Merge tag 'libnvdimm-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams: "This cycle was was not something I ever want to repeat as there were several late changes that have only now just settled. Half of the branch up to commit d2c997c0f145 ("fs, dax: use page->mapping to warn...") have been in -next for several releases. The of_pmem driver and the address range scrub rework were late arrivals, and the dax work was scaled back at the last moment. The of_pmem driver missed a previous merge window due to an oversight. A sense of obligation to rectify that miss is why it is included for 4.17. It has acks from PowerPC folks. Stephen reported a build failure that only occurs when merging it with your latest tree, for now I have fixed that up by disabling modular builds of of_pmem. A test merge with your tree has received a build success report from the 0day robot over 156 configs. An initial version of the ARS rework was submitted before the merge window. It is self contained to libnvdimm, a net code reduction, and passing all unit tests. The filesystem-dax changes are based on the wait_var_event() functionality from tip/sched/core. However, late review feedback showed that those changes regressed truncate performance to a large degree. The branch was rewound to drop the truncate behavior change and now only includes preparation patches and cleanups (with full acks and reviews). The finalization of this dax-dma-vs-trnucate work will need to wait for 4.18. Summary: - A rework of the filesytem-dax implementation provides for detection of unmap operations (truncate / hole punch) colliding with in-progress device-DMA. A fix for these collisions remains a work-in-progress pending resolution of truncate latency and starvation regressions. - The of_pmem driver expands the users of libnvdimm outside of x86 and ACPI to describe an implementation of persistent memory on PowerPC with Open Firmware / Device tree. - Address Range Scrub (ARS) handling is completely rewritten to account for the fact that ARS may run for 100s of seconds and there is no platform defined way to cancel it. ARS will now no longer block namespace initialization. - The NVDIMM Namespace Label implementation is updated to handle label areas as small as 1K, down from 128K. - Miscellaneous cleanups and updates to unit test infrastructure" * tag 'libnvdimm-for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (39 commits) libnvdimm, of_pmem: workaround OF_NUMA=n build error nfit, address-range-scrub: add module option to skip initial ars nfit, address-range-scrub: rework and simplify ARS state machine nfit, address-range-scrub: determine one platform max_ars value powerpc/powernv: Create platform devs for nvdimm buses doc/devicetree: Persistent memory region bindings libnvdimm: Add device-tree based driver libnvdimm: Add of_node to region and bus descriptors libnvdimm, region: quiet region probe libnvdimm, namespace: use a safe lookup for dimm device name libnvdimm, dimm: fix dpa reservation vs uninitialized label area libnvdimm, testing: update the default smart ctrl_temperature libnvdimm, testing: Add emulation for smart injection commands nfit, address-range-scrub: introduce nfit_spa->ars_state libnvdimm: add an api to cast a 'struct nd_region' to its 'struct device' nfit, address-range-scrub: fix scrub in-progress reporting dax, dm: allow device-mapper to operate without dax support dax: introduce CONFIG_DAX_DRIVER fs, dax: use page->mapping to warn if truncate collides with a busy page ext2, dax: introduce ext2_dax_aops ...
author: Linus Torvalds <torvalds@linux-foundation.org> 2018-04-10 10:25:57 -0700
committer: Linus Torvalds <torvalds@linux-foundation.org> 2018-04-10 10:25:57 -0700
commit: 9f3a0941fb5efaa4d27911e251dc595034d58baa (patch)
tree: 7212d9872b41b73a0b3c4f8c991039b639add212 /drivers
parent: fbe173e3ffbd897b5a859020d714c0eaf4af2a1a (diff)
parent: e13e75b86ef2f88e3a47d672dd4c52a293efb95b (diff)
31 files changed, 700 insertions, 581 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 22a112b4f4d8..e2235ed3e4be 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -36,16 +36,6 @@ 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 bool disable_vendor_specific;
 module_param(disable_vendor_specific, bool, S_IRUGO);
 MODULE_PARM_DESC(disable_vendor_specific,
@@ -60,6 +50,10 @@ module_param(default_dsm_family, int, S_IRUGO);
 MODULE_PARM_DESC(default_dsm_family,
 		"Try this DSM type first when identifying NVDIMM family");
 
+static bool no_init_ars;
+module_param(no_init_ars, bool, 0644);
+MODULE_PARM_DESC(no_init_ars, "Skip ARS run at nfit init time");
+
 LIST_HEAD(acpi_descs);
 DEFINE_MUTEX(acpi_desc_lock);
 
@@ -197,7 +191,7 @@ static int xlat_nvdimm_status(struct nvdimm *nvdimm, void *buf, unsigned int cmd
 		 * In the _LSI, _LSR, _LSW case the locked status is
 		 * communicated via the read/write commands
 		 */
-		if (nfit_mem->has_lsi)
+		if (nfit_mem->has_lsr)
 			break;
 
 		if (status >> 16 & ND_CONFIG_LOCKED)
@@ -477,14 +471,14 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 		in_buf.buffer.length = call_pkg->nd_size_in;
 	}
 
-	dev_dbg(dev, "%s:%s cmd: %d: func: %d input length: %d\n",
-			__func__, dimm_name, cmd, func, in_buf.buffer.length);
+	dev_dbg(dev, "%s cmd: %d: func: %d input length: %d\n",
+		dimm_name, cmd, func, in_buf.buffer.length);
 	print_hex_dump_debug("nvdimm in  ", DUMP_PREFIX_OFFSET, 4, 4,
 			in_buf.buffer.pointer,
 			min_t(u32, 256, in_buf.buffer.length), true);
 
 	/* call the BIOS, prefer the named methods over _DSM if available */
-	if (nvdimm && cmd == ND_CMD_GET_CONFIG_SIZE && nfit_mem->has_lsi)
+	if (nvdimm && cmd == ND_CMD_GET_CONFIG_SIZE && nfit_mem->has_lsr)
 		out_obj = acpi_label_info(handle);
 	else if (nvdimm && cmd == ND_CMD_GET_CONFIG_DATA && nfit_mem->has_lsr) {
 		struct nd_cmd_get_config_data_hdr *p = buf;
@@ -507,8 +501,7 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	}
 
 	if (!out_obj) {
-		dev_dbg(dev, "%s:%s _DSM failed cmd: %s\n", __func__, dimm_name,
-				cmd_name);
+		dev_dbg(dev, "%s _DSM failed cmd: %s\n", dimm_name, cmd_name);
 		return -EINVAL;
 	}
 
@@ -529,13 +522,13 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 	}
 
 	if (out_obj->package.type != ACPI_TYPE_BUFFER) {
-		dev_dbg(dev, "%s:%s unexpected output object type cmd: %s type: %d\n",
-				__func__, dimm_name, cmd_name, out_obj->type);
+		dev_dbg(dev, "%s unexpected output object type cmd: %s type: %d\n",
+				dimm_name, cmd_name, out_obj->type);
 		rc = -EINVAL;
 		goto out;
 	}
 
-	dev_dbg(dev, "%s:%s cmd: %s output length: %d\n", __func__, dimm_name,
+	dev_dbg(dev, "%s cmd: %s output length: %d\n", dimm_name,
 			cmd_name, out_obj->buffer.length);
 	print_hex_dump_debug(cmd_name, DUMP_PREFIX_OFFSET, 4, 4,
 			out_obj->buffer.pointer,
@@ -547,14 +540,14 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
 				out_obj->buffer.length - offset);
 
 		if (offset + out_size > out_obj->buffer.length) {
-			dev_dbg(dev, "%s:%s output object underflow cmd: %s field: %d\n",
-					__func__, dimm_name, cmd_name, i);
+			dev_dbg(dev, "%s output object underflow cmd: %s field: %d\n",
+					dimm_name, cmd_name, i);
 			break;
 		}
 
 		if (in_buf.buffer.length + offset + out_size > buf_len) {
-			dev_dbg(dev, "%s:%s output overrun cmd: %s field: %d\n",
-					__func__, dimm_name, cmd_name, i);
+			dev_dbg(dev, "%s output overrun cmd: %s field: %d\n",
+					dimm_name, cmd_name, i);
 			rc = -ENXIO;
 			goto out;
 		}
@@ -656,7 +649,7 @@ static bool add_spa(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_spa->list);
 	memcpy(nfit_spa->spa, spa, sizeof(*spa));
 	list_add_tail(&nfit_spa->list, &acpi_desc->spas);
-	dev_dbg(dev, "%s: spa index: %d type: %s\n", __func__,
+	dev_dbg(dev, "spa index: %d type: %s\n",
 			spa->range_index,
 			spa_type_name(nfit_spa_type(spa)));
 	return true;
@@ -685,8 +678,8 @@ static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_memdev->list);
 	memcpy(nfit_memdev->memdev, memdev, sizeof(*memdev));
 	list_add_tail(&nfit_memdev->list, &acpi_desc->memdevs);
-	dev_dbg(dev, "%s: memdev handle: %#x spa: %d dcr: %d flags: %#x\n",
-			__func__, memdev->device_handle, memdev->range_index,
+	dev_dbg(dev, "memdev handle: %#x spa: %d dcr: %d flags: %#x\n",
+			memdev->device_handle, memdev->range_index,
 			memdev->region_index, memdev->flags);
 	return true;
 }
@@ -754,7 +747,7 @@ static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_dcr->list);
 	memcpy(nfit_dcr->dcr, dcr, sizeof_dcr(dcr));
 	list_add_tail(&nfit_dcr->list, &acpi_desc->dcrs);
-	dev_dbg(dev, "%s: dcr index: %d windows: %d\n", __func__,
+	dev_dbg(dev, "dcr index: %d windows: %d\n",
 			dcr->region_index, dcr->windows);
 	return true;
 }
@@ -781,7 +774,7 @@ static bool add_bdw(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_bdw->list);
 	memcpy(nfit_bdw->bdw, bdw, sizeof(*bdw));
 	list_add_tail(&nfit_bdw->list, &acpi_desc->bdws);
-	dev_dbg(dev, "%s: bdw dcr: %d windows: %d\n", __func__,
+	dev_dbg(dev, "bdw dcr: %d windows: %d\n",
 			bdw->region_index, bdw->windows);
 	return true;
 }
@@ -820,7 +813,7 @@ static bool add_idt(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_idt->list);
 	memcpy(nfit_idt->idt, idt, sizeof_idt(idt));
 	list_add_tail(&nfit_idt->list, &acpi_desc->idts);
-	dev_dbg(dev, "%s: idt index: %d num_lines: %d\n", __func__,
+	dev_dbg(dev, "idt index: %d num_lines: %d\n",
 			idt->interleave_index, idt->line_count);
 	return true;
 }
@@ -860,7 +853,7 @@ static bool add_flush(struct acpi_nfit_desc *acpi_desc,
 	INIT_LIST_HEAD(&nfit_flush->list);
 	memcpy(nfit_flush->flush, flush, sizeof_flush(flush));
 	list_add_tail(&nfit_flush->list, &acpi_desc->flushes);
-	dev_dbg(dev, "%s: nfit_flush handle: %d hint_count: %d\n", __func__,
+	dev_dbg(dev, "nfit_flush handle: %d hint_count: %d\n",
 			flush->device_handle, flush->hint_count);
 	return true;
 }
@@ -873,7 +866,7 @@ static bool add_platform_cap(struct acpi_nfit_desc *acpi_desc,
 
 	mask = (1 << (pcap->highest_capability + 1)) - 1;
 	acpi_desc->platform_cap = pcap->capabilities & mask;
-	dev_dbg(dev, "%s: cap: %#x\n", __func__, acpi_desc->platform_cap);
+	dev_dbg(dev, "cap: %#x\n", acpi_desc->platform_cap);
 	return true;
 }
 
@@ -920,7 +913,7 @@ static void *add_table(struct acpi_nfit_desc *acpi_desc,
 			return err;
 		break;
 	case ACPI_NFIT_TYPE_SMBIOS:
-		dev_dbg(dev, "%s: smbios\n", __func__);
+		dev_dbg(dev, "smbios\n");
 		break;
 	case ACPI_NFIT_TYPE_CAPABILITIES:
 		if (!add_platform_cap(acpi_desc, table))
@@ -1277,8 +1270,11 @@ static ssize_t scrub_show(struct device *dev,
 	if (nd_desc) {
 		struct acpi_nfit_desc *acpi_desc = to_acpi_desc(nd_desc);
 
