diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index d9928641deb9..49d9fb68632d 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -401,3 +401,7 @@ The following keys are defined:
     as defined in version 1.0 of the RISC-V Control-flow Integrity (CFI)
     extensions specification, ratified in commit 302a2d45c243
     ("Update build-pdf.yml") of riscv-cfi.
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICCLSM`: The Zicclsm extension is supported,
+    as defined in the RISC-V Profiles specification starting from commit
+    b1d80660 ("Updated to ratified state.")
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index c0cb576b134f..1e80e634bb0f 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -118,6 +118,7 @@
 #define RISCV_ISA_EXT_SSCCFG		109
 #define RISCV_ISA_EXT_SMCDELEG		110
 #define RISCV_ISA_EXT_SSQOSID		111
+#define RISCV_ISA_EXT_ZICCLSM		112
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 9139edba0aec..6819df159c51 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -116,6 +116,7 @@ struct riscv_hwprobe {
 #define RISCV_HWPROBE_KEY_ZICBOP_BLOCK_SIZE	15
 #define RISCV_HWPROBE_KEY_IMA_EXT_1		16
 #define		RISCV_HWPROBE_EXT_ZICFISS	(1ULL << 0)
+#define		RISCV_HWPROBE_EXT_ZICCLSM	(1ULL << 1)
 
 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 16488b33f238..05e05f42fa93 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -525,6 +525,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicbom, RISCV_ISA_EXT_ZICBOM, riscv_xlinuxenvcfg_exts, riscv_ext_zicbom_validate),
 	__RISCV_ISA_EXT_DATA_VALIDATE(zicbop, RISCV_ISA_EXT_ZICBOP, riscv_ext_zicbop_validate),
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicboz, RISCV_ISA_EXT_ZICBOZ, riscv_xlinuxenvcfg_exts, riscv_ext_zicboz_validate),
+	__RISCV_ISA_EXT_DATA(zicclsm, RISCV_ISA_EXT_ZICCLSM),
 	__RISCV_ISA_EXT_DATA(ziccrse, RISCV_ISA_EXT_ZICCRSE),
 	__RISCV_ISA_EXT_SUPERSET_VALIDATE(zicfilp, RISCV_ISA_EXT_ZICFILP, riscv_xlinuxenvcfg_exts,
 					  riscv_cfilp_validate),
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 5d6732641c57..70dc1d6136c8 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -202,6 +202,7 @@ static void hwprobe_isa_ext1(struct riscv_hwprobe *pair,
 		 * in the hart_isa bitmap, are made.
 		 */
 		EXT_KEY(isainfo->isa, ZICFISS, pair->value, missing);
+		EXT_KEY(isainfo->isa, ZICCLSM, pair->value, missing);
 	}
 
 	/* Now turn off reporting features if any CPU is missing it. */