![Jan Engelhardt](/assets/img/avatar_default.png)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Signed-off-by: Len Brown <len.brown@intel.com>
393 lines
9.3 KiB
C
393 lines
9.3 KiB
C
/*
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* processor_thermal.c - Passive cooling submodule of the ACPI processor driver
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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* Copyright (C) 2004 Dominik Brodowski <linux@brodo.de>
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* Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
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* - Added processor hotplug support
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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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; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for 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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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/cpufreq.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <asm/uaccess.h>
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#include <acpi/acpi_bus.h>
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#include <acpi/processor.h>
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#include <acpi/acpi_drivers.h>
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#define ACPI_PROCESSOR_COMPONENT 0x01000000
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#define ACPI_PROCESSOR_CLASS "processor"
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#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
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#define _COMPONENT ACPI_PROCESSOR_COMPONENT
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ACPI_MODULE_NAME("acpi_processor")
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/* --------------------------------------------------------------------------
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Limit Interface
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-------------------------------------------------------------------------- */
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static int acpi_processor_apply_limit(struct acpi_processor *pr)
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{
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int result = 0;
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u16 px = 0;
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u16 tx = 0;
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if (!pr)
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return -EINVAL;
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if (!pr->flags.limit)
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return -ENODEV;
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if (pr->flags.throttling) {
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if (pr->limit.user.tx > tx)
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tx = pr->limit.user.tx;
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if (pr->limit.thermal.tx > tx)
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tx = pr->limit.thermal.tx;
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result = acpi_processor_set_throttling(pr, tx);
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if (result)
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goto end;
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}
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pr->limit.state.px = px;
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pr->limit.state.tx = tx;
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"Processor [%d] limit set to (P%d:T%d)\n", pr->id,
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pr->limit.state.px, pr->limit.state.tx));
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end:
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if (result)
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printk(KERN_ERR PREFIX "Unable to set limit\n");
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return result;
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}
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#ifdef CONFIG_CPU_FREQ
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/* If a passive cooling situation is detected, primarily CPUfreq is used, as it
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* offers (in most cases) voltage scaling in addition to frequency scaling, and
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* thus a cubic (instead of linear) reduction of energy. Also, we allow for
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* _any_ cpufreq driver and not only the acpi-cpufreq driver.
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*/
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static unsigned int cpufreq_thermal_reduction_pctg[NR_CPUS];
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static unsigned int acpi_thermal_cpufreq_is_init = 0;
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static int cpu_has_cpufreq(unsigned int cpu)
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{
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struct cpufreq_policy policy;
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if (!acpi_thermal_cpufreq_is_init || cpufreq_get_policy(&policy, cpu))
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return 0;
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return 1;
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}
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static int acpi_thermal_cpufreq_increase(unsigned int cpu)
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{
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if (!cpu_has_cpufreq(cpu))
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return -ENODEV;
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if (cpufreq_thermal_reduction_pctg[cpu] < 60) {
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cpufreq_thermal_reduction_pctg[cpu] += 20;
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cpufreq_update_policy(cpu);
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return 0;
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}
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return -ERANGE;
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}
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static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
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{
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if (!cpu_has_cpufreq(cpu))
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return -ENODEV;
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if (cpufreq_thermal_reduction_pctg[cpu] > 20)
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cpufreq_thermal_reduction_pctg[cpu] -= 20;
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else
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cpufreq_thermal_reduction_pctg[cpu] = 0;
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cpufreq_update_policy(cpu);
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/* We reached max freq again and can leave passive mode */
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return !cpufreq_thermal_reduction_pctg[cpu];
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}
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static int acpi_thermal_cpufreq_notifier(struct notifier_block *nb,
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unsigned long event, void *data)
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{
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struct cpufreq_policy *policy = data;
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unsigned long max_freq = 0;
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if (event != CPUFREQ_ADJUST)
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goto out;
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max_freq =
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(policy->cpuinfo.max_freq *
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(100 - cpufreq_thermal_reduction_pctg[policy->cpu])) / 100;
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cpufreq_verify_within_limits(policy, 0, max_freq);
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out:
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return 0;
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}
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static struct notifier_block acpi_thermal_cpufreq_notifier_block = {
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.notifier_call = acpi_thermal_cpufreq_notifier,
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};
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void acpi_thermal_cpufreq_init(void)
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{
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int i;
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for (i = 0; i < NR_CPUS; i++)
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cpufreq_thermal_reduction_pctg[i] = 0;
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i = cpufreq_register_notifier(&acpi_thermal_cpufreq_notifier_block,
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CPUFREQ_POLICY_NOTIFIER);
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if (!i)
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acpi_thermal_cpufreq_is_init = 1;
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}
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void acpi_thermal_cpufreq_exit(void)
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{
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if (acpi_thermal_cpufreq_is_init)
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cpufreq_unregister_notifier
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(&acpi_thermal_cpufreq_notifier_block,
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CPUFREQ_POLICY_NOTIFIER);
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acpi_thermal_cpufreq_is_init = 0;
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}
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#else /* ! CONFIG_CPU_FREQ */
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static int acpi_thermal_cpufreq_increase(unsigned int cpu)
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{
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return -ENODEV;
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}
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static int acpi_thermal_cpufreq_decrease(unsigned int cpu)
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{
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return -ENODEV;
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}
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#endif
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int acpi_processor_set_thermal_limit(acpi_handle handle, int type)
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{
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int result = 0;
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struct acpi_processor *pr = NULL;
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struct acpi_device *device = NULL;
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int tx = 0, max_tx_px = 0;
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if ((type < ACPI_PROCESSOR_LIMIT_NONE)
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|| (type > ACPI_PROCESSOR_LIMIT_DECREMENT))
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return -EINVAL;
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result = acpi_bus_get_device(handle, &device);
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if (result)
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return result;
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pr = acpi_driver_data(device);
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if (!pr)
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return -ENODEV;
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/* Thermal limits are always relative to the current Px/Tx state. */
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if (pr->flags.throttling)
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pr->limit.thermal.tx = pr->throttling.state;
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/*
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* Our default policy is to only use throttling at the lowest
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* performance state.
