Merge branch 'for-4.13/dax' into libnvdimm-for-next

18 files changed, 360 insertions, 56 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 1f6bc50..b75b734 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -20,7 +20,6 @@
 #include <linux/list.h>
 #include <linux/acpi.h>
 #include <linux/sort.h>
-#include <linux/pmem.h>
 #include <linux/io.h>
 #include <linux/nd.h>
 #include <asm/cacheflush.h>
@@ -1928,8 +1927,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
 		}
 
 		if (rw)
-			memcpy_to_pmem(mmio->addr.aperture + offset,
-					iobuf + copied, c);
+			memcpy_flushcache(mmio->addr.aperture + offset, iobuf + copied, c);
 		else {
 			if (nfit_blk->dimm_flags & NFIT_BLK_READ_FLUSH)
 				mmio_flush_range((void __force *)
@@ -2043,7 +2041,7 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	nfit_blk->bdw_offset = nfit_mem->bdw->offset;
 	mmio = &nfit_blk->mmio[BDW];
 	mmio->addr.base = devm_nvdimm_memremap(dev, nfit_mem->spa_bdw->address,
-                        nfit_mem->spa_bdw->length, ARCH_MEMREMAP_PMEM);
+                        nfit_mem->spa_bdw->length, nd_blk_memremap_flags(ndbr));
 	if (!mmio->addr.base) {
 		dev_dbg(dev, "%s: %s failed to map bdw\n", __func__,
 				nvdimm_name(nvdimm));
@@ -2320,6 +2318,13 @@ static bool nfit_spa_is_virtual(struct acpi_nfit_system_address *spa)
 		nfit_spa_type(spa) == NFIT_SPA_PCD);
 }
 
+static bool nfit_spa_is_volatile(struct acpi_nfit_system_address *spa)
+{
+	return (nfit_spa_type(spa) == NFIT_SPA_VDISK ||
+		nfit_spa_type(spa) == NFIT_SPA_VCD   ||
+		nfit_spa_type(spa) == NFIT_SPA_VOLATILE);
+}
+
 static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 		struct nfit_spa *nfit_spa)
 {
@@ -2394,7 +2399,7 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 				ndr_desc);
 		if (!nfit_spa->nd_region)
 			rc = -ENOMEM;
-	} else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE) {
+	} else if (nfit_spa_is_volatile(spa)) {
 		nfit_spa->nd_region = nvdimm_volatile_region_create(nvdimm_bus,
 				ndr_desc);
 		if (!nfit_spa->nd_region)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 57b574f..f2a7ac3 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -22,6 +22,7 @@
 #ifdef CONFIG_BLK_DEV_RAM_DAX
 #include <linux/pfn_t.h>
 #include <linux/dax.h>
+#include <linux/uio.h>
 #endif
 
 #include <linux/uaccess.h>
@@ -354,8 +355,15 @@ static long brd_dax_direct_access(struct dax_device *dax_dev,
 	return __brd_direct_access(brd, pgoff, nr_pages, kaddr, pfn);
 }
 
+static size_t brd_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter(addr, bytes, i);
+}
+
 static const struct dax_operations brd_dax_ops = {
 	.direct_access = brd_dax_direct_access,
+	.copy_from_iter = brd_dax_copy_from_iter,
 };
 #endif
 
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 6ed32aa..4827251 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -18,6 +18,7 @@
 #include <linux/cdev.h>
 #include <linux/hash.h>
 #include <linux/slab.h>
+#include <linux/uio.h>
 #include <linux/dax.h>
 #include <linux/fs.h>
 
@@ -115,13 +116,20 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 EXPORT_SYMBOL_GPL(__bdev_dax_supported);
 #endif
 
+enum dax_device_flags {
+	/* !alive + rcu grace period == no new operations / mappings */
+	DAXDEV_ALIVE,
+	/* gate whether dax_flush() calls the low level flush routine */
+	DAXDEV_WRITE_CACHE,
+};
+
 /**
  * struct dax_device - anchor object for dax services
  * @inode: core vfs
  * @cdev: optional character interface for "device dax"
  * @host: optional name for lookups where the device path is not available
  * @private: dax driver private data
- * @alive: !alive + rcu grace period == no new operations / mappings
+ * @flags: state and boolean properties
  */
 struct dax_device {
 	struct hlist_node list;
@@ -129,10 +137,75 @@ struct dax_device {
 	struct cdev cdev;
 	const char *host;
 	void *private;
-	bool alive;
+	unsigned long flags;
 	const struct dax_operations *ops;
 };
 
