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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 13:12:46 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-19 13:12:46 -0700 |
commit | c4ec20717313daafba59225f812db89595952b83 (patch) | |
tree | 253337453b1dc965c40668e4949337ed1c46cab7 /drivers/cpuidle/governor.c | |
parent | ec2626815bf9a9922e49820b03e670e833f3ca3c (diff) | |
parent | 00a2b433557f10736e8a02de619b3e9052556c12 (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.c | 141 |
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); |