summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/nfit/core.c4
-rw-r--r--drivers/dax/bus.c2
-rw-r--r--drivers/dax/super.c19
-rw-r--r--drivers/md/dm-table.c24
-rw-r--r--drivers/md/dm.c5
-rw-r--r--drivers/md/dm.h5
-rw-r--r--drivers/nvdimm/Makefile1
-rw-r--r--drivers/nvdimm/claim.c6
-rw-r--r--drivers/nvdimm/namespace_devs.c8
-rw-r--r--drivers/nvdimm/nd.h1
-rw-r--r--drivers/nvdimm/nd_virtio.c125
-rw-r--r--drivers/nvdimm/pmem.c18
-rw-r--r--drivers/nvdimm/region_devs.c33
-rw-r--r--drivers/nvdimm/virtio_pmem.c122
-rw-r--r--drivers/nvdimm/virtio_pmem.h55
-rw-r--r--drivers/s390/block/dcssblk.c2
-rw-r--r--drivers/virtio/Kconfig11
17 files changed, 413 insertions, 28 deletions
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 23022cf20d26..c02fa27dd3f3 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2426,7 +2426,7 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
offset = to_interleave_offset(offset, mmio);
writeq(cmd, mmio->addr.base + offset);
- nvdimm_flush(nfit_blk->nd_region);
+ nvdimm_flush(nfit_blk->nd_region, NULL);
if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
readq(mmio->addr.base + offset);
@@ -2475,7 +2475,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
}
if (rw)
- nvdimm_flush(nfit_blk->nd_region);
+ nvdimm_flush(nfit_blk->nd_region, NULL);
rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0;
return rc;
diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 2109cfe80219..5f184e751c82 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -388,7 +388,7 @@ struct dev_dax *__devm_create_dev_dax(struct dax_region *dax_region, int id,
* No 'host' or dax_operations since there is no access to this
* device outside of mmap of the resulting character device.
*/
- dax_dev = alloc_dax(dev_dax, NULL, NULL);
+ dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
if (!dax_dev)
goto err;
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 4e5ae7e8b557..8ab12068eea3 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -195,6 +195,8 @@ enum dax_device_flags {
DAXDEV_ALIVE,
/* gate whether dax_flush() calls the low level flush routine */
DAXDEV_WRITE_CACHE,
+ /* flag to check if device supports synchronous flush */
+ DAXDEV_SYNC,
};
/**
@@ -372,6 +374,18 @@ bool dax_write_cache_enabled(struct dax_device *dax_dev)
}
EXPORT_SYMBOL_GPL(dax_write_cache_enabled);
+bool __dax_synchronous(struct dax_device *dax_dev)
+{
+ return test_bit(DAXDEV_SYNC, &dax_dev->flags);
+}
+EXPORT_SYMBOL_GPL(__dax_synchronous);
+
+void __set_dax_synchronous(struct dax_device *dax_dev)
+{
+ set_bit(DAXDEV_SYNC, &dax_dev->flags);
+}
+EXPORT_SYMBOL_GPL(__set_dax_synchronous);
+
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
@@ -526,7 +540,7 @@ static void dax_add_host(struct dax_device *dax_dev, const char *host)
}
struct dax_device *alloc_dax(void *private, const char *__host,
- const struct dax_operations *ops)
+ const struct dax_operations *ops, unsigned long flags)
{
struct dax_device *dax_dev;
const char *host;
@@ -549,6 +563,9 @@ struct dax_device *alloc_dax(void *private, const char *__host,
dax_add_host(dax_dev, host);
dax_dev->ops = ops;
dax_dev->private = private;
+ if (flags & DAXDEV_F_SYNC)
+ set_dax_synchronous(dax_dev);
+
return dax_dev;
err_dev:
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index ec8b27e20de3..caaee8032afe 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -881,7 +881,7 @@ void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
EXPORT_SYMBOL_GPL(dm_table_set_type);
/* validate the dax capability of the target device span */
-static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
int blocksize = *(int *) data;
@@ -890,7 +890,15 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
start, len);
}
-bool dm_table_supports_dax(struct dm_table *t, int blocksize)
+/* Check devices support synchronous DAX */
+static int device_synchronous(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
+{
+ return dax_synchronous(dev->dax_dev);
+}
+
+bool dm_table_supports_dax(struct dm_table *t,
+ iterate_devices_callout_fn iterate_fn, int *blocksize)
{
struct dm_target *ti;
unsigned i;
@@ -903,8 +911,7 @@ bool dm_table_supports_dax(struct dm_table *t, int blocksize)
return false;
if (!ti->type->iterate_devices ||
- !ti->type->iterate_devices(ti, device_supports_dax,
- &blocksize))
+ !ti->type->iterate_devices(ti, iterate_fn, blocksize))
return false;
}
@@ -940,6 +947,7 @@ static int dm_table_determine_type(struct dm_table *t)
struct dm_target *tgt;
struct list_head *devices = dm_table_get_devices(t);
enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
+ int page_size = PAGE_SIZE;
if (t->type != DM_TYPE_NONE) {
/* target already set the table's type */
@@ -984,7 +992,7 @@ static int dm_table_determine_type(struct dm_table *t)
