Merge branch 'for-4.7/dax' into libnvdimm-for-next

16 files changed, 803 insertions, 586 deletions

diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index 53c11621d5b1..7c8a3bf07884 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -88,4 +88,17 @@ config NVDIMM_PFN
 
           Select Y if unsure
 
+config NVDIMM_DAX
+        bool "NVDIMM DAX: Raw access to persistent memory"
+        default LIBNVDIMM
+        depends on NVDIMM_PFN
+        help
+          Support raw device dax access to a persistent memory
+          namespace.  For environments that want to hard partition
+          peristent memory, this capability provides a mechanism to
+          sub-divide a namespace into character devices that can only be
+          accessed via DAX (mmap(2)).
+
+          Select Y if unsure
+
 endif
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index ea84d3c4e8e5..909554c3f955 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -23,3 +23,4 @@ libnvdimm-y += label.o
 libnvdimm-$(CONFIG_ND_CLAIM) += claim.o
 libnvdimm-$(CONFIG_BTT) += btt_devs.o
 libnvdimm-$(CONFIG_NVDIMM_PFN) += pfn_devs.o
+libnvdimm-$(CONFIG_NVDIMM_DAX) += dax_devs.o
diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index e9ff9229d942..495e06d9f7e7 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -21,19 +21,19 @@
 #include <linux/sizes.h>
 #include "nd.h"
 
-struct nd_blk_device {
-        struct request_queue *queue;
-        struct gendisk *disk;
-        struct nd_namespace_blk *nsblk;
-        struct nd_blk_region *ndbr;
-        size_t disk_size;
-        u32 sector_size;
-        u32 internal_lbasize;
-};
+static u32 nsblk_meta_size(struct nd_namespace_blk *nsblk)
+{
+        return nsblk->lbasize - ((nsblk->lbasize >= 4096) ? 4096 : 512);
+}
+
+static u32 nsblk_internal_lbasize(struct nd_namespace_blk *nsblk)
+{
+        return roundup(nsblk->lbasize, INT_LBASIZE_ALIGNMENT);
+}
 
-static u32 nd_blk_meta_size(struct nd_blk_device *blk_dev)
+static u32 nsblk_sector_size(struct nd_namespace_blk *nsblk)
 {
-        return blk_dev->nsblk->lbasize - blk_dev->sector_size;
+        return nsblk->lbasize - nsblk_meta_size(nsblk);
 }
 
 static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
@@ -57,20 +57,29 @@ static resource_size_t to_dev_offset(struct nd_namespace_blk *nsblk,
         return SIZE_MAX;
 }
 
+static struct nd_blk_region *to_ndbr(struct nd_namespace_blk *nsblk)
+{
+        struct nd_region *nd_region;
+        struct device *parent;
+
+        parent = nsblk->common.dev.parent;
+        nd_region = container_of(parent, struct nd_region, dev);
+        return container_of(nd_region, struct nd_blk_region, nd_region);
+}
+
 #ifdef CONFIG_BLK_DEV_INTEGRITY
-static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
-                                struct bio_integrity_payload *bip, u64 lba,
-                                int rw)
+static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
+                struct bio_integrity_payload *bip, u64 lba, int rw)
 {
-        unsigned int len = nd_blk_meta_size(blk_dev);
+        struct nd_blk_region *ndbr = to_ndbr(nsblk);
+        unsigned int len = nsblk_meta_size(nsblk);
         resource_size_t dev_offset, ns_offset;
-        struct nd_namespace_blk *nsblk;
-        struct nd_blk_region *ndbr;
+        u32 internal_lbasize, sector_size;
         int err = 0;
 
-        nsblk = blk_dev->nsblk;
-        ndbr = blk_dev->ndbr;
-        ns_offset = lba * blk_dev->internal_lbasize + blk_dev->sector_size;
+        internal_lbasize = nsblk_internal_lbasize(nsblk);
+        sector_size = nsblk_sector_size(nsblk);
+        ns_offset = lba * internal_lbasize + sector_size;
         dev_offset = to_dev_offset(nsblk, ns_offset, len);
         if (dev_offset == SIZE_MAX)
                 return -EIO;
@@ -104,25 +113,26 @@ static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
 }
 
 #else /* CONFIG_BLK_DEV_INTEGRITY */
-static int nd_blk_rw_integrity(struct nd_blk_device *blk_dev,
-                                struct bio_integrity_payload *bip, u64 lba,
-                                int rw)
+static int nd_blk_rw_integrity(struct nd_namespace_blk *nsblk,
+                struct bio_integrity_payload *bip, u64 lba, int rw)
 {
         return 0;
 }
 #endif
 
-static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
-                        struct bio_integrity_payload *bip, struct page *page,
-                        unsigned int len, unsigned int off, int rw,
-                        sector_t sector)
+static int nsblk_do_bvec(struct nd_namespace_blk *nsblk,
+                struct bio_integrity_payload *bip, struct page *page,
+                unsigned int len, unsigned int off, int rw, sector_t sector)
 {
-        struct nd_blk_region *ndbr = blk_dev->ndbr;
+        struct nd_blk_region *ndbr = to_ndbr(nsblk);
         resource_size_t dev_offset, ns_offset;
+        u32 internal_lbasize, sector_size;
         int err = 0;
         void *iobuf;
         u64 lba;
 
+        internal_lbasize = nsblk_internal_lbasize(nsblk);
+        sector_size = nsblk_sector_size(nsblk);
         while (len) {
                 unsigned int cur_len;
 
@@ -132,11 +142,11 @@ static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
                  * Block Window setup/move steps. the do_io routine is capable
                  * of handling len <= PAGE_SIZE.
                  */
-                cur_len = bip ? min(len, blk_dev->sector_size) : len;
+                cur_len = bip ? min(len, sector_size) : len;
 
-                lba = div_u64(sector << SECTOR_SHIFT, blk_dev->sector_size);
-                ns_offset = lba * blk_dev->internal_lbasize;
-                dev_offset = to_dev_offset(blk_dev->nsblk, ns_offset, cur_len);
+                lba = div_u64(sector << SECTOR_SHIFT, sector_size);
+                ns_offset = lba * internal_lbasize;
+                dev_offset = to_dev_offset(nsblk, ns_offset, cur_len);
                 if (dev_offset == SIZE_MAX)
                         return -EIO;
 
@@ -147,13 +157,13 @@ static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
                         return err;
 
                 if (bip) {
-                        err = nd_blk_rw_integrity(blk_dev, bip, lba, rw);
+                        err = nd_blk_rw_integrity(nsblk, bip, lba, rw);
                         if (err)
                                 return err;
                 }
                 len -= cur_len;
                 off += cur_len;
-                sector += blk_dev->sector_size >> SECTOR_SHIFT;
+                sector += sector_size >> SECTOR_SHIFT;
         }
 
         return err;
@@ -161,10 +171,8 @@ static int nd_blk_do_bvec(struct nd_blk_device *blk_dev,
 
 static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
 {
-        struct block_device *bdev = bio->bi_bdev;
-        struct gendisk *disk = bdev->bd_disk;
         struct bio_integrity_payload *bip;
-        struct nd_blk_device *blk_dev;
+        struct nd_namespace_blk *nsblk;
         struct bvec_iter iter;
         unsigned long start;
         struct bio_vec bvec;
@@ -183,17 +191,17 @@ static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
         }
 
         bip = bio_integrity(bio);
-        blk_dev = disk->private_data;
+        nsblk = q->queuedata;
         rw = bio_data_dir(bio);
         do_acct = nd_iostat_start(bio, &start);
         bio_for_each_segment(bvec, bio, iter) {
                 unsigned int len = bvec.bv_len;
 
                 BUG_ON(len > PAGE_SIZE);
-                err = nd_blk_do_bvec(blk_dev, bip, bvec.bv_page, len,
-                                        bvec.bv_offset, rw, iter.bi_sector);
+                err = nsblk_do_bvec(nsblk, bip, bvec.bv_page, len,
+                                bvec.bv_offset, rw, iter.bi_sector);
                 if (err) {
-                        dev_info(&blk_dev->nsblk->common.dev,
+                        dev_dbg(&nsblk->common.dev,
                                         "io error in %s sector %lld, len %d,\n",
                                         (rw == READ) ? "READ" : "WRITE",
                                         (unsigned long long) iter.bi_sector, len);
@@ -209,17 +217,16 @@ static blk_qc_t nd_blk_make_request(struct request_queue *q, struct bio *bio)
         return BLK_QC_T_NONE;
 }
 
-static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
+static int nsblk_rw_bytes(struct nd_namespace_common *ndns,
                 resource_size_t offset, void *iobuf, size_t n, int rw)
 {
-        struct nd_blk_device *blk_dev = dev_get_drvdata(ndns->claim);
-        struct nd_namespace_blk *nsblk = blk_dev->nsblk;
-        struct nd_blk_region *ndbr = blk_dev->ndbr;
+        struct nd_namespace_blk *nsblk = to_nd_namespace_blk(&ndns->dev);
+        struct nd_blk_region *ndbr = to_ndbr(nsblk);
         resource_size_t dev_offset;
 
         dev_offset = to_dev_offset(nsblk, offset, n);
 
