Merge tag 'libnvdimm-for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:

 - Asynchronous address range scrub:

     Given the capacities of next generation persistent memory devices a
     scrub operation to find all poison may take 10s of seconds.  We
     want this scrub work to be done asynchronously with the rest of
     system initialization, so we move it out of line from the NFIT
     probing, i.e. acpi_nfit_add().

 - Clear poison:

     ACPI 6.1 introduces the ability to send "clear error" commands to
     the ACPI0012:00 device representing the root of an "nvdimm bus".
     Similar to relocating a bad block on a disk, this support clears
     media errors in response to a write.

 - Persistent memory resource tracking:

     A persistent memory range may be designated as simply "reserved" by
     platform firmware in the efi/e820 memory map.  Later when the NFIT
     driver loads it discovers that the range is "Persistent Memory".

     The NFIT bus driver inserts a resource to advertise that
     "persistent" attribute in the system resource tree for /proc/iomem
     and kernel-internal usages.

 - Miscellaneous cleanups and fixes:

     Workaround section misaligned pmem ranges when allocating a struct
     page memmap, fix handling of the read-only case in the ioctl path,
     and clean up block device major number allocation.

* tag 'libnvdimm-for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (26 commits)
  libnvdimm, pmem: clear poison on write
  libnvdimm, pmem: fix kmap_atomic() leak in error path
  nvdimm/btt: don't allocate unused major device number
  nvdimm/blk: don't allocate unused major device number
  pmem: don't allocate unused major device number
  ACPI: Change NFIT driver to insert new resource
  resource: Export insert_resource and remove_resource
  resource: Add remove_resource interface
  resource: Change __request_region to inherit from immediate parent
  libnvdimm, pmem: fix ia64 build, use PHYS_PFN
  nfit, libnvdimm: clear poison command support
  libnvdimm, pfn: 'resource'-address and 'size' attributes for pfn devices
  libnvdimm, pmem: adjust for section collisions with 'System RAM'
  libnvdimm, pmem: fix 'pfn' support for section-misaligned namespaces
  libnvdimm: Fix security issue with DSM IOCTL.
  libnvdimm: Clean-up access mode check.
  tools/testing/nvdimm: expand ars unit testing
  nfit: disable userspace initiated ars during scrub
  nfit: scrub and register regions in a workqueue
  nfit, libnvdimm: async region scrub workqueue
  ...

21 files changed, 1394 insertions, 439 deletions

diff --git a/arch/x86/include/asm/pmem.h b/arch/x86/include/asm/pmem.h
index c57fd1ea9689..bf8b35d2035a 100644
--- a/arch/x86/include/asm/pmem.h
+++ b/arch/x86/include/asm/pmem.h
@@ -137,6 +137,11 @@ static inline void arch_clear_pmem(void __pmem *addr, size_t size)
 	arch_wb_cache_pmem(addr, size);
 }
 
+static inline void arch_invalidate_pmem(void __pmem *addr, size_t size)
+{
+	clflush_cache_range((void __force *) addr, size);
+}
+
 static inline bool __arch_has_wmb_pmem(void)
 {
 	/*
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 35947ac87644..d0f35e63640b 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -21,6 +21,7 @@
 #include <linux/sort.h>
 #include <linux/pmem.h>
 #include <linux/io.h>
+#include <linux/nd.h>
 #include <asm/cacheflush.h>
 #include "nfit.h"
 
@@ -34,6 +35,18 @@ static bool force_enable_dimms;
 module_param(force_enable_dimms, bool, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(force_enable_dimms, "Ignore _STA (ACPI DIMM device) status");
 
+static unsigned int scrub_timeout = NFIT_ARS_TIMEOUT;
+module_param(scrub_timeout, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(scrub_timeout, "Initial scrub timeout in seconds");
+
+/* after three payloads of overflow, it's dead jim */
+static unsigned int scrub_overflow_abort = 3;
+module_param(scrub_overflow_abort, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(scrub_overflow_abort,
+		"Number of times we overflow ARS results before abort");
+
+static struct workqueue_struct *nfit_wq;
+
 struct nfit_table_prev {
 	struct list_head spas;
 	struct list_head memdevs;
@@ -72,9 +85,90 @@ static struct acpi_device *to_acpi_dev(struct acpi_nfit_desc *acpi_desc)
 	return to_acpi_device(acpi_desc->dev);
 }
 
+static int xlat_status(void *buf, unsigned int cmd)
+{
+	struct nd_cmd_clear_error *clear_err;
+	struct nd_cmd_ars_status *ars_status;
+	struct nd_cmd_ars_start *ars_start;
+	struct nd_cmd_ars_cap *ars_cap;
+	u16 flags;
+
+	switch (cmd) {
+	case ND_CMD_ARS_CAP:
+		ars_cap = buf;
+		if ((ars_cap->status & 0xffff) == NFIT_ARS_CAP_NONE)
+			return -ENOTTY;
+
+		/* Command failed */
+		if (ars_cap->status & 0xffff)
+			return -EIO;
+
+		/* No supported scan types for this range */
+		flags = ND_ARS_PERSISTENT | ND_ARS_VOLATILE;
+		if ((ars_cap->status >> 16 & flags) == 0)
+			return -ENOTTY;
+		break;
+	case ND_CMD_ARS_START:
+		ars_start = buf;
+		/* ARS is in progress */
+		if ((ars_start->status & 0xffff) == NFIT_ARS_START_BUSY)
+			return -EBUSY;
+
+		/* Command failed */
+		if (ars_start->status & 0xffff)
+			return -EIO;
+		break;
+	case ND_CMD_ARS_STATUS:
+		ars_status = buf;
+		/* Command failed */
+		if (ars_status->status & 0xffff)
+			return -EIO;
+		/* Check extended status (Upper two bytes) */
+		if (ars_status->status == NFIT_ARS_STATUS_DONE)
+			return 0;
+
+		/* ARS is in progress */
+		if (ars_status->status == NFIT_ARS_STATUS_BUSY)
+			return -EBUSY;
+
+		/* No ARS performed for the current boot */
+		if (ars_status->status == NFIT_ARS_STATUS_NONE)
+			return -EAGAIN;
+
+		/*
+		 * ARS interrupted, either we overflowed or some other
+		 * agent wants the scan to stop.  If we didn't overflow
+		 * then just continue with the returned results.
+		 */
+		if (ars_status->status == NFIT_ARS_STATUS_INTR) {
+			if (ars_status->flags & NFIT_ARS_F_OVERFLOW)
+				return -ENOSPC;
+			return 0;
+		}
+
+		/* Unknown status */
+		if (ars_status->status >> 16)
+			return -EIO;
+		break;
+	case ND_CMD_CLEAR_ERROR:
+		clear_err = buf;
+		if (clear_err->status & 0xffff)
+			return -EIO;
+		if (!clear_err->cleared)
+			return -EIO;
+		if (clear_err->length > clear_err->cleared)
+			return clear_err->cleared;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
 static int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd, void *buf,
-		unsigned int buf_len)
+		unsigned int buf_len, int *cmd_rc)
 {
 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
 	const struct nd_cmd_desc *desc = NULL;
@@ -185,6 +279,8 @@ static int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc,
 			 * unfilled in the output buffer
 			 */
 			rc = buf_len - offset - in_buf.buffer.length;
+			if (cmd_rc)
+				*cmd_rc = xlat_status(buf, cmd);
 		} else {
 			dev_err(dev, "%s:%s underrun cmd: %s buf_len: %d out_len: %d\n",
 					__func__, dimm_name, cmd_name, buf_len,
@@ -675,12 +771,11 @@ static struct attribute_group acpi_nfit_attribute_group = {
 	.attrs = acpi_nfit_attributes,
 };
 
-const struct attribute_group *acpi_nfit_attribute_groups[] = {
+static const struct attribute_group *acpi_nfit_attribute_groups[] = {
 	&nvdimm_bus_attribute_group,
 	&acpi_nfit_attribute_group,
 	NULL,
 };
-EXPORT_SYMBOL_GPL(acpi_nfit_attribute_groups);
 
 static struct acpi_nfit_memory_map *to_nfit_memdev(struct device *dev)
 {
@@ -917,7 +1012,7 @@ static void acpi_nfit_init_dsms(struct acpi_nfit_desc *acpi_desc)
 	if (!adev)
 		return;
 
-	for (i = ND_CMD_ARS_CAP; i <= ND_CMD_ARS_STATUS; i++)
+	for (i = ND_CMD_ARS_CAP; i <= ND_CMD_CLEAR_ERROR; i++)
 		if (acpi_check_dsm(adev->handle, uuid, 1, 1ULL << i))
 			set_bit(i, &nd_desc->dsm_mask);
 }
@@ -1105,7 +1200,7 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
 	writeq(cmd, mmio->addr.base + offset);
 	wmb_blk(nfit_blk);
 
-	if (nfit_blk->dimm_flags & ND_BLK_DCR_LATCH)
+	if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
 		readq(mmio->addr.base + offset);
 }
 
@@ -1141,7 +1236,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
 			memcpy_to_pmem(mmio->addr.aperture + offset,
 					iobuf + copied, c);
 		else {
-			if (nfit_blk->dimm_flags & ND_BLK_READ_FLUSH)
+			if (nfit_blk->dimm_flags & NFIT_BLK_READ_FLUSH)
 				mmio_flush_range((void __force *)
 					mmio->addr.aperture + offset, c);
 
@@ -1328,13 +1423,13 @@ static int acpi_nfit_blk_get_flags(struct nvdimm_bus_descriptor *nd_desc,
 
 	memset(&flags, 0, sizeof(flags));
 	rc = nd_desc->ndctl(nd_desc, nvdimm, ND_CMD_DIMM_FLAGS, &flags,
-			sizeof(flags));
+			sizeof(flags), NULL);
 
 	if (rc >= 0 && flags.status == 0)
 		nfit_blk->dimm_flags = flags.flags;
 	else if (rc == -ENOTTY) {
 		/* fall back to a conservative default */
-		nfit_blk->dimm_flags = ND_BLK_DCR_LATCH | ND_BLK_READ_FLUSH;
+		nfit_blk->dimm_flags = NFIT_BLK_DCR_LATCH | NFIT_BLK_READ_FLUSH;
 		rc = 0;
 	} else
 		rc = -ENXIO;
@@ -1473,93 +1568,85 @@ static void acpi_nfit_blk_region_disable(struct nvdimm_bus *nvdimm_bus,
 	/* devm will free nfit_blk */
 }
 
-static int ars_get_cap(struct nvdimm_bus_descriptor *nd_desc,
-		struct nd_cmd_ars_cap *cmd, u64 addr, u64 length)
+static int ars_get_cap(struct acpi_nfit_desc *acpi_desc,
+		struct nd_cmd_ars_cap *cmd, struct nfit_spa *nfit_spa)
 {
-	cmd->address = addr;
-	cmd->length = length;
+	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
+	int cmd_rc, rc;
 
-	return nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, cmd,
-			sizeof(*cmd));
+	cmd->address = spa->address;
+	cmd->length = spa->length;
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, cmd,
+			sizeof(*cmd), &cmd_rc);
+	if (rc < 0)
+		return rc;
+	return cmd_rc;
 }
 
-static int ars_do_start(struct nvdimm_bus_descriptor *nd_desc,
-		struct nd_cmd_ars_start *cmd, u64 addr, u64 length)
+static int ars_start(struct acpi_nfit_desc *acpi_desc, struct nfit_spa *nfit_spa)
 {
 	int rc;
+	int cmd_rc;
+	struct nd_cmd_ars_start ars_start;
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
+	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
 
-	cmd->address = addr;
-	cmd->length = length;
-	cmd->type = ND_ARS_PERSISTENT;
+	memset(&ars_start, 0, sizeof(ars_start));
+	ars_start.address = spa->address;
+	ars_start.length = spa->length;
+	if (nfit_spa_type(spa) == NFIT_SPA_PM)
+		ars_start.type = ND_ARS_PERSISTENT;
+	else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE)
+		ars_start.type = ND_ARS_VOLATILE;
+	else
+		return -ENOTTY;
 
-	while (1) {
-		rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, cmd,
-				sizeof(*cmd));
-		if (rc)
-			return rc;
-		switch (cmd->status) {
-		case 0:
-			return 0;
-		case 1:
-			/* ARS unsupported, but we should never get here */
-			return 0;
-		case 6:
-			/* ARS is in progress */
-			msleep(1000);
-			break;
-		default:
-			return -ENXIO;
-		}
-	}
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
+			sizeof(ars_start), &cmd_rc);
+
+	if (rc < 0)
+		return rc;
+	return cmd_rc;
 }
 
-static int ars_get_status(struct nvdimm_bus_descriptor *nd_desc,
-		struct nd_cmd_ars_status *cmd, u32 size)
+static int ars_continue(struct acpi_nfit_desc *acpi_desc)
 {
-	int rc;
+	int rc, cmd_rc;
+	struct nd_cmd_ars_start ars_start;
+	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
+	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
+
+	memset(&ars_start, 0, sizeof(ars_start));
+	ars_start.address = ars_status->restart_address;
+	ars_start.length = ars_status->restart_length;
+	ars_start.type = ars_status->type;
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_START, &ars_start,
+			sizeof(ars_start), &cmd_rc);
+	if (rc < 0)
+		return rc;
+	return cmd_rc;
+}
 
-	while (1) {
-		rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, cmd,
-			size);
-		if (rc || cmd->status & 0xffff)
-			return -ENXIO;
+static int ars_get_status(struct acpi_nfit_desc *acpi_desc)
+{
+	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
+	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
+	int rc, cmd_rc;
 
-		/* Check extended status (Upper two bytes) */
-		switch (cmd->status >> 16) {
-		case 0:
-			return 0;
-		case 1:
-			/* ARS is in progress */
-			msleep(1000);
-			break;
-		case 2:
-			/* No ARS performed for the current boot */
-			return 0;
-		case 3:
-			/* TODO: error list overflow support */
-		default:
-			return -ENXIO;
-		}
-	}
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, ars_status,
+			acpi_desc->ars_status_size, &cmd_rc);
+	if (rc < 0)
+		return rc;
+	return cmd_rc;
 }
 
 static int ars_status_process_records(struct nvdimm_bus *nvdimm_bus,
-		struct nd_cmd_ars_status *ars_status, u64 start)
+		struct nd_cmd_ars_status *ars_status)
 {
 	int rc;
 	u32 i;
 