+		mutex_lock(&acpi_desc->init_mutex);
 		rc = sprintf(buf, "%d%s", acpi_desc->scrub_count,
-				(work_busy(&acpi_desc->work)) ? "+\n" : "\n");
+				work_busy(&acpi_desc->dwork.work)
+				&& !acpi_desc->cancel ? "+\n" : "\n");
+		mutex_unlock(&acpi_desc->init_mutex);
 	}
 	device_unlock(dev);
 	return rc;
@@ -1648,7 +1644,7 @@ void __acpi_nvdimm_notify(struct device *dev, u32 event)
 	struct nfit_mem *nfit_mem;
 	struct acpi_nfit_desc *acpi_desc;
 
-	dev_dbg(dev->parent, "%s: %s: event: %d\n", dev_name(dev), __func__,
+	dev_dbg(dev->parent, "%s: event: %d\n", dev_name(dev),
 			event);
 
 	if (event != NFIT_NOTIFY_DIMM_HEALTH) {
@@ -1681,12 +1677,23 @@ static void acpi_nvdimm_notify(acpi_handle handle, u32 event, void *data)
 	device_unlock(dev->parent);
 }
 
+static bool acpi_nvdimm_has_method(struct acpi_device *adev, char *method)
+{
+	acpi_handle handle;
+	acpi_status status;
+
+	status = acpi_get_handle(adev->handle, method, &handle);
+
+	if (ACPI_SUCCESS(status))
+		return true;
+	return false;
+}
+
 static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 		struct nfit_mem *nfit_mem, u32 device_handle)
 {
 	struct acpi_device *adev, *adev_dimm;
 	struct device *dev = acpi_desc->dev;
-	union acpi_object *obj;
 	unsigned long dsm_mask;
 	const guid_t *guid;
 	int i;
@@ -1759,25 +1766,15 @@ static int acpi_nfit_add_dimm(struct acpi_nfit_desc *acpi_desc,
 					1ULL << i))
 			set_bit(i, &nfit_mem->dsm_mask);
 
-	obj = acpi_label_info(adev_dimm->handle);
-	if (obj) {
-		ACPI_FREE(obj);
-		nfit_mem->has_lsi = 1;
-		dev_dbg(dev, "%s: has _LSI\n", dev_name(&adev_dimm->dev));
-	}
-
-	obj = acpi_label_read(adev_dimm->handle, 0, 0);
-	if (obj) {
-		ACPI_FREE(obj);
-		nfit_mem->has_lsr = 1;
+	if (acpi_nvdimm_has_method(adev_dimm, "_LSI")
+			&& acpi_nvdimm_has_method(adev_dimm, "_LSR")) {
 		dev_dbg(dev, "%s: has _LSR\n", dev_name(&adev_dimm->dev));
+		nfit_mem->has_lsr = true;
 	}
 
-	obj = acpi_label_write(adev_dimm->handle, 0, 0, NULL);
-	if (obj) {
-		ACPI_FREE(obj);
-		nfit_mem->has_lsw = 1;
+	if (nfit_mem->has_lsr && acpi_nvdimm_has_method(adev_dimm, "_LSW")) {
 		dev_dbg(dev, "%s: has _LSW\n", dev_name(&adev_dimm->dev));
+		nfit_mem->has_lsw = true;
 	}
 
 	return 0;
@@ -1866,10 +1863,10 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 			cmd_mask |= nfit_mem->dsm_mask & NVDIMM_STANDARD_CMDMASK;
 		}
 
-		if (nfit_mem->has_lsi)
+		if (nfit_mem->has_lsr) {
 			set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
-		if (nfit_mem->has_lsr)
 			set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
+		}
 		if (nfit_mem->has_lsw)
 			set_bit(ND_CMD_SET_CONFIG_DATA, &cmd_mask);
 
@@ -2365,7 +2362,7 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	nvdimm = nd_blk_region_to_dimm(ndbr);
 	nfit_mem = nvdimm_provider_data(nvdimm);
 	if (!nfit_mem || !nfit_mem->dcr || !nfit_mem->bdw) {
-		dev_dbg(dev, "%s: missing%s%s%s\n", __func__,
+		dev_dbg(dev, "missing%s%s%s\n",
 				nfit_mem ? "" : " nfit_mem",
 				(nfit_mem && nfit_mem->dcr) ? "" : " dcr",
 				(nfit_mem && nfit_mem->bdw) ? "" : " bdw");
@@ -2384,7 +2381,7 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	mmio->addr.base = devm_nvdimm_memremap(dev, nfit_mem->spa_bdw->address,
                         nfit_mem->spa_bdw->length, nd_blk_memremap_flags(ndbr));
 	if (!mmio->addr.base) {
-		dev_dbg(dev, "%s: %s failed to map bdw\n", __func__,
+		dev_dbg(dev, "%s failed to map bdw\n",
 				nvdimm_name(nvdimm));
 		return -ENOMEM;
 	}
@@ -2395,8 +2392,8 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_bdw,
 			nfit_mem->memdev_bdw->interleave_ways);
 	if (rc) {
-		dev_dbg(dev, "%s: %s failed to init bdw interleave\n",
-				__func__, nvdimm_name(nvdimm));
+		dev_dbg(dev, "%s failed to init bdw interleave\n",
+				nvdimm_name(nvdimm));
 		return rc;
 	}
 
@@ -2407,7 +2404,7 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	mmio->addr.base = devm_nvdimm_ioremap(dev, nfit_mem->spa_dcr->address,
 			nfit_mem->spa_dcr->length);
 	if (!mmio->addr.base) {
-		dev_dbg(dev, "%s: %s failed to map dcr\n", __func__,
+		dev_dbg(dev, "%s failed to map dcr\n",
 				nvdimm_name(nvdimm));
 		return -ENOMEM;
 	}
@@ -2418,15 +2415,15 @@ static int acpi_nfit_blk_region_enable(struct nvdimm_bus *nvdimm_bus,
 	rc = nfit_blk_init_interleave(mmio, nfit_mem->idt_dcr,
 			nfit_mem->memdev_dcr->interleave_ways);
 	if (rc) {
-		dev_dbg(dev, "%s: %s failed to init dcr interleave\n",
-				__func__, nvdimm_name(nvdimm));
+		dev_dbg(dev, "%s failed to init dcr interleave\n",
+				nvdimm_name(nvdimm));
 		return rc;
 	}
 
 	rc = acpi_nfit_blk_get_flags(nd_desc, nvdimm, nfit_blk);
 	if (rc < 0) {
-		dev_dbg(dev, "%s: %s failed get DIMM flags\n",
-				__func__, nvdimm_name(nvdimm));
+		dev_dbg(dev, "%s failed get DIMM flags\n",
+				nvdimm_name(nvdimm));
 		return rc;
 	}
 
@@ -2476,7 +2473,8 @@ static int ars_start(struct acpi_nfit_desc *acpi_desc, struct nfit_spa *nfit_spa
 	memset(&ars_start, 0, sizeof(ars_start));
 	ars_start.address = spa->address;
 	ars_start.length = spa->length;
-	ars_start.flags = acpi_desc->ars_start_flags;
+	if (test_bit(ARS_SHORT, &nfit_spa->ars_state))
+		ars_start.flags = ND_ARS_RETURN_PREV_DATA;
 	if (nfit_spa_type(spa) == NFIT_SPA_PM)
 		ars_start.type = ND_ARS_PERSISTENT;
 	else if (nfit_spa_type(spa) == NFIT_SPA_VOLATILE)
@@ -2518,16 +2516,62 @@ static int ars_get_status(struct acpi_nfit_desc *acpi_desc)
 	int rc, cmd_rc;
 
 	rc = nd_desc->ndctl(nd_desc, NULL, ND_CMD_ARS_STATUS, ars_status,
-			acpi_desc->ars_status_size, &cmd_rc);
+			acpi_desc->max_ars, &cmd_rc);
 	if (rc < 0)
 		return rc;
 	return cmd_rc;
 }
 
-static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc,
-		struct nd_cmd_ars_status *ars_status)
+static void ars_complete(struct acpi_nfit_desc *acpi_desc,
+		struct nfit_spa *nfit_spa)
+{
+	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
+	struct acpi_nfit_system_address *spa = nfit_spa->spa;
+	struct nd_region *nd_region = nfit_spa->nd_region;
+	struct device *dev;
+
+	if ((ars_status->address >= spa->address && ars_status->address
+				< spa->address + spa->length)
+			|| (ars_status->address < spa->address)) {
+		/*
+		 * Assume that if a scrub starts at an offset from the
+		 * start of nfit_spa that we are in the continuation
+		 * case.
+		 *
+		 * Otherwise, if the scrub covers the spa range, mark
+		 * any pending request complete.
+		 */
+		if (ars_status->address + ars_status->length
+				>= spa->address + spa->length)
+				/* complete */;
+		else
+			return;
+	} else
+		return;
+
+	if (test_bit(ARS_DONE, &nfit_spa->ars_state))
+		return;
+
+	if (!test_and_clear_bit(ARS_REQ, &nfit_spa->ars_state))
+		return;
+
+	if (nd_region) {
+		dev = nd_region_dev(nd_region);
+		nvdimm_region_notify(nd_region, NVDIMM_REVALIDATE_POISON);
+	} else
+		dev = acpi_desc->dev;
+
+	dev_dbg(dev, "ARS: range %d %s complete\n", spa->range_index,
+			test_bit(ARS_SHORT, &nfit_spa->ars_state)
+			? "short" : "long");
+	clear_bit(ARS_SHORT, &nfit_spa->ars_state);
+	set_bit(ARS_DONE, &nfit_spa->ars_state);
+}
+
+static int ars_status_process_records(struct acpi_nfit_desc *acpi_desc)
 {
 	struct nvdimm_bus *nvdimm_bus = acpi_desc->nvdimm_bus;
+	struct nd_cmd_ars_status *ars_status = acpi_desc->ars_status;
 	int rc;
 	u32 i;
 
@@ -2606,7 +2650,7 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
 	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, rc;
+	int rc;
 
 	if (!nvdimm) {
 		dev_err(acpi_desc->dev, "spa%d dimm: %#x not found\n",
@@ -2626,15 +2670,14 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc *acpi_desc,
 		if (!nfit_mem || !nfit_mem->bdw) {
 			dev_dbg(acpi_desc->dev, "spa%d %s missing bdw\n",
 					spa->range_index, nvdimm_name(nvdimm));
-		} else {
-			mapping->size = nfit_mem->bdw->capacity;
-			mapping->start = nfit_mem->bdw->start_address;
-			ndr_desc->num_lanes = nfit_mem->bdw->windows;
-			blk_valid = 1;
+			break;
 		}
 
+		mapping->size = nfit_mem->bdw->capacity;
+		mapping->start = nfit_mem->bdw->start_address;
+		ndr_desc->num_lanes = nfit_mem->bdw->windows;
 		ndr_desc->mapping = mapping;
-		ndr_desc->num_mappings = blk_valid;
+		ndr_desc->num_mappings = 1;
 		ndbr_desc = to_blk_region_desc(ndr_desc);
 		ndbr_desc->enable = acpi_nfit_blk_region_enable;
 		ndbr_desc->do_io = acpi_desc->blk_do_io;
@@ -2682,8 +2725,7 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 		return 0;
 
 	if (spa->range_index == 0 && !nfit_spa_is_virtual(spa)) {
-		dev_dbg(acpi_desc->dev, "%s: detected invalid spa index\n",
-				__func__);
+		dev_dbg(acpi_desc->dev, "detected invalid spa index\n");
 		return 0;
 	}
 
@@ -2769,301 +2811,243 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
 	return rc;
 }
 
-static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc,
-		u32 max_ars)
+static int ars_status_alloc(struct acpi_nfit_desc *acpi_desc)
 {
 	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);
+	if (acpi_desc->ars_status) {
+		memset(acpi_desc->ars_status, 0, acpi_desc->max_ars);
 		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);
+	ars_status = devm_kzalloc(dev, acpi_desc->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_query_poison(struct acpi_nfit_desc *acpi_desc,
-		struct nfit_spa *nfit_spa)
+static int acpi_nfit_query_poison(struct acpi_nfit_desc *acpi_desc)
 {
-	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))
+	if (ars_status_alloc(acpi_desc))
 		return -ENOMEM;
 
 	rc = ars_get_status(acpi_desc);
+
 	if (rc < 0 && rc != -ENOSPC)
 		return rc;
 
