ARC: Cache: Move I$ entire operation to a separate function

Move instruction cache entire operation to a separate function
because we are planing to use it in other places like
sync_icache_dcache_all().

Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

arch/arc/lib/cache.c

@@ -315,20 +315,27 @@ void icache_disable(void)
 			      IC_CTRL_CACHE_DISABLE);
 }
 
-void invalidate_icache_all(void)
+/* IC supports only invalidation */
+static inline void __ic_entire_invalidate(void)
 {
+	if (!icache_status())
+		return;
+
 	/* Any write to IC_IVIC register triggers invalidation of entire I$ */
-	if (icache_status()) {
-		write_aux_reg(ARC_AUX_IC_IVIC, 1);
-		/*
-		 * As per ARC HS databook (see chapter 5.3.3.2)
-		 * it is required to add 3 NOPs after each write to IC_IVIC.
-		 */
-		__builtin_arc_nop();
-		__builtin_arc_nop();
-		__builtin_arc_nop();
-		read_aux_reg(ARC_AUX_IC_CTRL);	/* blocks */
-	}
+	write_aux_reg(ARC_AUX_IC_IVIC, 1);
+	/*
+	 * As per ARC HS databook (see chapter 5.3.3.2)
+	 * it is required to add 3 NOPs after each write to IC_IVIC.
+	 */
+	__builtin_arc_nop();
+	__builtin_arc_nop();
+	__builtin_arc_nop();
+	read_aux_reg(ARC_AUX_IC_CTRL);  /* blocks */
+}
+
+void invalidate_icache_all(void)
+{
+	__ic_entire_invalidate();
 
 #ifdef CONFIG_ISA_ARCV2
 	if (slc_exists)