arch: arc: add macros to get current cpu id

add macros for assembly and C to get current cpu id

Signed-off-by: Wayne Ren <wei.ren@synopsys.com>

arch/arc/include/swap_macros.h

@@ -295,6 +295,11 @@ extern "C" {
 	cmp \reg1, \reg2
 .endm
 
+.macro _get_cpu_id reg
+	lr \reg, [_ARC_V2_IDENTITY]
+	xbfu \reg, \reg, 0xe8
+.endm
+
 #endif /* _ASMLANGUAGE */
 
 #ifdef __cplusplus

include/arch/arc/v2/aux_regs.h

@@ -177,8 +177,19 @@ extern "C" {
 				     : "ir"(val), "i"(reg)); \
 	})
 #endif /* __GNUC__ */
+
 #endif /* _ASMLANGUAGE */
 
+#define z_arc_v2_core_id() \
+	({                                               \
+		unsigned int __ret;                      \
+		__asm__ __volatile__("lr %0, [%1]\n" \
+				     "xbfu %0, %0, 0xe8\n" \
+				     : "=r"(__ret)       \
+				     : "i"(_ARC_V2_IDENTITY));        \
+		__ret;                                   \
+	})
+
 #ifdef __cplusplus
 }
 #endif