+static ssize_t write_cache_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dax_device *dax_dev = dax_get_by_host(dev_name(dev));
+	ssize_t rc;
+
+	WARN_ON_ONCE(!dax_dev);
+	if (!dax_dev)
+		return -ENXIO;
+
+	rc = sprintf(buf, "%d\n", !!test_bit(DAXDEV_WRITE_CACHE,
+				&dax_dev->flags));
+	put_dax(dax_dev);
+	return rc;
+}
+
+static ssize_t write_cache_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	bool write_cache;
+	int rc = strtobool(buf, &write_cache);
+	struct dax_device *dax_dev = dax_get_by_host(dev_name(dev));
+
+	WARN_ON_ONCE(!dax_dev);
+	if (!dax_dev)
+		return -ENXIO;
+
+	if (rc)
+		len = rc;
+	else if (write_cache)
+		set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
+	else
+		clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
+
+	put_dax(dax_dev);
+	return len;
+}
+static DEVICE_ATTR_RW(write_cache);
+
+static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+	struct device *dev = container_of(kobj, typeof(*dev), kobj);
+	struct dax_device *dax_dev = dax_get_by_host(dev_name(dev));
+
+	WARN_ON_ONCE(!dax_dev);
+	if (!dax_dev)
+		return 0;
+
+	if (a == &dev_attr_write_cache.attr && !dax_dev->ops->flush)
+		return 0;
+	return a->mode;
+}
+
+static struct attribute *dax_attributes[] = {
+	&dev_attr_write_cache.attr,
+	NULL,
+};
+
+struct attribute_group dax_attribute_group = {
+	.name = "dax",
+	.attrs = dax_attributes,
+	.is_visible = dax_visible,
+};
+EXPORT_SYMBOL_GPL(dax_attribute_group);
+
 /**
  * dax_direct_access() - translate a device pgoff to an absolute pfn
  * @dax_dev: a dax_device instance representing the logical memory range
@@ -172,10 +245,43 @@ long dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, long nr_pages,
 }
 EXPORT_SYMBOL_GPL(dax_direct_access);
 
+size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+		size_t bytes, struct iov_iter *i)
+{
+	if (!dax_alive(dax_dev))
+		return 0;
+
+	return dax_dev->ops->copy_from_iter(dax_dev, pgoff, addr, bytes, i);
+}
+EXPORT_SYMBOL_GPL(dax_copy_from_iter);
+
+void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+		size_t size)
+{
+	if (!dax_alive(dax_dev))
+		return;
+
+	if (!test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags))
+		return;
+
+	if (dax_dev->ops->flush)
+		dax_dev->ops->flush(dax_dev, pgoff, addr, size);
+}
+EXPORT_SYMBOL_GPL(dax_flush);
+
+void dax_write_cache(struct dax_device *dax_dev, bool wc)
+{
+	if (wc)
+		set_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
+	else
+		clear_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags);
+}
+EXPORT_SYMBOL_GPL(dax_write_cache);
+
 bool dax_alive(struct dax_device *dax_dev)
 {
 	lockdep_assert_held(&dax_srcu);
-	return dax_dev->alive;
+	return test_bit(DAXDEV_ALIVE, &dax_dev->flags);
 }
 EXPORT_SYMBOL_GPL(dax_alive);
 
@@ -195,7 +301,7 @@ void kill_dax(struct dax_device *dax_dev)
 	if (!dax_dev)
 		return;
 
-	dax_dev->alive = false;
+	clear_bit(DAXDEV_ALIVE, &dax_dev->flags);
 
 	synchronize_srcu(&dax_srcu);
 
@@ -235,7 +341,7 @@ static void dax_destroy_inode(struct inode *inode)
 {
 	struct dax_device *dax_dev = to_dax_dev(inode);
 
