Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 789 insertions, 0 deletions

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
new file mode 100644
index 000000000..96e6e9a5f
--- /dev/null
+++ b/drivers/nvdimm/pmem.c
@@ -0,0 +1,789 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Persistent Memory Driver
+ *
+ * Copyright (c) 2014-2015, Intel Corporation.
+ * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
+ * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
+ */
+
+#include <linux/blkdev.h>
+#include <linux/pagemap.h>
+#include <linux/hdreg.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/set_memory.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/badblocks.h>
+#include <linux/memremap.h>
+#include <linux/vmalloc.h>
+#include <linux/blk-mq.h>
+#include <linux/pfn_t.h>
+#include <linux/slab.h>
+#include <linux/uio.h>
+#include <linux/dax.h>
+#include <linux/nd.h>
+#include <linux/mm.h>
+#include <asm/cacheflush.h>
+#include "pmem.h"
+#include "btt.h"
+#include "pfn.h"
+#include "nd.h"
+
+static struct device *to_dev(struct pmem_device *pmem)
+{
+	/*
+	 * nvdimm bus services need a 'dev' parameter, and we record the device
+	 * at init in bb.dev.
+	 */
+	return pmem->bb.dev;
+}
+
+static struct nd_region *to_region(struct pmem_device *pmem)
+{
+	return to_nd_region(to_dev(pmem)->parent);
+}
+
+static phys_addr_t pmem_to_phys(struct pmem_device *pmem, phys_addr_t offset)
+{
+	return pmem->phys_addr + offset;
+}
+
+static sector_t to_sect(struct pmem_device *pmem, phys_addr_t offset)
+{
+	return (offset - pmem->data_offset) >> SECTOR_SHIFT;
+}
+
+static phys_addr_t to_offset(struct pmem_device *pmem, sector_t sector)
+{
+	return (sector << SECTOR_SHIFT) + pmem->data_offset;
+}
+
+static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset,
+		unsigned int len)
+{
+	phys_addr_t phys = pmem_to_phys(pmem, offset);
+	unsigned long pfn_start, pfn_end, pfn;
+
+	/* only pmem in the linear map supports HWPoison */
+	if (is_vmalloc_addr(pmem->virt_addr))
+		return;
+
+	pfn_start = PHYS_PFN(phys);
+	pfn_end = pfn_start + PHYS_PFN(len);
+	for (pfn = pfn_start; pfn < pfn_end; pfn++) {
+		struct page *page = pfn_to_page(pfn);
+
+		/*
+		 * Note, no need to hold a get_dev_pagemap() reference
+		 * here since we're in the driver I/O path and
+		 * outstanding I/O requests pin the dev_pagemap.
+		 */
+		if (test_and_clear_pmem_poison(page))
+			clear_mce_nospec(pfn);
+	}
+}
+
+static void pmem_clear_bb(struct pmem_device *pmem, sector_t sector, long blks)
+{
+	if (blks == 0)
+		return;
+	badblocks_clear(&pmem->bb, sector, blks);
+	if (pmem->bb_state)
+		sysfs_notify_dirent(pmem->bb_state);
+}
+
+static long __pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len)
+{
+	phys_addr_t phys = pmem_to_phys(pmem, offset);
+	long cleared = nvdimm_clear_poison(to_dev(pmem), phys, len);
+
+	if (cleared > 0) {
+		pmem_mkpage_present(pmem, offset, cleared);
+		arch_invalidate_pmem(pmem->virt_addr + offset, len);
+	}
+	return cleared;
+}
+
+static blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len)
+{
+	long cleared = __pmem_clear_poison(pmem, offset, len);
+
+	if (cleared < 0)
+		return BLK_STS_IOERR;
+
+	pmem_clear_bb(pmem, to_sect(pmem, offset), cleared >> SECTOR_SHIFT);
+	if (cleared < len)
+		return BLK_STS_IOERR;
+	return BLK_STS_OK;
+}
+
+static void write_pmem(void *pmem_addr, struct page *page,
