xref: /openbmc/linux/arch/m68k/emu/nfblock.c (revision 8b9ab626)
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 	put_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 		put_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