1/*
2 * ARAnyM block device driver
3 *
4 * This file is subject to the terms and conditions of the GNU General Public
5 * License.  See the file COPYING in the main directory of this archive
6 * for more details.
7 */
8
9#include <linux/module.h>
10#include <linux/moduleparam.h>
11#include <linux/init.h>
12
13#include <linux/kernel.h>
14#include <linux/errno.h>
15#include <linux/types.h>
16#include <linux/genhd.h>
17#include <linux/blkdev.h>
18#include <linux/hdreg.h>
19#include <linux/slab.h>
20
21#include <asm/natfeat.h>
22
23static long nfhd_id;
24
25enum {
26	/* emulation entry points */
27	NFHD_READ_WRITE = 10,
28	NFHD_GET_CAPACITY = 14,
29
30	/* skip ACSI devices */
31	NFHD_DEV_OFFSET = 8,
32};
33
34static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
35				  u32 count, u32 buf)
36{
37	return nf_call(nfhd_id + NFHD_READ_WRITE, major, minor, rwflag, recno,
38		       count, buf);
39}
40
41static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
42				    u32 *blocksize)
43{
44	return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor,
45		       virt_to_phys(blocks), virt_to_phys(blocksize));
46}
47
48static LIST_HEAD(nfhd_list);
49
50static int major_num;
51module_param(major_num, int, 0);
52
53struct nfhd_device {
54	struct list_head list;
55	int id;
56	u32 blocks, bsize;
57	int bshift;
58	struct request_queue *queue;
59	struct gendisk *disk;
60};
61
62static void nfhd_make_request(struct request_queue *queue, struct bio *bio)
63{
64	struct nfhd_device *dev = queue->queuedata;
65	struct bio_vec bvec;
66	struct bvec_iter iter;
67	int dir, len, shift;
68	sector_t sec = bio->bi_iter.bi_sector;
69
70	dir = bio_data_dir(bio);
71	shift = dev->bshift;
72	bio_for_each_segment(bvec, bio, iter) {
73		len = bvec.bv_len;
74		len >>= 9;
75		nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
76				bvec_to_phys(&bvec));
77		sec += len;
78	}
79	bio_endio(bio, 0);
80}
81
82static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
83{
84	struct nfhd_device *dev = bdev->bd_disk->private_data;
85
86	geo->cylinders = dev->blocks >> (6 - dev->bshift);
87	geo->heads = 4;
88	geo->sectors = 16;
89
90	return 0;
91}
92
93static const struct block_device_operations nfhd_ops = {
94	.owner	= THIS_MODULE,
95	.getgeo	= nfhd_getgeo,
96};
97
98static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
99{
100	struct nfhd_device *dev;
101	int dev_id = id - NFHD_DEV_OFFSET;
102
103	pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
104		blocks, bsize);
105
106	if (bsize < 512 || (bsize & (bsize - 1))) {
107		pr_warn("nfhd%u: invalid block size\n", dev_id);
108		return -EINVAL;
109	}
110
111	dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
112	if (!dev)
113		goto out;
114
115	dev->id = id;
116	dev->blocks = blocks;
117	dev->bsize = bsize;
118	dev->bshift = ffs(bsize) - 10;
119
120	dev->queue = blk_alloc_queue(GFP_KERNEL);
121	if (dev->queue == NULL)
122		goto free_dev;
123
124	dev->queue->queuedata = dev;
125	blk_queue_make_request(dev->queue, nfhd_make_request);
126	blk_queue_logical_block_size(dev->queue, bsize);
127
128	dev->disk = alloc_disk(16);
129	if (!dev->disk)
130		goto free_queue;
131
132	dev->disk->major = major_num;
133	dev->disk->first_minor = dev_id * 16;
134	dev->disk->fops = &nfhd_ops;
135	dev->disk->private_data = dev;
136	sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
137	set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
138	dev->disk->queue = dev->queue;
139
140	add_disk(dev->disk);
141
142	list_add_tail(&dev->list, &nfhd_list);
143
144	return 0;
145
146free_queue:
147	blk_cleanup_queue(dev->queue);
148free_dev:
149	kfree(dev);
150out:
151	return -ENOMEM;
152}
153
154static int __init nfhd_init(void)
155{
156	u32 blocks, bsize;
157	int i;
158
159	nfhd_id = nf_get_id("XHDI");
160	if (!nfhd_id)
161		return -ENODEV;
162
163	major_num = register_blkdev(major_num, "nfhd");
164	if (major_num <= 0) {
165		pr_warn("nfhd: unable to get major number\n");
166		return major_num;
167	}
168
169	for (i = NFHD_DEV_OFFSET; i < 24; i++) {
170		if (nfhd_get_capacity(i, 0, &blocks, &bsize))
171			continue;
172		nfhd_init_one(i, blocks, bsize);
173	}
174
175	return 0;
176}
177
178static void __exit nfhd_exit(void)
179{
180	struct nfhd_device *dev, *next;
181
182	list_for_each_entry_safe(dev, next, &nfhd_list, list) {
183		list_del(&dev->list);
184		del_gendisk(dev->disk);
185		put_disk(dev->disk);
186		blk_cleanup_queue(dev->queue);
187		kfree(dev);
188	}
189	unregister_blkdev(major_num, "nfhd");
190}
191
192module_init(nfhd_init);
193module_exit(nfhd_exit);
194
195MODULE_LICENSE("GPL");
196