-	if (ars_status_process_records(acpi_desc, acpi_desc->ars_status))
+	if (ars_status_process_records(acpi_desc))
 		return -ENOMEM;
 
 	return 0;
 }
 
-static void acpi_nfit_async_scrub(struct acpi_nfit_desc *acpi_desc,
-		struct nfit_spa *nfit_spa)
+static int ars_register(struct acpi_nfit_desc *acpi_desc, struct nfit_spa *nfit_spa,
+		int *query_rc)
 {
-	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;
+	int rc = *query_rc;
 
-	if (!nfit_spa->ars_required || !nfit_spa->nd_region)
-		return;
+	if (no_init_ars)
+		return acpi_nfit_register_region(acpi_desc, nfit_spa);
 
-	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;
-		}
+	set_bit(ARS_REQ, &nfit_spa->ars_state);
+	set_bit(ARS_SHORT, &nfit_spa->ars_state);
 
+	switch (rc) {
+	case 0:
+	case -EAGAIN:
+		rc = ars_start(acpi_desc, nfit_spa);
 		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);
+			*query_rc = rc;
 			break;
-		}
-
-		if (init_ars_len) {
-			ars_start = init_ars_start;
-			ars_len = init_ars_len;
+		} else if (rc == 0) {
+			rc = acpi_nfit_query_poison(acpi_desc);
 		} else {
-			ars_start = acpi_desc->ars_status->address;
-			ars_len = acpi_desc->ars_status->length;
+			set_bit(ARS_FAILED, &nfit_spa->ars_state);
+			break;
 		}
-		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);
+		if (rc == -EAGAIN)
+			clear_bit(ARS_SHORT, &nfit_spa->ars_state);
+		else if (rc == 0)
+			ars_complete(acpi_desc, nfit_spa);
 		break;
-	} while (1);
+	case -EBUSY:
+	case -ENOSPC:
+		break;
+	default:
+		set_bit(ARS_FAILED, &nfit_spa->ars_state);
+		break;
+	}
+
+	if (test_and_clear_bit(ARS_DONE, &nfit_spa->ars_state))
+		set_bit(ARS_REQ, &nfit_spa->ars_state);
+
+	return acpi_nfit_register_region(acpi_desc, nfit_spa);
 }
 
-static void acpi_nfit_scrub(struct work_struct *work)
+static void ars_complete_all(struct acpi_nfit_desc *acpi_desc)
 {
-	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. If we're called for a 'rescan', we harmlessly pass through
-	 * the first phase, but really only care about running phase 2, where
-	 * regions can be notified of new poison.
-	 */
 
-	/* process platform firmware initiated scrubs */
- retry:
-	mutex_lock(&acpi_desc->init_mutex);
 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
-		struct nd_cmd_ars_status *ars_status;
-		struct acpi_nfit_system_address *spa;
-		u64 ars_start, ars_len;
-		int rc;
-
-		if (acpi_desc->cancel)
-			break;
-
-		if (nfit_spa->nd_region)
+		if (test_bit(ARS_FAILED, &nfit_spa->ars_state))
 			continue;
+		ars_complete(acpi_desc, nfit_spa);
+	}
+}
 
-		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;
-			}
-		}
+static unsigned int __acpi_nfit_scrub(struct acpi_nfit_desc *acpi_desc,
+		int query_rc)
+{
+	unsigned int tmo = acpi_desc->scrub_tmo;
+	struct device *dev = acpi_desc->dev;
+	struct nfit_spa *nfit_spa;
 
-		if (rc < 0) {
-			/*
-			 * Initial scrub failed, we'll give it one more
-			 * try below...
-			 */
-			break;
-		}
+	if (acpi_desc->cancel)
+		return 0;
 
-		/* 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 (query_rc == -EBUSY) {
+		dev_dbg(dev, "ARS: ARS busy\n");
+		return min(30U * 60U, tmo * 2);
+	}
+	if (query_rc == -ENOSPC) {
+		dev_dbg(dev, "ARS: ARS continue\n");
+		ars_continue(acpi_desc);
+		return 1;
+	}
+	if (query_rc && query_rc != -EAGAIN) {
+		unsigned long long addr, end;
 
-		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);
+		addr = acpi_desc->ars_status->address;
+		end = addr + acpi_desc->ars_status->length;
+		dev_dbg(dev, "ARS: %llx-%llx failed (%d)\n", addr, end,
+				query_rc);
 	}
 
-	/*
-	 * 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.
-	 */
+	ars_complete_all(acpi_desc);
 	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_required = 1;
-			acpi_nfit_register_region(acpi_desc, nfit_spa);
+		if (test_bit(ARS_FAILED, &nfit_spa->ars_state))
+			continue;
+		if (test_bit(ARS_REQ, &nfit_spa->ars_state)) {
+			int rc = ars_start(acpi_desc, nfit_spa);
+
+			clear_bit(ARS_DONE, &nfit_spa->ars_state);
+			dev = nd_region_dev(nfit_spa->nd_region);
+			dev_dbg(dev, "ARS: range %d ARS start (%d)\n",
+					nfit_spa->spa->range_index, rc);
+			if (rc == 0 || rc == -EBUSY)
+				return 1;
+			dev_err(dev, "ARS: range %d ARS failed (%d)\n",
+					nfit_spa->spa->range_index, rc);
+			set_bit(ARS_FAILED, &nfit_spa->ars_state);
 		}
 	}
-	acpi_desc->init_complete = 1;
+	return 0;
+}
 
-	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
-		acpi_nfit_async_scrub(acpi_desc, nfit_spa);
-	acpi_desc->scrub_count++;
-	acpi_desc->ars_start_flags = 0;
-	if (acpi_desc->scrub_count_state)
-		sysfs_notify_dirent(acpi_desc->scrub_count_state);
+static void acpi_nfit_scrub(struct work_struct *work)
+{
+	struct acpi_nfit_desc *acpi_desc;
+	unsigned int tmo;
+	int query_rc;
+
+	acpi_desc = container_of(work, typeof(*acpi_desc), dwork.work);
+	mutex_lock(&acpi_desc->init_mutex);
+	query_rc = acpi_nfit_query_poison(acpi_desc);
+	tmo = __acpi_nfit_scrub(acpi_desc, query_rc);
+	if (tmo) {
+		queue_delayed_work(nfit_wq, &acpi_desc->dwork, tmo * HZ);
+		acpi_desc->scrub_tmo = tmo;
+	} else {
+		acpi_desc->scrub_count++;
+		if (acpi_desc->scrub_count_state)
+			sysfs_notify_dirent(acpi_desc->scrub_count_state);
+	}
+	memset(acpi_desc->ars_status, 0, acpi_desc->max_ars);
 	mutex_unlock(&acpi_desc->init_mutex);
 }
 
+static void acpi_nfit_init_ars(struct acpi_nfit_desc *acpi_desc,
+		struct nfit_spa *nfit_spa)
+{
+	int type = nfit_spa_type(nfit_spa->spa);
+	struct nd_cmd_ars_cap ars_cap;
+	int rc;
+
+	memset(&ars_cap, 0, sizeof(ars_cap));
+	rc = ars_get_cap(acpi_desc, &ars_cap, nfit_spa);
+	if (rc < 0)
+		return;
+	/* check that the supported scrub types match the spa type */
+	if (type == NFIT_SPA_VOLATILE && ((ars_cap.status >> 16)
+				& ND_ARS_VOLATILE) == 0)
+		return;
+	if (type == NFIT_SPA_PM && ((ars_cap.status >> 16)
+				& ND_ARS_PERSISTENT) == 0)
+		return;
+
+	nfit_spa->max_ars = ars_cap.max_ars_out;
+	nfit_spa->clear_err_unit = ars_cap.clear_err_unit;
+	acpi_desc->max_ars = max(nfit_spa->max_ars, acpi_desc->max_ars);
+	clear_bit(ARS_FAILED, &nfit_spa->ars_state);
+	set_bit(ARS_REQ, &nfit_spa->ars_state);
+}
+
 static int acpi_nfit_register_regions(struct acpi_nfit_desc *acpi_desc)
 {
 	struct nfit_spa *nfit_spa;
-	int rc;
+	int rc, query_rc;
+
+	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
+		set_bit(ARS_FAILED, &nfit_spa->ars_state);
+		switch (nfit_spa_type(nfit_spa->spa)) {
+		case NFIT_SPA_VOLATILE:
+		case NFIT_SPA_PM:
+			acpi_nfit_init_ars(acpi_desc, nfit_spa);
+			break;
+		}
+	}
+
+	/*
+	 * Reap any results that might be pending before starting new
+	 * short requests.
+	 */
+	query_rc = acpi_nfit_query_poison(acpi_desc);
+	if (query_rc == 0)
+		ars_complete_all(acpi_desc);
 
 	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 */
+		switch (nfit_spa_type(nfit_spa->spa)) {
+		case NFIT_SPA_VOLATILE:
+		case NFIT_SPA_PM:
+			/* register regions and kick off initial ARS run */
+			rc = ars_register(acpi_desc, nfit_spa, &query_rc);
+			if (rc)
+				return rc;
+			break;
+		case NFIT_SPA_BDW:
+			/* nothing to register */
+			break;
+		case NFIT_SPA_DCR:
+		case NFIT_SPA_VDISK:
+		case NFIT_SPA_VCD:
+		case NFIT_SPA_PDISK:
+		case NFIT_SPA_PCD:
+			/* register known regions that don't support ARS */
 			rc = acpi_nfit_register_region(acpi_desc, nfit_spa);
 			if (rc)
 				return rc;
+			break;
+		default:
+			/* don't register unknown regions */
+			break;
 		}
 
-	acpi_desc->ars_start_flags = 0;
-	if (!acpi_desc->cancel)
-		queue_work(nfit_wq, &acpi_desc->work);
+	queue_delayed_work(nfit_wq, &acpi_desc->dwork, 0);
 	return 0;
 }
 
@@ -3173,8 +3157,7 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz)
 		data = add_table(acpi_desc, &prev, data, end);
 
 	if (IS_ERR(data)) {
-		dev_dbg(dev, "%s: nfit table parsing error: %ld\n", __func__,
-				PTR_ERR(data));
+		dev_dbg(dev, "nfit table parsing error: %ld\n",	PTR_ERR(data));
 		rc = PTR_ERR(data);
 		goto out_unlock;
 	}
@@ -3199,49 +3182,20 @@ int acpi_nfit_init(struct acpi_nfit_desc *acpi_desc, void *data, acpi_size sz)
 }
 EXPORT_SYMBOL_GPL(acpi_nfit_init);
 
-struct acpi_nfit_flush_work {
-	struct work_struct work;
-	struct completion cmp;
-};
-
-static void flush_probe(struct work_struct *work)
-{
-	struct acpi_nfit_flush_work *flush;
-
-	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;
-	int rc;
 
-	/* bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */
+	/* Bounce the device lock to flush acpi_nfit_add / acpi_nfit_notify */
 	device_lock(dev);
 	device_unlock(dev);
 
-	/* bounce the init_mutex to make init_complete valid */
+	/* Bounce the init_mutex to complete initial registration */
 	mutex_lock(&acpi_desc->init_mutex);
-	if (acpi_desc->cancel || acpi_desc->init_complete) {
-		mutex_unlock(&acpi_desc->init_mutex);
-		return 0;
-	}
-
-	/*
-	 * 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);
-	init_completion(&flush.cmp);
-	queue_work(nfit_wq, &flush.work);
 	mutex_unlock(&acpi_desc->init_mutex);
 