-        if (unlikely(offset + n > blk_dev->disk_size)) {
+        if (unlikely(offset + n > nsblk->size)) {
                 dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
                 return -EFAULT;
         }
@@ -235,51 +242,65 @@ static const struct block_device_operations nd_blk_fops = {
         .revalidate_disk = nvdimm_revalidate_disk,
 };
 
-static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
-                struct nd_blk_device *blk_dev)
+static void nd_blk_release_queue(void *q)
+{
+        blk_cleanup_queue(q);
+}
+
+static void nd_blk_release_disk(void *disk)
+{
+        del_gendisk(disk);
+        put_disk(disk);
+}
+
+static int nsblk_attach_disk(struct nd_namespace_blk *nsblk)
 {
+        struct device *dev = &nsblk->common.dev;
         resource_size_t available_disk_size;
+        struct request_queue *q;
         struct gendisk *disk;
         u64 internal_nlba;
 
-        internal_nlba = div_u64(blk_dev->disk_size, blk_dev->internal_lbasize);
-        available_disk_size = internal_nlba * blk_dev->sector_size;
+        internal_nlba = div_u64(nsblk->size, nsblk_internal_lbasize(nsblk));
+        available_disk_size = internal_nlba * nsblk_sector_size(nsblk);
 
-        blk_dev->queue = blk_alloc_queue(GFP_KERNEL);
-        if (!blk_dev->queue)
+        q = blk_alloc_queue(GFP_KERNEL);
+        if (!q)
                 return -ENOMEM;
+        if (devm_add_action(dev, nd_blk_release_queue, q)) {
+                blk_cleanup_queue(q);
+                return -ENOMEM;
+        }
 
-        blk_queue_make_request(blk_dev->queue, nd_blk_make_request);
-        blk_queue_max_hw_sectors(blk_dev->queue, UINT_MAX);
-        blk_queue_bounce_limit(blk_dev->queue, BLK_BOUNCE_ANY);
-        blk_queue_logical_block_size(blk_dev->queue, blk_dev->sector_size);
-        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, blk_dev->queue);
+        blk_queue_make_request(q, nd_blk_make_request);
+        blk_queue_max_hw_sectors(q, UINT_MAX);
+        blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
+        blk_queue_logical_block_size(q, nsblk_sector_size(nsblk));
+        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
+        q->queuedata = nsblk;
 
-        disk = blk_dev->disk = alloc_disk(0);
-        if (!disk) {
-                blk_cleanup_queue(blk_dev->queue);
+        disk = alloc_disk(0);
+        if (!disk)
+                return -ENOMEM;
+        if (devm_add_action(dev, nd_blk_release_disk, disk)) {
+                put_disk(disk);
                 return -ENOMEM;
         }
 
-        disk->driverfs_dev      = &ndns->dev;
+        disk->driverfs_dev      = dev;
         disk->first_minor       = 0;
         disk->fops              = &nd_blk_fops;
-        disk->private_data      = blk_dev;
-        disk->queue             = blk_dev->queue;
+        disk->queue             = q;
         disk->flags             = GENHD_FL_EXT_DEVT;
-        nvdimm_namespace_disk_name(ndns, disk->disk_name);
+        nvdimm_namespace_disk_name(&nsblk->common, disk->disk_name);
         set_capacity(disk, 0);
         add_disk(disk);
 
-        if (nd_blk_meta_size(blk_dev)) {
-                int rc = nd_integrity_init(disk, nd_blk_meta_size(blk_dev));
+        if (nsblk_meta_size(nsblk)) {
+                int rc = nd_integrity_init(disk, nsblk_meta_size(nsblk));
 
-                if (rc) {
-                        del_gendisk(disk);
-                        put_disk(disk);
-                        blk_cleanup_queue(blk_dev->queue);
+                if (rc)
                         return rc;
-                }
         }
 
         set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
@@ -291,56 +312,29 @@ static int nd_blk_probe(struct device *dev)
 {
         struct nd_namespace_common *ndns;
         struct nd_namespace_blk *nsblk;
-        struct nd_blk_device *blk_dev;
-        int rc;
 
         ndns = nvdimm_namespace_common_probe(dev);
         if (IS_ERR(ndns))
                 return PTR_ERR(ndns);
 
-        blk_dev = kzalloc(sizeof(*blk_dev), GFP_KERNEL);
-        if (!blk_dev)
-                return -ENOMEM;
-
         nsblk = to_nd_namespace_blk(&ndns->dev);
-        blk_dev->disk_size = nvdimm_namespace_capacity(ndns);
-        blk_dev->ndbr = to_nd_blk_region(dev->parent);
-        blk_dev->nsblk = to_nd_namespace_blk(&ndns->dev);
-        blk_dev->internal_lbasize = roundup(nsblk->lbasize,
-                                                INT_LBASIZE_ALIGNMENT);
-        blk_dev->sector_size = ((nsblk->lbasize >= 4096) ? 4096 : 512);
-        dev_set_drvdata(dev, blk_dev);
-
-        ndns->rw_bytes = nd_blk_rw_bytes;
+        nsblk->size = nvdimm_namespace_capacity(ndns);
+        dev_set_drvdata(dev, nsblk);
+
+        ndns->rw_bytes = nsblk_rw_bytes;
         if (is_nd_btt(dev))
-                rc = nvdimm_namespace_attach_btt(ndns);
-        else if (nd_btt_probe(ndns, blk_dev) == 0) {
+                return nvdimm_namespace_attach_btt(ndns);
+        else if (nd_btt_probe(dev, ndns) == 0) {
                 /* we'll come back as btt-blk */
-                rc = -ENXIO;
+                return -ENXIO;
         } else
-                rc = nd_blk_attach_disk(ndns, blk_dev);
-        if (rc)
-                kfree(blk_dev);
-        return rc;
-}
-
-static void nd_blk_detach_disk(struct nd_blk_device *blk_dev)
-{
-        del_gendisk(blk_dev->disk);
-        put_disk(blk_dev->disk);
-        blk_cleanup_queue(blk_dev->queue);
+                return nsblk_attach_disk(nsblk);
 }
 
 static int nd_blk_remove(struct device *dev)
 {
-        struct nd_blk_device *blk_dev = dev_get_drvdata(dev);
-
         if (is_nd_btt(dev))
-                nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
-        else
-                nd_blk_detach_disk(blk_dev);
-        kfree(blk_dev);
-
+                nvdimm_namespace_detach_btt(to_nd_btt(dev));
         return 0;
 }
 
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index f068b6513cd2..cc9fafed9362 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1306,7 +1306,7 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
         struct btt *btt;
         struct device *dev = &nd_btt->dev;
 
-        btt = kzalloc(sizeof(struct btt), GFP_KERNEL);
+        btt = devm_kzalloc(dev, sizeof(struct btt), GFP_KERNEL);
         if (!btt)
                 return NULL;
 
@@ -1321,13 +1321,13 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
         ret = discover_arenas(btt);
         if (ret) {
                 dev_err(dev, "init: error in arena_discover: %d\n", ret);
-                goto out_free;
+                return NULL;
         }
 
         if (btt->init_state != INIT_READY && nd_region->ro) {
                 dev_info(dev, "%s is read-only, unable to init btt metadata\n",
                                 dev_name(&nd_region->dev));
-                goto out_free;
+                return NULL;
         } else if (btt->init_state != INIT_READY) {
                 btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
                         ((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
@@ -1337,29 +1337,25 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
                 ret = create_arenas(btt);
                 if (ret) {
                         dev_info(dev, "init: create_arenas: %d\n", ret);
-                        goto out_free;
+                        return NULL;
                 }
 
                 ret = btt_meta_init(btt);
                 if (ret) {
                         dev_err(dev, "init: error in meta_init: %d\n", ret);
-                        goto out_free;
+                        return NULL;
                 }
         }
 
         ret = btt_blk_init(btt);
         if (ret) {
                 dev_err(dev, "init: error in blk_init: %d\n", ret);
-                goto out_free;
+                return NULL;
         }
 
         btt_debugfs_init(btt);
 
         return btt;
-
- out_free:
-        kfree(btt);
-        return NULL;
 }
 
 /**
@@ -1377,7 +1373,6 @@ static void btt_fini(struct btt *btt)
                 btt_blk_cleanup(btt);
                 free_arenas(btt);
                 debugfs_remove_recursive(btt->debugfs_dir);
-                kfree(btt);
         }
 }
 
@@ -1406,9 +1401,8 @@ int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns)
 }
 EXPORT_SYMBOL(nvdimm_namespace_attach_btt);
 
-int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns)
+int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt)
 {
-        struct nd_btt *nd_btt = to_nd_btt(ndns->claim);
         struct btt *btt = nd_btt->btt;
 
         btt_fini(btt);
diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c
index cb477518dd0e..816d0dae6398 100644
--- a/drivers/nvdimm/btt_devs.c
+++ b/drivers/nvdimm/btt_devs.c
@@ -273,10 +273,10 @@ static int __nd_btt_probe(struct nd_btt *nd_btt,
         return 0;
 }
 
