diff --git a/plat/arm/board/rde1edge/include/platform_def.h b/plat/arm/board/rde1edge/include/platform_def.h
index c39fe2b69..a9b30a41d 100644
--- a/plat/arm/board/rde1edge/include/platform_def.h
+++ b/plat/arm/board/rde1edge/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/board/rde1edge/rde1edge_security.c b/plat/arm/board/rde1edge/rde1edge_security.c
index 2123e0931..35f81d19f 100644
--- a/plat/arm/board/rde1edge/rde1edge_security.c
+++ b/plat/arm/board/rde1edge/rde1edge_security.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2021, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,7 +7,7 @@
 #include <platform_def.h>
 
 #include <common/debug.h>
-#include <drivers/arm/tzc_dmc620.h>
+#include <sgi_dmc620_tzc_regions.h>
 
 uintptr_t rde1edge_dmc_base[] = {
 	RDE1EDGE_DMC620_BASE0,
@@ -20,11 +20,7 @@ static const tzc_dmc620_driver_data_t rde1edge_plat_driver_data = {
 };
 
 static const tzc_dmc620_acc_addr_data_t rde1edge_acc_addr_data[] = {
-	{
-		.region_base = ARM_AP_TZC_DRAM1_BASE,
-		.region_top = ARM_AP_TZC_DRAM1_BASE + ARM_TZC_DRAM1_SIZE - 1,
-		.sec_attr = TZC_DMC620_REGION_S_RDWR
-	}
+	CSS_SGI_DMC620_TZC_REGIONS_DEF
 };
 
 static const tzc_dmc620_config_data_t rde1edge_plat_config_data = {
diff --git a/plat/arm/board/rdn1edge/include/platform_def.h b/plat/arm/board/rdn1edge/include/platform_def.h
index b167c46e0..a61b0d555 100644
--- a/plat/arm/board/rdn1edge/include/platform_def.h
+++ b/plat/arm/board/rdn1edge/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/board/rdn1edge/rdn1edge_security.c b/plat/arm/board/rdn1edge/rdn1edge_security.c
index ffa893524..49435329b 100644
--- a/plat/arm/board/rdn1edge/rdn1edge_security.c
+++ b/plat/arm/board/rdn1edge/rdn1edge_security.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, ARM Limited. All rights reserved.
+ * Copyright (c) 2019-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,7 +7,7 @@
 #include <platform_def.h>
 
 #include <common/debug.h>
-#include <drivers/arm/tzc_dmc620.h>
+#include <sgi_dmc620_tzc_regions.h>
 
 uintptr_t rdn1edge_dmc_base[] = {
 	RDN1EDGE_DMC620_BASE0,
@@ -20,11 +20,7 @@ static const tzc_dmc620_driver_data_t rdn1edge_plat_driver_data = {
 };
 
 static const tzc_dmc620_acc_addr_data_t rdn1edge_acc_addr_data[] = {
-	{
-		.region_base = ARM_AP_TZC_DRAM1_BASE,
-		.region_top = ARM_AP_TZC_DRAM1_BASE + ARM_TZC_DRAM1_SIZE - 1,
-		.sec_attr = TZC_DMC620_REGION_S_RDWR
-	}
+	CSS_SGI_DMC620_TZC_REGIONS_DEF
 };
 
 static const tzc_dmc620_config_data_t rdn1edge_plat_config_data = {
diff --git a/plat/arm/board/rdv1mc/include/platform_def.h b/plat/arm/board/rdv1mc/include/platform_def.h
index 112b2102b..12ce8063a 100644
--- a/plat/arm/board/rdv1mc/include/platform_def.h
+++ b/plat/arm/board/rdv1mc/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -20,6 +20,29 @@
 #define CSS_SYSTEM_PWR_DMN_LVL		ARM_PWR_LVL2
 #define PLAT_MAX_PWR_LVL		ARM_PWR_LVL1
 
