[PATCH 2/3] libnvdimm: nd_region flush callback support

Pankaj Gupta
2018-08-31T13:30:17Z

This patch adds functionality to perform flush from guest
to host over VIRTIO. We are registering a callback based
on 'nd_region' type. virtio_pmem driver requires this special
flush function. For rest of the region types we are registering
existing flush function. Report error returned by host fsync
failure to userspace.

Signed-off-by: Pankaj Gupta <pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
drivers/acpi/nfit/core.c | 7 +++++--
drivers/nvdimm/claim.c | 3 ++-
drivers/nvdimm/pmem.c | 12 ++++++++----
drivers/nvdimm/region_devs.c | 12 ++++++++++--
include/linux/libnvdimm.h | 4 +++-
5 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index b072cfc..cd63b69 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2216,6 +2216,7 @@ static void write_blk_ctl(struct nfit_blk *nfit_blk, unsigned int bw,
{
u64 cmd, offset;
struct nfit_blk_mmio *mmio = &nfit_blk->mmio[DCR];
+ struct nd_region *nd_region = nfit_blk->nd_region;

enum {
BCW_OFFSET_MASK = (1ULL << 48)-1,
@@ -2234,7 +2235,7 @@ 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);
+ nd_region->flush(nd_region);

if (nfit_blk->dimm_flags & NFIT_BLK_DCR_LATCH)
readq(mmio->addr.base + offset);
@@ -2245,6 +2246,7 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
unsigned int lane)
{
struct nfit_blk_mmio *mmio = &nfit_blk->mmio[BDW];
+ struct nd_region *nd_region = nfit_blk->nd_region;
unsigned int copied = 0;
u64 base_offset;
int rc;
@@ -2283,7 +2285,8 @@ static int acpi_nfit_blk_single_io(struct nfit_blk *nfit_blk,
}

if (rw)
- nvdimm_flush(nfit_blk->nd_region);
+ nd_region->flush(nd_region);
+

rc = read_blk_stat(nfit_blk, lane) ? -EIO : 0;
return rc;
diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c
index fb667bf..49dce9c 100644
--- a/drivers/nvdimm/claim.c
+++ b/drivers/nvdimm/claim.c
@@ -262,6 +262,7 @@ 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);
+ struct nd_region *nd_region = to_nd_region(ndns->dev.parent);
sector_t sector = offset >> 9;
int rc = 0;

@@ -301,7 +302,7 @@ 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));
+ nd_region->flush(nd_region);

return rc;
}
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 6071e29..ba57cfa 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -201,7 +201,8 @@ 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);
+ bio->bi_status = nd_region->flush(nd_region);
+

do_acct = nd_iostat_start(bio, &start);
bio_for_each_segment(bvec, bio, iter) {
@@ -216,7 +217,7 @@ 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);
+ bio->bi_status = nd_region->flush(nd_region);

bio_endio(bio);
return BLK_QC_T_NONE;
@@ -517,6 +518,7 @@ static int nd_pmem_probe(struct device *dev)
static int nd_pmem_remove(struct device *dev)
{
struct pmem_device *pmem = dev_get_drvdata(dev);
+ struct nd_region *nd_region = to_region(pmem);

if (is_nd_btt(dev))
nvdimm_namespace_detach_btt(to_nd_btt(dev));
@@ -528,14 +530,16 @@ static int nd_pmem_remove(struct device *dev)
sysfs_put(pmem->bb_state);
pmem->bb_state = NULL;
}
- nvdimm_flush(to_nd_region(dev->parent));
+ nd_region->flush(nd_region);

return 0;
}

static void nd_pmem_shutdown(struct device *dev)
{
- nvdimm_flush(to_nd_region(dev->parent));
+ struct nd_region *nd_region = to_nd_region(dev->parent);
+
+ nd_region->flush(nd_region);
}

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 fa37afc..a170a6b 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -290,7 +290,7 @@ static ssize_t deep_flush_store(struct device *dev, struct device_attribute *att
return rc;
if (!flush)
return -EINVAL;
- nvdimm_flush(nd_region);
+ nd_region->flush(nd_region);

return len;
}
@@ -1065,6 +1065,11 @@ 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 = nvdimm_flush;
+
nd_device_register(dev);

return nd_region;
@@ -1109,7 +1114,7 @@ EXPORT_SYMBOL_GPL(nvdimm_volatile_region_create);
* 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 nvdimm_flush(struct nd_region *nd_region)
{
struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
int i, idx;
@@ -1133,7 +1138,10 @@ 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);

/**
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 097072c..3af7177 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -115,6 +115,7 @@ struct nd_mapping_desc {
int position;
};

+struct nd_region;
struct nd_region_desc {
struct resource *res;
struct nd_mapping_desc *mapping;
@@ -126,6 +127,7 @@ struct nd_region_desc {
int numa_node;
unsigned long flags;
struct device_node *of_node;
+ int (*flush)(struct nd_region *nd_region);
};

struct device;
@@ -201,7 +203,7 @@ unsigned long nd_blk_memremap_flags(struct nd_blk_region *ndbr);
unsigned int nd_region_acquire_lane(struct nd_region *nd_region);
void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane);
u64 nd_fletcher64(void *addr, size_t len, bool le);
-void nvdimm_flush(struct nd_region *nd_region);
+int nvdimm_flush(struct nd_region *nd_region);
int nvdimm_has_flush(struct nd_region *nd_region);
int nvdimm_has_cache(struct nd_region *nd_region);

--
2.9.3