-int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
+int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns)
 {
         int rc;
-        struct device *dev;
+        struct device *btt_dev;
         struct btt_sb *btt_sb;
         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 
@@ -284,21 +284,19 @@ int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
                 return -ENODEV;
 
         nvdimm_bus_lock(&ndns->dev);
-        dev = __nd_btt_create(nd_region, 0, NULL, ndns);
+        btt_dev = __nd_btt_create(nd_region, 0, NULL, ndns);
         nvdimm_bus_unlock(&ndns->dev);
-        if (!dev)
+        if (!btt_dev)
                 return -ENOMEM;
-        dev_set_drvdata(dev, drvdata);
-        btt_sb = kzalloc(sizeof(*btt_sb), GFP_KERNEL);
-        rc = __nd_btt_probe(to_nd_btt(dev), ndns, btt_sb);
-        kfree(btt_sb);
-        dev_dbg(&ndns->dev, "%s: btt: %s\n", __func__,
-                        rc == 0 ? dev_name(dev) : "<none>");
+        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>");
         if (rc < 0) {
-                struct nd_btt *nd_btt = to_nd_btt(dev);
+                struct nd_btt *nd_btt = to_nd_btt(btt_dev);
 
-                __nd_detach_ndns(dev, &nd_btt->ndns);
-                put_device(dev);
+                __nd_detach_ndns(btt_dev, &nd_btt->ndns);
+                put_device(btt_dev);
         }
 
         return rc;
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 19f822d7f652..97589e3cb852 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -40,6 +40,8 @@ static int to_nd_device_type(struct device *dev)
                 return ND_DEVICE_REGION_PMEM;
         else if (is_nd_blk(dev))
                 return ND_DEVICE_REGION_BLK;
+        else if (is_nd_dax(dev))
+                return ND_DEVICE_DAX_PMEM;
         else if (is_nd_pmem(dev->parent) || is_nd_blk(dev->parent))
                 return nd_region_to_nstype(to_nd_region(dev->parent));
 
@@ -246,6 +248,8 @@ static void nd_async_device_unregister(void *d, async_cookie_t cookie)
 
 void __nd_device_register(struct device *dev)
 {
+        if (!dev)
+                return;
         dev->bus = &nvdimm_bus_type;
         get_device(dev);
         async_schedule_domain(nd_async_device_register, dev,
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index e8f03b0e95e4..5f53db59a058 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -12,6 +12,7 @@
  */
 #include <linux/device.h>
 #include <linux/sizes.h>
+#include <linux/pmem.h>
 #include "nd-core.h"
 #include "pfn.h"
 #include "btt.h"
@@ -84,6 +85,8 @@ static bool is_idle(struct device *dev, struct nd_namespace_common *ndns)
                 seed = nd_region->btt_seed;
         else if (is_nd_pfn(dev))
                 seed = nd_region->pfn_seed;
+        else if (is_nd_dax(dev))
+                seed = nd_region->dax_seed;
 
         if (seed == dev || ndns || dev->driver)
                 return false;
@@ -199,3 +202,63 @@ u64 nd_sb_checksum(struct nd_gen_sb *nd_gen_sb)
         return sum;
 }
 EXPORT_SYMBOL(nd_sb_checksum);
+
+static int nsio_rw_bytes(struct nd_namespace_common *ndns,
+                resource_size_t offset, void *buf, size_t size, int rw)
+{
+        struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+
+        if (unlikely(offset + size > nsio->size)) {
+                dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
+                return -EFAULT;
+        }
+
+        if (rw == READ) {
+                unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
+
+                if (unlikely(is_bad_pmem(&nsio->bb, offset / 512, sz_align)))
+                        return -EIO;
+                return memcpy_from_pmem(buf, nsio->addr + offset, size);
+        } else {
+                memcpy_to_pmem(nsio->addr + offset, buf, size);
+                wmb_pmem();
+        }
+
+        return 0;
+}
+
+int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio)
+{
+        struct resource *res = &nsio->res;
+        struct nd_namespace_common *ndns = &nsio->common;
+
+        nsio->size = resource_size(res);
+        if (!devm_request_mem_region(dev, res->start, resource_size(res),
+                                dev_name(dev))) {
+                dev_warn(dev, "could not reserve region %pR\n", res);
+                return -EBUSY;
+        }
+
+        ndns->rw_bytes = nsio_rw_bytes;
+        if (devm_init_badblocks(dev, &nsio->bb))
+                return -ENOMEM;
+        nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb,
+                        &nsio->res);
+
+        nsio->addr = devm_memremap(dev, res->start, resource_size(res),
+                        ARCH_MEMREMAP_PMEM);
+        if (IS_ERR(nsio->addr))
+                return PTR_ERR(nsio->addr);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(devm_nsio_enable);
+
+void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio)
+{
+        struct resource *res = &nsio->res;
+
+        devm_memunmap(dev, nsio->addr);
+        devm_exit_badblocks(dev, &nsio->bb);
+        devm_release_mem_region(dev, res->start, resource_size(res));
+}
+EXPORT_SYMBOL_GPL(devm_nsio_disable);
diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
new file mode 100644
index 000000000000..f90f7549e7f4
--- /dev/null
+++ b/drivers/nvdimm/dax_devs.c
@@ -0,0 +1,99 @@
+/*
+ * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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/device.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include "nd-core.h"
+#include "nd.h"
+
+static void nd_dax_release(struct device *dev)
+{
+        struct nd_region *nd_region = to_nd_region(dev->parent);
+        struct nd_dax *nd_dax = to_nd_dax(dev);
+        struct nd_pfn *nd_pfn = &nd_dax->nd_pfn;
+
+        dev_dbg(dev, "%s\n", __func__);
+        nd_detach_ndns(dev, &nd_pfn->ndns);
+        ida_simple_remove(&nd_region->dax_ida, nd_pfn->id);
+        kfree(nd_pfn->uuid);
+        kfree(nd_dax);
+}
+
+static struct device_type nd_dax_device_type = {
+        .name = "nd_dax",
+        .release = nd_dax_release,
+};
+
+bool is_nd_dax(struct device *dev)
+{
+        return dev ? dev->type == &nd_dax_device_type : false;
+}
+EXPORT_SYMBOL(is_nd_dax);
+
+struct nd_dax *to_nd_dax(struct device *dev)
+{
+        struct nd_dax *nd_dax = container_of(dev, struct nd_dax, nd_pfn.dev);
+
+        WARN_ON(!is_nd_dax(dev));
+        return nd_dax;
+}
+EXPORT_SYMBOL(to_nd_dax);
+
+static const struct attribute_group *nd_dax_attribute_groups[] = {
+        &nd_pfn_attribute_group,
+        &nd_device_attribute_group,
+        &nd_numa_attribute_group,
+        NULL,
+};
+
+static struct nd_dax *nd_dax_alloc(struct nd_region *nd_region)
+{
+        struct nd_pfn *nd_pfn;
+        struct nd_dax *nd_dax;
+        struct device *dev;
+
+        nd_dax = kzalloc(sizeof(*nd_dax), GFP_KERNEL);
+        if (!nd_dax)
+                return NULL;
+
+        nd_pfn = &nd_dax->nd_pfn;
+        nd_pfn->id = ida_simple_get(&nd_region->dax_ida, 0, 0, GFP_KERNEL);
+        if (nd_pfn->id < 0) {
+                kfree(nd_dax);
+                return NULL;
+        }
+
+        dev = &nd_pfn->dev;
+        dev_set_name(dev, "dax%d.%d", nd_region->id, nd_pfn->id);
+        dev->groups = nd_dax_attribute_groups;
+        dev->type = &nd_dax_device_type;
+        dev->parent = &nd_region->dev;
+
+        return nd_dax;
+}
+
+struct device *nd_dax_create(struct nd_region *nd_region)
+{
+        struct device *dev = NULL;
+        struct nd_dax *nd_dax;
+
+        if (!is_nd_pmem(&nd_region->dev))
+                return NULL;
+
+        nd_dax = nd_dax_alloc(nd_region);
+        if (nd_dax)
+                dev = nd_pfn_devinit(&nd_dax->nd_pfn, NULL);
+        __nd_device_register(dev);
+        return dev;
+}
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index f5cb88601359..c5e3196c45b0 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1288,6 +1288,8 @@ static ssize_t mode_show(struct device *dev,
                 mode = "safe";
         else if (claim && is_nd_pfn(claim))
                 mode = "memory";
+        else if (claim && is_nd_dax(claim))
+                mode = "dax";
         else if (!claim && pmem_should_map_pages(dev))
                 mode = "memory";
         else
@@ -1379,21 +1381,19 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
 {
         struct nd_btt *nd_btt = is_nd_btt(dev) ? to_nd_btt(dev) : NULL;
         struct nd_pfn *nd_pfn = is_nd_pfn(dev) ? to_nd_pfn(dev) : NULL;
-        struct nd_namespace_common *ndns;
+        struct nd_dax *nd_dax = is_nd_dax(dev) ? to_nd_dax(dev) : NULL;
+        struct nd_namespace_common *ndns = NULL;
         resource_size_t size;
 
-        if (nd_btt || nd_pfn) {
-                struct device *host = NULL;
-
-                if (nd_btt) {
-                        host = &nd_btt->dev;
+        if (nd_btt || nd_pfn || nd_dax) {
+                if (nd_btt)
                         ndns = nd_btt->ndns;
-                } else if (nd_pfn) {
-                        host = &nd_pfn->dev;
+                else if (nd_pfn)
                         ndns = nd_pfn->ndns;
-                }
+                else if (nd_dax)
+                        ndns = nd_dax->nd_pfn.ndns;
 
