--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#ifndef _SMC_API_H_
+#define _SMC_API_H_
+
+int invoke_smc(u32 func_id, u64 *args, int arg_len, u64 *ret_arg, int ret_len);
+int smc_send_mailbox(u32 cmd, u32 len, u32 *arg, u8 urgent, u32 *resp_buf_len,
+ u32 *resp_buf);
+
+#endif /* _SMC_API_H_ */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Intel Corporation <www.intel.com>
+ *
+ */
+
+#include <common.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <linux/intel-smc.h>
+
+int invoke_smc(u32 func_id, u64 *args, int arg_len, u64 *ret_arg, int ret_len)
+{
+ struct pt_regs regs;
+
+ memset(®s, 0, sizeof(regs));
+ regs.regs[0] = func_id;
+
+ if (args)
+ memcpy(®s.regs[1], args, arg_len * sizeof(*args));
+
+ smc_call(®s);
+
+ if (ret_arg)
+ memcpy(ret_arg, ®s.regs[1], ret_len * sizeof(*ret_arg));
+
+ return regs.regs[0];
+}
+
+int smc_send_mailbox(u32 cmd, u32 len, u32 *arg, u8 urgent, u32 *resp_buf_len,
+ u32 *resp_buf)
+{
+ int ret;
+ u64 args[6];
+ u64 resp[3];
+
+ args[0] = cmd;
+ args[1] = (u64)arg;
+ args[2] = len;
+ args[3] = urgent;
+ args[4] = (u64)resp_buf;
+ if (resp_buf_len)
+ args[5] = *resp_buf_len;
+ else
+ args[5] = 0;
+
+ ret = invoke_smc(INTEL_SIP_SMC_MBOX_SEND_CMD, args, ARRAY_SIZE(args),
+ resp, ARRAY_SIZE(resp));
+
+ if (ret == INTEL_SIP_SMC_STATUS_OK && resp_buf && resp_buf_len) {
+ if (!resp[0])
+ *resp_buf_len = resp[1];
+ }
+
+ return (int)resp[0];
+}