verify_bio_based:
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
- if (dm_table_supports_dax(t, PAGE_SIZE) ||
+ if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
(list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
} else {
@@ -1883,6 +1891,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
bool wc = false, fua = false;
+ int page_size = PAGE_SIZE;
/*
* Copy table's limits to the DM device's request_queue
@@ -1910,8 +1919,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
}
blk_queue_write_cache(q, wc, fua);
- if (dm_table_supports_dax(t, PAGE_SIZE))
+ if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
blk_queue_flag_set(QUEUE_FLAG_DAX, q);
+ if (dm_table_supports_dax(t, device_synchronous, NULL))
+ set_dax_synchronous(t->md->dax_dev);
+ }
else
blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 61f1152b74e9..d0beef033e2f 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1117,7 +1117,7 @@ static bool dm_dax_supported(struct dax_device *dax_dev, struct block_device *bd
if (!map)
return false;
- ret = dm_table_supports_dax(map, blocksize);
+ ret = dm_table_supports_dax(map, device_supports_dax, &blocksize);
dm_put_live_table(md, srcu_idx);
@@ -1989,7 +1989,8 @@ static struct mapped_device *alloc_dev(int minor)
sprintf(md->disk->disk_name, "dm-%d", minor);
if (IS_ENABLED(CONFIG_DAX_DRIVER)) {
- md->dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops);
+ md->dax_dev = alloc_dax(md, md->disk->disk_name,
+ &dm_dax_ops, 0);
if (!md->dax_dev)
goto bad;
}
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 17e3db54404c..0475673337f3 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -72,7 +72,10 @@ bool dm_table_bio_based(struct dm_table *t);
bool dm_table_request_based(struct dm_table *t);
void dm_table_free_md_mempools(struct dm_table *t);
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
-bool dm_table_supports_dax(struct dm_table *t, int blocksize);
+bool dm_table_supports_dax(struct dm_table *t, iterate_devices_callout_fn fn,
+ int *blocksize);
+int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data);
void dm_lock_md_type(struct mapped_device *md);
void dm_unlock_md_type(struct mapped_device *md);
diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile
index 6f2a088afad6..cefe233e0b52 100644
--- a/drivers/nvdimm/Makefile
+++ b/drivers/nvdimm/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_ND_BTT) += nd_btt.o
obj-$(CONFIG_ND_BLK) += nd_blk.o
obj-$(CONFIG_X86_PMEM_LEGACY) += nd_e820.o
obj-$(CONFIG_OF_PMEM) += of_pmem.o
+obj-$(CONFIG_VIRTIO_PMEM) += virtio_pmem.o nd_virtio.o
nd_pmem-y := pmem.o
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index 26c1c7618891..2985ca949912 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -255,7 +255,7 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
unsigned int sz_align = ALIGN(size + (offset & (512 - 1)), 512);
sector_t sector = offset >> 9;
- int rc = 0;
+ int rc = 0, ret = 0;
if (unlikely(!size))
return 0;
@@ -293,7 +293,9 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns,
}
memcpy_flushcache(nsio->addr + offset, buf, size);
- nvdimm_flush(to_nd_region(ndns->dev.parent));
+ ret = nvdimm_flush(to_nd_region(ndns->dev.parent), NULL);
+ if (ret)
+ rc = ret;
return rc;
}
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index a434a5964cb9..2d8d7e554877 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1822,8 +1822,8 @@ static bool has_uuid_at_pos(struct nd_region *nd_region, u8 *uuid,
&& !guid_equal(&nd_set->type_guid,
&nd_label->type_guid)) {
dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
- nd_set->type_guid.b,
- nd_label->type_guid.b);
+ &nd_set->type_guid,
+ &nd_label->type_guid);
continue;
}
@@ -2227,8 +2227,8 @@ static struct device *create_namespace_blk(struct nd_region *nd_region,
if (namespace_label_has(ndd, type_guid)) {
if (!guid_equal(&nd_set->type_guid, &nd_label->type_guid)) {
dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
- nd_set->type_guid.b,
- nd_label->type_guid.b);
+ &nd_set->type_guid,
+ &nd_label->type_guid);
return ERR_PTR(-EAGAIN);
}
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index d24304c0e6d7..1b9955651379 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -155,6 +155,7 @@ struct nd_region {
struct badblocks bb;
struct nd_interleave_set *nd_set;
struct nd_percpu_lane __percpu *lane;
+ int (*flush)(struct nd_region *nd_region, struct bio *bio);
struct nd_mapping mapping[0];
};
diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c
new file mode 100644
index 000000000000..10351d5b49fa
--- /dev/null
+++ b/drivers/nvdimm/nd_virtio.c
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * virtio_pmem.c: Virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and provides a virtio based flushing
+ * interface.