-	WARN_ONCE(dax_dev->alive,
+	WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags),
 			"kill_dax() must be called before final iput()\n");
 	call_rcu(&inode->i_rcu, dax_i_callback);
 }
@@ -287,7 +393,7 @@ static struct dax_device *dax_dev_get(dev_t devt)
 
 	dax_dev = to_dax_dev(inode);
 	if (inode->i_state & I_NEW) {
-		dax_dev->alive = true;
+		set_bit(DAXDEV_ALIVE, &dax_dev->flags);
 		inode->i_cdev = &dax_dev->cdev;
 		inode->i_mode = S_IFCHR;
 		inode->i_flags = S_DAX;
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 7d42a9d..25e6619 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -159,6 +159,34 @@ static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
+static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	struct linear_c *lc = ti->private;
+	struct block_device *bdev = lc->dev->bdev;
+	struct dax_device *dax_dev = lc->dev->dax_dev;
+	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+
+	dev_sector = linear_map_sector(ti, sector);
+	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
+		return 0;
+	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
+}
+
+static void linear_dax_flush(struct dm_target *ti, pgoff_t pgoff, void *addr,
+		size_t size)
+{
+	struct linear_c *lc = ti->private;
+	struct block_device *bdev = lc->dev->bdev;
+	struct dax_device *dax_dev = lc->dev->dax_dev;
+	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+
+	dev_sector = linear_map_sector(ti, sector);
+	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(size, PAGE_SIZE), &pgoff))
+		return;
+	dax_flush(dax_dev, pgoff, addr, size);
+}
+
 static struct target_type linear_target = {
 	.name   = "linear",
 	.version = {1, 3, 0},
@@ -171,6 +199,8 @@ static struct target_type linear_target = {
 	.prepare_ioctl = linear_prepare_ioctl,
 	.iterate_devices = linear_iterate_devices,
 	.direct_access = linear_dax_direct_access,
+	.dax_copy_from_iter = linear_dax_copy_from_iter,
+	.dax_flush = linear_dax_flush,
 };
 
 int __init dm_linear_init(void)
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 7515248..8e73517 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -332,6 +332,44 @@ static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 	return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
 }
 
+static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+	struct stripe_c *sc = ti->private;
+	struct dax_device *dax_dev;
+	struct block_device *bdev;
+	uint32_t stripe;
+
+	stripe_map_sector(sc, sector, &stripe, &dev_sector);
+	dev_sector += sc->stripe[stripe].physical_start;
+	dax_dev = sc->stripe[stripe].dev->dax_dev;
+	bdev = sc->stripe[stripe].dev->bdev;
+
+	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
+		return 0;
+	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
+}
+
+static void stripe_dax_flush(struct dm_target *ti, pgoff_t pgoff, void *addr,
+		size_t size)
+{
+	sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
+	struct stripe_c *sc = ti->private;
+	struct dax_device *dax_dev;
+	struct block_device *bdev;
+	uint32_t stripe;
+
+	stripe_map_sector(sc, sector, &stripe, &dev_sector);
+	dev_sector += sc->stripe[stripe].physical_start;
+	dax_dev = sc->stripe[stripe].dev->dax_dev;
+	bdev = sc->stripe[stripe].dev->bdev;
+
+	if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(size, PAGE_SIZE), &pgoff))
+		return;
+	dax_flush(dax_dev, pgoff, addr, size);
+}
+
 /*
  * Stripe status:
  *
@@ -451,6 +489,8 @@ static struct target_type stripe_target = {
 	.iterate_devices = stripe_iterate_devices,
 	.io_hints = stripe_io_hints,
 	.direct_access = stripe_dax_direct_access,
+	.dax_copy_from_iter = stripe_dax_copy_from_iter,
+	.dax_flush = stripe_dax_flush,
 };
 
 int __init dm_stripe_init(void)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 37ccd73..09b3efd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -19,6 +19,7 @@
 #include <linux/dax.h>
 #include <linux/slab.h>
 #include <linux/idr.h>
+#include <linux/uio.h>
 #include <linux/hdreg.h>
 #include <linux/delay.h>
 #include <linux/wait.h>
@@ -969,6 +970,48 @@ static long dm_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
 	return ret;
 }
 
