diff options
Diffstat (limited to 'drivers/nvdimm/blk.c')
| -rw-r--r-- | drivers/nvdimm/blk.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c new file mode 100644 index 000000000000..9ac0c266c15c --- /dev/null +++ b/drivers/nvdimm/blk.c @@ -0,0 +1,245 @@ +/* + * 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); |
