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After commit61cb5758d3("cpuidle: Add cpuidle.governor= command line parameter") new cpuidle governors are not added to the list of available governors, so governor selection via sysfs doesn't work as expected (even though it is rarely used anyway). Fix that by making cpuidle_register_governor() add new governors to cpuidle_governors again. Fixes:61cb5758d3("cpuidle: Add cpuidle.governor= command line parameter") Reported-by: Kees Cook <keescook@chromium.org> Cc: 5.0+ <stable@vger.kernel.org> # 5.0+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
117 lines
2.7 KiB
C
117 lines
2.7 KiB
C
/*
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* governor.c - governor support
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*
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* (C) 2006-2007 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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* Shaohua Li <shaohua.li@intel.com>
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* Adam Belay <abelay@novell.com>
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*
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* This code is licenced under the GPL.
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*/
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#include <linux/cpu.h>
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#include <linux/cpuidle.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/pm_qos.h>
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#include "cpuidle.h"
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char param_governor[CPUIDLE_NAME_LEN];
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LIST_HEAD(cpuidle_governors);
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struct cpuidle_governor *cpuidle_curr_governor;
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/**
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* __cpuidle_find_governor - finds a governor of the specified name
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* @str: the name
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*
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* Must be called with cpuidle_lock acquired.
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*/
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static struct cpuidle_governor * __cpuidle_find_governor(const char *str)
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{
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struct cpuidle_governor *gov;
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list_for_each_entry(gov, &cpuidle_governors, governor_list)
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if (!strncasecmp(str, gov->name, CPUIDLE_NAME_LEN))
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return gov;
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return NULL;
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}
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/**
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* cpuidle_switch_governor - changes the governor
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* @gov: the new target governor
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* Must be called with cpuidle_lock acquired.
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*/
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int cpuidle_switch_governor(struct cpuidle_governor *gov)
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{
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struct cpuidle_device *dev;
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if (!gov)
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return -EINVAL;
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if (gov == cpuidle_curr_governor)
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return 0;
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cpuidle_uninstall_idle_handler();
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if (cpuidle_curr_governor) {
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list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
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cpuidle_disable_device(dev);
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}
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cpuidle_curr_governor = gov;
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if (gov) {
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list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
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cpuidle_enable_device(dev);
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cpuidle_install_idle_handler();
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printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
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}
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return 0;
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}
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/**
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* cpuidle_register_governor - registers a governor
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* @gov: the governor
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*/
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int cpuidle_register_governor(struct cpuidle_governor *gov)
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{
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int ret = -EEXIST;
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if (!gov || !gov->select)
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return -EINVAL;
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if (cpuidle_disabled())
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return -ENODEV;
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mutex_lock(&cpuidle_lock);
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if (__cpuidle_find_governor(gov->name) == NULL) {
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ret = 0;
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list_add_tail(&gov->governor_list, &cpuidle_governors);
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if (!cpuidle_curr_governor ||
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!strncasecmp(param_governor, gov->name, CPUIDLE_NAME_LEN) ||
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(cpuidle_curr_governor->rating < gov->rating &&
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strncasecmp(param_governor, cpuidle_curr_governor->name,
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CPUIDLE_NAME_LEN)))
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cpuidle_switch_governor(gov);
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}
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mutex_unlock(&cpuidle_lock);
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return ret;
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}
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/**
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* cpuidle_governor_latency_req - Compute a latency constraint for CPU
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* @cpu: Target CPU
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*/
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int cpuidle_governor_latency_req(unsigned int cpu)
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{
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int global_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
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struct device *device = get_cpu_device(cpu);
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int device_req = dev_pm_qos_raw_read_value(device);
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return device_req < global_req ? device_req : global_req;
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}
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