+/* TZC Related Constants */
+#define PLAT_ARM_TZC_BASE		UL(0x21830000)
+#define TZC400_BASE(n)			(PLAT_ARM_TZC_BASE + \
+					 (n * TZC400_OFFSET))
+#define TZC400_OFFSET			UL(0x1000000)
+#define TZC400_COUNT			U(8)
+#define PLAT_ARM_TZC_FILTERS		TZC_400_REGION_ATTR_FILTER_BIT(0)
+
+#define TZC_NSAID_ALL_AP		U(0)
+#define TZC_NSAID_PCI			U(1)
+#define TZC_NSAID_HDLCD0		U(2)
+#define TZC_NSAID_CLCD			U(7)
+#define TZC_NSAID_AP			U(9)
+#define TZC_NSAID_VIRTIO		U(15)
+
+#define PLAT_ARM_TZC_NS_DEV_ACCESS	\
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_ALL_AP)) | \
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_HDLCD0)) | \
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_PCI))    | \
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_AP))     | \
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_CLCD))   | \
+		(TZC_REGION_ACCESS_RDWR(TZC_NSAID_VIRTIO))
+
 /* Virtual address used by dynamic mem_protect for chunk_base */
 #define PLAT_ARM_MEM_PROTEC_VA_FRAME	UL(0xC0000000)
 
diff --git a/plat/arm/board/rdv1mc/platform.mk b/plat/arm/board/rdv1mc/platform.mk
index 50728416a..fb057936a 100644
--- a/plat/arm/board/rdv1mc/platform.mk
+++ b/plat/arm/board/rdv1mc/platform.mk
@@ -1,4 +1,4 @@
-# Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -23,6 +23,8 @@ BL1_SOURCES		+=	${SGI_CPU_SOURCES}			\
 BL2_SOURCES		+=	${RDV1MC_BASE}/rdv1mc_plat.c	\
 				${RDV1MC_BASE}/rdv1mc_security.c	\
 				${RDV1MC_BASE}/rdv1mc_err.c	\
+				drivers/arm/tzc/tzc400.c	\
+				plat/arm/common/arm_tzc400.c	\
 				lib/utils/mem_region.c			\
 				plat/arm/common/arm_nor_psci_mem_protect.c
 
diff --git a/plat/arm/board/rdv1mc/rdv1mc_security.c b/plat/arm/board/rdv1mc/rdv1mc_security.c
index 541f800a8..adc0bf816 100644
--- a/plat/arm/board/rdv1mc/rdv1mc_security.c
+++ b/plat/arm/board/rdv1mc/rdv1mc_security.c
@@ -1,10 +1,64 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <common/debug.h>
+#include <plat/arm/common/plat_arm.h>
+#include <platform_def.h>
+
+/* TZC memory regions for the first chip */
+static const arm_tzc_regions_info_t tzc_regions[] = {
+	ARM_TZC_REGIONS_DEF,
+	{}
+};
+
+#if CSS_SGI_CHIP_COUNT > 1
+static const arm_tzc_regions_info_t tzc_regions_mc[][CSS_SGI_CHIP_COUNT - 1] = {
+	{
+		/* TZC memory regions for second chip */
+		SGI_PLAT_TZC_NS_REMOTE_REGIONS_DEF(1),
+		{}
+	},
+#if CSS_SGI_CHIP_COUNT > 2
+	{
+		/* TZC memory regions for third chip */
+		SGI_PLAT_TZC_NS_REMOTE_REGIONS_DEF(2),
+		{}
+	},
+#endif
+#if CSS_SGI_CHIP_COUNT > 3
+	{
+		/* TZC memory regions for fourth chip */
+		SGI_PLAT_TZC_NS_REMOTE_REGIONS_DEF(3),
+		{}
+	},
+#endif
+};
+#endif /* CSS_SGI_CHIP_COUNT */
+
 /* Initialize the secure environment */
 void plat_arm_security_setup(void)
 {
+	unsigned int i;
+
+	INFO("Configuring TrustZone Controller for Chip 0\n");
+
+	for (i = 0; i < TZC400_COUNT; i++) {
+		arm_tzc400_setup(TZC400_BASE(i), tzc_regions);
+	}
+
+#if CSS_SGI_CHIP_COUNT > 1
+	unsigned int j;
+
+	for (i = 1; i < CSS_SGI_CHIP_COUNT; i++) {
+		INFO("Configuring TrustZone Controller for Chip %u\n", i);
+
+		for (j = 0; j < TZC400_COUNT; j++) {
+			arm_tzc400_setup(CSS_SGI_REMOTE_CHIP_MEM_OFFSET(i)
+				+ TZC400_BASE(j), tzc_regions_mc[i-1]);
+		}
+	}
+#endif
 }
diff --git a/plat/arm/board/sgi575/include/platform_def.h b/plat/arm/board/sgi575/include/platform_def.h
index c929334cd..72d5f7cf0 100644
--- a/plat/arm/board/sgi575/include/platform_def.h
+++ b/plat/arm/board/sgi575/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,6 +9,7 @@
 
