diff --git a/bl32/tsp/tsp_main.c b/bl32/tsp/tsp_main.c
index 55e1532..522c1b4 100644
--- a/bl32/tsp/tsp_main.c
+++ b/bl32/tsp/tsp_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -370,6 +370,7 @@
 	uint64_t service_arg1;
 	uint64_t results[2];
 	uint32_t linear_id = plat_my_core_pos();
+	u_register_t dit;
 
 	/* Update this cpu's statistics */
 	tsp_stats[linear_id].smc_count++;
@@ -424,6 +425,23 @@
 		results[0] /= service_arg0 ? service_arg0 : 1;
 		results[1] /= service_arg1 ? service_arg1 : 1;
 		break;
+	case TSP_CHECK_DIT:
+		if (!is_armv8_4_dit_present()) {
+#if LOG_LEVEL >= LOG_LEVEL_ERROR
+			spin_lock(&console_lock);
+			ERROR("DIT not supported\n");
+			spin_unlock(&console_lock);
+#endif
+			results[0] = 0;
+			results[1] = 0xffff;
+			break;
+		}
+		dit = read_dit();
+		results[0] = dit == service_arg0;
+		results[1] = dit;
+		/* Toggle the dit bit */
+		write_dit(service_arg0 != 0U ? 0 : DIT_BIT);
+		break;
 	default:
 		break;
 	}
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 46cd1c9..a260f03 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2019-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -46,6 +46,12 @@
 	return (read_id_aa64isar1_el1() & mask) != 0U;
 }
 
+static inline bool is_armv8_4_dit_present(void)
+{
+	return ((read_id_aa64pfr0_el1() >> ID_AA64PFR0_DIT_SHIFT) &
+		ID_AA64PFR0_DIT_MASK) == 1U;
+}
+
 static inline bool is_armv8_4_ttst_present(void)
 {
 	return ((read_id_aa64mmfr2_el1() >> ID_AA64MMFR2_EL1_ST_SHIFT) &
diff --git a/include/arch/aarch64/arch_helpers.h b/include/arch/aarch64/arch_helpers.h
index 733bb23..009eb90 100644
--- a/include/arch/aarch64/arch_helpers.h
+++ b/include/arch/aarch64/arch_helpers.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2021, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -529,6 +529,9 @@
 DEFINE_RENAME_SYSREG_RW_FUNCS(apiakeyhi_el1, APIAKeyHi_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(apiakeylo_el1, APIAKeyLo_EL1)
 
+/* Armv8.4 Data Independent Timing Register */
+DEFINE_RENAME_SYSREG_RW_FUNCS(dit, DIT)
+
 /* Armv8.5 MTE Registers */
 DEFINE_RENAME_SYSREG_RW_FUNCS(tfsre0_el1, TFSRE0_EL1)
 DEFINE_RENAME_SYSREG_RW_FUNCS(tfsr_el1, TFSR_EL1)
diff --git a/include/bl32/tsp/tsp.h b/include/bl32/tsp/tsp.h
index 637e14a..285bfbe 100644
--- a/include/bl32/tsp/tsp.h
+++ b/include/bl32/tsp/tsp.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -41,6 +41,7 @@
 #define TSP_MUL		0x2002
 #define TSP_DIV		0x2003
 #define TSP_HANDLE_SEL1_INTR_AND_RETURN	0x2004
+#define TSP_CHECK_DIT	0x2005
 
 /*
  * Identify a TSP service from function ID filtering the last 16 bits from the
diff --git a/services/spd/tspd/tspd_main.c b/services/spd/tspd/tspd_main.c
index 29fc238..6cb4992 100644
--- a/services/spd/tspd/tspd_main.c
+++ b/services/spd/tspd/tspd_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2022, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -570,6 +570,11 @@
 	case TSP_YIELD_FID(TSP_SUB):
 	case TSP_YIELD_FID(TSP_MUL):
 	case TSP_YIELD_FID(TSP_DIV):
+		/*
+		 * Request from non-secure client to perform a check
+		 * of the DIT PSTATE bit.
+		 */
+	case TSP_YIELD_FID(TSP_CHECK_DIT):
 		if (ns) {
 			/*
 			 * This is a fresh request from the non-secure client.