+static size_t dm_dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	struct mapped_device *md = dax_get_private(dax_dev);
+	sector_t sector = pgoff * PAGE_SECTORS;
+	struct dm_target *ti;
+	long ret = 0;
+	int srcu_idx;
+
+	ti = dm_dax_get_live_target(md, sector, &srcu_idx);
+
+	if (!ti)
+		goto out;
+	if (!ti->type->dax_copy_from_iter) {
+		ret = copy_from_iter(addr, bytes, i);
+		goto out;
+	}
+	ret = ti->type->dax_copy_from_iter(ti, pgoff, addr, bytes, i);
+ out:
+	dm_put_live_table(md, srcu_idx);
+
+	return ret;
+}
+
+static void dm_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr,
+		size_t size)
+{
+	struct mapped_device *md = dax_get_private(dax_dev);
+	sector_t sector = pgoff * PAGE_SECTORS;
+	struct dm_target *ti;
+	int srcu_idx;
+
+	ti = dm_dax_get_live_target(md, sector, &srcu_idx);
+
+	if (!ti)
+		goto out;
+	if (ti->type->dax_flush)
+		ti->type->dax_flush(ti, pgoff, addr, size);
+ out:
+	dm_put_live_table(md, srcu_idx);
+}
+
 /*
  * A target may call dm_accept_partial_bio only from the map routine.  It is
  * allowed for all bio types except REQ_PREFLUSH.
@@ -2859,6 +2902,8 @@ static const struct block_device_operations dm_blk_dops = {
 
 static const struct dax_operations dm_dax_ops = {
 	.direct_access = dm_dax_direct_access,
+	.copy_from_iter = dm_dax_copy_from_iter,
+	.flush = dm_dax_flush,
 };
 
 /*
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 9730db4..937fafa 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -38,13 +38,13 @@ static int to_nd_device_type(struct device *dev)
 {
 	if (is_nvdimm(dev))
 		return ND_DEVICE_DIMM;
-	else if (is_nd_pmem(dev))
+	else if (is_memory(dev))
 		return ND_DEVICE_REGION_PMEM;
 	else if (is_nd_blk(dev))
 		return ND_DEVICE_REGION_BLK;
 	else if (is_nd_dax(dev))
 		return ND_DEVICE_DAX_PMEM;
-	else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
+	else if (is_nd_region(dev->parent))
 		return nd_region_to_nstype(to_nd_region(dev->parent));
 
 	return 0;
@@ -56,7 +56,7 @@ static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 	 * Ensure that region devices always have their numa node set as
 	 * early as possible.
 	 */
-	if (is_nd_pmem(dev) || is_nd_blk(dev))
+	if (is_nd_region(dev))
 		set_dev_node(dev, to_nd_region(dev)->numa_node);
 	return add_uevent_var(env, "MODALIAS=" ND_DEVICE_MODALIAS_FMT,
 			to_nd_device_type(dev));
@@ -65,7 +65,7 @@ static int nvdimm_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
 static struct module *to_bus_provider(struct device *dev)
 {
 	/* pin bus providers while regions are enabled */
-	if (is_nd_pmem(dev) || is_nd_blk(dev)) {
+	if (is_nd_region(dev)) {
 		struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
 
 		return nvdimm_bus->nd_desc->module;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index f8ad92b..4777046 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -12,8 +12,8 @@
  */
 #include <linux/device.h>
 #include <linux/sizes.h>
-#include <linux/pmem.h>
 #include "nd-core.h"
+#include "pmem.h"
 #include "pfn.h"
 #include "btt.h"
 #include "nd.h"
@@ -300,12 +300,12 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
 				cleared /= 512;
 				badblocks_clear(&nsio->bb, sector, cleared);
 			}
-			invalidate_pmem(nsio->addr + offset, size);
+			arch_invalidate_pmem(nsio->addr + offset, size);
 		} else
 			rc = -EIO;
 	}
 
-	memcpy_to_pmem(nsio->addr + offset, buf, size);
+	memcpy_flushcache(nsio->addr + offset, buf, size);
 	nvdimm_flush(to_nd_region(ndns->dev.parent));
 
 	return rc;
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index ed0bf17..7cd99b1 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -504,7 +504,7 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region,
 	struct nvdimm_bus *nvdimm_bus;
 	struct list_head *poison_list;
 
