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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/powerpc/kernel/idle.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/powerpc/kernel/idle.c')
-rw-r--r--arch/powerpc/kernel/idle.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
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+/*
+ * 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).
+ * Subsequent 32-bit hacking by Tom Rini, Armin Kuster,
+ * Paul Mackerras and others.
+ *
+ * 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>
+ *
+ * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org>
+ *
+ * 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/sched.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/sysctl.h>
+#include <linux/tick.h>
+
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#include <asm/runlatch.h>
+#include <asm/smp.h>
+
+#ifdef CONFIG_HOTPLUG_CPU
+#define cpu_should_die() cpu_is_offline(smp_processor_id())
+#else
+#define cpu_should_die() 0
+#endif
+
+unsigned long cpuidle_disable = IDLE_NO_OVERRIDE;
+EXPORT_SYMBOL(cpuidle_disable);
+
+static int __init powersave_off(char *arg)
+{
+ ppc_md.power_save = NULL;
+ cpuidle_disable = IDLE_POWERSAVE_OFF;
+ return 0;
+}
+__setup("powersave=off", powersave_off);
+
+/*
+ * The body of the idle task.
+ */
+void cpu_idle(void)
+{
+ if (ppc_md.idle_loop)
+ ppc_md.idle_loop(); /* doesn't return */
+
+ set_thread_flag(TIF_POLLING_NRFLAG);
+ while (1) {
+ tick_nohz_idle_enter();
+ rcu_idle_enter();
+
+ while (!need_resched() && !cpu_should_die()) {
+ ppc64_runlatch_off();
+
+ if (ppc_md.power_save) {
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ /*
+ * smp_mb is so clearing of TIF_POLLING_NRFLAG
+ * is ordered w.r.t. need_resched() test.
+ */
+ smp_mb();
+ local_irq_disable();
+
+ /* Don't trace irqs off for idle */
+ stop_critical_timings();
+
+ /* check again after disabling irqs */
+ if (!need_resched() && !cpu_should_die())
+ ppc_md.power_save();
+
+ start_critical_timings();
+
+ /* Some power_save functions return with
+ * interrupts enabled, some don't.
+ */
+ if (irqs_disabled())
+ local_irq_enable();
+ set_thread_flag(TIF_POLLING_NRFLAG);
+
+ } else {
+ /*
+ * Go into low thread priority and possibly
+ * low power mode.
+ */
+ HMT_low();
+ HMT_very_low();
+ }
+ }
+
+ HMT_medium();
+ ppc64_runlatch_on();
+ rcu_idle_exit();
+ tick_nohz_idle_exit();
+ if (cpu_should_die()) {
+ sched_preempt_enable_no_resched();
+ cpu_die();
+ }
+ schedule_preempt_disabled();
+ }
+}
+
+static void do_nothing(void *unused)
+{
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs come out of the old
+ * idle loop and start using the new idle loop.
+ * Required while changing idle handler on SMP systems.
+ * Caller must have changed idle handler to the new value before the call.
+ * This window may be larger on shared systems.
+ */
+void cpu_idle_wait(void)
+{
+ smp_mb();
+ /* kick all the CPUs so that they exit out of pm_idle */
+ smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
+
+int powersave_nap;
+
+#ifdef CONFIG_SYSCTL
+/*
+ * Register the sysctl to set/clear powersave_nap.
+ */
+static ctl_table powersave_nap_ctl_table[]={
+ {
+ .procname = "powersave-nap",
+ .data = &powersave_nap,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
+ {}
+};
+static ctl_table powersave_nap_sysctl_root[] = {
+ {
+ .procname = "kernel",
+ .mode = 0555,
+ .child = powersave_nap_ctl_table,
+ },
+ {}
+};
+
+static int __init
+register_powersave_nap_sysctl(void)
+{
+ register_sysctl_table(powersave_nap_sysctl_root);
+
+ return 0;
+}
+__initcall(register_powersave_nap_sysctl);
+#endif