tools/testing/cxl: Add "Set Passphrase" opcode support

Add support to emulate a CXL mem device supporting the "Set Passphrase"
operation. The operation supports setting of either a user or a master
passphrase.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983611314.2734609.12996309794483934484.stgit@djiang5-desk3.ch.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/cxl/test/mem.c

@@ -65,9 +65,16 @@ static struct {
 	},
 };
 
+#define PASS_TRY_LIMIT 3
+
 struct cxl_mockmem_data {
 	void *lsa;
 	u32 security_state;
+	u8 user_pass[NVDIMM_PASSPHRASE_LEN];
+	u8 master_pass[NVDIMM_PASSPHRASE_LEN];
+	int user_limit;
+	int master_limit;
+
 };
 
 static int mock_gsl(struct cxl_mbox_cmd *cmd)
@@ -158,6 +165,84 @@ static int mock_get_security_state(struct cxl_dev_state *cxlds,
 	return 0;
 }
 
+static void master_plimit_check(struct cxl_mockmem_data *mdata)
+{
+	if (mdata->master_limit == PASS_TRY_LIMIT)
+		return;
+	mdata->master_limit++;
+	if (mdata->master_limit == PASS_TRY_LIMIT)
+		mdata->security_state |= CXL_PMEM_SEC_STATE_MASTER_PLIMIT;
+}
+
+static void user_plimit_check(struct cxl_mockmem_data *mdata)
+{
+	if (mdata->user_limit == PASS_TRY_LIMIT)
+		return;
+	mdata->user_limit++;
+	if (mdata->user_limit == PASS_TRY_LIMIT)
+		mdata->security_state |= CXL_PMEM_SEC_STATE_USER_PLIMIT;
+}
+
+static int mock_set_passphrase(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mockmem_data *mdata = dev_get_drvdata(cxlds->dev);
+	struct cxl_set_pass *set_pass;
+
+	if (cmd->size_in != sizeof(*set_pass))
+		return -EINVAL;
+
+	if (cmd->size_out != 0)
+		return -EINVAL;
+
+	if (mdata->security_state & CXL_PMEM_SEC_STATE_FROZEN) {
+		cmd->return_code = CXL_MBOX_CMD_RC_SECURITY;
+		return -ENXIO;
+	}
+
+	set_pass = cmd->payload_in;
+	switch (set_pass->type) {
+	case CXL_PMEM_SEC_PASS_MASTER:
+		if (mdata->security_state & CXL_PMEM_SEC_STATE_MASTER_PLIMIT) {
+			cmd->return_code = CXL_MBOX_CMD_RC_SECURITY;
+			return -ENXIO;
+		}
+		/*
+		 * CXL spec rev3.0 8.2.9.8.6.2, The master pasphrase shall only be set in
+		 * the security disabled state when the user passphrase is not set.
+		 */
+		if (mdata->security_state & CXL_PMEM_SEC_STATE_USER_PASS_SET) {
+			cmd->return_code = CXL_MBOX_CMD_RC_SECURITY;
+			return -ENXIO;
+		}
+		if (memcmp(mdata->master_pass, set_pass->old_pass, NVDIMM_PASSPHRASE_LEN)) {
+			master_plimit_check(mdata);
+			cmd->return_code = CXL_MBOX_CMD_RC_PASSPHRASE;
+			return -ENXIO;
+		}
+		memcpy(mdata->master_pass, set_pass->new_pass, NVDIMM_PASSPHRASE_LEN);
+		mdata->security_state |= CXL_PMEM_SEC_STATE_MASTER_PASS_SET;
+		return 0;
+
+	case CXL_PMEM_SEC_PASS_USER:
+		if (mdata->security_state & CXL_PMEM_SEC_STATE_USER_PLIMIT) {
+			cmd->return_code = CXL_MBOX_CMD_RC_SECURITY;
+			return -ENXIO;
+		}
+		if (memcmp(mdata->user_pass, set_pass->old_pass, NVDIMM_PASSPHRASE_LEN)) {
+			user_plimit_check(mdata);
+			cmd->return_code = CXL_MBOX_CMD_RC_PASSPHRASE;
+			return -ENXIO;
+		}
+		memcpy(mdata->user_pass, set_pass->new_pass, NVDIMM_PASSPHRASE_LEN);
+		mdata->security_state |= CXL_PMEM_SEC_STATE_USER_PASS_SET;
+		return 0;
+
+	default:
+		cmd->return_code = CXL_MBOX_CMD_RC_INPUT;
+	}
+	return -EINVAL;
+}
+
 static int mock_get_lsa(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
 	struct cxl_mbox_get_lsa *get_lsa = cmd->payload_in;
@@ -256,6 +341,9 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
 	case CXL_MBOX_OP_GET_SECURITY_STATE:
 		rc = mock_get_security_state(cxlds, cmd);
 		break;
+	case CXL_MBOX_OP_SET_PASSPHRASE:
+		rc = mock_set_passphrase(cxlds, cmd);
+		break;
 	default:
 		break;
 	}