-                if (!ndns || !host)
+                if (!ndns)
                         return ERR_PTR(-ENODEV);
 
                 /*
@@ -1404,12 +1404,12 @@ struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev)
                 device_unlock(&ndns->dev);
                 if (ndns->dev.driver) {
                         dev_dbg(&ndns->dev, "is active, can't bind %s\n",
-                                        dev_name(host));
+                                        dev_name(dev));
                         return ERR_PTR(-EBUSY);
                 }
-                if (dev_WARN_ONCE(&ndns->dev, ndns->claim != host,
+                if (dev_WARN_ONCE(&ndns->dev, ndns->claim != dev,
                                         "host (%s) vs claim (%s) mismatch\n",
-                                        dev_name(host),
+                                        dev_name(dev),
                                         dev_name(ndns->claim)))
                         return ERR_PTR(-ENXIO);
         } else {
@@ -1784,6 +1784,18 @@ void nd_region_create_blk_seed(struct nd_region *nd_region)
                 nd_device_register(nd_region->ns_seed);
 }
 
+void nd_region_create_dax_seed(struct nd_region *nd_region)
+{
+        WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
+        nd_region->dax_seed = nd_dax_create(nd_region);
+        /*
+         * Seed creation failures are not fatal, provisioning is simply
+         * disabled until memory becomes available
+         */
+        if (!nd_region->dax_seed)
+                dev_err(&nd_region->dev, "failed to create dax namespace\n");
+}
+
 void nd_region_create_pfn_seed(struct nd_region *nd_region)
 {
         WARN_ON(!is_nvdimm_bus_locked(&nd_region->dev));
diff --git a/drivers/nvdimm/nd-core.h b/drivers/nvdimm/nd-core.h
index 1d1500f3d8b5..cb65308c0329 100644
--- a/drivers/nvdimm/nd-core.h
+++ b/drivers/nvdimm/nd-core.h
@@ -54,6 +54,7 @@ struct nd_region;
 void nd_region_create_blk_seed(struct nd_region *nd_region);
 void nd_region_create_btt_seed(struct nd_region *nd_region);
 void nd_region_create_pfn_seed(struct nd_region *nd_region);
+void nd_region_create_dax_seed(struct nd_region *nd_region);
 void nd_region_disable(struct nvdimm_bus *nvdimm_bus, struct device *dev);
 int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 875c524fafb0..46910b8f32b1 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -13,6 +13,7 @@
 #ifndef __ND_H__
 #define __ND_H__
 #include <linux/libnvdimm.h>
+#include <linux/badblocks.h>
 #include <linux/blkdev.h>
 #include <linux/device.h>
 #include <linux/mutex.h>
@@ -100,10 +101,12 @@ struct nd_region {
         struct ida ns_ida;
         struct ida btt_ida;
         struct ida pfn_ida;
+        struct ida dax_ida;
         unsigned long flags;
         struct device *ns_seed;
         struct device *btt_seed;
         struct device *pfn_seed;
+        struct device *dax_seed;
         u16 ndr_mappings;
         u64 ndr_size;
         u64 ndr_start;
@@ -160,6 +163,10 @@ struct nd_pfn {
         struct nd_namespace_common *ndns;
 };
 
+struct nd_dax {
+        struct nd_pfn nd_pfn;
+};
+
 enum nd_async_mode {
         ND_SYNC,
         ND_ASYNC,
@@ -197,11 +204,12 @@ struct nd_gen_sb {
 
 u64 nd_sb_checksum(struct nd_gen_sb *sb);
 #if IS_ENABLED(CONFIG_BTT)
-int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata);
+int nd_btt_probe(struct device *dev, struct nd_namespace_common *ndns);
 bool is_nd_btt(struct device *dev);
 struct device *nd_btt_create(struct nd_region *nd_region);
 #else
-static inline int nd_btt_probe(struct nd_namespace_common *ndns, void *drvdata)
+static inline int nd_btt_probe(struct device *dev,
+                struct nd_namespace_common *ndns)
 {
         return -ENODEV;
 }
@@ -219,12 +227,16 @@ static inline struct device *nd_btt_create(struct nd_region *nd_region)
 
 struct nd_pfn *to_nd_pfn(struct device *dev);
 #if IS_ENABLED(CONFIG_NVDIMM_PFN)
-int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata);
+int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns);
 bool is_nd_pfn(struct device *dev);
 struct device *nd_pfn_create(struct nd_region *nd_region);
+struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
+                struct nd_namespace_common *ndns);
 int nd_pfn_validate(struct nd_pfn *nd_pfn);
+extern struct attribute_group nd_pfn_attribute_group;
 #else
-static inline int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
+static inline int nd_pfn_probe(struct device *dev,
+                struct nd_namespace_common *ndns)
 {
         return -ENODEV;
 }
@@ -245,6 +257,22 @@ static inline int nd_pfn_validate(struct nd_pfn *nd_pfn)
 }
 #endif
 
+struct nd_dax *to_nd_dax(struct device *dev);
+#if IS_ENABLED(CONFIG_NVDIMM_DAX)
+bool is_nd_dax(struct device *dev);
+struct device *nd_dax_create(struct nd_region *nd_region);
+#else
+static inline bool is_nd_dax(struct device *dev)
+{
+        return false;
+}
+
+static inline struct device *nd_dax_create(struct nd_region *nd_region)
+{
+        return NULL;
+}
+#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);
@@ -263,11 +291,32 @@ struct resource *nvdimm_allocate_dpa(struct nvdimm_drvdata *ndd,
 resource_size_t nvdimm_namespace_capacity(struct nd_namespace_common *ndns);
 struct nd_namespace_common *nvdimm_namespace_common_probe(struct device *dev);
 int nvdimm_namespace_attach_btt(struct nd_namespace_common *ndns);
-int nvdimm_namespace_detach_btt(struct nd_namespace_common *ndns);
+int nvdimm_namespace_detach_btt(struct nd_btt *nd_btt);
 const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
                 char *name);
 void nvdimm_badblocks_populate(struct nd_region *nd_region,
                 struct badblocks *bb, const struct resource *res);
+#if IS_ENABLED(CONFIG_ND_CLAIM)
+struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
+                struct resource *res, struct vmem_altmap *altmap);
+int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio);
+void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio);
+#else
+static inline struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
+                struct resource *res, struct vmem_altmap *altmap)
+{
+        return ERR_PTR(-ENXIO);
+}
+static inline int devm_nsio_enable(struct device *dev,
+                struct nd_namespace_io *nsio)
+{
+        return -ENXIO;
+}
+static inline void devm_nsio_disable(struct device *dev,
+                struct nd_namespace_io *nsio)
+{
+}
+#endif
 int nd_blk_region_init(struct nd_region *nd_region);
 void __nd_iostat_start(struct bio *bio, unsigned long *start);
 static inline bool nd_iostat_start(struct bio *bio, unsigned long *start)
@@ -281,6 +330,19 @@ static inline bool nd_iostat_start(struct bio *bio, unsigned long *start)
         return true;
 }
 void nd_iostat_end(struct bio *bio, unsigned long start);
+static inline bool is_bad_pmem(struct badblocks *bb, sector_t sector,
+                unsigned int len)
+{
+        if (bb->count) {
+                sector_t first_bad;
+                int num_bad;
+
+                return !!badblocks_check(bb, sector, len / 512, &first_bad,
+                                &num_bad);
+        }
+
+        return false;
+}
 resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk);
 const u8 *nd_dev_to_uuid(struct device *dev);
 bool pmem_should_map_pages(struct device *dev);
diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h
index 8e343a3ca873..9d2704c83fa7 100644
--- a/drivers/nvdimm/pfn.h
+++ b/drivers/nvdimm/pfn.h
@@ -33,7 +33,9 @@ struct nd_pfn_sb {
         /* minor-version-1 additions for section alignment */
         __le32 start_pad;
         __le32 end_trunc;
-        u8 padding[4004];
+        /* minor-version-2 record the base alignment of the mapping */
+        __le32 align;
+        u8 padding[4000];
         __le64 checksum;
 };
 
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index e071e214feba..2248056d29e7 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2013-2015 Intel Corporation. All rights reserved.
+ * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -10,6 +10,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  */
+#include <linux/memremap.h>
 #include <linux/blkdev.h>
 #include <linux/device.h>
 #include <linux/genhd.h>
@@ -53,10 +54,29 @@ struct nd_pfn *to_nd_pfn(struct device *dev)
 }
 EXPORT_SYMBOL(to_nd_pfn);
 
