diff mbox

[v7,8/9] libnvdimm: move common function for pmem to pmem_core

Message ID 150412657792.69288.4657868119430253664.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Jiang Aug. 30, 2017, 8:56 p.m. UTC
In preparation for adding another pmem driver, moving all common functions
in pmem that will be used by new driver to a pmem_core module to share.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/nvdimm/Kconfig     |   10 +
 drivers/nvdimm/Makefile    |    3 
 drivers/nvdimm/pmem.c      |  401 +--------------------------------------
 drivers/nvdimm/pmem.h      |   54 +++++
 drivers/nvdimm/pmem_core.c |  451 ++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 528 insertions(+), 391 deletions(-)
 create mode 100644 drivers/nvdimm/pmem_core.c
diff mbox

Patch

diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 5bdd499..01fe9e8 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -17,12 +17,16 @@  menuconfig LIBNVDIMM
 
 if LIBNVDIMM
 
-config BLK_DEV_PMEM
-	tristate "PMEM: Persistent memory block device support"
-	default LIBNVDIMM
+config BLK_DEV_PMEM_CORE
+	tristate
 	select DAX
 	select ND_BTT if BTT
 	select ND_PFN if NVDIMM_PFN
+
+config BLK_DEV_PMEM
+	tristate "PMEM: Persistent memory block device support"
+	default LIBNVDIMM
+	select BLK_DEV_PMEM_CORE
 	help
 	  Memory ranges for PMEM are described by either an NFIT
 	  (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 909554c..0ce99cf 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -1,9 +1,12 @@ 
 obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o
+obj-$(CONFIG_BLK_DEV_PMEM_CORE) += nd_pmem_core.o
 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
 
+nd_pmem_core-y := pmem_core.o
+
 nd_pmem-y := pmem.o
 
 nd_btt-y := btt.o
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index b1460d1..025d22d 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -15,134 +15,9 @@ 
  * more details.
  */
 
-#include <asm/cacheflush.h>
-#include <linux/blkdev.h>
-#include <linux/hdreg.h>
 #include <linux/init.h>
-#include <linux/platform_device.h>
 #include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/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 "pmem.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 blk_status_t pmem_clear_poison(struct pmem_device *pmem,
-		phys_addr_t offset, unsigned int len)
-{
-	struct device *dev = to_dev(pmem);
-	sector_t sector;
-	long cleared;
-	blk_status_t rc = BLK_STS_OK;
-
-	sector = (offset - pmem->data_offset) / 512;
-
-	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
-	if (cleared < len)
-		rc = BLK_STS_IOERR;
-	if (cleared > 0 && cleared / 512) {
-		cleared /= 512;
-		dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
-				(unsigned long long) sector, cleared,
-				cleared > 1 ? "s" : "");
-		badblocks_clear(&pmem->bb, sector, cleared);
-		if (pmem->bb_state)
-			sysfs_notify_dirent(pmem->bb_state);
-	}
-
-	arch_invalidate_pmem(pmem->virt_addr + offset, len);
-
-	return rc;
-}
-
-static void write_pmem(void *pmem_addr, struct page *page,
-		unsigned int off, unsigned int len)
-{
-	void *mem = kmap_atomic(page);
-
-	memcpy_flushcache(pmem_addr, mem + off, len);
-	kunmap_atomic(mem);
-}
-
-static blk_status_t read_pmem(struct page *page, unsigned int off,
-		void *pmem_addr, unsigned int len)
-{
-	int rc;
-	void *mem = kmap_atomic(page);
-
-	rc = memcpy_mcsafe(mem + off, pmem_addr, len);
-	kunmap_atomic(mem);
-	if (rc)
-		return BLK_STS_IOERR;
-	return BLK_STS_OK;
-}
-
-static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
-			unsigned int len, unsigned int off, bool is_write,
-			sector_t sector)
-{
-	blk_status_t rc = BLK_STS_OK;
-	bool bad_pmem = false;
-	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
-	void *pmem_addr = pmem->virt_addr + pmem_off;
-
-	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
-		bad_pmem = true;
-
-	if (!is_write) {
-		if (unlikely(bad_pmem))
-			rc = BLK_STS_IOERR;
-		else {
-			rc = read_pmem(page, off, pmem_addr, len);
-			flush_dcache_page(page);
-		}
-	} else {
-		/*
-		 * Note that we write the data both before and after
-		 * clearing poison.  The write before clear poison
-		 * handles situations where the latest written data is
-		 * preserved and the clear poison operation simply marks
-		 * the address range as valid without changing the data.
-		 * In this case application software can assume that an
-		 * interrupted write will either return the new good
-		 * data or an error.
-		 *
-		 * However, if pmem_clear_poison() leaves the data in an
-		 * indeterminate state we need to perform the write
-		 * after clear poison.
-		 */
-		flush_dcache_page(page);
-		write_pmem(pmem_addr, page, off, len);
-		if (unlikely(bad_pmem)) {
-			rc = pmem_clear_poison(pmem, pmem_off, len);
-			write_pmem(pmem_addr, page, off, len);
-		}
-	}
-
-	return rc;
-}
 
