diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 17516afc389a..0e571f6483d9 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -247,6 +247,9 @@
 #define CSR_SIP			0x144
 #define CSR_SATP		0x180
 
+#define CSR_STIMECMP		0x14D
+#define CSR_STIMECMPH		0x15D
+
 #define CSR_VSSTATUS		0x200
 #define CSR_VSIE		0x204
 #define CSR_VSTVEC		0x205
@@ -256,6 +259,8 @@
 #define CSR_VSTVAL		0x243
 #define CSR_VSIP		0x244
 #define CSR_VSATP		0x280
+#define CSR_VSTIMECMP		0x24D
+#define CSR_VSTIMECMPH		0x25D
 
 #define CSR_HSTATUS		0x600
 #define CSR_HEDELEG		0x602
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index 3c8a5ca95c72..6f59ec64175e 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -57,6 +57,7 @@ enum riscv_isa_ext_id {
 	RISCV_ISA_EXT_SVPBMT,
 	RISCV_ISA_EXT_ZICBOM,
 	RISCV_ISA_EXT_ZIHINTPAUSE,
+	RISCV_ISA_EXT_SSTC,
 	RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
 };
 
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index a77c380703c5..0be8a2403212 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -95,6 +95,7 @@ static struct riscv_isa_ext_data isa_ext_arr[] = {
 	__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
 	__RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM),
 	__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
+	__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
 	__RISCV_ISA_EXT_DATA("", RISCV_ISA_EXT_MAX),
 };
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index c233fbc5b873..553d755483ed 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -203,6 +203,7 @@ void __init riscv_fill_hwcap(void)
 				SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT);
 				SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM);
 				SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
+				SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
 			}
 #undef SET_ISA_EXT_MAP
 		}
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index e460df7ed799..969a552da8d2 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -7,6 +7,9 @@
  * either be read from the "time" and "timeh" CSRs, and can use the SBI to
  * setup events, or directly accessed using MMIO registers.
  */
+
+#define pr_fmt(fmt) "riscv-timer: " fmt
+
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/cpu.h>
@@ -20,14 +23,28 @@
 #include <linux/of_irq.h>
 #include <clocksource/timer-riscv.h>
 #include <asm/smp.h>
+#include <asm/hwcap.h>
 #include <asm/sbi.h>
 #include <asm/timex.h>
 
+static DEFINE_STATIC_KEY_FALSE(riscv_sstc_available);
+
 static int riscv_clock_next_event(unsigned long delta,
 		struct clock_event_device *ce)
 {
+	u64 next_tval = get_cycles64() + delta;
+
 	csr_set(CSR_IE, IE_TIE);
-	sbi_set_timer(get_cycles64() + delta);
+	if (static_branch_likely(&riscv_sstc_available)) {
+#if defined(CONFIG_32BIT)
+		csr_write(CSR_STIMECMP, next_tval & 0xFFFFFFFF);
+		csr_write(CSR_STIMECMPH, next_tval >> 32);
+#else
+		csr_write(CSR_STIMECMP, next_tval);
+#endif
+	} else
+		sbi_set_timer(next_tval);
+
 	return 0;
 }
 
@@ -166,6 +183,12 @@ static int __init riscv_timer_init_dt(struct device_node *n)
 	if (error)
 		pr_err("cpu hp setup state failed for RISCV timer [%d]\n",
 		       error);
+
+	if (riscv_isa_extension_available(NULL, SSTC)) {
+		pr_info("Timer interrupt in S-mode is available via sstc extension\n");
+		static_branch_enable(&riscv_sstc_available);
+	}
+
 	return error;
 }