| 1 | |
| 2 | |
| 3 | * Idle daemon for PowerPC. Idle daemon will handle any action
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| 4 | * that needs to be taken when the system becomes idle.
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| 5 | *
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| 6 | * Originally written by Cort Dougan ([email protected]).
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| 7 | * Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
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| 8 | * Paul Mackerras and others.
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| 9 | *
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| 10 | * iSeries supported added by Mike Corrigan <[email protected]>
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| 11 | *
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| 12 | * Additional shared processor, SMT, and firmware support
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| 13 | * Copyright (c) 2003 Dave Engebretsen <[email protected]>
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| 14 | *
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| 15 | * 32-bit and 64-bit versions merged by Paul Mackerras <[email protected]>
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| 16 |
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| 17 |
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| 18 | #include <linux/sched.h>
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| 19 | #include <linux/kernel.h>
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| 20 | #include <linux/smp.h>
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| 21 | #include <linux/cpu.h>
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| 22 | #include <linux/sysctl.h>
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| 23 | #include <linux/tick.h>
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| 24 |
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| 25 | #include <asm/processor.h>
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| 26 | #include <asm/cputable.h>
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| 27 | #include <asm/time.h>
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| 28 | #include <asm/machdep.h>
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| 29 | #include <asm/runlatch.h>
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| 30 | #include <asm/smp.h>
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| 31 |
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| 32 |
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| 33 | unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
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| 34 | EXPORT_SYMBOL(cpuidle_disable);
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| 35 |
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| 36 | static int __init powersave_off(char *arg)
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| 37 | {
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| 38 | ppc_md.power_save = NULL;
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| 39 | cpuidle_disable = IDLE_POWERSAVE_OFF;
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| 40 | return 1;
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| 41 | }
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| 42 | __setup("powersave=off", powersave_off);
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| 43 |
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| 44 | void arch_cpu_idle(void)
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| 45 | {
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| 46 | ppc64_runlatch_off();
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| 47 |
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| 48 | if (ppc_md.power_save) {
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| 49 | ppc_md.power_save();
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| 50 | |
| 51 | * Some power_save functions return with
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| 52 | * interrupts enabled, some don't.
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| 53 |
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| 54 | if (!irqs_disabled())
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| 55 | raw_local_irq_disable();
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| 56 | } else {
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| 57 | |
| 58 | * Go into low thread priority and possibly
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| 59 | * low power mode.
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| 60 |
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| 61 | HMT_low();
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| 62 | HMT_very_low();
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| 63 | }
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| 64 |
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| 65 | HMT_medium();
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| 66 | ppc64_runlatch_on();
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| 67 | }
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| 68 |
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| 69 | int powersave_nap;
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| 70 |
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| 71 | #ifdef CONFIG_PPC_970_NAP
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| 72 | void power4_idle(void)
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| 73 | {
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| 74 | if (!cpu_has_feature(CPU_FTR_CAN_NAP))
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| 75 | return;
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| 76 |
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| 77 | if (!powersave_nap)
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| 78 | return;
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| 79 |
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| 80 | if (!prep_irq_for_idle())
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| 81 | return;
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| 82 |
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| 83 | if (cpu_has_feature(CPU_FTR_ALTIVEC))
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| 84 | asm volatile(PPC_DSSALL " ; sync" ::: "memory");
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| 85 |
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| 86 | power4_idle_nap();
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| 87 |
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| 88 | |
| 89 | * power4_idle_nap returns with interrupts enabled (soft and hard).
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| 90 | * to our caller with interrupts enabled (soft and hard). Our caller
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| 91 | * can cope with either interrupts disabled or enabled upon return.
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| 92 |
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| 93 | }
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| 94 | #endif
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| 95 |
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| 96 | #ifdef CONFIG_SYSCTL
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| 97 | |
| 98 | * Register the sysctl to set/clear powersave_nap.
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| 99 |
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| 100 | static const struct ctl_table powersave_nap_ctl_table[] = {
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| 101 | {
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| 102 | .procname = "powersave-nap",
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| 103 | .data = &powersave_nap,
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| 104 | .maxlen = sizeof(int),
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| 105 | .mode = 0644,
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| 106 | .proc_handler = proc_dointvec,
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| 107 | },
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| 108 | };
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| 109 |
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| 110 | static int __init
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| 111 | register_powersave_nap_sysctl(void)
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| 112 | {
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| 113 | register_sysctl("kernel", powersave_nap_ctl_table);
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| 114 |
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| 115 | return 0;
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| 116 | }
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| 117 | __initcall(register_powersave_nap_sysctl);
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| 118 | #endif
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