[PATCH v2] libnvdimm, pmem, pfn: move pfn setup to the core

[Dan Williams]

Now that pmem internals have been disentangled from pfn setup, that code
can move to the core.  This is in preparation for adding another user of
the pfn-device capabilities.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Changes in v2:
* Cleaned up the -ENODEV checking in nd_pfn_init() (Johannes)

 drivers/nvdimm/nd.h       |    7 ++
 drivers/nvdimm/pfn_devs.c |  181 ++++++++++++++++++++++++++++++++++++++++++++
 drivers/nvdimm/pmem.c     |  184 ---------------------------------------------
 3 files changed, 188 insertions(+), 184 deletions(-)

diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 10e23fe49012..6c36509662e4 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -272,9 +272,16 @@ const char *nvdimm_namespace_disk_name(struct nd_namespace_common *ndns,
 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)
 {
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index f8fd379501bf..92468d30099e 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -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>
@@ -441,3 +442,183 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns)
 	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)
+{
+	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)
+		offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
+			- start;
+	else if (nd_pfn->mode == PFN_MODE_RAM)
+		offset = ALIGN(start + SZ_8K, 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(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);
+
+	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 904f904e2962..ccbb58699c8f 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -182,9 +182,6 @@ void pmem_release_disk(void *disk)
 	put_disk(disk);
 }
 
-static struct vmem_altmap *nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
-		struct resource *res, struct vmem_altmap *altmap);
-
 static int pmem_attach_disk(struct device *dev,
 		struct nd_namespace_common *ndns)
 {
@@ -296,187 +293,6 @@ static int pmem_attach_disk(struct device *dev,
 	return 0;
 }
 
-static int nd_pfn_init(struct nd_pfn *nd_pfn)
-{
-	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)
-		/* 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));
-		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)
-		offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
-			- start;
-	else if (nd_pfn->mode == PFN_MODE_RAM)
-		offset = ALIGN(start + SZ_8K, 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(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);
-
-	return nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
-}
-
-/*
- * 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;
-}
-
-/*
- * Determine the effective resource range and vmem_altmap from an nd_pfn
- * instance.
- */
-static 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);
-}
-
 static int nd_pmem_probe(struct device *dev)
 {
 	struct nd_namespace_common *ndns;