arch: support customized up_cpu_index() in AMP mode

Some app with same code runs on different cores in AMP mode,
need the physical core on which the function is called.

Signed-off-by: hujun5 <hujun5@xiaomi.com>
Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>

arch/sim/include/irq.h

@@ -86,23 +86,13 @@ EXTERN volatile xcpt_reg_t *g_current_regs[CONFIG_SMP_NCPUS];
  * Name: up_cpu_index
  *
  * Description:
- *   Return an index in the range of 0 through (CONFIG_SMP_NCPUS-1) that
- *   corresponds to the currently executing CPU.
- *
- * Input Parameters:
- *   None
- *
- * Returned Value:
- *   An integer index in the range of 0 through (CONFIG_SMP_NCPUS-1) that
- *   corresponds to the currently executing CPU.
+ *   Return the real core number regardless CONFIG_SMP setting
  *
  ****************************************************************************/
 
-#ifdef CONFIG_SMP
-int up_cpu_index(void);
-#else
-#  define up_cpu_index() (0)
-#endif
+#ifdef CONFIG_ARCH_HAVE_MULTICPU
+int up_cpu_index(void) noinstrument_function;
+#endif /* CONFIG_ARCH_HAVE_MULTICPU */
 
 /* Name: up_irq_save, up_irq_restore, and friends.
  *
@@ -124,12 +114,20 @@ void up_irq_enable(void);
 
 static inline_function xcpt_reg_t *up_current_regs(void)
 {
+#ifdef CONFIG_SMP
   return (xcpt_reg_t *)g_current_regs[up_cpu_index()];
+#else
+  return (xcpt_reg_t *)g_current_regs[0];
+#endif
 }
 
 static inline_function void up_set_current_regs(xcpt_reg_t *regs)
 {
+#ifdef CONFIG_SMP
   g_current_regs[up_cpu_index()] = regs;
+#else
+  g_current_regs[0] = regs;
+#endif
 }
 
 /* Return the current value of the stack pointer */