+		unsigned int off, unsigned int len)
+{
+	unsigned int chunk;
+	void *mem;
+
+	while (len) {
+		mem = kmap_atomic(page);
+		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
+		memcpy_flushcache(pmem_addr, mem + off, chunk);
+		kunmap_atomic(mem);
+		len -= chunk;
+		off = 0;
+		page++;
+		pmem_addr += chunk;
+	}
+}
+
+static blk_status_t read_pmem(struct page *page, unsigned int off,
+		void *pmem_addr, unsigned int len)
+{
+	unsigned int chunk;
+	unsigned long rem;
+	void *mem;
+
+	while (len) {
+		mem = kmap_atomic(page);
+		chunk = min_t(unsigned int, len, PAGE_SIZE - off);
+		rem = copy_mc_to_kernel(mem + off, pmem_addr, chunk);
+		kunmap_atomic(mem);
+		if (rem)
+			return BLK_STS_IOERR;
+		len -= chunk;
+		off = 0;
+		page++;
+		pmem_addr += chunk;
+	}
+	return BLK_STS_OK;
+}
+
+static blk_status_t pmem_do_read(struct pmem_device *pmem,
+			struct page *page, unsigned int page_off,
+			sector_t sector, unsigned int len)
+{
+	blk_status_t rc;
+	phys_addr_t pmem_off = to_offset(pmem, sector);
+	void *pmem_addr = pmem->virt_addr + pmem_off;
+
+	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
+		return BLK_STS_IOERR;
+
+	rc = read_pmem(page, page_off, pmem_addr, len);
+	flush_dcache_page(page);
+	return rc;
+}
+
+static blk_status_t pmem_do_write(struct pmem_device *pmem,
+			struct page *page, unsigned int page_off,
+			sector_t sector, unsigned int len)
+{
+	phys_addr_t pmem_off = to_offset(pmem, sector);
+	void *pmem_addr = pmem->virt_addr + pmem_off;
+
+	if (unlikely(is_bad_pmem(&pmem->bb, sector, len))) {
+		blk_status_t rc = pmem_clear_poison(pmem, pmem_off, len);
+
+		if (rc != BLK_STS_OK)
+			return rc;
+	}
+
+	flush_dcache_page(page);
+	write_pmem(pmem_addr, page, page_off, len);
+
+	return BLK_STS_OK;
+}
+
+static void pmem_submit_bio(struct bio *bio)
+{
+	int ret = 0;
+	blk_status_t rc = 0;
+	bool do_acct;
+	unsigned long start;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	struct pmem_device *pmem = bio->bi_bdev->bd_disk->private_data;
+	struct nd_region *nd_region = to_region(pmem);
+
+	if (bio->bi_opf & REQ_PREFLUSH)
+		ret = nvdimm_flush(nd_region, bio);
+
+	do_acct = blk_queue_io_stat(bio->bi_bdev->bd_disk->queue);
+	if (do_acct)
+		start = bio_start_io_acct(bio);
+	bio_for_each_segment(bvec, bio, iter) {
+		if (op_is_write(bio_op(bio)))
+			rc = pmem_do_write(pmem, bvec.bv_page, bvec.bv_offset,
+				iter.bi_sector, bvec.bv_len);
+		else
+			rc = pmem_do_read(pmem, bvec.bv_page, bvec.bv_offset,
+				iter.bi_sector, bvec.bv_len);
+		if (rc) {
+			bio->bi_status = rc;
+			break;
+		}
+	}
+	if (do_acct)
+		bio_end_io_acct(bio, start);
+
+	if (bio->bi_opf & REQ_FUA)
+		ret = nvdimm_flush(nd_region, bio);
+
+	if (ret)
+		bio->bi_status = errno_to_blk_status(ret);
+
+	bio_endio(bio);
+}
+
+static int pmem_rw_page(struct block_device *bdev, sector_t sector,
+		       struct page *page, enum req_op op)
+{
+	struct pmem_device *pmem = bdev->bd_disk->private_data;
+	blk_status_t rc;
+
+	if (op_is_write(op))
+		rc = pmem_do_write(pmem, page, 0, sector, thp_size(page));
+	else
+		rc = pmem_do_read(pmem, page, 0, sector, thp_size(page));
+	/*
+	 * The ->rw_page interface is subtle and tricky.  The core
+	 * retries on any error, so we can only invoke page_endio() in
+	 * the successful completion case.  Otherwise, we'll see crashes
+	 * caused by double completion.