+ */
+#include "virtio_pmem.h"
+#include "nd.h"
+
+ /* The interrupt handler */
+void virtio_pmem_host_ack(struct virtqueue *vq)
+{
+ struct virtio_pmem *vpmem = vq->vdev->priv;
+ struct virtio_pmem_request *req_data, *req_buf;
+ unsigned long flags;
+ unsigned int len;
+
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ while ((req_data = virtqueue_get_buf(vq, &len)) != NULL) {
+ req_data->done = true;
+ wake_up(&req_data->host_acked);
+
+ if (!list_empty(&vpmem->req_list)) {
+ req_buf = list_first_entry(&vpmem->req_list,
+ struct virtio_pmem_request, list);
+ req_buf->wq_buf_avail = true;
+ wake_up(&req_buf->wq_buf);
+ list_del(&req_buf->list);
+ }
+ }
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+}
+EXPORT_SYMBOL_GPL(virtio_pmem_host_ack);
+
+ /* The request submission function */
+static int virtio_pmem_flush(struct nd_region *nd_region)
+{
+ struct virtio_device *vdev = nd_region->provider_data;
+ struct virtio_pmem *vpmem = vdev->priv;
+ struct virtio_pmem_request *req_data;
+ struct scatterlist *sgs[2], sg, ret;
+ unsigned long flags;
+ int err, err1;
+
+ might_sleep();
+ req_data = kmalloc(sizeof(*req_data), GFP_KERNEL);
+ if (!req_data)
+ return -ENOMEM;
+
+ req_data->done = false;
+ init_waitqueue_head(&req_data->host_acked);
+ init_waitqueue_head(&req_data->wq_buf);
+ INIT_LIST_HEAD(&req_data->list);
+ req_data->req.type = cpu_to_le32(VIRTIO_PMEM_REQ_TYPE_FLUSH);
+ sg_init_one(&sg, &req_data->req, sizeof(req_data->req));
+ sgs[0] = &sg;
+ sg_init_one(&ret, &req_data->resp.ret, sizeof(req_data->resp));
+ sgs[1] = &ret;
+
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ /*
+ * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual
+ * queue does not have free descriptor. We add the request
+ * to req_list and wait for host_ack to wake us up when free
+ * slots are available.
+ */
+ while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data,
+ GFP_ATOMIC)) == -ENOSPC) {
+
+ dev_info(&vdev->dev, "failed to send command to virtio pmem device, no free slots in the virtqueue\n");
+ req_data->wq_buf_avail = false;
+ list_add_tail(&req_data->list, &vpmem->req_list);
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+
+ /* A host response results in "host_ack" getting called */
+ wait_event(req_data->wq_buf, req_data->wq_buf_avail);
+ spin_lock_irqsave(&vpmem->pmem_lock, flags);
+ }
+ err1 = virtqueue_kick(vpmem->req_vq);
+ spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
+ /*
+ * virtqueue_add_sgs failed with error different than -ENOSPC, we can't
+ * do anything about that.