-	if (!is_nd_pmem(&nd_region->dev)) {
+	if (!is_memory(&nd_region->dev)) {
 		dev_WARN_ONCE(&nd_region->dev, 1,
 				"%s only valid for pmem regions\n", __func__);
 		return;
diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 59f6763..1bf2bd3 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -89,7 +89,7 @@ struct device *nd_dax_create(struct nd_region *nd_region)
 	struct device *dev = NULL;
 	struct nd_dax *nd_dax;
 
-	if (!is_nd_pmem(&nd_region->dev))
+	if (!is_memory(&nd_region->dev))
 		return NULL;
 
 	nd_dax = nd_dax_alloc(nd_region);
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 9852a33..f0d1b7e 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -20,6 +20,7 @@
 #include <linux/mm.h>
 #include "nd-core.h"
 #include "label.h"
+#include "pmem.h"
 #include "nd.h"
 
 static DEFINE_IDA(dimm_ida);
@@ -235,6 +236,13 @@ struct nvdimm *nd_blk_region_to_dimm(struct nd_blk_region *ndbr)
 }
 EXPORT_SYMBOL_GPL(nd_blk_region_to_dimm);
 
+unsigned long nd_blk_memremap_flags(struct nd_blk_region *ndbr)
+{
+	/* pmem mapping properties are private to libnvdimm */
+	return ARCH_MEMREMAP_PMEM;
+}
+EXPORT_SYMBOL_GPL(nd_blk_memremap_flags);
+
 struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping)
 {
 	struct nvdimm *nvdimm = nd_mapping->nvdimm;
@@ -411,7 +419,7 @@ int alias_dpa_busy(struct device *dev, void *data)
 	struct resource *res;
 	int i;
 
-	if (!is_nd_pmem(dev))
+	if (!is_memory(dev))
 		return 0;
 
 	nd_region = to_nd_region(dev);
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index c96e313..5f1c675 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -14,10 +14,10 @@
 #include <linux/device.h>
 #include <linux/sort.h>
 #include <linux/slab.h>
-#include <linux/pmem.h>
 #include <linux/list.h>
 #include <linux/nd.h>
 #include "nd-core.h"
+#include "pmem.h"
 #include "nd.h"
 
 static void namespace_io_release(struct device *dev)
@@ -112,7 +112,7 @@ static int is_uuid_busy(struct device *dev, void *data)
 
 static int is_namespace_uuid_busy(struct device *dev, void *data)
 {
-	if (is_nd_pmem(dev) || is_nd_blk(dev))
+	if (is_nd_region(dev))
 		return device_for_each_child(dev, data, is_uuid_busy);
 	return 0;
 }
@@ -155,11 +155,7 @@ bool pmem_should_map_pages(struct device *dev)
 				IORES_DESC_NONE) == REGION_MIXED)
 		return false;
 
-#ifdef ARCH_MEMREMAP_PMEM
 	return ARCH_MEMREMAP_PMEM == MEMREMAP_WB;
-#else
-	return false;
-#endif
 }
 EXPORT_SYMBOL(pmem_should_map_pages);
 
@@ -810,7 +806,7 @@ static int __reserve_free_pmem(struct device *dev, void *data)
 	struct nd_label_id label_id;
 	int i;
 
-	if (!is_nd_pmem(dev))
+	if (!is_memory(dev))
 		return 0;
 
 	nd_region = to_nd_region(dev);
@@ -2057,7 +2053,7 @@ static struct device *nd_namespace_pmem_create(struct nd_region *nd_region)
 	struct resource *res;
 	struct device *dev;
 
-	if (!is_nd_pmem(&nd_region->dev))
+	if (!is_memory(&nd_region->dev))
 		return NULL;
 
 	nspm = kzalloc(sizeof(*nspm), GFP_KERNEL);
@@ -2360,7 +2356,7 @@ static struct device **scan_labels(struct nd_region *nd_region)
 		}
 		dev->parent = &nd_region->dev;
 		devs[count++] = dev;
-	} else if (is_nd_pmem(&nd_region->dev)) {
+	} else if (is_memory(&nd_region->dev)) {
 		/* clean unselected labels */
 		for (i = 0; i < nd_region->ndr_mappings; i++) {
 			struct list_head *l, *e;
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 4c4bd20..86bc19a 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -64,7 +64,16 @@ struct blk_alloc_info {
 
