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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 13:12:46 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 13:12:46 -0700
commitc4ec20717313daafba59225f812db89595952b83 (patch)
tree253337453b1dc965c40668e4949337ed1c46cab7 /drivers/cpuidle/governor.c
parentec2626815bf9a9922e49820b03e670e833f3ca3c (diff)
parent00a2b433557f10736e8a02de619b3e9052556c12 (diff)
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (41 commits) ACPICA: hw: Don't carry spinlock over suspend ACPICA: hw: remove use_lock flag from acpi_hw_register_{read, write} ACPI: cpuidle: port idle timer suspend/resume workaround to cpuidle ACPI: clean up acpi_enter_sleep_state_prep Hibernation: Make sure that ACPI is enabled in acpi_hibernation_finish ACPI: suppress uninitialized var warning cpuidle: consolidate 2.6.22 cpuidle branch into one patch ACPI: thinkpad-acpi: skip blanks before the data when parsing sysfs ACPI: AC: Add sysfs interface ACPI: SBS: Add sysfs alarm ACPI: SBS: Add ACPI_PROCFS around procfs handling code. ACPI: SBS: Add support for power_supply class (and sysfs) ACPI: SBS: Make SBS reads table-driven. ACPI: SBS: Simplify data structures in SBS ACPI: SBS: Split host controller (ACPI0001) from SBS driver (ACPI0002) ACPI: EC: Add new query handler to list head. ACPI: Add acpi_bus_generate_event4() function ACPI: Battery: add sysfs alarm ACPI: Battery: Add sysfs support ACPI: Battery: Misc clean-ups, no functional changes ... Fix up conflicts in drivers/misc/thinkpad_acpi.[ch] manually
Diffstat (limited to 'drivers/cpuidle/governor.c')
-rw-r--r--drivers/cpuidle/governor.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/cpuidle/governor.c b/drivers/cpuidle/governor.c
new file mode 100644
index 000000000000..bb699cb2dc5a
--- /dev/null
+++ b/drivers/cpuidle/governor.c
@@ -0,0 +1,141 @@
+/*
+ * governor.c - governor support
+ *
+ * (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/mutex.h>
+#include <linux/module.h>
+#include <linux/cpuidle.h>
+
+#include "cpuidle.h"
+
+LIST_HEAD(cpuidle_governors);
+struct cpuidle_governor *cpuidle_curr_governor;
+
+/**
+ * __cpuidle_find_governor - finds a governor of the specified name
+ * @str: the name
+ *
+ * Must be called with cpuidle_lock aquired.
+ */
+static struct cpuidle_governor * __cpuidle_find_governor(const char *str)
+{
+ struct cpuidle_governor *gov;
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list)
+ if (!strnicmp(str, gov->name, CPUIDLE_NAME_LEN))
+ return gov;
+
+ return NULL;
+}
+
+/**
+ * cpuidle_switch_governor - changes the governor
+ * @gov: the new target governor
+ *
+ * NOTE: "gov" can be NULL to specify disabled
+ * Must be called with cpuidle_lock aquired.
+ */
+int cpuidle_switch_governor(struct cpuidle_governor *gov)
+{
+ struct cpuidle_device *dev;
+
+ if (gov == cpuidle_curr_governor)
+ return 0;
+
+ cpuidle_uninstall_idle_handler();
+
+ if (cpuidle_curr_governor) {
+ list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+ cpuidle_disable_device(dev);
+ module_put(cpuidle_curr_governor->owner);
+ }
+
+ cpuidle_curr_governor = gov;
+
+ if (gov) {
+ if (!try_module_get(cpuidle_curr_governor->owner))
+ return -EINVAL;
+ list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
+ cpuidle_enable_device(dev);
+ cpuidle_install_idle_handler();
+ printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
+ }
+
+ return 0;
+}
+
+/**
+ * cpuidle_register_governor - registers a governor
+ * @gov: the governor
+ */
+int cpuidle_register_governor(struct cpuidle_governor *gov)
+{
+ int ret = -EEXIST;
+
+ if (!gov || !gov->select)
+ return -EINVAL;
+
+ mutex_lock(&cpuidle_lock);
+ if (__cpuidle_find_governor(gov->name) == NULL) {
+ ret = 0;
+ list_add_tail(&gov->governor_list, &cpuidle_governors);
+ if (!cpuidle_curr_governor ||
+ cpuidle_curr_governor->rating < gov->rating)
+ cpuidle_switch_governor(gov);
+ }
+ mutex_unlock(&cpuidle_lock);
+
+ return ret;
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_register_governor);
+
+/**
+ * cpuidle_replace_governor - find a replacement governor
+ * @exclude_rating: the rating that will be skipped while looking for
+ * new governor.
+ */
+static struct cpuidle_governor *cpuidle_replace_governor(int exclude_rating)
+{
+ struct cpuidle_governor *gov;
+ struct cpuidle_governor *ret_gov = NULL;
+ unsigned int max_rating = 0;
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list) {
+ if (gov->rating == exclude_rating)
+ continue;
+ if (gov->rating > max_rating) {
+ max_rating = gov->rating;
+ ret_gov = gov;
+ }
+ }
+
+ return ret_gov;
+}
+
+/**
+ * cpuidle_unregister_governor - unregisters a governor
+ * @gov: the governor
+ */
+void cpuidle_unregister_governor(struct cpuidle_governor *gov)
+{
+ if (!gov)
+ return;
+
+ mutex_lock(&cpuidle_lock);
+ if (gov == cpuidle_curr_governor) {
+ struct cpuidle_governor *new_gov;
+ new_gov = cpuidle_replace_governor(gov->rating);
+ cpuidle_switch_governor(new_gov);
+ }
+ list_del(&gov->governor_list);
+ mutex_unlock(&cpuidle_lock);
+}
+
+EXPORT_SYMBOL_GPL(cpuidle_unregister_governor);