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/blkdev.h>
17 #include <linux/hdreg.h>
18 #include <linux/slab.h>
19
20 #include <asm/natfeat.h>
21
22 static long nfhd_id;
23
24 enum {
25 /* emulation entry points */
26 NFHD_READ_WRITE = 10,
27 NFHD_GET_CAPACITY = 14,
28
29 /* skip ACSI devices */
30 NFHD_DEV_OFFSET = 8,
31 };
32
33 static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
34 u32 count, u32 buf)
35 {
36 return nf_call(nfhd_id + NFHD_READ_WRITE, major, minor, rwflag, recno,
37 count, buf);
38 }
39
40 static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
41 u32 *blocksize)
42 {
43 return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor,
44 virt_to_phys(blocks), virt_to_phys(blocksize));
45 }
46
47 static LIST_HEAD(nfhd_list);
48
49 static int major_num;
50 module_param(major_num, int, 0);
51
52 struct nfhd_device {
53 struct list_head list;
54 int id;
55 u32 blocks, bsize;
56 int bshift;
57 struct gendisk *disk;
58 };
59
60 static void nfhd_submit_bio(struct bio *bio)
61 {
62 struct nfhd_device *dev = bio->bi_bdev->bd_disk->private_data;
63 struct bio_vec bvec;
64 struct bvec_iter iter;
65 int dir, len, shift;
66 sector_t sec = bio->bi_iter.bi_sector;
67
68 dir = bio_data_dir(bio);
69 shift = dev->bshift;
70 bio_for_each_segment(bvec, bio, iter) {
71 len = bvec.bv_len;
72 len >>= 9;
73 nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
74 bvec_phys(&bvec));
75 sec += len;
76 }
77 bio_endio(bio);
78 }
79
80 static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
81 {
82 struct nfhd_device *dev = bdev->bd_disk->private_data;
83
84 geo->cylinders = dev->blocks >> (6 - dev->bshift);
85 geo->heads = 4;
86 geo->sectors = 16;
87
88 return 0;
89 }
90
91 static const struct block_device_operations nfhd_ops = {
92 .owner = THIS_MODULE,
93 .submit_bio = nfhd_submit_bio,
94 .getgeo = nfhd_getgeo,
95 };
96
97 static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
98 {
99 struct queue_limits lim = {
100 .logical_block_size = bsize,
101 .features = BLK_FEAT_ROTATIONAL,
102 };
103 struct nfhd_device *dev;
104 int dev_id = id - NFHD_DEV_OFFSET;
105 int err = -ENOMEM;
106
107 pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
108 blocks, bsize);
109
110 if (bsize < 512 || (bsize & (bsize - 1))) {
111 pr_warn("nfhd%u: invalid block size\n", dev_id);
112 return -EINVAL;
113 }
114
115 dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
116 if (!dev)
117 goto out;
118
119 dev->id = id;
120 dev->blocks = blocks;
121 dev->bsize = bsize;
122 dev->bshift = ffs(bsize) - 10;
123
124 dev->disk = blk_alloc_disk(&lim, NUMA_NO_NODE);
125 if (IS_ERR(dev->disk)) {
126 err = PTR_ERR(dev->disk);
127 goto free_dev;
128 }
129
130 dev->disk->major = major_num;
131 dev->disk->first_minor = dev_id * 16;
132 dev->disk->minors = 16;
133 dev->disk->fops = &nfhd_ops;
134 dev->disk->private_data = dev;
135 sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
136 set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
137 err = add_disk(dev->disk);
138 if (err)
139 goto out_cleanup_disk;
140
141 list_add_tail(&dev->list, &nfhd_list);
142
143 return 0;
144
145 out_cleanup_disk:
146 put_disk(dev->disk);
147 free_dev:
148 kfree(dev);
149 out:
150 return err;
151 }
152
153 static int __init nfhd_init(void)
154 {
155 u32 blocks, bsize;
156 int ret;
157 int i;
158
159 nfhd_id = nf_get_id("XHDI");
160 if (!nfhd_id)
161 return -ENODEV;
162
163 ret = register_blkdev(major_num, "nfhd");
164 if (ret < 0) {
165 pr_warn("nfhd: unable to get major number\n");
166 return ret;
167 }
168
169 if (!major_num)
170 major_num = ret;
171
172 for (i = NFHD_DEV_OFFSET; i < 24; i++) {
173 if (nfhd_get_capacity(i, 0, &blocks, &bsize))
174 continue;
175 nfhd_init_one(i, blocks, bsize);
176 }
177
178 return 0;
179 }
180
181 static void __exit nfhd_exit(void)
182 {
183 struct nfhd_device *dev, *next;
184
185 list_for_each_entry_safe(dev, next, &nfhd_list, list) {
186 list_del(&dev->list);
187 del_gendisk(dev->disk);
188 put_disk(dev->disk);
189 kfree(dev);
190 }
191 unregister_blkdev(major_num, "nfhd");
192 }
193
194 module_init(nfhd_init);
195 module_exit(nfhd_exit);
196
197 MODULE_DESCRIPTION("Atari NatFeat block device driver");
198 MODULE_LICENSE("GPL");
199
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