+static struct nd_pfn *to_nd_pfn_safe(struct device *dev)
+{
+        /*
+         * pfn device attributes are re-used by dax device instances, so we
+         * need to be careful to correct device-to-nd_pfn conversion.
+         */
+        if (is_nd_pfn(dev))
+                return to_nd_pfn(dev);
+
+        if (is_nd_dax(dev)) {
+                struct nd_dax *nd_dax = to_nd_dax(dev);
+
+                return &nd_dax->nd_pfn;
+        }
+
+        WARN_ON(1);
+        return NULL;
+}
+
 static ssize_t mode_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 
         switch (nd_pfn->mode) {
         case PFN_MODE_RAM:
@@ -71,7 +91,7 @@ static ssize_t mode_show(struct device *dev,
 static ssize_t mode_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t len)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc = 0;
 
         device_lock(dev);
@@ -105,7 +125,7 @@ static DEVICE_ATTR_RW(mode);
 static ssize_t align_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 
         return sprintf(buf, "%lx\n", nd_pfn->align);
 }
@@ -133,7 +153,7 @@ static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
 static ssize_t align_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t len)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         device_lock(dev);
@@ -151,7 +171,7 @@ static DEVICE_ATTR_RW(align);
 static ssize_t uuid_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
 
         if (nd_pfn->uuid)
                 return sprintf(buf, "%pUb\n", nd_pfn->uuid);
@@ -161,7 +181,7 @@ static ssize_t uuid_show(struct device *dev,
 static ssize_t uuid_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t len)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         device_lock(dev);
@@ -177,7 +197,7 @@ static DEVICE_ATTR_RW(uuid);
 static ssize_t namespace_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         nvdimm_bus_lock(dev);
@@ -190,7 +210,7 @@ static ssize_t namespace_show(struct device *dev,
 static ssize_t namespace_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t len)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         device_lock(dev);
@@ -208,7 +228,7 @@ static DEVICE_ATTR_RW(namespace);
 static ssize_t resource_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         device_lock(dev);
@@ -234,7 +254,7 @@ static DEVICE_ATTR_RO(resource);
 static ssize_t size_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
-        struct nd_pfn *nd_pfn = to_nd_pfn(dev);
+        struct nd_pfn *nd_pfn = to_nd_pfn_safe(dev);
         ssize_t rc;
 
         device_lock(dev);
@@ -269,7 +289,7 @@ static struct attribute *nd_pfn_attributes[] = {
         NULL,
 };
 
-static struct attribute_group nd_pfn_attribute_group = {
+struct attribute_group nd_pfn_attribute_group = {
         .attrs = nd_pfn_attributes,
 };
 
@@ -280,16 +300,32 @@ static const struct attribute_group *nd_pfn_attribute_groups[] = {
         NULL,
 };
 
-static struct device *__nd_pfn_create(struct nd_region *nd_region,
+struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
                 struct nd_namespace_common *ndns)
 {
-        struct nd_pfn *nd_pfn;
-        struct device *dev;
+        struct device *dev = &nd_pfn->dev;
 
-        /* we can only create pages for contiguous ranged of pmem */
-        if (!is_nd_pmem(&nd_region->dev))
+        if (!nd_pfn)
                 return NULL;
 
+        nd_pfn->mode = PFN_MODE_NONE;
+        nd_pfn->align = HPAGE_SIZE;
+        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));
+                put_device(dev);
+                return NULL;
+        }
+        return dev;
+}
+
+static struct nd_pfn *nd_pfn_alloc(struct nd_region *nd_region)
+{
+        struct nd_pfn *nd_pfn;
+        struct device *dev;
+
         nd_pfn = kzalloc(sizeof(*nd_pfn), GFP_KERNEL);
         if (!nd_pfn)
                 return NULL;
@@ -300,29 +336,27 @@ static struct device *__nd_pfn_create(struct nd_region *nd_region,
                 return NULL;
         }
 
-        nd_pfn->mode = PFN_MODE_NONE;
-        nd_pfn->align = HPAGE_SIZE;
         dev = &nd_pfn->dev;
         dev_set_name(dev, "pfn%d.%d", nd_region->id, nd_pfn->id);
-        dev->parent = &nd_region->dev;
-        dev->type = &nd_pfn_device_type;
         dev->groups = nd_pfn_attribute_groups;
-        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));
-                put_device(dev);
-                return NULL;
-        }
-        return dev;
+        dev->type = &nd_pfn_device_type;
+        dev->parent = &nd_region->dev;
+
+        return nd_pfn;
 }
 
 struct device *nd_pfn_create(struct nd_region *nd_region)
 {
-        struct device *dev = __nd_pfn_create(nd_region, NULL);
+        struct nd_pfn *nd_pfn;
+        struct device *dev;
+
+        if (!is_nd_pmem(&nd_region->dev))
+                return NULL;
 
-        if (dev)
-                __nd_device_register(dev);
+        nd_pfn = nd_pfn_alloc(nd_region);
+        dev = nd_pfn_devinit(nd_pfn, NULL);
+
+        __nd_device_register(dev);
         return dev;
 }
 
@@ -360,6 +394,9 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                 pfn_sb->end_trunc = 0;
         }
 
+        if (__le16_to_cpu(pfn_sb->version_minor) < 2)
+                pfn_sb->align = 0;
+
         switch (le32_to_cpu(pfn_sb->mode)) {
         case PFN_MODE_RAM:
         case PFN_MODE_PMEM:
@@ -399,7 +436,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
                 return -EBUSY;
         }
 
-        nd_pfn->align = 1UL << ilog2(offset);
+        nd_pfn->align = le32_to_cpu(pfn_sb->align);
         if (!is_power_of_2(offset) || offset < PAGE_SIZE) {
                 dev_err(&nd_pfn->dev, "bad offset: %#llx dax disabled\n",
                                 offset);
@@ -410,11 +447,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
 }
 EXPORT_SYMBOL(nd_pfn_validate);
 
-int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
+int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 {
         int rc;
-        struct device *dev;
         struct nd_pfn *nd_pfn;
+        struct device *pfn_dev;
         struct nd_pfn_sb *pfn_sb;
         struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
 
@@ -422,25 +459,213 @@ int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
                 return -ENODEV;
 
         nvdimm_bus_lock(&ndns->dev);
-        dev = __nd_pfn_create(nd_region, ndns);
+        nd_pfn = nd_pfn_alloc(nd_region);
+        pfn_dev = nd_pfn_devinit(nd_pfn, ndns);
         nvdimm_bus_unlock(&ndns->dev);
-        if (!dev)
+        if (!pfn_dev)
                 return -ENOMEM;
-        dev_set_drvdata(dev, drvdata);
-        pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
-        nd_pfn = to_nd_pfn(dev);
+        pfn_sb = devm_kzalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
+        nd_pfn = to_nd_pfn(pfn_dev);
         nd_pfn->pfn_sb = pfn_sb;
         rc = nd_pfn_validate(nd_pfn);
-        nd_pfn->pfn_sb = NULL;
-        kfree(pfn_sb);
-        dev_dbg(&ndns->dev, "%s: pfn: %s\n", __func__,
-                        rc == 0 ? dev_name(dev) : "<none>");
+        dev_dbg(dev, "%s: pfn: %s\n", __func__,
+                        rc == 0 ? dev_name(pfn_dev) : "<none>");
         if (rc < 0) {
-                __nd_detach_ndns(dev, &nd_pfn->ndns);
-                put_device(dev);
+                __nd_detach_ndns(pfn_dev, &nd_pfn->ndns);
+                put_device(pfn_dev);
         } else
-                __nd_device_register(&nd_pfn->dev);
+                __nd_device_register(pfn_dev);
 