-	/*
-	 * The address field returned by ars_status should be either
-	 * less than or equal to the address we last started ARS for.
-	 * The (start, length) returned by ars_status should also have
-	 * non-zero overlap with the range we started ARS for.
-	 * If this is not the case, bail.
-	 */
-	if (ars_status->address > start ||
-			(ars_status->address + ars_status->length < start))
-		return -ENXIO;
-
 	for (i = 0; i < ars_status->num_records; i++) {
 		rc = nvdimm_bus_add_poison(nvdimm_bus,
 				ars_status->records[i].err_address,
@@ -1571,118 +1658,56 @@ static int ars_status_process_records(struct nvdimm_bus *nvdimm_bus,
 	return 0;
 }
 
-static int acpi_nfit_find_poison(struct acpi_nfit_desc *acpi_desc,
-		struct nd_region_desc *ndr_desc)
+static void acpi_nfit_remove_resource(void *data)
 {
-	struct nvdimm_bus_descriptor *nd_desc = &acpi_desc->nd_desc;
-	struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
-	struct nd_cmd_ars_status *ars_status = NULL;
-	struct nd_cmd_ars_start *ars_start = NULL;
-	struct nd_cmd_ars_cap *ars_cap = NULL;
-	u64 start, len, cur, remaining;
-	u32 ars_status_size;
-	int rc;
-
-	ars_cap = kzalloc(sizeof(*ars_cap), GFP_KERNEL);
-	if (!ars_cap)
-		return -ENOMEM;
+	struct resource *res = data;
 
-	start = ndr_desc->res->start;
-	len = ndr_desc->res->end - ndr_desc->res->start + 1;
-
-	/*
-	 * If ARS is unimplemented, unsupported, or if the 'Persistent Memory
-	 * Scrub' flag in extended status is not set, skip this but continue
-	 * initialization
-	 */
-	rc = ars_get_cap(nd_desc, ars_cap, start, len);
-	if (rc == -ENOTTY) {
-		dev_dbg(acpi_desc->dev,
-			"Address Range Scrub is not implemented, won't create an error list\n");
-		rc = 0;
-		goto out;
-	}
-	if (rc)
-		goto out;
-
-	if ((ars_cap->status & 0xffff) ||
-		!(ars_cap->status >> 16 & ND_ARS_PERSISTENT)) {
-		dev_warn(acpi_desc->dev,
-			"ARS unsupported (status: 0x%x), won't create an error list\n",
-			ars_cap->status);
-		goto out;
-	}
-
-	/*
-	 * Check if a full-range ARS has been run. If so, use those results
-	 * without having to start a new ARS.
-	 */
-	ars_status_size = ars_cap->max_ars_out;
-	ars_status = kzalloc(ars_status_size, GFP_KERNEL);
-	if (!ars_status) {
-		rc = -ENOMEM;
-		goto out;
-	}
+	remove_resource(res);
+}
 
-	rc = ars_get_status(nd_desc, ars_status, ars_status_size);
-	if (rc)
-		goto out;
+static int acpi_nfit_insert_resource(struct acpi_nfit_desc *acpi_desc,
+		struct nd_region_desc *ndr_desc)
+{
+	struct resource *res, *nd_res = ndr_desc->res;
+	int is_pmem, ret;
 
-	if (ars_status->address <= start &&
-		(ars_status->address + ars_status->length >= start + len)) {
-		rc = ars_status_process_records(nvdimm_bus, ars_status, start);
-		goto out;
-	}
+	/* No operation if the region is already registered as PMEM */
+	is_pmem = region_intersects(nd_res->start, resource_size(nd_res),
+				IORESOURCE_MEM, IORES_DESC_PERSISTENT_MEMORY);
+	if (is_pmem == REGION_INTERSECTS)
+		return 0;
 
-	/*
-	 * ARS_STATUS can overflow if the number of poison entries found is
-	 * greater than the maximum buffer size (ars_cap->max_ars_out)
-	 * To detect overflow, check if the length field of ars_status
-	 * is less than the length we supplied. If so, process the
-	 * error entries we got, adjust the start point, and start again
-	 */
-	ars_start = kzalloc(sizeof(*ars_start), GFP_KERNEL);
-	if (!ars_start)
+	res = devm_kzalloc(acpi_desc->dev, sizeof(*res), GFP_KERNEL);
+	if (!res)
 		return -ENOMEM;
 
-	cur = start;
-	remaining = len;
-	do {
-		u64 done, end;
-
-		rc = ars_do_start(nd_desc, ars_start, cur, remaining);
-		if (rc)
-			goto out;
-
-		rc = ars_get_status(nd_desc, ars_status, ars_status_size);
-		if (rc)
-			goto out;
+	res->name = "Persistent Memory";
+	res->start = nd_res->start;
+	res->end = nd_res->end;
+	res->flags = IORESOURCE_MEM;
+	res->desc = IORES_DESC_PERSISTENT_MEMORY;
 
-		rc = ars_status_process_records(nvdimm_bus, ars_status, cur);
-		if (rc)
-			goto out;
+	ret = insert_resource(&iomem_resource, res);
+	if (ret)
+		return ret;
 
-		end = min(cur + remaining,
-			ars_status->address + ars_status->length);
-		done = end - cur;
-		cur += done;
-		remaining -= done;
-	} while (remaining);
+	ret = devm_add_action(acpi_desc->dev, acpi_nfit_remove_resource, res);
+	if (ret) {
+		remove_resource(res);
+		return ret;
+	}
 
- out:
-	kfree(ars_cap);
-	kfree(ars_start);
-	kfree(ars_status);
-	return rc;
+	return 0;
 }
 
 static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
 		struct nd_mapping *nd_mapping, struct nd_region_desc *ndr_desc,
 		struct acpi_nfit_memory_map *memdev,
-		struct acpi_nfit_system_address *spa)
+		struct nfit_spa *nfit_spa)
 {
 	struct nvdimm *nvdimm = acpi_nfit_dimm_by_handle(acpi_desc,
 			memdev->device_handle);
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
 	struct nd_blk_region_desc *ndbr_desc;
 	struct nfit_mem *nfit_mem;
 	int blk_valid = 0;
@@ -1718,7 +1743,9 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
 		ndbr_desc->enable = acpi_nfit_blk_region_enable;
 		ndbr_desc->disable = acpi_nfit_blk_region_disable;
 		ndbr_desc->do_io = acpi_desc->blk_do_io;
-		if (!nvdimm_blk_region_create(acpi_desc->nvdimm_bus, ndr_desc))
+		nfit_spa->nd_region = nvdimm_blk_region_create(acpi_desc->nvdimm_bus,
+				ndr_desc);
+		if (!nfit_spa->nd_region)
 			return -ENOMEM;
 		break;
 	}
@@ -1738,7 +1765,7 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 	struct resource res;
 	int count = 0, rc;
 
-	if (nfit_spa->is_registered)
+	if (nfit_spa->nd_region)
 		return 0;
 
 	if (spa->range_index == 0) {
@@ -1775,47 +1802,332 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 		}
 		nd_mapping = &nd_mappings[count++];
 		rc = acpi_nfit_init_mapping(acpi_desc, nd_mapping, ndr_desc,
-				memdev, spa);
+				memdev, nfit_spa);
 		if (rc)
-			return rc;
+			goto out;
 	}
 
 	ndr_desc->nd_mapping = nd_mappings;
 	ndr_desc->num_mappings = count;
 	rc = acpi_nfit_init_interleave_set(acpi_desc, ndr_desc, spa);
 	if (rc)
-		return rc;
+		goto out;
 
 	nvdimm_bus = acpi_desc->nvdimm_bus;
 	if (nfit_spa_type(spa) == NFIT_SPA_PM) {
-		rc = acpi_nfit_find_poison(acpi_desc, ndr_desc);
+		rc = acpi_nfit_insert_resource(acpi_desc, ndr_desc);
 		if (rc) {
-			dev_err(acpi_desc->dev,
-				"error while performing ARS to find poison: %d\n",
+			dev_warn(acpi_desc->dev,
+				"failed to insert pmem resource to iomem: %d\n",
 				rc);
-			return rc;
+			goto out;
 		}
-		if (!nvdimm_pmem_region_create(nvdimm_bus, ndr_desc))
-			return -ENOMEM;
+
+		nfit_spa->nd_region = nvdimm_pmem_region_create(nvdimm_bus,
+				ndr_desc);
+		if (!nfit_spa->nd_region)
+			rc = -ENOMEM;
 	} else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE) {
-		if (!nvdimm_volatile_region_create(nvdimm_bus, ndr_desc))
-			return -ENOMEM;
+		nfit_spa->nd_region = nvdimm_volatile_region_create(nvdimm_bus,
+				ndr_desc);
+		if (!nfit_spa->nd_region)
+			rc = -ENOMEM;
 	}
 
-	nfit_spa->is_registered = 1;
+ out:
+	if (rc)
+		dev_err(acpi_desc->dev, "failed to register spa range %d\n",
+				nfit_spa->spa->range_index);
+	return rc;
+}
+
+static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc,
+		u32 max_ars)
+{
+	struct device *dev = acpi_desc->dev;
+	struct nd_cmd_ars_status *ars_status;
+
+	if (acpi_desc->ars_status && acpi_desc->ars_status_size >= max_ars) {
+		memset(acpi_desc->ars_status, 0, acpi_desc->ars_status_size);
+		return 0;
+	}
+
+	if (acpi_desc->ars_status)
+		devm_kfree(dev, acpi_desc->ars_status);
+	acpi_desc->ars_status = NULL;
+	ars_status = devm_kzalloc(dev, max_ars, GFP_KERNEL);
+	if (!ars_status)
+		return -ENOMEM;
+	acpi_desc->ars_status = ars_status;
+	acpi_desc->ars_status_size = max_ars;
 	return 0;
 }
 
-static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
+static int acpi_nfit_query_poison(struct acpi_nfit_desc *acpi_desc,
+		struct nfit_spa *nfit_spa)
 {
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
+	int rc;
+
+	if (!nfit_spa->max_ars) {
+		struct nd_cmd_ars_cap ars_cap;
+
+		memset(&ars_cap, 0, sizeof(ars_cap));
+		rc = ars_get_cap(acpi_desc, &ars_cap, nfit_spa);
+		if (rc < 0)
+			return rc;
+		nfit_spa->max_ars = ars_cap.max_ars_out;
+		nfit_spa->clear_err_unit = ars_cap.clear_err_unit;
+		/* check that the supported scrub types match the spa type */
+		if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE &&
+				((ars_cap.status >> 16) & ND_ARS_VOLATILE) == 0)
+			return -ENOTTY;
+		else if (nfit_spa_type(spa) == NFIT_SPA_PM &&
+				((ars_cap.status >> 16) & ND_ARS_PERSISTENT) == 0)
+			return -ENOTTY;
+	}
+
+	if (ars_status_alloc(acpi_desc, nfit_spa->max_ars))
+		return -ENOMEM;
+
+	rc = ars_get_status(acpi_desc);
+	if (rc < 0 && rc != -ENOSPC)
+		return rc;
+
+	if (ars_status_process_records(acpi_desc->nvdimm_bus,
+				acpi_desc->ars_status))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc,
+		struct nfit_spa *nfit_spa)
+{
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
+	unsigned int overflow_retry = scrub_overflow_abort;
+	u64 init_ars_start = 0, init_ars_len = 0;
+	struct device *dev = acpi_desc->dev;
+	unsigned int tmo = scrub_timeout;
+	int rc;
+
+	if (nfit_spa->ars_done || !nfit_spa->nd_region)
+		return;
+
+	rc = ars_start(acpi_desc, nfit_spa);
+	/*
+	 * If we timed out the initial scan we'll still be busy here,
+	 * and will wait another timeout before giving up permanently.
+	 */
+	if (rc < 0 && rc != -EBUSY)
+		return;
+
+	do {
+		u64 ars_start, ars_len;
+
+		if (acpi_desc->cancel)
+			break;
+		rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
+		if (rc == -ENOTTY)
+			break;
+		if (rc == -EBUSY && !tmo) {
+			dev_warn(dev, "range %d ars timeout, aborting\n",
+					spa->range_index);
+			break;
+		}
+
+		if (rc == -EBUSY) {
+			/*
+			 * Note, entries may be appended to the list
+			 * while the lock is dropped, but the workqueue
+			 * being active prevents entries being deleted /
+			 * freed.
+			 */
+			mutex_unlock(&acpi_desc->init_mutex);
+			ssleep(1);
+			tmo--;
+			mutex_lock(&acpi_desc->init_mutex);
+			continue;
+		}
+
+		/* we got some results, but there are more pending... */
+		if (rc == -ENOSPC && overflow_retry--) {
+			if (!init_ars_len) {
+				init_ars_len = acpi_desc->ars_status->length;
+				init_ars_start = acpi_desc->ars_status->address;
+			}
+			rc = ars_continue(acpi_desc);
+		}
+
+		if (rc < 0) {
+			dev_warn(dev, "range %d ars continuation failed\n",
+					spa->range_index);
+			break;
+		}
+
+		if (init_ars_len) {
+			ars_start = init_ars_start;
+			ars_len = init_ars_len;
+		} else {
+			ars_start = acpi_desc->ars_status->address;
+			ars_len = acpi_desc->ars_status->length;
+		}
+		dev_dbg(dev, "spa range: %d ars from %#llx + %#llx complete\n",
+				spa->range_index, ars_start, ars_len);
+		/* notify the region about new poison entries */
+		nvdimm_region_notify(nfit_spa->nd_region,
+				NVDIMM_REVALIDATE_POISON);
+		break;
+	} while (1);
+}
+
+static void acpi_nfit_scrub(struct work_struct *work)
+{
+	struct device *dev;
+	u64 init_scrub_length = 0;
 	struct nfit_spa *nfit_spa;
+	u64 init_scrub_address = 0;
+	bool init_ars_done = false;
+	struct acpi_nfit_desc *acpi_desc;
+	unsigned int tmo = scrub_timeout;
+	unsigned int overflow_retry = scrub_overflow_abort;
+
+	acpi_desc = container_of(work, typeof(*acpi_desc), work);
+	dev = acpi_desc->dev;
 
