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Commit f7b861b7 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

arm: Use generic idle loop 



Use the generic idle loop and replace enable/disable_hlt with the
respective core functions.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarCc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Tested-by: Kevin Hilman <khilman@linaro.org> # OMAP
Link: http://lkml.kernel.org/r/20130321215233.826238797@linutronix.de
parent a123322d

arch/arm/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ config ARM 
	select GENERIC_IRQ_SHOW

	select GENERIC_PCI_IOMAP

	select GENERIC_SMP_IDLE_THREAD

	select GENERIC_IDLE_LOOP

	select GENERIC_IDLE_POLL_SETUP

	select GENERIC_STRNCPY_FROM_USER

	select GENERIC_STRNLEN_USER

	select HARDIRQS_SW_RESEND

arch/arm/include/asm/system_misc.h

+0 −3
Original line number Diff line number Diff line
@@ -21,9 +21,6 @@ extern void (*arm_pm_idle)(void); 


extern unsigned int user_debug;



extern void disable_hlt(void);

extern void enable_hlt(void);



#endif /* !__ASSEMBLY__ */



#endif /* __ASM_ARM_SYSTEM_MISC_H */

arch/arm/kernel/process.c

+26 −70
Original line number Diff line number Diff line
@@ -57,34 +57,6 @@ static const char *isa_modes[] = { 
  "ARM" , "Thumb" , "Jazelle", "ThumbEE"

};



static volatile int hlt_counter;



void disable_hlt(void)

{

	hlt_counter++;

}



void enable_hlt(void)

{

	hlt_counter--;

	BUG_ON(hlt_counter < 0);

}



static int __init nohlt_setup(char *__unused)

{

	hlt_counter = 1;

	return 1;

}



static int __init hlt_setup(char *__unused)

{

	hlt_counter = 0;

	return 1;

}



__setup("nohlt", nohlt_setup);

__setup("hlt", hlt_setup);



extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);

typedef void (*phys_reset_t)(unsigned long);
@@ -168,54 +140,38 @@ static void default_idle(void) 
	local_irq_enable();

}



/*

 * The idle thread.

 * We always respect 'hlt_counter' to prevent low power idle.

 */

void cpu_idle(void)

void arch_cpu_idle_prepare(void)

{

	local_fiq_enable();

}



	/* endless idle loop with no priority at all */

	while (1) {

		tick_nohz_idle_enter();

		rcu_idle_enter();

void arch_cpu_idle_enter(void)

{

	ledtrig_cpu(CPU_LED_IDLE_START);

		while (!need_resched()) {

#ifdef CONFIG_PL310_ERRATA_769419

	wmb();

#endif

}



void arch_cpu_idle_exit(void)

{

	ledtrig_cpu(CPU_LED_IDLE_END);

}



#ifdef CONFIG_HOTPLUG_CPU

			if (cpu_is_offline(smp_processor_id()))

void arch_cpu_idle_dead(void)

{

	cpu_die();

}

#endif



/*

			 * We need to disable interrupts here

			 * to ensure we don't miss a wakeup call.

 * Called from the core idle loop.

 */

			local_irq_disable();

#ifdef CONFIG_PL310_ERRATA_769419

			wmb();

#endif

			if (hlt_counter) {

				local_irq_enable();

				cpu_relax();

			} else if (!need_resched()) {

				stop_critical_timings();

void arch_cpu_idle(void)

{

	if (cpuidle_idle_call())

		default_idle();

				start_critical_timings();

				/*

				 * default_idle functions must always

				 * return with IRQs enabled.

				 */

				WARN_ON(irqs_disabled());

			} else

				local_irq_enable();

		}

		ledtrig_cpu(CPU_LED_IDLE_END);

		rcu_idle_exit();

		tick_nohz_idle_exit();

		schedule_preempt_disabled();

	}

}



static char reboot_mode = 'h';

arch/arm/kernel/smp.c

+1 −1
Original line number Diff line number Diff line
@@ -336,7 +336,7 @@ asmlinkage void __cpuinit secondary_start_kernel(void) 
	/*

	 * OK, it's off to the idle thread for us

	 */

	cpu_idle();

	cpu_startup_entry(CPUHP_ONLINE);

}



void __init smp_cpus_done(unsigned int max_cpus)

arch/arm/mach-gemini/idle.c

+3 −1
Original line number Diff line number Diff line
@@ -13,9 +13,11 @@ static void gemini_idle(void) 
	 * will never wakeup... Acctualy it is not very good to enable

	 * interrupts first since scheduler can miss a tick, but there is

	 * no other way around this. Platforms that needs it for power saving

	 * should call enable_hlt() in init code, since by default it is

	 * should enable it in init code, since by default it is

	 * disabled.

	 */



	/* FIXME: Enabling interrupts here is racy! */

	local_irq_enable();

	cpu_do_idle();

}