libnvdimm, pmem: direct map legacy pmem by default
The expectation is that the legacy / non-standard pmem discovery method
(e820 type-12) will only ever be used to describe small quantities of
persistent memory. Larger capacities will be described via the ACPI
NFIT. When "allocate struct page from pmem" support is added this default
policy can be overridden by assigning a legacy pmem namespace to a pfn
device, however this would be only be necessary if a platform used the
legacy mechanism to define a very large range.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 75e3af0..3f021dc 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -31,6 +31,9 @@
ND_CMD_ARS_STATUS_MAX = SZ_4K,
ND_MAX_MAPPINGS = 32,
+ /* region flag indicating to direct-map persistent memory by default */
+ ND_REGION_PAGEMAP = 0,
+
/* mark newly adjusted resources as requiring a label update */
DPA_RESOURCE_ADJUSTED = 1 << 0,
};
@@ -91,6 +94,7 @@
void *provider_data;
int num_lanes;
int numa_node;
+ unsigned long flags;
};
struct nvdimm_bus;