// SPDX-License-Identifier: GPL-2.0-only /* * cpufreq driver for Enhanced SpeedStep, as found in Intel's Pentium * M (part of the Centrino chipset). * * Since the original Pentium M, most new Intel CPUs support Enhanced * SpeedStep. * * Despite the "SpeedStep" in the name, this is almost entirely unlike * traditional SpeedStep. * * Modelled on speedstep.c * * Copyright (C) 2003 Jeremy Fitzhardinge <[email protected]> */ #define pr_fmt(fmt) … #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/cpufreq.h> #include <linux/sched.h> /* current */ #include <linux/delay.h> #include <linux/compiler.h> #include <linux/gfp.h> #include <asm/msr.h> #include <asm/processor.h> #include <asm/cpufeature.h> #include <asm/cpu_device_id.h> #define MAINTAINER … #define INTEL_MSR_RANGE … struct cpu_id { … }; enum { … }; static const struct cpu_id cpu_ids[] = …; #define N_IDS … struct cpu_model { … }; static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c, const struct cpu_id *x); /* Operating points for current CPU */ static DEFINE_PER_CPU(struct cpu_model *, centrino_model); static DEFINE_PER_CPU(const struct cpu_id *, centrino_cpu); static struct cpufreq_driver centrino_driver; #ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE /* Computes the correct form for IA32_PERF_CTL MSR for a particular frequency/voltage operating point; frequency in MHz, volts in mV. This is stored as "driver_data" in the structure. */ #define OP … /* * These voltage tables were derived from the Intel Pentium M * datasheet, document 25261202.pdf, Table 5. I have verified they * are consistent with my IBM ThinkPad X31, which has a 1.3GHz Pentium * M. */ /* Ultra Low Voltage Intel Pentium M processor 900MHz (Banias) */ static struct cpufreq_frequency_table banias_900[] = { OP(600, 844), OP(800, 988), OP(900, 1004), { .frequency = CPUFREQ_TABLE_END } }; /* Ultra Low Voltage Intel Pentium M processor 1000MHz (Banias) */ static struct cpufreq_frequency_table banias_1000[] = { OP(600, 844), OP(800, 972), OP(900, 988), OP(1000, 1004), { .frequency = CPUFREQ_TABLE_END } }; /* Low Voltage Intel Pentium M processor 1.10GHz (Banias) */ static struct cpufreq_frequency_table banias_1100[] = { OP( 600, 956), OP( 800, 1020), OP( 900, 1100), OP(1000, 1164), OP(1100, 1180), { .frequency = CPUFREQ_TABLE_END } }; /* Low Voltage Intel Pentium M processor 1.20GHz (Banias) */ static struct cpufreq_frequency_table banias_1200[] = { OP( 600, 956), OP( 800, 1004), OP( 900, 1020), OP(1000, 1100), OP(1100, 1164), OP(1200, 1180), { .frequency = CPUFREQ_TABLE_END } }; /* Intel Pentium M processor 1.30GHz (Banias) */ static struct cpufreq_frequency_table banias_1300[] = { OP( 600, 956), OP( 800, 1260), OP(1000, 1292), OP(1200, 1356), OP(1300, 1388), { .frequency = CPUFREQ_TABLE_END } }; /* Intel Pentium M processor 1.40GHz (Banias) */ static struct cpufreq_frequency_table banias_1400[] = { OP( 600, 956), OP( 800, 1180), OP(1000, 1308), OP(1200, 1436), OP(1400, 1484), { .frequency = CPUFREQ_TABLE_END } }; /* Intel Pentium M processor 1.50GHz (Banias) */ static struct cpufreq_frequency_table banias_1500[] = { OP( 600, 956), OP( 800, 1116), OP(1000, 1228), OP(1200, 1356), OP(1400, 1452), OP(1500, 1484), { .frequency = CPUFREQ_TABLE_END } }; /* Intel Pentium M processor 1.60GHz (Banias) */ static struct cpufreq_frequency_table banias_1600[] = { OP( 600, 956), OP( 800, 1036), OP(1000, 1164), OP(1200, 1276), OP(1400, 1420), OP(1600, 1484), { .frequency = CPUFREQ_TABLE_END } }; /* Intel Pentium M processor 1.70GHz (Banias) */ static struct cpufreq_frequency_table