+	/*
+	 * We scrub in 2 phases.  The first phase waits for any platform
+	 * firmware initiated scrubs to complete and then we go search for the
+	 * affected spa regions to mark them scanned.  In the second phase we
+	 * initiate a directed scrub for every range that was not scrubbed in
+	 * phase 1.
+	 */
+
+	/* process platform firmware initiated scrubs */
+ retry:
+	mutex_lock(&acpi_desc->init_mutex);
 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
-		int rc = acpi_nfit_register_region(acpi_desc, nfit_spa);
+		struct nd_cmd_ars_status *ars_status;
+		struct acpi_nfit_system_address *spa;
+		u64 ars_start, ars_len;
+		int rc;
 
-		if (rc)
-			return rc;
+		if (acpi_desc->cancel)
+			break;
+
+		if (nfit_spa->nd_region)
+			continue;
+
+		if (init_ars_done) {
+			/*
+			 * No need to re-query, we're now just
+			 * reconciling all the ranges covered by the
+			 * initial scrub
+			 */
+			rc = 0;
+		} else
+			rc = acpi_nfit_query_poison(acpi_desc, nfit_spa);
+
+		if (rc == -ENOTTY) {
+			/* no ars capability, just register spa and move on */
+			acpi_nfit_register_region(acpi_desc, nfit_spa);
+			continue;
+		}
+
+		if (rc == -EBUSY && !tmo) {
+			/* fallthrough to directed scrub in phase 2 */
+			dev_warn(dev, "timeout awaiting ars results, continuing...\n");
+			break;
+		} else if (rc == -EBUSY) {
+			mutex_unlock(&acpi_desc->init_mutex);
+			ssleep(1);
+			tmo--;
+			goto retry;
+		}
+
+		/* we got some results, but there are more pending... */
+		if (rc == -ENOSPC && overflow_retry--) {
+			ars_status = acpi_desc->ars_status;
+			/*
+			 * Record the original scrub range, so that we
+			 * can recall all the ranges impacted by the
+			 * initial scrub.
+			 */
+			if (!init_scrub_length) {
+				init_scrub_length = ars_status->length;
+				init_scrub_address = ars_status->address;
+			}
+			rc = ars_continue(acpi_desc);
+			if (rc == 0) {
+				mutex_unlock(&acpi_desc->init_mutex);
+				goto retry;
+			}
+		}
+
+		if (rc < 0) {
+			/*
+			 * Initial scrub failed, we'll give it one more
+			 * try below...
+			 */
+			break;
+		}
+
+		/* We got some final results, record completed ranges */
+		ars_status = acpi_desc->ars_status;
+		if (init_scrub_length) {
+			ars_start = init_scrub_address;
+			ars_len = ars_start + init_scrub_length;
+		} else {
+			ars_start = ars_status->address;
+			ars_len = ars_status->length;
+		}
+		spa = nfit_spa->spa;
+
+		if (!init_ars_done) {
+			init_ars_done = true;
+			dev_dbg(dev, "init scrub %#llx + %#llx complete\n",
+					ars_start, ars_len);
+		}
+		if (ars_start <= spa->address && ars_start + ars_len
+				>= spa->address + spa->length)
+			acpi_nfit_register_region(acpi_desc, nfit_spa);
 	}
+
+	/*
+	 * For all the ranges not covered by an initial scrub we still
+	 * want to see if there are errors, but it's ok to discover them
+	 * asynchronously.
+	 */
+	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
+		/*
+		 * Flag all the ranges that still need scrubbing, but
+		 * register them now to make data available.
+		 */
+		if (nfit_spa->nd_region)
+			nfit_spa->ars_done = 1;
+		else
+			acpi_nfit_register_region(acpi_desc, nfit_spa);
+	}
+
+	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
+		acpi_nfit_async_scrub(acpi_desc, nfit_spa);
+	mutex_unlock(&acpi_desc->init_mutex);
+}
+
+static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
+{
+	struct nfit_spa *nfit_spa;
+	int rc;
+
+	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
+		if (nfit_spa_type(nfit_spa->spa) == NFIT_SPA_DCR) {
+			/* BLK regions don't need to wait for ars results */
+			rc = acpi_nfit_register_region(acpi_desc, nfit_spa);
+			if (rc)
+				return rc;
+		}
+
+	queue_work(nfit_wq, &acpi_desc->work);
 	return 0;
 }
 
@@ -1901,15 +2213,64 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, acpi_size sz)
 }
 EXPORT_SYMBOL_GPL(acpi_nfit_init);
 
-static struct acpi_nfit_desc *acpi_nfit_desc_init(struct acpi_device *adev)
+struct acpi_nfit_flush_work {
+	struct work_struct work;
+	struct completion cmp;
+};
+
+static void flush_probe(struct work_struct *work)
 {
-	struct nvdimm_bus_descriptor *nd_desc;
-	struct acpi_nfit_desc *acpi_desc;
-	struct device *dev = &adev->dev;
+	struct acpi_nfit_flush_work *flush;
 
-	acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
-	if (!acpi_desc)
-		return ERR_PTR(-ENOMEM);
+	flush = container_of(work, typeof(*flush), work);
+	complete(&flush->cmp);
+}
+
+static int acpi_nfit_flush_probe(struct nvdimm_bus_descriptor *nd_desc)
+{
+	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
+	struct device *dev = acpi_desc->dev;
+	struct acpi_nfit_flush_work flush;
+
+	/* bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */
+	device_lock(dev);
+	device_unlock(dev);
+
+	/*
+	 * Scrub work could take 10s of seconds, userspace may give up so we
+	 * need to be interruptible while waiting.
+	 */
+	INIT_WORK_ONSTACK(&flush.work, flush_probe);
+	COMPLETION_INITIALIZER_ONSTACK(flush.cmp);
+	queue_work(nfit_wq, &flush.work);
+	return wait_for_completion_interruptible(&flush.cmp);
+}
+
+static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
+		struct nvdimm *nvdimm, unsigned int cmd)
+{
+	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
+
+	if (nvdimm)
+		return 0;
+	if (cmd != ND_CMD_ARS_START)
+		return 0;
+
+	/*
+	 * The kernel and userspace may race to initiate a scrub, but
+	 * the scrub thread is prepared to lose that initial race.  It
+	 * just needs guarantees that any ars it initiates are not
+	 * interrupted by any intervening start reqeusts from userspace.
+	 */
+	if (work_busy(&acpi_desc->work))
+		return -EBUSY;
+
+	return 0;
+}
+
+void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
+{
+	struct nvdimm_bus_descriptor *nd_desc;
 
 	dev_set_drvdata(dev, acpi_desc);
 	acpi_desc->dev = dev;
@@ -1917,14 +2278,10 @@ static struct acpi_nfit_desc *acpi_nfit_desc_init(struct acpi_device *adev)
 	nd_desc = &acpi_desc->nd_desc;
 	nd_desc->provider_name = "ACPI.NFIT";
 	nd_desc->ndctl = acpi_nfit_ctl;
+	nd_desc->flush_probe = acpi_nfit_flush_probe;
+	nd_desc->clear_to_send = acpi_nfit_clear_to_send;
 	nd_desc->attr_groups = acpi_nfit_attribute_groups;
 
-	acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, nd_desc);
-	if (!acpi_desc->nvdimm_bus) {
-		devm_kfree(dev, acpi_desc);
-		return ERR_PTR(-ENXIO);
-	}
-
 	INIT_LIST_HEAD(&acpi_desc->spa_maps);
 	INIT_LIST_HEAD(&acpi_desc->spas);
 	INIT_LIST_HEAD(&acpi_desc->dcrs);
@@ -1935,9 +2292,9 @@ static struct acpi_nfit_desc *acpi_nfit_desc_init(struct acpi_device *adev)
 	INIT_LIST_HEAD(&acpi_desc->dimms);
 	mutex_init(&acpi_desc->spa_map_mutex);
 	mutex_init(&acpi_desc->init_mutex);
-
-	return acpi_desc;
+	INIT_WORK(&acpi_desc->work, acpi_nfit_scrub);
 }
+EXPORT_SYMBOL_GPL(acpi_nfit_desc_init);
 
 static int acpi_nfit_add(struct acpi_device *adev)
 {
@@ -1956,12 +2313,13 @@ static int acpi_nfit_add(struct acpi_device *adev)
 		return 0;
 	}
 
-	acpi_desc = acpi_nfit_desc_init(adev);
-	if (IS_ERR(acpi_desc)) {
-		dev_err(dev, "%s: error initializing acpi_desc: %ld\n",
-				__func__, PTR_ERR(acpi_desc));
-		return PTR_ERR(acpi_desc);
-	}
+	acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
+	if (!acpi_desc)
+		return -ENOMEM;
+	acpi_nfit_desc_init(acpi_desc, &adev->dev);
+	acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, &acpi_desc->nd_desc);
+	if (!acpi_desc->nvdimm_bus)
+		return -ENOMEM;
 
 	/*
 	 * Save the acpi header for later and then skip it,
@@ -2000,6 +2358,8 @@ static int acpi_nfit_remove(struct acpi_device *adev)
 {
 	struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(&adev->dev);
 
+	acpi_desc->cancel = 1;
+	flush_workqueue(nfit_wq);
 	nvdimm_bus_unregister(acpi_desc->nvdimm_bus);
 	return 0;
 }
@@ -2024,12 +2384,19 @@ static void acpi_nfit_notify(struct acpi_device *adev, u32 event)
 	}
 
 	if (!acpi_desc) {
-		acpi_desc = acpi_nfit_desc_init(adev);
-		if (IS_ERR(acpi_desc)) {
-			dev_err(dev, "%s: error initializing acpi_desc: %ld\n",
-				__func__, PTR_ERR(acpi_desc));
+		acpi_desc = devm_kzalloc(dev, sizeof(*acpi_desc), GFP_KERNEL);
+		if (!acpi_desc)
 			goto out_unlock;
-		}
+		acpi_nfit_desc_init(acpi_desc, &adev->dev);
+		acpi_desc->nvdimm_bus = nvdimm_bus_register(dev, &acpi_desc->nd_desc);
+		if (!acpi_desc->nvdimm_bus)
+			goto out_unlock;
+	} else {
+		/*
+		 * Finish previous registration before considering new
+		 * regions.
+		 */
+		flush_workqueue(nfit_wq);
 	}
 
 	/* Evaluate _FIT */
@@ -2097,12 +2464,17 @@ static __init int nfit_init(void)
 	acpi_str_to_uuid(UUID_NFIT_BUS, nfit_uuid[NFIT_DEV_BUS]);
 	acpi_str_to_uuid(UUID_NFIT_DIMM, nfit_uuid[NFIT_DEV_DIMM]);
 
+	nfit_wq = create_singlethread_workqueue("nfit");
+	if (!nfit_wq)
+		return -ENOMEM;
+
 	return acpi_bus_register_driver(&acpi_nfit_driver);
 }
 
 static __exit void nfit_exit(void)
 {
 	acpi_bus_unregister_driver(&acpi_nfit_driver);
+	destroy_workqueue(nfit_wq);
 }
 
 module_init(nfit_init);
diff --git a/drivers/acpi/nfit.h b/drivers/acpi/nfit.h
index 3d549a383659..c75576b2d50e 100644
--- a/drivers/acpi/nfit.h
+++ b/drivers/acpi/nfit.h
@@ -14,6 +14,7 @@
  */
 #ifndef __NFIT_H__
 #define __NFIT_H__
+#include <linux/workqueue.h>
 #include <linux/libnvdimm.h>
 #include <linux/types.h>
 #include <linux/uuid.h>
@@ -40,15 +41,32 @@ enum nfit_uuids {
 	NFIT_UUID_MAX,
 };
 
+enum nfit_fic {
+	NFIT_FIC_BYTE = 0x101, /* byte-addressable energy backed */
+	NFIT_FIC_BLK = 0x201, /* block-addressable non-energy backed */
+	NFIT_FIC_BYTEN = 0x301, /* byte-addressable non-energy backed */
+};
+
 enum {
-	ND_BLK_READ_FLUSH = 1,
-	ND_BLK_DCR_LATCH = 2,
+	NFIT_BLK_READ_FLUSH = 1,
+	NFIT_BLK_DCR_LATCH = 2,
+	NFIT_ARS_STATUS_DONE = 0,
+	NFIT_ARS_STATUS_BUSY = 1 << 16,
+	NFIT_ARS_STATUS_NONE = 2 << 16,
+	NFIT_ARS_STATUS_INTR = 3 << 16,
+	NFIT_ARS_START_BUSY = 6,
+	NFIT_ARS_CAP_NONE = 1,
+	NFIT_ARS_F_OVERFLOW = 1,
+	NFIT_ARS_TIMEOUT = 90,
 };
 
 struct nfit_spa {
 	struct acpi_nfit_system_address *spa;
 	struct list_head list;
-	int is_registered;
+	struct nd_region *nd_region;
+	unsigned int ars_done:1;
+	u32 clear_err_unit;
+	u32 max_ars;
 };
 
 struct nfit_dcr {
@@ -110,6 +128,10 @@ struct acpi_nfit_desc {
 	struct list_head idts;
 	struct nvdimm_bus *nvdimm_bus;
 	struct device *dev;
+	struct nd_cmd_ars_status *ars_status;
+	size_t ars_status_size;
+	struct work_struct work;
+	unsigned int cancel:1;
 	unsigned long dimm_dsm_force_en;
 	unsigned long bus_dsm_force_en;
 	int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
@@ -182,5 +204,5 @@ static inline struct acpi_nfit_desc *to_acpi_desc(
 
 const u8 *to_nfit_uuid(enum nfit_uuids id);
 int acpi_nfit_init(struct acpi_nfit_desc *nfit, acpi_size sz);
-extern const struct attribute_group *acpi_nfit_attribute_groups[];
+void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev);
 #endif /* __NFIT_H__ */
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index 91a336ea8c4f..e9ff9229d942 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -31,8 +31,6 @@ struct nd_blk_device {
 	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;
@@ -264,7 +262,6 @@ static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
 	}
 
 	disk->driverfs_dev	= &ndns->dev;
-	disk->major		= nd_blk_major;
 	disk->first_minor	= 0;
 	disk->fops		= &nd_blk_fops;
 	disk->private_data	= blk_dev;
@@ -358,25 +355,12 @@ static struct nd_device_driver nd_blk_driver = {
 
