4 files changed, 61 insertions, 14 deletions

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 8493a2559daa..a8b6949a8778 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -185,8 +185,12 @@ long nvdimm_clear_poison(struct device *dev, phys_addr_t phys,
 		return -ENXIO;
 
 	nd_desc = nvdimm_bus->nd_desc;
+	/*
+	 * if ndctl does not exist, it's PMEM_LEGACY and
+	 * we want to just pretend everything is handled.
+	 */
 	if (!nd_desc->ndctl)
-		return -ENXIO;
+		return len;
 
 	memset(&ars_cap, 0, sizeof(ars_cap));
 	ars_cap.address = phys;
diff --git a/drivers/nvdimm/core.c b/drivers/nvdimm/core.c
index 42e40db4651b..7ceba08774b6 100644
--- a/drivers/nvdimm/core.c
+++ b/drivers/nvdimm/core.c
@@ -99,8 +99,11 @@ static struct nvdimm_map *alloc_nvdimm_map(struct device *dev,
 	nvdimm_map->size = size;
 	kref_init(&nvdimm_map->kref);
 
-	if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev)))
+	if (!request_mem_region(offset, size, dev_name(&nvdimm_bus->dev))) {
+		dev_err(&nvdimm_bus->dev, "failed to request %pa + %zd for %s\n",
+				&offset, size, dev_name(dev));
 		goto err_request_region;
+	}
 
 	if (flags)
 		nvdimm_map->mem = memremap(offset, size, flags);
@@ -171,6 +174,9 @@ void *devm_nvdimm_memremap(struct device *dev, resource_size_t offset,
 		kref_get(&nvdimm_map->kref);
 	nvdimm_bus_unlock(dev);
 
+	if (!nvdimm_map)
+		return NULL;
+
 	if (devm_add_action_or_reset(dev, nvdimm_map_put, nvdimm_map))
 		return NULL;
 
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index f67c61f1a8a4..d3b2fca8deec 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -52,10 +52,28 @@ struct nvdimm_drvdata {
 struct nd_region_data {
 	int ns_count;
 	int ns_active;
-	unsigned int flush_mask;
-	void __iomem *flush_wpq[0][0];
+	unsigned int hints_shift;
+	void __iomem *flush_wpq[0];
 };
 
+static inline void __iomem *ndrd_get_flush_wpq(struct nd_region_data *ndrd,
+		int dimm, int hint)
+{
+	unsigned int num = 1 << ndrd->hints_shift;
+	unsigned int mask = num - 1;
+
+	return ndrd->flush_wpq[dimm * num + (hint & mask)];
+}
+
+static inline void ndrd_set_flush_wpq(struct nd_region_data *ndrd, int dimm,
+		int hint, void __iomem *flush)
+{
+	unsigned int num = 1 << ndrd->hints_shift;
+	unsigned int mask = num - 1;
+
+	ndrd->flush_wpq[dimm * num + (hint & mask)] = flush;
+}
+
 static inline struct nd_namespace_index *to_namespace_index(
 		struct nvdimm_drvdata *ndd, int i)
 {
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 4f74e009b135..6af5e629140c 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -38,7 +38,7 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
 
 	dev_dbg(dev, "%s: map %d flush address%s\n", nvdimm_name(nvdimm),
 			nvdimm->num_flush, nvdimm->num_flush == 1 ? "" : "es");
-	for (i = 0; i < nvdimm->num_flush; i++) {
+	for (i = 0; i < (1 << ndrd->hints_shift); i++) {
 		struct resource *res = &nvdimm->flush_wpq[i];
 		unsigned long pfn = PHYS_PFN(res->start);
 		void __iomem *flush_page;
@@ -54,14 +54,15 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
 
 		if (j < i)
 			flush_page = (void __iomem *) ((unsigned long)
-					ndrd->flush_wpq[dimm][j] & PAGE_MASK);
+					ndrd_get_flush_wpq(ndrd, dimm, j)
+					& PAGE_MASK);
 		else
 			flush_page = devm_nvdimm_ioremap(dev,
-					PHYS_PFN(pfn), PAGE_SIZE);
+					PFN_PHYS(pfn), PAGE_SIZE);
 		if (!flush_page)
 			return -ENXIO;
-		ndrd->flush_wpq[dimm][i] = flush_page
-			+ (res->start & ~PAGE_MASK);
+		ndrd_set_flush_wpq(ndrd, dimm, i, flush_page
+				+ (res->start & ~PAGE_MASK));
 	}
 
 	return 0;
@@ -69,7 +70,7 @@ static int nvdimm_map_flush(struct device *dev, struct nvdimm *nvdimm, int dimm,
 
 int nd_region_activate(struct nd_region *nd_region)
 {
-	int i, num_flush = 0;
+	int i, j, num_flush = 0;
 	struct nd_region_data *ndrd;
 	struct device *dev = &nd_region->dev;
 	size_t flush_data_size = sizeof(void *);
@@ -93,7 +94,10 @@ int nd_region_activate(struct nd_region *nd_region)
 		return -ENOMEM;
 	dev_set_drvdata(dev, ndrd);
 
-	ndrd->flush_mask = (1 << ilog2(num_flush)) - 1;
+	if (!num_flush)
+		return 0;
+
+	ndrd->hints_shift = ilog2(num_flush);
 	for (i = 0; i < nd_region->ndr_mappings; i++) {
 		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
 		struct nvdimm *nvdimm = nd_mapping->nvdimm;
@@ -103,6 +107,21 @@ int nd_region_activate(struct nd_region *nd_region)
 			return rc;
 	}
 
+	/*
+	 * Clear out entries that are duplicates. This should prevent the
+	 * extra flushings.
+	 */
+	for (i = 0; i < nd_region->ndr_mappings - 1; i++) {
+		/* ignore if NULL already */
+		if (!ndrd_get_flush_wpq(ndrd, i, 0))
+			continue;
+
+		for (j = i + 1; j < nd_region->ndr_mappings; j++)
+			if (ndrd_get_flush_wpq(ndrd, i, 0) ==
+			    ndrd_get_flush_wpq(ndrd, j, 0))
+				ndrd_set_flush_wpq(ndrd, j, 0, NULL);
+	}
+
 	return 0;
 }
 
@@ -924,8 +943,8 @@ void nvdimm_flush(struct nd_region *nd_region)
 	 */
 	wmb();
 	for (i = 0; i < nd_region->ndr_mappings; i++)
-		if (ndrd->flush_wpq[i][0])
-			writeq(1, ndrd->flush_wpq[i][idx & ndrd->flush_mask]);
+		if (ndrd_get_flush_wpq(ndrd, i, 0))
+			writeq(1, ndrd_get_flush_wpq(ndrd, i, idx));
 	wmb();
 }
 EXPORT_SYMBOL_GPL(nvdimm_flush);
@@ -949,7 +968,7 @@ int nvdimm_has_flush(struct nd_region *nd_region)
 
 	for (i = 0; i < nd_region->ndr_mappings; i++)
 		/* flush hints present, flushing required */
-		if (ndrd->flush_wpq[i][0])
+		if (ndrd_get_flush_wpq(ndrd, i, 0))
 			return 1;
 
 	/*