1/* Copyright (c) 2006 Coraid, Inc.  See COPYING for GPL terms. */
2/*
3 * aoedev.c
4 * AoE device utility functions; maintains device list.
5 */
6
7#include <linux/hdreg.h>
8#include <linux/blkdev.h>
9#include <linux/netdevice.h>
10#include "aoe.h"
11
12static struct aoedev *devlist;
13static spinlock_t devlist_lock;
14
15int
16aoedev_isbusy(struct aoedev *d)
17{
18	struct frame *f, *e;
19
20	f = d->frames;
21	e = f + d->nframes;
22	do {
23		if (f->tag != FREETAG)
24			return 1;
25	} while (++f < e);
26
27	return 0;
28}
29
30struct aoedev *
31aoedev_by_aoeaddr(int maj, int min)
32{
33	struct aoedev *d;
34	ulong flags;
35
36	spin_lock_irqsave(&devlist_lock, flags);
37
38	for (d=devlist; d; d=d->next)
39		if (d->aoemajor == maj && d->aoeminor == min)
40			break;
41
42	spin_unlock_irqrestore(&devlist_lock, flags);
43	return d;
44}
45
46static void
47dummy_timer(ulong vp)
48{
49	struct aoedev *d;
50
51	d = (struct aoedev *)vp;
52	if (d->flags & DEVFL_TKILL)
53		return;
54	d->timer.expires = jiffies + HZ;
55	add_timer(&d->timer);
56}
57
58/* called with devlist lock held */
59static struct aoedev *
60aoedev_newdev(ulong nframes)
61{
62	struct aoedev *d;
63	struct frame *f, *e;
64
65	d = kzalloc(sizeof *d, GFP_ATOMIC);
66	f = kcalloc(nframes, sizeof *f, GFP_ATOMIC);
67 	switch (!d || !f) {
68 	case 0:
69 		d->nframes = nframes;
70 		d->frames = f;
71 		e = f + nframes;
72 		for (; f<e; f++) {
73 			f->tag = FREETAG;
74 			f->skb = new_skb(ETH_ZLEN);
75 			if (!f->skb)
76 				break;
77 		}
78 		if (f == e)
79 			break;
80 		while (f > d->frames) {
81 			f--;
82 			dev_kfree_skb(f->skb);
83 		}
84 	default:
85 		if (f)
86 			kfree(f);
87 		if (d)
88 			kfree(d);
89		return NULL;
90	}
91	INIT_WORK(&d->work, aoecmd_sleepwork);
92	spin_lock_init(&d->lock);
93	init_timer(&d->timer);
94	d->timer.data = (ulong) d;
95	d->timer.function = dummy_timer;
96	d->timer.expires = jiffies + HZ;
97	add_timer(&d->timer);
98	d->bufpool = NULL;	/* defer to aoeblk_gdalloc */
99	INIT_LIST_HEAD(&d->bufq);
100	d->next = devlist;
101	devlist = d;
102
103	return d;
104}
105
106void
107aoedev_downdev(struct aoedev *d)
108{
109	struct frame *f, *e;
110	struct buf *buf;
111	struct bio *bio;
112
113	f = d->frames;
114	e = f + d->nframes;
115	for (; f<e; f->tag = FREETAG, f->buf = NULL, f++) {
116		if (f->tag == FREETAG || f->buf == NULL)
117			continue;
118		buf = f->buf;
119		bio = buf->bio;
120		if (--buf->nframesout == 0) {
121			mempool_free(buf, d->bufpool);
122			bio_endio(bio, bio->bi_size, -EIO);
123		}
124		skb_shinfo(f->skb)->nr_frags = f->skb->data_len = 0;
125	}
126	d->inprocess = NULL;
127
128	while (!list_empty(&d->bufq)) {
129		buf = container_of(d->bufq.next, struct buf, bufs);
130		list_del(d->bufq.next);
131		bio = buf->bio;
132		mempool_free(buf, d->bufpool);
133		bio_endio(bio, bio->bi_size, -EIO);
134	}
135
136	if (d->gd)
137		d->gd->capacity = 0;
138
139	d->flags &= ~(DEVFL_UP | DEVFL_PAUSE);
140}
141
142/* find it or malloc it */
143struct aoedev *
144aoedev_by_sysminor_m(ulong sysminor, ulong bufcnt)
145{
146	struct aoedev *d;
147	ulong flags;
148
149	spin_lock_irqsave(&devlist_lock, flags);
150
151	for (d=devlist; d; d=d->next)
152		if (d->sysminor == sysminor)
153			break;
154
155	if (d == NULL) {
156		d = aoedev_newdev(bufcnt);
157	 	if (d == NULL) {
158			spin_unlock_irqrestore(&devlist_lock, flags);
159			printk(KERN_INFO "aoe: aoedev_newdev failure.\n");
160			return NULL;
161		}
162		d->sysminor = sysminor;
163		d->aoemajor = AOEMAJOR(sysminor);
164		d->aoeminor = AOEMINOR(sysminor);
165	}
166
167	spin_unlock_irqrestore(&devlist_lock, flags);
168	return d;
169}
170
171static void
172aoedev_freedev(struct aoedev *d)
173{
174	struct frame *f, *e;
175
176	if (d->gd) {
177		aoedisk_rm_sysfs(d);
178		del_gendisk(d->gd);
179		put_disk(d->gd);
180	}
181	f = d->frames;
182	e = f + d->nframes;
183	for (; f<e; f++) {
184		skb_shinfo(f->skb)->nr_frags = 0;
185		dev_kfree_skb(f->skb);
186	}
187	kfree(d->frames);
188	if (d->bufpool)
189		mempool_destroy(d->bufpool);
190	kfree(d);
191}
192
193void
194aoedev_exit(void)
195{
196	struct aoedev *d;
197	ulong flags;
198
199	flush_scheduled_work();
200
201	while ((d = devlist)) {
202		devlist = d->next;
203
204		spin_lock_irqsave(&d->lock, flags);
205		aoedev_downdev(d);
206		d->flags |= DEVFL_TKILL;
207		spin_unlock_irqrestore(&d->lock, flags);
208
209		del_timer_sync(&d->timer);
210		aoedev_freedev(d);
211	}
212}
213
214int __init
215aoedev_init(void)
216{
217	spin_lock_init(&devlist_lock);
218	return 0;
219}
220