MN10300: Specify an ELF HWCAP flag for MN10300 Atomic Operations Unit support

Use an ELF HWCAP flag to indicate to the process that the CPU provides LL/SC
equivalent atomic operations unit support in addition to BSET/BCLR.
Signed-off-by: NMark Salter <msalter@redhat.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

arch/mn10300/include/asm/elf.h

@@ -31,6 +31,12 @@
 #define R_MN10300_SYM_DIFF	33	/* Adjustment when relaxing. */
 #define R_MN10300_ALIGN 	34	/* Alignment requirement. */
 
+/*
+ * AM33/AM34 HW Capabilities
+ */
+#define HWCAP_MN10300_ATOMIC_OP_UNIT	1	/* Has AM34 Atomic Operations */
+
+
 /*
  * ELF register definitions..
  */
@@ -128,7 +134,11 @@ do {						\
  * instruction set this CPU supports.  This could be done in user space,
  * but it's not easy, and we've already done it here.
  */
+#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+#define ELF_HWCAP	(HWCAP_MN10300_ATOMIC_OP_UNIT)
+#else
 #define ELF_HWCAP	(0)
+#endif
 
 /*
  * This yields a string that ld.so will use to load implementation