 #include <lib/utils_def.h>
 
+#include <sgi_sdei.h>
 #include <sgi_soc_platform_def.h>
 
 #define PLAT_ARM_CLUSTER_COUNT		U(2)
diff --git a/plat/arm/board/sgi575/sgi575_security.c b/plat/arm/board/sgi575/sgi575_security.c
index 440f18d55..17d07d1a1 100644
--- a/plat/arm/board/sgi575/sgi575_security.c
+++ b/plat/arm/board/sgi575/sgi575_security.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,8 +7,7 @@
 #include <platform_def.h>
 
 #include <common/debug.h>
-#include <drivers/arm/tzc_dmc620.h>
-#include <plat/arm/common/plat_arm.h>
+#include <sgi_dmc620_tzc_regions.h>
 
 uintptr_t sgi575_dmc_base[] = {
 	SGI575_DMC620_BASE0,
@@ -21,11 +20,7 @@ static const tzc_dmc620_driver_data_t sgi575_plat_driver_data = {
 };
 
 static const tzc_dmc620_acc_addr_data_t sgi575_acc_addr_data[] = {
-	{
-		.region_base = ARM_AP_TZC_DRAM1_BASE,
-		.region_top = ARM_AP_TZC_DRAM1_BASE + ARM_TZC_DRAM1_SIZE - 1,
-		.sec_attr = TZC_DMC620_REGION_S_RDWR
-	}
+	CSS_SGI_DMC620_TZC_REGIONS_DEF
 };
 
 static const tzc_dmc620_config_data_t sgi575_plat_config_data = {
diff --git a/plat/arm/css/sgi/include/sgi_base_platform_def.h b/plat/arm/css/sgi/include/sgi_base_platform_def.h
index b805746de..d795f258e 100644
--- a/plat/arm/css/sgi/include/sgi_base_platform_def.h
+++ b/plat/arm/css/sgi/include/sgi_base_platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -26,14 +26,17 @@
 
 /*
  * PLAT_ARM_MMAP_ENTRIES depends on the number of entries in the
- * plat_arm_mmap array defined for each BL stage.
+ * plat_arm_mmap array defined for each BL stage. In addition to that, on
+ * multi-chip platforms, address regions on each of the remote chips are
+ * also mapped. In BL31, for instance, three address regions on the remote
+ * chips are accessed - secure ram, css device and soc device regions.
  */
 #if defined(IMAGE_BL31)
 # if SPM_MM
-#  define PLAT_ARM_MMAP_ENTRIES		9
-#  define MAX_XLAT_TABLES		7
-#  define PLAT_SP_IMAGE_MMAP_REGIONS	7
-#  define PLAT_SP_IMAGE_MAX_XLAT_TABLES	10
+#  define PLAT_ARM_MMAP_ENTRIES		(9  + ((CSS_SGI_CHIP_COUNT - 1) * 3))
+#  define MAX_XLAT_TABLES		(7  + ((CSS_SGI_CHIP_COUNT - 1) * 3))
+#  define PLAT_SP_IMAGE_MMAP_REGIONS	9
+#  define PLAT_SP_IMAGE_MAX_XLAT_TABLES	11
 # else
 #  define PLAT_ARM_MMAP_ENTRIES		(5 + ((CSS_SGI_CHIP_COUNT - 1) * 3))
 #  define MAX_XLAT_TABLES		(6 + ((CSS_SGI_CHIP_COUNT - 1) * 3))
@@ -41,6 +44,17 @@
 #elif defined(IMAGE_BL32)
 # define PLAT_ARM_MMAP_ENTRIES		8
 # define MAX_XLAT_TABLES		5
+#elif defined(IMAGE_BL2)
+# define PLAT_ARM_MMAP_ENTRIES		(11 + (CSS_SGI_CHIP_COUNT - 1))
+
+/*
+ * MAX_XLAT_TABLES entries need to be doubled because when the address width
+ * exceeds 40 bits an additional level of translation is required. In case of
+ * multichip platforms peripherals also fall into address space with width
+ * > 40 bits
+ *
+ */
+# define MAX_XLAT_TABLES		(7  + ((CSS_SGI_CHIP_COUNT - 1) * 2))
 #elif !USE_ROMLIB
 # define PLAT_ARM_MMAP_ENTRIES		11
 # define MAX_XLAT_TABLES		7
@@ -69,12 +83,17 @@
 