 bool is_nvdimm(struct device *dev);
 bool is_nd_pmem(struct device *dev);
+bool is_nd_volatile(struct device *dev);
 bool is_nd_blk(struct device *dev);
+static inline bool is_nd_region(struct device *dev)
+{
+	return is_nd_pmem(dev) || is_nd_blk(dev) || is_nd_volatile(dev);
+}
+static inline bool is_memory(struct device *dev)
+{
+	return is_nd_pmem(dev) || is_nd_volatile(dev);
+}
 struct nvdimm_bus *walk_to_nvdimm_bus(struct device *nd_dev);
 int __init nvdimm_bus_init(void);
 void nvdimm_bus_exit(void);
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 5e40412..5fcb6f5 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -331,7 +331,7 @@ struct device *nd_pfn_create(struct nd_region *nd_region)
 	struct nd_pfn *nd_pfn;
 	struct device *dev;
 
-	if (!is_nd_pmem(&nd_region->dev))
+	if (!is_memory(&nd_region->dev))
 		return NULL;
 
 	nd_pfn = nd_pfn_alloc(nd_region);
@@ -354,7 +354,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 	if (!pfn_sb || !ndns)
 		return -ENODEV;
 
-	if (!is_nd_pmem(nd_pfn->dev.parent))
+	if (!is_memory(nd_pfn->dev.parent))
 		return -ENODEV;
 
 	if (nvdimm_read_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb), 0))
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 4a9cffc..e0f6d83 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -28,7 +28,7 @@
 #include <linux/blk-mq.h>
 #include <linux/pfn_t.h>
 #include <linux/slab.h>
-#include <linux/pmem.h>
+#include <linux/uio.h>
 #include <linux/dax.h>
 #include <linux/nd.h>
 #include "pmem.h"
@@ -72,7 +72,7 @@ static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
 			sysfs_notify_dirent(pmem->bb_state);
 	}
 
-	invalidate_pmem(pmem->virt_addr + offset, len);
+	arch_invalidate_pmem(pmem->virt_addr + offset, len);
 
 	return rc;
 }
@@ -82,7 +82,7 @@ static void write_pmem(void *pmem_addr, struct page *page,
 {
 	void *mem = kmap_atomic(page);
 
-	memcpy_to_pmem(pmem_addr, mem + off, len);
+	memcpy_flushcache(pmem_addr, mem + off, len);
 	kunmap_atomic(mem);
 }
 
@@ -237,8 +237,27 @@ static long pmem_dax_direct_access(struct dax_device *dax_dev,
 	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
 }
 
+static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter_flushcache(addr, bytes, i);
+}
+
+static void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t size)
+{
+	arch_wb_cache_pmem(addr, size);
+}
+
 static const struct dax_operations pmem_dax_ops = {
 	.direct_access = pmem_dax_direct_access,
+	.copy_from_iter = pmem_copy_from_iter,
+	.flush = pmem_dax_flush,
+};
+
+static const struct attribute_group *pmem_attribute_groups[] = {
+	&dax_attribute_group,
+	NULL,
 };
 
 static void pmem_release_queue(void *q)
@@ -267,14 +286,15 @@ static int pmem_attach_disk(struct device *dev,
 	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
 	struct nd_region *nd_region = to_nd_region(dev->parent);
 	struct vmem_altmap __altmap, *altmap = NULL;
+	int nid = dev_to_node(dev), fua, wbc;
 	struct resource *res = &nsio->res;
 	struct nd_pfn *nd_pfn = NULL;
 	struct dax_device *dax_dev;
-	int nid = dev_to_node(dev);
 	struct nd_pfn_sb *pfn_sb;
 	struct pmem_device *pmem;
 	struct resource pfn_res;
 	struct request_queue *q;
+	struct device *gendev;
 	struct gendisk *disk;
 	void *addr;
 
