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, 301 insertions, 0 deletions

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
new file mode 100644
index 000000000000..ade9eb917a4d
--- /dev/null
+++ b/drivers/nvdimm/pmem.c
@@ -0,0 +1,301 @@
+/*
+ * Persistent Memory Driver
+ *
+ * Copyright (c) 2014-2015, Intel Corporation.
+ * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
+ * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
+ *
+ * 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 <asm/cacheflush.h>
+#include <linux/blkdev.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/pmem.h>
+#include <linux/nd.h>
+#include "nd.h"
+
+struct pmem_device {
+	struct request_queue	*pmem_queue;
+	struct gendisk		*pmem_disk;
+
+	/* One contiguous memory region per device */
+	phys_addr_t		phys_addr;
+	void __pmem		*virt_addr;
+	size_t			size;
+};
+
+static int pmem_major;
+
+static void pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+			unsigned int len, unsigned int off, int rw,
+			sector_t sector)
+{
+	void *mem = kmap_atomic(page);
+	size_t pmem_off = sector << 9;
+	void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
+
+	if (rw == READ) {
+		memcpy_from_pmem(mem + off, pmem_addr, len);
+		flush_dcache_page(page);
+	} else {
+		flush_dcache_page(page);
+		memcpy_to_pmem(pmem_addr, mem + off, len);
+	}
+
+	kunmap_atomic(mem);
+}
+
+static void pmem_make_request(struct request_queue *q, struct bio *bio)
+{
+	bool do_acct;
+	unsigned long start;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	struct block_device *bdev = bio->bi_bdev;
+	struct pmem_device *pmem = bdev->bd_disk->private_data;
+
+	do_acct = nd_iostat_start(bio, &start);
+	bio_for_each_segment(bvec, bio, iter)
+		pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset,
+				bio_data_dir(bio), iter.bi_sector);
+	if (do_acct)
+		nd_iostat_end(bio, start);
+
+	if (bio_data_dir(bio))
+		wmb_pmem();
+
+	bio_endio(bio, 0);
+}
+
+static int pmem_rw_page(struct block_device *bdev, sector_t sector,
+		       struct page *page, int rw)
+{
+	struct pmem_device *pmem = bdev->bd_disk->private_data;
+
+	pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector);
+	page_endio(page, rw & WRITE, 0);
+
+	return 0;
+}
+
+static long pmem_direct_access(struct block_device *bdev, sector_t sector,
+			      void **kaddr, unsigned long *pfn, long size)
+{
+	struct pmem_device *pmem = bdev->bd_disk->private_data;
+	size_t offset = sector << 9;
+
+	if (!pmem)
+		return -ENODEV;
+
+	/* FIXME convert DAX to comprehend that this mapping has a lifetime */
+	*kaddr = (void __force *) pmem->virt_addr + offset;
+	*pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
+
+	return pmem->size - offset;
+}
+
+static const struct block_device_operations pmem_fops = {
+	.owner =		THIS_MODULE,
+	.rw_page =		pmem_rw_page,
+	.direct_access =	pmem_direct_access,
+	.revalidate_disk =	nvdimm_revalidate_disk,
+};
+
+static struct pmem_device *pmem_alloc(struct device *dev,
+		struct resource *res, int id)
+{
+	struct pmem_device *pmem;
+
+	pmem = kzalloc(sizeof(*pmem), GFP_KERNEL);
+	if (!pmem)
+		return ERR_PTR(-ENOMEM);
+
+	pmem->phys_addr = res->start;
+	pmem->size = resource_size(res);
+	if (!arch_has_pmem_api())
+		dev_warn(dev, "unable to guarantee persistence of writes\n");
+
+	if (!request_mem_region(pmem->phys_addr, pmem->size, dev_name(dev))) {
+		dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
+				&pmem->phys_addr, pmem->size);
+		kfree(pmem);
+		return ERR_PTR(-EBUSY);
+	}
+
+	pmem->virt_addr = memremap_pmem(pmem->phys_addr, pmem->size);
+	if (!pmem->virt_addr) {
+		release_mem_region(pmem->phys_addr, pmem->size);
+		kfree(pmem);
+		return ERR_PTR(-ENXIO);