-	rc = wait_for_completion_interruptible(&flush.cmp);
-	cancel_work_sync(&flush.work);
-	return rc;
+	return 0;
 }
 
 static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
@@ -3260,20 +3214,18 @@ static int acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
 	 * just needs guarantees that any ars it initiates are not
 	 * interrupted by any intervening start reqeusts from userspace.
 	 */
-	if (work_busy(&acpi_desc->work))
+	if (work_busy(&acpi_desc->dwork.work))
 		return -EBUSY;
 
 	return 0;
 }
 
-int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc, u8 flags)
+int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc, unsigned long flags)
 {
 	struct device *dev = acpi_desc->dev;
+	int scheduled = 0, busy = 0;
 	struct nfit_spa *nfit_spa;
 
-	if (work_busy(&acpi_desc->work))
-		return -EBUSY;
-
 	mutex_lock(&acpi_desc->init_mutex);
 	if (acpi_desc->cancel) {
 		mutex_unlock(&acpi_desc->init_mutex);
@@ -3281,19 +3233,32 @@ int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc, u8 flags)
 	}
 
 	list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
-		struct acpi_nfit_system_address *spa = nfit_spa->spa;
+		int type = nfit_spa_type(nfit_spa->spa);
 
-		if (nfit_spa_type(spa) != NFIT_SPA_PM)
+		if (type != NFIT_SPA_PM && type != NFIT_SPA_VOLATILE)
+			continue;
+		if (test_bit(ARS_FAILED, &nfit_spa->ars_state))
 			continue;
 
-		nfit_spa->ars_required = 1;
+		if (test_and_set_bit(ARS_REQ, &nfit_spa->ars_state))
+			busy++;
+		else {
+			if (test_bit(ARS_SHORT, &flags))
+				set_bit(ARS_SHORT, &nfit_spa->ars_state);
+			scheduled++;
+		}
+	}
+	if (scheduled) {
+		queue_delayed_work(nfit_wq, &acpi_desc->dwork, 0);
+		dev_dbg(dev, "ars_scan triggered\n");
 	}
-	acpi_desc->ars_start_flags = flags;
-	queue_work(nfit_wq, &acpi_desc->work);
-	dev_dbg(dev, "%s: ars_scan triggered\n", __func__);
 	mutex_unlock(&acpi_desc->init_mutex);
 
-	return 0;
+	if (scheduled)
+		return 0;
+	if (busy)
+		return -EBUSY;
+	return -ENOTTY;
 }
 
 void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
@@ -3320,7 +3285,8 @@ void acpi_nfit_desc_init(struct acpi_nfit_desc *acpi_desc, struct device *dev)
 	INIT_LIST_HEAD(&acpi_desc->dimms);
 	INIT_LIST_HEAD(&acpi_desc->list);
 	mutex_init(&acpi_desc->init_mutex);
-	INIT_WORK(&acpi_desc->work, acpi_nfit_scrub);
+	acpi_desc->scrub_tmo = 1;
+	INIT_DELAYED_WORK(&acpi_desc->dwork, acpi_nfit_scrub);
 }
 EXPORT_SYMBOL_GPL(acpi_nfit_desc_init);
 
@@ -3344,6 +3310,7 @@ void acpi_nfit_shutdown(void *data)
 
 	mutex_lock(&acpi_desc->init_mutex);
 	acpi_desc->cancel = 1;
+	cancel_delayed_work_sync(&acpi_desc->dwork);
 	mutex_unlock(&acpi_desc->init_mutex);
 
 	/*
@@ -3397,8 +3364,8 @@ static int acpi_nfit_add(struct acpi_device *adev)
 			rc = acpi_nfit_init(acpi_desc, obj->buffer.pointer,
 					obj->buffer.length);
 		else
-			dev_dbg(dev, "%s invalid type %d, ignoring _FIT\n",
-				 __func__, (int) obj->type);
+			dev_dbg(dev, "invalid type %d, ignoring _FIT\n",
+				(int) obj->type);
 		kfree(buf.pointer);
 	} else
 		/* skip over the lead-in header table */
@@ -3427,7 +3394,7 @@ static void acpi_nfit_update_notify(struct device *dev, acpi_handle handle)
 
 	if (!dev->driver) {
 		/* dev->driver may be null if we're being removed */
-		dev_dbg(dev, "%s: no driver found for dev\n", __func__);
+		dev_dbg(dev, "no driver found for dev\n");
 		return;
 	}
 
@@ -3465,15 +3432,15 @@ static void acpi_nfit_update_notify(struct device *dev, acpi_handle handle)
 static void acpi_nfit_uc_error_notify(struct device *dev, acpi_handle handle)
 {
 	struct acpi_nfit_desc *acpi_desc = dev_get_drvdata(dev);
-	u8 flags = (acpi_desc->scrub_mode == HW_ERROR_SCRUB_ON) ?
-			0 : ND_ARS_RETURN_PREV_DATA;
+	unsigned long flags = (acpi_desc->scrub_mode == HW_ERROR_SCRUB_ON) ?
+			0 : 1 << ARS_SHORT;
 
 	acpi_nfit_ars_rescan(acpi_desc, flags);
 }
 
 void __acpi_nfit_notify(struct device *dev, acpi_handle handle, u32 event)
 {
-	dev_dbg(dev, "%s: event: 0x%x\n", __func__, event);
+	dev_dbg(dev, "event: 0x%x\n", event);
 
 	switch (event) {
 	case NFIT_NOTIFY_UPDATE:
diff --git a/drivers/acpi/nfit/mce.c b/drivers/acpi/nfit/mce.c
index b92921439657..e9626bf6ca29 100644
--- a/drivers/acpi/nfit/mce.c
+++ b/drivers/acpi/nfit/mce.c
@@ -51,9 +51,8 @@ static int nfit_handle_mce(struct notifier_block *nb, unsigned long val,
 			if ((spa->address + spa->length - 1) < mce->addr)
 				continue;
 			found_match = 1;
-			dev_dbg(dev, "%s: addr in SPA %d (0x%llx, 0x%llx)\n",
-				__func__, spa->range_index, spa->address,
-				spa->length);
+			dev_dbg(dev, "addr in SPA %d (0x%llx, 0x%llx)\n",
+				spa->range_index, spa->address, spa->length);
 			/*
 			 * We can break at the first match because we're going
 			 * to rescan all the SPA ranges. There shouldn't be any
diff --git a/drivers/acpi/nfit/nfit.h b/drivers/acpi/nfit/nfit.h
index 50d36e166d70..7d15856a739f 100644
--- a/drivers/acpi/nfit/nfit.h
+++ b/drivers/acpi/nfit/nfit.h
@@ -117,10 +117,17 @@ enum nfit_dimm_notifiers {
 	NFIT_NOTIFY_DIMM_HEALTH = 0x81,
 };
 
+enum nfit_ars_state {
+	ARS_REQ,
+	ARS_DONE,
+	ARS_SHORT,
+	ARS_FAILED,
+};
+
 struct nfit_spa {
 	struct list_head list;
 	struct nd_region *nd_region;
-	unsigned int ars_required:1;
+	unsigned long ars_state;
 	u32 clear_err_unit;
 	u32 max_ars;
 	struct acpi_nfit_system_address spa[0];
@@ -171,9 +178,8 @@ struct nfit_mem {
 	struct resource *flush_wpq;
 	unsigned long dsm_mask;
 	int family;
-	u32 has_lsi:1;
-	u32 has_lsr:1;
-	u32 has_lsw:1;
+	bool has_lsr;
+	bool has_lsw;
 };
 
 struct acpi_nfit_desc {
@@ -191,18 +197,18 @@ struct acpi_nfit_desc {
 	struct device *dev;
 	u8 ars_start_flags;
 	struct nd_cmd_ars_status *ars_status;
-	size_t ars_status_size;
-	struct work_struct work;
+	struct delayed_work dwork;
 	struct list_head list;
 	struct kernfs_node *scrub_count_state;
+	unsigned int max_ars;
 	unsigned int scrub_count;
 	unsigned int scrub_mode;
 	unsigned int cancel:1;
-	unsigned int init_complete:1;
 	unsigned long dimm_cmd_force_en;
 	unsigned long bus_cmd_force_en;
 	unsigned long bus_nfit_cmd_force_en;
 	unsigned int platform_cap;
+	unsigned int scrub_tmo;
 	int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
 			void *iobuf, u64 len, int rw);
 };
@@ -244,7 +250,7 @@ struct nfit_blk {
 
 extern struct list_head acpi_descs;
 extern struct mutex acpi_desc_lock;
-int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc, u8 flags);
+int acpi_nfit_ars_rescan(struct acpi_nfit_desc *acpi_desc, unsigned long flags);
 
 #ifdef CONFIG_X86_MCE
 void nfit_mce_register(void);
diff --git a/drivers/dax/Kconfig b/drivers/dax/Kconfig
index b79aa8f7a497..e0700bf4893a 100644
--- a/drivers/dax/Kconfig
+++ b/drivers/dax/Kconfig
@@ -1,3 +1,7 @@
+config DAX_DRIVER
+	select DAX
+	bool
+
 menuconfig DAX
 	tristate "DAX: direct access to differentiated memory"
 	select SRCU
@@ -16,7 +20,6 @@ config DEV_DAX
 	  baseline memory pool.  Mappings of a /dev/daxX.Y device impose
 	  restrictions that make the mapping behavior deterministic.
 
-
 config DEV_DAX_PMEM
 	tristate "PMEM DAX: direct access to persistent memory"
 	depends on LIBNVDIMM && NVDIMM_DAX && DEV_DAX
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 0b61f48f21a6..be8606457f27 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -257,8 +257,8 @@ static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
 	dax_region = dev_dax->region;
 	if (dax_region->align > PAGE_SIZE) {
-		dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
-			__func__, dax_region->align, fault_size);
+		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
+			dax_region->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -267,8 +267,7 @@ static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
 	phys = dax_pgoff_to_phys(dev_dax, vmf->pgoff, PAGE_SIZE);
 	if (phys == -1) {
-		dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
-				vmf->pgoff);
+		dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", vmf->pgoff);
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -299,14 +298,14 @@ static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
 	dax_region = dev_dax->region;
 	if (dax_region->align > PMD_SIZE) {
-		dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
-			__func__, dax_region->align, fault_size);
+		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
+			dax_region->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
 	/* dax pmd mappings require pfn_t_devmap() */
 	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-		dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
+		dev_dbg(dev, "region lacks devmap flags\n");
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -323,8 +322,7 @@ static int __dev_dax_pmd_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 	pgoff = linear_page_index(vmf->vma, pmd_addr);
 	phys = dax_pgoff_to_phys(dev_dax, pgoff, PMD_SIZE);
 	if (phys == -1) {
-		dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
-				pgoff);
+		dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -351,14 +349,14 @@ static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 
 	dax_region = dev_dax->region;
 	if (dax_region->align > PUD_SIZE) {
-		dev_dbg(dev, "%s: alignment (%#x) > fault size (%#x)\n",
-			__func__, dax_region->align, fault_size);
+		dev_dbg(dev, "alignment (%#x) > fault size (%#x)\n",
+			dax_region->align, fault_size);
 		return VM_FAULT_SIGBUS;
 	}
 
 	/* dax pud mappings require pfn_t_devmap() */
 	if ((dax_region->pfn_flags & (PFN_DEV|PFN_MAP)) != (PFN_DEV|PFN_MAP)) {
-		dev_dbg(dev, "%s: region lacks devmap flags\n", __func__);
+		dev_dbg(dev, "region lacks devmap flags\n");
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -375,8 +373,7 @@ static int __dev_dax_pud_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
 	pgoff = linear_page_index(vmf->vma, pud_addr);
 	phys = dax_pgoff_to_phys(dev_dax, pgoff, PUD_SIZE);
 	if (phys == -1) {
-		dev_dbg(dev, "%s: pgoff_to_phys(%#lx) failed\n", __func__,
-				pgoff);
+		dev_dbg(dev, "pgoff_to_phys(%#lx) failed\n", pgoff);
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -399,9 +396,8 @@ static int dev_dax_huge_fault(struct vm_fault *vmf,
 	struct file *filp = vmf->vma->vm_file;
 	struct dev_dax *dev_dax = filp->private_data;
 
