[RFC PATCH 3/4] libnvdimm/namespace: Use direct-mapping page size to validate namespace size

[Aneesh Kumar K.V]

Architectures like ppc64 use different page size than PAGE_SIZE to map
direct-map address range. The kernel needs to make sure the namespace size is 
aligned
correctly for the direct-map page size.

Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
 drivers/nvdimm/namespace_devs.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index fcde9f2bf2ea..83c70631a86f 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -975,7 +975,8 @@ static ssize_t __size_store(struct device *dev, unsigned 
long long val)
        struct nd_mapping *nd_mapping;
        struct nvdimm_drvdata *ndd;
        struct nd_label_id label_id;
-       u32 flags = 0, remainder;
+       unsigned long map_size;
+       u32 flags = 0;
        int rc, i, id = -1;
        u8 *uuid = NULL;
 
@@ -1006,10 +1007,9 @@ static ssize_t __size_store(struct device *dev, unsigned 
long long val)
                return -ENXIO;
        }
 
-       div_u64_rem(val, PAGE_SIZE * nd_region->ndr_mappings, &remainder);
-       if (remainder) {
-               dev_dbg(dev, "%llu is not %ldK aligned\n", val,
-                               (PAGE_SIZE * nd_region->ndr_mappings) / SZ_1K);
+       map_size = arch_validate_namespace_size(nd_region->ndr_mappings, val);
+       if (map_size) {
+               dev_err(dev, "%llu is not %ldK aligned\n", val, map_size / 
SZ_1K);
                return -EINVAL;
        }
 
-- 
2.21.0