mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-29 07:04:10 +08:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
381 lines
8.2 KiB
C
381 lines
8.2 KiB
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>
|
|
|
|
extern void power4_idle(void);
|
|
|
|
static int (*idle_loop)(void);
|
|
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
static unsigned long maxYieldTime = 0;
|
|
static unsigned long minYieldTime = 0xffffffffffffffffUL;
|
|
|
|
static void yield_shared_processor(void)
|
|
{
|
|
unsigned long tb;
|
|
unsigned long yieldTime;
|
|
|
|
HvCall_setEnabledInterrupts(HvCall_MaskIPI |
|
|
HvCall_MaskLpEvent |
|
|
HvCall_MaskLpProd |
|
|
HvCall_MaskTimeout);
|
|
|
|
tb = get_tb();
|
|
/* Compute future tb value when yield should expire */
|
|
HvCall_yieldProcessor(HvCall_YieldTimed, tb+tb_ticks_per_jiffy);
|
|
|
|
yieldTime = get_tb() - tb;
|
|
if (yieldTime > maxYieldTime)
|
|
maxYieldTime = yieldTime;
|
|
|
|
if (yieldTime < minYieldTime)
|
|
minYieldTime = yieldTime;
|
|
|
|
/*
|
|
* The decrementer stops during the yield. Force a fake decrementer
|
|
* here and let the timer_interrupt code sort out the actual time.
|
|
*/
|
|
get_paca()->lppaca.int_dword.fields.decr_int = 1;
|
|
process_iSeries_events();
|
|
}
|
|
|
|
static int iSeries_idle(void)
|
|
{
|
|
struct paca_struct *lpaca;
|
|
long oldval;
|
|
unsigned long CTRL;
|
|
|
|
/* ensure iSeries run light will be out when idle */
|
|
clear_thread_flag(TIF_RUN_LIGHT);
|
|
CTRL = mfspr(CTRLF);
|
|
CTRL &= ~RUNLATCH;
|
|
mtspr(CTRLT, CTRL);
|
|
|
|
lpaca = get_paca();
|
|
|
|
while (1) {
|
|
if (lpaca->lppaca.shared_proc) {
|
|
if (ItLpQueue_isLpIntPending(lpaca->lpqueue_ptr))
|
|
process_iSeries_events();
|
|
if (!need_resched())
|
|
yield_shared_processor();
|
|
} else {
|
|
oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
|
|
|
|
if (!oldval) {
|
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
|
|
|
while (!need_resched()) {
|
|
HMT_medium();
|
|
if (ItLpQueue_isLpIntPending(lpaca->lpqueue_ptr))
|
|
process_iSeries_events();
|
|
HMT_low();
|
|
}
|
|
|
|
HMT_medium();
|
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
|
} else {
|
|
set_need_resched();
|
|
}
|
|
}
|
|
|
|
schedule();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#else
|
|
|
|
static 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;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
|
|
DECLARE_PER_CPU(unsigned long, smt_snooze_delay);
|
|
|
|
int dedicated_idle(void)
|
|
{
|
|
long oldval;
|
|
struct paca_struct *lpaca = get_paca(), *ppaca;
|
|
unsigned long start_snooze;
|
|
unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);
|
|
unsigned int cpu = smp_processor_id();
|
|
|
|
ppaca = &paca[cpu ^ 1];
|
|
|
|
while (1) {
|
|
/*
|
|
* Indicate to the HV that we are idle. Now would be
|
|
* a good time to find other work to dispatch.
|
|
*/
|
|
lpaca->lppaca.idle = 1;
|
|
|
|
oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
|
|
if (!oldval) {
|
|
set_thread_flag(TIF_POLLING_NRFLAG);
|
|
start_snooze = __get_tb() +
|
|
*smt_snooze_delay * tb_ticks_per_usec;
|
|
while (!need_resched() && !cpu_is_offline(cpu)) {
|
|
/*
|
|
* Go into low thread priority and possibly
|
|
* low power mode.
|
|
*/
|
|
HMT_low();
|
|
HMT_very_low();
|
|
|
|
if (*smt_snooze_delay == 0 ||
|
|
__get_tb() < start_snooze)
|
|
continue;
|
|
|
|
HMT_medium();
|
|
|
|
if (!(ppaca->lppaca.idle)) {
|
|
local_irq_disable();
|
|
|
|
/*
|
|
* We are about to sleep the thread
|
|
* and so wont be polling any
|
|
* more.