 static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 {
@@ -177,73 +52,12 @@  static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 	return BLK_QC_T_NONE;
 }
 
-static int pmem_rw_page(struct block_device *bdev, sector_t sector,
-		       struct page *page, bool is_write)
-{
-	struct pmem_device *pmem = bdev->bd_queue->queuedata;
-	blk_status_t rc;
-
-	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
-
-	/*
-	 * 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, is_write, 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, void **kaddr, pfn_t *pfn)
-{
-	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
-
-	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
-					PFN_PHYS(nr_pages))))
-		return -EIO;
-	*kaddr = pmem->virt_addr + offset;
-	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
-
-	/*
-	 * If badblocks are present, limit known good range to the
-	 * requested range.
-	 */
-	if (unlikely(pmem->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,
 	.rw_page =		pmem_rw_page,
 	.revalidate_disk =	nvdimm_revalidate_disk,
 };
 
-static long pmem_dax_direct_access(struct dax_device *dax_dev,
-		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
-{
-	struct pmem_device *pmem = dax_get_private(dax_dev);
-
-	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
-}
-
-static size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
-		void *addr, size_t bytes, struct iov_iter *i)
-{
-	return copy_from_iter_flushcache(addr, bytes, i);
-}
-
-static void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff,
-		void *addr, size_t size)
-{
-	arch_wb_cache_pmem(addr, size);
-}
-
 static const struct dax_operations pmem_dax_ops = {
 	.direct_access = pmem_dax_direct_access,
 	.copy_from_iter = pmem_copy_from_iter,
@@ -260,152 +74,37 @@  static void pmem_release_queue(void *q)
 	blk_cleanup_queue(q);
 }
 
-static void pmem_freeze_queue(void *q)
-{
-	blk_freeze_queue_start(q);
-}
-
-static void pmem_release_disk(void *__pmem)
-{
-	struct pmem_device *pmem = __pmem;
-
-	kill_dax(pmem->dax_dev);
-	put_dax(pmem->dax_dev);
-	del_gendisk(pmem->disk);
-	put_disk(pmem->disk);
-}
-
 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);
-	struct vmem_altmap __altmap, *altmap = NULL;
-	int nid = dev_to_node(dev), fua, wbc;
-	struct resource *res = &nsio->res;
-	struct nd_pfn *nd_pfn = NULL;
-	struct dax_device *dax_dev;
-	struct nd_pfn_sb *pfn_sb;
 	struct pmem_device *pmem;
-	struct resource pfn_res;
 	struct request_queue *q;
-	struct device *gendev;
-	struct gendisk *disk;
-	void *addr;
-
-	/* while nsio_rw_bytes is active, parse a pfn info block if present */
-	if (is_nd_pfn(dev)) {
-		nd_pfn = to_nd_pfn(dev);
-		altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
-		if (IS_ERR(altmap))
-			return PTR_ERR(altmap);
-	}
-
-	/* we're attaching a block device, disable raw namespace access */
-	devm_nsio_disable(dev, nsio);
+	int rc;
 