 /*
  * PLAT_ARM_MAX_BL2_SIZE is calculated using the current BL2 debug size plus a
- * little space for growth.
+ * little space for growth. Additional 8KiB space is added per chip in
+ * order to accommodate the additional level of translation required for "TZC"
+ * peripheral access which lies in >4TB address space.
+ *
  */
 #if TRUSTED_BOARD_BOOT
-# define PLAT_ARM_MAX_BL2_SIZE		0x1D000
+# define PLAT_ARM_MAX_BL2_SIZE		(0x1D000 + ((CSS_SGI_CHIP_COUNT - 1) * \
+							0x2000))
 #else
-# define PLAT_ARM_MAX_BL2_SIZE		0x14000
+# define PLAT_ARM_MAX_BL2_SIZE		(0x14000 + ((CSS_SGI_CHIP_COUNT - 1) * \
+							0x2000))
 #endif
 
 /*
@@ -165,48 +184,36 @@
 
 #define PLAT_SP_PRI				PLAT_RAS_PRI
 
-#if RAS_EXTENSION
-/* Allocate 128KB for CPER buffers */
-#define PLAT_SP_BUF_BASE			ULL(0x20000)
-
-#define PLAT_ARM_SP_IMAGE_STACK_BASE		(PLAT_SP_IMAGE_NS_BUF_BASE + \
-						PLAT_SP_IMAGE_NS_BUF_SIZE + \
-						PLAT_SP_BUF_BASE)
-
-/* Platform specific SMC FID's used for RAS */
-#define SP_DMC_ERROR_INJECT_EVENT_AARCH64	0xC4000042
-#define SP_DMC_ERROR_INJECT_EVENT_AARCH32	0x84000042
-
-#define SP_DMC_ERROR_OVERFLOW_EVENT_AARCH64	0xC4000043
-#define SP_DMC_ERROR_OVERFLOW_EVENT_AARCH32	0x84000043
-
-#define SP_DMC_ERROR_ECC_EVENT_AARCH64		0xC4000044
-#define SP_DMC_ERROR_ECC_EVENT_AARCH32		0x84000044
-
-/* ARM SDEI dynamic shared event numbers */
-#define SGI_SDEI_DS_EVENT_0			804
-#define SGI_SDEI_DS_EVENT_1			805
-
-#define PLAT_ARM_PRIVATE_SDEI_EVENTS	\
-	SDEI_DEFINE_EVENT_0(ARM_SDEI_SGI), \
-	SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_0, SDEI_MAPF_CRITICAL), \
-	SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_1, SDEI_MAPF_CRITICAL),
-#define PLAT_ARM_SHARED_SDEI_EVENTS
-
-#define ARM_SP_CPER_BUF_BASE			(PLAT_SP_IMAGE_NS_BUF_BASE + \
-						PLAT_SP_IMAGE_NS_BUF_SIZE)
-#define ARM_SP_CPER_BUF_SIZE			ULL(0x20000)
-#define ARM_SP_CPER_BUF_MMAP			MAP_REGION2(		\
-						ARM_SP_CPER_BUF_BASE,	\
-						ARM_SP_CPER_BUF_BASE,	\
-						ARM_SP_CPER_BUF_SIZE,	\
-						MT_RW_DATA | MT_NS | MT_USER, \
+#if SPM_MM && RAS_EXTENSION
+/*
+ * CPER buffer memory of 128KB is reserved and it is placed adjacent to the
+ * memory shared between EL3 and S-EL0.
+ */
+#define CSS_SGI_SP_CPER_BUF_BASE	(PLAT_SP_IMAGE_NS_BUF_BASE + \
+					 PLAT_SP_IMAGE_NS_BUF_SIZE)
+#define CSS_SGI_SP_CPER_BUF_SIZE	ULL(0x20000)
+#define CSS_SGI_SP_CPER_BUF_MMAP	MAP_REGION2(			       \
+						CSS_SGI_SP_CPER_BUF_BASE,      \
+						CSS_SGI_SP_CPER_BUF_BASE,      \
+						CSS_SGI_SP_CPER_BUF_SIZE,      \
+						MT_RW_DATA | MT_NS | MT_USER,  \
 						PAGE_SIZE)
 