|
|
*/
|
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
|
|
|
/*
|
|
* SMT dynamic mode. Cede will result
|
|
* in this thread going dormant, if the
|
|
* partner thread is still doing work.
|
|
* Thread wakes up if partner goes idle,
|
|
* an interrupt is presented, or a prod
|
|
* occurs. Returning from the cede
|
|
* enables external interrupts.
|
|
*/
|
|
if (!need_resched())
|
|
cede_processor();
|
|
else
|
|
local_irq_enable();
|
|
} else {
|
|
/*
|
|
* Give the HV an opportunity at the
|
|
* processor, since we are not doing
|
|
* any work.
|
|
*/
|
|
poll_pending();
|
|
}
|
|
}
|
|
|
|
clear_thread_flag(TIF_POLLING_NRFLAG);
|
|
} else {
|
|
set_need_resched();
|
|
}
|
|
|
|
HMT_medium();
|
|
lpaca->lppaca.idle = 0;
|
|
schedule();
|
|
if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
|
|
cpu_die();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int shared_idle(void)
|
|
{
|
|
struct paca_struct *lpaca = get_paca();
|
|
unsigned int cpu = smp_processor_id();
|
|
|
|
while (1) {
|
|
/*
|
|
* Indicate to the HV that we are idle. Now would be
|
|
* a good time to find other work to dispatch.
|
|
*/
|
|
lpaca->lppaca.idle = 1;
|
|
|
|
while (!need_resched() && !cpu_is_offline(cpu)) {
|
|
local_irq_disable();
|
|
|
|
/*
|
|
* Yield the processor to the hypervisor. We return if
|
|
* an external interrupt occurs (which are driven prior
|
|
* to returning here) or if a prod occurs from another
|
|
* processor. When returning here, external interrupts
|
|
* are enabled.
|
|
*
|
|
* Check need_resched() again with interrupts disabled
|
|
* to avoid a race.
|
|
*/
|
|
if (!need_resched())
|
|
cede_processor();
|
|
else
|
|
local_irq_enable();
|
|
}
|
|
|
|
HMT_medium();
|
|
lpaca->lppaca.idle = 0;
|
|
schedule();
|
|
if (cpu_is_offline(smp_processor_id()) &&
|
|
system_state == SYSTEM_RUNNING)
|
|
cpu_die();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_PSERIES */
|
|
|
|
static int native_idle(void)
|
|
{
|
|
while(1) {
|
|
/* check CPU type here */
|
|
if (!need_resched())
|
|
power4_idle();
|
|
if (need_resched())
|
|
schedule();
|
|
|
|
if (cpu_is_offline(_smp_processor_id()) &&
|
|
system_state == SYSTEM_RUNNING)
|
|
cpu_die();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_ISERIES */
|
|
|
|
void cpu_idle(void)
|
|
{
|
|
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
|
|
|
|
int idle_setup(void)
|
|
{
|
|
/*
|
|
* Move that junk to each platform specific file, eventually define
|
|
* a pSeries_idle for shared processor stuff
|
|
*/
|
|
#ifdef CONFIG_PPC_ISERIES
|
|
idle_loop = iSeries_idle;
|
|
return 1;
|
|
#else
|
|
idle_loop = default_idle;
|
|
#endif
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
if (systemcfg->platform & PLATFORM_PSERIES) {
|
|
if (cur_cpu_spec->firmware_features & FW_FEATURE_SPLPAR) {
|
|
if (get_paca()->lppaca.shared_proc) {
|
|
printk(KERN_INFO "Using shared processor idle loop\n");
|
|
idle_loop = shared_idle;
|
|
} else {
|
|
printk(KERN_INFO "Using dedicated idle loop\n");
|
|
idle_loop = dedicated_idle;
|
|
}
|
|
} else {
|
|
printk(KERN_INFO "Using default idle loop\n");
|
|
idle_loop = default_idle;
|
|
}
|
|
}
|
|
#endif /* CONFIG_PPC_PSERIES */
|
|
#ifndef CONFIG_PPC_ISERIES
|
|
if (systemcfg->platform == PLATFORM_POWERMAC ||
|
|
systemcfg->platform == PLATFORM_MAPLE) {
|
|
printk(KERN_INFO "Using native/NAP idle loop\n");
|
|
idle_loop = native_idle;
|
|
}
|
|
#endif /* CONFIG_PPC_ISERIES */
|
|
|
|
return 1;
|
|
}
|