intel: Introduce SMC support for mailbox command

This update allows normal world to send mailbox commands through SMC
Signed-off-by: Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I587bea06422da90e5907d586495cd9e3bde900f6

plat/intel/soc/common/include/socfpga_sip_svc.h

@@ -28,6 +28,7 @@
 #define INTEL_SIP_LEGACY_SMC_ECC_DBE			0xC200000D
 #define INTEL_SIP_SMC_RSU_NOTIFY			0xC200000E
 #define INTEL_SIP_SMC_RSU_RETRY_COUNTER			0xC200000F
+#define INTEL_SIP_SMC_MBOX_SEND_CMD			0xC200001E
 
 /* FPGA config helpers */
 #define INTEL_SIP_SMC_FPGA_CONFIG_ADDR			0x400000

plat/intel/soc/common/socfpga_sip_svc.c

@@ -400,6 +400,26 @@ static uint32_t intel_rsu_retry_counter(uint32_t *respbuf, uint32_t respbuf_sz,
 	return INTEL_SIP_SMC_STATUS_OK;
 }
 
+/* Mailbox services */
+static uint32_t intel_mbox_send_cmd(uint32_t cmd, uint32_t *args, int len,
+				    int urgent, uint32_t *response,
+				    int resp_len, int *mbox_status,
+				    int *len_in_resp)
+{
+	int status = mailbox_send_cmd(MBOX_JOB_ID, cmd, args, len, urgent,
+				      response, resp_len);
+
+	if (status < 0) {
+		*len_in_resp = 0;
+		*mbox_status = -status;
+		return INTEL_SIP_SMC_STATUS_ERROR;
+	}
+
+	*mbox_status = 0;
+	*len_in_resp = status;
+	return INTEL_SIP_SMC_STATUS_OK;
+}
+
 /*
  * This function is responsible for handling all SiP calls from the NS world
  */
@@ -418,6 +438,8 @@ uintptr_t sip_smc_handler(uint32_t smc_fid,
 	uint32_t completed_addr[3];
 	uint64_t rsu_respbuf[9];
 	uint32_t count = 0;
+	u_register_t x5, x6;
+	int mbox_status, len_in_resp;
 
 	switch (smc_fid) {
 	case SIP_SVC_UID:
@@ -509,6 +531,14 @@ uintptr_t sip_smc_handler(uint32_t smc_fid,
 			SMC_RET2(handle, status, val);
 		}
 
+	case INTEL_SIP_SMC_MBOX_SEND_CMD:
+		x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
+		x6 = SMC_GET_GP(handle, CTX_GPREG_X6);
+		status = intel_mbox_send_cmd(x1, (uint32_t *)x2, x3, x4,
+					     (uint32_t *)x5, x6, &mbox_status,
+					     &len_in_resp);
+		SMC_RET4(handle, status, mbox_status, x5, len_in_resp);
+
 	default:
 		return socfpga_sip_handler(smc_fid, x1, x2, x3, x4,
 			cookie, handle, flags);