arch: arm: aarch32: Introduce z_arm_on_enter_cpu_idle() hook (22b17e49) · Commits · Wenxi XU / zephyr

arch/arm/Kconfig

+8 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,14 @@ config CODE_DATA_RELOCATION_SRAM
		config is used to create an MPU entry for the SRAM space used for code
		relocation.

		config ARM_ON_ENTER_CPU_IDLE_HOOK
		bool
		help
		Enables a hook (z_arm_on_enter_cpu_idle()) that is called when
		the CPU is made idle (by k_cpu_idle() or k_cpu_atomic_idle()).
		If needed, this hook can be used to prevent the CPU from actually
		entering sleep by skipping the WFE/WFI instruction.

		rsource "core/aarch32/Kconfig"
		rsource "core/aarch32/Kconfig.vfp"

+30 −9

Original line number	Diff line number	Diff line
		@@ -48,6 +48,33 @@ SECTION_FUNC(TEXT, z_arm_cpu_idle_init)
		#endif
		bx lr

		.macro _sleep_if_allowed wait_instruction
		#if defined(CONFIG_ARM_ON_ENTER_CPU_IDLE_HOOK)
		push {r0, lr}
		bl z_arm_on_enter_cpu_idle
		/* Skip the wait instruction if on_enter_cpu_idle() returns false. */
		cmp r0, #0
		beq _skip_\@
		#endif /* CONFIG_ARM_ON_ENTER_CPU_IDLE_HOOK */

		/*
		* Wait for all memory transactions to complete before entering low
		* power state.
		*/
		dsb
		\wait_instruction

		#if defined(CONFIG_ARM_ON_ENTER_CPU_IDLE_HOOK)
		_skip_\@:
		#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
		pop {r0, r1}
		mov lr, r1
		#else
		pop {r0, lr}
		#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
		#endif /* CONFIG_ARM_ON_ENTER_CPU_IDLE_HOOK */
		.endm

		SECTION_FUNC(TEXT, arch_cpu_idle)
		#ifdef CONFIG_TRACING
		push {r0, lr}
		@@ -89,14 +116,8 @@ SECTION_FUNC(TEXT, arch_cpu_idle)
		*/
		#endif /* CONFIG_ARMV7_M_ARMV8_M_MAINLINE */

		/*
		* Wait for all memory transactions to complete before entering low
		* power state.
		*/
		dsb

		/* Enter low power state */
		wfi
		_sleep_if_allowed wfi

		/*
		* Clear PRIMASK and flush instruction buffer to immediately service
		@@ -139,7 +160,7 @@ SECTION_FUNC(TEXT, arch_cpu_atomic_idle)
		/* No BASEPRI, call wfe directly
		* (SEVONPEND is set in z_arm_cpu_idle_init())
		*/
		wfe
		_sleep_if_allowed wfe

		cmp r0, #0
		bne _irq_disabled
		@@ -153,7 +174,7 @@ _irq_disabled:
		/* unlock BASEPRI so wfe gets interrupted by incoming interrupts */
		msr BASEPRI, r1

		wfe
		_sleep_if_allowed wfe

		msr BASEPRI, r0
		cpsie i

+9 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,15 @@ static ALWAYS_INLINE void arch_nop(void)
		extern bool z_arm_thread_is_in_user_mode(void);
		#endif

		#if defined(CONFIG_ARM_ON_ENTER_CPU_IDLE_HOOK)
		/* Prototype of a hook that can be enabled to be called every time the CPU is
		* made idle (the calls will be done from k_cpu_idle() and k_cpu_atomic_idle()).
		* If this hook returns false, the CPU is prevented from entering the actual
		* sleep (the WFE/WFI instruction is skipped).
		*/
		bool z_arm_on_enter_cpu_idle(void);
		#endif

		#endif

		#ifdef __cplusplus