This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / powerpc / kernel / idle.c

diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
new file mode 100644 (file)
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+++ 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/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/cpu.h>
+#include <linux/sysctl.h>
+
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#include <asm/smp.h>
+
+#ifdef CONFIG_HOTPLUG_CPU
+#define cpu_should_die()       (cpu_is_offline(smp_processor_id()) && \
+                                system_state == SYSTEM_RUNNING)
+#else
+#define cpu_should_die()       0
+#endif
+
+/*
+ * 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) {
+               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();
+
+                               /* check again after disabling irqs */
+                               if (!need_resched() && !cpu_should_die())
+                                       ppc_md.power_save();
+
+                               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();
+               if (cpu_should_die())
+                       cpu_die();
+               preempt_enable_no_resched();
+               schedule();
+               preempt_disable();
+       }
+}
+
+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