Disable IRQ and FIQ in IRQ/ABT/SVC/UND thread handlers for arm32

Disable native and foreign interrupts in thread handlers for arm32.
The tee handlers can decide when the native interrupts can be enabled.

Signed-off-by: David Wang <david.wang@arm.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>

core/arch/arm/kernel/thread_a32.S

@@ -662,6 +662,12 @@ LOCAL_FUNC thread_abort_handler , :
 thread_und_handler:
 UNWIND(	.fnstart)
 UNWIND(	.cantunwind)
+	/*
+	 * Disable both foreign and native interrupts in the thread handlers.
+	 * The tee handlers can decide when the native interrupts should
+	 * be enabled.
+	 */
+	cpsid	f	/* IRQ is already masked by the hardware */
 	strd	r0, r1, [sp, #THREAD_CORE_LOCAL_R0]
 	mrs	r1, spsr
 	tst	r1, #CPSR_T
@@ -671,12 +677,24 @@ UNWIND(	.cantunwind)
 	b	.thread_abort_generic
 
 thread_dabort_handler:
+	/*
+	 * Disable both foreign and native interrupts in the thread handlers.
+	 * The tee handlers can decide when the native interrupts should
+	 * be enabled.
+	 */
+	cpsid	f	/* IRQ is already masked by the hardware */
 	strd	r0, r1, [sp, #THREAD_CORE_LOCAL_R0]
 	sub	lr, lr, #8
 	mov	r0, #ABORT_TYPE_DATA
 	b	.thread_abort_generic
 
 thread_pabort_handler:
+	/*
+	 * Disable both foreign and native interrupts in the thread handlers.
+	 * The tee handlers can decide when the native interrupts should
+	 * be enabled.
+	 */
+	cpsid	f	/* IRQ is already masked by the hardware */
 	strd	r0, r1, [sp, #THREAD_CORE_LOCAL_R0]
 	sub	lr, lr, #4
 	mov	r0, #ABORT_TYPE_PREFETCH
@@ -771,6 +789,12 @@ END_FUNC thread_abort_handler
 LOCAL_FUNC thread_svc_handler , :
 UNWIND(	.fnstart)
 UNWIND(	.cantunwind)
+	/*
+	 * Disable both foreign and native interrupts in the thread handlers.
+	 * The tee handlers can decide when the native interrupts should
+	 * be enabled.
+	 */
+	cpsid	f	/* IRQ is already masked by the hardware */
 	push	{r0-r7, lr}
 	mrs	r0, spsr
 	push	{r0}

core/arch/arm/tee/arch_svc.c

@@ -196,10 +196,15 @@ void __weak tee_svc_handler(struct thread_svc_regs *regs)
 	size_t scn;
 	size_t max_args;
 	syscall_t scf;
+	uint32_t state;
 
 	COMPILE_TIME_ASSERT(ARRAY_SIZE(tee_svc_syscall_table) ==
 				(TEE_SCN_MAX + 1));
 
+	/* Enable native interupts */
+	state = thread_get_exceptions();
+	thread_unmask_exceptions(state & ~THREAD_EXCP_NATIVE_INTR);
+
 	thread_user_save_vfp();
 
 	/* TA has just entered kernel mode */