arch: arm: aarch32: cortex_a_r: disable interrupts before context switching

Ultil now Cortex A/R aarch32 implementation for context
switching expects that interrupts was disabled. This is
true if a context switching happens at thread context.

But if a context switching happens at last action during
interrupt context, this assumption is not true because the
interrupts are still enabled (to allow nesting interrupts).

Disable interrupts at the last interrupt action to ensure
the interrupts are always disabled before context switching
is processed

Signed-off-by: Dat Nguyen Duy <[email protected]>

Author: Dat-NguyenDuy

arch/arm/core/aarch32/cortex_a_r/exc_exit.S

@@ -129,6 +129,11 @@ SECTION_SUBSEC_FUNC(TEXT, _HandlerModeExit, z_arm_int_exit)
 	bl z_check_stack_sentinel
 #endif /* CONFIG_STACK_SENTINEL */
 
+	/* Disable nested interrupts while exiting, this should happens
+	 * before context switch also, to ensure interrupts are disabled.
+	 */
+	cpsid i
+
 #ifdef CONFIG_PREEMPT_ENABLED
 	/* Do not context switch if exiting a nested interrupt */
 	ldr r3, =_kernel
@@ -143,9 +148,6 @@ SECTION_SUBSEC_FUNC(TEXT, _HandlerModeExit, z_arm_int_exit)
 __EXIT_INT:
 #endif /* CONFIG_PREEMPT_ENABLED */
 
-	/* Disable nested interrupts while exiting */
-	cpsid i
-
 	/* Decrement interrupt nesting count */
 	ldr r2, =_kernel
 	ldr r0, [r2, #_kernel_offset_to_nested]