@@ -296,8 +316,12 @@ static int pmem_attach_disk(struct device *dev,
 	dev_set_drvdata(dev, pmem);
 	pmem->phys_addr = res->start;
 	pmem->size = resource_size(res);
-	if (nvdimm_has_flush(nd_region) < 0)
+	fua = nvdimm_has_flush(nd_region);
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
 		dev_warn(dev, "unable to guarantee persistence of writes\n");
+		fua = 0;
+	}
+	wbc = nvdimm_has_cache(nd_region);
 
 	if (!devm_request_mem_region(dev, res->start, resource_size(res),
 				dev_name(&ndns->dev))) {
@@ -341,7 +365,7 @@ static int pmem_attach_disk(struct device *dev,
 		return PTR_ERR(addr);
 	pmem->virt_addr = addr;
 
-	blk_queue_write_cache(q, true, true);
+	blk_queue_write_cache(q, wbc, fua);
 	blk_queue_make_request(q, pmem_make_request);
 	blk_queue_physical_block_size(q, PAGE_SIZE);
 	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
@@ -372,8 +396,12 @@ static int pmem_attach_disk(struct device *dev,
 		put_disk(disk);
 		return -ENOMEM;
 	}
+	dax_write_cache(dax_dev, wbc);
 	pmem->dax_dev = dax_dev;
 
+	gendev = disk_to_dev(disk);
+	gendev->groups = pmem_attribute_groups;
+
 	device_add_disk(dev, disk);
 	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
 		return -ENOMEM;
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index c5917f0..5434321 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -5,6 +5,20 @@
 #include <linux/pfn_t.h>
 #include <linux/fs.h>
 
+#ifdef CONFIG_ARCH_HAS_PMEM_API
+#define ARCH_MEMREMAP_PMEM MEMREMAP_WB
+void arch_wb_cache_pmem(void *addr, size_t size);
+void arch_invalidate_pmem(void *addr, size_t size);
+#else
+#define ARCH_MEMREMAP_PMEM MEMREMAP_WT
+static inline void arch_wb_cache_pmem(void *addr, size_t size)
+{
+}
+static inline void arch_invalidate_pmem(void *addr, size_t size)
+{
+}
+#endif
+
 /* this definition is in it's own header for tools/testing/nvdimm to consume */
 struct pmem_device {
 	/* One contiguous memory region per device */
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index ab141f8..5954cfb 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -15,7 +15,6 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/hash.h>
-#include <linux/pmem.h>
 #include <linux/sort.h>
 #include <linux/io.h>
 #include <linux/nd.h>
@@ -169,6 +168,11 @@ bool is_nd_blk(struct device *dev)
 	return dev ? dev->type == &nd_blk_device_type : false;
 }
 
+bool is_nd_volatile(struct device *dev)
+{
+	return dev ? dev->type == &nd_volatile_device_type : false;
+}
+
 struct nd_region *to_nd_region(struct device *dev)
 {
 	struct nd_region *nd_region = container_of(dev, struct nd_region, dev);
@@ -215,7 +219,7 @@ EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
  */
 int nd_region_to_nstype(struct nd_region *nd_region)
 {
-	if (is_nd_pmem(&nd_region->dev)) {
+	if (is_memory(&nd_region->dev)) {
 		u16 i, alias;
 
 		for (i = 0, alias = 0; i < nd_region->ndr_mappings; i++) {
@@ -243,7 +247,7 @@ static ssize_t size_show(struct device *dev,
 	struct nd_region *nd_region = to_nd_region(dev);
 	unsigned long long size = 0;
 
-	if (is_nd_pmem(dev)) {
+	if (is_memory(dev)) {
 		size = nd_region->ndr_size;
 	} else if (nd_region->ndr_mappings == 1) {
 		struct nd_mapping *nd_mapping = &nd_region->mapping[0];
@@ -309,7 +313,7 @@ static ssize_t set_cookie_show(struct device *dev,
 	struct nd_interleave_set *nd_set = nd_region->nd_set;
 	ssize_t rc = 0;
 
-	if (is_nd_pmem(dev) && nd_set)
+	if (is_memory(dev) && nd_set)
 		/* pass, should be precluded by region_visible */;
 	else
 		return -ENXIO;
@@ -363,7 +367,7 @@ resource_size_t nd_region_available_dpa(struct nd_region *nd_region)
 		if (!ndd)
 			return 0;
 
