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-rw-r--r--drivers/cpuidle/governors/Makefile6
-rw-r--r--drivers/cpuidle/governors/ladder.c166
-rw-r--r--drivers/cpuidle/governors/menu.c137
3 files changed, 309 insertions, 0 deletions
diff --git a/drivers/cpuidle/governors/Makefile b/drivers/cpuidle/governors/Makefile
new file mode 100644
index 000000000000..1b512722689f
--- /dev/null
+++ b/drivers/cpuidle/governors/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for cpuidle governors.
+#
+
+obj-$(CONFIG_CPU_IDLE_GOV_LADDER) += ladder.o
+obj-$(CONFIG_CPU_IDLE_GOV_MENU) += menu.o
diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c
new file mode 100644
index 000000000000..eb666ecae7c9
--- /dev/null
+++ b/drivers/cpuidle/governors/ladder.c
@@ -0,0 +1,166 @@
+/*
+ * 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/latency.h>
+#include <linux/moduleparam.h>
+#include <linux/jiffies.h>
+
+#include <asm/io.h>
+#include <asm/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];
+ int last_state_idx;
+};
+
+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 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;
+ ldev->last_state_idx = new_idx;
+}
+
+/**
+ * ladder_select_state - selects the next state to enter
+ * @dev: the CPU
+ */
+static int ladder_select_state(struct cpuidle_device *dev)
+{
+ struct ladder_device *ldev = &__get_cpu_var(ladder_devices);
+ struct ladder_device_state *last_state;
+ int last_residency, last_idx = ldev->last_state_idx;
+
+ if (unlikely(!ldev))
+ return 0;
+
+ last_state = &ldev->states[last_idx];
+
+ if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID)
+ last_residency = cpuidle_get_last_residency(dev) - dev->states[last_idx].exit_latency;
+ else
+ last_residency = last_state->threshold.promotion_time + 1;
+
+ /* consider promotion */
+ if (last_idx < dev->state_count - 1 &&
+ last_residency > last_state->threshold.promotion_time &&
+ dev->states[last_idx + 1].exit_latency <= system_latency_constraint()) {
+ 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(ldev, last_idx, last_idx + 1);
+ return last_idx + 1;
+ }
+ }
+
+ /* consider demotion */
+ if (last_idx > 0 &&
+ 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(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
+ * @dev: the CPU
+ */
+static int ladder_enable_device(struct cpuidle_device *dev)
+{
+ int i;
+ struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu);
+ struct ladder_device_state *lstate;
+ struct cpuidle_state *state;
+
+ ldev->last_state_idx = 0;
+
+ for (i = 0; i < dev->state_count; i++) {
+ state = &dev->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 < dev->state_count - 1)
+ lstate->threshold.promotion_time = state->exit_latency;
+ if (i > 0)
+ lstate->threshold.demotion_time = state->exit_latency;
+ }
+
+ return 0;
+}
+
+static struct cpuidle_governor ladder_governor = {
+ .name = "ladder",
+ .rating = 10,
+ .enable = ladder_enable_device,
+ .select = ladder_select_state,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_ladder - initializes the governor
+ */
+static int __init init_ladder(void)
+{
+ return cpuidle_register_governor(&ladder_governor);
+}
+
+/**
+ * exit_ladder - exits the governor
+ */
+static void __exit exit_ladder(void)
+{
+ cpuidle_unregister_governor(&ladder_governor);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_ladder);
+module_exit(exit_ladder);
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
new file mode 100644
index 000000000000..299d45c3bdd2
--- /dev/null
+++ b/drivers/cpuidle/governors/menu.c
@@ -0,0 +1,137 @@
+/*
+ * menu.c - the menu idle governor
+ *
+ * Copyright (C) 2006-2007 Adam Belay <abelay@novell.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#include <linux/latency.h>
+#include <linux/time.h>
+#include <linux/ktime.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+
+#define BREAK_FUZZ 4 /* 4 us */
+
+struct menu_device {
+ int last_state_idx;
+
+ unsigned int expected_us;
+ unsigned int predicted_us;
+ unsigned int last_measured_us;
+ unsigned int elapsed_us;
+};
+
+static DEFINE_PER_CPU(struct menu_device, menu_devices);
+
+/**
+ * menu_select - selects the next idle state to enter
+ * @dev: the CPU
+ */
+static int menu_select(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &__get_cpu_var(menu_devices);
+ int i;
+
+ /* determine the expected residency time */
+ data->expected_us =
+ (u32) ktime_to_ns(tick_nohz_get_sleep_length()) / 1000;
+
+ /* find the deepest idle state that satisfies our constraints */
+ for (i = 1; i < dev->state_count; i++) {
+ struct cpuidle_state *s = &dev->states[i];
+
+ if (s->target_residency > data->expected_us)
+ break;
+ if (s->target_residency > data->predicted_us)
+ break;
+ if (s->exit_latency > system_latency_constraint())
+ break;
+ }
+
+ data->last_state_idx = i - 1;
+ return i - 1;
+}
+
+/**
+ * menu_reflect - attempts to guess what happened after entry
+ * @dev: the CPU
+ *
+ * NOTE: it's important to be fast here because this operation will add to
+ * the overall exit latency.
+ */
+static void menu_reflect(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &__get_cpu_var(menu_devices);
+ int last_idx = data->last_state_idx;
+ unsigned int measured_us =
+ cpuidle_get_last_residency(dev) + data->elapsed_us;
+ struct cpuidle_state *target = &dev->states[last_idx];
+
+ /*
+ * Ugh, this idle state doesn't support residency measurements, so we
+ * are basically lost in the dark. As a compromise, assume we slept
+ * for one full standard timer tick. However, be aware that this
+ * could potentially result in a suboptimal state transition.
+ */
+ if (!(target->flags & CPUIDLE_FLAG_TIME_VALID))
+ measured_us = USEC_PER_SEC / HZ;
+
+ /* Predict time remaining until next break event */
+ if (measured_us + BREAK_FUZZ < data->expected_us - target->exit_latency) {
+ data->predicted_us = max(measured_us, data->last_measured_us);
+ data->last_measured_us = measured_us;
+ data->elapsed_us = 0;
+ } else {
+ if (data->elapsed_us < data->elapsed_us + measured_us)
+ data->elapsed_us = measured_us;
+ else
+ data->elapsed_us = -1;
+ data->predicted_us = max(measured_us, data->last_measured_us);
+ }
+}
+
+/**
+ * menu_enable_device - scans a CPU's states and does setup
+ * @dev: the CPU
+ */
+static int menu_enable_device(struct cpuidle_device *dev)
+{
+ struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
+
+ memset(data, 0, sizeof(struct menu_device));
+
+ return 0;
+}
+
+static struct cpuidle_governor menu_governor = {
+ .name = "menu",
+ .rating = 20,
+ .enable = menu_enable_device,
+ .select = menu_select,
+ .reflect = menu_reflect,
+ .owner = THIS_MODULE,
+};
+
+/**
+ * init_menu - initializes the governor
+ */
+static int __init init_menu(void)
+{
+ return cpuidle_register_governor(&menu_governor);
+}
+
+/**
+ * exit_menu - exits the governor
+ */
+static void __exit exit_menu(void)
+{
+ cpuidle_unregister_governor(&menu_governor);
+}
+
+MODULE_LICENSE("GPL");
+module_init(init_menu);
+module_exit(exit_menu);
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-11 06:37:49 +0000