1 files changed, 119 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
new file mode 100644
index 0000000000..b1c0418b25
--- /dev/null
+++ b/arch/powerpc/kernel/idle.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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>
+ */
+
+#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>
+
+
+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 1;
+}
+__setup("powersave=off", powersave_off);
+
+void arch_cpu_idle(void)
+{
+	ppc64_runlatch_off();
+
+	if (ppc_md.power_save) {
+		ppc_md.power_save();
+		/*
+		 * Some power_save functions return with
+		 * interrupts enabled, some don't.
+		 */
+		if (!irqs_disabled())
+			raw_local_irq_disable();
+	} else {
+		/*
+		 * Go into low thread priority and possibly
+		 * low power mode.
+		 */
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	ppc64_runlatch_on();
+}
+
+int powersave_nap;
+
+#ifdef CONFIG_PPC_970_NAP
+void power4_idle(void)
+{
+	if (!cpu_has_feature(CPU_FTR_CAN_NAP))
+		return;
+
+	if (!powersave_nap)
+		return;
+
+	if (!prep_irq_for_idle())
+		return;
+
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		asm volatile(PPC_DSSALL " ; sync" ::: "memory");
+
+	power4_idle_nap();
+
+	/*
+	 * power4_idle_nap returns with interrupts enabled (soft and hard).
+	 * to our caller with interrupts enabled (soft and hard). Our caller
+	 * can cope with either interrupts disabled or enabled upon return.
+	 */
+}
+#endif
+
+#ifdef CONFIG_SYSCTL
+/*
+ * Register the sysctl to set/clear powersave_nap.
+ */
+static struct ctl_table powersave_nap_ctl_table[] = {
+	{
+		.procname	= "powersave-nap",
+		.data		= &powersave_nap,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+	},
+	{}
+};
+
+static int __init
+register_powersave_nap_sysctl(void)
+{
+	register_sysctl("kernel", powersave_nap_ctl_table);
+
+	return 0;
+}
+__initcall(register_powersave_nap_sysctl);
+#endif