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-rw-r--r--arch/powerpc/kernel/idle.c128
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diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
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+// 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_enable();
+ } else {
+ raw_local_irq_enable();
+ /*
+ * 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 struct 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