![Chengguang Xu](/assets/img/avatar_default.png)
When calling register_blkdev() with specified major device number, the return code is 0 on success. So it seems not correct direct assign return code to variable major_num in this case. Tested-by: Michael Schmitz <schmitzmic@gmail.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
201 lines
4.1 KiB
C
201 lines
4.1 KiB
C
/*
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* ARAnyM block device driver
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/genhd.h>
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#include <linux/blkdev.h>
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#include <linux/hdreg.h>
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#include <linux/slab.h>
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#include <asm/natfeat.h>
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static long nfhd_id;
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enum {
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/* emulation entry points */
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NFHD_READ_WRITE = 10,
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NFHD_GET_CAPACITY = 14,
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/* skip ACSI devices */
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NFHD_DEV_OFFSET = 8,
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};
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static inline s32 nfhd_read_write(u32 major, u32 minor, u32 rwflag, u32 recno,
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u32 count, u32 buf)
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{
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return nf_call(nfhd_id + NFHD_READ_WRITE, major, minor, rwflag, recno,
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count, buf);
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}
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static inline s32 nfhd_get_capacity(u32 major, u32 minor, u32 *blocks,
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u32 *blocksize)
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{
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return nf_call(nfhd_id + NFHD_GET_CAPACITY, major, minor,
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virt_to_phys(blocks), virt_to_phys(blocksize));
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}
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static LIST_HEAD(nfhd_list);
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static int major_num;
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module_param(major_num, int, 0);
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struct nfhd_device {
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struct list_head list;
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int id;
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u32 blocks, bsize;
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int bshift;
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struct request_queue *queue;
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struct gendisk *disk;
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};
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static blk_qc_t nfhd_make_request(struct request_queue *queue, struct bio *bio)
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{
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struct nfhd_device *dev = queue->queuedata;
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struct bio_vec bvec;
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struct bvec_iter iter;
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int dir, len, shift;
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sector_t sec = bio->bi_iter.bi_sector;
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dir = bio_data_dir(bio);
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shift = dev->bshift;
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bio_for_each_segment(bvec, bio, iter) {
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len = bvec.bv_len;
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len >>= 9;
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nfhd_read_write(dev->id, 0, dir, sec >> shift, len >> shift,
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page_to_phys(bvec.bv_page) + bvec.bv_offset);
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sec += len;
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}
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bio_endio(bio);
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return BLK_QC_T_NONE;
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}
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static int nfhd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
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{
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struct nfhd_device *dev = bdev->bd_disk->private_data;
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geo->cylinders = dev->blocks >> (6 - dev->bshift);
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geo->heads = 4;
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geo->sectors = 16;
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return 0;
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}
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static const struct block_device_operations nfhd_ops = {
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.owner = THIS_MODULE,
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.getgeo = nfhd_getgeo,
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};
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static int __init nfhd_init_one(int id, u32 blocks, u32 bsize)
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{
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struct nfhd_device *dev;
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int dev_id = id - NFHD_DEV_OFFSET;
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pr_info("nfhd%u: found device with %u blocks (%u bytes)\n", dev_id,
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blocks, bsize);
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if (bsize < 512 || (bsize & (bsize - 1))) {
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pr_warn("nfhd%u: invalid block size\n", dev_id);
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return -EINVAL;
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}
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dev = kmalloc(sizeof(struct nfhd_device), GFP_KERNEL);
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if (!dev)
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goto out;
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dev->id = id;
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dev->blocks = blocks;
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dev->bsize = bsize;
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dev->bshift = ffs(bsize) - 10;
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dev->queue = blk_alloc_queue(GFP_KERNEL);
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if (dev->queue == NULL)
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goto free_dev;
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dev->queue->queuedata = dev;
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blk_queue_make_request(dev->queue, nfhd_make_request);
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blk_queue_logical_block_size(dev->queue, bsize);
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dev->disk = alloc_disk(16);
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if (!dev->disk)
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goto free_queue;
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dev->disk->major = major_num;
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dev->disk->first_minor = dev_id * 16;
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dev->disk->fops = &nfhd_ops;
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dev->disk->private_data = dev;
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sprintf(dev->disk->disk_name, "nfhd%u", dev_id);
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set_capacity(dev->disk, (sector_t)blocks * (bsize / 512));
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dev->disk->queue = dev->queue;
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add_disk(dev->disk);
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list_add_tail(&dev->list, &nfhd_list);
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return 0;
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free_queue:
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blk_cleanup_queue(dev->queue);
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free_dev:
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kfree(dev);
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out:
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return -ENOMEM;
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}
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static int __init nfhd_init(void)
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{
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u32 blocks, bsize;
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int ret;
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int i;
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nfhd_id = nf_get_id("XHDI");
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if (!nfhd_id)
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return -ENODEV;
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ret = register_blkdev(major_num, "nfhd");
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if (ret < 0) {
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pr_warn("nfhd: unable to get major number\n");
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return ret;
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}
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if (!major_num)
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major_num = ret;
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for (i = NFHD_DEV_OFFSET; i < 24; i++) {
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if (nfhd_get_capacity(i, 0, &blocks, &bsize))
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continue;
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nfhd_init_one(i, blocks, bsize);
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}
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return 0;
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}
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static void __exit nfhd_exit(void)
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{
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struct nfhd_device *dev, *next;
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list_for_each_entry_safe(dev, next, &nfhd_list, list) {
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list_del(&dev->list);
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del_gendisk(dev->disk);
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put_disk(dev->disk);
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blk_cleanup_queue(dev->queue);
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kfree(dev);
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}
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unregister_blkdev(major_num, "nfhd");
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}
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module_init(nfhd_init);
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module_exit(nfhd_exit);
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MODULE_LICENSE("GPL");
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