LXR linux/arch/m68k/emu/nfblock.c

   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
  23static long nfhd_id;
  24
  25enum {
  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
  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 request_queue *queue;
  59        struct gendisk *disk;
  60};
  61
  62static void nfhd_make_request(struct request_queue *queue, struct bio *bio)
  63{
  64        struct nfhd_device *dev = queue->queuedata;
  65        struct bio_vec *bvec;
  66        int i, dir, len, shift;
  67        sector_t sec = bio->bi_sector;
  68
  69        dir = bio_data_dir(bio);
  70        shift = dev->bshift;
  71        bio_for_each_segment(bvec, bio, i) {
  72                len = bvec->bv_len;
  73                len >>= 9;
  74                nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
  75                                bvec_to_phys(bvec));
  76                sec += len;
  77        }
  78        bio_endio(bio, 0);
  79}
  80
  81static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
  82{
  83        struct nfhd_device *dev = bdev->bd_disk->private_data;
  84
  85        geo->cylinders = dev->blocks >> (6 - dev->bshift);
  86        geo->heads = 4;
  87        geo->sectors = 16;
  88
  89        return 0;
  90}
  91
  92static const struct block_device_operations nfhd_ops = {
  93        .owner  = THIS_MODULE,
  94        .getgeo = nfhd_getgeo,
  95};
  96
  97static 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
 102        pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
 103                blocks, bsize);
 104
 105        if (bsize < 512 || (bsize & (bsize - 1))) {
 106                pr_warn("nfhd%u: invalid block size\n", dev_id);
 107                return -EINVAL;
 108        }
 109
 110        dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
 111        if (!dev)
 112                goto out;
 113
 114        dev->id = id;
 115        dev->blocks = blocks;
 116        dev->bsize = bsize;
 117        dev->bshift = ffs(bsize) - 10;
 118
 119        dev->queue = blk_alloc_queue(GFP_KERNEL);
 120        if (dev->queue == NULL)
 121                goto free_dev;
 122
 123        dev->queue->queuedata = dev;
 124        blk_queue_make_request(dev->queue, nfhd_make_request);
 125        blk_queue_logical_block_size(dev->queue, bsize);
 126
 127        dev->disk = alloc_disk(16);
 128        if (!dev->disk)
 129                goto free_queue;
 130
 131        dev->disk->major = major_num;
 132        dev->disk->first_minor = dev_id * 16;
 133        dev->disk->fops = &nfhd_ops;
 134        dev->disk->private_data = dev;
 135        sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
 136        set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
 137        dev->disk->queue = dev->queue;
 138
 139        add_disk(dev->disk);
 140
 141        list_add_tail(&dev->list, &nfhd_list);
 142
 143        return 0;
 144
 145free_queue:
 146        blk_cleanup_queue(dev->queue);
 147free_dev:
 148        kfree(dev);
 149out:
 150        return -ENOMEM;
 151}
 152
 153static int __init nfhd_init(void)
 154{
 155        u32 blocks, bsize;
 156        int i;
 157
 158        nfhd_id = nf_get_id("XHDI");
 159        if (!nfhd_id)
 160                return -ENODEV;
 161
 162        major_num = register_blkdev(major_num, "nfhd");
 163        if (major_num <= 0) {
 164                pr_warn("nfhd: unable to get major number\n");
 165                return major_num;
 166        }
 167
 168        for (i = NFHD_DEV_OFFSET; i < 24; i++) {
 169                if (nfhd_get_capacity(i, 0, &blocks, &bsize))
 170                        continue;
 171                nfhd_init_one(i, blocks, bsize);
 172        }
 173
 174        return 0;
 175}
 176
 177static void __exit nfhd_exit(void)
 178{
 179        struct nfhd_device *dev, *next;
 180
 181        list_for_each_entry_safe(dev, next, &nfhd_list, list) {
 182                list_del(&dev->list);
 183                del_gendisk(dev->disk);
 184                put_disk(dev->disk);
 185                blk_cleanup_queue(dev->queue);
 186                kfree(dev);
 187        }
 188        unregister_blkdev(major_num, "nfhd");
 189}
 190
 191module_init(nfhd_init);
 192module_exit(nfhd_exit);
 193
 194MODULE_LICENSE("GPL");
 195