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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
27 NFHD_READ_WRITE = 10,
28 NFHD_GET_CAPACITY = 14,
29
30
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 gendisk *disk;
59};
60
61static blk_qc_t nfhd_submit_bio(struct bio *bio)
62{
63 struct nfhd_device *dev = bio->bi_bdev->bd_disk->private_data;
64 struct bio_vec bvec;
65 struct bvec_iter iter;
66 int dir, len, shift;
67 sector_t sec = bio->bi_iter.bi_sector;
68
69 dir = bio_data_dir(bio);
70 shift = dev->bshift;
71 bio_for_each_segment(bvec, bio, iter) {
72 len = bvec.bv_len;
73 len >>= 9;
74 nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
75 page_to_phys(bvec.bv_page) + bvec.bv_offset);
76 sec += len;
77 }
78 bio_endio(bio);
79 return BLK_QC_T_NONE;
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 .submit_bio = nfhd_submit_bio,
96 .getgeo = nfhd_getgeo,
97};
98
99static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
100{
101 struct nfhd_device *dev;
102 int dev_id = id - NFHD_DEV_OFFSET;
103
104 pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
105 blocks, bsize);
106
107 if (bsize < 512 || (bsize & (bsize - 1))) {
108 pr_warn("nfhd%u: invalid block size\n", dev_id);
109 return -EINVAL;
110 }
111
112 dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
113 if (!dev)
114 goto out;
115
116 dev->id = id;
117 dev->blocks = blocks;
118 dev->bsize = bsize;
119 dev->bshift = ffs(bsize) - 10;
120
121 dev->disk = blk_alloc_disk(NUMA_NO_NODE);
122 if (!dev->disk)
123 goto free_dev;
124
125 dev->disk->major = major_num;
126 dev->disk->first_minor = dev_id * 16;
127 dev->disk->minors = 16;
128 dev->disk->fops = &nfhd_ops;
129 dev->disk->private_data = dev;
130 sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
131 set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
132 blk_queue_logical_block_size(dev->disk->queue, bsize);
133 add_disk(dev->disk);
134
135 list_add_tail(&dev->list, &nfhd_list);
136
137 return 0;
138
139free_dev:
140 kfree(dev);
141out:
142 return -ENOMEM;
143}
144
145static int __init nfhd_init(void)
146{
147 u32 blocks, bsize;
148 int ret;
149 int i;
150
151 nfhd_id = nf_get_id("XHDI");
152 if (!nfhd_id)
153 return -ENODEV;
154
155 ret = register_blkdev(major_num, "nfhd");
156 if (ret < 0) {
157 pr_warn("nfhd: unable to get major number\n");
158 return ret;
159 }
160
161 if (!major_num)
162 major_num = ret;
163
164 for (i = NFHD_DEV_OFFSET; i < 24; i++) {
165 if (nfhd_get_capacity(i, 0, &blocks, &bsize))
166 continue;
167 nfhd_init_one(i, blocks, bsize);
168 }
169
170 return 0;
171}
172
173static void __exit nfhd_exit(void)
174{
175 struct nfhd_device *dev, *next;
176
177 list_for_each_entry_safe(dev, next, &nfhd_list, list) {
178 list_del(&dev->list);
179 del_gendisk(dev->disk);
180 blk_cleanup_disk(dev->disk);
181 kfree(dev);
182 }
183 unregister_blkdev(major_num, "nfhd");
184}
185
186module_init(nfhd_init);
187module_exit(nfhd_exit);
188
189MODULE_LICENSE("GPL");
190
