diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index 0ceda71b32ca..b2bcc9eed9aa 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -175,6 +175,19 @@ The following keys are defined:
        defined in the RISC-V ISA manual starting from commit 056b6ff467c7
        ("Zfa is ratified").
 
+  * :c:macro:`RISCV_HWPROBE_EXT_ZTSO`: The Ztso extension is supported as
+       defined in the RISC-V ISA manual starting from commit 5618fb5a216b
+       ("Ztso is now ratified.")
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZACAS`: The Zacas extension is supported as
+       defined in the Atomic Compare-and-Swap (CAS) instructions manual starting
+       from commit 5059e0ca641c ("update to ratified").
+
+  * :c:macro:`RISCV_HWPROBE_EXT_ZICOND`: The Zicond extension is supported as
+       defined in the RISC-V Integer Conditional (Zicond) operations extension
+       manual starting from commit 95cf1f9 ("Add changes requested by Ved
+       during signoff")
+
 * :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance
   information about the selected set of processors.
 
diff --git a/Documentation/devicetree/bindings/riscv/extensions.yaml b/Documentation/devicetree/bindings/riscv/extensions.yaml
index 3574a0b70be4..27beedb98198 100644
--- a/Documentation/devicetree/bindings/riscv/extensions.yaml
+++ b/Documentation/devicetree/bindings/riscv/extensions.yaml
@@ -171,6 +171,12 @@ properties:
             memory types as ratified in the 20191213 version of the privileged
             ISA specification.
 
+        - const: zacas
+          description: |
+            The Zacas extension for Atomic Compare-and-Swap (CAS) instructions
+            is supported as ratified at commit 5059e0ca641c ("update to
+            ratified") of the riscv-zacas.
+
         - const: zba
           description: |
             The standard Zba bit-manipulation extension for address generation
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index e1a0bd4f394a..5340f818746b 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -78,6 +78,8 @@
 #define RISCV_ISA_EXT_ZVFH		69
 #define RISCV_ISA_EXT_ZVFHMIN		70
 #define RISCV_ISA_EXT_ZFA		71
+#define RISCV_ISA_EXT_ZTSO		72
+#define RISCV_ISA_EXT_ZACAS		73
 
 #define RISCV_ISA_EXT_MAX		128
 #define RISCV_ISA_EXT_INVALID		U32_MAX
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index 12062a6345c4..9f2a8e3ff204 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -56,6 +56,9 @@ struct riscv_hwprobe {
 #define		RISCV_HWPROBE_EXT_ZVFH		(1 << 30)
 #define		RISCV_HWPROBE_EXT_ZVFHMIN	(1 << 31)
 #define		RISCV_HWPROBE_EXT_ZFA		(1ULL << 32)
+#define		RISCV_HWPROBE_EXT_ZTSO		(1ULL << 33)
+#define		RISCV_HWPROBE_EXT_ZACAS		(1ULL << 34)
+#define		RISCV_HWPROBE_EXT_ZICOND	(1ULL << 35)
 #define RISCV_HWPROBE_KEY_CPUPERF_0	5
 #define		RISCV_HWPROBE_MISALIGNED_UNKNOWN	(0 << 0)
 #define		RISCV_HWPROBE_MISALIGNED_EMULATED	(1 << 0)
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index b06c8830a194..e32591e9da90 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -255,6 +255,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(zihintntl, RISCV_ISA_EXT_ZIHINTNTL),
 	__RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE),
 	__RISCV_ISA_EXT_DATA(zihpm, RISCV_ISA_EXT_ZIHPM),
+	__RISCV_ISA_EXT_DATA(zacas, RISCV_ISA_EXT_ZACAS),
 	__RISCV_ISA_EXT_DATA(zfa, RISCV_ISA_EXT_ZFA),
 	__RISCV_ISA_EXT_DATA(zfh, RISCV_ISA_EXT_ZFH),
 	__RISCV_ISA_EXT_DATA(zfhmin, RISCV_ISA_EXT_ZFHMIN),
@@ -275,6 +276,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_DATA(zkt, RISCV_ISA_EXT_ZKT),
 	__RISCV_ISA_EXT_DATA(zksed, RISCV_ISA_EXT_ZKSED),
 	__RISCV_ISA_EXT_DATA(zksh, RISCV_ISA_EXT_ZKSH),
+	__RISCV_ISA_EXT_DATA(ztso, RISCV_ISA_EXT_ZTSO),
 	__RISCV_ISA_EXT_SUPERSET(zvbb, RISCV_ISA_EXT_ZVBB, riscv_zvbb_exts),
 	__RISCV_ISA_EXT_DATA(zvbc, RISCV_ISA_EXT_ZVBC),
 	__RISCV_ISA_EXT_DATA(zvfh, RISCV_ISA_EXT_ZVFH),
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index e9ac91fec97d..a7c56b41efd2 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -108,6 +108,9 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair,
 		EXT_KEY(ZKSH);
 		EXT_KEY(ZKT);
 		EXT_KEY(ZIHINTNTL);
+		EXT_KEY(ZTSO);
+		EXT_KEY(ZACAS);
+		EXT_KEY(ZICOND);
 
 		if (has_vector()) {
 			EXT_KEY(ZVBB);