+	 */
+	if (rc == 0)
+		page_endio(page, op_is_write(op), 0);
+
+	return blk_status_to_errno(rc);
+}
+
+/* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
+__weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
+		long nr_pages, enum dax_access_mode mode, void **kaddr,
+		pfn_t *pfn)
+{
+	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
+	sector_t sector = PFN_PHYS(pgoff) >> SECTOR_SHIFT;
+	unsigned int num = PFN_PHYS(nr_pages) >> SECTOR_SHIFT;
+	struct badblocks *bb = &pmem->bb;
+	sector_t first_bad;
+	int num_bad;
+
+	if (kaddr)
+		*kaddr = pmem->virt_addr + offset;
+	if (pfn)
+		*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
+
+	if (bb->count &&
+	    badblocks_check(bb, sector, num, &first_bad, &num_bad)) {
+		long actual_nr;
+
+		if (mode != DAX_RECOVERY_WRITE)
+			return -EIO;
+
+		/*
+		 * Set the recovery stride is set to kernel page size because
+		 * the underlying driver and firmware clear poison functions
+		 * don't appear to handle large chunk(such as 2MiB) reliably.
+		 */
+		actual_nr = PHYS_PFN(
+			PAGE_ALIGN((first_bad - sector) << SECTOR_SHIFT));
+		dev_dbg(pmem->bb.dev, "start sector(%llu), nr_pages(%ld), first_bad(%llu), actual_nr(%ld)\n",
+				sector, nr_pages, first_bad, actual_nr);
+		if (actual_nr)
+			return actual_nr;
+		return 1;
+	}
+
+	/*
+	 * If badblocks are present but not in the range, limit known good range
+	 * to the requested range.
+	 */
+	if (bb->count)
+		return nr_pages;
+	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
+}
+
+static const struct block_device_operations pmem_fops = {
+	.owner =		THIS_MODULE,
+	.submit_bio =		pmem_submit_bio,
+	.rw_page =		pmem_rw_page,
+};
+
+static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
+				    size_t nr_pages)
+{
+	struct pmem_device *pmem = dax_get_private(dax_dev);
+
+	return blk_status_to_errno(pmem_do_write(pmem, ZERO_PAGE(0), 0,
+				   PFN_PHYS(pgoff) >> SECTOR_SHIFT,
+				   PAGE_SIZE));
+}
+
+static long pmem_dax_direct_access(struct dax_device *dax_dev,
+		pgoff_t pgoff, long nr_pages, enum dax_access_mode mode,
+		void **kaddr, pfn_t *pfn)
+{
+	struct pmem_device *pmem = dax_get_private(dax_dev);
+
+	return __pmem_direct_access(pmem, pgoff, nr_pages, mode, kaddr, pfn);
+}
+
+/*
+ * The recovery write thread started out as a normal pwrite thread and
+ * when the filesystem was told about potential media error in the
+ * range, filesystem turns the normal pwrite to a dax_recovery_write.
+ *
+ * The recovery write consists of clearing media poison, clearing page
+ * HWPoison bit, reenable page-wide read-write permission, flush the
+ * caches and finally write.  A competing pread thread will be held
+ * off during the recovery process since data read back might not be
+ * valid, and this is achieved by clearing the badblock records after
+ * the recovery write is complete. Competing recovery write threads
+ * are already serialized by writer lock held by dax_iomap_rw().
+ */
+static size_t pmem_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	struct pmem_device *pmem = dax_get_private(dax_dev);
+	size_t olen, len, off;
+	phys_addr_t pmem_off;
+	struct device *dev = pmem->bb.dev;
+	long cleared;
+
+	off = offset_in_page(addr);
+	len = PFN_PHYS(PFN_UP(off + bytes));
+	if (!is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) >> SECTOR_SHIFT, len))
+		return _copy_from_iter_flushcache(addr, bytes, i);
+
+	/*
+	 * Not page-aligned range cannot be recovered. This should not
+	 * happen unless something else went wrong.
