Merge tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm

Pull libnvdimm subsystem from Dan Williams:
 "The libnvdimm sub-system introduces, in addition to the
  libnvdimm-core, 4 drivers / enabling modules:

  NFIT:
    Instantiates an "nvdimm bus" with the core and registers memory
    devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware
    Interface table).

    After registering NVDIMMs the NFIT driver then registers "region"
    devices.  A libnvdimm-region defines an access mode and the
    boundaries of persistent memory media.  A region may span multiple
    NVDIMMs that are interleaved by the hardware memory controller.  In
    turn, a libnvdimm-region can be carved into a "namespace" device and
    bound to the PMEM or BLK driver which will attach a Linux block
    device (disk) interface to the memory.

  PMEM:
    Initially merged in v4.1 this driver for contiguous spans of
    persistent memory address ranges is re-worked to drive
    PMEM-namespaces emitted by the libnvdimm-core.

    In this update the PMEM driver, on x86, gains the ability to assert
    that writes to persistent memory have been flushed all the way
    through the caches and buffers in the platform to persistent media.
    See memcpy_to_pmem() and wmb_pmem().

  BLK:
    This new driver enables access to persistent memory media through
    "Block Data Windows" as defined by the NFIT.  The primary difference
    of this driver to PMEM is that only a small window of persistent
    memory is mapped into system address space at any given point in
    time.

    Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access
    different portions of the media.  BLK-mode, by definition, does not
    support DAX.

  BTT:
    This is a library, optionally consumed by either PMEM or BLK, that
    converts a byte-accessible namespace into a disk with atomic sector
    update semantics (prevents sector tearing on crash or power loss).

    The sinister aspect of sector tearing is that most applications do
    not know they have a atomic sector dependency.  At least today's
    disk's rarely ever tear sectors and if they do one almost certainly
    gets a CRC error on access.  NVDIMMs will always tear and always
    silently.  Until an application is audited to be robust in the
    presence of sector-tearing the usage of BTT is recommended.

  Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
  Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
  Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
  Wysocki, and Bob Moore"

* tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits)
  arch, x86: pmem api for ensuring durability of persistent memory updates
  libnvdimm: Add sysfs numa_node to NVDIMM devices
  libnvdimm: Set numa_node to NVDIMM devices
  acpi: Add acpi_map_pxm_to_online_node()
  libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only
  pmem: flag pmem block devices as non-rotational
  libnvdimm: enable iostat
  pmem: make_request cleanups
  libnvdimm, pmem: fix up max_hw_sectors
  libnvdimm, blk: add support for blk integrity
  libnvdimm, btt: add support for blk integrity
  fs/block_dev.c: skip rw_page if bdev has integrity
  libnvdimm: Non-Volatile Devices
  tools/testing/nvdimm: libnvdimm unit test infrastructure
  libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory
  nd_btt: atomic sector updates
  libnvdimm: infrastructure for btt devices
  libnvdimm: write blk label set
  libnvdimm: write pmem label set
  libnvdimm: blk labels and namespace instantiation
  ...

1 files changed, 384 insertions, 0 deletions

diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
new file mode 100644
index 000000000000..4f97b248c236
--- /dev/null
+++ b/drivers/nvdimm/blk.c
@@ -0,0 +1,384 @@
+/*
+ * 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 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 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)) {
+		err = -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);
+			break;
+		}
+	}
+	if (do_acct)
+		nd_iostat_end(bio, start);
+
+ 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,
+	.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);