CSS: Reorganize the SCP Image transfer functionality

The SCP_BL2 is transferred to SCP during BL2 image load and authenticate
sequence. The Boot-Over-MHU (BOM) protocol is used as transport for this. After
the SCP boots using the transferred image, the AP CPU waits till the `READY`
message is received from SCP. This patch separates the API for transport of
image from the wait for `READY` message and also moves the related files to
the `css/drivers` folder. The previous API `scp_bootloader_transfer` is
renamed to `css_scp_boot_image_xfer` to reflect the css naming convention.
This reorganisation also allows easier switch to a different transport
(eg: Shared Data Structure based transfer) in future

Change-Id: I8a96f9c4616ffde6dbfdf7c18f6f6f8bfa40bbf0
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

plat/arm/css/common/css_bl2_setup.c

@@ -11,7 +11,7 @@
 #include <plat_arm.h>
 #include <string.h>
 #include <utils.h>
-#include "css_scp_bootloader.h"
+#include "../drivers/scp/css_scp.h"
 
 /* Weak definition may be overridden in specific CSS based platform */
 #if LOAD_IMAGE_V2
@@ -34,9 +34,12 @@ int bl2_plat_handle_scp_bl2(image_info_t *scp_bl2_image_info)
 
 	INFO("BL2: Initiating SCP_BL2 transfer to SCP\n");
 
-	ret = scp_bootloader_transfer((void *)scp_bl2_image_info->image_base,
+	ret = css_scp_boot_image_xfer((void *)scp_bl2_image_info->image_base,
 		scp_bl2_image_info->image_size);
 
+	if (ret == 0)
+		ret = css_scp_boot_ready();
+
 	if (ret == 0)
 		INFO("BL2: SCP_BL2 transferred to SCP\n");
 	else

plat/arm/css/common/css_bl2u_setup.c

 /*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,7 +7,7 @@
 #include <bl_common.h>
 #include <debug.h>
 #include <plat_arm.h>
-#include "css_scp_bootloader.h"
+#include "../drivers/scp/css_scp.h"
 
 /* Weak definition may be overridden in specific CSS based platform */
 #pragma weak bl2u_plat_handle_scp_bl2u
@@ -40,9 +40,12 @@ int bl2u_plat_handle_scp_bl2u(void)
 
 	INFO("BL2U: Initiating SCP_BL2U transfer to SCP\n");
 
-	ret = scp_bootloader_transfer((void *)scp_bl2u_image_info.image_base,
+	ret = css_scp_boot_image_xfer((void *)scp_bl2u_image_info.image_base,
 		scp_bl2u_image_info.image_size);
 
+	if (ret == 0)
+		ret = css_scp_boot_ready();
+
 	if (ret == 0)
 		INFO("BL2U: SCP_BL2U transferred to SCP\n");
 	else

plat/arm/css/common/css_common.mk

@@ -56,8 +56,8 @@ ifeq (${CSS_LOAD_SCP_IMAGES},1)
     $(eval $(call FWU_FIP_ADD_IMG,SCP_BL2U,--scp-fwu-cfg))
   endif
 
-  BL2U_SOURCES		+=	plat/arm/css/common/css_scp_bootloader.c
-  BL2_SOURCES		+=	plat/arm/css/common/css_scp_bootloader.c
+  BL2U_SOURCES		+=	plat/arm/css/drivers/scp/css_bom_bootloader.c
+  BL2_SOURCES		+=	plat/arm/css/drivers/scp/css_bom_bootloader.c
 endif
 
 # Enable option to detect whether the SCP ROM firmware in use predates version

plat/arm/css/common/css_scp_bootloader.h

-/*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#ifndef __CSS_SCP_BOOTLOADER_H__
-#define __CSS_SCP_BOOTLOADER_H__
-
-int scp_bootloader_transfer(void *image, unsigned int image_size);
-
-#endif /* __CSS_SCP_BOOTLOADER_H__ */

plat/arm/css/common/css_scp_bootloader.c → plat/arm/css/drivers/scp/css_bom_bootloader.c

 /*
- * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -10,9 +10,7 @@
 #include <debug.h>
 #include <platform.h>
 #include <stdint.h>
-#include "../drivers/scpi/css_mhu.h"
-#include "../drivers/scpi/css_scpi.h"
-#include "css_scp_bootloader.h"
+#include "../scpi/css_mhu.h"
 
 /* ID of the MHU slot used for the BOM protocol */
 #define BOM_MHU_SLOT_ID		0
@@ -88,7 +86,7 @@ static void scp_boot_message_end(void)
 	mhu_secure_message_end(BOM_MHU_SLOT_ID);
 }
 
-int scp_bootloader_transfer(void *image, unsigned int image_size)
+int css_scp_boot_image_xfer(void *image, unsigned int image_size)
 {
 	uint32_t response;
 	uint32_t checksum;
@@ -170,8 +168,5 @@ int scp_bootloader_transfer(void *image, unsigned int image_size)
 		return -1;
 	}
 
-	VERBOSE("Waiting for SCP to signal it is ready to go on\n");
-
-	/* Wait for SCP to signal it's ready */
-	return scpi_wait_ready();
+	return 0;
 }

plat/arm/css/drivers/scp/css_scp.h

 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,13 +7,31 @@
 #ifndef __CSS_SCP_H__
 #define __CSS_SCP_H__
 
-#include <psci.h>
+#include <types.h>
+#include "../scpi/css_scpi.h"
 
-void css_scp_suspend(const psci_power_state_t *target_state);
-void css_scp_off(const psci_power_state_t *target_state);
+/* Forward declarations */
+struct psci_power_state;
+
+/* API for power management by SCP */
+void css_scp_suspend(const struct psci_power_state *target_state);
+void css_scp_off(const struct psci_power_state *target_state);
 void css_scp_on(u_register_t mpidr);
 int css_scp_get_power_state(u_register_t mpidr, unsigned int power_level);
 void __dead2 css_scp_sys_shutdown(void);
 void __dead2 css_scp_sys_reboot(void);
 
+/* API for SCP Boot Image transfer. Return 0 on success, -1 on error */
+int css_scp_boot_image_xfer(void *image, unsigned int image_size);
+
+/*
+ * API to wait for SCP to signal till it's ready after booting the transferred
+ * image.
+ */
+static inline int css_scp_boot_ready(void)
+{
+	VERBOSE("Waiting for SCP to signal it is ready to go on\n");
+	return scpi_wait_ready();
+}
+
 #endif	/* __CSS_SCP_H__ */

plat/arm/css/drivers/scpi/css_scpi.h

 /*
- * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -97,8 +97,8 @@ typedef enum {
 	scpi_system_reset = 2
 } scpi_system_state_t;
 
-extern int scpi_wait_ready(void);
-extern void scpi_set_css_power_state(unsigned int mpidr,
+int scpi_wait_ready(void);
+void scpi_set_css_power_state(unsigned int mpidr,
 				scpi_power_state_t cpu_state,
 				scpi_power_state_t cluster_state,
 				scpi_power_state_t css_state);