+ */
+ if (err || !err1) {
+ dev_info(&vdev->dev, "failed to send command to virtio pmem device\n");
+ err = -EIO;
+ } else {
+ /* A host repsonse results in "host_ack" getting called */
+ wait_event(req_data->host_acked, req_data->done);
+ err = le32_to_cpu(req_data->resp.ret);
+ }
+
+ kfree(req_data);
+ return err;
+};
+
+/* The asynchronous flush callback function */
+int async_pmem_flush(struct nd_region *nd_region, struct bio *bio)
+{
+ /*
+ * Create child bio for asynchronous flush and chain with
+ * parent bio. Otherwise directly call nd_region flush.
+ */
+ if (bio && bio->bi_iter.bi_sector != -1) {
+ struct bio *child = bio_alloc(GFP_ATOMIC, 0);
+
+ if (!child)
+ return -ENOMEM;
+ bio_copy_dev(child, bio);
+ child->bi_opf = REQ_PREFLUSH;
+ child->bi_iter.bi_sector = -1;
+ bio_chain(child, bio);
+ submit_bio(child);
+ return 0;
+ }
+ if (virtio_pmem_flush(nd_region))
+ return -EIO;
+
+ return 0;
+};
+EXPORT_SYMBOL_GPL(async_pmem_flush);
+MODULE_LICENSE("GPL");
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index e7d8cc9f41e8..2bf3acd69613 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -184,6 +184,7 @@ static blk_status_t pmem_do_bvec(struct pmem_device *pmem, struct page *page,
static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
{
+ int ret = 0;
blk_status_t rc = 0;
bool do_acct;
unsigned long start;
@@ -193,7 +194,7 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
struct nd_region *nd_region = to_region(pmem);
if (bio->bi_opf & REQ_PREFLUSH)
- nvdimm_flush(nd_region);
+ ret = nvdimm_flush(nd_region, bio);
do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
@@ -208,7 +209,10 @@ static blk_qc_t pmem_make_request(struct request_queue *q, struct bio *bio)
nd_iostat_end(bio, start);
if (bio->bi_opf & REQ_FUA)
- nvdimm_flush(nd_region);
+ ret = nvdimm_flush(nd_region, bio);
+
+ if (ret)
+ bio->bi_status = errno_to_blk_status(ret);
bio_endio(bio);
return BLK_QC_T_NONE;
@@ -362,6 +366,7 @@ static int pmem_attach_disk(struct device *dev,
struct gendisk *disk;
void *addr;
int rc;
+ unsigned long flags = 0UL;
pmem = devm_kzalloc(dev, sizeof(*pmem), GFP_KERNEL);
if (!pmem)
@@ -457,14 +462,15 @@ static int pmem_attach_disk(struct device *dev,
nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res);
disk->bb = &pmem->bb;
- dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops);
+ if (is_nvdimm_sync(nd_region))
+ flags = DAXDEV_F_SYNC;
+ dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops, flags);
if (!dax_dev) {
put_disk(disk);
return -ENOMEM;
}
dax_write_cache(dax_dev, nvdimm_has_cache(nd_region));
pmem->dax_dev = dax_dev;
-
gendev = disk_to_dev(disk);
gendev->groups = pmem_attribute_groups;
@@ -522,14 +528,14 @@ static int nd_pmem_remove(struct device *dev)
sysfs_put(pmem->bb_state);
pmem->bb_state = NULL;
}
- nvdimm_flush(to_nd_region(dev->parent));
+ nvdimm_flush(to_nd_region(dev->parent), NULL);
return 0;
}
static void nd_pmem_shutdown(struct device *dev)
{
- nvdimm_flush(to_nd_region(dev->parent));
+ nvdimm_flush(to_nd_region(dev->parent), NULL);
}
static void nd_pmem_notify(struct device *dev, enum nvdimm_event event)
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 4fed9ce9c2fe..56f2227f192a 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -287,7 +287,9 @@ static ssize_t deep_flush_store(struct device *dev, struct device_attribute *att
return rc;
if (!flush)
return -EINVAL;
- nvdimm_flush(nd_region);
+ rc = nvdimm_flush(nd_region, NULL);
+ if (rc)
+ return rc;
return len;
}
@@ -1077,6 +1079,11 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
dev->of_node = ndr_desc->of_node;
