int | |
60 | interfaces(const char __user *str, size_t size) | |
61 | { | |
62 | if (set_aoe_iflist(str, size)) { | |
a12c93f0 EC |
63 | printk(KERN_ERR |
64 | "aoe: could not set interface list: too many interfaces\n"); | |
1da177e4 LT |
65 | return -EINVAL; |
66 | } | |
67 | return 0; | |
68 | } | |
69 | ||
3ae1c24e EC |
70 | static int |
71 | revalidate(const char __user *str, size_t size) | |
72 | { | |
73 | int major, minor, n; | |
74 | ulong flags; | |
75 | struct aoedev *d; | |
68e0d42f | 76 | struct sk_buff *skb; |
3ae1c24e EC |
77 | char buf[16]; |
78 | ||
79 | if (size >= sizeof buf) | |
80 | return -EINVAL; | |
81 | buf[sizeof buf - 1] = '\0'; | |
82 | if (copy_from_user(buf, str, size)) | |
83 | return -EFAULT; | |
84 | ||
85 | /* should be e%d.%d format */ | |
86 | n = sscanf(buf, "e%d.%d", &major, &minor); | |
87 | if (n != 2) { | |
a12c93f0 | 88 | printk(KERN_ERR "aoe: invalid device specification\n"); |
3ae1c24e EC |
89 | return -EINVAL; |
90 | } | |
91 | d = aoedev_by_aoeaddr(major, minor); | |
92 | if (!d) | |
93 | return -EINVAL; | |
3ae1c24e | 94 | spin_lock_irqsave(&d->lock, flags); |
68e0d42f EC |
95 | aoecmd_cleanslate(d); |
96 | loop: | |
97 | skb = aoecmd_ata_id(d); | |
3ae1c24e | 98 | spin_unlock_irqrestore(&d->lock, flags); |
68e0d42f EC |
99 | /* try again if we are able to sleep a bit, |
100 | * otherwise give up this revalidation | |
101 | */ | |
102 | if (!skb && !msleep_interruptible(200)) { | |
103 | spin_lock_irqsave(&d->lock, flags); | |
104 | goto loop; | |
105 | } | |
106 | aoenet_xmit(skb); | |
3ae1c24e | 107 | aoecmd_cfg(major, minor); |
3ae1c24e EC |
108 | return 0; |
109 | } | |
110 | ||
1da177e4 LT |
111 | void |
112 | aoechr_error(char *msg) | |
113 | { | |
114 | struct ErrMsg *em; | |
115 | char *mp; | |
116 | ulong flags, n; | |
117 | ||
118 | n = strlen(msg); | |
119 | ||
120 | spin_lock_irqsave(&emsgs_lock, flags); | |
121 | ||
122 | em = emsgs + emsgs_tail_idx; | |
123 | if ((em->flags & EMFL_VALID)) { | |
124 | bail: spin_unlock_irqrestore(&emsgs_lock, flags); | |
125 | return; | |
126 | } | |
127 | ||
128 | mp = kmalloc(n, GFP_ATOMIC); | |
129 | if (mp == NULL) { | |
a12c93f0 | 130 | printk(KERN_ERR "aoe: allocation failure, len=%ld\n", n); |
1da177e4 LT |
131 | goto bail; |
132 | } | |
133 | ||
134 | memcpy(mp, msg, n); | |
135 | em->msg = mp; | |
136 | em->flags |= EMFL_VALID; | |
137 | em->len = n; | |
138 | ||
139 | emsgs_tail_idx++; | |
140 | emsgs_tail_idx %= ARRAY_SIZE(emsgs); | |
141 | ||
142 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
143 | ||
144 | if (nblocked_emsgs_readers) | |
24879a8e | 145 | complete(&emsgs_comp); |
1da177e4 LT |
146 | } |
147 | ||
148 | static ssize_t | |
149 | aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp) | |
150 | { | |
151 | int ret = -EINVAL; | |
152 | ||
153 | switch ((unsigned long) filp->private_data) { | |
154 | default: | |
a12c93f0 | 155 | printk(KERN_INFO "aoe: can't write to that file.\n"); |
1da177e4 LT |
156 | break; |
157 | case MINOR_DISCOVER: | |
158 | ret = discover(); | |
159 | break; | |
160 | case MINOR_INTERFACES: | |
161 | ret = interfaces(buf, cnt); | |
162 | break; | |
3ae1c24e EC |
163 | case MINOR_REVALIDATE: |
164 | ret = revalidate(buf, cnt); | |
262bf541 EC |
165 | break; |
166 | case MINOR_FLUSH: | |
167 | ret = aoedev_flush(buf, cnt); | |
1da177e4 LT |
168 | } |
169 | if (ret == 0) | |
170 | ret = cnt; | |
171 | return ret; | |
172 | } | |
173 | ||
174 | static int | |
175 | aoechr_open(struct inode *inode, struct file *filp) | |
176 | { | |
177 | int n, i; | |
178 | ||
579174a5 | 179 | lock_kernel(); |
2017b376 | 180 | n = iminor(inode); |
1da177e4 LT |
181 | filp->private_data = (void *) (unsigned long) n; |
182 | ||