 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;
+	return nd_driver_register(&nd_blk_driver);
 }
 
 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>");
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index efb2c1ceef98..c32cbb593600 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -31,8 +31,6 @@ enum log_ent_request {
 	LOG_OLD_ENT
 };
 
-static int btt_major;
-
 static int arena_read_bytes(struct arena_info *arena, resource_size_t offset,
 		void *buf, size_t n)
 {
@@ -1246,7 +1244,6 @@ static int btt_blk_init(struct btt *btt)
 
 	nvdimm_namespace_disk_name(ndns, btt->btt_disk->disk_name);
 	btt->btt_disk->driverfs_dev = &btt->nd_btt->dev;
-	btt->btt_disk->major = btt_major;
 	btt->btt_disk->first_minor = 0;
 	btt->btt_disk->fops = &btt_fops;
 	btt->btt_disk->private_data = btt;
@@ -1423,22 +1420,11 @@ EXPORT_SYMBOL(nvdimm_namespace_detach_btt);
 
 static int __init nd_btt_init(void)
 {
-	int rc;
-
-	btt_major = register_blkdev(0, "btt");
-	if (btt_major < 0)
-		return btt_major;
+	int rc = 0;
 
 	debugfs_root = debugfs_create_dir("btt", NULL);
-	if (IS_ERR_OR_NULL(debugfs_root)) {
+	if (IS_ERR_OR_NULL(debugfs_root))
 		rc = -ENXIO;
-		goto err_debugfs;
-	}
-
-	return 0;
-
- err_debugfs:
-	unregister_blkdev(btt_major, "btt");
 
 	return rc;
 }
@@ -1446,7 +1432,6 @@ static int __init nd_btt_init(void)
 static void __exit nd_btt_exit(void)
 {
 	debugfs_remove_recursive(debugfs_root);
-	unregister_blkdev(btt_major, "btt");
 }
 
 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_BTT);
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 5d28e9405f32..33557481d452 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -133,6 +133,78 @@ static int nvdimm_bus_remove(struct device *dev)
 	return rc;
 }
 
+void nd_device_notify(struct device *dev, enum nvdimm_event event)
+{
+	device_lock(dev);
+	if (dev->driver) {
+		struct nd_device_driver *nd_drv;
+
+		nd_drv = to_nd_device_driver(dev->driver);
+		if (nd_drv->notify)
+			nd_drv->notify(dev, event);
+	}
+	device_unlock(dev);
+}
+EXPORT_SYMBOL(nd_device_notify);
+
+void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event)
+{
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(&nd_region->dev);
+
+	if (!nvdimm_bus)
+		return;
+
+	/* caller is responsible for holding a reference on the device */
+	nd_device_notify(&nd_region->dev, event);
+}
+EXPORT_SYMBOL_GPL(nvdimm_region_notify);
+
+long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
+		unsigned int len)
+{
+	struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+	struct nvdimm_bus_descriptor *nd_desc;
+	struct nd_cmd_clear_error clear_err;
+	struct nd_cmd_ars_cap ars_cap;
+	u32 clear_err_unit, mask;
+	int cmd_rc, rc;
+
+	if (!nvdimm_bus)
+		return -ENXIO;
+
+	nd_desc = nvdimm_bus->nd_desc;
+	if (!nd_desc->ndctl)
+		return -ENXIO;
+
+	memset(&ars_cap, 0, sizeof(ars_cap));
+	ars_cap.address = phys;
+	ars_cap.length = len;
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_CAP, &ars_cap,
+			sizeof(ars_cap), &cmd_rc);
+	if (rc < 0)
+		return rc;
+	if (cmd_rc < 0)
+		return cmd_rc;
+	clear_err_unit = ars_cap.clear_err_unit;
+	if (!clear_err_unit || !is_power_of_2(clear_err_unit))
+		return -ENXIO;
+
+	mask = clear_err_unit - 1;
+	if ((phys | len) & mask)
+		return -ENXIO;
+	memset(&clear_err, 0, sizeof(clear_err));
+	clear_err.address = phys;
+	clear_err.length = len;
+	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_CLEAR_ERROR, &clear_err,
+			sizeof(clear_err), &cmd_rc);
+	if (rc < 0)
+		return rc;
+	if (cmd_rc < 0)
+		return cmd_rc;
+	return clear_err.cleared;
+}
+EXPORT_SYMBOL_GPL(nvdimm_clear_poison);
+
 static struct bus_type nvdimm_bus_type = {
 	.name = "nd",
 	.uevent = nvdimm_bus_uevent,
@@ -395,6 +467,12 @@ static const struct nd_cmd_desc __nd_cmd_bus_descs[] = {
 		.out_num = 3,
 		.out_sizes = { 4, 4, UINT_MAX, },
 	},
+	[ND_CMD_CLEAR_ERROR] = {
+		.in_num = 2,
+		.in_sizes = { 8, 8, },
+		.out_num = 3,
+		.out_sizes = { 4, 4, 8, },
+	},
 };
 
 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd)
@@ -463,17 +541,37 @@ void wait_nvdimm_bus_probe_idle(struct device *dev)
 	} while (true);
 }
 
+static int pmem_active(struct device *dev, void *data)
+{
+	if (is_nd_pmem(dev) && dev->driver)
+		return -EBUSY;
+	return 0;
+}
+
 /* set_config requires an idle interleave set */
-static int nd_cmd_clear_to_send(struct nvdimm *nvdimm, unsigned int cmd)
+static int nd_cmd_clear_to_send(struct nvdimm_bus *nvdimm_bus,
+		struct nvdimm *nvdimm, unsigned int cmd)
 {
-	struct nvdimm_bus *nvdimm_bus;
+	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+
+	/* ask the bus provider if it would like to block this request */
+	if (nd_desc->clear_to_send) {
+		int rc = nd_desc->clear_to_send(nd_desc, nvdimm, cmd);
+
+		if (rc)
+			return rc;
+	}
+
+	/* require clear error to go through the pmem driver */
+	if (!nvdimm && cmd == ND_CMD_CLEAR_ERROR)
+		return device_for_each_child(&nvdimm_bus->dev, NULL,
+				pmem_active);
 
 	if (!nvdimm || cmd != ND_CMD_SET_CONFIG_DATA)
 		return 0;
 
-	nvdimm_bus = walk_to_nvdimm_bus(&nvdimm->dev);
+	/* prevent label manipulation while the kernel owns label updates */
 	wait_nvdimm_bus_probe_idle(&nvdimm_bus->dev);
-
 	if (atomic_read(&nvdimm->busy))
 		return -EBUSY;
 	return 0;
@@ -513,10 +611,11 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 
 	/* fail write commands (when read-only) */
 	if (read_only)
-		switch (ioctl_cmd) {
-		case ND_IOCTL_VENDOR:
-		case ND_IOCTL_SET_CONFIG_DATA:
-		case ND_IOCTL_ARS_START:
+		switch (cmd) {
+		case ND_CMD_VENDOR:
+		case ND_CMD_SET_CONFIG_DATA:
+		case ND_CMD_ARS_START:
+		case ND_CMD_CLEAR_ERROR:
 			dev_dbg(&nvdimm_bus->dev, "'%s' command while read-only.\n",
 					nvdimm ? nvdimm_cmd_name(cmd)
 					: nvdimm_bus_cmd_name(cmd));
@@ -583,11 +682,11 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 	}
 
 	nvdimm_bus_lock(&nvdimm_bus->dev);
-	rc = nd_cmd_clear_to_send(nvdimm, cmd);
+	rc = nd_cmd_clear_to_send(nvdimm_bus, nvdimm, cmd);
 	if (rc)
 		goto out_unlock;
 
-	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len);
+	rc = nd_desc->ndctl(nd_desc, nvdimm, cmd, buf, buf_len, NULL);
 	if (rc < 0)
 		goto out_unlock;
 	if (copy_to_user(p, buf, buf_len))
@@ -602,14 +701,14 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 static long nd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	long id = (long) file->private_data;
-	int rc = -ENXIO, read_only;
+	int rc = -ENXIO, ro;
 	struct nvdimm_bus *nvdimm_bus;
 
-	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
+	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 		if (nvdimm_bus->id == id) {
-			rc = __nd_ioctl(nvdimm_bus, NULL, read_only, cmd, arg);
+			rc = __nd_ioctl(nvdimm_bus, NULL, ro, cmd, arg);
 			break;
 		}
 	}
@@ -633,10 +732,10 @@ static int match_dimm(struct device *dev, void *data)
 
 static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	int rc = -ENXIO, read_only;
+	int rc = -ENXIO, ro;
 	struct nvdimm_bus *nvdimm_bus;
 
-	read_only = (O_RDWR != (file->f_flags & O_ACCMODE));
+	ro = ((file->f_flags & O_ACCMODE) == O_RDONLY);
 	mutex_lock(&nvdimm_bus_list_mutex);
 	list_for_each_entry(nvdimm_bus, &nvdimm_bus_list, list) {
 		struct device *dev = device_find_child(&nvdimm_bus->dev,
@@ -647,7 +746,7 @@ static long nvdimm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			continue;
 
 		nvdimm = to_nvdimm(dev);
-		rc = __nd_ioctl(nvdimm_bus, nvdimm, read_only, cmd, arg);
+		rc = __nd_ioctl(nvdimm_bus, nvdimm, ro, cmd, arg);
 		put_device(dev);
 		break;
 	}
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 2e2832b83c93..79646d0c3277 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -298,6 +298,15 @@ static int flush_regions_dimms(struct device *dev, void *data)
 static ssize_t wait_probe_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
+	struct nvdimm_bus *nvdimm_bus = to_nvdimm_bus(dev);
+	struct nvdimm_bus_descriptor *nd_desc = nvdimm_bus->nd_desc;
+	int rc;
+
+	if (nd_desc->flush_probe) {
+		rc = nd_desc->flush_probe(nd_desc);
+		if (rc)
+			return rc;
+	}
 	nd_synchronize();
 	device_for_each_child(dev, NULL, flush_regions_dimms);
 	return sprintf(buf, "1\n");
@@ -408,33 +417,11 @@ static void __add_badblock_range(struct badblocks *bb, u64 ns_offset, u64 len)
 		set_badblock(bb, start_sector, num_sectors);
 }
 
-/**
- * nvdimm_namespace_add_poison() - Convert a list of poison ranges to badblocks
- * @ndns:	the namespace containing poison ranges
- * @bb:		badblocks instance to populate
- * @offset:	offset at the start of the namespace before 'sector 0'
- *
- * The poison list generated during NFIT initialization may contain multiple,
- * possibly overlapping ranges in the SPA (System Physical Address) space.
- * Compare each of these ranges to the namespace currently being initialized,
- * and add badblocks to the gendisk for all matching sub-ranges
- */
-void nvdimm_namespace_add_poison(struct nd_namespace_common *ndns,
-		struct badblocks *bb, resource_size_t offset)
+static void namespace_add_poison(struct list_head *poison_list,
+		struct badblocks *bb, struct resource *res)
 {
-	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
-	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
-	struct nvdimm_bus *nvdimm_bus;
-	struct list_head *poison_list;
-	u64 ns_start, ns_end, ns_size;
 	struct nd_poison *pl;
 
-	ns_size = nvdimm_namespace_capacity(ndns) - offset;
-	ns_start = nsio->res.start + offset;
-	ns_end = nsio->res.end;
-
-	nvdimm_bus = to_nvdimm_bus(nd_region->dev.parent);
-	poison_list = &nvdimm_bus->poison_list;
 	if (list_empty(poison_list))
 		return;
 
@@ -442,37 +429,69 @@ void nvdimm_namespace_add_poison(struct nd_namespace_common *ndns,
 		u64 pl_end = pl->start + pl->length - 1;
 
 		/* Discard intervals with no intersection */
-		if (pl_end < ns_start)
+		if (pl_end < res->start)
 			continue;
-		if (pl->start > ns_end)
+		if (pl->start >  res->end)
 			continue;
 		/* Deal with any overlap after start of the namespace */
-		if (pl->start >= ns_start) {
+		if (pl->start >= res->start) {
 			u64 start = pl->start;
 			u64 len;
 
-			if (pl_end <= ns_end)
+			if (pl_end <= res->end)
 				len = pl->length;
 			else
-				len = ns_start + ns_size - pl->start;
-			__add_badblock_range(bb, start - ns_start, len);
+				len = res->start + resource_size(res)
+					- pl->start;
+			__add_badblock_range(bb, start - res->start, len);
 			continue;
 		}
 		/* Deal with overlap for poison starting before the namespace */
-		if (pl->start < ns_start) {
+		if (pl->start < res->start) {
 			u64 len;
 
-			if (pl_end < ns_end)
-				len = pl->start + pl->length - ns_start;
+			if (pl_end < res->end)
+				len = pl->start + pl->length - res->start;
 			else
-				len = ns_size;
+				len = resource_size(res);
 			__add_badblock_range(bb, 0, len);
 		}
 	}
 }
+
+/**
+ * nvdimm_namespace_add_poison() - Convert a list of poison ranges to badblocks
+ * @ndns:	the namespace containing poison ranges
+ * @bb:		badblocks instance to populate
+ * @offset:	offset at the start of the namespace before 'sector 0'
+ *
+ * The poison list generated during NFIT initialization may contain multiple,
+ * possibly overlapping ranges in the SPA (System Physical Address) space.
+ * Compare each of these ranges to the namespace currently being initialized,
+ * and add badblocks to the gendisk for all matching sub-ranges
+ */
+void nvdimm_namespace_add_poison(struct nd_namespace_common *ndns,
+		struct badblocks *bb, resource_size_t offset)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
+	struct nvdimm_bus *nvdimm_bus;
+	struct list_head *poison_list;
+	struct resource res = {
+		.start = nsio->res.start + offset,
+		.end = nsio->res.end,
+	};
+
+	nvdimm_bus = to_nvdimm_bus(nd_region->dev.parent);
+	poison_list = &nvdimm_bus->poison_list;
+
+	nvdimm_bus_lock(&nvdimm_bus->dev);
+	namespace_add_poison(poison_list, bb, &res);
+	nvdimm_bus_unlock(&nvdimm_bus->dev);
+}
 EXPORT_SYMBOL_GPL(nvdimm_namespace_add_poison);
 