+	 */
+	if (off || !PAGE_ALIGNED(bytes)) {
+		dev_dbg(dev, "Found poison, but addr(%p) or bytes(%#zx) not page aligned\n",
+			addr, bytes);
+		return 0;
+	}
+
+	pmem_off = PFN_PHYS(pgoff) + pmem->data_offset;
+	cleared = __pmem_clear_poison(pmem, pmem_off, len);
+	if (cleared > 0 && cleared < len) {
+		dev_dbg(dev, "poison cleared only %ld out of %zu bytes\n",
+			cleared, len);
+		return 0;
+	}
+	if (cleared < 0) {
+		dev_dbg(dev, "poison clear failed: %ld\n", cleared);
+		return 0;
+	}
+
+	olen = _copy_from_iter_flushcache(addr, bytes, i);
+	pmem_clear_bb(pmem, to_sect(pmem, pmem_off), cleared >> SECTOR_SHIFT);
+
+	return olen;
+}
+
+static const struct dax_operations pmem_dax_ops = {
+	.direct_access = pmem_dax_direct_access,
+	.zero_page_range = pmem_dax_zero_page_range,
+	.recovery_write = pmem_recovery_write,
+};
+
+static ssize_t write_cache_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct pmem_device *pmem = dev_to_disk(dev)->private_data;
+
+	return sprintf(buf, "%d\n", !!dax_write_cache_enabled(pmem->dax_dev));
+}
+
+static ssize_t write_cache_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct pmem_device *pmem = dev_to_disk(dev)->private_data;
+	bool write_cache;
+	int rc;
+
+	rc = strtobool(buf, &write_cache);
+	if (rc)
+		return rc;
+	dax_write_cache(pmem->dax_dev, write_cache);
+	return len;
+}
+static DEVICE_ATTR_RW(write_cache);
+
+static umode_t dax_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+#ifndef CONFIG_ARCH_HAS_PMEM_API
+	if (a == &dev_attr_write_cache.attr)
+		return 0;
+#endif
+	return a->mode;
+}
+
+static struct attribute *dax_attributes[] = {
+	&dev_attr_write_cache.attr,
+	NULL,
+};
+
+static const struct attribute_group dax_attribute_group = {
+	.name		= "dax",
+	.attrs		= dax_attributes,
+	.is_visible	= dax_visible,
+};
+
+static const struct attribute_group *pmem_attribute_groups[] = {
+	&dax_attribute_group,
+	NULL,
+};
+
+static void pmem_release_disk(void *__pmem)
+{
+	struct pmem_device *pmem = __pmem;
+
+	dax_remove_host(pmem->disk);
+	kill_dax(pmem->dax_dev);
+	put_dax(pmem->dax_dev);
+	del_gendisk(pmem->disk);
+
+	put_disk(pmem->disk);
+}
+
+static int pmem_pagemap_memory_failure(struct dev_pagemap *pgmap,
+		unsigned long pfn, unsigned long nr_pages, int mf_flags)
+{
+	struct pmem_device *pmem =
+			container_of(pgmap, struct pmem_device, pgmap);
+	u64 offset = PFN_PHYS(pfn) - pmem->phys_addr - pmem->data_offset;
+	u64 len = nr_pages << PAGE_SHIFT;
+
+	return dax_holder_notify_failure(pmem->dax_dev, offset, len, mf_flags);
+}
+
+static const struct dev_pagemap_ops fsdax_pagemap_ops = {
+	.memory_failure		= pmem_pagemap_memory_failure,
+};
+
+static int pmem_attach_disk(struct device *dev,
+		struct nd_namespace_common *ndns)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	int nid = dev_to_node(dev), fua;
+	struct resource *res = &nsio->res;
+	struct range bb_range;
+	struct nd_pfn *nd_pfn = NULL;
+	struct dax_device *dax_dev;
+	struct nd_pfn_sb *pfn_sb;
+	struct pmem_device *pmem;
+	struct request_queue *q;
+	struct gendisk *disk;
+	void *addr;
+	int rc;
+
+	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
+	if (!pmem)
+		return -ENOMEM;
+
+	rc = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
+	if (rc)
+		return rc;
+
+	/* while nsio_rw_bytes is active, parse a pfn info block if present */
+	if (is_nd_pfn(dev)) {
+		nd_pfn = to_nd_pfn(dev);
+		rc = nvdimm_setup_pfn(nd_pfn, &pmem->pgmap);
+		if (rc)
+			return rc;
+	}
+
+	/* we're attaching a block device, disable raw namespace access */
+	devm_namespace_disable(dev, ndns);
+
+	dev_set_drvdata(dev, pmem);
+	pmem->phys_addr = res->start;
+	pmem->size = resource_size(res);
+	fua = nvdimm_has_flush(nd_region);
+	if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) || fua < 0) {