         return rc;
 }
 EXPORT_SYMBOL(nd_pfn_probe);
+
+/*
+ * We hotplug memory at section granularity, pad the reserved area from
+ * the previous section base to the namespace base address.
+ */
+static unsigned long init_altmap_base(resource_size_t base)
+{
+        unsigned long base_pfn = PHYS_PFN(base);
+
+        return PFN_SECTION_ALIGN_DOWN(base_pfn);
+}
+
+static unsigned long init_altmap_reserve(resource_size_t base)
+{
+        unsigned long reserve = PHYS_PFN(SZ_8K);
+        unsigned long base_pfn = PHYS_PFN(base);
+
+        reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
+        return reserve;
+}
+
+static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
+                struct resource *res, struct vmem_altmap *altmap)
+{
+        struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
+        u64 offset = le64_to_cpu(pfn_sb->dataoff);
+        u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
+        u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
+        struct nd_namespace_common *ndns = nd_pfn->ndns;
+        struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+        resource_size_t base = nsio->res.start + start_pad;
+        struct vmem_altmap __altmap = {
+                .base_pfn = init_altmap_base(base),
+                .reserve = init_altmap_reserve(base),
+        };
+
+        memcpy(res, &nsio->res, sizeof(*res));
+        res->start += start_pad;
+        res->end -= end_trunc;
+
+        nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
+        if (nd_pfn->mode == PFN_MODE_RAM) {
+                if (offset < SZ_8K)
+                        return ERR_PTR(-EINVAL);
+                nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
+                altmap = NULL;
+        } else if (nd_pfn->mode == PFN_MODE_PMEM) {
+                nd_pfn->npfns = (resource_size(res) - offset) / PAGE_SIZE;
+                if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
+                        dev_info(&nd_pfn->dev,
+                                        "number of pfns truncated from %lld to %ld\n",
+                                        le64_to_cpu(nd_pfn->pfn_sb->npfns),
+                                        nd_pfn->npfns);
+                memcpy(altmap, &__altmap, sizeof(*altmap));
+                altmap->free = PHYS_PFN(offset - SZ_8K);
+                altmap->alloc = 0;
+        } else
+                return ERR_PTR(-ENXIO);
+
+        return altmap;
+}
+
+static int nd_pfn_init(struct nd_pfn *nd_pfn)
+{
+        u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
+        struct nd_namespace_common *ndns = nd_pfn->ndns;
+        u32 start_pad = 0, end_trunc = 0;
+        resource_size_t start, size;
+        struct nd_namespace_io *nsio;
+        struct nd_region *nd_region;
+        struct nd_pfn_sb *pfn_sb;
+        unsigned long npfns;
+        phys_addr_t offset;
+        u64 checksum;
+        int rc;
+
+        pfn_sb = devm_kzalloc(&nd_pfn->dev, sizeof(*pfn_sb), GFP_KERNEL);
+        if (!pfn_sb)
+                return -ENOMEM;
+
+        nd_pfn->pfn_sb = pfn_sb;
+        rc = nd_pfn_validate(nd_pfn);
+        if (rc != -ENODEV)
+                return rc;
+
+        /* no info block, do init */;
+        nd_region = to_nd_region(nd_pfn->dev.parent);
+        if (nd_region->ro) {
+                dev_info(&nd_pfn->dev,
+                                "%s is read-only, unable to init metadata\n",
+                                dev_name(&nd_region->dev));
+                return -ENXIO;
+        }
+
+        memset(pfn_sb, 0, sizeof(*pfn_sb));
+
+        /*
+         * Check if pmem collides with 'System RAM' when section aligned and
+         * trim it accordingly
+         */
+        nsio = to_nd_namespace_io(&ndns->dev);
+        start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
+        size = resource_size(&nsio->res);
+        if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
+                                IORES_DESC_NONE) == REGION_MIXED) {
+                start = nsio->res.start;
+                start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
+        }
+
+        start = nsio->res.start;
+        size = PHYS_SECTION_ALIGN_UP(start + size) - start;
+        if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
+                                IORES_DESC_NONE) == REGION_MIXED) {
+                size = resource_size(&nsio->res);
+                end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
+        }
+
+        if (start_pad + end_trunc)
+                dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
+                                dev_name(&ndns->dev), start_pad + end_trunc);
+
+        /*
+         * Note, we use 64 here for the standard size of struct page,
+         * debugging options may cause it to be larger in which case the
+         * implementation will limit the pfns advertised through
+         * ->direct_access() to those that are included in the memmap.
+         */
+        start += start_pad;
+        size = resource_size(&nsio->res);
+        npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K;
+        if (nd_pfn->mode == PFN_MODE_PMEM) {
+                unsigned long memmap_size;
+
+                /*
+                 * vmemmap_populate_hugepages() allocates the memmap array in
+                 * HPAGE_SIZE chunks.
+                 */
+                memmap_size = ALIGN(64 * npfns, HPAGE_SIZE);
+                offset = ALIGN(start + SZ_8K + memmap_size + dax_label_reserve,
+                                nd_pfn->align) - start;
+        } else if (nd_pfn->mode == PFN_MODE_RAM)
+                offset = ALIGN(start + SZ_8K + dax_label_reserve,
+                                nd_pfn->align) - start;
+        else
+                return -ENXIO;
+
+        if (offset + start_pad + end_trunc >= size) {
+                dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
+                                dev_name(&ndns->dev));
+                return -ENXIO;
+        }
+
+        npfns = (size - offset - start_pad - end_trunc) / SZ_4K;
+        pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
+        pfn_sb->dataoff = cpu_to_le64(offset);
+        pfn_sb->npfns = cpu_to_le64(npfns);
+        memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
+        memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
+        memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
+        pfn_sb->version_major = cpu_to_le16(1);
+        pfn_sb->version_minor = cpu_to_le16(2);
+        pfn_sb->start_pad = cpu_to_le32(start_pad);
+        pfn_sb->end_trunc = cpu_to_le32(end_trunc);
+        pfn_sb->align = cpu_to_le32(nd_pfn->align);
+        checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
+        pfn_sb->checksum = cpu_to_le64(checksum);
+
+        return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
+}
+
+/*
+ * Determine the effective resource range and vmem_altmap from an nd_pfn
+ * instance.
+ */
+struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
+                struct resource *res, struct vmem_altmap *altmap)
+{
+        int rc;
+
+        if (!nd_pfn->uuid || !nd_pfn->ndns)
+                return ERR_PTR(-ENODEV);
+
+        rc = nd_pfn_init(nd_pfn);
+        if (rc)
+                return ERR_PTR(rc);
+
+        /* we need a valid pfn_sb before we can init a vmem_altmap */
+        return __nvdimm_setup_pfn(nd_pfn, res, altmap);
+}
+EXPORT_SYMBOL_GPL(nvdimm_setup_pfn);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 92f536596b24..d9a0dbc2d023 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -33,10 +33,6 @@
 #include "nd.h"
 
 struct pmem_device {
-        struct request_queue    *pmem_queue;
-        struct gendisk          *pmem_disk;
-        struct nd_namespace_common *ndns;
-
         /* One contiguous memory region per device */
         phys_addr_t             phys_addr;
         /* when non-zero this device is hosting a 'pfn' instance */
@@ -50,23 +46,10 @@ struct pmem_device {
         struct badblocks        bb;
 };
 
-static bool is_bad_pmem(struct badblocks *bb, sector_t sector, unsigned int len)
-{
-        if (bb->count) {
-                sector_t first_bad;
-                int num_bad;
-
-                return !!badblocks_check(bb, sector, len / 512, &first_bad,
-                                &num_bad);
-        }
-
-        return false;
-}
-
 static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset,
                 unsigned int len)
 {
-        struct device *dev = disk_to_dev(pmem->pmem_disk);
+        struct device *dev = pmem->bb.dev;
         sector_t sector;
         long cleared;
 
@@ -136,8 +119,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
         unsigned long start;
         struct bio_vec bvec;
         struct bvec_iter iter;
-        struct block_device *bdev = bio->bi_bdev;
-        struct pmem_device *pmem = bdev->bd_disk->private_data;
+        struct pmem_device *pmem = q->queuedata;
 
         do_acct = nd_iostat_start(bio, &start);
         bio_for_each_segment(bvec, bio, iter) {
@@ -162,7 +144,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
 static int pmem_rw_page(struct block_device *bdev, sector_t sector,
                        struct page *page, int rw)
 {
-        struct pmem_device *pmem = bdev->bd_disk->private_data;
+        struct pmem_device *pmem = bdev->bd_queue->queuedata;
         int rc;
 
         rc = pmem_do_bvec(pmem, page, PAGE_SIZE, 0, rw, sector);
@@ -184,7 +166,7 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 static long pmem_direct_access(struct block_device *bdev, sector_t sector,
                       void __pmem **kaddr, pfn_t *pfn)
 {
-        struct pmem_device *pmem = bdev->bd_disk->private_data;
+        struct pmem_device *pmem = bdev->bd_queue->queuedata;
         resource_size_t offset = sector * 512 + pmem->data_offset;
 
         *kaddr = pmem->virt_addr + offset;
@@ -200,104 +182,119 @@ static const struct block_device_operations pmem_fops = {
         .revalidate_disk =      nvdimm_revalidate_disk,
 };
 
-static struct pmem_device *pmem_alloc(struct device *dev,
-                struct resource *res, int id)
+static void pmem_release_queue(void *q)
+{
+        blk_cleanup_queue(q);
+}
+
+void pmem_release_disk(void *disk)
 {
+        del_gendisk(disk);
+        put_disk(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 vmem_altmap __altmap, *altmap = NULL;
+        struct resource *res = &nsio->res;
+        struct nd_pfn *nd_pfn = NULL;
+        int nid = dev_to_node(dev);
+        struct nd_pfn_sb *pfn_sb;
         struct pmem_device *pmem;
+        struct resource pfn_res;
         struct request_queue *q;
+        struct 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);
 
         pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
         if (!pmem)
-                return ERR_PTR(-ENOMEM);
+                return -ENOMEM;
 
+        dev_set_drvdata(dev, pmem);
         pmem->phys_addr = res->start;
         pmem->size = resource_size(res);
         if (!arch_has_wmb_pmem())
                 dev_warn(dev, "unable to guarantee persistence of writes\n");
 
-        if (!devm_request_mem_region(dev, pmem->phys_addr, pmem->size,
-                        dev_name(dev))) {
-                dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n",
-                                &pmem->phys_addr, pmem->size);
-                return ERR_PTR(-EBUSY);
+        if (!devm_request_mem_region(dev, res->start, resource_size(res),
+                                dev_name(dev))) {
+                dev_warn(dev, "could not reserve region %pR\n", res);
+                return -EBUSY;
         }
 
         q = blk_alloc_queue_node(GFP_KERNEL, dev_to_node(dev));
         if (!q)
-                return ERR_PTR(-ENOMEM);
+                return -ENOMEM;
 
         pmem->pfn_flags = PFN_DEV;
-        if (pmem_should_map_pages(dev)) {
-                pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, res,
+        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
-                pmem->virt_addr = (void __pmem *) devm_memremap(dev,
-                                pmem->phys_addr, pmem->size,
-                                ARCH_MEMREMAP_PMEM);
+                addr = devm_memremap(dev, pmem->phys_addr,
+                                pmem->size, ARCH_MEMREMAP_PMEM);
 
-        if (IS_ERR(pmem->virt_addr)) {
+        /*
+         * At release time the queue must be dead before
+         * devm_memremap_pages is unwound
+         */
+        if (devm_add_action(dev, pmem_release_queue, q)) {
                 blk_cleanup_queue(q);
-                return (void __force *) pmem->virt_addr;
+                return -ENOMEM;
         }
 
