105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/*
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* Copyright (c) 2012 NVIDIA CORPORATION. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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*/
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/cpuquiet.h>
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#include "cpuquiet.h"
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LIST_HEAD(cpuquiet_governors);
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struct cpuquiet_governor *cpuquiet_curr_governor;
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struct cpuquiet_governor *cpuquiet_get_first_governor(void)
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{
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if (!list_empty(&cpuquiet_governors))
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return list_entry(cpuquiet_governors.next,
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struct cpuquiet_governor,
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governor_list);
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else
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return NULL;
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}
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struct cpuquiet_governor *cpuquiet_find_governor(const char *str)
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{
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struct cpuquiet_governor *gov;
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list_for_each_entry(gov, &cpuquiet_governors, governor_list)
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if (!strnicmp(str, gov->name, CPUQUIET_NAME_LEN))
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return gov;
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return NULL;
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}
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int cpuquiet_switch_governor(struct cpuquiet_governor *gov)
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{
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int err = 0;
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if (cpuquiet_curr_governor) {
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if (cpuquiet_curr_governor->stop)
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cpuquiet_curr_governor->stop();
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module_put(cpuquiet_curr_governor->owner);
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}
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cpuquiet_curr_governor = gov;
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if (gov) {
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if (!try_module_get(cpuquiet_curr_governor->owner))
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return -EINVAL;
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if (gov->start)
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err = gov->start();
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if (!err)
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cpuquiet_curr_governor = gov;
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}
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return err;
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}
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int cpuquiet_register_governor(struct cpuquiet_governor *gov)
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{
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int ret = -EEXIST;
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if (!gov)
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return -EINVAL;
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mutex_lock(&cpuquiet_lock);
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if (cpuquiet_find_governor(gov->name) == NULL) {
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ret = 0;
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list_add_tail(&gov->governor_list, &cpuquiet_governors);
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if (!cpuquiet_curr_governor && cpuquiet_get_driver())
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cpuquiet_switch_governor(gov);
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}
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mutex_unlock(&cpuquiet_lock);
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return ret;
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}
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EXPORT_SYMBOL(cpuquiet_register_governor);
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void cpuquiet_unregister_governor(struct cpuquiet_governor *gov)
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{
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if (!gov)
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return;
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mutex_lock(&cpuquiet_lock);
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if (cpuquiet_curr_governor == gov)
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cpuquiet_switch_governor(NULL);
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list_del(&gov->governor_list);
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mutex_unlock(&cpuquiet_lock);
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}
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EXPORT_SYMBOL(cpuquiet_unregister_governor);
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