-static int __add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
+static int add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 {
 	struct nd_poison *pl;
 
@@ -487,12 +506,12 @@ static int __add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 	return 0;
 }
 
-int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
+static int bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 {
 	struct nd_poison *pl;
 
 	if (list_empty(&nvdimm_bus->poison_list))
-		return __add_poison(nvdimm_bus, addr, length);
+		return add_poison(nvdimm_bus, addr, length);
 
 	/*
 	 * There is a chance this is a duplicate, check for those first.
@@ -512,7 +531,18 @@ int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
 	 * as any overlapping ranges will get resolved when the list is consumed
 	 * and converted to badblocks
 	 */
-	return __add_poison(nvdimm_bus, addr, length);
+	return add_poison(nvdimm_bus, addr, length);
+}
+
+int nvdimm_bus_add_poison(struct nvdimm_bus *nvdimm_bus, u64 addr, u64 length)
+{
+	int rc;
+
+	nvdimm_bus_lock(&nvdimm_bus->dev);
+	rc = bus_add_poison(nvdimm_bus, addr, length);
+	nvdimm_bus_unlock(&nvdimm_bus->dev);
+
+	return rc;
 }
 EXPORT_SYMBOL_GPL(nvdimm_bus_add_poison);
 
@@ -553,7 +583,11 @@ void nvdimm_bus_unregister(struct nvdimm_bus *nvdimm_bus)
 
 	nd_synchronize();
 	device_for_each_child(&nvdimm_bus->dev, NULL, child_unregister);
+
+	nvdimm_bus_lock(&nvdimm_bus->dev);
 	free_poison_list(&nvdimm_bus->poison_list);
+	nvdimm_bus_unlock(&nvdimm_bus->dev);
+
 	nvdimm_bus_destroy_ndctl(nvdimm_bus);
 
 	device_unregister(&nvdimm_bus->dev);
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 651b8d19d324..c56f88217924 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -75,7 +75,7 @@ int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd)
 	memset(cmd, 0, sizeof(*cmd));
 	nd_desc = nvdimm_bus->nd_desc;
 	return nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
-			ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd));
+			ND_CMD_GET_CONFIG_SIZE, cmd, sizeof(*cmd), NULL);
 }
 
 int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
@@ -120,7 +120,7 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
 		cmd->in_offset = offset;
 		rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
 				ND_CMD_GET_CONFIG_DATA, cmd,
-				cmd->in_length + sizeof(*cmd));
+				cmd->in_length + sizeof(*cmd), NULL);
 		if (rc || cmd->status) {
 			rc = -ENXIO;
 			break;
@@ -171,7 +171,7 @@ int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
 		status = ((void *) cmd) + cmd_size - sizeof(u32);
 
 		rc = nd_desc->ndctl(nd_desc, to_nvdimm(ndd->dev),
-				ND_CMD_SET_CONFIG_DATA, cmd, cmd_size);
+				ND_CMD_SET_CONFIG_DATA, cmd, cmd_size, NULL);
 		if (rc || *status) {
 			rc = rc ? rc : -ENXIO;
 			break;
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 9edf7eb7d17c..f5cb88601359 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -133,6 +133,7 @@ bool nd_is_uuid_unique(struct device *dev, u8 *uuid)
 bool pmem_should_map_pages(struct device *dev)
 {
 	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct nd_namespace_io *nsio;
 
 	if (!IS_ENABLED(CONFIG_ZONE_DEVICE))
 		return false;
@@ -143,6 +144,12 @@ bool pmem_should_map_pages(struct device *dev)
 	if (is_nd_pfn(dev) || is_nd_btt(dev))
 		return false;
 
+	nsio = to_nd_namespace_io(dev);
+	if (region_intersects(nsio->res.start, resource_size(&nsio->res),
+				IORESOURCE_SYSTEM_RAM,
+				IORES_DESC_NONE) == REGION_MIXED)
+		return false;
+
 #ifdef ARCH_MEMREMAP_PMEM
 	return ARCH_MEMREMAP_PMEM == MEMREMAP_WB;
 #else
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index ba1633b9da31..1799bd97a9ce 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -18,6 +18,7 @@
 #include <linux/mutex.h>
 #include <linux/ndctl.h>
 #include <linux/types.h>
+#include <linux/nd.h>
 #include "label.h"
 
 enum {
@@ -168,6 +169,7 @@ int nd_integrity_init(struct gendisk *disk, unsigned long meta_size);
 void wait_nvdimm_bus_probe_idle(struct device *dev);
 void nd_device_register(struct device *dev);
 void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
+void nd_device_notify(struct device *dev, enum nvdimm_event event);
 int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
 		size_t len);
 ssize_t nd_sector_size_show(unsigned long current_lbasize,
@@ -184,6 +186,8 @@ int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
 int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
 int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,
 		void *buf, size_t len);
+long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
+		unsigned int len);
 struct nd_btt *to_nd_btt(struct device *dev);
 
 struct nd_gen_sb {
diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index cc243754acef..8e343a3ca873 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -15,6 +15,7 @@
 #define __NVDIMM_PFN_H
 
 #include <linux/types.h>
+#include <linux/mmzone.h>
 
 #define PFN_SIG_LEN 16
 #define PFN_SIG "NVDIMM_PFN_INFO\0"
@@ -26,10 +27,28 @@ struct nd_pfn_sb {
 	__le32 flags;
 	__le16 version_major;
 	__le16 version_minor;
-	__le64 dataoff;
+	__le64 dataoff; /* relative to namespace_base + start_pad */
 	__le64 npfns;
 	__le32 mode;
-	u8 padding[4012];
+	/* minor-version-1 additions for section alignment */
+	__le32 start_pad;
+	__le32 end_trunc;
+	u8 padding[4004];
 	__le64 checksum;
 };
+
+#ifdef CONFIG_SPARSEMEM
+#define PFN_SECTION_ALIGN_DOWN(x) SECTION_ALIGN_DOWN(x)
+#define PFN_SECTION_ALIGN_UP(x) SECTION_ALIGN_UP(x)
+#else
+/*
+ * In this case ZONE_DEVICE=n and we will disable 'pfn' device support,
+ * but we still want pmem to compile.
+ */
+#define PFN_SECTION_ALIGN_DOWN(x) (x)
+#define PFN_SECTION_ALIGN_UP(x) (x)
+#endif
+
+#define PHYS_SECTION_ALIGN_DOWN(x) PFN_PHYS(PFN_SECTION_ALIGN_DOWN(PHYS_PFN(x)))
+#define PHYS_SECTION_ALIGN_UP(x) PFN_PHYS(PFN_SECTION_ALIGN_UP(PHYS_PFN(x)))
 #endif /* __NVDIMM_PFN_H */
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index ae81a2f1da50..254d3bc13f70 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -205,11 +205,67 @@ static ssize_t namespace_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(namespace);
 
+static ssize_t resource_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	if (dev->driver) {
+		struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+		u64 offset = __le64_to_cpu(pfn_sb->dataoff);
+		struct nd_namespace_common *ndns = nd_pfn->ndns;
+		u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+		struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+
+		rc = sprintf(buf, "%#llx\n", (unsigned long long) nsio->res.start
+				+ start_pad + offset);
+	} else {
+		/* no address to convey if the pfn instance is disabled */
+		rc = -ENXIO;
+	}
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(resource);
+
+static ssize_t size_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+	ssize_t rc;
+
+	device_lock(dev);
+	if (dev->driver) {
+		struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+		u64 offset = __le64_to_cpu(pfn_sb->dataoff);
+		struct nd_namespace_common *ndns = nd_pfn->ndns;
+		u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+		u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+		struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+
+		rc = sprintf(buf, "%llu\n", (unsigned long long)
+				resource_size(&nsio->res) - start_pad
+				- end_trunc - offset);
+	} else {
+		/* no size to convey if the pfn instance is disabled */
+		rc = -ENXIO;
+	}
+	device_unlock(dev);
+
+	return rc;
+}
+static DEVICE_ATTR_RO(size);
+
 static struct attribute *nd_pfn_attributes[] = {
 	&dev_attr_mode.attr,
 	&dev_attr_namespace.attr,
 	&dev_attr_uuid.attr,
 	&dev_attr_align.attr,
+	&dev_attr_resource.attr,
+	&dev_attr_size.attr,
 	NULL,
 };
 
@@ -299,6 +355,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 	if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
 		return -ENODEV;
 
+	if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
+		pfn_sb->start_pad = 0;
+		pfn_sb->end_trunc = 0;
+	}
+
 	switch (le32_to_cpu(pfn_sb->mode)) {
 	case PFN_MODE_RAM:
 	case PFN_MODE_PMEM:
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 8d0b54670184..ca5721c306bb 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -43,12 +43,13 @@ struct pmem_device {
 	phys_addr_t		data_offset;
 	u64			pfn_flags;
 	void __pmem		*virt_addr;
+	/* immutable base size of the namespace */
 	size_t			size;
+	/* trim size when namespace capacity has been section aligned */
+	u32			pfn_pad;
 	struct badblocks	bb;
 };
 
-static int pmem_major;
-
 static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
 {
 	if (bb->count) {
@@ -62,26 +63,56 @@ static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
 	return false;
 }
 
+static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
+		unsigned int len)
+{
+	struct device *dev = disk_to_dev(pmem->pmem_disk);
+	sector_t sector;
+	long cleared;
+
+	sector = (offset - pmem->data_offset) / 512;
+	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
+
+	if (cleared > 0 && cleared / 512) {
+		dev_dbg(dev, "%s: %llx clear %ld sector%s\n",
+				__func__, (unsigned long long) sector,
+				cleared / 512, cleared / 512 > 1 ? "s" : "");
+		badblocks_clear(&pmem->bb, sector, cleared / 512);
+	}
+	invalidate_pmem(pmem->virt_addr + offset, len);
+}
+
 static int pmem_do_bvec(struct pmem_device *pmem, struct page *page,
 			unsigned int len, unsigned int off, int rw,
 			sector_t sector)
 {
+	int rc = 0;
+	bool bad_pmem = false;
 	void *mem = kmap_atomic(page);
 	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
 	void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
 
+	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
+		bad_pmem = true;
+
 	if (rw == READ) {
-		if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
-			return -EIO;
-		memcpy_from_pmem(mem + off, pmem_addr, len);
-		flush_dcache_page(page);
+		if (unlikely(bad_pmem))
+			rc = -EIO;
+		else {
+			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);
+		if (unlikely(bad_pmem)) {
+			pmem_clear_poison(pmem, pmem_off, len);
+			memcpy_to_pmem(pmem_addr, mem + off, len);
+		}
 	}
 
 	kunmap_atomic(mem);
-	return 0;
+	return rc;
 }
 
 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
@@ -145,7 +176,7 @@ static long pmem_direct_access(struct block_device *bdev, sector_t sector,
 	*kaddr = pmem->virt_addr + offset;
 	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
 
-	return pmem->size - offset;
+	return pmem->size - pmem->pfn_pad - offset;
 }
 
 static const struct block_device_operations pmem_fops = {
@@ -228,15 +259,14 @@ static int pmem_attach_disk(struct device *dev,
 		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 = dev;
-	set_capacity(disk, (pmem->size - pmem->data_offset) / 512);
+	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
+			/ 512);
 	pmem->pmem_disk = disk;
 	devm_exit_badblocks(dev, &pmem->bb);
 	if (devm_init_badblocks(dev, &pmem->bb))
@@ -279,6 +309,9 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
 	struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
 	struct nd_namespace_common *ndns = nd_pfn->ndns;
+	u32 start_pad = 0, end_trunc = 0;
+	resource_size_t start, size;
+	struct nd_namespace_io *nsio;
 	struct nd_region *nd_region;
 	unsigned long npfns;
 	phys_addr_t offset;
@@ -304,21 +337,56 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	}
 
 	memset(pfn_sb, 0, sizeof(*pfn_sb));
-	npfns = (pmem->size - SZ_8K) / SZ_4K;
+
+	/*
+	 * Check if pmem collides with 'System RAM' when section aligned and
+	 * trim it accordingly
+	 */
+	nsio = to_nd_namespace_io(&ndns->dev);
+	start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
+	size = resource_size(&nsio->res);
+	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
+				IORES_DESC_NONE) == REGION_MIXED) {
+
+		start = nsio->res.start;
+		start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
+	}
+
+	start = nsio->res.start;
+	size = PHYS_SECTION_ALIGN_UP(start + size) - start;
+	if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
+				IORES_DESC_NONE) == REGION_MIXED) {
+		size = resource_size(&nsio->res);
+		end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
+	}
+
+	if (start_pad + end_trunc)
+		dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
+				dev_name(&ndns->dev), start_pad + end_trunc);
+
 	/*
 	 * Note, we use 64 here for the standard size of struct page,
 	 * debugging options may cause it to be larger in which case the
 	 * implementation will limit the pfns advertised through
 	 * ->direct_access() to those that are included in the memmap.
 	 */
+	start += start_pad;
+	npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
 	if (nd_pfn->mode == PFN_MODE_PMEM)
-		offset = ALIGN(SZ_8K + 64 * npfns, nd_pfn->align);
+		offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
+			- start;
 	else if (nd_pfn->mode == PFN_MODE_RAM)
-		offset = ALIGN(SZ_8K, nd_pfn->align);
+		offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
 	else
 		goto err;
 
-	npfns = (pmem->size - offset) / SZ_4K;
+	if (offset + start_pad + end_trunc >= pmem->size) {
+		dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
+				dev_name(&ndns->dev));
+		goto err;
+	}
+
+	npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
 	pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
 	pfn_sb->dataoff = cpu_to_le64(offset);
 	pfn_sb->npfns = cpu_to_le64(npfns);
@@ -326,6 +394,9 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 	memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
 	memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
 	pfn_sb->version_major = cpu_to_le16(1);
+	pfn_sb->version_minor = cpu_to_le16(1);
+	pfn_sb->start_pad = cpu_to_le32(start_pad);
+	pfn_sb->end_trunc = cpu_to_le32(end_trunc);
 	checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
 	pfn_sb->checksum = cpu_to_le64(checksum);
 