-	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
+	pmem = pmem_core_setup_pmem(dev, ndns);
 	if (!pmem)
-		return -ENOMEM;
-
-	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;
-	}
-	wbc = nvdimm_has_cache(nd_region);
-
-	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;
-	}
+		return -ENXIO;
 
 	q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
 	if (!q)
 		return -ENOMEM;
 
-	if (devm_add_action_or_reset(dev, pmem_release_queue, q))
-		return -ENOMEM;
-
-	pmem->pfn_flags = PFN_DEV;
-	if (is_nd_pfn(dev)) {
-		addr = devm_memremap_pages(dev, &pfn_res, &q->q_usage_counter,
-				altmap);
-		pfn_sb = nd_pfn->pfn_sb;
-		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
-		pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
-		pmem->pfn_flags |= PFN_MAP;
-		res = &pfn_res; /* for badblocks populate */
-		res->start += pmem->data_offset;
-	} else if (pmem_should_map_pages(dev)) {
-		addr = devm_memremap_pages(dev, &nsio->res,
-				&q->q_usage_counter, NULL);
-		pmem->pfn_flags |= PFN_MAP;
-	} else
-		addr = devm_memremap(dev, pmem->phys_addr,
-				pmem->size, ARCH_MEMREMAP_PMEM);
-
-	/*
-	 * At release time the queue must be frozen before
-	 * devm_memremap_pages is unwound
-	 */
-	if (devm_add_action_or_reset(dev, pmem_freeze_queue, q))
-		return -ENOMEM;
-
-	if (IS_ERR(addr))
-		return PTR_ERR(addr);
-	pmem->virt_addr = addr;
-
-	blk_queue_write_cache(q, wbc, fua);
+	pmem->q = q;
+	pmem_core_setup_queue(dev, pmem, ndns);
 	blk_queue_make_request(q, pmem_make_request);
-	blk_queue_physical_block_size(q, PAGE_SIZE);
-	blk_queue_logical_block_size(q, pmem_sector_size(ndns));
 	blk_queue_max_hw_sectors(q, UINT_MAX);
-	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
-	queue_flag_set_unlocked(QUEUE_FLAG_DAX, q);
-	q->queuedata = pmem;
-
-	disk = alloc_disk_node(0, nid);
-	if (!disk)
-		return -ENOMEM;
-	pmem->disk = disk;
-
-	disk->fops		= &pmem_fops;
-	disk->queue		= q;
-	disk->flags		= GENHD_FL_EXT_DEVT;
-	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, res);
-	disk->bb = &pmem->bb;
-
-	dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
-	if (!dax_dev) {
-		put_disk(disk);
-		return -ENOMEM;
-	}
-	dax_write_cache(dax_dev, wbc);
-	pmem->dax_dev = dax_dev;
 
-	gendev = disk_to_dev(disk);
-	gendev->groups = pmem_attribute_groups;
-
-	device_add_disk(dev, disk);
-	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
+	if (devm_add_action_or_reset(dev, pmem_release_queue, q))
 		return -ENOMEM;
 
-	revalidate_disk(disk);
+	rc = pmem_core_remap_pages(dev, pmem, ndns);
+	if (rc < 0)
+		return rc;
 
-	pmem->bb_state = sysfs_get_dirent(disk_to_dev(disk)->kobj.sd,
-					  "badblocks");
-	if (!pmem->bb_state)
-		dev_warn(dev, "'badblocks' notification disabled\n");
+	rc = pmem_core_setup_disk(dev, pmem, ndns, &pmem_fops,
+			&pmem_dax_ops, pmem_attribute_groups);
+	if (rc < 0)
+		return rc;
 
 	return 0;
 }
@@ -436,80 +135,6 @@  static int nd_pmem_probe(struct device *dev)
 	return pmem_attach_disk(dev, ndns);
 }
 
