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 page_to_phys(bvec.bv_page) + bvec.bv_offset); 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 }; 102 struct nfhd_device *dev; 103 int dev_id = id - NFHD_DEV_OFFSET; 104 int err = -ENOMEM; 105 106 pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id, 107 blocks, bsize); 108 109 if (bsize < 512 || (bsize & (bsize - 1))) { 110 pr_warn("nfhd%u: invalid block size\n", dev_id); 111 return -EINVAL; 112 } 113 114 dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL); 115 if (!dev) 116 goto out; 117 118 dev->id = id; 119 dev->blocks = blocks; 120 dev->bsize = bsize; 121 dev->bshift = ffs(bsize) - 10; 122 123 dev->disk = blk_alloc_disk(&lim, NUMA_NO_NODE); 124 if (IS_ERR(dev->disk)) { 125 err = PTR_ERR(dev->disk); 126 goto free_dev; 127 } 128 129 dev->disk->major = major_num; 130 dev->disk->first_minor = dev_id * 16; 131 dev->disk->minors = 16; 132 dev->disk->fops = &nfhd_ops; 133 dev->disk->private_data = dev; 134 sprintf(dev->disk->disk_name, "nfhd%u", dev_id); 135 set_capacity(dev->disk, (sector_t)blocks * (bsize / 512)); 136 err = add_disk(dev->disk); 137 if (err) 138 goto out_cleanup_disk; 139 140 list_add_tail(&dev->list, &nfhd_list); 141 142 return 0; 143 144 out_cleanup_disk: 145 put_disk(dev->disk); 146 free_dev: 147 kfree(dev); 148 out: 149 return err; 150 } 151 152 static int __init nfhd_init(void) 153 { 154 u32 blocks, bsize; 155 int ret; 156 int i; 157 158 nfhd_id = nf_get_id("XHDI"); 159 if (!nfhd_id) 160 return -ENODEV; 161 162 ret = register_blkdev(major_num, "nfhd"); 163 if (ret < 0) { 164 pr_warn("nfhd: unable to get major number\n"); 165 return ret; 166 } 167 168 if (!major_num) 169 major_num = ret; 170 171 for (i = NFHD_DEV_OFFSET; i < 24; i++) { 172 if (nfhd_get_capacity(i, 0, &blocks, &bsize)) 173 continue; 174 nfhd_init_one(i, blocks, bsize); 175 } 176 177 return 0; 178 } 179 180 static void __exit nfhd_exit(void) 181 { 182 struct nfhd_device *dev, *next; 183 184 list_for_each_entry_safe(dev, next, &nfhd_list, list) { 185 list_del(&dev->list); 186 del_gendisk(dev->disk); 187 put_disk(dev->disk); 188 kfree(dev); 189 } 190 unregister_blkdev(major_num, "nfhd"); 191 } 192 193 module_init(nfhd_init); 194 module_exit(nfhd_exit); 195 196 MODULE_LICENSE("GPL"); 197