-        pmem->pmem_queue = q;
-        return pmem;
-}
-
-static void pmem_detach_disk(struct pmem_device *pmem)
-{
-        if (!pmem->pmem_disk)
-                return;
-
-        del_gendisk(pmem->pmem_disk);
-        put_disk(pmem->pmem_disk);
-        blk_cleanup_queue(pmem->pmem_queue);
-}
+        if (IS_ERR(addr))
+                return PTR_ERR(addr);
+        pmem->virt_addr = (void __pmem *) addr;
 
-static int pmem_attach_disk(struct device *dev,
-                struct nd_namespace_common *ndns, struct pmem_device *pmem)
-{
-        struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
-        int nid = dev_to_node(dev);
-        struct resource bb_res;
-        struct gendisk *disk;
-
-        blk_queue_make_request(pmem->pmem_queue, pmem_make_request);
-        blk_queue_physical_block_size(pmem->pmem_queue, PAGE_SIZE);
-        blk_queue_max_hw_sectors(pmem->pmem_queue, UINT_MAX);
-        blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY);
-        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, pmem->pmem_queue);
+        blk_queue_make_request(q, pmem_make_request);
+        blk_queue_physical_block_size(q, PAGE_SIZE);
+        blk_queue_max_hw_sectors(q, UINT_MAX);
+        blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
+        queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
+        q->queuedata = pmem;
 
         disk = alloc_disk_node(0, nid);
-        if (!disk) {
-                blk_cleanup_queue(pmem->pmem_queue);
+        if (!disk)
+                return -ENOMEM;
+        if (devm_add_action(dev, pmem_release_disk, disk)) {
+                put_disk(disk);
                 return -ENOMEM;
         }
 
         disk->fops              = &pmem_fops;
-        disk->private_data      = pmem;
-        disk->queue             = pmem->pmem_queue;
+        disk->queue             = q;
         disk->flags             = GENHD_FL_EXT_DEVT;
         nvdimm_namespace_disk_name(ndns, disk->disk_name);
         disk->driverfs_dev = dev;
         set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
                         / 512);
-        pmem->pmem_disk = disk;
-        devm_exit_badblocks(dev, &pmem->bb);
         if (devm_init_badblocks(dev, &pmem->bb))
                 return -ENOMEM;
-        bb_res.start = nsio->res.start + pmem->data_offset;
-        bb_res.end = nsio->res.end;
-        if (is_nd_pfn(dev)) {
-                struct nd_pfn *nd_pfn = to_nd_pfn(dev);
-                struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
-
-                bb_res.start += __le32_to_cpu(pfn_sb->start_pad);
-                bb_res.end -= __le32_to_cpu(pfn_sb->end_trunc);
-        }
-        nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb,
-                        &bb_res);
+        nvdimm_badblocks_populate(to_nd_region(dev->parent), &pmem->bb, res);
         disk->bb = &pmem->bb;
         add_disk(disk);
         revalidate_disk(disk);
@@ -305,346 +302,67 @@ static int pmem_attach_disk(struct device *dev,
         return 0;
 }
 
-static int pmem_rw_bytes(struct nd_namespace_common *ndns,
-                resource_size_t offset, void *buf, size_t size, int rw)
-{
-        struct pmem_device *pmem = dev_get_drvdata(ndns->claim);
-
-        if (unlikely(offset + size > pmem->size)) {
-                dev_WARN_ONCE(&ndns->dev, 1, "request out of range\n");
-                return -EFAULT;
-        }
-
-        if (rw == READ) {
-                unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
-
-                if (unlikely(is_bad_pmem(&pmem->bb, offset / 512, sz_align)))
-                        return -EIO;
-                return memcpy_from_pmem(buf, pmem->virt_addr + offset, size);
-        } else {
-                memcpy_to_pmem(pmem->virt_addr + offset, buf, size);
-                wmb_pmem();
-        }
-
-        return 0;
-}
-
-static int nd_pfn_init(struct nd_pfn *nd_pfn)
-{
-        struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
-        struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
-        struct nd_namespace_common *ndns = nd_pfn->ndns;
-        u32 start_pad = 0, end_trunc = 0;
-        resource_size_t start, size;
-        struct nd_namespace_io *nsio;
-        struct nd_region *nd_region;
-        unsigned long npfns;
-        phys_addr_t offset;
-        u64 checksum;
-        int rc;
-
-        if (!pfn_sb)
-                return -ENOMEM;
-
-        nd_pfn->pfn_sb = pfn_sb;
-        rc = nd_pfn_validate(nd_pfn);
-        if (rc == -ENODEV)
-                /* no info block, do init */;
-        else
-                return rc;
-
-        nd_region = to_nd_region(nd_pfn->dev.parent);
-        if (nd_region->ro) {
-                dev_info(&nd_pfn->dev,
-                                "%s is read-only, unable to init metadata\n",
-                                dev_name(&nd_region->dev));
-                goto err;
-        }
-
-        memset(pfn_sb, 0, sizeof(*pfn_sb));
-
-        /*
-         * Check if pmem collides with 'System RAM' when section aligned and
-         * trim it accordingly
-         */
-        nsio = to_nd_namespace_io(&ndns->dev);
-        start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
-        size = resource_size(&nsio->res);
-        if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
-                                IORES_DESC_NONE) == REGION_MIXED) {
-
-                start = nsio->res.start;
-                start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
-        }
-
-        start = nsio->res.start;
-        size = PHYS_SECTION_ALIGN_UP(start + size) - start;
-        if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
-                                IORES_DESC_NONE) == REGION_MIXED) {
-                size = resource_size(&nsio->res);
-                end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
-        }
-
-        if (start_pad + end_trunc)
-                dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
-                                dev_name(&ndns->dev), start_pad + end_trunc);
-
-        /*
-         * Note, we use 64 here for the standard size of struct page,
-         * debugging options may cause it to be larger in which case the
-         * implementation will limit the pfns advertised through
-         * ->direct_access() to those that are included in the memmap.
-         */
-        start += start_pad;
-        npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
-        if (nd_pfn->mode == PFN_MODE_PMEM) {
-                unsigned long memmap_size;
-
-                /*
-                 * vmemmap_populate_hugepages() allocates the memmap array in
-                 * PMD_SIZE chunks.
-                 */
-                memmap_size = ALIGN(64 * npfns, PMD_SIZE);
-                offset = ALIGN(start + SZ_8K + memmap_size, nd_pfn->align)
-                        - start;
-        } else if (nd_pfn->mode == PFN_MODE_RAM)
-                offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
-        else
-                goto err;
-
-        if (offset + start_pad + end_trunc >= pmem->size) {
-                dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
-                                dev_name(&ndns->dev));
-                goto err;
-        }
-
-        npfns = (pmem->size - offset - start_pad - end_trunc) / SZ_4K;
-        pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
-        pfn_sb->dataoff = cpu_to_le64(offset);
-        pfn_sb->npfns = cpu_to_le64(npfns);
-        memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
-        memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
-        memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
-        pfn_sb->version_major = cpu_to_le16(1);
-        pfn_sb->version_minor = cpu_to_le16(1);
-        pfn_sb->start_pad = cpu_to_le32(start_pad);
-        pfn_sb->end_trunc = cpu_to_le32(end_trunc);
-        checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
-        pfn_sb->checksum = cpu_to_le64(checksum);
-
-        rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
-        if (rc)
-                goto err;
-
-        return 0;
- err:
-        nd_pfn->pfn_sb = NULL;
-        kfree(pfn_sb);
-        return -ENXIO;
-}
-
-static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
-{
-        struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
-        struct pmem_device *pmem;
-
-        /* free pmem disk */
-        pmem = dev_get_drvdata(&nd_pfn->dev);
-        pmem_detach_disk(pmem);
-
-        /* release nd_pfn resources */
-        kfree(nd_pfn->pfn_sb);
-        nd_pfn->pfn_sb = NULL;
-
-        return 0;
-}
-
-/*
- * We hotplug memory at section granularity, pad the reserved area from
- * the previous section base to the namespace base address.
- */
-static unsigned long init_altmap_base(resource_size_t base)
-{
-        unsigned long base_pfn = PHYS_PFN(base);
-
-        return PFN_SECTION_ALIGN_DOWN(base_pfn);
-}
-
-static unsigned long init_altmap_reserve(resource_size_t base)
-{
-        unsigned long reserve = PHYS_PFN(SZ_8K);
-        unsigned long base_pfn = PHYS_PFN(base);
-
-        reserve += base_pfn - PFN_SECTION_ALIGN_DOWN(base_pfn);
-        return reserve;
-}
-
-static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
-{
-        int rc;
-        struct resource res;
-        struct request_queue *q;
-        struct pmem_device *pmem;
-        struct vmem_altmap *altmap;
-        struct device *dev = &nd_pfn->dev;
-        struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
-        struct nd_namespace_common *ndns = nd_pfn->ndns;
-        u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
-        u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
-        struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
-        resource_size_t base = nsio->res.start + start_pad;
-        struct vmem_altmap __altmap = {
-                .base_pfn = init_altmap_base(base),
-                .reserve = init_altmap_reserve(base),
-        };
-
-        pmem = dev_get_drvdata(dev);
-        pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
-        pmem->pfn_pad = start_pad + end_trunc;
-        nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
-        if (nd_pfn->mode == PFN_MODE_RAM) {
-                if (pmem->data_offset < SZ_8K)
-                        return -EINVAL;
-                nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
-                altmap = NULL;
-        } else if (nd_pfn->mode == PFN_MODE_PMEM) {
-                nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
-                        / PAGE_SIZE;
-                if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
-                        dev_info(&nd_pfn->dev,
-                                        "number of pfns truncated from %lld to %ld\n",
-                                        le64_to_cpu(nd_pfn->pfn_sb->npfns),
-                                        nd_pfn->npfns);
-                altmap = & __altmap;
-                altmap->free = PHYS_PFN(pmem->data_offset - SZ_8K);
-                altmap->alloc = 0;
-        } else {
-                rc = -ENXIO;
-                goto err;
-        }
-
-        /* establish pfn range for lookup, and switch to direct map */
-        q = pmem->pmem_queue;
-        memcpy(&res, &nsio->res, sizeof(res));
-        res.start += start_pad;
-        res.end -= end_trunc;
-        devm_memunmap(dev, (void __force *) pmem->virt_addr);
-        pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
-                        &q->q_usage_counter, altmap);
-        pmem->pfn_flags |= PFN_MAP;
-        if (IS_ERR(pmem->virt_addr)) {
-                rc = PTR_ERR(pmem->virt_addr);
-                goto err;
-        }
-
-        /* attach pmem disk in "pfn-mode" */
-        rc = pmem_attach_disk(dev, ndns, pmem);
-        if (rc)
-                goto err;
-
-        return rc;
- err:
-        nvdimm_namespace_detach_pfn(ndns);
-        return rc;
-
-}
-
-static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
-{
-        struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
-        int rc;
-
-        if (!nd_pfn->uuid || !nd_pfn->ndns)
-                return -ENODEV;
-
-        rc = nd_pfn_init(nd_pfn);
-        if (rc)
-                return rc;
-        /* we need a valid pfn_sb before we can init a vmem_altmap */
-        return __nvdimm_namespace_attach_pfn(nd_pfn);
-}
-
 static int nd_pmem_probe(struct device *dev)
 {
-        struct nd_region *nd_region = to_nd_region(dev->parent);
         struct nd_namespace_common *ndns;
-        struct nd_namespace_io *nsio;
-        struct pmem_device *pmem;
 