-static int nd_pmem_remove(struct device *dev)
-{
-	struct pmem_device *pmem = dev_get_drvdata(dev);
-
-	if (is_nd_btt(dev))
-		nvdimm_namespace_detach_btt(to_nd_btt(dev));
-	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));
-
-	return 0;
-}
-
-static void nd_pmem_shutdown(struct device *dev)
-{
-	nvdimm_flush(to_nd_region(dev->parent));
-}
-
-static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
-{
-	struct nd_region *nd_region;
-	resource_size_t offset = 0, end_trunc = 0;
-	struct nd_namespace_common *ndns;
-	struct nd_namespace_io *nsio;
-	struct resource res;
-	struct badblocks *bb;
-	struct kernfs_node *bb_state;
-
-	if (event != NVDIMM_REVALIDATE_POISON)
-		return;
-
-	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);
-	}
-
-	res.start = nsio->res.start + offset;
-	res.end = nsio->res.end - end_trunc;
-	nvdimm_badblocks_populate(nd_region, bb, &res);
-	if (bb_state)
-		sysfs_notify_dirent(bb_state);
-}
-
 MODULE_ALIAS("pmem");
 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO);
 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM);
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index 5434321..6df833e 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -4,6 +4,9 @@ 
 #include <linux/types.h>
 #include <linux/pfn_t.h>
 #include <linux/fs.h>
+#include <linux/blk-mq.h>
+#include <linux/dax.h>
+#include "nd.h"
 
 #ifdef CONFIG_ARCH_HAS_PMEM_API
 #define ARCH_MEMREMAP_PMEM MEMREMAP_WB
@@ -35,8 +38,59 @@  struct pmem_device {
 	struct badblocks	bb;
 	struct dax_device	*dax_dev;
 	struct gendisk		*disk;
+	struct blk_mq_tag_set	tag_set;
+	struct request_queue	*q;
 };
 
