summaryrefslogtreecommitdiff
path: root/arch/m68k/emu/nfblock.c
blob: 48e50f8c1c7e07f10d2ac4a400f763585f45a7d1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
/*
 * ARAnyM block device driver
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/slab.h>

#include <asm/natfeat.h>

static long nfhd_id;

enum {
	/* emulation entry points */
	NFHD_READ_WRITE = 10,
	NFHD_GET_CAPACITY = 14,

	/* skip ACSI devices */
	NFHD_DEV_OFFSET = 8,
};

static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
				  u32 count, u32 buf)
{
	return nf_call(nfhd_id + NFHD_READ_WRITE, major, minor, rwflag, recno,
		       count, buf);
}

static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
				    u32 *blocksize)
{
	return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor, blocks,
		       blocksize);
}

static LIST_HEAD(nfhd_list);

static int major_num;
module_param(major_num, int, 0);

struct nfhd_device {
	struct list_head list;
	int id;
	u32 blocks, bsize;
	int bshift;
	struct request_queue *queue;
	struct gendisk *disk;
};

static int nfhd_make_request(struct request_queue *queue, struct bio *bio)
{
	struct nfhd_device *dev = queue->queuedata;
	struct bio_vec *bvec;
	int i, dir, len, shift;
	sector_t sec = bio->bi_sector;

	dir = bio_data_dir(bio);
	shift = dev->bshift;
	bio_for_each_segment(bvec, bio, i) {
		len = bvec->bv_len;
		len >>= 9;
		nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
				bvec_to_phys(bvec));
		sec += len;
	}
	bio_endio(bio, 0);
	return 0;
}

static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct nfhd_device *dev = bdev->bd_disk->private_data;

	geo->cylinders = dev->blocks >> (6 - dev->bshift);
	geo->heads = 4;
	geo->sectors = 16;

	return 0;
}

static const struct block_device_operations nfhd_ops = {
	.owner	= THIS_MODULE,
	.getgeo	= nfhd_getgeo,
};

static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
{
	struct nfhd_device *dev;
	int dev_id = id - NFHD_DEV_OFFSET;

	pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
		blocks, bsize);

	if (bsize < 512 || (bsize & (bsize - 1))) {
		pr_warn("nfhd%u: invalid block size\n", dev_id);
		return -EINVAL;
	}

	dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
	if (!dev)
		goto out;

	dev->id = id;
	dev->blocks = blocks;
	dev->bsize = bsize;
	dev->bshift = ffs(bsize) - 10;

	dev->queue = blk_alloc_queue(GFP_KERNEL);
	if (dev->queue == NULL)
		goto free_dev;

	dev->queue->queuedata = dev;
	blk_queue_make_request(dev->queue, nfhd_make_request);
	blk_queue_logical_block_size(dev->queue, bsize);

	dev->disk = alloc_disk(16);
	if (!dev->disk)
		goto free_queue;

	dev->disk->major = major_num;
	dev->disk->first_minor = dev_id * 16;
	dev->disk->fops = &nfhd_ops;
	dev->disk->private_data = dev;
	sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
	set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
	dev->disk->queue = dev->queue;

	add_disk(dev->disk);

	list_add_tail(&dev->list, &nfhd_list);

	return 0;

free_queue:
	blk_cleanup_queue(dev->queue);
free_dev:
	kfree(dev);
out:
	return -ENOMEM;
}

static int __init nfhd_init(void)
{
	u32 blocks, bsize;
	int i;

	nfhd_id = nf_get_id("XHDI");
	if (!nfhd_id)
		return -ENODEV;

	major_num = register_blkdev(major_num, "nfhd");
	if (major_num <= 0) {
		pr_warn("nfhd: unable to get major number\n");
		return major_num;
	}

	for (i = NFHD_DEV_OFFSET; i < 24; i++) {
		if (nfhd_get_capacity(i, 0, &blocks, &bsize))
			continue;
		nfhd_init_one(i, blocks, bsize);
	}

	return 0;
}

static void __exit nfhd_exit(void)
{
	struct nfhd_device *dev, *next;

	list_for_each_entry_safe(dev, next, &nfhd_list, list) {
		list_del(&dev->list);
		del_gendisk(dev->disk);
		put_disk(dev->disk);
		blk_cleanup_queue(dev->queue);
		kfree(dev);
	}
	unregister_blkdev(major_num, "nfhd");
}

module_init(nfhd_init);
module_exit(nfhd_exit);

MODULE_LICENSE("GPL");