banias_1700[] = { OP( 600, 956), OP( 800, 1004), OP(1000, 1116), OP(1200, 1228), OP(1400, 1308), OP(1700, 1484), { .frequency = CPUFREQ_TABLE_END } }; #undef OP #define _BANIAS … #define BANIAS … /* CPU models, their operating frequency range, and freq/voltage operating points */ static struct cpu_model models[] = { _BANIAS(&cpu_ids[CPU_BANIAS], 900, " 900"), BANIAS(1000), BANIAS(1100), BANIAS(1200), BANIAS(1300), BANIAS(1400), BANIAS(1500), BANIAS(1600), BANIAS(1700), /* NULL model_name is a wildcard */ { &cpu_ids[CPU_DOTHAN_A1], NULL, 0, NULL }, { &cpu_ids[CPU_DOTHAN_A2], NULL, 0, NULL }, { &cpu_ids[CPU_DOTHAN_B0], NULL, 0, NULL }, { &cpu_ids[CPU_MP4HT_D0], NULL, 0, NULL }, { &cpu_ids[CPU_MP4HT_E0], NULL, 0, NULL }, { NULL, } }; #undef _BANIAS #undef BANIAS static int centrino_cpu_init_table(struct cpufreq_policy *policy) { struct cpuinfo_x86 *cpu = &cpu_data(policy->cpu); struct cpu_model *model; for(model = models; model->cpu_id != NULL; model++) if (centrino_verify_cpu_id(cpu, model->cpu_id) && (model->model_name == NULL || strcmp(cpu->x86_model_id, model->model_name) == 0)) break; if (model->cpu_id == NULL) { /* No match at all */ pr_debug("no support for CPU model \"%s\": " "send /proc/cpuinfo to " MAINTAINER "\n", cpu->x86_model_id); return -ENOENT; } if (model->op_points == NULL) { /* Matched a non-match */ pr_debug("no table support for CPU model \"%s\"\n", cpu->x86_model_id); pr_debug("try using the acpi-cpufreq driver\n"); return -ENOENT; } per_cpu(centrino_model, policy->cpu) = model; pr_debug("found \"%s\": max frequency: %dkHz\n", model->model_name, model->max_freq); return 0; } #else static inline int centrino_cpu_init_table(struct cpufreq_policy *policy) { … } #endif /* CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE */ static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c, const struct cpu_id *x) { … } /* To be called only after centrino_model is initialized */ static unsigned extract_clock(unsigned msr, unsigned int cpu, int failsafe) { … } /* Return the current CPU frequency in kHz */ static unsigned int get_cur_freq(unsigned int cpu) { … } static int centrino_cpu_init(struct cpufreq_policy *policy) { … } static void centrino_cpu_exit(struct cpufreq_policy *policy) { … } /** * centrino_target - set a new CPUFreq policy * @policy: new policy * @index: index of target frequency * * Sets a new CPUFreq policy. */ static int centrino_target(struct cpufreq_policy *policy, unsigned int index) { … } static struct cpufreq_driver centrino_driver = …; /* * This doesn't replace the detailed checks above because * the generic CPU IDs don't have a way to match for steppings * or ASCII model IDs. */ static const struct x86_cpu_id centrino_ids[] = …; /** * centrino_init - initializes the Enhanced SpeedStep CPUFreq driver * * Initializes the Enhanced SpeedStep support. Returns -ENODEV on * unsupported devices, -ENOENT if there's no voltage table for this * particular CPU model, -EINVAL on problems during initiatization, * and zero on success. * * This is quite picky. Not only does the CPU have to advertise the * "est" flag in the cpuid capability flags, we look for a specific * CPU model and stepping, and we need to have the exact model name in * our voltage tables. That is, be paranoid about not releasing * someone's valuable magic smoke. */ static int __init centrino_init(void) { … } static void __exit centrino_exit(void) { … } MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; late_initcall(centrino_init); module_exit(centrino_exit);
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