[deliverable/linux.git] / arch / ppc64 / kernel / idle.c

/*
 * Idle daemon for PowerPC.  Idle daemon will handle any action
 * that needs to be taken when the system becomes idle.
 *
 * Originally Written by Cort Dougan (cort@cs.nmt.edu)
 *
 * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
 *
 * Additional shared processor, SMT, and firmware support
 *    Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <linux/smp.h>

#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
#include <asm/time.h>
#include <asm/iSeries/HvCall.h>
#include <asm/iSeries/ItLpQueue.h>
#include <asm/plpar_wrappers.h>
#include <asm/systemcfg.h>
#include <asm/machdep.h>

extern void power4_idle(void);

int default_idle(void)
{
	long oldval;
	unsigned int cpu = smp_processor_id();

	while (1) {
		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);

		if (!oldval) {
			set_thread_flag(TIF_POLLING_NRFLAG);

			while (!need_resched() && !cpu_is_offline(cpu)) {
				barrier();
				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();
			}

			HMT_medium();
			clear_thread_flag(TIF_POLLING_NRFLAG);
		} else {
			set_need_resched();
		}

		schedule();
		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}

	return 0;
}

int native_idle(void)
{
	while(1) {
		/* check CPU type here */
		if (!need_resched())
			power4_idle();
		if (need_resched())
			schedule();

		if (cpu_is_offline(raw_smp_processor_id()) &&
		    system_state == SYSTEM_RUNNING)
			cpu_die();
	}
	return 0;
}

void cpu_idle(void)
{
	BUG_ON(NULL == ppc_md.idle_loop);
	ppc_md.idle_loop();
}

int powersave_nap;

#ifdef CONFIG_SYSCTL
/*
 * Register the sysctl to set/clear powersave_nap.
 */
static ctl_table powersave_nap_ctl_table[]={
	{
		.ctl_name	= KERN_PPC_POWERSAVE_NAP,
		.procname	= "powersave-nap",
		.data		= &powersave_nap,
		.maxlen		= sizeof(int),
		.mode		= 0644,
		.proc_handler	= &proc_dointvec,
	},
	{ 0, },
};
static ctl_table powersave_nap_sysctl_root[] = {
	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
 	{ 0,},
};

static int __init
register_powersave_nap_sysctl(void)
{
	register_sysctl_table(powersave_nap_sysctl_root, 0);

	return 0;
}
__initcall(register_powersave_nap_sysctl);
#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Idle daemon for PowerPC. Idle daemon will handle any action
	3	* that needs to be taken when the system becomes idle.
	4	*
	5	* Originally Written by Cort Dougan (cort@cs.nmt.edu)
	6	*
	7	* iSeries supported added by Mike Corrigan <mikejc@us.ibm.com>
	8	*
	9	* Additional shared processor, SMT, and firmware support
	10	* Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com>
	11	*
	12	* This program is free software; you can redistribute it and/or
	13	* modify it under the terms of the GNU General Public License
	14	* as published by the Free Software Foundation; either version
	15	* 2 of the License, or (at your option) any later version.
	16	*/
	17
	18	#include <linux/config.h>
	19	#include <linux/sched.h>
	20	#include <linux/kernel.h>
	21	#include <linux/smp.h>
	22	#include <linux/cpu.h>
	23	#include <linux/module.h>
	24	#include <linux/sysctl.h>
	25	#include <linux/smp.h>
	26
	27	#include <asm/system.h>
	28	#include <asm/processor.h>
	29	#include <asm/mmu.h>
	30	#include <asm/cputable.h>
	31	#include <asm/time.h>
	32	#include <asm/iSeries/HvCall.h>
	33	#include <asm/iSeries/ItLpQueue.h>
	34	#include <asm/plpar_wrappers.h>
	35	#include <asm/systemcfg.h>
fd899c0c	36	#include <asm/machdep.h>
1da177e4 LT	37
	38	extern void power4_idle(void);
	39
fd899c0c	40	int default_idle(void)
1da177e4 LT	41	{
	42	long oldval;
	43	unsigned int cpu = smp_processor_id();
	44
	45	while (1) {
	46	oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
	47
	48	if (!oldval) {
	49	set_thread_flag(TIF_POLLING_NRFLAG);
	50
	51	while (!need_resched() && !cpu_is_offline(cpu)) {
	52	barrier();
	53	/*
	54	* Go into low thread priority and possibly
	55	* low power mode.
	56	*/
	57	HMT_low();
	58	HMT_very_low();
	59	}
	60
	61	HMT_medium();
	62	clear_thread_flag(TIF_POLLING_NRFLAG);
	63	} else {
	64	set_need_resched();
	65	}
	66
	67	schedule();
	68	if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
	69	cpu_die();
	70	}
	71
	72	return 0;
	73	}
	74
fd899c0c	75	int native_idle(void)
1da177e4 LT	76	{
	77	while(1) {
	78	/* check CPU type here */
	79	if (!need_resched())
	80	power4_idle();
	81	if (need_resched())
	82	schedule();
	83
39c715b7	84	if (cpu_is_offline(raw_smp_processor_id()) &&
1da177e4 LT	85	system_state == SYSTEM_RUNNING)
	86	cpu_die();
	87	}
	88	return 0;
	89	}
	90
1da177e4 LT	91	void cpu_idle(void)
1da177e4 LT	92	{
fd899c0c ME	93	BUG_ON(NULL == ppc_md.idle_loop);
fd899c0c ME	94	ppc_md.idle_loop();
1da177e4 LT	95	}
	96
	97	int powersave_nap;
	98
	99	#ifdef CONFIG_SYSCTL
	100	/*
	101	* Register the sysctl to set/clear powersave_nap.
	102	*/
	103	static ctl_table powersave_nap_ctl_table[]={
	104	{
	105	.ctl_name = KERN_PPC_POWERSAVE_NAP,
	106	.procname = "powersave-nap",
	107	.data = &powersave_nap,
	108	.maxlen = sizeof(int),
	109	.mode = 0644,
	110	.proc_handler = &proc_dointvec,
	111	},
	112	{ 0, },
	113	};
	114	static ctl_table powersave_nap_sysctl_root[] = {
	115	{ 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
	116	{ 0,},
	117	};
	118
	119	static int __init
	120	register_powersave_nap_sysctl(void)
	121	{
	122	register_sysctl_table(powersave_nap_sysctl_root, 0);
	123
	124	return 0;
	125	}
	126	__initcall(register_powersave_nap_sysctl);
	127	#endif