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2504ba9f59
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 53 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.904365654@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
128 lines
3.1 KiB
C
128 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* SFI Performance States Driver
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*
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* Author: Vishwesh M Rudramuni <vishwesh.m.rudramuni@intel.com>
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* Author: Srinidhi Kasagar <srinidhi.kasagar@intel.com>
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*/
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#include <linux/cpufreq.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/sfi.h>
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#include <linux/slab.h>
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#include <linux/smp.h>
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#include <asm/msr.h>
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static struct cpufreq_frequency_table *freq_table;
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static struct sfi_freq_table_entry *sfi_cpufreq_array;
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static int num_freq_table_entries;
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static int sfi_parse_freq(struct sfi_table_header *table)
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{
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struct sfi_table_simple *sb;
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struct sfi_freq_table_entry *pentry;
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int totallen;
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sb = (struct sfi_table_simple *)table;
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num_freq_table_entries = SFI_GET_NUM_ENTRIES(sb,
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struct sfi_freq_table_entry);
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if (num_freq_table_entries <= 1) {
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pr_err("No p-states discovered\n");
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return -ENODEV;
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}
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pentry = (struct sfi_freq_table_entry *)sb->pentry;
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totallen = num_freq_table_entries * sizeof(*pentry);
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sfi_cpufreq_array = kmemdup(pentry, totallen, GFP_KERNEL);
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if (!sfi_cpufreq_array)
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return -ENOMEM;
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return 0;
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}
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static int sfi_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
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{
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unsigned int next_perf_state = 0; /* Index into perf table */
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u32 lo, hi;
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next_perf_state = policy->freq_table[index].driver_data;
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rdmsr_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, &lo, &hi);
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lo = (lo & ~INTEL_PERF_CTL_MASK) |
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((u32) sfi_cpufreq_array[next_perf_state].ctrl_val &
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INTEL_PERF_CTL_MASK);
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wrmsr_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, lo, hi);
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return 0;
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}
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static int sfi_cpufreq_cpu_init(struct cpufreq_policy *policy)
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{
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policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
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policy->cpuinfo.transition_latency = 100000; /* 100us */
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policy->freq_table = freq_table;
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return 0;
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}
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static struct cpufreq_driver sfi_cpufreq_driver = {
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.flags = CPUFREQ_CONST_LOOPS,
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = sfi_cpufreq_target,
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.init = sfi_cpufreq_cpu_init,
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.name = "sfi-cpufreq",
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.attr = cpufreq_generic_attr,
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};
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static int __init sfi_cpufreq_init(void)
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{
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int ret, i;
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/* parse the freq table from SFI */
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ret = sfi_table_parse(SFI_SIG_FREQ, NULL, NULL, sfi_parse_freq);
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if (ret)
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return ret;
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freq_table = kcalloc(num_freq_table_entries + 1, sizeof(*freq_table),
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GFP_KERNEL);
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if (!freq_table) {
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ret = -ENOMEM;
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goto err_free_array;
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}
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for (i = 0; i < num_freq_table_entries; i++) {
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freq_table[i].driver_data = i;
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freq_table[i].frequency = sfi_cpufreq_array[i].freq_mhz * 1000;
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}
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freq_table[i].frequency = CPUFREQ_TABLE_END;
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ret = cpufreq_register_driver(&sfi_cpufreq_driver);
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if (ret)
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goto err_free_tbl;
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return ret;
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err_free_tbl:
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kfree(freq_table);
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err_free_array:
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kfree(sfi_cpufreq_array);
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return ret;
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}
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late_initcall(sfi_cpufreq_init);
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static void __exit sfi_cpufreq_exit(void)
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{
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cpufreq_unregister_driver(&sfi_cpufreq_driver);
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kfree(freq_table);
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kfree(sfi_cpufreq_array);
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}
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module_exit(sfi_cpufreq_exit);
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MODULE_AUTHOR("Vishwesh M Rudramuni <vishwesh.m.rudramuni@intel.com>");
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MODULE_DESCRIPTION("SFI Performance-States Driver");
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MODULE_LICENSE("GPL");
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