powerpc: Unify the 32 and 64 bit idle loops
This unifies the 32-bit (ARCH=ppc and ARCH=powerpc) and 64-bit idle
loops. It brings over the concept of having a ppc_md.power_save
function from 32-bit to ARCH=powerpc, which lets us get rid of
native_idle(). With this we will also be able to simplify the idle
handling for pSeries and cell.
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
new file mode 100644
index 0000000..e9f321d
--- /dev/null
+++ b/arch/powerpc/kernel/idle.c
@@ -0,0 +1,122 @@
+/*
+ * 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) {
+ ppc64_runlatch_off();
+
+ while (!need_resched() && !cpu_should_die()) {
+ 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