-#else
+/*
+ * Secure partition stack follows right after the memory space reserved for
+ * CPER buffer memory.
+ */
+#define PLAT_ARM_SP_IMAGE_STACK_BASE		(PLAT_SP_IMAGE_NS_BUF_BASE +   \
+						 PLAT_SP_IMAGE_NS_BUF_SIZE +   \
+						 CSS_SGI_SP_CPER_BUF_SIZE)
+#elif SPM_MM
+/*
+ * Secure partition stack follows right after the memory region that is shared
+ * between EL3 and S-EL0.
+ */
 #define PLAT_ARM_SP_IMAGE_STACK_BASE	(PLAT_SP_IMAGE_NS_BUF_BASE +	\
 					 PLAT_SP_IMAGE_NS_BUF_SIZE)
-#endif /* RAS_EXTENSION */
+#endif /* SPM_MM && RAS_EXTENSION */
 
 /* Platform ID address */
 #define SSC_VERSION                     (SSC_REG_BASE + SSC_VERSION_OFFSET)
@@ -238,4 +245,17 @@
 /* Number of SCMI channels on the platform */
 #define PLAT_ARM_SCMI_CHANNEL_COUNT	CSS_SGI_CHIP_COUNT
 
+/*
+ * Mapping definition of the TrustZone Controller for ARM SGI/RD platforms
+ * where both the DRAM regions are marked for non-secure access. This applies
+ * to multi-chip platforms.
+ */
+#define SGI_PLAT_TZC_NS_REMOTE_REGIONS_DEF(n)				\
+	{CSS_SGI_REMOTE_CHIP_MEM_OFFSET(n) + ARM_DRAM1_BASE,		\
+		CSS_SGI_REMOTE_CHIP_MEM_OFFSET(n) + ARM_DRAM1_END,	\
+		ARM_TZC_NS_DRAM_S_ACCESS, PLAT_ARM_TZC_NS_DEV_ACCESS},	\
+	{CSS_SGI_REMOTE_CHIP_MEM_OFFSET(n) + ARM_DRAM2_BASE,		\
+		CSS_SGI_REMOTE_CHIP_MEM_OFFSET(n) + ARM_DRAM2_END,	\
+		ARM_TZC_NS_DRAM_S_ACCESS, PLAT_ARM_TZC_NS_DEV_ACCESS}
+
 #endif /* SGI_BASE_PLATFORM_DEF_H */
diff --git a/plat/arm/css/sgi/include/sgi_dmc620_tzc_regions.h b/plat/arm/css/sgi/include/sgi_dmc620_tzc_regions.h
new file mode 100644
index 000000000..e93916318
--- /dev/null
+++ b/plat/arm/css/sgi/include/sgi_dmc620_tzc_regions.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SGI_DMC620_TZC_REGIONS_H
+#define SGI_DMC620_TZC_REGIONS_H
+
+#include <drivers/arm/tzc_dmc620.h>
+
+#if SPM_MM
+#define CSS_SGI_DMC620_TZC_REGIONS_DEF				\
+	{							\
+		.region_base = ARM_AP_TZC_DRAM1_BASE,		\
+		.region_top = PLAT_SP_IMAGE_NS_BUF_BASE - 1,	\
+		.sec_attr = TZC_DMC620_REGION_S_RDWR		\
+	}, {							\
+		.region_base = PLAT_SP_IMAGE_NS_BUF_BASE,	\
+		.region_top = PLAT_ARM_SP_IMAGE_STACK_BASE - 1,	\
+		.sec_attr = TZC_DMC620_REGION_S_NS_RDWR		\
+	}, {							\
+		.region_base = PLAT_ARM_SP_IMAGE_STACK_BASE,	\
+		.region_top = ARM_AP_TZC_DRAM1_END,		\
+		.sec_attr = TZC_DMC620_REGION_S_RDWR		\
+	}
+#else
+#define CSS_SGI_DMC620_TZC_REGIONS_DEF				\
+	{							\
+		.region_base = ARM_AP_TZC_DRAM1_BASE,		\
+		.region_top = ARM_AP_TZC_DRAM1_END,		\
+		.sec_attr = TZC_DMC620_REGION_S_RDWR		\
+	}
+#endif /* SPM_MM */
+
+#endif /* SGI_DMC620_TZC_REGIONS_H */
diff --git a/plat/arm/css/sgi/include/sgi_ras.h b/plat/arm/css/sgi/include/sgi_ras.h
index a449eae26..4b8a0d182 100644
--- a/plat/arm/css/sgi/include/sgi_ras.h
+++ b/plat/arm/css/sgi/include/sgi_ras.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -7,6 +7,10 @@
 #ifndef SGI_RAS_H
 #define SGI_RAS_H
 
