libnvdimm: Stop using HPAGE_SIZE
Currently libnvdimm uses HPAGE_SIZE as the default alignment for DAX and
PFN devices. HPAGE_SIZE is the default hugetlbfs page size and when
hugetlbfs is disabled it defaults to PAGE_SIZE. Given DAX has more
in common with THP than hugetlbfs we should proably be using
HPAGE_PMD_SIZE, but this is undefined when THP is disabled so lets just
give it a new name.
The other usage of HPAGE_SIZE in libnvdimm is when determining how large
the altmap should be. For the reasons mentioned above it doesn't really
make sense to use HPAGE_SIZE here either. PMD_SIZE seems to be safe to
use in generic code and it happens to match the vmemmap allocation block
on x86 and Power. It's still a hack, but it's a slightly nicer hack.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 5fcb6f5..2ae9a00 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -290,7 +290,7 @@ 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 +638,12 @@ 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;