+	}
+
+	return pmem;
+}
+
+static void pmem_detach_disk(struct pmem_device *pmem)
+{
+	del_gendisk(pmem->pmem_disk);
+	put_disk(pmem->pmem_disk);
+	blk_cleanup_queue(pmem->pmem_queue);
+}
+
+static int pmem_attach_disk(struct nd_namespace_common *ndns,
+		struct pmem_device *pmem)
+{
+	struct gendisk *disk;
+
+	pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL);
+	if (!pmem->pmem_queue)
+		return -ENOMEM;
+
+	blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
+	blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
+	blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
+	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
+
+	disk = alloc_disk(0);
+	if (!disk) {
+		blk_cleanup_queue(pmem->pmem_queue);
+		return -ENOMEM;
+	}
+
+	disk->major		= pmem_major;
+	disk->first_minor	= 0;
+	disk->fops		= &pmem_fops;
+	disk->private_data	= pmem;
+	disk->queue		= pmem->pmem_queue;
+	disk->flags		= GENHD_FL_EXT_DEVT;
+	nvdimm_namespace_disk_name(ndns, disk->disk_name);
+	disk->driverfs_dev = &ndns->dev;
+	set_capacity(disk, pmem->size >> 9);
+	pmem->pmem_disk = disk;
+
+	add_disk(disk);
+	revalidate_disk(disk);
+
+	return 0;
+}
+
+static int pmem_rw_bytes(struct nd_namespace_common *ndns,
+		resource_size_t offset, void *buf, size_t size, int rw)
+{
+	struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
+
+	if (unlikely(offset + size > pmem->size)) {
+		dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
+		return -EFAULT;
+	}
+
+	if (rw == READ)
+		memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
+	else {
+		memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
+		wmb_pmem();
+	}
+
+	return 0;
+}
+
+static void pmem_free(struct pmem_device *pmem)
+{
+	memunmap_pmem(pmem->virt_addr);
+	release_mem_region(pmem->phys_addr, pmem->size);
+	kfree(pmem);
+}
+
+static int nd_pmem_probe(struct device *dev)
+{
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct nd_namespace_common *ndns;
+	struct nd_namespace_io *nsio;
+	struct pmem_device *pmem;
+	int rc;
+
+	ndns = nvdimm_namespace_common_probe(dev);
+	if (IS_ERR(ndns))
+		return PTR_ERR(ndns);
+
+	nsio = to_nd_namespace_io(&ndns->dev);
+	pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
+	if (IS_ERR(pmem))
+		return PTR_ERR(pmem);
+
+	dev_set_drvdata(dev, pmem);
+	ndns->rw_bytes = pmem_rw_bytes;
+	if (is_nd_btt(dev))
+		rc = nvdimm_namespace_attach_btt(ndns);
+	else if (nd_btt_probe(ndns, pmem) == 0) {
+		/* we'll come back as btt-pmem */
+		rc = -ENXIO;
+	} else
+		rc = pmem_attach_disk(ndns, pmem);
+	if (rc)
+		pmem_free(pmem);
+	return rc;
+}
+
+static int nd_pmem_remove(struct device *dev)
+{
+	struct pmem_device *pmem = dev_get_drvdata(dev);
+
+	if (is_nd_btt(dev))
+		nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
+	else
+		pmem_detach_disk(pmem);
+	pmem_free(pmem);
+
+	return 0;
+}
+
+MODULE_ALIAS("pmem");
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
+MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
+static struct nd_device_driver nd_pmem_driver = {
+	.probe = nd_pmem_probe,
+	.remove = nd_pmem_remove,
+	.drv = {
+		.name = "nd_pmem",
+	},
+	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
+};
+
+static int __init pmem_init(void)
+{
+	int error;
+
+	pmem_major = register_blkdev(0, "pmem");
+	if (pmem_major < 0)
+		return pmem_major;
+
+	error = nd_driver_register(&nd_pmem_driver);
+	if (error) {
+		unregister_blkdev(pmem_major, "pmem");
+		return error;
+	}
+
+	return 0;
+}
+module_init(pmem_init);
+
+static void pmem_exit(void)
+{
+	driver_unregister(&nd_pmem_driver.drv);
+	unregister_blkdev(pmem_major, "pmem");
+}
+module_exit(pmem_exit);
+
+MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
+MODULE_LICENSE("GPL v2");