xtensa: enable kernel preemption (16c5becf) · Commits · e / devices / android_kernel_teracube_mt6765

arch/xtensa/kernel/entry.S

+17 −28

Original line number	Diff line number	Diff line
		@@ -31,7 +31,6 @@
		/* Unimplemented features. */

		#undef KERNEL_STACK_OVERFLOW_CHECK
		#undef PREEMPTIBLE_KERNEL
		#undef ALLOCA_EXCEPTION_IN_IRAM

		/* Not well tested.
		@@ -429,7 +428,9 @@ common_exception_return:
		/* Jump if we are returning from kernel exceptions. */

		l32i a3, a1, PT_PS
		_bbci.l a3, PS_UM_BIT, 4f
		GET_THREAD_INFO(a2, a1)
		l32i a4, a2, TI_FLAGS
		_bbci.l a3, PS_UM_BIT, 6f

		/* Specific to a user exception exit:
		* We need to check some flags for signal handling and rescheduling,
		@@ -438,9 +439,6 @@ common_exception_return:
		* Note that we don't disable interrupts here.
		*/

		GET_THREAD_INFO(a2,a1)
		l32i a4, a2, TI_FLAGS

		_bbsi.l a4, TIF_NEED_RESCHED, 3f
		_bbsi.l a4, TIF_NOTIFY_RESUME, 2f
		_bbci.l a4, TIF_SIGPENDING, 5f
		@@ -463,6 +461,19 @@ common_exception_return:
		callx4 a4
		j 1b

		#ifdef CONFIG_PREEMPT
		6:
		_bbci.l a4, TIF_NEED_RESCHED, 4f

		/* Check current_thread_info->preempt_count */

		l32i a4, a2, TI_PRE_COUNT
		bnez a4, 4f
		movi a4, preempt_schedule_irq
		callx4 a4
		j 1b
		#endif

		5:
		#ifdef CONFIG_DEBUG_TLB_SANITY
		l32i a4, a1, PT_DEPC
		@@ -470,6 +481,7 @@ common_exception_return:
		movi a4, check_tlb_sanity
		callx4 a4
		#endif
		6:
		4:
		#ifdef CONFIG_TRACE_IRQFLAGS
		l32i a4, a1, PT_DEPC
		@@ -573,29 +585,6 @@ user_exception_exit:

		kernel_exception_exit:

		#ifdef PREEMPTIBLE_KERNEL

		#ifdef CONFIG_PREEMPT

		/*
		* Note: We've just returned from a call4, so we have
		* at least 4 addt'l regs.
		*/

		/* Check current_thread_info->preempt_count */

		GET_THREAD_INFO(a2)
		l32i a3, a2, TI_PREEMPT
		bnez a3, 1f

		l32i a2, a2, TI_FLAGS

		1:

		#endif

		#endif

		/* Check if we have to do a movsp.
		*
		* We only have to do a movsp if the previous window-frame has