tools/testing/cxl: Set Shutdown State support

Add support to emulate the CXL Set Shutdown State operation.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20250220220235.276831-5-dave@stgolabs.net
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: Davidlohr Bueso

tools/testing/cxl/test/mem.c

@@ -65,6 +65,10 @@ static struct cxl_cel_entry mock_cel[] = {
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_HEALTH_INFO),
 		.effect = CXL_CMD_EFFECT_NONE,
 	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_SET_SHUTDOWN_STATE),
+		.effect = POLICY_CHANGE_IMMEDIATE,
+	},
 	{
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_POISON),
 		.effect = CXL_CMD_EFFECT_NONE,
@@ -161,6 +165,7 @@ struct cxl_mockmem_data {
 	u8 event_buf[SZ_4K];
 	u64 timestamp;
 	unsigned long sanitize_timeout;
+	u8 shutdown_state;
 };
 
 static struct mock_event_log *event_find_log(struct device *dev, int log_type)
@@ -1088,6 +1093,21 @@ static int mock_health_info(struct cxl_mbox_cmd *cmd)
 	return 0;
 }
 
+static int mock_set_shutdown_state(struct cxl_mockmem_data *mdata,
+				   struct cxl_mbox_cmd *cmd)
+{
+	struct cxl_mbox_set_shutdown_state_in *ss = cmd->payload_in;
+
+	if (cmd->size_in != sizeof(*ss))
+		return -EINVAL;
+
+	if (cmd->size_out != 0)
+		return -EINVAL;
+
+	mdata->shutdown_state = ss->state;
+	return 0;
+}
+
 static struct mock_poison {
 	struct cxl_dev_state *cxlds;
 	u64 dpa;
@@ -1421,6 +1441,9 @@ static int cxl_mock_mbox_send(struct cxl_mailbox *cxl_mbox,
 	case CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE:
 		rc = mock_passphrase_secure_erase(mdata, cmd);
 		break;
+	case CXL_MBOX_OP_SET_SHUTDOWN_STATE:
+		rc = mock_set_shutdown_state(mdata, cmd);
+		break;
 	case CXL_MBOX_OP_GET_POISON:
 		rc = mock_get_poison(cxlds, cmd);
 		break;