1 files changed, 162 insertions, 0 deletions
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
new file mode 100644
index 00000000..ee226e20
--- /dev/null
+++ b/arch/sh/kernel/idle.c
@@ -0,0 +1,162 @@
+/*
+ * The idle loop for all SuperH platforms.
+ *
+ *  Copyright (C) 2002 - 2009  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/pm.h>
+#include <linux/tick.h>
+#include <linux/preempt.h>
+#include <linux/thread_info.h>
+#include <linux/irqflags.h>
+#include <linux/smp.h>
+#include <linux/cpuidle.h>
+#include <linux/atomic.h>
+#include <asm/pgalloc.h>
+#include <asm/smp.h>
+#include <asm/bl_bit.h>
+
+void (*pm_idle)(void);
+
+static int hlt_counter;
+
+static int __init nohlt_setup(char *__unused)
+{
+	hlt_counter = 1;
+	return 1;
+}
+__setup("nohlt", nohlt_setup);
+
+static int __init hlt_setup(char *__unused)
+{
+	hlt_counter = 0;
+	return 1;
+}
+__setup("hlt", hlt_setup);
+
+static inline int hlt_works(void)
+{
+	return !hlt_counter;
+}
+
+/*
+ * On SMP it's slightly faster (but much more power-consuming!)
+ * to poll the ->work.need_resched flag instead of waiting for the
+ * cross-CPU IPI to arrive. Use this option with caution.
+ */
+static void poll_idle(void)
+{
+	local_irq_enable();
+	while (!need_resched())
+		cpu_relax();
+}
+
+void default_idle(void)
+{
+	if (hlt_works()) {
+		clear_thread_flag(TIF_POLLING_NRFLAG);
+		smp_mb__after_clear_bit();
+
+		set_bl_bit();
+		if (!need_resched()) {
+			local_irq_enable();
+			cpu_sleep();
+		} else
+			local_irq_enable();
+
+		set_thread_flag(TIF_POLLING_NRFLAG);
+		clear_bl_bit();
+	} else
+		poll_idle();
+}
+
+/*
+ * The idle thread. There's no useful work to be done, so just try to conserve
+ * power and have a low exit latency (ie sit in a loop waiting for somebody to
+ * say that they'd like to reschedule)
+ */
+void cpu_idle(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	/* endless idle loop with no priority at all */
+	while (1) {
+		tick_nohz_idle_enter();
+		rcu_idle_enter();
+
+		while (!need_resched()) {
+			check_pgt_cache();
+			rmb();
+
+			if (cpu_is_offline(cpu))
+				play_dead();
+
+			local_irq_disable();
+			/* Don't trace irqs off for idle */
+			stop_critical_timings();
+			if (cpuidle_idle_call())
+				pm_idle();
+			/*
+			 * Sanity check to ensure that pm_idle() returns
+			 * with IRQs enabled
+			 */
+			WARN_ON(irqs_disabled());
+			start_critical_timings();
+		}
+
+		rcu_idle_exit();
+		tick_nohz_idle_exit();
+		schedule_preempt_disabled();
+	}
+}
+
+void __init select_idle_routine(void)
+{
+	/*
+	 * If a platform has set its own idle routine, leave it alone.
+	 */
+	if (pm_idle)
+		return;
+
+	if (hlt_works())
+		pm_idle = default_idle;
+	else
+		pm_idle = poll_idle;
+}
+
+static void do_nothing(void *unused)
+{
+}
+
+void stop_this_cpu(void *unused)
+{
+	local_irq_disable();
+	set_cpu_online(smp_processor_id(), false);
+
+	for (;;)
+		cpu_sleep();
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
+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);