@@ -540,6 +540,7 @@ static struct vmem_altmap *__nvdimm_setup_pfn(struct nd_pfn *nd_pfn,
static int nd_pfn_init(struct nd_pfn *nd_pfn)
{
+ u32 dax_label_reserve = is_nd_dax(&nd_pfn->dev) ? SZ_128K : 0;
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = 0, end_trunc = 0;
resource_size_t start, size;
@@ -606,10 +607,11 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
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;
+ offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
+ nd_pfn->align) - start;
else if (nd_pfn->mode == PFN_MODE_RAM)
- offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
+ offset = ALIGN(start + SZ_8K + dax_label_reserve,
+ nd_pfn->align) - start;
else
return -ENXIO;
We may want to subdivide a device-dax range into multiple devices so that each can have separate permissions or naming. Reserve 128K of label space by default so we have the capability of making allocation decisions persistent. This reservation is not something we can add later since it would result in the default size of a device-dax range changing between kernel versions. Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/nvdimm/pfn_devs.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)