1 files changed, 33 insertions, 20 deletions

diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 5fcb6f5b22a2..9576c444f0ab 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -111,24 +111,27 @@ static ssize_t align_show(struct device *dev,
 	return sprintf(buf, "%ld\n", nd_pfn->align);
 }
 
-static ssize_t __align_store(struct nd_pfn *nd_pfn, const char *buf)
+static const unsigned long *nd_pfn_supported_alignments(void)
 {
-	unsigned long val;
-	int rc;
-
-	rc = kstrtoul(buf, 0, &val);
-	if (rc)
-		return rc;
-
-	if (!is_power_of_2(val) || val < PAGE_SIZE || val > SZ_1G)
-		return -EINVAL;
+	/*
+	 * This needs to be a non-static variable because the *_SIZE
+	 * macros aren't always constants.
+	 */
+	const unsigned long supported_alignments[] = {
+		PAGE_SIZE,
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+		HPAGE_PMD_SIZE,
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+		HPAGE_PUD_SIZE,
+#endif
+#endif
+		0,
+	};
+	static unsigned long data[ARRAY_SIZE(supported_alignments)];
 
-	if (nd_pfn->dev.driver)
-		return -EBUSY;
-	else
-		nd_pfn->align = val;
+	memcpy(data, supported_alignments, sizeof(data));
 
-	return 0;
+	return data;
 }
 
 static ssize_t align_store(struct device *dev,
@@ -139,7 +142,8 @@ static ssize_t align_store(struct device *dev,
 
 	device_lock(dev);
 	nvdimm_bus_lock(dev);
-	rc = __align_store(nd_pfn, buf);
+	rc = nd_size_select_store(dev, buf, &nd_pfn->align,
+			nd_pfn_supported_alignments());
 	dev_dbg(dev, "%s: result: %zd wrote: %s%s", __func__,
 			rc, buf, buf[len - 1] == '\n' ? "" : "\n");
 	nvdimm_bus_unlock(dev);
@@ -260,6 +264,13 @@ static ssize_t size_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(size);
 
+static ssize_t supported_alignments_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return nd_size_select_show(0, nd_pfn_supported_alignments(), buf);
+}
+static DEVICE_ATTR_RO(supported_alignments);
+
 static struct attribute *nd_pfn_attributes[] = {
 	&dev_attr_mode.attr,
 	&dev_attr_namespace.attr,
@@ -267,6 +278,7 @@ static struct attribute *nd_pfn_attributes[] = {
 	&dev_attr_align.attr,
 	&dev_attr_resource.attr,
 	&dev_attr_size.attr,
+	&dev_attr_supported_alignments.attr,
 	NULL,
 };
 
@@ -290,7 +302,7 @@ struct device *nd_pfn_devinit(struct nd_pfn *nd_pfn,
 		return NULL;
 
 	nd_pfn->mode = PFN_MODE_NONE;
-	nd_pfn->align = HPAGE_SIZE;
+	nd_pfn->align = PFN_DEFAULT_ALIGNMENT;
 	dev = &nd_pfn->dev;
 	device_initialize(&nd_pfn->dev);
 	if (ndns && !__nd_attach_ndns(&nd_pfn->dev, ndns, &nd_pfn->ndns)) {
@@ -638,11 +650,12 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
 			/ PAGE_SIZE);
 	if (nd_pfn->mode == PFN_MODE_PMEM) {
 		/*
-		 * vmemmap_populate_hugepages() allocates the memmap array in
-		 * HPAGE_SIZE chunks.
+		 * The altmap should be padded out to the block size used
+		 * when populating the vmemmap. This *should* be equal to
+		 * PMD_SIZE for most architectures.
 		 */
 		offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
-				max(nd_pfn->align, HPAGE_SIZE)) - start;
+				max(nd_pfn->align, PMD_SIZE)) - start;
 	} else if (nd_pfn->mode == PFN_MODE_RAM)
 		offset = ALIGN(start + SZ_8K + dax_label_reserve,
 				nd_pfn->align) - start;