nd_region->ndr_size = resource_size(ndr_desc->res);
nd_region->ndr_start = ndr_desc->res->start;
+ if (ndr_desc->flush)
+ nd_region->flush = ndr_desc->flush;
+ else
+ nd_region->flush = NULL;
+
nd_device_register(dev);
return nd_region;
@@ -1117,11 +1124,24 @@ struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
}
EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
+int nvdimm_flush(struct nd_region *nd_region, struct bio *bio)
+{
+ int rc = 0;
+
+ if (!nd_region->flush)
+ rc = generic_nvdimm_flush(nd_region);
+ else {
+ if (nd_region->flush(nd_region, bio))
+ rc = -EIO;
+ }
+
+ return rc;
+}
/**
* nvdimm_flush - flush any posted write queues between the cpu and pmem media
* @nd_region: blk or interleaved pmem region
*/
-void nvdimm_flush(struct nd_region *nd_region)
+int generic_nvdimm_flush(struct nd_region *nd_region)
{
struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
int i, idx;
@@ -1145,6 +1165,8 @@ void nvdimm_flush(struct nd_region *nd_region)
if (ndrd_get_flush_wpq(ndrd, i, 0))
writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
wmb();
+
+ return 0;
}
EXPORT_SYMBOL_GPL(nvdimm_flush);
@@ -1189,6 +1211,13 @@ int nvdimm_has_cache(struct nd_region *nd_region)
}
EXPORT_SYMBOL_GPL(nvdimm_has_cache);
+bool is_nvdimm_sync(struct nd_region *nd_region)
+{
+ return is_nd_pmem(&nd_region->dev) &&
+ !test_bit(ND_REGION_ASYNC, &nd_region->flags);
+}
+EXPORT_SYMBOL_GPL(is_nvdimm_sync);
+
struct conflict_context {
struct nd_region *nd_region;
resource_size_t start, size;
diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c
new file mode 100644
index 000000000000..5e3d07b47e0c
--- /dev/null
+++ b/drivers/nvdimm/virtio_pmem.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * virtio_pmem.c: Virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and registers the virtual pmem device
+ * with libnvdimm core.
+ */
+#include "virtio_pmem.h"
+#include "nd.h"
+
+static struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_PMEM, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+ /* Initialize virt queue */
+static int init_vq(struct virtio_pmem *vpmem)
+{
+ /* single vq */
+ vpmem->req_vq = virtio_find_single_vq(vpmem->vdev,
+ virtio_pmem_host_ack, "flush_queue");
+ if (IS_ERR(vpmem->req_vq))
+ return PTR_ERR(vpmem->req_vq);
+
+ spin_lock_init(&vpmem->pmem_lock);
+ INIT_LIST_HEAD(&vpmem->req_list);
+
+ return 0;
+};
+
+static int virtio_pmem_probe(struct virtio_device *vdev)
+{
+ struct nd_region_desc ndr_desc = {};
+ int nid = dev_to_node(&vdev->dev);
+ struct nd_region *nd_region;
+ struct virtio_pmem *vpmem;
+ struct resource res;
+ int err = 0;
+
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "%s failure: config access disabled\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ vpmem = devm_kzalloc(&vdev->dev, sizeof(*vpmem), GFP_KERNEL);
+ if (!vpmem) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
+ vpmem->vdev = vdev;
+ vdev->priv = vpmem;
+ err = init_vq(vpmem);
+ if (err) {
+ dev_err(&vdev->dev, "failed to initialize virtio pmem vq's\n");
+ goto out_err;
+ }
+
+ virtio_cread(vpmem->vdev, struct virtio_pmem_config,
+ start, &vpmem->start);
+ virtio_cread(vpmem->vdev, struct virtio_pmem_config,
+ size, &vpmem->size);
+
+ res.start = vpmem->start;
+ res.end = vpmem->start + vpmem->size - 1;
+ vpmem->nd_desc.provider_name = "virtio-pmem";
+ vpmem->nd_desc.module = THIS_MODULE;
+
+ vpmem->nvdimm_bus = nvdimm_bus_register(&vdev->dev,
+ &vpmem->nd_desc);
+ if (!vpmem->nvdimm_bus) {
+ dev_err(&vdev->dev, "failed to register device with nvdimm_bus\n");
+ err = -ENXIO;
+ goto out_vq;
+ }
+
+ dev_set_drvdata(&vdev->dev, vpmem->nvdimm_bus);
+
