feat(stm32mp1): rework SVC services

Having two generations of STM32MPX using the same SMCCC protocol,
rework the SVC services setup to put in common what can be put
in common and implement platform-specific handlers.

Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
Signed-off-by: Maxime Méré <maxime.mere@foss.st.com>
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: I000573e50d55dc70163c2657c12cc84085416f6b
diff --git a/plat/st/common/include/stm32mp_svc_setup.h b/plat/st/common/include/stm32mp_svc_setup.h
new file mode 100644
index 0000000..e0e0d7f
--- /dev/null
+++ b/plat/st/common/include/stm32mp_svc_setup.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2024, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef STM32MP_SVC_SETUP_H
+#define STM32MP_SVC_SETUP_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+/* Common SMC function IDs for STM32 Service queries across STM32MP paltforms */
+#define STM32_SIP_SVC_CALL_COUNT	0x8200ff00
+#define STM32_SIP_SVC_UID		0x8200ff01
+/*					0x8200ff02 is reserved */
+#define STM32_SIP_SVC_VERSION		0x8200ff03
+
+/* STM32 SiP Service Calls version numbers */
+#define STM32_SIP_SVC_VERSION_MAJOR	0x0
+#define STM32_SIP_SVC_VERSION_MINOR	0x1
+
+/* SMC error codes */
+#define STM32_SMC_OK			0x00000000U
+#define STM32_SMC_NOT_SUPPORTED		0xFFFFFFFFU
+#define STM32_SMC_FAILED		0xFFFFFFFEU
+#define STM32_SMC_INVALID_PARAMS	0xFFFFFFFDU
+
+void plat_svc_smc_handler(uint32_t smc_fid, u_register_t x1,
+			  u_register_t x2, u_register_t x3,
+			  u_register_t x4, uint32_t *ret1,
+			  uint32_t *ret2, bool *ret2_enabled,
+			  u_register_t flags);
+
+#endif /* STM32MP_SVC_SETUP_H */
diff --git a/plat/st/common/stm32mp_svc_setup.c b/plat/st/common/stm32mp_svc_setup.c
new file mode 100644
index 0000000..7fce896
--- /dev/null
+++ b/plat/st/common/stm32mp_svc_setup.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2014-2024, STMicroelectronics - All Rights Reserved
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <common/debug.h>
+#include <common/runtime_svc.h>
+#include <drivers/scmi-msg.h>
+#include <lib/psci/psci.h>
+#include <platform_def.h>
+#include <tools_share/uuid.h>
+
+#include <stm32mp_svc_setup.h>
+
+/* STM32 SiP Service UUID */
+DEFINE_SVC_UUID2(stm32_sip_svc_uid,
+		 0xa778aa50, 0xf49b, 0x144a, 0x8a, 0x5e,
+		 0x26, 0x4d, 0x59, 0x94, 0xc2, 0x14);
+
+/* Setup STM32MP Standard Services */
+static int32_t stm32mp_svc_setup(void)
+{
+	/*
+	 * PSCI is the only specification implemented as a Standard Service.
+	 * Invoke PSCI setup from here.
+	 */
+	return 0;
+}
+
+/*
+ * Top-level Standard Service SMC handler. This handler will dispatch the SMC
+ * to the correct feature handler or default call a platform handler
+ */
+static uintptr_t stm32mp_svc_smc_handler(uint32_t smc_fid, u_register_t x1,
+					 u_register_t x2, u_register_t x3,
+					 u_register_t x4, void *cookie,
+					 void *handle, u_register_t flags)
+{
+	uint32_t ret1 = 0U, ret2 = 0U;
+	bool ret_uid = false, ret2_enabled = false;
+
+	switch (smc_fid) {
+	case STM32_SIP_SVC_UID:
+		/* Return UUID to the caller */
+		ret_uid = true;
+		break;
+
+	case STM32_SIP_SVC_VERSION:
+		/* Return the version of current implementation */
+		ret1 = STM32_SIP_SVC_VERSION_MAJOR;
+		ret2 = STM32_SIP_SVC_VERSION_MINOR;
+		ret2_enabled = true;
+		break;
+	default:
+		plat_svc_smc_handler(smc_fid, x1, x2, x3, x4, &ret1, &ret2, &ret2_enabled, flags);
+		break;
+	}
+
+	if (ret_uid) {
+		SMC_UUID_RET(handle, stm32_sip_svc_uid);
+	}
+
+	if (ret2_enabled) {
+		SMC_RET2(handle, ret1, ret2);
+	}
+
+	SMC_RET1(handle, ret1);
+}
+
+/* Register Standard Service Calls as runtime service */
+DECLARE_RT_SVC(stm32mp_sip_svc,
+	       OEN_SIP_START,
+	       OEN_SIP_END,
+	       SMC_TYPE_FAST,
+	       stm32mp_svc_setup,
+	       stm32mp_svc_smc_handler
+);