         ndns = nvdimm_namespace_common_probe(dev);
         if (IS_ERR(ndns))
                 return PTR_ERR(ndns);
 
-        nsio = to_nd_namespace_io(&ndns->dev);
-        pmem = pmem_alloc(dev, &nsio->res, nd_region->id);
-        if (IS_ERR(pmem))
-                return PTR_ERR(pmem);
-
-        pmem->ndns = ndns;
-        dev_set_drvdata(dev, pmem);
-        ndns->rw_bytes = pmem_rw_bytes;
-        if (devm_init_badblocks(dev, &pmem->bb))
-                return -ENOMEM;
-        nvdimm_badblocks_populate(nd_region, &pmem->bb, &nsio->res);
+        if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev)))
+                return -ENXIO;
 
-        if (is_nd_btt(dev)) {
-                /* btt allocates its own request_queue */
-                blk_cleanup_queue(pmem->pmem_queue);
-                pmem->pmem_queue = NULL;
+        if (is_nd_btt(dev))
                 return nvdimm_namespace_attach_btt(ndns);
-        }
 
         if (is_nd_pfn(dev))
-                return nvdimm_namespace_attach_pfn(ndns);
+                return pmem_attach_disk(dev, ndns);
 
-        if (nd_btt_probe(ndns, pmem) == 0 || nd_pfn_probe(ndns, pmem) == 0) {
-                /*
-                 * We'll come back as either btt-pmem, or pfn-pmem, so
-                 * drop the queue allocation for now.
-                 */
-                blk_cleanup_queue(pmem->pmem_queue);
+        /* if we find a valid info-block we'll come back as that personality */
+        if (nd_btt_probe(dev, ndns) == 0 || nd_pfn_probe(dev, ndns) == 0)
                 return -ENXIO;
-        }
 
-        return pmem_attach_disk(dev, ndns, pmem);
+        /* ...otherwise we're just a raw pmem device */
+        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(pmem->ndns);
-        else if (is_nd_pfn(dev))
-                nvdimm_namespace_detach_pfn(pmem->ndns);
-        else
-                pmem_detach_disk(pmem);
-
+                nvdimm_namespace_detach_btt(to_nd_btt(dev));
         return 0;
 }
 
 static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
 {
-        struct pmem_device *pmem = dev_get_drvdata(dev);
-        struct nd_namespace_common *ndns = pmem->ndns;
         struct nd_region *nd_region = to_nd_region(dev->parent);
-        struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
-        struct resource res = {
-                .start = nsio->res.start + pmem->data_offset,
-                .end = nsio->res.end,
-        };
+        struct pmem_device *pmem = dev_get_drvdata(dev);
+        resource_size_t offset = 0, end_trunc = 0;
+        struct nd_namespace_common *ndns;
+        struct nd_namespace_io *nsio;
+        struct resource res;
 
         if (event != NVDIMM_REVALIDATE_POISON)
                 return;
 
-        if (is_nd_pfn(dev)) {
+        if (is_nd_btt(dev)) {
+                struct nd_btt *nd_btt = to_nd_btt(dev);
+
+                ndns = nd_btt->ndns;
+        } else if (is_nd_pfn(dev)) {
                 struct nd_pfn *nd_pfn = to_nd_pfn(dev);
                 struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 
-                res.start += __le32_to_cpu(pfn_sb->start_pad);
-                res.end -= __le32_to_cpu(pfn_sb->end_trunc);
-        }
+                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, &pmem->bb, &res);
 }
 
diff --git a/drivers/nvdimm/region.c b/drivers/nvdimm/region.c
index 4b7715e29cff..05a912359939 100644
--- a/drivers/nvdimm/region.c
+++ b/drivers/nvdimm/region.c
@@ -54,6 +54,7 @@ static int nd_region_probe(struct device *dev)
 
         nd_region->btt_seed = nd_btt_create(nd_region);
         nd_region->pfn_seed = nd_pfn_create(nd_region);
+        nd_region->dax_seed = nd_dax_create(nd_region);
         if (err == 0)
                 return 0;
 
@@ -86,6 +87,7 @@ static int nd_region_remove(struct device *dev)
         nd_region->ns_seed = NULL;
         nd_region->btt_seed = NULL;
         nd_region->pfn_seed = NULL;
+        nd_region->dax_seed = NULL;
         dev_set_drvdata(dev, NULL);
         nvdimm_bus_unlock(dev);
 
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 139bf71ca549..9e1b054e0e61 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -306,6 +306,23 @@ static ssize_t pfn_seed_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(pfn_seed);
 
+static ssize_t dax_seed_show(struct device *dev,
+                struct device_attribute *attr, char *buf)
+{
+        struct nd_region *nd_region = to_nd_region(dev);
+        ssize_t rc;
+
+        nvdimm_bus_lock(dev);
+        if (nd_region->dax_seed)
+                rc = sprintf(buf, "%s\n", dev_name(nd_region->dax_seed));
+        else
+                rc = sprintf(buf, "\n");
+        nvdimm_bus_unlock(dev);
+
+        return rc;
+}
+static DEVICE_ATTR_RO(dax_seed);
+
 static ssize_t read_only_show(struct device *dev,
                 struct device_attribute *attr, char *buf)
 {
@@ -335,6 +352,7 @@ static struct attribute *nd_region_attributes[] = {
         &dev_attr_mappings.attr,
         &dev_attr_btt_seed.attr,
         &dev_attr_pfn_seed.attr,
+        &dev_attr_dax_seed.attr,
         &dev_attr_read_only.attr,
         &dev_attr_set_cookie.attr,
         &dev_attr_available_size.attr,
@@ -353,6 +371,9 @@ static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n)
         if (!is_nd_pmem(dev) && a == &dev_attr_pfn_seed.attr)
                 return 0;
 
+        if (!is_nd_pmem(dev) && a == &dev_attr_dax_seed.attr)
+                return 0;
+
         if (a != &dev_attr_set_cookie.attr
                         && a != &dev_attr_available_size.attr)
                 return a->mode;
@@ -441,6 +462,13 @@ static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
                         nd_region_create_pfn_seed(nd_region);
                 nvdimm_bus_unlock(dev);
         }
+        if (is_nd_dax(dev) && probe) {
+                nd_region = to_nd_region(dev->parent);
+                nvdimm_bus_lock(dev);
+                if (nd_region->dax_seed == dev)
+                        nd_region_create_dax_seed(nd_region);
+                nvdimm_bus_unlock(dev);
+        }
 }
 
 void nd_region_probe_success(struct nvdimm_bus *nvdimm_bus, struct device *dev)
@@ -718,6 +746,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
         ida_init(&nd_region->ns_ida);
         ida_init(&nd_region->btt_ida);
         ida_init(&nd_region->pfn_ida);
+        ida_init(&nd_region->dax_ida);
         dev = &nd_region->dev;
         dev_set_name(dev, "region%d", nd_region->id);
         dev->parent = &nvdimm_bus->dev;