183 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
579174a5 JC |
184 | if (chardevs[i].minor == n) { |
185 | unlock_kernel(); | |
1da177e4 | 186 | return 0; |
579174a5 JC |
187 | } |
188 | unlock_kernel(); | |
1da177e4 LT |
189 | return -EINVAL; |
190 | } | |
191 | ||
192 | static int | |
193 | aoechr_rel(struct inode *inode, struct file *filp) | |
194 | { | |
195 | return 0; | |
196 | } | |
197 | ||
198 | static ssize_t | |
199 | aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off) | |
200 | { | |
201 | unsigned long n; | |
202 | char *mp; | |
203 | struct ErrMsg *em; | |
204 | ssize_t len; | |
205 | ulong flags; | |
206 | ||
207 | n = (unsigned long) filp->private_data; | |
cf446f0d EC |
208 | if (n != MINOR_ERR) |
209 | return -EFAULT; | |
210 | ||
211 | spin_lock_irqsave(&emsgs_lock, flags); | |
1da177e4 | 212 | |
cf446f0d EC |
213 | for (;;) { |
214 | em = emsgs + emsgs_head_idx; | |
215 | if ((em->flags & EMFL_VALID) != 0) | |
216 | break; | |
217 | if (filp->f_flags & O_NDELAY) { | |
1da177e4 | 218 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d EC |
219 | return -EAGAIN; |
220 | } | |
221 | nblocked_emsgs_readers++; | |
222 | ||
223 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
1da177e4 | 224 | |
24879a8e | 225 | n = wait_for_completion_interruptible(&emsgs_comp); |
1da177e4 | 226 | |
cf446f0d | 227 | spin_lock_irqsave(&emsgs_lock, flags); |
1da177e4 | 228 | |
cf446f0d | 229 | nblocked_emsgs_readers--; |
1da177e4 | 230 | |
cf446f0d | 231 | if (n) { |
1da177e4 | 232 | spin_unlock_irqrestore(&emsgs_lock, flags); |
cf446f0d | 233 | return -ERESTARTSYS; |
1da177e4 | 234 | } |
cf446f0d EC |
235 | } |
236 | if (em->len > cnt) { | |
237 | spin_unlock_irqrestore(&emsgs_lock, flags); | |
238 | return -EAGAIN; | |
239 | } | |
240 | mp = em->msg; | |
241 | len = em->len; | |
242 | em->msg = NULL; | |
243 | em->flags &= ~EMFL_VALID; | |
1da177e4 | 244 | |
cf446f0d EC |
245 | emsgs_head_idx++; |
246 | emsgs_head_idx %= ARRAY_SIZE(emsgs); | |
1da177e4 | 247 | |
cf446f0d | 248 | spin_unlock_irqrestore(&emsgs_lock, flags); |
1da177e4 | 249 | |
cf446f0d EC |
250 | n = copy_to_user(buf, mp, len); |
251 | kfree(mp); | |
252 | return n == 0 ? len : -EFAULT; | |
1da177e4 LT |
253 | } |
254 | ||
2b8693c0 | 255 | static const struct file_operations aoe_fops = { |
1da177e4 LT |
256 | .write = aoechr_write, |
257 | .read = aoechr_read, | |
258 | .open = aoechr_open, | |
259 | .release = aoechr_rel, | |
260 | .owner = THIS_MODULE, | |
261 | }; | |
262 | ||
263 | int __init | |
264 | aoechr_init(void) | |
265 | { | |
266 | int n, i; | |
267 | ||
268 | n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops); | |
269 | if (n < 0) { | |
a12c93f0 | 270 | printk(KERN_ERR "aoe: can't register char device\n"); |
1da177e4 LT |
271 | return n; |
272 | } | |
24879a8e | 273 | init_completion(&emsgs_comp); |
1da177e4 | 274 | spin_lock_init(&emsgs_lock); |
deb36970 | 275 | aoe_class = class_create(THIS_MODULE, "aoe"); |
1da177e4 LT |
276 | if (IS_ERR(aoe_class)) { |
277 | unregister_chrdev(AOE_MAJOR, "aoechr"); | |
278 | return PTR_ERR(aoe_class); | |
279 | } | |
280 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
f79f0605 GKH |
281 | device_create_drvdata(aoe_class, NULL, |
282 | MKDEV(AOE_MAJOR, chardevs[i].minor), | |
283 | NULL, chardevs[i].name); | |
1da177e4 LT |
284 | |
285 | return 0; | |
286 | } | |
287 | ||
288 | void | |
289 | aoechr_exit(void) | |
290 | { | |
291 | int i; | |
292 | ||
293 | for (i = 0; i < ARRAY_SIZE(chardevs); ++i) | |
7ea7ed01 | 294 | device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor)); |
deb36970 | 295 | class_destroy(aoe_class); |
1da177e4 LT |
296 | unregister_chrdev(AOE_MAJOR, "aoechr"); |
297 | } | |
298 |