ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/drivers/cpuidle/governors/ladder.c b/marvell/linux/drivers/cpuidle/governors/ladder.c
new file mode 100644
index 0000000..428eeb8
--- /dev/null
+++ b/marvell/linux/drivers/cpuidle/governors/ladder.c
@@ -0,0 +1,198 @@
+/*
+ * ladder.c - the residency ladder algorithm
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
+ *
+ * (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ * Shaohua Li <shaohua.li@intel.com>
+ * Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/jiffies.h>
+#include <linux/tick.h>
+
+#include <asm/io.h>
+#include <linux/uaccess.h>
+
+#define PROMOTION_COUNT 4
+#define DEMOTION_COUNT 1
+
+struct ladder_device_state {
+ struct {
+ u32 promotion_count;
+ u32 demotion_count;
+ u32 promotion_time;
+ u32 demotion_time;
+ } threshold;
+ struct {
+ int promotion_count;
+ int demotion_count;
+ } stats;
+};
+
+struct ladder_device {
+ struct ladder_device_state states[CPUIDLE_STATE_MAX];
+};
+
+static DEFINE_PER_CPU(struct ladder_device, ladder_devices);
+
+/**
+ * ladder_do_selection - prepares private data for a state change
+ * @ldev: the ladder device
+ * @old_idx: the current state index
+ * @new_idx: the new target state index
+ */
+static inline void ladder_do_selection(struct cpuidle_device *dev,
+ struct ladder_device *ldev,
+ int old_idx, int new_idx)
+{
+ ldev->states[old_idx].stats.promotion_count = 0;
+ ldev->states[old_idx].stats.demotion_count = 0;
+ dev->last_state_idx = new_idx;
+}
+
+/**
+ * ladder_select_state - selects the next state to enter
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ * @dummy: not used
+ */
+static int ladder_select_state(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev, bool *dummy)
+{
+ struct ladder_device *ldev = this_cpu_ptr(&ladder_devices);
+ struct ladder_device_state *last_state;
+ int last_residency, last_idx = dev->last_state_idx;
+ int first_idx = drv->states[0].flags & CPUIDLE_FLAG_POLLING ? 1 : 0;
+ int latency_req = cpuidle_governor_latency_req(dev->cpu);
+
+ /* Special case when user has set very strict latency requirement */
+ if (unlikely(latency_req == 0)) {
+ ladder_do_selection(dev, ldev, last_idx, 0);
+ return 0;
+ }
+
+ last_state = &ldev->states[last_idx];
+
+ last_residency = dev->last_residency - drv->states[last_idx].exit_latency;
+
+ /* consider promotion */
+ if (last_idx < drv->state_count - 1 &&
+ !drv->states[last_idx + 1].disabled &&
+ !dev->states_usage[last_idx + 1].disable &&
+ last_residency > last_state->threshold.promotion_time &&
+ drv->states[last_idx + 1].exit_latency <= latency_req) {
+ last_state->stats.promotion_count++;
+ last_state->stats.demotion_count = 0;
+ if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) {
+ ladder_do_selection(dev, ldev, last_idx, last_idx + 1);
+ return last_idx + 1;
+ }
+ }
+
+ /* consider demotion */
+ if (last_idx > first_idx &&
+ (drv->states[last_idx].disabled ||
+ dev->states_usage[last_idx].disable ||
+ drv->states[last_idx].exit_latency > latency_req)) {
+ int i;
+
+ for (i = last_idx - 1; i > first_idx; i--) {
+ if (drv->states[i].exit_latency <= latency_req)
+ break;
+ }
+ ladder_do_selection(dev, ldev, last_idx, i);
+ return i;
+ }
+
+ if (last_idx > first_idx &&
+ last_residency < last_state->threshold.demotion_time) {
+ last_state->stats.demotion_count++;
+ last_state->stats.promotion_count = 0;
+ if (last_state->stats.demotion_count >= last_state->threshold.demotion_count) {
+ ladder_do_selection(dev, ldev, last_idx, last_idx - 1);
+ return last_idx - 1;
+ }
+ }
+
+ /* otherwise remain at the current state */
+ return last_idx;
+}
+
+/**
+ * ladder_enable_device - setup for the governor
+ * @drv: cpuidle driver
+ * @dev: the CPU
+ */
+static int ladder_enable_device(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{
+ int i;
+ int first_idx = drv->states[0].flags & CPUIDLE_FLAG_POLLING ? 1 : 0;
+ struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu);
+ struct ladder_device_state *lstate;
+ struct cpuidle_state *state;
+
+ dev->last_state_idx = first_idx;
+
+ for (i = first_idx; i < drv->state_count; i++) {
+ state = &drv->states[i];
+ lstate = &ldev->states[i];
+
+ lstate->stats.promotion_count = 0;
+ lstate->stats.demotion_count = 0;
+
+ lstate->threshold.promotion_count = PROMOTION_COUNT;
+ lstate->threshold.demotion_count = DEMOTION_COUNT;
+
+ if (i < drv->state_count - 1)
+ lstate->threshold.promotion_time = state->exit_latency;
+ if (i > first_idx)
+ lstate->threshold.demotion_time = state->exit_latency;
+ }
+
+ return 0;
+}
+
+/**
+ * ladder_reflect - update the correct last_state_idx
+ * @dev: the CPU
+ * @index: the index of actual state entered
+ */
+static void ladder_reflect(struct cpuidle_device *dev, int index)
+{
+ if (index > 0)
+ dev->last_state_idx = index;
+}
+
+static struct cpuidle_governor ladder_governor = {
+ .name = "ladder",
+ .rating = 10,
+ .enable = ladder_enable_device,
+ .select = ladder_select_state,
+ .reflect = ladder_reflect,
+};
+
+/**
+ * init_ladder - initializes the governor
+ */
+static int __init init_ladder(void)
+{
+ /*
+ * When NO_HZ is disabled, or when booting with nohz=off, the ladder
+ * governor is better so give it a higher rating than the menu
+ * governor.
+ */
+ if (!tick_nohz_enabled)
+ ladder_governor.rating = 25;
+
+ return cpuidle_register_governor(&ladder_governor);
+}
+
+postcore_initcall(init_ladder);