[v7 05/18] arm: socfpga: soc64: Add SMC helper function for Intel SOCFPGA (64bits)

[Siew Chin Lim <elly.siew.chin.lim@intel.com>]

From: Chee Hong Ang <chee.hong.ang@intel.com>

invoke_smc() allow U-Boot proper running in non-secure mode (EL2)
to invoke SMC call to ATF's PSCI runtime services such as
System Manager's registers access, 2nd phase bitstream FPGA
reconfiguration, Remote System Update (RSU) and etc.

smc_send_mailbox() is a send mailbox command helper function which invokes
the ATF's PSCI runtime service (function ID: INTEL_SIP_SMC_MBOX_SEND_CMD)
to send mailbox messages to Secure Device Manager (SDM).

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>
---
 arch/arm/mach-socfpga/Makefile               |  2 +
 arch/arm/mach-socfpga/include/mach/smc_api.h | 13 +++++++
 arch/arm/mach-socfpga/smc_api.c              | 56 ++++++++++++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 arch/arm/mach-socfpga/include/mach/smc_api.h
 create mode 100644 arch/arm/mach-socfpga/smc_api.c

diff --git a/arch/arm/mach-socfpga/Makefile b/arch/arm/mach-socfpga/Makefile
index c63162a5c6..0b05283a7a 100644
--- a/arch/arm/mach-socfpga/Makefile
+++ b/arch/arm/mach-socfpga/Makefile
@@ -72,6 +72,8 @@ ifdef CONFIG_TARGET_SOCFPGA_AGILEX
 obj-y	+= firewall.o
 obj-y	+= spl_agilex.o
 endif
+else
+obj-$(CONFIG_SPL_ATF) += smc_api.o
 endif
 
 ifdef CONFIG_TARGET_SOCFPGA_GEN5
diff --git a/arch/arm/mach-socfpga/include/mach/smc_api.h b/arch/arm/mach-socfpga/include/mach/smc_api.h
new file mode 100644
index 0000000000..bbefdd8dd9
--- /dev/null
+++ b/arch/arm/mach-socfpga/include/mach/smc_api.h
@@ -0,0 +1,13 @@
+/* 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_ */
diff --git a/arch/arm/mach-socfpga/smc_api.c b/arch/arm/mach-socfpga/smc_api.c
new file mode 100644
index 0000000000..085daba162
--- /dev/null
+++ b/arch/arm/mach-socfpga/smc_api.c
@@ -0,0 +1,56 @@
+// 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(&regs, 0, sizeof(regs));
+	regs.regs[0] = func_id;
+
+	if (args)
+		memcpy(&regs.regs[1], args, arg_len * sizeof(*args));
+
+	smc_call(&regs);
+
+	if (ret_arg)
+		memcpy(ret_arg, &regs.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];
+}
-- 
2.13.0