+ ndr_desc.res = &res;
+ ndr_desc.numa_node = nid;
+ ndr_desc.flush = async_pmem_flush;
+ set_bit(ND_REGION_PAGEMAP, &ndr_desc.flags);
+ set_bit(ND_REGION_ASYNC, &ndr_desc.flags);
+ nd_region = nvdimm_pmem_region_create(vpmem->nvdimm_bus, &ndr_desc);
+ if (!nd_region) {
+ dev_err(&vdev->dev, "failed to create nvdimm region\n");
+ err = -ENXIO;
+ goto out_nd;
+ }
+ nd_region->provider_data = dev_to_virtio(nd_region->dev.parent->parent);
+ return 0;
+out_nd:
+ nvdimm_bus_unregister(vpmem->nvdimm_bus);
+out_vq:
+ vdev->config->del_vqs(vdev);
+out_err:
+ return err;
+}
+
+static void virtio_pmem_remove(struct virtio_device *vdev)
+{
+ struct nvdimm_bus *nvdimm_bus = dev_get_drvdata(&vdev->dev);
+
+ nvdimm_bus_unregister(nvdimm_bus);
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+}
+
+static struct virtio_driver virtio_pmem_driver = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .probe = virtio_pmem_probe,
+ .remove = virtio_pmem_remove,
+};
+
+module_virtio_driver(virtio_pmem_driver);
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio pmem driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/nvdimm/virtio_pmem.h b/drivers/nvdimm/virtio_pmem.h
new file mode 100644
index 000000000000..0dddefe594c4
--- /dev/null
+++ b/drivers/nvdimm/virtio_pmem.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * virtio_pmem.h: virtio pmem Driver
+ *
+ * Discovers persistent memory range information
+ * from host and provides a virtio based flushing
+ * interface.
+ **/
+
+#ifndef _LINUX_VIRTIO_PMEM_H
+#define _LINUX_VIRTIO_PMEM_H
+
+#include <linux/module.h>
+#include <uapi/linux/virtio_pmem.h>
+#include <linux/libnvdimm.h>
+#include <linux/spinlock.h>
+
+struct virtio_pmem_request {
+ struct virtio_pmem_req req;
+ struct virtio_pmem_resp resp;
+
+ /* Wait queue to process deferred work after ack from host */
+ wait_queue_head_t host_acked;
+ bool done;
+
+ /* Wait queue to process deferred work after virt queue buffer avail */
+ wait_queue_head_t wq_buf;
+ bool wq_buf_avail;
+ struct list_head list;
+};
+
+struct virtio_pmem {
+ struct virtio_device *vdev;
+
+ /* Virtio pmem request queue */
+ struct virtqueue *req_vq;
+
+ /* nvdimm bus registers virtio pmem device */
+ struct nvdimm_bus *nvdimm_bus;
+ struct nvdimm_bus_descriptor nd_desc;
+
+ /* List to store deferred work if virtqueue is full */
+ struct list_head req_list;
+
+ /* Synchronize virtqueue data */
+ spinlock_t pmem_lock;
+
+ /* Memory region information */
+ __u64 start;
+ __u64 size;
+};
+
+void virtio_pmem_host_ack(struct virtqueue *vq);
+int async_pmem_flush(struct nd_region *nd_region, struct bio *bio);
+#endif
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index d04d4378ca50..63502ca537eb 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -679,7 +679,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
goto put_dev;
dev_info->dax_dev = alloc_dax(dev_info, dev_info->gd->disk_name,
- &dcssblk_dax_ops);
+ &dcssblk_dax_ops, DAXDEV_F_SYNC);
if (!dev_info->dax_dev) {
rc = -ENOMEM;
goto put_dev;
diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig
index 023fc3bc01c6..078615cf2afc 100644
--- a/drivers/virtio/Kconfig
+++ b/drivers/virtio/Kconfig
@@ -43,6 +43,17 @@ config VIRTIO_PCI_LEGACY
If unsure, say Y.
+config VIRTIO_PMEM
+ tristate "Support for virtio pmem driver"
+ depends on VIRTIO
+ depends on LIBNVDIMM
+ help
+ This driver provides access to virtio-pmem devices, storage devices
+ that are mapped into the physical address space - similar to NVDIMMs
+ - with a virtio-based flushing interface.
+
+ If unsure, say Y.
+
config VIRTIO_BALLOON
tristate "Virtio balloon driver"
depends on VIRTIO