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
nfhd_read_write(u32 major,u32 minor,u32 rwflag,u32 recno,u32 count,u32 buf)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
nfhd_get_capacity(u32 major,u32 minor,u32 * blocks,u32 * blocksize)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
nfhd_submit_bio(struct bio * bio)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 page_to_phys(bvec.bv_page) + bvec.bv_offset);
75 sec += len;
76 }
77 bio_endio(bio);
78 }
79
nfhd_getgeo(struct block_device * bdev,struct hd_geometry * geo)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
nfhd_init_one(int id,u32 blocks,u32 bsize)97 static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
98 {
99 struct nfhd_device *dev;
100 int dev_id = id - NFHD_DEV_OFFSET;
101 int err = -ENOMEM;
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->disk = blk_alloc_disk(NUMA_NO_NODE);
121 if (!dev->disk)
122 goto free_dev;
123
124 dev->disk->major = major_num;
125 dev->disk->first_minor = dev_id * 16;
126 dev->disk->minors = 16;
127 dev->disk->fops = &nfhd_ops;
128 dev->disk->private_data = dev;
129 sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
130 set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
131 blk_queue_logical_block_size(dev->disk->queue, bsize);
132 err = add_disk(dev->disk);
133 if (err)
134 goto out_cleanup_disk;
135
136 list_add_tail(&dev->list, &nfhd_list);
137
138 return 0;
139
140 out_cleanup_disk:
141 blk_cleanup_disk(dev->disk);
142 free_dev:
143 kfree(dev);
144 out:
145 return err;
146 }
147
nfhd_init(void)148 static int __init nfhd_init(void)
149 {
150 u32 blocks, bsize;
151 int ret;
152 int i;
153
154 nfhd_id = nf_get_id("XHDI");
155 if (!nfhd_id)
156 return -ENODEV;
157
158 ret = register_blkdev(major_num, "nfhd");
159 if (ret < 0) {
160 pr_warn("nfhd: unable to get major number\n");
161 return ret;
162 }
163
164 if (!major_num)
165 major_num = ret;
166
167 for (i = NFHD_DEV_OFFSET; i < 24; i++) {
168 if (nfhd_get_capacity(i, 0, &blocks, &bsize))
169 continue;
170 nfhd_init_one(i, blocks, bsize);
171 }
172
173 return 0;
174 }
175
nfhd_exit(void)176 static void __exit nfhd_exit(void)
177 {
178 struct nfhd_device *dev, *next;
179
180 list_for_each_entry_safe(dev, next, &nfhd_list, list) {
181 list_del(&dev->list);
182 del_gendisk(dev->disk);
183 blk_cleanup_disk(dev->disk);
184 kfree(dev);
185 }
186 unregister_blkdev(major_num, "nfhd");
187 }
188
189 module_init(nfhd_init);
190 module_exit(nfhd_exit);
191
192 MODULE_LICENSE("GPL");
193