+		dev_warn(dev, "unable to guarantee persistence of writes\n");
+		fua = 0;
+	}
+
+	if (!devm_request_mem_region(dev, res->start, resource_size(res),
+				dev_name(&ndns->dev))) {
+		dev_warn(dev, "could not reserve region %pR\n", res);
+		return -EBUSY;
+	}
+
+	disk = blk_alloc_disk(nid);
+	if (!disk)
+		return -ENOMEM;
+	q = disk->queue;
+
+	pmem->disk = disk;
+	pmem->pgmap.owner = pmem;
+	pmem->pfn_flags = PFN_DEV;
+	if (is_nd_pfn(dev)) {
+		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
+		pmem->pgmap.ops = &fsdax_pagemap_ops;
+		addr = devm_memremap_pages(dev, &pmem->pgmap);
+		pfn_sb = nd_pfn->pfn_sb;
+		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
+		pmem->pfn_pad = resource_size(res) -
+			range_len(&pmem->pgmap.range);
+		pmem->pfn_flags |= PFN_MAP;
+		bb_range = pmem->pgmap.range;
+		bb_range.start += pmem->data_offset;
+	} else if (pmem_should_map_pages(dev)) {
+		pmem->pgmap.range.start = res->start;
+		pmem->pgmap.range.end = res->end;
+		pmem->pgmap.nr_range = 1;
+		pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
+		pmem->pgmap.ops = &fsdax_pagemap_ops;
+		addr = devm_memremap_pages(dev, &pmem->pgmap);
+		pmem->pfn_flags |= PFN_MAP;
+		bb_range = pmem->pgmap.range;
+	} else {
+		addr = devm_memremap(dev, pmem->phys_addr,
+				pmem->size, ARCH_MEMREMAP_PMEM);
+		bb_range.start =  res->start;
+		bb_range.end = res->end;
+	}
+
+	if (IS_ERR(addr)) {
+		rc = PTR_ERR(addr);
+		goto out;
+	}
+	pmem->virt_addr = addr;
+
+	blk_queue_write_cache(q, true, fua);
+	blk_queue_physical_block_size(q, PAGE_SIZE);
+	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
+	blk_queue_max_hw_sectors(q, UINT_MAX);
+	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
+	if (pmem->pfn_flags & PFN_MAP)
+		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
+
+	disk->fops		= &pmem_fops;
+	disk->private_data	= pmem;
+	nvdimm_namespace_disk_name(ndns, disk->disk_name);
+	set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
+			/ 512);
+	if (devm_init_badblocks(dev, &pmem->bb))
+		return -ENOMEM;
+	nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_range);
+	disk->bb = &pmem->bb;
+
+	dax_dev = alloc_dax(pmem, &pmem_dax_ops);
+	if (IS_ERR(dax_dev)) {
+		rc = PTR_ERR(dax_dev);
+		goto out;
+	}
+	set_dax_nocache(dax_dev);
+	set_dax_nomc(dax_dev);
+	if (is_nvdimm_sync(nd_region))
+		set_dax_synchronous(dax_dev);
+	rc = dax_add_host(dax_dev, disk);
+	if (rc)
+		goto out_cleanup_dax;
+	dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
+	pmem->dax_dev = dax_dev;
+
+	rc = device_add_disk(dev, disk, pmem_attribute_groups);
+	if (rc)
+		goto out_remove_host;
+	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
+		return -ENOMEM;
+
+	nvdimm_check_and_set_ro(disk);
+
+	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
+					  "badblocks");
+	if (!pmem->bb_state)
+		dev_warn(dev, "'badblocks' notification disabled\n");
+	return 0;
+
+out_remove_host:
+	dax_remove_host(pmem->disk);
+out_cleanup_dax:
+	kill_dax(pmem->dax_dev);
+	put_dax(pmem->dax_dev);
+out:
+	put_disk(pmem->disk);
+	return rc;
+}
+
+static int nd_pmem_probe(struct device *dev)
+{
+	int ret;
+	struct nd_namespace_common *ndns;
+
+	ndns = nvdimm_namespace_common_probe(dev);
+	if (IS_ERR(ndns))
+		return PTR_ERR(ndns);
+
+	if (is_nd_btt(dev))
+		return nvdimm_namespace_attach_btt(ndns);
+
+	if (is_nd_pfn(dev))
+		return pmem_attach_disk(dev, ndns);
+
+	ret = devm_namespace_enable(dev, ndns, nd_info_block_reserve());
+	if (ret)
+		return ret;
+
+	ret = nd_btt_probe(dev, ndns);
+	if (ret == 0)
+		return -ENXIO;
+
+	/*
+	 * We have two failure conditions here, there is no
+	 * info reserver block or we found a valid info reserve block
+	 * but failed to initialize the pfn superblock.
