1 files changed, 386 insertions, 0 deletions

diff --git a/kernel/drivers/nvdimm/blk.c b/kernel/drivers/nvdimm/blk.c
new file mode 100644
index 000000000..91a336ea8
--- /dev/null
+++ b/kernel/drivers/nvdimm/blk.c
@@ -0,0 +1,386 @@
+/*
+ * 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;
+	u32 sector_size;
+	u32 internal_lbasize;
+};
+
+static int nd_blk_major;
+
+static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
+{
+	return blk_dev->nsblk->lbasize - blk_dev->sector_size;
+}
+
+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;
+}
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
+				struct bio_integrity_payload *bip, u64 lba,
+				int rw)
+{
+	unsigned int len = nd_blk_meta_size(blk_dev);
+	resource_size_t	dev_offset, ns_offset;
+	struct nd_namespace_blk *nsblk;
+	struct nd_blk_region *ndbr;
+	int err = 0;
+
+	nsblk = blk_dev->nsblk;
+	ndbr = blk_dev->ndbr;
+	ns_offset = lba * blk_dev->internal_lbasize + blk_dev->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_blk_device *blk_dev,
+				struct bio_integrity_payload *bip, u64 lba,
+				int rw)
+{
+	return 0;
+}
+#endif
+
+static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
+			struct bio_integrity_payload *bip, struct page *page,
+			unsigned int len, unsigned int off, int rw,
+			sector_t sector)
+{
+	struct nd_blk_region *ndbr = blk_dev->ndbr;
+	resource_size_t	dev_offset, ns_offset;
+	int err = 0;
+	void *iobuf;
+	u64 lba;
+
+	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, blk_dev->sector_size) : len;
+
+		lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
+		ns_offset = lba * blk_dev->internal_lbasize;
+		dev_offset = to_dev_offset(blk_dev->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(blk_dev, bip, lba, rw);
+			if (err)
+				return err;
+		}
+		len -= cur_len;
+		off += cur_len;
+		sector += blk_dev->sector_size >> SECTOR_SHIFT;
+	}
+
+	return err;
+}
+
+static blk_qc_t 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 bio_integrity_payload *bip;
+	struct nd_blk_device *blk_dev;
+	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);
+	blk_dev = disk->private_data;
+	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 = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
+					bvec.bv_offset, rw, iter.bi_sector);
+		if (err) {
+			dev_info(&blk_dev->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 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,
+	.revalidate_disk = nvdimm_revalidate_disk,
+};
+
+static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
+		struct nd_blk_device *blk_dev)
+{
+	resource_size_t available_disk_size;
+	struct gendisk *disk;
+	u64 internal_nlba;
+
+	internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
+	available_disk_size = internal_nlba * blk_dev->sector_size;
+
+	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, blk_dev->sector_size);
+	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, 0);
+	add_disk(disk);
+
+	if (nd_blk_meta_size(blk_dev)) {
+		int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
+
+		if (rc) {
+			del_gendisk(disk);
+			put_disk(disk);
+			blk_cleanup_queue(blk_dev->queue);
+			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;
+	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;
+
+	nsblk = to_nd_namespace_blk(&ndns->dev);
+	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);
+	blk_dev->internal_lbasize = roundup(nsblk->lbasize,
+						INT_LBASIZE_ALIGNMENT);
+	blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
+	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);