+static inline 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 inline struct nd_region *to_region(struct pmem_device *pmem)
+{
+	return to_nd_region(to_dev(pmem)->parent);
+}
+
+struct device *to_dev(struct pmem_device *pmem);
+struct nd_region *to_region(struct pmem_device *pmem);
+blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len);
+void write_pmem(void *pmem_addr, struct page *page,
+		unsigned int off, unsigned int len);
+blk_status_t read_pmem(struct page *page, unsigned int off,
+		void *pmem_addr, unsigned int len);
+blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+			unsigned int len, unsigned int off, bool is_write,
+			sector_t sector);
+int pmem_rw_page(struct block_device *bdev, sector_t sector,
+		       struct page *page, bool is_write);
+void nd_pmem_notify(struct device *dev, enum nvdimm_event event);
+long pmem_dax_direct_access(struct dax_device *dax_dev,
+		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn);
+size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i);
+void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t size);
 long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn);
+int nd_pmem_remove(struct device *dev);
+void nd_pmem_shutdown(struct device *dev);
+int pmem_core_remap_pages(struct device *dev,
+		struct pmem_device *pmem, struct nd_namespace_common *ndns);
+int pmem_core_setup_disk(struct device *dev,
+		struct pmem_device *pmem,
+		struct nd_namespace_common *ndns,
+		const struct block_device_operations *block_ops,
+		const struct dax_operations *dax_ops,
+		const struct attribute_group **attrib);
+void pmem_core_setup_queue(struct device *dev, struct pmem_device *pmem,
+		struct nd_namespace_common *ndns);
+struct pmem_device *pmem_core_setup_pmem(struct device *dev,
+		struct nd_namespace_common *ndns);
+
 #endif /* __NVDIMM_PMEM_H__ */
diff --git a/drivers/nvdimm/pmem_core.c b/drivers/nvdimm/pmem_core.c
new file mode 100644
index 0000000..521b61b
--- /dev/null
+++ b/drivers/nvdimm/pmem_core.c
@@ -0,0 +1,451 @@ 
+/*
+ * Persistent Memory Block Driver shared code
+ * Copyright (c) 2014-2017, Intel Corporation.
+ * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
+ * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/badblocks.h>
+#include <linux/memremap.h>
+#include <linux/pfn_t.h>
+#include <linux/uio.h>
+#include "pmem.h"
+#include "pfn.h"
+
+blk_status_t pmem_clear_poison(struct pmem_device *pmem,
+		phys_addr_t offset, unsigned int len)
+{
+	struct device *dev = to_dev(pmem);
+	sector_t sector;
+	long cleared;
+	blk_status_t rc = BLK_STS_OK;
+
+	sector = (offset - pmem->data_offset) / 512;
+
+	cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len);
+	if (cleared < len)
+		rc = BLK_STS_IOERR;
+	if (cleared > 0 && cleared / 512) {
+		cleared /= 512;
+		dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__,
+				(unsigned long long) sector, cleared,
+				cleared > 1 ? "s" : "");
+		badblocks_clear(&pmem->bb, sector, cleared);
+		if (pmem->bb_state)
+			sysfs_notify_dirent(pmem->bb_state);
+	}
+
+	arch_invalidate_pmem(pmem->virt_addr + offset, len);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(pmem_clear_poison);
+
+void write_pmem(void *pmem_addr, struct page *page,
+		unsigned int off, unsigned int len)
+{
+	void *mem = kmap_atomic(page);
+
+	memcpy_flushcache(pmem_addr, mem + off, len);
+	kunmap_atomic(mem);
+}
+EXPORT_SYMBOL_GPL(write_pmem);
+
+blk_status_t read_pmem(struct page *page, unsigned int off,
+		void *pmem_addr, unsigned int len)
+{
+	int rc;
+	void *mem = kmap_atomic(page);
+
+	rc = memcpy_mcsafe(mem + off, pmem_addr, len);
+	kunmap_atomic(mem);
+	if (rc)
+		return BLK_STS_IOERR;
+	return BLK_STS_OK;
+}
+EXPORT_SYMBOL_GPL(read_pmem);
+
+blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
+			unsigned int len, unsigned int off, bool is_write,
+			sector_t sector)
+{
+	blk_status_t rc = BLK_STS_OK;
+	bool bad_pmem = false;
+	phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
+	void *pmem_addr = pmem->virt_addr + pmem_off;
+
+	if (unlikely(is_bad_pmem(&pmem->bb, sector, len)))
+		bad_pmem = true;
+
+	if (!is_write) {
