1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/cpuidle/poll_state.c b/drivers/cpuidle/poll_state.c
new file mode 100644
index 000000000..36ff5a1d9
--- /dev/null
+++ b/drivers/cpuidle/poll_state.c
@@ -0,0 +1,56 @@
+/*
+ * poll_state.c - Polling idle state
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/cpuidle.h>
+#include <linux/sched.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/idle.h>
+
+#define POLL_IDLE_TIME_LIMIT	(TICK_NSEC / 16)
+#define POLL_IDLE_RELAX_COUNT	200
+
+static int __cpuidle poll_idle(struct cpuidle_device *dev,
+			       struct cpuidle_driver *drv, int index)
+{
+	u64 time_start = local_clock();
+
+	dev->poll_time_limit = false;
+
+	local_irq_enable();
+	if (!current_set_polling_and_test()) {
+		unsigned int loop_count = 0;
+
+		while (!need_resched()) {
+			cpu_relax();
+			if (loop_count++ < POLL_IDLE_RELAX_COUNT)
+				continue;
+
+			loop_count = 0;
+			if (local_clock() - time_start > POLL_IDLE_TIME_LIMIT) {
+				dev->poll_time_limit = true;
+				break;
+			}
+		}
+	}
+	current_clr_polling();
+
+	return index;
+}
+
+void cpuidle_poll_state_init(struct cpuidle_driver *drv)
+{
+	struct cpuidle_state *state = &drv->states[0];
+
+	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
+	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
+	state->exit_latency = 0;
+	state->target_residency = 0;
+	state->power_usage = -1;
+	state->enter = poll_idle;
+	state->disabled = false;
+	state->flags = CPUIDLE_FLAG_POLLING;
+}
+EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);