acpi/nfit, libnvdimm/security: Add security DSM overwrite support

Add support for the NVDIMM_FAMILY_INTEL "ovewrite" capability as
described by the Intel DSM spec v1.7. This will allow triggering of
overwrite on Intel NVDIMMs. The overwrite operation can take tens of
minutes. When the overwrite DSM is issued successfully, the NVDIMMs will
be unaccessible. The kernel will do backoff polling to detect when the
overwrite process is completed. According to the DSM spec v1.7, the 128G
NVDIMMs can take up to 15mins to perform overwrite and larger DIMMs will
take longer.

Given that overwrite puts the DIMM in an indeterminate state until it
completes introduce the NDD_SECURITY_OVERWRITE flag to prevent other
operations from executing when overwrite is happening. The
NDD_WORK_PENDING flag is added to denote that there is a device reference
on the nvdimm device for an async workqueue thread context.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 9a6cb7067dc7..d18885304020 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -38,6 +38,10 @@ enum {
 	NDD_UNARMED = 1,
 	/* locked memory devices should not be accessed */
 	NDD_LOCKED = 2,
+	/* memory under security wipes should not be accessed */
+	NDD_SECURITY_OVERWRITE = 3,
+	/*  tracking whether or not there is a pending device reference */
+	NDD_WORK_PENDING = 4,
 
 	/* need to set a limit somewhere, but yes, this is likely overkill */
 	ND_IOCTL_MAX_BUFLEN = SZ_4M,
@@ -182,6 +186,9 @@ struct nvdimm_security_ops {
 			const struct nvdimm_key_data *key_data);
 	int (*erase)(struct nvdimm *nvdimm,
 			const struct nvdimm_key_data *key_data);
+	int (*overwrite)(struct nvdimm *nvdimm,
+			const struct nvdimm_key_data *key_data);
+	int (*query_overwrite)(struct nvdimm *nvdimm);
 };
 
 void badrange_init(struct badrange *badrange);
@@ -219,6 +226,7 @@ static inline struct nvdimm *nvdimm_create(struct nvdimm_bus *nvdimm_bus,
 			cmd_mask, num_flush, flush_wpq, NULL, NULL);
 }
 
+int nvdimm_security_setup_events(struct nvdimm *nvdimm);
 const struct nd_cmd_desc *nd_cmd_dimm_desc(int cmd);
 const struct nd_cmd_desc *nd_cmd_bus_desc(int cmd);
 u32 nd_cmd_in_size(struct nvdimm *nvdimm, int cmd,
@@ -244,6 +252,7 @@ u64 nd_fletcher64(void *addr, size_t len, bool le);
 void nvdimm_flush(struct nd_region *nd_region);
 int nvdimm_has_flush(struct nd_region *nd_region);
 int nvdimm_has_cache(struct nd_region *nd_region);
+int nvdimm_in_overwrite(struct nvdimm *nvdimm);
 
 static inline int nvdimm_ctl(struct nvdimm *nvdimm, unsigned int cmd, void *buf,
 		unsigned int buf_len, int *cmd_rc)