+/* Platform specific SMC FID's used for DMC-620 RAS error handling */
+#define SP_DMC_ERROR_OVERFLOW_EVENT_AARCH64	0xC4000043
+#define SP_DMC_ERROR_ECC_EVENT_AARCH64		0xC4000044
+
 /*
  * Mapping the RAS interrupt with SDEI event number and the event
  * id used with Standalone MM code
diff --git a/plat/arm/css/sgi/include/sgi_sdei.h b/plat/arm/css/sgi/include/sgi_sdei.h
new file mode 100644
index 000000000..f380122bb
--- /dev/null
+++ b/plat/arm/css/sgi/include/sgi_sdei.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef SGI_SDEI_H
+#define SGI_SDEI_H
+
+#if SDEI_SUPPORT
+
+/* ARM SDEI dynamic shared event numbers */
+#define SGI_SDEI_DS_EVENT_0		U(804)
+#define SGI_SDEI_DS_EVENT_1		U(805)
+
+#define PLAT_ARM_PRIVATE_SDEI_EVENTS					      \
+		SDEI_DEFINE_EVENT_0(ARM_SDEI_SGI),			      \
+		SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_0, SDEI_MAPF_CRITICAL), \
+		SDEI_EXPLICIT_EVENT(SGI_SDEI_DS_EVENT_1, SDEI_MAPF_CRITICAL),
+
+#define PLAT_ARM_SHARED_SDEI_EVENTS
+
+#endif /* SDEI_SUPPORT */
+
+#endif /* SGI_SDEI_H */
diff --git a/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h b/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
index 03f107367..103dd9a7a 100644
--- a/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
+++ b/plat/arm/css/sgi/include/sgi_soc_css_def_v2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -70,6 +70,18 @@
 						SOC_PLATFORM_PERIPH_SIZE, 	\
 						MT_DEVICE | MT_RW | MT_SECURE)
 
+#if SPM_MM
+/*
+ * Memory map definition for the platform peripheral memory region that is
+ * accessible from S-EL0 (with secure user mode access).
+ */
+#define SOC_PLATFORM_PERIPH_MAP_DEVICE_USER				       \
+		MAP_REGION_FLAT(					       \
+			SOC_PLATFORM_PERIPH_BASE,			       \
+			SOC_PLATFORM_PERIPH_SIZE,			       \
+			MT_DEVICE | MT_RW | MT_SECURE | MT_USER)
+#endif
+
 #define SOC_SYSTEM_PERIPH_MAP_DEVICE	MAP_REGION_FLAT(			\
 						SOC_SYSTEM_PERIPH_BASE,		\
 						SOC_SYSTEM_PERIPH_SIZE,		\
diff --git a/plat/arm/css/sgi/include/sgi_soc_platform_def.h b/plat/arm/css/sgi/include/sgi_soc_platform_def.h
index d7a839a52..405d62f12 100644
--- a/plat/arm/css/sgi/include/sgi_soc_platform_def.h
+++ b/plat/arm/css/sgi/include/sgi_soc_platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -12,4 +12,22 @@
 #include <plat/arm/board/common/v2m_def.h>
 #include <plat/arm/soc/common/soc_css_def.h>
 
+/* Map the System registers to access from S-EL0 */
+#define CSS_SYSTEMREG_DEVICE_BASE	(0x1C010000)
+#define CSS_SYSTEMREG_DEVICE_SIZE	(0x00010000)
+#define PLAT_ARM_SECURE_MAP_SYSTEMREG	MAP_REGION_FLAT(		    \
+						CSS_SYSTEMREG_DEVICE_BASE,  \
+						CSS_SYSTEMREG_DEVICE_SIZE,  \
+						(MT_DEVICE | MT_RW |	    \
+						 MT_SECURE | MT_USER))
+
+/* Map the NOR2 Flash to access from S-EL0 */
+#define CSS_NOR2_FLASH_DEVICE_BASE	(0x10000000)
+#define CSS_NOR2_FLASH_DEVICE_SIZE	(0x04000000)
+#define PLAT_ARM_SECURE_MAP_NOR2	MAP_REGION_FLAT(                    \
+						CSS_NOR2_FLASH_DEVICE_BASE, \
+						CSS_NOR2_FLASH_DEVICE_SIZE, \
+						(MT_DEVICE | MT_RW |	    \
+						 MT_SECURE | MT_USER))
+
 #endif /* SGI_SOC_PLATFORM_DEF_H */
diff --git a/plat/arm/css/sgi/include/sgi_soc_platform_def_v2.h b/plat/arm/css/sgi/include/sgi_soc_platform_def_v2.h
index cb747c34a..20dd6825d 100644
--- a/plat/arm/css/sgi/include/sgi_soc_platform_def_v2.h
+++ b/plat/arm/css/sgi/include/sgi_soc_platform_def_v2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020-2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -10,4 +10,22 @@
 #include <sgi_base_platform_def.h>
 #include <sgi_soc_css_def_v2.h>
 