@@ -356,41 +427,56 @@ static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
 	return 0;
 }
 
-static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
+/*
+ * We hotplug memory at section granularity, pad the reserved area from
+ * the previous section base to the namespace base address.
+ */
+static unsigned long init_altmap_base(resource_size_t base)
+{
+	unsigned long base_pfn = PHYS_PFN(base);
+
+	return PFN_SECTION_ALIGN_DOWN(base_pfn);
+}
+
+static unsigned long init_altmap_reserve(resource_size_t base)
+{
+	unsigned long reserve = PHYS_PFN(SZ_8K);
+	unsigned long base_pfn = PHYS_PFN(base);
+
+	reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
+	return reserve;
+}
+
+static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
 {
-	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
-	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
-	struct device *dev = &nd_pfn->dev;
-	struct nd_region *nd_region;
-	struct vmem_altmap *altmap;
-	struct nd_pfn_sb *pfn_sb;
-	struct pmem_device *pmem;
-	struct request_queue *q;
-	phys_addr_t offset;
 	int rc;
+	struct resource res;
+	struct request_queue *q;
+	struct pmem_device *pmem;
+	struct vmem_altmap *altmap;
+	struct device *dev = &nd_pfn->dev;
+	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+	struct nd_namespace_common *ndns = nd_pfn->ndns;
+	u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+	u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	resource_size_t base = nsio->res.start + start_pad;
 	struct vmem_altmap __altmap = {
-		.base_pfn = __phys_to_pfn(nsio->res.start),
-		.reserve = __phys_to_pfn(SZ_8K),
+		.base_pfn = init_altmap_base(base),
+		.reserve = init_altmap_reserve(base),
 	};
 
-	if (!nd_pfn->uuid || !nd_pfn->ndns)
-		return -ENODEV;
-
-	nd_region = to_nd_region(dev->parent);
-	rc = nd_pfn_init(nd_pfn);
-	if (rc)
-		return rc;
-
-	pfn_sb = nd_pfn->pfn_sb;
-	offset = le64_to_cpu(pfn_sb->dataoff);
+	pmem = dev_get_drvdata(dev);
+	pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
+	pmem->pfn_pad = start_pad + end_trunc;
 	nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
 	if (nd_pfn->mode == PFN_MODE_RAM) {
-		if (offset < SZ_8K)
+		if (pmem->data_offset < SZ_8K)
 			return -EINVAL;
 		nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
 		altmap = NULL;
 	} else if (nd_pfn->mode == PFN_MODE_PMEM) {
-		nd_pfn->npfns = (resource_size(&nsio->res) - offset)
+		nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
 			/ PAGE_SIZE;
 		if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
 			dev_info(&nd_pfn->dev,
@@ -398,7 +484,7 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 					le64_to_cpu(nd_pfn->pfn_sb->npfns),
 					nd_pfn->npfns);
 		altmap = & __altmap;
-		altmap->free = __phys_to_pfn(offset - SZ_8K);
+		altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
 		altmap->alloc = 0;
 	} else {
 		rc = -ENXIO;
@@ -406,10 +492,12 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 	}
 
 	/* establish pfn range for lookup, and switch to direct map */
-	pmem = dev_get_drvdata(dev);
 	q = pmem->pmem_queue;
+	memcpy(&res, &nsio->res, sizeof(res));
+	res.start += start_pad;
+	res.end -= end_trunc;
 	devm_memunmap(dev, (void __force *) pmem->virt_addr);
-	pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &nsio->res,
+	pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
 			&q->q_usage_counter, altmap);
 	pmem->pfn_flags |= PFN_MAP;
 	if (IS_ERR(pmem->virt_addr)) {
@@ -418,7 +506,6 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
 	}
 
 	/* attach pmem disk in "pfn-mode" */
-	pmem->data_offset = offset;
 	rc = pmem_attach_disk(dev, ndns, pmem);
 	if (rc)
 		goto err;
@@ -427,6 +514,22 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
  err:
 	nvdimm_namespace_detach_pfn(ndns);
 	return rc;
+
+}
+
+static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
+{
+	struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+	int rc;
+
+	if (!nd_pfn->uuid || !nd_pfn->ndns)
+		return -ENODEV;
+
+	rc = nd_pfn_init(nd_pfn);
+	if (rc)
+		return rc;
+	/* we need a valid pfn_sb before we can init a vmem_altmap */
+	return __nvdimm_namespace_attach_pfn(nd_pfn);
 }
 
 static int nd_pmem_probe(struct device *dev)
@@ -488,12 +591,27 @@ static int nd_pmem_remove(struct device *dev)
 	return 0;
 }
 
+static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
+{
+	struct pmem_device *pmem = dev_get_drvdata(dev);
+	struct nd_namespace_common *ndns = pmem->ndns;
+
+	if (event != NVDIMM_REVALIDATE_POISON)
+		return;
+
+	if (is_nd_btt(dev))
+		nvdimm_namespace_add_poison(ndns, &pmem->bb, 0);
+	else
+		nvdimm_namespace_add_poison(ndns, &pmem->bb, pmem->data_offset);
+}
+
 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,
+	.notify = nd_pmem_notify,
 	.drv = {
 		.name = "nd_pmem",
 	},
@@ -502,26 +620,13 @@ static struct nd_device_driver nd_pmem_driver = {
 
 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;
+	return nd_driver_register(&nd_pmem_driver);
 }
 module_init(pmem_init);
 
 static void pmem_exit(void)
 {
 	driver_unregister(&nd_pmem_driver.drv);
-	unregister_blkdev(pmem_major, "pmem");
 }
 module_exit(pmem_exit);
 
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
index 7da63eac78ee..4b7715e29cff 100644
--- a/drivers/nvdimm/region.c
+++ b/drivers/nvdimm/region.c
@@ -93,9 +93,21 @@ static int nd_region_remove(struct device *dev)
 	return 0;
 }
 
+static int child_notify(struct device *dev, void *data)
+{
+	nd_device_notify(dev, *(enum nvdimm_event *) data);
+	return 0;
+}
+
+static void nd_region_notify(struct device *dev, enum nvdimm_event event)
+{
+	device_for_each_child(dev, &event, child_notify);
+}
+
 static struct nd_device_driver nd_region_driver = {
 	.probe = nd_region_probe,
 	.remove = nd_region_remove,
+	.notify = nd_region_notify,
 	.drv = {
 		.name = "nd_region",
 	},
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index 212a8e69d7c0..0b65543dc6cf 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -172,6 +172,7 @@ extern void reserve_region_with_split(struct resource *root,
 extern struct resource *insert_resource_conflict(struct resource *parent, struct resource *new);
 extern int insert_resource(struct resource *parent, struct resource *new);
 extern void insert_resource_expand_to_fit(struct resource *root, struct resource *new);
+extern int remove_resource(struct resource *old);
 extern void arch_remove_reservations(struct resource *avail);
 extern int allocate_resource(struct resource *root, struct resource *new,
 			     resource_size_t size, resource_size_t min,
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 141ffdd59960..833867b9ddc2 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -48,7 +48,7 @@ struct nvdimm;
 struct nvdimm_bus_descriptor;
 typedef int (*ndctl_fn)(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd, void *buf,
-		unsigned int buf_len);
+		unsigned int buf_len, int *cmd_rc);
 
 struct nd_namespace_label;
 struct nvdimm_drvdata;
@@ -71,6 +71,9 @@ struct nvdimm_bus_descriptor {
 	unsigned long dsm_mask;
 	char *provider_name;
 	ndctl_fn ndctl;
+	int (*flush_probe)(struct nvdimm_bus_descriptor *nd_desc);
+	int (*clear_to_send)(struct nvdimm_bus_descriptor *nd_desc,
+			struct nvdimm *nvdimm, unsigned int cmd);
 };
 
 struct nd_cmd_desc {
diff --git a/include/linux/nd.h b/include/linux/nd.h
index 507e47c86737..5489ab756d1a 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -16,11 +16,16 @@
 #include <linux/ndctl.h>
 #include <linux/device.h>
 
+enum nvdimm_event {
+	NVDIMM_REVALIDATE_POISON,
+};
+
 struct nd_device_driver {
 	struct device_driver drv;
 	unsigned long type;
 	int (*probe)(struct device *dev);
 	int (*remove)(struct device *dev);
+	void (*notify)(struct device *dev, enum nvdimm_event event);
 };
 
 static inline struct nd_device_driver *to_nd_device_driver(
@@ -144,6 +149,8 @@ static inline int nvdimm_write_bytes(struct nd_namespace_common *ndns,
 	MODULE_ALIAS("nd:t" __stringify(type) "*")
 #define ND_DEVICE_MODALIAS_FMT "nd:t%d"
 
+struct nd_region;
+void nvdimm_region_notify(struct nd_region *nd_region, enum nvdimm_event event);
 int __must_check __nd_driver_register(struct nd_device_driver *nd_drv,
 		struct module *module, const char *mod_name);
 #define nd_driver_register(driver) \
diff --git a/include/linux/pmem.h b/include/linux/pmem.h
index 7c3d11a6b4ad..3ec5309e29f3 100644
--- a/include/linux/pmem.h
+++ b/include/linux/pmem.h
@@ -58,6 +58,11 @@ static inline void arch_wb_cache_pmem(void __pmem *addr, size_t size)
 {
 	BUG();
 }
+
+static inline void arch_invalidate_pmem(void __pmem *addr, size_t size)
+{
+	BUG();
+}
 #endif
 
 /*
@@ -186,6 +191,20 @@ static inline void clear_pmem(void __pmem *addr, size_t size)
 }
 
 /**
+ * invalidate_pmem - flush a pmem range from the cache hierarchy
+ * @addr:	virtual start address
+ * @size:	bytes to invalidate (internally aligned to cache line size)
+ *
+ * For platforms that support clearing poison this flushes any poisoned
+ * ranges out of the cache
+ */
+static inline void invalidate_pmem(void __pmem *addr, size_t size)
+{
+	if (arch_has_pmem_api())
+		arch_invalidate_pmem(addr, size);
+}
+
+/**
  * wb_cache_pmem - write back processor cache for PMEM memory range
  * @addr:	virtual start address
  * @size:	number of bytes to write back
diff --git a/include/uapi/linux/ndctl.h b/include/uapi/linux/ndctl.h
index cc68b92124d4..7cc28ab05b87 100644
--- a/include/uapi/linux/ndctl.h
+++ b/include/uapi/linux/ndctl.h
@@ -98,6 +98,14 @@ struct nd_cmd_ars_status {
 	} __packed records[0];
 } __packed;
 
+struct nd_cmd_clear_error {
+	__u64 address;
+	__u64 length;
+	__u32 status;
+	__u8 reserved[4];
+	__u64 cleared;
+} __packed;
+
 enum {
 	ND_CMD_IMPLEMENTED = 0,
 
@@ -105,6 +113,7 @@ enum {
 	ND_CMD_ARS_CAP = 1,
 	ND_CMD_ARS_START = 2,
 	ND_CMD_ARS_STATUS = 3,
+	ND_CMD_CLEAR_ERROR = 4,
 
 	/* per-dimm commands */
 	ND_CMD_SMART = 1,
@@ -129,6 +138,7 @@ static inline const char *nvdimm_bus_cmd_name(unsigned cmd)
 		[ND_CMD_ARS_CAP] = "ars_cap",
 		[ND_CMD_ARS_START] = "ars_start",
 		[ND_CMD_ARS_STATUS] = "ars_status",
+		[ND_CMD_CLEAR_ERROR] = "clear_error",
 	};
 
 	if (cmd < ARRAY_SIZE(names) && names[cmd])
@@ -187,6 +197,9 @@ static inline const char *nvdimm_cmd_name(unsigned cmd)
 #define ND_IOCTL_ARS_STATUS		_IOWR(ND_IOCTL, ND_CMD_ARS_STATUS,\
 					struct nd_cmd_ars_status)
 
+#define ND_IOCTL_CLEAR_ERROR		_IOWR(ND_IOCTL, ND_CMD_CLEAR_ERROR,\
+					struct nd_cmd_clear_error)
+
 #define ND_DEVICE_DIMM 1            /* nd_dimm: container for "config data" */
 #define ND_DEVICE_REGION_PMEM 2     /* nd_region: (parent of PMEM namespaces) */
 #define ND_DEVICE_REGION_BLK 3      /* nd_region: (parent of BLK namespaces) */
diff --git a/kernel/resource.c b/kernel/resource.c
index 4d466052426b..2e78ead30934 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -233,9 +233,9 @@ static struct resource * __request_resource(struct resource *root, struct resour
 	}
 }
 
-static int __release_resource(struct resource *old)
+static int __release_resource(struct resource *old, bool release_child)
 {
-	struct resource *tmp, **p;
+	struct resource *tmp, **p, *chd;
 
 	p = &old->parent->child;
 	for (;;) {
@@ -243,7 +243,17 @@ static int __release_resource(struct resource *old)
 		if (!tmp)
 			break;
 		if (tmp == old) {
-			*p = tmp->sibling;
+			if (release_child || !(tmp->child)) {
+				*p = tmp->sibling;
+			} else {
+				for (chd = tmp->child;; chd = chd->sibling) {
+					chd->parent = tmp->parent;
+					if (!(chd->sibling))
+						break;
+				}
+				*p = tmp->child;
+				chd->sibling = tmp->sibling;
+			}
 			old->parent = NULL;
 			return 0;
 		}
@@ -325,7 +335,7 @@ int release_resource(struct resource *old)
 	int retval;
 
 	write_lock(&resource_lock);
-	retval = __release_resource(old);
+	retval = __release_resource(old, true);
 	write_unlock(&resource_lock);
 	return retval;
 }
@@ -679,7 +689,7 @@ static int reallocate_resource(struct resource *root, struct resource *old,
 		old->start = new.start;
 		old->end = new.end;
 	} else {
-		__release_resource(old);
+		__release_resource(old, true);
 		*old = new;
 		conflict = __request_resource(root, old);
 		BUG_ON(conflict);
@@ -825,6 +835,9 @@ static struct resource * __insert_resource(struct resource *parent, struct resou
  * entirely fit within the range of the new resource, then the new
  * resource is inserted and the conflicting resources become children of
  * the new resource.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
  */
 struct resource *insert_resource_conflict(struct resource *parent, struct resource *new)
 {
@@ -842,6 +855,9 @@ struct resource *insert_resource_conflict(struct resource *parent, struct resour
  * @new: new resource to insert
  *
  * Returns 0 on success, -EBUSY if the resource can't be inserted.
+ *
+ * This function is intended for producers of resources, such as FW modules
+ * and bus drivers.
  */
 int insert_resource(struct resource *parent, struct resource *new)
 {
@@ -850,6 +866,7 @@ int insert_resource(struct resource *parent, struct resource *new)
 	conflict = insert_resource_conflict(parent, new);
 	return conflict ? -EBUSY : 0;
 }
+EXPORT_SYMBOL_GPL(insert_resource);
 