+	 *
+	 * For the first case consider namespace as a raw pmem namespace
+	 * and attach a disk.
+	 *
+	 * For the latter, consider this a success and advance the namespace
+	 * seed.
+	 */
+	ret = nd_pfn_probe(dev, ndns);
+	if (ret == 0)
+		return -ENXIO;
+	else if (ret == -EOPNOTSUPP)
+		return ret;
+
+	ret = nd_dax_probe(dev, ndns);
+	if (ret == 0)
+		return -ENXIO;
+	else if (ret == -EOPNOTSUPP)
+		return ret;
+
+	/* probe complete, attach handles namespace enabling */
+	devm_namespace_disable(dev, ndns);
+
+	return pmem_attach_disk(dev, ndns);
+}
+
+static void nd_pmem_remove(struct device *dev)
+{
+	struct pmem_device *pmem = dev_get_drvdata(dev);
+
+	if (is_nd_btt(dev))
+		nvdimm_namespace_detach_btt(to_nd_btt(dev));
+	else {
+		/*
+		 * Note, this assumes device_lock() context to not
+		 * race nd_pmem_notify()
+		 */
+		sysfs_put(pmem->bb_state);
+		pmem->bb_state = NULL;
+	}
+	nvdimm_flush(to_nd_region(dev->parent), NULL);
+}
+
+static void nd_pmem_shutdown(struct device *dev)
+{
+	nvdimm_flush(to_nd_region(dev->parent), NULL);
+}
+
+static void pmem_revalidate_poison(struct device *dev)
+{
+	struct nd_region *nd_region;
+	resource_size_t offset = 0, end_trunc = 0;
+	struct nd_namespace_common *ndns;
+	struct nd_namespace_io *nsio;
+	struct badblocks *bb;
+	struct range range;
+	struct kernfs_node *bb_state;
+
+	if (is_nd_btt(dev)) {
+		struct nd_btt *nd_btt = to_nd_btt(dev);
+
+		ndns = nd_btt->ndns;
+		nd_region = to_nd_region(ndns->dev.parent);
+		nsio = to_nd_namespace_io(&ndns->dev);
+		bb = &nsio->bb;
+		bb_state = NULL;
+	} else {
+		struct pmem_device *pmem = dev_get_drvdata(dev);
+
+		nd_region = to_region(pmem);
+		bb = &pmem->bb;
+		bb_state = pmem->bb_state;
+
+		if (is_nd_pfn(dev)) {
+			struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+			struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+
+			ndns = nd_pfn->ndns;
+			offset = pmem->data_offset +
+					__le32_to_cpu(pfn_sb->start_pad);
+			end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+		} else {
+			ndns = to_ndns(dev);
+		}
+
+		nsio = to_nd_namespace_io(&ndns->dev);
+	}
+
+	range.start = nsio->res.start + offset;
+	range.end = nsio->res.end - end_trunc;
+	nvdimm_badblocks_populate(nd_region, bb, &range);
+	if (bb_state)
+		sysfs_notify_dirent(bb_state);
+}
+
+static void pmem_revalidate_region(struct device *dev)
+{
+	struct pmem_device *pmem;
+
+	if (is_nd_btt(dev)) {
+		struct nd_btt *nd_btt = to_nd_btt(dev);
+		struct btt *btt = nd_btt->btt;
+
+		nvdimm_check_and_set_ro(btt->btt_disk);
+		return;
+	}
+
+	pmem = dev_get_drvdata(dev);
+	nvdimm_check_and_set_ro(pmem->disk);
+}
+
+static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
+{
+	switch (event) {
+	case NVDIMM_REVALIDATE_POISON:
+		pmem_revalidate_poison(dev);
+		break;
+	case NVDIMM_REVALIDATE_REGION:
+		pmem_revalidate_region(dev);
+		break;
+	default:
+		dev_WARN_ONCE(dev, 1, "notify: unknown event: %d\n", event);
+		break;
+	}
+}
+
+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,
+	.shutdown = nd_pmem_shutdown,
+	.drv = {
+		.name = "nd_pmem",
+	},
+	.type = ND_DRIVER_NAMESPACE_IO | ND_DRIVER_NAMESPACE_PMEM,
+};
+
+module_nd_driver(nd_pmem_driver);
+
+MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
+MODULE_LICENSE("GPL v2");