linux/drivers/nvdimm/blk.c

365 lines
9.0 KiB
C

/*
* 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"
static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
{
return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
}
static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
{
return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
}
static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
{
return nsblk->lbasize - nsblk_meta_size(nsblk);
}
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 struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
{
struct nd_region *nd_region;
struct device *parent;
parent = nsblk->common.dev.parent;
nd_region = container_of(parent, struct nd_region, dev);
return container_of(nd_region, struct nd_blk_region, nd_region);
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
struct bio_integrity_payload *bip, u64 lba, int rw)
{
struct nd_blk_region *ndbr = to_ndbr(nsblk);
unsigned int len = nsblk_meta_size(nsblk);
resource_size_t dev_offset, ns_offset;
u32 internal_lbasize, sector_size;
int err = 0;
internal_lbasize = nsblk_internal_lbasize(nsblk);
sector_size = nsblk_sector_size(nsblk);
ns_offset = lba * internal_lbasize + sector_size;
dev_offset = to_dev_offset(nsblk, ns_offset, len);
if (dev_offset == SIZE_MAX)
return -EIO;
while (len) {
unsigned int cur_len;
struct bio_vec bv;
void *iobuf;
bv = bvec_iter_bvec(bip->bip_vec, bip->bip_iter);
/*
* The 'bv' obtained from bvec_iter_bvec has its .bv_len and
* .bv_offset already adjusted for iter->bi_bvec_done, and we
* can use those directly
*/
cur_len = min(len, bv.bv_len);
iobuf = kmap_atomic(bv.bv_page);
err = ndbr->do_io(ndbr, dev_offset, iobuf + bv.bv_offset,
cur_len, rw);
kunmap_atomic(iobuf);
if (err)
return err;
len -= cur_len;
dev_offset += cur_len;
bvec_iter_advance(bip->bip_vec, &bip->bip_iter, cur_len);
}
return err;
}
#else /* CONFIG_BLK_DEV_INTEGRITY */
static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
struct bio_integrity_payload *bip, u64 lba, int rw)
{
return 0;
}
#endif
static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
struct bio_integrity_payload *bip, struct page *page,
unsigned int len, unsigned int off, int rw, sector_t sector)
{
struct nd_blk_region *ndbr = to_ndbr(nsblk);
resource_size_t dev_offset, ns_offset;
u32 internal_lbasize, sector_size;
int err = 0;
void *iobuf;
u64 lba;
internal_lbasize = nsblk_internal_lbasize(nsblk);
sector_size = nsblk_sector_size(nsblk);
while (len) {
unsigned int cur_len;
/*
* If we don't have an integrity payload, we don't have to
* split the bvec into sectors, as this would cause unnecessary
* Block Window setup/move steps. the do_io routine is capable
* of handling len <= PAGE_SIZE.
*/
cur_len = bip ? min(len, sector_size) : len;
lba = div_u64(sector << SECTOR_SHIFT, sector_size);
ns_offset = lba * internal_lbasize;
dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
if (dev_offset == SIZE_MAX)
return -EIO;
iobuf = kmap_atomic(page);
err = ndbr->do_io(ndbr, dev_offset, iobuf + off, cur_len, rw);
kunmap_atomic(iobuf);
if (err)
return err;
if (bip) {
err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
if (err)
return err;
}
len -= cur_len;
off += cur_len;
sector += sector_size >> SECTOR_SHIFT;
}
return err;
}
static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
{
struct bio_integrity_payload *bip;
struct nd_namespace_blk *nsblk;
struct bvec_iter iter;
unsigned long start;
struct bio_vec bvec;
int err = 0, rw;
bool do_acct;
/*
* bio_integrity_enabled also checks if the bio already has an
* integrity payload attached. If it does, we *don't* do a
* bio_integrity_prep here - the payload has been generated by
* another kernel subsystem, and we just pass it through.
*/
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
bio->bi_error = -EIO;
goto out;
}
bip = bio_integrity(bio);
nsblk = q->queuedata;
rw = bio_data_dir(bio);
do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
unsigned int len = bvec.bv_len;
BUG_ON(len > PAGE_SIZE);
err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
bvec.bv_offset, rw, iter.bi_sector);
if (err) {
dev_dbg(&nsblk->common.dev,
"io error in %s sector %lld, len %d,\n",
(rw == READ) ? "READ" : "WRITE",
(unsigned long long) iter.bi_sector, len);
bio->bi_error = err;
break;
}
}
if (do_acct)
nd_iostat_end(bio, start);
out:
bio_endio(bio);
return BLK_QC_T_NONE;
}
static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
resource_size_t offset, void *iobuf, size_t n, int rw)
{
struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
struct nd_blk_region *ndbr = to_ndbr(nsblk);
resource_size_t dev_offset;
dev_offset = to_dev_offset(nsblk, offset, n);
if (unlikely(offset + n > nsblk->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,
.revalidate_disk = nvdimm_revalidate_disk,
};
static void nd_blk_release_queue(void *q)
{
blk_cleanup_queue(q);
}
static void nd_blk_release_disk(void *disk)
{
del_gendisk(disk);
put_disk(disk);
}
static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
{
struct device *dev = &nsblk->common.dev;
resource_size_t available_disk_size;
struct request_queue *q;
struct gendisk *disk;
u64 internal_nlba;
internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
q = blk_alloc_queue(GFP_KERNEL);
if (!q)
return -ENOMEM;
if (devm_add_action(dev, nd_blk_release_queue, q)) {
blk_cleanup_queue(q);
return -ENOMEM;
}
blk_queue_make_request(q, nd_blk_make_request);
blk_queue_max_hw_sectors(q, UINT_MAX);
blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
q->queuedata = nsblk;
disk = alloc_disk(0);
if (!disk)
return -ENOMEM;
if (devm_add_action(dev, nd_blk_release_disk, disk)) {
put_disk(disk);
return -ENOMEM;
}
disk->driverfs_dev = dev;
disk->first_minor = 0;
disk->fops = &nd_blk_fops;
disk->queue = q;
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
set_capacity(disk, 0);
add_disk(disk);
if (nsblk_meta_size(nsblk)) {
int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
if (rc)
return rc;
}
set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
revalidate_disk(disk);
return 0;
}
static int nd_blk_probe(struct device *dev)
{
struct nd_namespace_common *ndns;
struct nd_namespace_blk *nsblk;
ndns = nvdimm_namespace_common_probe(dev);
if (IS_ERR(ndns))
return PTR_ERR(ndns);
nsblk = to_nd_namespace_blk(&ndns->dev);
nsblk->size = nvdimm_namespace_capacity(ndns);
dev_set_drvdata(dev, nsblk);
ndns->rw_bytes = nsblk_rw_bytes;
if (is_nd_btt(dev))
return nvdimm_namespace_attach_btt(ndns);
else if (nd_btt_probe(dev, ndns) == 0) {
/* we'll come back as btt-blk */
return -ENXIO;
} else
return nsblk_attach_disk(nsblk);
}
static int nd_blk_remove(struct device *dev)
{
if (is_nd_btt(dev))
nvdimm_namespace_detach_btt(to_nd_btt(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)
{
return nd_driver_register(&nd_blk_driver);
}
static void __exit nd_blk_exit(void)
{
driver_unregister(&nd_blk_driver.drv);
}
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);