-	dev_dbg(&dev_dax->dev, "%s: %s: %s (%#lx - %#lx) size = %d\n", __func__,
-			current->comm, (vmf->flags & FAULT_FLAG_WRITE)
-			? "write" : "read",
+	dev_dbg(&dev_dax->dev, "%s: %s (%#lx - %#lx) size = %d\n", current->comm,
+			(vmf->flags & FAULT_FLAG_WRITE) ? "write" : "read",
 			vmf->vma->vm_start, vmf->vma->vm_end, pe_size);
 
 	id = dax_read_lock();
@@ -460,7 +456,7 @@ static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
 	struct dev_dax *dev_dax = filp->private_data;
 	int rc, id;
 
-	dev_dbg(&dev_dax->dev, "%s\n", __func__);
+	dev_dbg(&dev_dax->dev, "trace\n");
 
 	/*
 	 * We lock to check dax_dev liveness and will re-check at
@@ -518,7 +514,7 @@ static int dax_open(struct inode *inode, struct file *filp)
 	struct inode *__dax_inode = dax_inode(dax_dev);
 	struct dev_dax *dev_dax = dax_get_private(dax_dev);
 
-	dev_dbg(&dev_dax->dev, "%s\n", __func__);
+	dev_dbg(&dev_dax->dev, "trace\n");
 	inode->i_mapping = __dax_inode->i_mapping;
 	inode->i_mapping->host = __dax_inode;
 	filp->f_mapping = inode->i_mapping;
@@ -533,7 +529,7 @@ static int dax_release(struct inode *inode, struct file *filp)
 {
 	struct dev_dax *dev_dax = filp->private_data;
 
-	dev_dbg(&dev_dax->dev, "%s\n", __func__);
+	dev_dbg(&dev_dax->dev, "trace\n");
 	return 0;
 }
 
@@ -575,7 +571,7 @@ static void unregister_dev_dax(void *dev)
 	struct inode *inode = dax_inode(dax_dev);
 	struct cdev *cdev = inode->i_cdev;
 
-	dev_dbg(dev, "%s\n", __func__);
+	dev_dbg(dev, "trace\n");
 
 	kill_dev_dax(dev_dax);
 	cdev_device_del(cdev, dev);
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index 31b6ecce4c64..fd49b24fd6af 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -34,7 +34,7 @@ static void dax_pmem_percpu_release(struct percpu_ref *ref)
 {
 	struct dax_pmem *dax_pmem = to_dax_pmem(ref);
 
-	dev_dbg(dax_pmem->dev, "%s\n", __func__);
+	dev_dbg(dax_pmem->dev, "trace\n");
 	complete(&dax_pmem->cmp);
 }
 
@@ -43,7 +43,7 @@ static void dax_pmem_percpu_exit(void *data)
 	struct percpu_ref *ref = data;
 	struct dax_pmem *dax_pmem = to_dax_pmem(ref);
 
-	dev_dbg(dax_pmem->dev, "%s\n", __func__);
+	dev_dbg(dax_pmem->dev, "trace\n");
 	wait_for_completion(&dax_pmem->cmp);
 	percpu_ref_exit(ref);
 }
@@ -53,7 +53,7 @@ static void dax_pmem_percpu_kill(void *data)
 	struct percpu_ref *ref = data;
 	struct dax_pmem *dax_pmem = to_dax_pmem(ref);
 
-	dev_dbg(dax_pmem->dev, "%s\n", __func__);
+	dev_dbg(dax_pmem->dev, "trace\n");
 	percpu_ref_kill(ref);
 }
 
@@ -150,17 +150,7 @@ static struct nd_device_driver dax_pmem_driver = {
 	.type = ND_DRIVER_DAX_PMEM,
 };
 
-static int __init dax_pmem_init(void)
-{
-	return nd_driver_register(&dax_pmem_driver);
-}
-module_init(dax_pmem_init);
-
-static void __exit dax_pmem_exit(void)
-{
-	driver_unregister(&dax_pmem_driver.drv);
-}
-module_exit(dax_pmem_exit);
+module_nd_driver(dax_pmem_driver);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Intel Corporation");
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index ecdc292aa4e4..2b2332b605e4 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -124,10 +124,19 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
 		return len < 0 ? len : -EIO;
 	}
 
-	if ((IS_ENABLED(CONFIG_FS_DAX_LIMITED) && pfn_t_special(pfn))
-			|| pfn_t_devmap(pfn))
+	if (IS_ENABLED(CONFIG_FS_DAX_LIMITED) && pfn_t_special(pfn)) {
+		/*
+		 * An arch that has enabled the pmem api should also
+		 * have its drivers support pfn_t_devmap()
+		 *
+		 * This is a developer warning and should not trigger in
+		 * production. dax_flush() will crash since it depends
+		 * on being able to do (page_address(pfn_to_page())).
+		 */
+		WARN_ON(IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API));
+	} else if (pfn_t_devmap(pfn)) {
 		/* pass */;
-	else {
+	} else {
 		pr_debug("VFS (%s): error: dax support not enabled\n",
 				sb->s_id);
 		return -EOPNOTSUPP;
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 2c8ac3688815..edff083f7c4e 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -201,7 +201,7 @@ config BLK_DEV_DM_BUILTIN
 config BLK_DEV_DM
 	tristate "Device mapper support"
 	select BLK_DEV_DM_BUILTIN
-	select DAX
+	depends on DAX || DAX=n
 	---help---
 	  Device-mapper is a low level volume manager.  It works by allowing
 	  people to specify mappings for ranges of logical sectors.  Various
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 99297212eeec..775c06d953b7 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -154,6 +154,7 @@ static int linear_iterate_devices(struct dm_target *ti,
 	return fn(ti, lc->dev, lc->start, ti->len, data);
 }
 
+#if IS_ENABLED(CONFIG_DAX_DRIVER)
 static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn)
 {
@@ -184,6 +185,11 @@ static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
 	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
 }
 
+#else
+#define linear_dax_direct_access NULL
+#define linear_dax_copy_from_iter NULL
+#endif
+
 static struct target_type linear_target = {
 	.name   = "linear",
 	.version = {1, 4, 0},
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 9de072b7782a..c90c7c08a77f 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -611,51 +611,6 @@ static int log_mark(struct log_writes_c *lc, char *data)
 	return 0;
 }
 
-static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes,
-		   struct iov_iter *i)
-{
-	struct pending_block *block;
-
-	if (!bytes)
-		return 0;
-
-	block = kzalloc(sizeof(struct pending_block), GFP_KERNEL);
-	if (!block) {
-		DMERR("Error allocating dax pending block");
-		return -ENOMEM;
-	}
-
-	block->data = kzalloc(bytes, GFP_KERNEL);
-	if (!block->data) {
-		DMERR("Error allocating dax data space");
-		kfree(block);
-		return -ENOMEM;
-	}
-
-	/* write data provided via the iterator */
-	if (!copy_from_iter(block->data, bytes, i)) {
-		DMERR("Error copying dax data");
-		kfree(block->data);
-		kfree(block);
-		return -EIO;
-	}
-
-	/* rewind the iterator so that the block driver can use it */
-	iov_iter_revert(i, bytes);
-
-	block->datalen = bytes;
-	block->sector = bio_to_dev_sectors(lc, sector);
-	block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift;
-
-	atomic_inc(&lc->pending_blocks);
-	spin_lock_irq(&lc->blocks_lock);
-	list_add_tail(&block->list, &lc->unflushed_blocks);
-	spin_unlock_irq(&lc->blocks_lock);
-	wake_up_process(lc->log_kthread);
-
-	return 0;
-}
-
 static void log_writes_dtr(struct dm_target *ti)
 {
 	struct log_writes_c *lc = ti->private;
@@ -925,6 +880,52 @@ static void log_writes_io_hints(struct dm_target *ti, struct queue_limits *limit
 	limits->io_min = limits->physical_block_size;
 }
 
+#if IS_ENABLED(CONFIG_DAX_DRIVER)
+static int log_dax(struct log_writes_c *lc, sector_t sector, size_t bytes,
+		   struct iov_iter *i)
+{
+	struct pending_block *block;
+
+	if (!bytes)
+		return 0;
+
+	block = kzalloc(sizeof(struct pending_block), GFP_KERNEL);
+	if (!block) {
+		DMERR("Error allocating dax pending block");
+		return -ENOMEM;
+	}
+
+	block->data = kzalloc(bytes, GFP_KERNEL);
+	if (!block->data) {
+		DMERR("Error allocating dax data space");
+		kfree(block);
+		return -ENOMEM;
+	}
+
+	/* write data provided via the iterator */
+	if (!copy_from_iter(block->data, bytes, i)) {
+		DMERR("Error copying dax data");
+		kfree(block->data);
+		kfree(block);
+		return -EIO;
+	}
+
+	/* rewind the iterator so that the block driver can use it */
+	iov_iter_revert(i, bytes);
+
+	block->datalen = bytes;
+	block->sector = bio_to_dev_sectors(lc, sector);
+	block->nr_sectors = ALIGN(bytes, lc->sectorsize) >> lc->sectorshift;
+
+	atomic_inc(&lc->pending_blocks);
+	spin_lock_irq(&lc->blocks_lock);
+	list_add_tail(&block->list, &lc->unflushed_blocks);
+	spin_unlock_irq(&lc->blocks_lock);
+	wake_up_process(lc->log_kthread);
+
+	return 0;
+}
+
 static long log_writes_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 					 long nr_pages, void **kaddr, pfn_t *pfn)
 {
@@ -961,6 +962,10 @@ static size_t log_writes_dax_copy_from_iter(struct dm_target *ti,
 dax_copy:
 	return dax_copy_from_iter(lc->dev->dax_dev, pgoff, addr, bytes, i);
 }
+#else
+#define log_writes_dax_direct_access NULL
+#define log_writes_dax_copy_from_iter NULL
+#endif
 
 static struct target_type log_writes_target = {
 	.name   = "log-writes",
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index bb907cb3e60d..fe7fb9b1aec3 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -313,6 +313,7 @@ static int stripe_map(struct dm_target *ti, struct bio *bio)
 	return DM_MAPIO_REMAPPED;
 }
 
+#if IS_ENABLED(CONFIG_DAX_DRIVER)
 static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn)
 {
@@ -353,6 +354,11 @@ static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
 	return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
 }
 
+#else
+#define stripe_dax_direct_access NULL
+#define stripe_dax_copy_from_iter NULL
+#endif
+
 /*
  * Stripe status:
  *
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 5a81c47be4e4..4ea404dbcf0b 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1826,7 +1826,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
 static struct mapped_device *alloc_dev(int minor)
 {
 	int r, numa_node_id = dm_get_numa_node();
-	struct dax_device *dax_dev;
+	struct dax_device *dax_dev = NULL;
 	struct mapped_device *md;
 	void *old_md;
 
@@ -1892,9 +1892,11 @@ static struct mapped_device *alloc_dev(int minor)
 	md->disk->private_data = md;
 	sprintf(md->disk->disk_name, "dm-%d", minor);
 
-	dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
-	if (!dax_dev)
-		goto bad;
+	if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
+		dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
+		if (!dax_dev)
+			goto bad;
+	}
 	md->dax_dev = dax_dev;
 
 	add_disk_no_queue_reg(md->disk);
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index a65f2e1d9f53..85997184e047 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -20,7 +20,7 @@ if LIBNVDIMM
 config BLK_DEV_PMEM
 	tristate "PMEM: Persistent memory block device support"
 	default LIBNVDIMM
-	select DAX
+	select DAX_DRIVER
 	select ND_BTT if BTT
 	select ND_PFN if NVDIMM_PFN
 	help
@@ -102,4 +102,15 @@ config NVDIMM_DAX
 
 	  Select Y if unsure
 
+config OF_PMEM
+	# FIXME: make tristate once OF_NUMA dependency removed
+	bool "Device-tree support for persistent memory regions"
+	depends on OF
+	default LIBNVDIMM
+	help
+	  Allows regions of persistent memory to be described in the
+	  device-tree.
+
+	  Select Y if unsure.
+
 endif
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 70d5f3ad9909..e8847045dac0 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o
 obj-$(CONFIG_ND_BTT) += nd_btt.o
 obj-$(CONFIG_ND_BLK) += nd_blk.o
 obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
+obj-$(CONFIG_OF_PMEM) += of_pmem.o
 
 nd_pmem-y := pmem.o
 
diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index d58925295aa7..795ad4ff35ca 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -26,7 +26,7 @@ static void nd_btt_release(struct device *dev)
 	struct nd_region *nd_region = to_nd_region(dev->parent);
 	struct nd_btt *nd_btt = to_nd_btt(dev);
 
