powerpc: Add PPC_FEATURE userspace bits for SCV and DARN instructions

Providing "scv" support to userspace requires kernel support, so it
must be advertised as independently to the base ISA 3 instruction set.

The darn instruction relies on firmware enablement, so it has been
decided to split this out from the core ISA 3 feature as well.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/uapi/asm/cputable.h

@@ -46,6 +46,8 @@
 #define PPC_FEATURE2_HTM_NOSC		0x01000000
 #define PPC_FEATURE2_ARCH_3_00		0x00800000 /* ISA 3.00 */
 #define PPC_FEATURE2_HAS_IEEE128	0x00400000 /* VSX IEEE Binary Float 128-bit */
+#define PPC_FEATURE2_DARN		0x00200000 /* darn random number insn */
+#define PPC_FEATURE2_SCV		0x00100000 /* scv syscall */
 
 /*
  * IMPORTANT!

arch/powerpc/kernel/cputable.c

@@ -124,7 +124,8 @@ extern void __restore_cpu_e6500(void);
 #define COMMON_USER_POWER9	COMMON_USER_POWER8
 #define COMMON_USER2_POWER9	(COMMON_USER2_POWER8 | \
 				 PPC_FEATURE2_ARCH_3_00 | \
-				 PPC_FEATURE2_HAS_IEEE128)
+				 PPC_FEATURE2_HAS_IEEE128 | \
+				 PPC_FEATURE2_DARN )
 
 #ifdef CONFIG_PPC_BOOK3E_64
 #define COMMON_USER_BOOKE	(COMMON_USER_PPC64 | PPC_FEATURE_BOOKE)