 /**
  * insert_resource_expand_to_fit - Insert a resource into the resource tree
@@ -885,6 +902,32 @@ void insert_resource_expand_to_fit(struct resource *root, struct resource *new)
 	write_unlock(&resource_lock);
 }
 
+/**
+ * remove_resource - Remove a resource in the resource tree
+ * @old: resource to remove
+ *
+ * Returns 0 on success, -EINVAL if the resource is not valid.
+ *
+ * This function removes a resource previously inserted by insert_resource()
+ * or insert_resource_conflict(), and moves the children (if any) up to
+ * where they were before.  insert_resource() and insert_resource_conflict()
+ * insert a new resource, and move any conflicting resources down to the
+ * children of the new resource.
+ *
+ * insert_resource(), insert_resource_conflict() and remove_resource() are
+ * intended for producers of resources, such as FW modules and bus drivers.
+ */
+int remove_resource(struct resource *old)
+{
+	int retval;
+
+	write_lock(&resource_lock);
+	retval = __release_resource(old, false);
+	write_unlock(&resource_lock);
+	return retval;
+}
+EXPORT_SYMBOL_GPL(remove_resource);
+
 static int __adjust_resource(struct resource *res, resource_size_t start,
 				resource_size_t size)
 {
@@ -1085,15 +1128,16 @@ struct resource * __request_region(struct resource *parent,
 	res->name = name;
 	res->start = start;
 	res->end = start + n - 1;
-	res->flags = resource_type(parent) | resource_ext_type(parent);
-	res->flags |= IORESOURCE_BUSY | flags;
-	res->desc = IORES_DESC_NONE;
 
 	write_lock(&resource_lock);
 
 	for (;;) {
 		struct resource *conflict;
 
+		res->flags = resource_type(parent) | resource_ext_type(parent);
+		res->flags |= IORESOURCE_BUSY | flags;
+		res->desc = parent->desc;
+
 		conflict = __request_resource(parent, res);
 		if (!conflict)
 			break;
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index b3281dcd4a5d..3187322eeed7 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -151,6 +151,11 @@ struct nfit_test {
 	int (*alloc)(struct nfit_test *t);
 	void (*setup)(struct nfit_test *t);
 	int setup_hotplug;
+	struct ars_state {
+		struct nd_cmd_ars_status *ars_status;
+		unsigned long deadline;
+		spinlock_t lock;
+	} ars_state;
 };
 
 static struct nfit_test *to_nfit_test(struct device *dev)
@@ -218,6 +223,7 @@ static int nfit_test_cmd_set_config_data(struct nd_cmd_set_config_hdr *nd_cmd,
 }
 
 #define NFIT_TEST_ARS_RECORDS 4
+#define NFIT_TEST_CLEAR_ERR_UNIT 256
 
 static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap *nd_cmd,
 		unsigned int buf_len)
@@ -228,44 +234,113 @@ static int nfit_test_cmd_ars_cap(struct nd_cmd_ars_cap *nd_cmd,
 	nd_cmd->max_ars_out = sizeof(struct nd_cmd_ars_status)
 		+ NFIT_TEST_ARS_RECORDS * sizeof(struct nd_ars_record);
 	nd_cmd->status = (ND_ARS_PERSISTENT | ND_ARS_VOLATILE) << 16;
+	nd_cmd->clear_err_unit = NFIT_TEST_CLEAR_ERR_UNIT;
 
 	return 0;
 }
 
-static int nfit_test_cmd_ars_start(struct nd_cmd_ars_start *nd_cmd,
-		unsigned int buf_len)
+/*
+ * Initialize the ars_state to return an ars_result 1 second in the future with
+ * a 4K error range in the middle of the requested address range.
+ */
+static void post_ars_status(struct ars_state *ars_state, u64 addr, u64 len)
 {
-	if (buf_len < sizeof(*nd_cmd))
+	struct nd_cmd_ars_status *ars_status;
+	struct nd_ars_record *ars_record;
+
+	ars_state->deadline = jiffies + 1*HZ;
+	ars_status = ars_state->ars_status;
+	ars_status->status = 0;
+	ars_status->out_length = sizeof(struct nd_cmd_ars_status)
+		+ sizeof(struct nd_ars_record);
+	ars_status->address = addr;
+	ars_status->length = len;
+	ars_status->type = ND_ARS_PERSISTENT;
+	ars_status->num_records = 1;
+	ars_record = &ars_status->records[0];
+	ars_record->handle = 0;
+	ars_record->err_address = addr + len / 2;
+	ars_record->length = SZ_4K;
+}
+
+static int nfit_test_cmd_ars_start(struct ars_state *ars_state,
+		struct nd_cmd_ars_start *ars_start, unsigned int buf_len,
+		int *cmd_rc)
+{
+	if (buf_len < sizeof(*ars_start))
 		return -EINVAL;
 
-	nd_cmd->status = 0;
+	spin_lock(&ars_state->lock);
+	if (time_before(jiffies, ars_state->deadline)) {
+		ars_start->status = NFIT_ARS_START_BUSY;
+		*cmd_rc = -EBUSY;
+	} else {
+		ars_start->status = 0;
+		ars_start->scrub_time = 1;
+		post_ars_status(ars_state, ars_start->address,
+				ars_start->length);
+		*cmd_rc = 0;
+	}
+	spin_unlock(&ars_state->lock);
 
 	return 0;
 }
 
-static int nfit_test_cmd_ars_status(struct nd_cmd_ars_status *nd_cmd,
-		unsigned int buf_len)
+static int nfit_test_cmd_ars_status(struct ars_state *ars_state,
+		struct nd_cmd_ars_status *ars_status, unsigned int buf_len,
+		int *cmd_rc)
 {
-	if (buf_len < sizeof(*nd_cmd))
+	if (buf_len < ars_state->ars_status->out_length)
 		return -EINVAL;
 
-	nd_cmd->out_length = sizeof(struct nd_cmd_ars_status);
-	/* TODO: emit error records */
-	nd_cmd->num_records = 0;
-	nd_cmd->address = 0;
-	nd_cmd->length = -1ULL;
-	nd_cmd->status = 0;
+	spin_lock(&ars_state->lock);
+	if (time_before(jiffies, ars_state->deadline)) {
+		memset(ars_status, 0, buf_len);
+		ars_status->status = NFIT_ARS_STATUS_BUSY;
+		ars_status->out_length = sizeof(*ars_status);
+		*cmd_rc = -EBUSY;
+	} else {
+		memcpy(ars_status, ars_state->ars_status,
+				ars_state->ars_status->out_length);
+		*cmd_rc = 0;
+	}
+	spin_unlock(&ars_state->lock);
+	return 0;
+}
 
+static int nfit_test_cmd_clear_error(struct nd_cmd_clear_error *clear_err,
+		unsigned int buf_len, int *cmd_rc)
+{
+	const u64 mask = NFIT_TEST_CLEAR_ERR_UNIT - 1;
+	if (buf_len < sizeof(*clear_err))
+		return -EINVAL;
+
+	if ((clear_err->address & mask) || (clear_err->length & mask))
+		return -EINVAL;
+
+	/*
+	 * Report 'all clear' success for all commands even though a new
+	 * scrub will find errors again.  This is enough to have the
+	 * error removed from the 'badblocks' tracking in the pmem
+	 * driver.
+	 */
+	clear_err->status = 0;
+	clear_err->cleared = clear_err->length;
+	*cmd_rc = 0;
 	return 0;
 }
 
 static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd, void *buf,
-		unsigned int buf_len)
+		unsigned int buf_len, int *cmd_rc)
 {
 	struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
 	struct nfit_test *t = container_of(acpi_desc, typeof(*t), acpi_desc);
-	int i, rc = 0;
+	int i, rc = 0, __cmd_rc;
+
+	if (!cmd_rc)
+		cmd_rc = &__cmd_rc;
+	*cmd_rc = 0;
 
 	if (nvdimm) {
 		struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
@@ -297,6 +372,8 @@ static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
 			return -ENOTTY;
 		}
 	} else {
+		struct ars_state *ars_state = &t->ars_state;
+
 		if (!nd_desc || !test_bit(cmd, &nd_desc->dsm_mask))
 			return -ENOTTY;
 
@@ -305,10 +382,15 @@ static int nfit_test_ctl(struct nvdimm_bus_descriptor *nd_desc,
 			rc = nfit_test_cmd_ars_cap(buf, buf_len);
 			break;
 		case ND_CMD_ARS_START:
-			rc = nfit_test_cmd_ars_start(buf, buf_len);
+			rc = nfit_test_cmd_ars_start(ars_state, buf, buf_len,
+					cmd_rc);
 			break;
 		case ND_CMD_ARS_STATUS:
-			rc = nfit_test_cmd_ars_status(buf, buf_len);
+			rc = nfit_test_cmd_ars_status(ars_state, buf, buf_len,
+					cmd_rc);
+			break;
+		case ND_CMD_CLEAR_ERROR:
+			rc = nfit_test_cmd_clear_error(buf, buf_len, cmd_rc);
 			break;
 		default:
 			return -ENOTTY;
@@ -424,11 +506,25 @@ static struct nfit_test_resource *nfit_test_lookup(resource_size_t addr)
 	return NULL;
 }
 
+static int ars_state_init(struct device *dev, struct ars_state *ars_state)
+{
+	ars_state->ars_status = devm_kzalloc(dev,
+			sizeof(struct nd_cmd_ars_status)
+			+ sizeof(struct nd_ars_record) * NFIT_TEST_ARS_RECORDS,
+			GFP_KERNEL);
+	if (!ars_state->ars_status)
+		return -ENOMEM;
+	spin_lock_init(&ars_state->lock);
+	return 0;
+}
+
 static int nfit_test0_alloc(struct nfit_test *t)
 {
 	size_t nfit_size = sizeof(struct acpi_nfit_system_address) * NUM_SPA
 			+ sizeof(struct acpi_nfit_memory_map) * NUM_MEM
 			+ sizeof(struct acpi_nfit_control_region) * NUM_DCR
+			+ offsetof(struct acpi_nfit_control_region,
+					window_size) * NUM_DCR
 			+ sizeof(struct acpi_nfit_data_region) * NUM_BDW
 			+ sizeof(struct acpi_nfit_flush_address) * NUM_DCR;
 	int i;
@@ -471,14 +567,14 @@ static int nfit_test0_alloc(struct nfit_test *t)
 			return -ENOMEM;
 	}
 
-	return 0;
+	return ars_state_init(&t->pdev.dev, &t->ars_state);
 }
 
 static int nfit_test1_alloc(struct nfit_test *t)
 {
 	size_t nfit_size = sizeof(struct acpi_nfit_system_address)
 		+ sizeof(struct acpi_nfit_memory_map)
-		+ sizeof(struct acpi_nfit_control_region);
+		+ offsetof(struct acpi_nfit_control_region, window_size);
 
 	t->nfit_buf = test_alloc(t, nfit_size, &t->nfit_dma);
 	if (!t->nfit_buf)
@@ -489,12 +585,11 @@ static int nfit_test1_alloc(struct nfit_test *t)
 	if (!t->spa_set[0])
 		return -ENOMEM;
 
-	return 0;
+	return ars_state_init(&t->pdev.dev, &t->ars_state);
 }
 
 static void nfit_test0_setup(struct nfit_test *t)
 {
-	struct nvdimm_bus_descriptor *nd_desc;
 	struct acpi_nfit_desc *acpi_desc;
 	struct acpi_nfit_memory_map *memdev;
 	void *nfit_buf = t->nfit_buf;
@@ -611,7 +706,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 0;
 	memdev->region_id = 0;
 	memdev->range_index = 0+1;
-	memdev->region_index = 0+1;
+	memdev->region_index = 4+1;
 	memdev->region_size = SPA0_SIZE/2;
 	memdev->region_offset = t->spa_set_dma[0];
 	memdev->address = 0;
@@ -626,7 +721,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 1;
 	memdev->region_id = 0;
 	memdev->range_index = 0+1;
-	memdev->region_index = 1+1;
+	memdev->region_index = 5+1;
 	memdev->region_size = SPA0_SIZE/2;
 	memdev->region_offset = t->spa_set_dma[0] + SPA0_SIZE/2;
 	memdev->address = 0;
@@ -641,7 +736,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 0;
 	memdev->region_id = 1;
 	memdev->range_index = 1+1;
-	memdev->region_index = 0+1;
+	memdev->region_index = 4+1;
 	memdev->region_size = SPA1_SIZE/4;
 	memdev->region_offset = t->spa_set_dma[1];
 	memdev->address = SPA0_SIZE/2;
@@ -656,7 +751,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 1;
 	memdev->region_id = 1;
 	memdev->range_index = 1+1;
-	memdev->region_index = 1+1;
+	memdev->region_index = 5+1;
 	memdev->region_size = SPA1_SIZE/4;
 	memdev->region_offset = t->spa_set_dma[1] + SPA1_SIZE/4;
 	memdev->address = SPA0_SIZE/2;
@@ -671,7 +766,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 2;
 	memdev->region_id = 0;
 	memdev->range_index = 1+1;
-	memdev->region_index = 2+1;
+	memdev->region_index = 6+1;
 	memdev->region_size = SPA1_SIZE/4;
 	memdev->region_offset = t->spa_set_dma[1] + 2*SPA1_SIZE/4;
 	memdev->address = SPA0_SIZE/2;
@@ -686,7 +781,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->physical_id = 3;
 	memdev->region_id = 0;
 	memdev->range_index = 1+1;
-	memdev->region_index = 3+1;
+	memdev->region_index = 7+1;
 	memdev->region_size = SPA1_SIZE/4;
 	memdev->region_offset = t->spa_set_dma[1] + 3*SPA1_SIZE/4;
 	memdev->address = SPA0_SIZE/2;
@@ -814,7 +909,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	memdev->interleave_ways = 1;
 
 	offset = offset + sizeof(struct acpi_nfit_memory_map) * 14;
-	/* dcr-descriptor0 */
+	/* dcr-descriptor0: blk */
 	dcr = nfit_buf + offset;
 	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
 	dcr->header.length = sizeof(struct acpi_nfit_control_region);
@@ -823,6 +918,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->device_id = 0;
 	dcr->revision_id = 1;
 	dcr->serial_number = ~handle[0];
+	dcr->code = NFIT_FIC_BLK;
 	dcr->windows = 1;
 	dcr->window_size = DCR_SIZE;
 	dcr->command_offset = 0;
@@ -830,7 +926,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->status_offset = 8;
 	dcr->status_size = 4;
 