+		if (unlikely(bad_pmem))
+			rc = BLK_STS_IOERR;
+		else {
+			rc = read_pmem(page, off, pmem_addr, len);
+			flush_dcache_page(page);
+		}
+	} else {
+		/*
+		 * Note that we write the data both before and after
+		 * clearing poison.  The write before clear poison
+		 * handles situations where the latest written data is
+		 * preserved and the clear poison operation simply marks
+		 * the address range as valid without changing the data.
+		 * In this case application software can assume that an
+		 * interrupted write will either return the new good
+		 * data or an error.
+		 *
+		 * However, if pmem_clear_poison() leaves the data in an
+		 * indeterminate state we need to perform the write
+		 * after clear poison.
+		 */
+		flush_dcache_page(page);
+		write_pmem(pmem_addr, page, off, len);
+		if (unlikely(bad_pmem)) {
+			rc = pmem_clear_poison(pmem, pmem_off, len);
+			write_pmem(pmem_addr, page, off, len);
+		}
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(pmem_do_bvec);
+
+int pmem_rw_page(struct block_device *bdev, sector_t sector,
+		       struct page *page, bool is_write)
+{
+	struct pmem_device *pmem = bdev->bd_queue->queuedata;
+	blk_status_t rc;
+
+	rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, is_write, sector);
+
+	/*
+	 * 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, is_write, 0);
+
+	return blk_status_to_errno(rc);
+}
+EXPORT_SYMBOL_GPL(pmem_rw_page);
+
+/* 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, void **kaddr, pfn_t *pfn)
+{
+	resource_size_t offset = PFN_PHYS(pgoff) + pmem->data_offset;
+
+	if (unlikely(is_bad_pmem(&pmem->bb, PFN_PHYS(pgoff) / 512,
+					PFN_PHYS(nr_pages))))
+		return -EIO;
+	*kaddr = pmem->virt_addr + offset;
+	*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
+
+	/*
+	 * If badblocks are present, limit known good range to the
+	 * requested range.
+	 */
+	if (unlikely(pmem->bb.count))
+		return nr_pages;
+	return PHYS_PFN(pmem->size - pmem->pfn_pad - offset);
+}
+
+long pmem_dax_direct_access(struct dax_device *dax_dev,
+		pgoff_t pgoff, long nr_pages, void **kaddr, pfn_t *pfn)
+{
+	struct pmem_device *pmem = dax_get_private(dax_dev);
+
+	return __pmem_direct_access(pmem, pgoff, nr_pages, kaddr, pfn);
+}
+EXPORT_SYMBOL_GPL(pmem_dax_direct_access);
+
+size_t pmem_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t bytes, struct iov_iter *i)
+{
+	return copy_from_iter_flushcache(addr, bytes, i);
+}
+EXPORT_SYMBOL_GPL(pmem_copy_from_iter);
+
+void pmem_dax_flush(struct dax_device *dax_dev, pgoff_t pgoff,
+		void *addr, size_t size)
+{
+	arch_wb_cache_pmem(addr, size);
+}
+EXPORT_SYMBOL_GPL(pmem_dax_flush);
+
+void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
+{
+	struct nd_region *nd_region;
+	resource_size_t offset = 0, end_trunc = 0;
+	struct nd_namespace_common *ndns;
+	struct nd_namespace_io *nsio;
+	struct resource res;
+	struct badblocks *bb;
+	struct kernfs_node *bb_state;
+
+	if (event != NVDIMM_REVALIDATE_POISON)
+		return;
+
+	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);
+	}
+
+	res.start = nsio->res.start + offset;
+	res.end = nsio->res.end - end_trunc;
+	nvdimm_badblocks_populate(nd_region, bb, &res);
+	if (bb_state)
+		sysfs_notify_dirent(bb_state);
+}
+EXPORT_SYMBOL_GPL(nd_pmem_notify);
+
+static void pmem_freeze_queue(void *q)
+{
+	blk_freeze_queue_start(q);
+}
+
+int pmem_core_remap_pages(struct device *dev, struct pmem_device *pmem,
+		struct nd_namespace_common *ndns)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	void *addr;
+	struct nd_pfn_sb *pfn_sb;
+	struct nd_pfn *nd_pfn = NULL;
+	struct resource *res = &nsio->res;
+	struct resource pfn_res;
+	struct vmem_altmap __altmap, *altmap = NULL;
+
+	/* while nsio_rw_bytes is active, parse a pfn info block if present */
+	if (is_nd_pfn(dev)) {
+		nd_pfn = to_nd_pfn(dev);
+		altmap = nvdimm_setup_pfn(nd_pfn, &pfn_res, &__altmap);
+		if (IS_ERR(altmap))
+			return PTR_ERR(altmap);
+	}
+
+	pmem->pfn_flags = PFN_DEV;
+	if (is_nd_pfn(dev)) {
+		addr = devm_memremap_pages(dev, &pfn_res,
+				&pmem->q->q_usage_counter, altmap);
+		pfn_sb = nd_pfn->pfn_sb;
+		pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