-	dev_dbg(dev, "%s\n", __func__);
+	dev_dbg(dev, "trace\n");
 	nd_detach_ndns(&nd_btt->dev, &nd_btt->ndns);
 	ida_simple_remove(&nd_region->btt_ida, nd_btt->id);
 	kfree(nd_btt->uuid);
@@ -74,8 +74,8 @@ static ssize_t sector_size_store(struct device *dev,
 	nvdimm_bus_lock(dev);
 	rc = nd_size_select_store(dev, buf, &nd_btt->lbasize,
 			btt_lbasize_supported);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -101,8 +101,8 @@ static ssize_t uuid_store(struct device *dev,
 
 	device_lock(dev);
 	rc = nd_uuid_store(dev, &nd_btt->uuid, buf, len);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	device_unlock(dev);
 
 	return rc ? rc : len;
@@ -131,8 +131,8 @@ static ssize_t namespace_store(struct device *dev,
 	device_lock(dev);
 	nvdimm_bus_lock(dev);
 	rc = nd_namespace_store(dev, &nd_btt->ndns, buf, len);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -206,8 +206,8 @@ static struct device *__nd_btt_create(struct nd_region *nd_region,
 	dev->groups = nd_btt_attribute_groups;
 	device_initialize(&nd_btt->dev);
 	if (ndns && !__nd_attach_ndns(&nd_btt->dev, ndns, &nd_btt->ndns)) {
-		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
-				__func__, dev_name(ndns->claim));
+		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
+				dev_name(ndns->claim));
 		put_device(dev);
 		return NULL;
 	}
@@ -346,8 +346,7 @@ int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
 		return -ENOMEM;
 	btt_sb = devm_kzalloc(dev, sizeof(*btt_sb), GFP_KERNEL);
 	rc = __nd_btt_probe(to_nd_btt(btt_dev), ndns, btt_sb);
-	dev_dbg(dev, "%s: btt: %s\n", __func__,
-			rc == 0 ? dev_name(btt_dev) : "<none>");
+	dev_dbg(dev, "btt: %s\n", rc == 0 ? dev_name(btt_dev) : "<none>");
 	if (rc < 0) {
 		struct nd_btt *nd_btt = to_nd_btt(btt_dev);
 
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 78eabc3a1ab1..a64023690cad 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -358,6 +358,7 @@ struct nvdimm_bus *nvdimm_bus_register(struct device *parent,
 	nvdimm_bus->dev.release = nvdimm_bus_release;
 	nvdimm_bus->dev.groups = nd_desc->attr_groups;
 	nvdimm_bus->dev.bus = &nvdimm_bus_type;
+	nvdimm_bus->dev.of_node = nd_desc->of_node;
 	dev_set_name(&nvdimm_bus->dev, "ndbus%d", nvdimm_bus->id);
 	rc = device_register(&nvdimm_bus->dev);
 	if (rc) {
@@ -984,8 +985,8 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 
 	if (cmd == ND_CMD_CALL) {
 		func = pkg.nd_command;
-		dev_dbg(dev, "%s:%s, idx: %llu, in: %u, out: %u, len %llu\n",
-				__func__, dimm_name, pkg.nd_command,
+		dev_dbg(dev, "%s, idx: %llu, in: %u, out: %u, len %llu\n",
+				dimm_name, pkg.nd_command,
 				in_len, out_len, buf_len);
 	}
 
@@ -996,8 +997,8 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 		u32 copy;
 
 		if (out_size == UINT_MAX) {
-			dev_dbg(dev, "%s:%s unknown output size cmd: %s field: %d\n",
-					__func__, dimm_name, cmd_name, i);
+			dev_dbg(dev, "%s unknown output size cmd: %s field: %d\n",
+					dimm_name, cmd_name, i);
 			return -EFAULT;
 		}
 		if (out_len < sizeof(out_env))
@@ -1012,9 +1013,8 @@ static int __nd_ioctl(struct nvdimm_bus *nvdimm_bus, struct nvdimm *nvdimm,
 
 	buf_len = (u64) out_len + (u64) in_len;
 	if (buf_len > ND_IOCTL_MAX_BUFLEN) {
-		dev_dbg(dev, "%s:%s cmd: %s buf_len: %llu > %d\n", __func__,
-				dimm_name, cmd_name, buf_len,
-				ND_IOCTL_MAX_BUFLEN);
+		dev_dbg(dev, "%s cmd: %s buf_len: %llu > %d\n", dimm_name,
+				cmd_name, buf_len, ND_IOCTL_MAX_BUFLEN);
 		return -EINVAL;
 	}
 
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index b2fc29b8279b..30852270484f 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -148,7 +148,7 @@ ssize_t nd_namespace_store(struct device *dev,
 	char *name;
 
 	if (dev->driver) {
-		dev_dbg(dev, "%s: -EBUSY\n", __func__);
+		dev_dbg(dev, "namespace already active\n");
 		return -EBUSY;
 	}
 
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 1dc527660637..acce050856a8 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -134,7 +134,7 @@ static void nvdimm_map_release(struct kref *kref)
 	nvdimm_map = container_of(kref, struct nvdimm_map, kref);
 	nvdimm_bus = nvdimm_map->nvdimm_bus;
 
-	dev_dbg(&nvdimm_bus->dev, "%s: %pa\n", __func__, &nvdimm_map->offset);
+	dev_dbg(&nvdimm_bus->dev, "%pa\n", &nvdimm_map->offset);
 	list_del(&nvdimm_map->list);
 	if (nvdimm_map->flags)
 		memunmap(nvdimm_map->mem);
@@ -230,8 +230,8 @@ static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
 
 	for (i = 0; i < 16; i++) {
 		if (!isxdigit(str[0]) || !isxdigit(str[1])) {
-			dev_dbg(dev, "%s: pos: %d buf[%zd]: %c buf[%zd]: %c\n",
-					__func__, i, str - buf, str[0],
+			dev_dbg(dev, "pos: %d buf[%zd]: %c buf[%zd]: %c\n",
+					i, str - buf, str[0],
 					str + 1 - buf, str[1]);
 			return -EINVAL;
 		}
diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 1bf2bd318371..0453f49dc708 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -24,7 +24,7 @@ static void nd_dax_release(struct device *dev)
 	struct nd_dax *nd_dax = to_nd_dax(dev);
 	struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
 
-	dev_dbg(dev, "%s\n", __func__);
+	dev_dbg(dev, "trace\n");
 	nd_detach_ndns(dev, &nd_pfn->ndns);
 	ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
 	kfree(nd_pfn->uuid);
@@ -129,8 +129,7 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 	pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
 	nd_pfn->pfn_sb = pfn_sb;
 	rc = nd_pfn_validate(nd_pfn, DAX_SIG);
-	dev_dbg(dev, "%s: dax: %s\n", __func__,
-			rc == 0 ? dev_name(dax_dev) : "<none>");
+	dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
 	if (rc < 0) {
 		nd_detach_ndns(dax_dev, &nd_pfn->ndns);
 		put_device(dax_dev);
diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
index f8913b8124b6..233907889f96 100644
--- a/drivers/nvdimm/dimm.c
+++ b/drivers/nvdimm/dimm.c
@@ -67,9 +67,11 @@ static int nvdimm_probe(struct device *dev)
 	ndd->ns_next = nd_label_next_nsindex(ndd->ns_current);
 	nd_label_copy(ndd, to_next_namespace_index(ndd),
 			to_current_namespace_index(ndd));
-	rc = nd_label_reserve_dpa(ndd);
-	if (ndd->ns_current >= 0)
-		nvdimm_set_aliasing(dev);
+	if (ndd->ns_current >= 0) {
+		rc = nd_label_reserve_dpa(ndd);
+		if (rc == 0)
+			nvdimm_set_aliasing(dev);
+	}
 	nvdimm_clear_locked(dev);
 	nvdimm_bus_unlock(dev);
 
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 097794d9f786..e00d45522b80 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -131,7 +131,7 @@ int nvdimm_init_config_data(struct nvdimm_drvdata *ndd)
 		}
 		memcpy(ndd->data + offset, cmd->out_buf, cmd->in_length);
 	}
-	dev_dbg(ndd->dev, "%s: len: %zu rc: %d\n", __func__, offset, rc);
+	dev_dbg(ndd->dev, "len: %zu rc: %d\n", offset, rc);
 	kfree(cmd);
 
 	return rc;
@@ -266,8 +266,7 @@ void nvdimm_drvdata_release(struct kref *kref)
 	struct device *dev = ndd->dev;
 	struct resource *res, *_r;
 
-	dev_dbg(dev, "%s\n", __func__);
-
+	dev_dbg(dev, "trace\n");
 	nvdimm_bus_lock(dev);
 	for_each_dpa_resource_safe(ndd, res, _r)
 		nvdimm_free_dpa(ndd, res);
@@ -660,7 +659,7 @@ int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count)
 	nd_synchronize();
 
 	device_for_each_child(&nvdimm_bus->dev, &count, count_dimms);
-	dev_dbg(&nvdimm_bus->dev, "%s: count: %d\n", __func__, count);
+	dev_dbg(&nvdimm_bus->dev, "count: %d\n", count);
 	if (count != dimm_count)
 		return -ENXIO;
 	return 0;
diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index de66c02f6140..1d28cd656536 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -45,9 +45,27 @@ unsigned sizeof_namespace_label(struct nvdimm_drvdata *ndd)
 	return ndd->nslabel_size;
 }
 
+static size_t __sizeof_namespace_index(u32 nslot)
+{
+	return ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),
+			NSINDEX_ALIGN);
+}
+
+static int __nvdimm_num_label_slots(struct nvdimm_drvdata *ndd,
+		size_t index_size)
+{
+	return (ndd->nsarea.config_size - index_size * 2) /
+			sizeof_namespace_label(ndd);
+}
+
 int nvdimm_num_label_slots(struct nvdimm_drvdata *ndd)
 {
-	return ndd->nsarea.config_size / (sizeof_namespace_label(ndd) + 1);
+	u32 tmp_nslot, n;
+
+	tmp_nslot = ndd->nsarea.config_size / sizeof_namespace_label(ndd);
+	n = __sizeof_namespace_index(tmp_nslot) / NSINDEX_ALIGN;
+
+	return __nvdimm_num_label_slots(ndd, NSINDEX_ALIGN * n);
 }
 
 size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
@@ -55,18 +73,14 @@ size_t sizeof_namespace_index(struct nvdimm_drvdata *ndd)
 	u32 nslot, space, size;
 
 	/*
-	 * The minimum index space is 512 bytes, with that amount of
-	 * index we can describe ~1400 labels which is less than a byte
-	 * of overhead per label.  Round up to a byte of overhead per
-	 * label and determine the size of the index region.  Yes, this
-	 * starts to waste space at larger config_sizes, but it's
-	 * unlikely we'll ever see anything but 128K.
+	 * Per UEFI 2.7, the minimum size of the Label Storage Area is large
+	 * enough to hold 2 index blocks and 2 labels.  The minimum index
+	 * block size is 256 bytes, and the minimum label size is 256 bytes.
 	 */
 	nslot = nvdimm_num_label_slots(ndd);
 	space = ndd->nsarea.config_size - nslot * sizeof_namespace_label(ndd);
-	size = ALIGN(sizeof(struct nd_namespace_index) + DIV_ROUND_UP(nslot, 8),
-			NSINDEX_ALIGN) * 2;
-	if (size <= space)
+	size = __sizeof_namespace_index(nslot) * 2;
+	if (size <= space && nslot >= 2)
 		return size / 2;
 
 	dev_err(ndd->dev, "label area (%d) too small to host (%d byte) labels\n",
@@ -121,8 +135,7 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd)
 
 		memcpy(sig, nsindex[i]->sig, NSINDEX_SIG_LEN);
 		if (memcmp(sig, NSINDEX_SIGNATURE, NSINDEX_SIG_LEN) != 0) {
-			dev_dbg(dev, "%s: nsindex%d signature invalid\n",
-					__func__, i);
+			dev_dbg(dev, "nsindex%d signature invalid\n", i);
 			continue;
 		}
 
