1 /* Copyright (c) 2006 Coraid, Inc. See COPYING for GPL terms. */
4 * AoE character device driver
7 #include <linux/hdreg.h>
8 #include <linux/blkdev.h>
12 //MINOR_STAT = 1, (moved to sysfs)
18 NMSG = 100, /* message backlog to retain */
26 enum { EMFL_VALID = 1 };
34 static struct ErrMsg emsgs[NMSG];
35 static int emsgs_head_idx, emsgs_tail_idx;
36 static struct semaphore emsgs_sema;
37 static spinlock_t emsgs_lock;
38 static int nblocked_emsgs_readers;
39 static struct class *aoe_class;
40 static struct aoe_chardev chardevs[] = {
42 { MINOR_DISCOVER, "discover" },
43 { MINOR_INTERFACES, "interfaces" },
44 { MINOR_REVALIDATE, "revalidate" },
50 aoecmd_cfg(0xffff, 0xff);
55 interfaces(const char __user *str, size_t size)
57 if (set_aoe_iflist(str, size)) {
58 eprintk("could not set interface list: too many interfaces\n");
65 revalidate(const char __user *str, size_t size)
72 if (size >= sizeof buf)
74 buf[sizeof buf - 1] = '\0';
75 if (copy_from_user(buf, str, size))
78 /* should be e%d.%d format */
79 n = sscanf(buf, "e%d.%d", &major, &minor);
81 eprintk("invalid device specification\n");
84 d = aoedev_by_aoeaddr(major, minor);
88 spin_lock_irqsave(&d->lock, flags);
89 d->flags &= ~DEVFL_MAXBCNT;
90 d->flags |= DEVFL_PAUSE;
91 spin_unlock_irqrestore(&d->lock, flags);
92 aoecmd_cfg(major, minor);
98 aoechr_error(char *msg)
106 spin_lock_irqsave(&emsgs_lock, flags);
108 em = emsgs + emsgs_tail_idx;
109 if ((em->flags & EMFL_VALID)) {
110 bail: spin_unlock_irqrestore(&emsgs_lock, flags);
114 mp = kmalloc(n, GFP_ATOMIC);
116 eprintk("allocation failure, len=%ld\n", n);
122 em->flags |= EMFL_VALID;
126 emsgs_tail_idx %= ARRAY_SIZE(emsgs);
128 spin_unlock_irqrestore(&emsgs_lock, flags);
130 if (nblocked_emsgs_readers)
135 aoechr_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offp)
139 switch ((unsigned long) filp->private_data) {
141 iprintk("can't write to that file.\n");
146 case MINOR_INTERFACES:
147 ret = interfaces(buf, cnt);
149 case MINOR_REVALIDATE:
150 ret = revalidate(buf, cnt);
158 aoechr_open(struct inode *inode, struct file *filp)
163 filp->private_data = (void *) (unsigned long) n;
165 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
166 if (chardevs[i].minor == n)
172 aoechr_rel(struct inode *inode, struct file *filp)
178 aoechr_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
186 n = (unsigned long) filp->private_data;
189 spin_lock_irqsave(&emsgs_lock, flags);
191 em = emsgs + emsgs_head_idx;
192 if ((em->flags & EMFL_VALID) == 0) {
193 if (filp->f_flags & O_NDELAY) {
194 spin_unlock_irqrestore(&emsgs_lock, flags);
197 nblocked_emsgs_readers++;
199 spin_unlock_irqrestore(&emsgs_lock, flags);
201 n = down_interruptible(&emsgs_sema);
203 spin_lock_irqsave(&emsgs_lock, flags);
205 nblocked_emsgs_readers--;
208 spin_unlock_irqrestore(&emsgs_lock, flags);
214 spin_unlock_irqrestore(&emsgs_lock, flags);
220 em->flags &= ~EMFL_VALID;
223 emsgs_head_idx %= ARRAY_SIZE(emsgs);
225 spin_unlock_irqrestore(&emsgs_lock, flags);
227 n = copy_to_user(buf, mp, len);
229 return n == 0 ? len : -EFAULT;
235 static struct file_operations aoe_fops = {
236 .write = aoechr_write,
239 .release = aoechr_rel,
240 .owner = THIS_MODULE,
248 n = register_chrdev(AOE_MAJOR, "aoechr", &aoe_fops);
250 eprintk("can't register char device\n");
253 sema_init(&emsgs_sema, 0);
254 spin_lock_init(&emsgs_lock);
255 aoe_class = class_create(THIS_MODULE, "aoe");
256 if (IS_ERR(aoe_class)) {
257 unregister_chrdev(AOE_MAJOR, "aoechr");
258 return PTR_ERR(aoe_class);
260 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
261 class_device_create(aoe_class, NULL,
262 MKDEV(AOE_MAJOR, chardevs[i].minor),
263 NULL, chardevs[i].name);
273 for (i = 0; i < ARRAY_SIZE(chardevs); ++i)
274 class_device_destroy(aoe_class, MKDEV(AOE_MAJOR, chardevs[i].minor));
275 class_destroy(aoe_class);
276 unregister_chrdev(AOE_MAJOR, "aoechr");