+/* Map the System registers to access from S-EL0 */
+#define CSS_SYSTEMREG_DEVICE_BASE	(0x0C010000)
+#define CSS_SYSTEMREG_DEVICE_SIZE	(0x00010000)
+#define PLAT_ARM_SECURE_MAP_SYSTEMREG	MAP_REGION_FLAT(                    \
+						CSS_SYSTEMREG_DEVICE_BASE,  \
+						CSS_SYSTEMREG_DEVICE_SIZE,  \
+						(MT_DEVICE | MT_RW |	    \
+						 MT_SECURE | MT_USER))
+
+/* Map the NOR2 Flash to access from S-EL0 */
+#define CSS_NOR2_FLASH_DEVICE_BASE	(0x001054000000)
+#define CSS_NOR2_FLASH_DEVICE_SIZE	(0x000004000000)
+#define PLAT_ARM_SECURE_MAP_NOR2	MAP_REGION_FLAT(                    \
+						CSS_NOR2_FLASH_DEVICE_BASE, \
+						CSS_NOR2_FLASH_DEVICE_SIZE, \
+						(MT_DEVICE | MT_RW |	    \
+						 MT_SECURE | MT_USER))
+
 #endif /* SGI_SOC_PLATFORM_DEF_V2_H */
diff --git a/plat/arm/css/sgi/sgi_plat.c b/plat/arm/css/sgi/sgi_plat.c
index 39eb89eb8..20c52e9c5 100644
--- a/plat/arm/css/sgi/sgi_plat.c
+++ b/plat/arm/css/sgi/sgi_plat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2021, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -49,6 +49,15 @@ const mmap_region_t plat_arm_mmap[] = {
 	CSS_SGI_MAP_DEVICE,
 	SOC_CSS_MAP_DEVICE,
 	ARM_MAP_NS_DRAM1,
+#if CSS_SGI_CHIP_COUNT > 1
+	CSS_SGI_MAP_DEVICE_REMOTE_CHIP(1),
+#endif
+#if CSS_SGI_CHIP_COUNT > 2
+	CSS_SGI_MAP_DEVICE_REMOTE_CHIP(2),
+#endif
+#if CSS_SGI_CHIP_COUNT > 3
+	CSS_SGI_MAP_DEVICE_REMOTE_CHIP(3),
+#endif
 #if ARM_BL31_IN_DRAM
 	ARM_MAP_BL31_SEC_DRAM,
 #endif
@@ -78,10 +87,14 @@ const mmap_region_t plat_arm_mmap[] = {
 
 #if SPM_MM && defined(IMAGE_BL31)
 const mmap_region_t plat_arm_secure_partition_mmap[] = {
+	PLAT_ARM_SECURE_MAP_SYSTEMREG,
+	PLAT_ARM_SECURE_MAP_NOR2,
 	PLAT_ARM_SECURE_MAP_DEVICE,
 	ARM_SP_IMAGE_MMAP,
 	ARM_SP_IMAGE_NS_BUF_MMAP,
-	ARM_SP_CPER_BUF_MMAP,
+#if RAS_EXTENSION
+	CSS_SGI_SP_CPER_BUF_MMAP,
+#endif
 	ARM_SP_IMAGE_RW_MMAP,
 	ARM_SPM_BUF_EL0_MMAP,
 	{0}
diff --git a/plat/arm/css/sgi/sgi_plat_v2.c b/plat/arm/css/sgi/sgi_plat_v2.c
index a770255fc..131cdf2b5 100644
--- a/plat/arm/css/sgi/sgi_plat_v2.c
+++ b/plat/arm/css/sgi/sgi_plat_v2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -12,6 +12,10 @@
 #include <plat/common/platform.h>
 #include <drivers/arm/sbsa.h>
 
