| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 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 | * Subsequent 32-bit hacking by Tom Rini, Armin Kuster, |
| 7 | * Paul Mackerras and others. |
| 8 | * |
| 9 | * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com> |
| 10 | * |
| 11 | * Additional shared processor, SMT, and firmware support |
| 12 | * Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com> |
| 13 | * |
| 14 | * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org> |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or |
| 17 | * modify it under the terms of the GNU General Public License |
| 18 | * as published by the Free Software Foundation; either version |
| 19 | * 2 of the License, or (at your option) any later version. |
| 20 | */ |
| 21 | |
| 22 | #include <linux/sched.h> |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/smp.h> |
| 25 | #include <linux/cpu.h> |
| 26 | #include <linux/sysctl.h> |
| 27 | #include <linux/tick.h> |
| 28 | |
| 29 | #include <asm/processor.h> |
| 30 | #include <asm/cputable.h> |
| 31 | #include <asm/time.h> |
| 32 | #include <asm/machdep.h> |
| 33 | #include <asm/runlatch.h> |
| 34 | #include <asm/smp.h> |
| 35 | |
| 36 | |
| 37 | unsigned long cpuidle_disable = IDLE_NO_OVERRIDE; |
| 38 | EXPORT_SYMBOL(cpuidle_disable); |
| 39 | |
| 40 | static int __init powersave_off(char *arg) |
| 41 | { |
| 42 | ppc_md.power_save = NULL; |
| 43 | cpuidle_disable = IDLE_POWERSAVE_OFF; |
| 44 | return 0; |
| 45 | } |
| 46 | __setup("powersave=off", powersave_off); |
| 47 | |
| 48 | #ifdef CONFIG_HOTPLUG_CPU |
| 49 | void arch_cpu_idle_dead(void) |
| 50 | { |
| 51 | sched_preempt_enable_no_resched(); |
| 52 | cpu_die(); |
| 53 | } |
| 54 | #endif |
| 55 | |
| 56 | void arch_cpu_idle(void) |
| 57 | { |
| 58 | ppc64_runlatch_off(); |
| 59 | |
| 60 | if (ppc_md.power_save) { |
| 61 | ppc_md.power_save(); |
| 62 | /* |
| 63 | * Some power_save functions return with |
| 64 | * interrupts enabled, some don't. |
| 65 | */ |
| 66 | if (irqs_disabled()) |
| 67 | local_irq_enable(); |
| 68 | } else { |
| 69 | local_irq_enable(); |
| 70 | /* |
| 71 | * Go into low thread priority and possibly |
| 72 | * low power mode. |
| 73 | */ |
| 74 | HMT_low(); |
| 75 | HMT_very_low(); |
| 76 | } |
| 77 | |
| 78 | HMT_medium(); |
| 79 | ppc64_runlatch_on(); |
| 80 | } |
| 81 | |
| 82 | int powersave_nap; |
| 83 | |
| 84 | #ifdef CONFIG_SYSCTL |
| 85 | /* |
| 86 | * Register the sysctl to set/clear powersave_nap. |
| 87 | */ |
| 88 | static struct ctl_table powersave_nap_ctl_table[] = { |
| 89 | { |
| 90 | .procname = "powersave-nap", |
| 91 | .data = &powersave_nap, |
| 92 | .maxlen = sizeof(int), |
| 93 | .mode = 0644, |
| 94 | .proc_handler = proc_dointvec, |
| 95 | }, |
| 96 | {} |
| 97 | }; |
| 98 | static struct ctl_table powersave_nap_sysctl_root[] = { |
| 99 | { |
| 100 | .procname = "kernel", |
| 101 | .mode = 0555, |
| 102 | .child = powersave_nap_ctl_table, |
| 103 | }, |
| 104 | {} |
| 105 | }; |
| 106 | |
| 107 | static int __init |
| 108 | register_powersave_nap_sysctl(void) |
| 109 | { |
| 110 | register_sysctl_table(powersave_nap_sysctl_root); |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | __initcall(register_powersave_nap_sysctl); |
| 115 | #endif |