+		pmem->pfn_pad = resource_size(res) - resource_size(&pfn_res);
+		pmem->pfn_flags |= PFN_MAP;
+		res = &pfn_res; /* for badblocks populate */
+		res->start += pmem->data_offset;
+	} else if (pmem_should_map_pages(dev)) {
+		addr = devm_memremap_pages(dev, &nsio->res,
+				&pmem->q->q_usage_counter, NULL);
+		pmem->pfn_flags |= PFN_MAP;
+	} else
+		addr = devm_memremap(dev, pmem->phys_addr,
+				pmem->size, ARCH_MEMREMAP_PMEM);
+
+	/*
+	 * At release time the queue must be frozen before
+	 * devm_memremap_pages is unwound
+	 */
+	if (devm_add_action_or_reset(dev, pmem_freeze_queue, pmem->q))
+		return -ENXIO;
+
+	if (IS_ERR(addr))
+		return -ENXIO;
+
+	pmem->virt_addr = addr;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pmem_core_remap_pages);
+
+static void pmem_release_disk(void *__pmem)
+{
+	struct pmem_device *pmem = __pmem;
+
+	kill_dax(pmem->dax_dev);
+	put_dax(pmem->dax_dev);
+	del_gendisk(pmem->disk);
+	put_disk(pmem->disk);
+}
+
+int pmem_core_setup_disk(struct device *dev,
+		struct pmem_device *pmem,
+		struct nd_namespace_common *ndns,
+		const struct block_device_operations *block_ops,
+		const struct dax_operations *dax_ops,
+		const struct attribute_group **attribs)
+{
+	struct device *gendev;
+	struct gendisk *disk;
+	struct dax_device *dax_dev;
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	int wbc, fua;
+	int nid = dev_to_node(dev);
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	struct resource *res = &nsio->res;
+
+	wbc = nvdimm_has_cache(nd_region);
+	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;
+	}
+
+	disk = alloc_disk_node(0, nid);
+	if (!disk)
+		return -ENOMEM;
+	pmem->disk = disk;
+
+	disk->fops = block_ops;
+	disk->queue = pmem->q;
+	disk->flags = GENHD_FL_EXT_DEVT;
+	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 -ENXIO;
+
+	nvdimm_badblocks_populate(nd_region, &pmem->bb, res);
+	disk->bb = &pmem->bb;
+
+	dax_dev = alloc_dax(pmem, disk->disk_name, dax_ops);
+	if (!dax_dev) {
+		put_disk(disk);
+		return -ENOMEM;
+	}
+
+	dax_write_cache(dax_dev, wbc);
+	pmem->dax_dev = dax_dev;
+	gendev = disk_to_dev(disk);
+	gendev->groups = attribs;
+
+	device_add_disk(dev, disk);
+	if (devm_add_action_or_reset(dev, pmem_release_disk, pmem))
+		return -ENOMEM;
+
+	revalidate_disk(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;
+}
+EXPORT_SYMBOL_GPL(pmem_core_setup_disk);
+
+void pmem_core_setup_queue(struct device *dev, struct pmem_device *pmem,
+		struct nd_namespace_common *ndns)
+{
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	int fua, wbc;
+
+	wbc = nvdimm_has_cache(nd_region);
+	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;
+	}
+
+	blk_queue_write_cache(pmem->q, wbc, fua);
+	blk_queue_physical_block_size(pmem->q, PAGE_SIZE);
+	blk_queue_logical_block_size(pmem->q, pmem_sector_size(ndns));
+	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->q);
+	queue_flag_set_unlocked(QUEUE_FLAG_DAX, pmem->q);
+	pmem->q->queuedata = pmem;
+}
+EXPORT_SYMBOL_GPL(pmem_core_setup_queue);
+
+struct pmem_device *pmem_core_setup_pmem(struct device *dev,
+		struct nd_namespace_common *ndns)
+{
+	struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+	struct resource *res = &nsio->res;
+	struct pmem_device *pmem;
+
+	/* we're attaching a block device, disable raw namespace access */
+	devm_nsio_disable(dev, nsio);
+
+	pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
+	if (!pmem)
+		return NULL;
+
+	dev_set_drvdata(dev, pmem);
+	pmem->phys_addr = res->start;
+	pmem->size = resource_size(res);
+	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 NULL;
+	}
+
+
+	return pmem;
+}
+EXPORT_SYMBOL_GPL(pmem_core_setup_pmem);
+
+int nd_pmem_remove(struct device *dev)
+{
+	struct pmem_device *pmem = dev_get_drvdata(dev);
+
+	if (is_nd_btt(dev))
+		nvdimm_namespace_detach_btt(to_nd_btt(dev));
+	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));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nd_pmem_remove);
+
+void nd_pmem_shutdown(struct device *dev)
+{
+	nvdimm_flush(to_nd_region(dev->parent));
+}
+EXPORT_SYMBOL_GPL(nd_pmem_shutdown);
+
+MODULE_LICENSE("GPL v2");