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/genhd.h> 17 #include <linux/blkdev.h> 18 #include <linux/hdreg.h> 19 #include <linux/slab.h> 20 21 #include <asm/natfeat.h> 22 23 static long nfhd_id; 24 25 enum { 26 /* emulation entry points */ 27 NFHD_READ_WRITE = 10, 28 NFHD_GET_CAPACITY = 14, 29 30 /* skip ACSI devices */ 31 NFHD_DEV_OFFSET = 8, 32 }; 33 34 static 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 41 static 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 48 static LIST_HEAD(nfhd_list); 49 50 static int major_num; 51 module_param(major_num, int, 0); 52 53 struct nfhd_device { 54 struct list_head list; 55 int id; 56 u32 blocks, bsize; 57 int bshift; 58 struct request_queue *queue; 59 struct gendisk *disk; 60 }; 61 62 static blk_qc_t nfhd_make_request(struct request_queue *queue, struct bio *bio) 63 { 64 struct nfhd_device *dev = queue->queuedata; 65 struct bio_vec bvec; 66 struct bvec_iter iter; 67 int dir, len, shift; 68 sector_t sec = bio->bi_iter.bi_sector; 69 70 dir = bio_data_dir(bio); 71 shift = dev->bshift; 72 bio_for_each_segment(bvec, bio, iter) { 73 len = bvec.bv_len; 74 len >>= 9; 75 nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift, 76 bvec_to_phys(&bvec)); 77 sec += len; 78 } 79 bio_endio(bio); 80 return BLK_QC_T_NONE; 81 } 82 83 static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo) 84 { 85 struct nfhd_device *dev = bdev->bd_disk->private_data; 86 87 geo->cylinders = dev->blocks >> (6 - dev->bshift); 88 geo->heads = 4; 89 geo->sectors = 16; 90 91 return 0; 92 } 93 94 static const struct block_device_operations nfhd_ops = { 95 .owner = THIS_MODULE, 96 .getgeo = nfhd_getgeo, 97 }; 98 99 static 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->queue = blk_alloc_queue(GFP_KERNEL); 122 if (dev->queue == NULL) 123 goto free_dev; 124 125 dev->queue->queuedata = dev; 126 blk_queue_make_request(dev->queue, nfhd_make_request); 127 blk_queue_logical_block_size(dev->queue, bsize); 128 129 dev->disk = alloc_disk(16); 130 if (!dev->disk) 131 goto free_queue; 132 133 dev->disk->major = major_num; 134 dev->disk->first_minor = dev_id * 16; 135 dev->disk->fops = &nfhd_ops; 136 dev->disk->private_data = dev; 137 sprintf(dev->disk->disk_name, "nfhd%u", dev_id); 138 set_capacity(dev->disk, (sector_t)blocks * (bsize / 512)); 139 dev->disk->queue = dev->queue; 140 141 add_disk(dev->disk); 142 143 list_add_tail(&dev->list, &nfhd_list); 144 145 return 0; 146 147 free_queue: 148 blk_cleanup_queue(dev->queue); 149 free_dev: 150 kfree(dev); 151 out: 152 return -ENOMEM; 153 } 154 155 static int __init nfhd_init(void) 156 { 157 u32 blocks, bsize; 158 int i; 159 160 nfhd_id = nf_get_id("XHDI"); 161 if (!nfhd_id) 162 return -ENODEV; 163 164 major_num = register_blkdev(major_num, "nfhd"); 165 if (major_num <= 0) { 166 pr_warn("nfhd: unable to get major number\n"); 167 return major_num; 168 } 169 170 for (i = NFHD_DEV_OFFSET; i < 24; i++) { 171 if (nfhd_get_capacity(i, 0, &blocks, &bsize)) 172 continue; 173 nfhd_init_one(i, blocks, bsize); 174 } 175 176 return 0; 177 } 178 179 static void __exit nfhd_exit(void) 180 { 181 struct nfhd_device *dev, *next; 182 183 list_for_each_entry_safe(dev, next, &nfhd_list, list) { 184 list_del(&dev->list); 185 del_gendisk(dev->disk); 186 put_disk(dev->disk); 187 blk_cleanup_queue(dev->queue); 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