-		if (is_nd_pmem(&nd_region->dev)) {
+		if (is_memory(&nd_region->dev)) {
 			available += nd_pmem_available_dpa(nd_region,
 					nd_mapping, &overlap);
 			if (overlap > blk_max_overlap) {
@@ -549,10 +553,10 @@ static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
 	struct nd_interleave_set *nd_set = nd_region->nd_set;
 	int type = nd_region_to_nstype(nd_region);
 
-	if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
+	if (!is_memory(dev) && a == &dev_attr_pfn_seed.attr)
 		return 0;
 
-	if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
+	if (!is_memory(dev) && a == &dev_attr_dax_seed.attr)
 		return 0;
 
 	if (!is_nd_pmem(dev) && a == &dev_attr_badblocks.attr)
@@ -580,7 +584,7 @@ static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
 				|| type == ND_DEVICE_NAMESPACE_BLK)
 			&& a == &dev_attr_available_size.attr)
 		return a->mode;
-	else if (is_nd_pmem(dev) && nd_set)
+	else if (is_memory(dev) && nd_set)
 		return a->mode;
 
 	return 0;
@@ -637,7 +641,7 @@ static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
 {
 	struct nd_region *nd_region;
 
-	if (!probe && (is_nd_pmem(dev) || is_nd_blk(dev))) {
+	if (!probe && is_nd_region(dev)) {
 		int i;
 
 		nd_region = to_nd_region(dev);
@@ -655,12 +659,8 @@ static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
 			if (ndd)
 				atomic_dec(&nvdimm->busy);
 		}
-
-		if (is_nd_pmem(dev))
-			return;
 	}
-	if (dev->parent && (is_nd_blk(dev->parent) || is_nd_pmem(dev->parent))
-			&& probe) {
+	if (dev->parent && is_nd_region(dev->parent) && probe) {
 		nd_region = to_nd_region(dev->parent);
 		nvdimm_bus_lock(dev);
 		if (nd_region->ns_seed == dev)
@@ -1048,8 +1048,8 @@ void nvdimm_flush(struct nd_region *nd_region)
 	 * The first wmb() is needed to 'sfence' all previous writes
 	 * such that they are architecturally visible for the platform
 	 * buffer flush.  Note that we've already arranged for pmem
-	 * writes to avoid the cache via arch_memcpy_to_pmem().  The
-	 * final wmb() ensures ordering for the NVDIMM flush write.
+	 * writes to avoid the cache via memcpy_flushcache().  The final
+	 * wmb() ensures ordering for the NVDIMM flush write.
 	 */
 	wmb();
 	for (i = 0; i < nd_region->ndr_mappings; i++)
@@ -1071,8 +1071,9 @@ int nvdimm_has_flush(struct nd_region *nd_region)
 {
 	int i;
 
-	/* no nvdimm == flushing capability unknown */
-	if (nd_region->ndr_mappings == 0)
+	/* no nvdimm or pmem api == flushing capability unknown */
+	if (nd_region->ndr_mappings == 0
+			|| !IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API))
 		return -ENXIO;
 
 	for (i = 0; i < nd_region->ndr_mappings; i++) {
@@ -1092,6 +1093,12 @@ int nvdimm_has_flush(struct nd_region *nd_region)
 }
 EXPORT_SYMBOL_GPL(nvdimm_has_flush);
 
+int nvdimm_has_cache(struct nd_region *nd_region)
+{
+	return is_nd_pmem(&nd_region->dev);
+}
+EXPORT_SYMBOL_GPL(nvdimm_has_cache);
+
 void __exit nd_region_devs_exit(void)
 {
 	ida_destroy(&region_ida);
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 36e5280..88fa7b3 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -18,6 +18,7 @@
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/pfn_t.h>
+#include <linux/uio.h>
 #include <linux/dax.h>
 #include <asm/extmem.h>
 #include <asm/io.h>
@@ -43,8 +44,15 @@ static const struct block_device_operations dcssblk_devops = {
 	.release 	= dcssblk_release,
 };
 
+static size_t dcssblk_dax_copy_from_iter(struct dax_device *dax_dev,
+		pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter(addr, bytes, i);
+}
+
 static const struct dax_operations dcssblk_dax_ops = {
 	.direct_access = dcssblk_dax_direct_access,
+	.copy_from_iter = dcssblk_dax_copy_from_iter,
 };
 
 struct dcssblk_dev_info {