synquacer: Retrieve DRAM info from SCP firmware

Retrieve DRAM info from SCP firmware using SCPI driver. Board supports
multiple DRAM slots so its required to fetch DRAM info from SCP firmware
and pass this info to UEFI via non-secure SRAM.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

plat/socionext/synquacer/drivers/scpi/sq_scpi.c

@@ -168,3 +168,49 @@ uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
 
 	return response.status;
 }
+
+uint32_t scpi_get_draminfo(struct draminfo *info)
+{
+	scpi_cmd_t *cmd;
+	struct {
+		scpi_cmd_t	cmd;
+		struct draminfo	info;
+	} response;
+	uint32_t mhu_status;
+
+	scpi_secure_message_start();
+
+	/* Populate the command header */
+	cmd		= SCPI_CMD_HEADER_AP_TO_SCP;
+	cmd->id		= SCPI_CMD_GET_DRAMINFO;
+	cmd->set	= SCPI_SET_EXTENDED;
+	cmd->sender	= 0;
+	cmd->size	= 0;
+
+	scpi_secure_message_send(0);
+
+	mhu_status = mhu_secure_message_wait();
+
+	/* Expect an SCPI message, reject any other protocol */
+	if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
+		ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
+			mhu_status);
+		panic();
+	}
+
+	/*
+	 * Ensure that any read to the SCPI payload area is done after reading
+	 * the MHU register. If these 2 reads were reordered then the CPU would
+	 * read invalid payload data
+	 */
+	dmbld();
+
+	memcpy(&response, (void *)SCPI_SHARED_MEM_SCP_TO_AP, sizeof(response));
+
+	scpi_secure_message_end();
+
+	if (response.cmd.status == SCP_OK)
+		*info = response.info;
+
+	return response.cmd.status;
+}

plat/socionext/synquacer/include/platform_def.h

@@ -54,6 +54,8 @@
 #define SQ_SYS_TIMCTL_BASE		0x2a810000
 #define PLAT_SQ_NSTIMER_FRAME_ID	0
 
+#define DRAMINFO_BASE			0x2E00FFC0
+
 #define PLAT_SQ_MHU_BASE		0x45000000
 
 #define PLAT_SQ_SCP_COM_SHARED_MEM_BASE		0x45400000

plat/socionext/synquacer/include/sq_common.h

@@ -10,6 +10,19 @@
 #include <sys/types.h>
 #include <xlat_tables_v2.h>
 
+struct draminfo {
+	uint32_t	num_regions;
+	uint32_t	reserved;
+	uint64_t	base1;
+	uint64_t	size1;
+	uint64_t	base2;
+	uint64_t	size2;
+	uint64_t	base3;
+	uint64_t	size3;
+};
+
+uint32_t scpi_get_draminfo(struct draminfo *info);
+
 void plat_sq_pwrc_setup(void);
 
 void plat_sq_interconnect_init(void);

plat/socionext/synquacer/sq_bl31_setup.c

@@ -132,6 +132,9 @@ void bl31_platform_setup(void)
 
 void bl31_plat_runtime_setup(void)
 {
+	struct draminfo *di = (struct draminfo *)(unsigned long)DRAMINFO_BASE;
+
+	scpi_get_draminfo(di);
 }
 
 void bl31_plat_arch_setup(void)