@@ -135,8 +148,8 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd)
 			labelsize = 128;
 
 		if (labelsize != sizeof_namespace_label(ndd)) {
-			dev_dbg(dev, "%s: nsindex%d labelsize %d invalid\n",
-					__func__, i, nsindex[i]->labelsize);
+			dev_dbg(dev, "nsindex%d labelsize %d invalid\n",
+					i, nsindex[i]->labelsize);
 			continue;
 		}
 
@@ -145,30 +158,28 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd)
 		sum = nd_fletcher64(nsindex[i], sizeof_namespace_index(ndd), 1);
 		nsindex[i]->checksum = __cpu_to_le64(sum_save);
 		if (sum != sum_save) {
-			dev_dbg(dev, "%s: nsindex%d checksum invalid\n",
-					__func__, i);
+			dev_dbg(dev, "nsindex%d checksum invalid\n", i);
 			continue;
 		}
 
 		seq = __le32_to_cpu(nsindex[i]->seq);
 		if ((seq & NSINDEX_SEQ_MASK) == 0) {
-			dev_dbg(dev, "%s: nsindex%d sequence: %#x invalid\n",
-					__func__, i, seq);
+			dev_dbg(dev, "nsindex%d sequence: %#x invalid\n", i, seq);
 			continue;
 		}
 
 		/* sanity check the index against expected values */
 		if (__le64_to_cpu(nsindex[i]->myoff)
 				!= i * sizeof_namespace_index(ndd)) {
-			dev_dbg(dev, "%s: nsindex%d myoff: %#llx invalid\n",
-					__func__, i, (unsigned long long)
+			dev_dbg(dev, "nsindex%d myoff: %#llx invalid\n",
+					i, (unsigned long long)
 					__le64_to_cpu(nsindex[i]->myoff));
 			continue;
 		}
 		if (__le64_to_cpu(nsindex[i]->otheroff)
 				!= (!i) * sizeof_namespace_index(ndd)) {
-			dev_dbg(dev, "%s: nsindex%d otheroff: %#llx invalid\n",
-					__func__, i, (unsigned long long)
+			dev_dbg(dev, "nsindex%d otheroff: %#llx invalid\n",
+					i, (unsigned long long)
 					__le64_to_cpu(nsindex[i]->otheroff));
 			continue;
 		}
@@ -176,8 +187,7 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd)
 		size = __le64_to_cpu(nsindex[i]->mysize);
 		if (size > sizeof_namespace_index(ndd)
 				|| size < sizeof(struct nd_namespace_index)) {
-			dev_dbg(dev, "%s: nsindex%d mysize: %#llx invalid\n",
-					__func__, i, size);
+			dev_dbg(dev, "nsindex%d mysize: %#llx invalid\n", i, size);
 			continue;
 		}
 
@@ -185,9 +195,8 @@ static int __nd_label_validate(struct nvdimm_drvdata *ndd)
 		if (nslot * sizeof_namespace_label(ndd)
 				+ 2 * sizeof_namespace_index(ndd)
 				> ndd->nsarea.config_size) {
-			dev_dbg(dev, "%s: nsindex%d nslot: %u invalid, config_size: %#x\n",
-					__func__, i, nslot,
-					ndd->nsarea.config_size);
+			dev_dbg(dev, "nsindex%d nslot: %u invalid, config_size: %#x\n",
+					i, nslot, ndd->nsarea.config_size);
 			continue;
 		}
 		valid[i] = true;
@@ -356,8 +365,8 @@ static bool slot_valid(struct nvdimm_drvdata *ndd,
 		sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1);
 		nd_label->checksum = __cpu_to_le64(sum_save);
 		if (sum != sum_save) {
-			dev_dbg(ndd->dev, "%s fail checksum. slot: %d expect: %#llx\n",
-				__func__, slot, sum);
+			dev_dbg(ndd->dev, "fail checksum. slot: %d expect: %#llx\n",
+				slot, sum);
 			return false;
 		}
 	}
@@ -422,8 +431,8 @@ int nd_label_active_count(struct nvdimm_drvdata *ndd)
 			u64 dpa = __le64_to_cpu(nd_label->dpa);
 
 			dev_dbg(ndd->dev,
-				"%s: slot%d invalid slot: %d dpa: %llx size: %llx\n",
-					__func__, slot, label_slot, dpa, size);
+				"slot%d invalid slot: %d dpa: %llx size: %llx\n",
+					slot, label_slot, dpa, size);
 			continue;
 		}
 		count++;
@@ -650,7 +659,7 @@ static int __pmem_label_update(struct nd_region *nd_region,
 	slot = nd_label_alloc_slot(ndd);
 	if (slot == UINT_MAX)
 		return -ENXIO;
-	dev_dbg(ndd->dev, "%s: allocated: %d\n", __func__, slot);
+	dev_dbg(ndd->dev, "allocated: %d\n", slot);
 
 	nd_label = to_label(ndd, slot);
 	memset(nd_label, 0, sizeof_namespace_label(ndd));
@@ -678,7 +687,7 @@ static int __pmem_label_update(struct nd_region *nd_region,
 		sum = nd_fletcher64(nd_label, sizeof_namespace_label(ndd), 1);
 		nd_label->checksum = __cpu_to_le64(sum);
 	}
-	nd_dbg_dpa(nd_region, ndd, res, "%s\n", __func__);
+	nd_dbg_dpa(nd_region, ndd, res, "\n");
 
 	/* update label */
 	offset = nd_label_offset(ndd, nd_label);
@@ -700,7 +709,7 @@ static int __pmem_label_update(struct nd_region *nd_region,
 		break;
 	}
 	if (victim) {
-		dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot);
+		dev_dbg(ndd->dev, "free: %d\n", slot);
 		slot = to_slot(ndd, victim->label);
 		nd_label_free_slot(ndd, slot);
 		victim->label = NULL;
@@ -868,7 +877,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 		slot = nd_label_alloc_slot(ndd);
 		if (slot == UINT_MAX)
 			goto abort;
-		dev_dbg(ndd->dev, "%s: allocated: %d\n", __func__, slot);
+		dev_dbg(ndd->dev, "allocated: %d\n", slot);
 
 		nd_label = to_label(ndd, slot);
 		memset(nd_label, 0, sizeof_namespace_label(ndd));
@@ -928,7 +937,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 
 	/* free up now unused slots in the new index */
 	for_each_set_bit(slot, victim_map, victim_map ? nslot : 0) {
-		dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot);
+		dev_dbg(ndd->dev, "free: %d\n", slot);
 		nd_label_free_slot(ndd, slot);
 	}
 
@@ -1092,7 +1101,7 @@ static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
 		active--;
 		slot = to_slot(ndd, nd_label);
 		nd_label_free_slot(ndd, slot);
-		dev_dbg(ndd->dev, "%s: free: %d\n", __func__, slot);
+		dev_dbg(ndd->dev, "free: %d\n", slot);
 		list_move_tail(&label_ent->list, &list);
 		label_ent->label = NULL;
 	}
@@ -1100,7 +1109,7 @@ static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
 
 	if (active == 0) {
 		nd_mapping_free_labels(nd_mapping);
-		dev_dbg(ndd->dev, "%s: no more active labels\n", __func__);
+		dev_dbg(ndd->dev, "no more active labels\n");
 	}
 	mutex_unlock(&nd_mapping->lock);
 
diff --git a/drivers/nvdimm/label.h b/drivers/nvdimm/label.h
index 1ebf4d3d01ba..18bbe183b3a9 100644
--- a/drivers/nvdimm/label.h
+++ b/drivers/nvdimm/label.h
@@ -33,7 +33,7 @@ enum {
 	BTTINFO_UUID_LEN = 16,
 	BTTINFO_FLAG_ERROR = 0x1,    /* error state (read-only) */
 	BTTINFO_MAJOR_VERSION = 1,
-	ND_LABEL_MIN_SIZE = 512 * 129, /* see sizeof_namespace_index() */
+	ND_LABEL_MIN_SIZE = 256 * 4, /* see sizeof_namespace_index() */
 	ND_LABEL_ID_SIZE = 50,
 	ND_NSINDEX_INIT = 0x1,
 };
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 658ada497be0..28afdd668905 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -421,7 +421,7 @@ static ssize_t alt_name_store(struct device *dev,
 	rc = __alt_name_store(dev, buf, len);
 	if (rc >= 0)
 		rc = nd_namespace_label_update(nd_region, dev);
-	dev_dbg(dev, "%s: %s(%zd)\n", __func__, rc < 0 ? "fail " : "", rc);
+	dev_dbg(dev, "%s(%zd)\n", rc < 0 ? "fail " : "", rc);
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -1007,7 +1007,7 @@ static ssize_t __size_store(struct device *dev, unsigned long long val)
 	if (uuid_not_set(uuid, dev, __func__))
 		return -ENXIO;
 	if (nd_region->ndr_mappings == 0) {
-		dev_dbg(dev, "%s: not associated with dimm(s)\n", __func__);
+		dev_dbg(dev, "not associated with dimm(s)\n");
 		return -ENXIO;
 	}
 
@@ -1105,8 +1105,7 @@ static ssize_t size_store(struct device *dev,
 		*uuid = NULL;
 	}
 
-	dev_dbg(dev, "%s: %llx %s (%d)\n", __func__, val, rc < 0
-			? "fail" : "success", rc);
+	dev_dbg(dev, "%llx %s (%d)\n", val, rc < 0 ? "fail" : "success", rc);
 
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
@@ -1270,8 +1269,8 @@ static ssize_t uuid_store(struct device *dev,
 		rc = nd_namespace_label_update(nd_region, dev);
 	else
 		kfree(uuid);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -1355,9 +1354,8 @@ static ssize_t sector_size_store(struct device *dev,
 		rc = nd_size_select_store(dev, buf, lbasize, supported);
 	if (rc >= 0)
 		rc = nd_namespace_label_update(nd_region, dev);
-	dev_dbg(dev, "%s: result: %zd %s: %s%s", __func__,
-			rc, rc < 0 ? "tried" : "wrote", buf,
-			buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd %s: %s%s", rc, rc < 0 ? "tried" : "wrote",
+			buf, buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -1519,7 +1517,7 @@ static ssize_t holder_class_store(struct device *dev,
 	rc = __holder_class_store(dev, buf);
 	if (rc >= 0)
 		rc = nd_namespace_label_update(nd_region, dev);
-	dev_dbg(dev, "%s: %s(%zd)\n", __func__, rc < 0 ? "fail " : "", rc);
+	dev_dbg(dev, "%s(%zd)\n", rc < 0 ? "fail " : "", rc);
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -1717,8 +1715,7 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
 		if (uuid_not_set(nsblk->uuid, &ndns->dev, __func__))
 			return ERR_PTR(-ENODEV);
 		if (!nsblk->lbasize) {
-			dev_dbg(&ndns->dev, "%s: sector size not set\n",
-				__func__);
+			dev_dbg(&ndns->dev, "sector size not set\n");
 			return ERR_PTR(-ENODEV);
 		}
 		if (!nd_namespace_blk_validate(nsblk))
@@ -1798,9 +1795,7 @@ static bool has_uuid_at_pos(struct nd_region *nd_region, u8 *uuid,
 			}
 
 			if (found_uuid) {
-				dev_dbg(ndd->dev,
-						"%s duplicate entry for uuid\n",
-						__func__);
+				dev_dbg(ndd->dev, "duplicate entry for uuid\n");
 				return false;
 			}
 			found_uuid = true;
@@ -1926,7 +1921,7 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region,
 	}
 
 	if (i < nd_region->ndr_mappings) {
-		struct nvdimm_drvdata *ndd = to_ndd(&nd_region->mapping[i]);
+		struct nvdimm *nvdimm = nd_region->mapping[i].nvdimm;
 
