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/*
* NVDIMM Block Window Driver
* Copyright (c) 2014, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/nd.h>
#include <linux/sizes.h>
#include "nd.h"
struct nd_blk_device {
struct request_queue *queue;
struct gendisk *disk;
struct nd_namespace_blk *nsblk;
struct nd_blk_region *ndbr;
size_t disk_size;
};
static int nd_blk_major;
static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
resource_size_t ns_offset, unsigned int len)
{
int i;
for (i = 0; i < nsblk->num_resources; i++) {
if (ns_offset < resource_size(nsblk->res[i])) {
if (ns_offset + len > resource_size(nsblk->res[i])) {
dev_WARN_ONCE(&nsblk->common.dev, 1,
"illegal request\n");
return SIZE_MAX;
}
return nsblk->res[i]->start + ns_offset;
}
ns_offset -= resource_size(nsblk->res[i]);
}
dev_WARN_ONCE(&nsblk->common.dev, 1, "request out of range\n");
return SIZE_MAX;
}
static void nd_blk_make_request(struct request_queue *q, struct bio *bio)
{
struct block_device *bdev = bio->bi_bdev;
struct gendisk *disk = bdev->bd_disk;
struct nd_namespace_blk *nsblk;
struct nd_blk_device *blk_dev;
struct nd_blk_region *ndbr;
struct bvec_iter iter;
struct bio_vec bvec;
int err = 0, rw;
blk_dev = disk->private_data;
nsblk = blk_dev->nsblk;
ndbr = blk_dev->ndbr;
rw = bio_data_dir(bio);
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;
resource_size_t dev_offset;
void *iobuf;
BUG_ON(len > PAGE_SIZE);
dev_offset = to_dev_offset(nsblk,
iter.bi_sector << SECTOR_SHIFT, len);
if (dev_offset == SIZE_MAX) {
err = -EIO;
goto out;
}
iobuf = kmap_atomic(bvec.bv_page);
err = ndbr->do_io(ndbr, dev_offset, iobuf + bvec.bv_offset,
len, rw);
kunmap_atomic(iobuf);
if (err)
goto out;
}
out:
bio_endio(bio, err);
}
static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
resource_size_t offset, void *iobuf, size_t n, int rw)
{
struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
struct nd_namespace_blk *nsblk = blk_dev->nsblk;
struct nd_blk_region *ndbr = blk_dev->ndbr;
resource_size_t dev_offset;
dev_offset = to_dev_offset(nsblk, offset, n);
if (unlikely(offset + n > blk_dev->disk_size)) {
dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
return -EFAULT;
}
if (dev_offset == SIZE_MAX)
return -EIO;
return ndbr->do_io(ndbr, dev_offset, iobuf, n, rw);
}
static const struct block_device_operations nd_blk_fops = {
.owner = THIS_MODULE,
};
static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
struct nd_blk_device *blk_dev)
{
struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
struct gendisk *disk;
blk_dev->queue = blk_alloc_queue(GFP_KERNEL);
if (!blk_dev->queue)
return -ENOMEM;
blk_queue_make_request(blk_dev->queue, nd_blk_make_request);
blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX);
blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY);
blk_queue_logical_block_size(blk_dev->queue, nsblk->lbasize);
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue);
disk = blk_dev->disk = alloc_disk(0);
if (!disk) {
blk_cleanup_queue(blk_dev->queue);
return -ENOMEM;
}
disk->driverfs_dev = &ndns->dev;
disk->major = nd_blk_major;
disk->first_minor = 0;
disk->fops = &nd_blk_fops;
disk->private_data = blk_dev;
disk->queue = blk_dev->queue;
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
set_capacity(disk, blk_dev->disk_size >> SECTOR_SHIFT);
add_disk(disk);
return 0;
}
static int nd_blk_probe(struct device *dev)
{
struct nd_namespace_common *ndns;
struct nd_blk_device *blk_dev;
int rc;
ndns = nvdimm_namespace_common_probe(dev);
if (IS_ERR(ndns))
return PTR_ERR(ndns);
blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL);
if (!blk_dev)
return -ENOMEM;
blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
blk_dev->ndbr = to_nd_blk_region(dev->parent);
blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
dev_set_drvdata(dev, blk_dev);
ndns->rw_bytes = nd_blk_rw_bytes;
if (is_nd_btt(dev))
rc = nvdimm_namespace_attach_btt(ndns);
else if (nd_btt_probe(ndns, blk_dev) == 0) {
/* we'll come back as btt-blk */
rc = -ENXIO;
} else
rc = nd_blk_attach_disk(ndns, blk_dev);
if (rc)
kfree(blk_dev);
return rc;
}
static void nd_blk_detach_disk(struct nd_blk_device *blk_dev)
{
del_gendisk(blk_dev->disk);
put_disk(blk_dev->disk);
blk_cleanup_queue(blk_dev->queue);
}
static int nd_blk_remove(struct device *dev)
{
struct nd_blk_device *blk_dev = dev_get_drvdata(dev);
if (is_nd_btt(dev))
nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
else
nd_blk_detach_disk(blk_dev);
kfree(blk_dev);
return 0;
}
static struct nd_device_driver nd_blk_driver = {
.probe = nd_blk_probe,
.remove = nd_blk_remove,
.drv = {
.name = "nd_blk",
},
.type = ND_DRIVER_NAMESPACE_BLK,
};
static int __init nd_blk_init(void)
{
int rc;
rc = register_blkdev(0, "nd_blk");
if (rc < 0)
return rc;
nd_blk_major = rc;
rc = nd_driver_register(&nd_blk_driver);
if (rc < 0)
unregister_blkdev(nd_blk_major, "nd_blk");
return rc;
}
static void __exit nd_blk_exit(void)
{
driver_unregister(&nd_blk_driver.drv);
unregister_blkdev(nd_blk_major, "nd_blk");
}
MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_BLK);
module_init(nd_blk_init);
module_exit(nd_blk_exit);
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