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>
diff --git a/plat/arm/css/drivers/scp/css_bom_bootloader.c b/plat/arm/css/drivers/scp/css_bom_bootloader.c
new file mode 100644
index 0000000..e4a44fe
--- /dev/null
+++ b/plat/arm/css/drivers/scp/css_bom_bootloader.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2014-2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <css_def.h>
+#include <debug.h>
+#include <platform.h>
+#include <stdint.h>
+#include "../scpi/css_mhu.h"
+
+/* ID of the MHU slot used for the BOM protocol */
+#define BOM_MHU_SLOT_ID 0
+
+/* Boot commands sent from AP -> SCP */
+#define BOOT_CMD_INFO 0x00
+#define BOOT_CMD_DATA 0x01
+
+/* BOM command header */
+typedef struct {
+ uint32_t id : 8;
+ uint32_t reserved : 24;
+} bom_cmd_t;
+
+typedef struct {
+ uint32_t image_size;
+ uint32_t checksum;
+} cmd_info_payload_t;
+
+/*
+ * Unlike the SCPI protocol, the boot protocol uses the same memory region
+ * for both AP -> SCP and SCP -> AP transfers; define the address of this...
+ */
+#define BOM_SHARED_MEM PLAT_CSS_SCP_COM_SHARED_MEM_BASE
+#define BOM_CMD_HEADER ((bom_cmd_t *) BOM_SHARED_MEM)
+#define BOM_CMD_PAYLOAD ((void *) (BOM_SHARED_MEM + sizeof(bom_cmd_t)))
+
+typedef struct {
+ /* Offset from the base address of the Trusted RAM */
+ uint32_t offset;
+ uint32_t block_size;
+} cmd_data_payload_t;
+
+static void scp_boot_message_start(void)
+{
+ mhu_secure_message_start(BOM_MHU_SLOT_ID);
+}
+
+static void scp_boot_message_send(size_t payload_size)
+{
+ /* Ensure that any write to the BOM payload area is seen by SCP before
+ * we write to the MHU register. If these 2 writes were reordered by
+ * the CPU then SCP would read stale payload data */
+ dmbst();
+
+ /* Send command to SCP */
+ mhu_secure_message_send(BOM_MHU_SLOT_ID);
+}
+
+static uint32_t scp_boot_message_wait(size_t size)
+{
+ uint32_t mhu_status;
+
+ mhu_status = mhu_secure_message_wait();
+
+ /* Expect an SCP Boot Protocol message, reject any other protocol */
+ if (mhu_status != (1 << BOM_MHU_SLOT_ID)) {
+ ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
+ mhu_status);
+ panic();
+ }
+
+ /* Ensure that any read to the BOM payload area is done after reading
+ * the MHU register. If these 2 reads were reordered then the CPU would
+ * read invalid payload data */
+ dmbld();
+
+ return *(uint32_t *) BOM_SHARED_MEM;
+}
+
+static void scp_boot_message_end(void)
+{
+ mhu_secure_message_end(BOM_MHU_SLOT_ID);
+}
+
+int css_scp_boot_image_xfer(void *image, unsigned int image_size)
+{
+ uint32_t response;
+ uint32_t checksum;
+ cmd_info_payload_t *cmd_info_payload;
+ cmd_data_payload_t *cmd_data_payload;
+
+ assert((uintptr_t) image == SCP_BL2_BASE);
+
+ if ((image_size == 0) || (image_size % 4 != 0)) {
+ ERROR("Invalid size for the SCP_BL2 image. Must be a multiple of "
+ "4 bytes and not zero (current size = 0x%x)\n",
+ image_size);
+ return -1;
+ }
+
+ /* Extract the checksum from the image */
+ checksum = *(uint32_t *) image;
+ image = (char *) image + sizeof(checksum);
+ image_size -= sizeof(checksum);
+
+ mhu_secure_init();
+
+ VERBOSE("Send info about the SCP_BL2 image to be transferred to SCP\n");
+
+ /*
+ * Send information about the SCP firmware image about to be transferred
+ * to SCP
+ */
+ scp_boot_message_start();
+
+ BOM_CMD_HEADER->id = BOOT_CMD_INFO;
+ cmd_info_payload = BOM_CMD_PAYLOAD;
+ cmd_info_payload->image_size = image_size;
+ cmd_info_payload->checksum = checksum;
+
+ scp_boot_message_send(sizeof(*cmd_info_payload));
+#if CSS_DETECT_PRE_1_7_0_SCP
+ {
+ const uint32_t deprecated_scp_nack_cmd = 0x404;
+ uint32_t mhu_status;
+
+ VERBOSE("Detecting SCP version incompatibility\n");
+
+ mhu_status = mhu_secure_message_wait();
+ if (mhu_status == deprecated_scp_nack_cmd) {
+ ERROR("Detected an incompatible version of the SCP firmware.\n");
+ ERROR("Only versions from v1.7.0 onwards are supported.\n");
+ ERROR("Please update the SCP firmware.\n");
+ return -1;
+ }
+
+ VERBOSE("SCP version looks OK\n");
+ }
+#endif /* CSS_DETECT_PRE_1_7_0_SCP */
+ response = scp_boot_message_wait(sizeof(response));
+ scp_boot_message_end();
+
+ if (response != 0) {
+ ERROR("SCP BOOT_CMD_INFO returned error %u\n", response);
+ return -1;
+ }
+
+ VERBOSE("Transferring SCP_BL2 image to SCP\n");
+
+ /* Transfer SCP_BL2 image to SCP */
+ scp_boot_message_start();
+
+ BOM_CMD_HEADER->id = BOOT_CMD_DATA;
+ cmd_data_payload = BOM_CMD_PAYLOAD;
+ cmd_data_payload->offset = (uintptr_t) image - ARM_TRUSTED_SRAM_BASE;
+ cmd_data_payload->block_size = image_size;
+
+ scp_boot_message_send(sizeof(*cmd_data_payload));
+ response = scp_boot_message_wait(sizeof(response));
+ scp_boot_message_end();
+
+ if (response != 0) {
+ ERROR("SCP BOOT_CMD_DATA returned error %u\n", response);
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/plat/arm/css/drivers/scp/css_scp.h b/plat/arm/css/drivers/scp/css_scp.h
index 165226d..097a9f5 100644
--- a/plat/arm/css/drivers/scp/css_scp.h
+++ b/plat/arm/css/drivers/scp/css_scp.h
@@ -1,5 +1,5 @@
/*
- * 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__ */
diff --git a/plat/arm/css/drivers/scpi/css_scpi.h b/plat/arm/css/drivers/scpi/css_scpi.h
index 0e26c3d..2a7e624 100644
--- a/plat/arm/css/drivers/scpi/css_scpi.h
+++ b/plat/arm/css/drivers/scpi/css_scpi.h
@@ -1,5 +1,5 @@
/*
- * 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
*/
@@ -97,11 +97,11 @@
scpi_system_reset = 2
} scpi_system_state_t;
-extern int scpi_wait_ready(void);
-extern 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);
+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);
int scpi_get_css_power_state(unsigned int mpidr, unsigned int *cpu_state_p,
unsigned int *cluster_state_p);
uint32_t scpi_sys_power_state(scpi_system_state_t system_state);