-	/* dcr-descriptor1 */
+	/* dcr-descriptor1: blk */
 	dcr = nfit_buf + offset + sizeof(struct acpi_nfit_control_region);
 	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
 	dcr->header.length = sizeof(struct acpi_nfit_control_region);
@@ -839,6 +935,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->device_id = 0;
 	dcr->revision_id = 1;
 	dcr->serial_number = ~handle[1];
+	dcr->code = NFIT_FIC_BLK;
 	dcr->windows = 1;
 	dcr->window_size = DCR_SIZE;
 	dcr->command_offset = 0;
@@ -846,7 +943,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->status_offset = 8;
 	dcr->status_size = 4;
 
-	/* dcr-descriptor2 */
+	/* dcr-descriptor2: blk */
 	dcr = nfit_buf + offset + sizeof(struct acpi_nfit_control_region) * 2;
 	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
 	dcr->header.length = sizeof(struct acpi_nfit_control_region);
@@ -855,6 +952,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->device_id = 0;
 	dcr->revision_id = 1;
 	dcr->serial_number = ~handle[2];
+	dcr->code = NFIT_FIC_BLK;
 	dcr->windows = 1;
 	dcr->window_size = DCR_SIZE;
 	dcr->command_offset = 0;
@@ -862,7 +960,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->status_offset = 8;
 	dcr->status_size = 4;
 
-	/* dcr-descriptor3 */
+	/* dcr-descriptor3: blk */
 	dcr = nfit_buf + offset + sizeof(struct acpi_nfit_control_region) * 3;
 	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
 	dcr->header.length = sizeof(struct acpi_nfit_control_region);
@@ -871,6 +969,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->device_id = 0;
 	dcr->revision_id = 1;
 	dcr->serial_number = ~handle[3];
+	dcr->code = NFIT_FIC_BLK;
 	dcr->windows = 1;
 	dcr->window_size = DCR_SIZE;
 	dcr->command_offset = 0;
@@ -879,6 +978,63 @@ static void nfit_test0_setup(struct nfit_test *t)
 	dcr->status_size = 4;
 
 	offset = offset + sizeof(struct acpi_nfit_control_region) * 4;
+	/* dcr-descriptor0: pmem */
+	dcr = nfit_buf + offset;
+	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+	dcr->header.length = offsetof(struct acpi_nfit_control_region,
+			window_size);
+	dcr->region_index = 4+1;
+	dcr->vendor_id = 0xabcd;
+	dcr->device_id = 0;
+	dcr->revision_id = 1;
+	dcr->serial_number = ~handle[0];
+	dcr->code = NFIT_FIC_BYTEN;
+	dcr->windows = 0;
+
+	/* dcr-descriptor1: pmem */
+	dcr = nfit_buf + offset + offsetof(struct acpi_nfit_control_region,
+			window_size);
+	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+	dcr->header.length = offsetof(struct acpi_nfit_control_region,
+			window_size);
+	dcr->region_index = 5+1;
+	dcr->vendor_id = 0xabcd;
+	dcr->device_id = 0;
+	dcr->revision_id = 1;
+	dcr->serial_number = ~handle[1];
+	dcr->code = NFIT_FIC_BYTEN;
+	dcr->windows = 0;
+
+	/* dcr-descriptor2: pmem */
+	dcr = nfit_buf + offset + offsetof(struct acpi_nfit_control_region,
+			window_size) * 2;
+	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+	dcr->header.length = offsetof(struct acpi_nfit_control_region,
+			window_size);
+	dcr->region_index = 6+1;
+	dcr->vendor_id = 0xabcd;
+	dcr->device_id = 0;
+	dcr->revision_id = 1;
+	dcr->serial_number = ~handle[2];
+	dcr->code = NFIT_FIC_BYTEN;
+	dcr->windows = 0;
+
+	/* dcr-descriptor3: pmem */
+	dcr = nfit_buf + offset + offsetof(struct acpi_nfit_control_region,
+			window_size) * 3;
+	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+	dcr->header.length = offsetof(struct acpi_nfit_control_region,
+			window_size);
+	dcr->region_index = 7+1;
+	dcr->vendor_id = 0xabcd;
+	dcr->device_id = 0;
+	dcr->revision_id = 1;
+	dcr->serial_number = ~handle[3];
+	dcr->code = NFIT_FIC_BYTEN;
+	dcr->windows = 0;
+
+	offset = offset + offsetof(struct acpi_nfit_control_region,
+			window_size) * 4;
 	/* bdw0 (spa/dcr0, dimm0) */
 	bdw = nfit_buf + offset;
 	bdw->header.type = ACPI_NFIT_TYPE_DATA_REGION;
@@ -958,15 +1114,16 @@ static void nfit_test0_setup(struct nfit_test *t)
 
 	if (t->setup_hotplug) {
 		offset = offset + sizeof(struct acpi_nfit_flush_address) * 4;
-		/* dcr-descriptor4 */
+		/* dcr-descriptor4: blk */
 		dcr = nfit_buf + offset;
 		dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
 		dcr->header.length = sizeof(struct acpi_nfit_control_region);
-		dcr->region_index = 4+1;
+		dcr->region_index = 8+1;
 		dcr->vendor_id = 0xabcd;
 		dcr->device_id = 0;
 		dcr->revision_id = 1;
 		dcr->serial_number = ~handle[4];
+		dcr->code = NFIT_FIC_BLK;
 		dcr->windows = 1;
 		dcr->window_size = DCR_SIZE;
 		dcr->command_offset = 0;
@@ -975,11 +1132,26 @@ static void nfit_test0_setup(struct nfit_test *t)
 		dcr->status_size = 4;
 
 		offset = offset + sizeof(struct acpi_nfit_control_region);
+		/* dcr-descriptor4: pmem */
+		dcr = nfit_buf + offset;
+		dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
+		dcr->header.length = offsetof(struct acpi_nfit_control_region,
+				window_size);
+		dcr->region_index = 9+1;
+		dcr->vendor_id = 0xabcd;
+		dcr->device_id = 0;
+		dcr->revision_id = 1;
+		dcr->serial_number = ~handle[4];
+		dcr->code = NFIT_FIC_BYTEN;
+		dcr->windows = 0;
+
+		offset = offset + offsetof(struct acpi_nfit_control_region,
+				window_size);
 		/* bdw4 (spa/dcr4, dimm4) */
 		bdw = nfit_buf + offset;
 		bdw->header.type = ACPI_NFIT_TYPE_DATA_REGION;
 		bdw->header.length = sizeof(struct acpi_nfit_data_region);
-		bdw->region_index = 4+1;
+		bdw->region_index = 8+1;
 		bdw->windows = 1;
 		bdw->offset = 0;
 		bdw->size = BDW_SIZE;
@@ -1027,7 +1199,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 		memdev->physical_id = 4;
 		memdev->region_id = 0;
 		memdev->range_index = 10+1;
-		memdev->region_index = 4+1;
+		memdev->region_index = 8+1;
 		memdev->region_size = 0;
 		memdev->region_offset = 0;
 		memdev->address = 0;
@@ -1043,14 +1215,14 @@ static void nfit_test0_setup(struct nfit_test *t)
 		memdev->physical_id = 4;
 		memdev->region_id = 0;
 		memdev->range_index = 11+1;
-		memdev->region_index = 4+1;
+		memdev->region_index = 9+1;
 		memdev->region_size = SPA0_SIZE;
 		memdev->region_offset = t->spa_set_dma[2];
 		memdev->address = 0;
 		memdev->interleave_index = 0;
 		memdev->interleave_ways = 1;
 
-		/* mem-region16 (spa/dcr4, dimm4) */
+		/* mem-region16 (spa/bdw4, dimm4) */
 		memdev = nfit_buf + offset +
 				sizeof(struct acpi_nfit_memory_map) * 2;
 		memdev->header.type = ACPI_NFIT_TYPE_MEMORY_MAP;
@@ -1059,7 +1231,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 		memdev->physical_id = 4;
 		memdev->region_id = 0;
 		memdev->range_index = 12+1;
-		memdev->region_index = 4+1;
+		memdev->region_index = 8+1;
 		memdev->region_size = 0;
 		memdev->region_offset = 0;
 		memdev->address = 0;
@@ -1076,6 +1248,8 @@ static void nfit_test0_setup(struct nfit_test *t)
 		flush->hint_address[0] = t->flush_dma[4];
 	}
 
+	post_ars_status(&t->ars_state, t->spa_set_dma[0], SPA0_SIZE);
+
 	acpi_desc = &t->acpi_desc;
 	set_bit(ND_CMD_GET_CONFIG_SIZE, &acpi_desc->dimm_dsm_force_en);
 	set_bit(ND_CMD_GET_CONFIG_DATA, &acpi_desc->dimm_dsm_force_en);
@@ -1083,8 +1257,7 @@ static void nfit_test0_setup(struct nfit_test *t)
 	set_bit(ND_CMD_ARS_CAP, &acpi_desc->bus_dsm_force_en);
 	set_bit(ND_CMD_ARS_START, &acpi_desc->bus_dsm_force_en);
 	set_bit(ND_CMD_ARS_STATUS, &acpi_desc->bus_dsm_force_en);
-	nd_desc = &acpi_desc->nd_desc;
-	nd_desc->ndctl = nfit_test_ctl;
+	set_bit(ND_CMD_CLEAR_ERROR, &acpi_desc->bus_dsm_force_en);
 }
 
 static void nfit_test1_setup(struct nfit_test *t)
@@ -1094,7 +1267,6 @@ static void nfit_test1_setup(struct nfit_test *t)
 	struct acpi_nfit_memory_map *memdev;
 	struct acpi_nfit_control_region *dcr;
 	struct acpi_nfit_system_address *spa;
-	struct nvdimm_bus_descriptor *nd_desc;
 	struct acpi_nfit_desc *acpi_desc;
 
 	offset = 0;
@@ -1130,26 +1302,23 @@ static void nfit_test1_setup(struct nfit_test *t)
 	/* dcr-descriptor0 */
 	dcr = nfit_buf + offset;
 	dcr->header.type = ACPI_NFIT_TYPE_CONTROL_REGION;
-	dcr->header.length = sizeof(struct acpi_nfit_control_region);
+	dcr->header.length = offsetof(struct acpi_nfit_control_region,
+			window_size);
 	dcr->region_index = 0+1;
 	dcr->vendor_id = 0xabcd;
 	dcr->device_id = 0;
 	dcr->revision_id = 1;
 	dcr->serial_number = ~0;
-	dcr->code = 0x201;
+	dcr->code = NFIT_FIC_BYTE;
 	dcr->windows = 0;
-	dcr->window_size = 0;
-	dcr->command_offset = 0;
-	dcr->command_size = 0;
-	dcr->status_offset = 0;
-	dcr->status_size = 0;
+
+	post_ars_status(&t->ars_state, t->spa_set_dma[0], SPA2_SIZE);
 
 	acpi_desc = &t->acpi_desc;
 	set_bit(ND_CMD_ARS_CAP, &acpi_desc->bus_dsm_force_en);
 	set_bit(ND_CMD_ARS_START, &acpi_desc->bus_dsm_force_en);
 	set_bit(ND_CMD_ARS_STATUS, &acpi_desc->bus_dsm_force_en);
-	nd_desc = &acpi_desc->nd_desc;
-	nd_desc->ndctl = nfit_test_ctl;
+	set_bit(ND_CMD_CLEAR_ERROR, &acpi_desc->bus_dsm_force_en);
 }
 
 static int nfit_test_blk_do_io(struct nd_blk_region *ndbr, resource_size_t dpa,
@@ -1232,26 +1401,16 @@ static int nfit_test_probe(struct platform_device *pdev)
 
 	nfit_test->setup(nfit_test);
 	acpi_desc = &nfit_test->acpi_desc;
-	acpi_desc->dev = &pdev->dev;
+	acpi_nfit_desc_init(acpi_desc, &pdev->dev);
 	acpi_desc->nfit = nfit_test->nfit_buf;
 	acpi_desc->blk_do_io = nfit_test_blk_do_io;
 	nd_desc = &acpi_desc->nd_desc;
-	nd_desc->attr_groups = acpi_nfit_attribute_groups;
+	nd_desc->provider_name = NULL;
+	nd_desc->ndctl = nfit_test_ctl;
 	acpi_desc->nvdimm_bus = nvdimm_bus_register(&pdev->dev, nd_desc);
 	if (!acpi_desc->nvdimm_bus)
 		return -ENXIO;
 
-	INIT_LIST_HEAD(&acpi_desc->spa_maps);
-	INIT_LIST_HEAD(&acpi_desc->spas);
-	INIT_LIST_HEAD(&acpi_desc->dcrs);
-	INIT_LIST_HEAD(&acpi_desc->bdws);
-	INIT_LIST_HEAD(&acpi_desc->idts);
-	INIT_LIST_HEAD(&acpi_desc->flushes);
-	INIT_LIST_HEAD(&acpi_desc->memdevs);
-	INIT_LIST_HEAD(&acpi_desc->dimms);
-	mutex_init(&acpi_desc->spa_map_mutex);
-	mutex_init(&acpi_desc->init_mutex);
-
 	rc = acpi_nfit_init(acpi_desc, nfit_test->nfit_size);
 	if (rc) {
 		nvdimm_bus_unregister(acpi_desc->nvdimm_bus);