 		/*
 		 * Give up if we don't find an instance of a uuid at each
@@ -1934,7 +1929,7 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region,
 		 * find a dimm with two instances of the same uuid.
 		 */
 		dev_err(&nd_region->dev, "%s missing label for %pUb\n",
-				dev_name(ndd->dev), nd_label->uuid);
+				nvdimm_name(nvdimm), nd_label->uuid);
 		rc = -EINVAL;
 		goto err;
 	}
@@ -1994,14 +1989,13 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region,
 	namespace_pmem_release(dev);
 	switch (rc) {
 	case -EINVAL:
-		dev_dbg(&nd_region->dev, "%s: invalid label(s)\n", __func__);
+		dev_dbg(&nd_region->dev, "invalid label(s)\n");
 		break;
 	case -ENODEV:
-		dev_dbg(&nd_region->dev, "%s: label not found\n", __func__);
+		dev_dbg(&nd_region->dev, "label not found\n");
 		break;
 	default:
-		dev_dbg(&nd_region->dev, "%s: unexpected err: %d\n",
-				__func__, rc);
+		dev_dbg(&nd_region->dev, "unexpected err: %d\n", rc);
 		break;
 	}
 	return ERR_PTR(rc);
@@ -2334,8 +2328,8 @@ static struct device **scan_labels(struct nd_region *nd_region)
 
 	}
 
-	dev_dbg(&nd_region->dev, "%s: discovered %d %s namespace%s\n",
-			__func__, count, is_nd_blk(&nd_region->dev)
+	dev_dbg(&nd_region->dev, "discovered %d %s namespace%s\n",
+			count, is_nd_blk(&nd_region->dev)
 			? "blk" : "pmem", count == 1 ? "" : "s");
 
 	if (count == 0) {
@@ -2467,7 +2461,7 @@ static int init_active_labels(struct nd_region *nd_region)
 		get_ndd(ndd);
 
 		count = nd_label_active_count(ndd);
-		dev_dbg(ndd->dev, "%s: %d\n", __func__, count);
+		dev_dbg(ndd->dev, "count: %d\n", count);
 		if (!count)
 			continue;
 		for (j = 0; j < count; j++) {
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 184e070d50a2..32e0364b48b9 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -340,7 +340,6 @@ static inline struct device *nd_dax_create(struct nd_region *nd_region)
 }
 #endif
 
-struct nd_region *to_nd_region(struct device *dev);
 int nd_region_to_nstype(struct nd_region *nd_region);
 int nd_region_register_namespaces(struct nd_region *nd_region, int *err);
 u64 nd_region_interleave_set_cookie(struct nd_region *nd_region,
diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
new file mode 100644
index 000000000000..85013bad35de
--- /dev/null
+++ b/drivers/nvdimm/of_pmem.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#define pr_fmt(fmt) "of_pmem: " fmt
+
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/libnvdimm.h>
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+
+static const struct attribute_group *region_attr_groups[] = {
+	&nd_region_attribute_group,
+	&nd_device_attribute_group,
+	NULL,
+};
+
+static const struct attribute_group *bus_attr_groups[] = {
+	&nvdimm_bus_attribute_group,
+	NULL,
+};
+
+struct of_pmem_private {
+	struct nvdimm_bus_descriptor bus_desc;
+	struct nvdimm_bus *bus;
+};
+
+static int of_pmem_region_probe(struct platform_device *pdev)
+{
+	struct of_pmem_private *priv;
+	struct device_node *np;
+	struct nvdimm_bus *bus;
+	bool is_volatile;
+	int i;
+
+	np = dev_of_node(&pdev->dev);
+	if (!np)
+		return -ENXIO;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->bus_desc.attr_groups = bus_attr_groups;
+	priv->bus_desc.provider_name = "of_pmem";
+	priv->bus_desc.module = THIS_MODULE;
+	priv->bus_desc.of_node = np;
+
+	priv->bus = bus = nvdimm_bus_register(&pdev->dev, &priv->bus_desc);
+	if (!bus) {
+		kfree(priv);
+		return -ENODEV;
+	}
+	platform_set_drvdata(pdev, priv);
+
+	is_volatile = !!of_find_property(np, "volatile", NULL);
+	dev_dbg(&pdev->dev, "Registering %s regions from %pOF\n",
+			is_volatile ? "volatile" : "non-volatile",  np);
+
+	for (i = 0; i < pdev->num_resources; i++) {
+		struct nd_region_desc ndr_desc;
+		struct nd_region *region;
+
+		/*
+		 * NB: libnvdimm copies the data from ndr_desc into it's own
+		 * structures so passing a stack pointer is fine.
+		 */
+		memset(&ndr_desc, 0, sizeof(ndr_desc));
+		ndr_desc.attr_groups = region_attr_groups;
+		ndr_desc.numa_node = of_node_to_nid(np);
+		ndr_desc.res = &pdev->resource[i];
+		ndr_desc.of_node = np;
+		set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+
+		if (is_volatile)
+			region = nvdimm_volatile_region_create(bus, &ndr_desc);
+		else
+			region = nvdimm_pmem_region_create(bus, &ndr_desc);
+
+		if (!region)
+			dev_warn(&pdev->dev, "Unable to register region %pR from %pOF\n",
+					ndr_desc.res, np);
+		else
+			dev_dbg(&pdev->dev, "Registered region %pR from %pOF\n",
+					ndr_desc.res, np);
+	}
+
+	return 0;
+}
+
+static int of_pmem_region_remove(struct platform_device *pdev)
+{
+	struct of_pmem_private *priv = platform_get_drvdata(pdev);
+
+	nvdimm_bus_unregister(priv->bus);
+	kfree(priv);
+
+	return 0;
+}
+
+static const struct of_device_id of_pmem_region_match[] = {
+	{ .compatible = "pmem-region" },
+	{ },
+};
+
+static struct platform_driver of_pmem_region_driver = {
+	.probe = of_pmem_region_probe,
+	.remove = of_pmem_region_remove,
+	.driver = {
+		.name = "of_pmem",
+		.owner = THIS_MODULE,
+		.of_match_table = of_pmem_region_match,
+	},
+};
+
+module_platform_driver(of_pmem_region_driver);
+MODULE_DEVICE_TABLE(of, of_pmem_region_match);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("IBM Corporation");
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 2f4d18752c97..30b08791597d 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -27,7 +27,7 @@ static void nd_pfn_release(struct device *dev)
 	struct nd_region *nd_region = to_nd_region(dev->parent);
 	struct nd_pfn *nd_pfn = to_nd_pfn(dev);
 
-	dev_dbg(dev, "%s\n", __func__);
+	dev_dbg(dev, "trace\n");
 	nd_detach_ndns(&nd_pfn->dev, &nd_pfn->ndns);
 	ida_simple_remove(&nd_region->pfn_ida, nd_pfn->id);
 	kfree(nd_pfn->uuid);
@@ -94,8 +94,8 @@ static ssize_t mode_store(struct device *dev,
 		else
 			rc = -EINVAL;
 	}
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -144,8 +144,8 @@ static ssize_t align_store(struct device *dev,
 	nvdimm_bus_lock(dev);
 	rc = nd_size_select_store(dev, buf, &nd_pfn->align,
 			nd_pfn_supported_alignments());
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -171,8 +171,8 @@ static ssize_t uuid_store(struct device *dev,
 
 	device_lock(dev);
 	rc = nd_uuid_store(dev, &nd_pfn->uuid, buf, len);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	device_unlock(dev);
 
 	return rc ? rc : len;
@@ -201,8 +201,8 @@ static ssize_t namespace_store(struct device *dev,
 	device_lock(dev);
 	nvdimm_bus_lock(dev);
 	rc = nd_namespace_store(dev, &nd_pfn->ndns, buf, len);
-	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
-			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
+	dev_dbg(dev, "result: %zd wrote: %s%s", rc, buf,
+			buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
 	device_unlock(dev);
 
@@ -314,8 +314,8 @@ struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 	dev = &nd_pfn->dev;
 	device_initialize(&nd_pfn->dev);
 	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
-		dev_dbg(&ndns->dev, "%s failed, already claimed by %s\n",
-				__func__, dev_name(ndns->claim));
+		dev_dbg(&ndns->dev, "failed, already claimed by %s\n",
+				dev_name(ndns->claim));
 		put_device(dev);
 		return NULL;
 	}
@@ -510,8 +510,7 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 	nd_pfn = to_nd_pfn(pfn_dev);
 	nd_pfn->pfn_sb = pfn_sb;
 	rc = nd_pfn_validate(nd_pfn, PFN_SIG);
-	dev_dbg(dev, "%s: pfn: %s\n", __func__,
-			rc == 0 ? dev_name(pfn_dev) : "<none>");
+	dev_dbg(dev, "pfn: %s\n", rc == 0 ? dev_name(pfn_dev) : "<none>");
 	if (rc < 0) {
 		nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
 		put_device(pfn_dev);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 5a96d30c294a..9d714926ecf5 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -66,7 +66,7 @@ static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
 		rc = BLK_STS_IOERR;
 	if (cleared > 0 && cleared / 512) {
 		cleared /= 512;
-		dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
+		dev_dbg(dev, "%#llx clear %ld sector%s\n",
 				(unsigned long long) sector, cleared,
 				cleared > 1 ? "s" : "");
 		badblocks_clear(&pmem->bb, sector, cleared);
@@ -547,17 +547,7 @@ static struct nd_device_driver nd_pmem_driver = {
 	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
 };
 
-static int __init pmem_init(void)
-{
-	return nd_driver_register(&nd_pmem_driver);
-}
-module_init(pmem_init);
-
-static void pmem_exit(void)
-{
-	driver_unregister(&nd_pmem_driver.drv);
-}
-module_exit(pmem_exit);
+module_nd_driver(nd_pmem_driver);
 
 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
index 034f0a07d627..b9ca0033cc99 100644
--- a/drivers/nvdimm/region.c
+++ b/drivers/nvdimm/region.c
@@ -27,10 +27,10 @@ static int nd_region_probe(struct device *dev)
 	if (nd_region->num_lanes > num_online_cpus()
 			&& nd_region->num_lanes < num_possible_cpus()
 			&& !test_and_set_bit(0, &once)) {
-		dev_info(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
+		dev_dbg(dev, "online cpus (%d) < concurrent i/o lanes (%d) < possible cpus (%d)\n",
 				num_online_cpus(), nd_region->num_lanes,
 				num_possible_cpus());
-		dev_info(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
+		dev_dbg(dev, "setting nr_cpus=%d may yield better libnvdimm device performance\n",
 				nd_region->num_lanes);
 	}
 
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 1593e1806b16..a612be6f019d 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -182,6 +182,14 @@ struct nd_region *to_nd_region(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(to_nd_region);
 
+struct device *nd_region_dev(struct nd_region *nd_region)
+{
+	if (!nd_region)
+		return NULL;
+	return &nd_region->dev;
+}
+EXPORT_SYMBOL_GPL(nd_region_dev);
+
 struct nd_blk_region *to_nd_blk_region(struct device *dev)
 {
 	struct nd_region *nd_region = to_nd_region(dev);
@@ -1014,6 +1022,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 	dev->parent = &nvdimm_bus->dev;
 	dev->type = dev_type;
 	dev->groups = ndr_desc->attr_groups;
+	dev->of_node = ndr_desc->of_node;
 	nd_region->ndr_size = resource_size(ndr_desc->res);
 	nd_region->ndr_start = ndr_desc->res->start;
 	nd_device_register(dev);
diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig
index 1444333210c7..9ac7574e3cfb 100644
--- a/drivers/s390/block/Kconfig
+++ b/drivers/s390/block/Kconfig
@@ -15,8 +15,8 @@ config BLK_DEV_XPRAM
 
 config DCSSBLK
 	def_tristate m
-	select DAX
 	select FS_DAX_LIMITED
+	select DAX_DRIVER
 	prompt "DCSSBLK support"
 	depends on S390 && BLOCK
 	help
author	Linus Torvalds <torvalds@linux-foundation.org>	2018-04-10 10:25:57 -0700
committer	Linus Torvalds <torvalds@linux-foundation.org>	2018-04-10 10:25:57 -0700
commit	9f3a0941fb5efaa4d27911e251dc595034d58baa (patch)
tree	7212d9872b41b73a0b3c4f8c991039b639add212 /drivers
parent	fbe173e3ffbd897b5a859020d714c0eaf4af2a1a (diff)
parent	e13e75b86ef2f88e3a47d672dd4c52a293efb95b (diff)