+#if SPM_MM
+#include <services/spm_mm_partition.h>
+#endif
+
 /*
  * Table of regions for different BL stages to map using the MMU.
  */
@@ -41,6 +45,9 @@ const mmap_region_t plat_arm_mmap[] = {
 #if ARM_BL31_IN_DRAM
 	ARM_MAP_BL31_SEC_DRAM,
 #endif
+#if SPM_MM
+	ARM_SP_IMAGE_MMAP,
+#endif
 #if TRUSTED_BOARD_BOOT && !BL2_AT_EL3
 	ARM_MAP_BL1_RW,
 #endif
@@ -57,13 +64,86 @@ const mmap_region_t plat_arm_mmap[] = {
 	CSS_SGI_MAP_DEVICE,
 	SOC_PLATFORM_PERIPH_MAP_DEVICE,
 	SOC_SYSTEM_PERIPH_MAP_DEVICE,
+#if SPM_MM
+	ARM_SPM_BUF_EL3_MMAP,
+#endif
 	{0}
 };
 
+#if SPM_MM && defined(IMAGE_BL31)
+const mmap_region_t plat_arm_secure_partition_mmap[] = {
+	PLAT_ARM_SECURE_MAP_SYSTEMREG,
+	PLAT_ARM_SECURE_MAP_NOR2,
+	SOC_PLATFORM_PERIPH_MAP_DEVICE_USER,
+	ARM_SP_IMAGE_MMAP,
+	ARM_SP_IMAGE_NS_BUF_MMAP,
+	ARM_SP_IMAGE_RW_MMAP,
+	ARM_SPM_BUF_EL0_MMAP,
+	{0}
+};
+#endif /* SPM_MM && defined(IMAGE_BL31) */
 #endif
 
 ARM_CASSERT_MMAP
 
+#if SPM_MM && defined(IMAGE_BL31)
+/*
+ * Boot information passed to a secure partition during initialisation. Linear
+ * indices in MP information will be filled at runtime.
+ */
+static spm_mm_mp_info_t sp_mp_info[] = {
+	[0] = {0x81000000, 0},
+	[1] = {0x81010000, 0},
+	[2] = {0x81020000, 0},
+	[3] = {0x81030000, 0},
+	[4] = {0x81040000, 0},
+	[5] = {0x81050000, 0},
+	[6] = {0x81060000, 0},
+	[7] = {0x81070000, 0},
+	[8] = {0x81080000, 0},
+	[9] = {0x81090000, 0},
+	[10] = {0x810a0000, 0},
+	[11] = {0x810b0000, 0},
+	[12] = {0x810c0000, 0},
+	[13] = {0x810d0000, 0},
+	[14] = {0x810e0000, 0},
+	[15] = {0x810f0000, 0},
+};
+
+const spm_mm_boot_info_t plat_arm_secure_partition_boot_info = {
+	.h.type              = PARAM_SP_IMAGE_BOOT_INFO,
+	.h.version           = VERSION_1,
+	.h.size              = sizeof(spm_mm_boot_info_t),
+	.h.attr              = 0,
+	.sp_mem_base         = ARM_SP_IMAGE_BASE,
+	.sp_mem_limit        = ARM_SP_IMAGE_LIMIT,
+	.sp_image_base       = ARM_SP_IMAGE_BASE,
+	.sp_stack_base       = PLAT_SP_IMAGE_STACK_BASE,
+	.sp_heap_base        = ARM_SP_IMAGE_HEAP_BASE,
+	.sp_ns_comm_buf_base = PLAT_SP_IMAGE_NS_BUF_BASE,
+	.sp_shared_buf_base  = PLAT_SPM_BUF_BASE,
+	.sp_image_size       = ARM_SP_IMAGE_SIZE,
+	.sp_pcpu_stack_size  = PLAT_SP_IMAGE_STACK_PCPU_SIZE,
+	.sp_heap_size        = ARM_SP_IMAGE_HEAP_SIZE,
+	.sp_ns_comm_buf_size = PLAT_SP_IMAGE_NS_BUF_SIZE,
+	.sp_shared_buf_size  = PLAT_SPM_BUF_SIZE,
+	.num_sp_mem_regions  = ARM_SP_IMAGE_NUM_MEM_REGIONS,
+	.num_cpus            = PLATFORM_CORE_COUNT,
+	.mp_info             = &sp_mp_info[0],
+};
+
+const struct mmap_region *plat_get_secure_partition_mmap(void *cookie)
+{
+	return plat_arm_secure_partition_mmap;
+}
+
+const struct spm_mm_boot_info *plat_get_secure_partition_boot_info(
+		void *cookie)
+{
+	return &plat_arm_secure_partition_boot_info;
+}
+#endif /* SPM_MM && defined(IMAGE_BL31) */
+
 #if TRUSTED_BOARD_BOOT
 int plat_get_mbedtls_heap(void **heap_addr, size_t *heap_size)
 {