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*/
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tx = pr->limit.thermal.tx;
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switch (type) {
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case ACPI_PROCESSOR_LIMIT_NONE:
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do {
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result = acpi_thermal_cpufreq_decrease(pr->id);
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} while (!result);
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tx = 0;
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break;
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case ACPI_PROCESSOR_LIMIT_INCREMENT:
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/* if going up: P-states first, T-states later */
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result = acpi_thermal_cpufreq_increase(pr->id);
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if (!result)
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goto end;
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else if (result == -ERANGE)
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"At maximum performance state\n"));
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if (pr->flags.throttling) {
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if (tx == (pr->throttling.state_count - 1))
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"At maximum throttling state\n"));
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else
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tx++;
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}
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break;
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case ACPI_PROCESSOR_LIMIT_DECREMENT:
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/* if going down: T-states first, P-states later */
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if (pr->flags.throttling) {
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if (tx == 0) {
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max_tx_px = 1;
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"At minimum throttling state\n"));
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} else {
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tx--;
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goto end;
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}
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}
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result = acpi_thermal_cpufreq_decrease(pr->id);
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if (result) {
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/*
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* We only could get -ERANGE, 1 or 0.
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* In the first two cases we reached max freq again.
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*/
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ACPI_DEBUG_PRINT((ACPI_DB_INFO,
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"At minimum performance state\n"));
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max_tx_px = 1;
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} else
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max_tx_px = 0;
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break;
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}
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end:
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if (pr->flags.throttling) {
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pr->limit.thermal.px = 0;
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pr->limit.thermal.tx = tx;
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result = acpi_processor_apply_limit(pr);
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if (result)
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printk(KERN_ERR PREFIX "Unable to set thermal limit\n");
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ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Thermal limit now (P%d:T%d)\n",
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pr->limit.thermal.px, pr->limit.thermal.tx));
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} else
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result = 0;
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if (max_tx_px)
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return 1;
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else
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return result;
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}
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int acpi_processor_get_limit_info(struct acpi_processor *pr)
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{
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if (!pr)
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return -EINVAL;
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if (pr->flags.throttling)
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pr->flags.limit = 1;
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return 0;
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}
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/* /proc interface */
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static int acpi_processor_limit_seq_show(struct seq_file *seq, void *offset)
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{
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struct acpi_processor *pr = (struct acpi_processor *)seq->private;
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if (!pr)
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goto end;
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if (!pr->flags.limit) {
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seq_puts(seq, "<not supported>\n");
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goto end;
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}
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seq_printf(seq, "active limit: P%d:T%d\n"
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"user limit: P%d:T%d\n"
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"thermal limit: P%d:T%d\n",
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pr->limit.state.px, pr->limit.state.tx,
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pr->limit.user.px, pr->limit.user.tx,
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pr->limit.thermal.px, pr->limit.thermal.tx);
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end:
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return 0;
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}
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static int acpi_processor_limit_open_fs(struct inode *inode, struct file *file)
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{
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return single_open(file, acpi_processor_limit_seq_show,
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PDE(inode)->data);
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}
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static ssize_t acpi_processor_write_limit(struct file * file,
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const char __user * buffer,
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size_t count, loff_t * data)
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{
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int result = 0;
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struct seq_file *m = file->private_data;
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struct acpi_processor *pr = m->private;
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char limit_string[25] = { '\0' };
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int px = 0;
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int tx = 0;
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if (!pr || (count > sizeof(limit_string) - 1)) {
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return -EINVAL;
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}
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if (copy_from_user(limit_string, buffer, count)) {
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return -EFAULT;
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}
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limit_string[count] = '\0';
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if (sscanf(limit_string, "%d:%d", &px, &tx) != 2) {
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printk(KERN_ERR PREFIX "Invalid data format\n");
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return -EINVAL;
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}
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if (pr->flags.throttling) {
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if ((tx < 0) || (tx > (pr->throttling.state_count - 1))) {
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printk(KERN_ERR PREFIX "Invalid tx\n");
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return -EINVAL;
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}
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pr->limit.user.tx = tx;
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}
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result = acpi_processor_apply_limit(pr);
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return count;
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}
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struct file_operations acpi_processor_limit_fops = {
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.open = acpi_processor_limit_open_fs,
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.read = seq_read,
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.write = acpi_processor_write_limit,
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.llseek = seq_lseek,
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.release = single_release,
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};
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