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>

2 files changed, 95 insertions, 0 deletions

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 41c261ab793e..ab57a3fe4511 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2045,6 +2045,11 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
 		if (!nvdimm)
 			continue;
 
+		rc = nvdimm_security_setup_events(nvdimm);
+		if (rc < 0)
+			dev_warn(acpi_desc->dev,
+				"security event setup failed: %d\n", rc);
+
 		nfit_kernfs = sysfs_get_dirent(nvdimm_kobj(nvdimm)->sd, "nfit");
 		if (nfit_kernfs)
 			nfit_mem->flags_attr = sysfs_get_dirent(nfit_kernfs,
diff --git a/drivers/acpi/nfit/intel.c b/drivers/acpi/nfit/intel.c
index e0e04b730b4f..82e805d4458a 100644
--- a/drivers/acpi/nfit/intel.c
+++ b/drivers/acpi/nfit/intel.c
@@ -28,6 +28,14 @@ static enum nvdimm_security_state intel_security_state(struct nvdimm *nvdimm)
 	if (!test_bit(NVDIMM_INTEL_GET_SECURITY_STATE, &nfit_mem->dsm_mask))
 		return -ENXIO;
 
+	/*
+	 * Short circuit the state retrieval while we are doing overwrite.
+	 * The DSM spec states that the security state is indeterminate
+	 * until the overwrite DSM completes.
+	 */
+	if (nvdimm_in_overwrite(nvdimm))
+		return NVDIMM_SECURITY_OVERWRITE;
+
 	rc = nvdimm_ctl(nvdimm, ND_CMD_CALL, &nd_cmd, sizeof(nd_cmd), NULL);
 	if (rc < 0)
 		return rc;
@@ -249,6 +257,86 @@ static int intel_security_erase(struct nvdimm *nvdimm,
 	return 0;
 }
 
+static int intel_security_query_overwrite(struct nvdimm *nvdimm)
+{
+	int rc;
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+	struct {
+		struct nd_cmd_pkg pkg;
+		struct nd_intel_query_overwrite cmd;
+	} nd_cmd = {
+		.pkg = {
+			.nd_command = NVDIMM_INTEL_QUERY_OVERWRITE,
+			.nd_family = NVDIMM_FAMILY_INTEL,
+			.nd_size_out = ND_INTEL_STATUS_SIZE,
+			.nd_fw_size = ND_INTEL_STATUS_SIZE,
+		},
+	};
+
+	if (!test_bit(NVDIMM_INTEL_QUERY_OVERWRITE, &nfit_mem->dsm_mask))
+		return -ENOTTY;
+
+	rc = nvdimm_ctl(nvdimm, ND_CMD_CALL, &nd_cmd, sizeof(nd_cmd), NULL);
+	if (rc < 0)
+		return rc;
+
+	switch (nd_cmd.cmd.status) {
+	case 0:
+		break;
+	case ND_INTEL_STATUS_OQUERY_INPROGRESS:
+		return -EBUSY;
+	default:
+		return -ENXIO;
+	}
+
+	/* flush all cache before we make the nvdimms available */
+	nvdimm_invalidate_cache();
+	return 0;
+}
+
+static int intel_security_overwrite(struct nvdimm *nvdimm,
+		const struct nvdimm_key_data *nkey)
+{
+	int rc;
+	struct nfit_mem *nfit_mem = nvdimm_provider_data(nvdimm);
+	struct {
+		struct nd_cmd_pkg pkg;
+		struct nd_intel_overwrite cmd;
+	} nd_cmd = {
+		.pkg = {
+			.nd_command = NVDIMM_INTEL_OVERWRITE,
+			.nd_family = NVDIMM_FAMILY_INTEL,
+			.nd_size_in = ND_INTEL_PASSPHRASE_SIZE,
+			.nd_size_out = ND_INTEL_STATUS_SIZE,
+			.nd_fw_size = ND_INTEL_STATUS_SIZE,
+		},
+	};
+
+	if (!test_bit(NVDIMM_INTEL_OVERWRITE, &nfit_mem->dsm_mask))
+		return -ENOTTY;
+
+	/* flush all cache before we erase DIMM */
+	nvdimm_invalidate_cache();
+	if (nkey)
+		memcpy(nd_cmd.cmd.passphrase, nkey->data,
+				sizeof(nd_cmd.cmd.passphrase));
+	rc = nvdimm_ctl(nvdimm, ND_CMD_CALL, &nd_cmd, sizeof(nd_cmd), NULL);
+	if (rc < 0)
+		return rc;
+
+	switch (nd_cmd.cmd.status) {
+	case 0:
+		return 0;
+	case ND_INTEL_STATUS_OVERWRITE_UNSUPPORTED:
+		return -ENOTSUPP;
+	case ND_INTEL_STATUS_INVALID_PASS:
+		return -EINVAL;
+	case ND_INTEL_STATUS_INVALID_STATE:
+	default:
+		return -ENXIO;
+	}
+}
+
 /*
  * TODO: define a cross arch wbinvd equivalent when/if
  * NVDIMM_FAMILY_INTEL command support arrives on another arch.
@@ -273,6 +361,8 @@ static const struct nvdimm_security_ops __intel_security_ops = {
 #ifdef CONFIG_X86
 	.unlock = intel_security_unlock,
 	.erase = intel_security_erase,
+	.overwrite = intel_security_overwrite,
+	.query_overwrite = intel_security_query_overwrite,
 #endif
 };