/* * Based on documentation provided by Dave Jones. Thanks! * * Licensed under the terms of the GNU GPL License version 2. * * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* */ #include #include #include #include #include #include #include #include #include #include #include #include #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE #include #include #endif #define EPS_BRAND_C7M 0 #define EPS_BRAND_C7 1 #define EPS_BRAND_EDEN 2 #define EPS_BRAND_C3 3 #define EPS_BRAND_C7D 4 struct eps_cpu_data { u32 fsb; #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE u32 bios_limit; #endif struct cpufreq_frequency_table freq_table[]; }; static struct eps_cpu_data *eps_cpu[NR_CPUS]; /* Module parameters */ static int freq_failsafe_off; static int voltage_failsafe_off; static int set_max_voltage; #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE static int ignore_acpi_limit; static struct acpi_processor_performance *eps_acpi_cpu_perf; /* Minimum necessary to get acpi_processor_get_bios_limit() working */ static int eps_acpi_init(void) { eps_acpi_cpu_perf = kzalloc(sizeof(*eps_acpi_cpu_perf), GFP_KERNEL); if (!eps_acpi_cpu_perf) return -ENOMEM; if (!zalloc_cpumask_var(&eps_acpi_cpu_perf->shared_cpu_map, GFP_KERNEL)) { kfree(eps_acpi_cpu_perf); eps_acpi_cpu_perf = NULL; return -ENOMEM; } if (acpi_processor_register_performance(eps_acpi_cpu_perf, 0)) { free_cpumask_var(eps_acpi_cpu_perf->shared_cpu_map); kfree(eps_acpi_cpu_perf); eps_acpi_cpu_perf = NULL; return -EIO; } return 0; } static int eps_acpi_exit(struct cpufreq_policy *policy) { if (eps_acpi_cpu_perf) { acpi_processor_unregister_performance(0); free_cpumask_var(eps_acpi_cpu_perf->shared_cpu_map); kfree(eps_acpi_cpu_perf); eps_acpi_cpu_perf = NULL; } return 0; } #endif static unsigned int eps_get(unsigned int cpu) { struct eps_cpu_data *centaur; u32 lo, hi; if (cpu) return 0; centaur = eps_cpu[cpu]; if (centaur == NULL) return 0; /* Return current frequency */ rdmsr(MSR_IA32_PERF_STATUS, lo, hi); return centaur->fsb * ((lo >> 8) & 0xff); } static int eps_set_state(struct eps_cpu_data *centaur, struct cpufreq_policy *policy, u32 dest_state) { u32 lo, hi; int i; /* Wait while CPU is busy */ rdmsr(MSR_IA32_PERF_STATUS, lo, hi); i = 0; while (lo & ((1 << 16) | (1 << 17))) { udelay(16); rdmsr(MSR_IA32_PERF_STATUS, lo, hi); i++; if (unlikely(i > 64)) { return -ENODEV; } } /* Set new multiplier and voltage */ wrmsr(MSR_IA32_PERF_CTL, dest_state & 0xffff, 0); /* Wait until transition end */ i = 0; do { udelay(16); rdmsr(MSR_IA32_PERF_STATUS, lo, hi); i++; if (unlikely(i > 64)) { return -ENODEV; } } while (lo & ((1 << 16) | (1 << 17))); #ifdef DEBUG { u8 current_multiplier, current_voltage; /* Print voltage and multiplier */ rdmsr(MSR_IA32_PERF_STATUS, lo, hi); current_voltage = lo & 0xff; pr_info("eps: Current voltage = %dmV\n", current_voltage * 16 + 700); current_multiplier = (lo >> 8) & 0xff; pr_info("eps: Current multiplier = %d\n", current_multiplier); } #endif return 0; } static int eps_target(struct cpufreq_policy *policy, unsigned int index) { struct eps_cpu_data *centaur; unsigned int cpu = policy->cpu; unsigned int dest_state; int ret; if (unlikely(eps_cpu[cpu] == NULL)) return -ENODEV; centaur = eps_cpu[cpu]; /* Make frequency transition */ dest_state = centaur->freq_table[index].driver_data & 0xffff; ret = eps_set_state(centaur, policy, dest_state); if (ret) pr_err("eps: Timeout!\n"); return ret; } static int eps_cpu_init(struct cpufreq_policy *policy) { unsigned int i; u32 lo, hi; u64 val; u8 current_multiplier, current_voltage; u8 max_multiplier, max_voltage; u8 min_multiplier, min_voltage; u8 brand = 0; u32 fsb; struct eps_cpu_data *centaur; struct cpuinfo_x86 *c = &cpu_data(0); struct cpufreq_frequency_table *f_table; int k, step, voltage; int ret; int states; #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE unsigned int limit; #endif if (policy->cpu != 0) return -ENODEV; /* Check brand */ pr_info("eps: Detected VIA "); switch (c->x86_model) { case 10: rdmsr(0x1153, lo, hi); brand = (((lo >> 2) ^ lo) >> 18) & 3; pr_cont("Model A "); break; case 13: rdmsr(0x1154, lo, hi); brand = (((lo >> 4) ^ (lo >> 2))) & 0x000000ff; pr_cont("Model D "); break; } switch (brand) { case EPS_BRAND_C7M: pr_cont("C7-M\n"); break; case EPS_BRAND_C7: pr_cont("C7\n"); break; case EPS_BRAND_EDEN: pr_cont("Eden\n"); break; case EPS_BRAND_C7D: pr_cont("C7-D\n"); break; case EPS_BRAND_C3: pr_cont("C3\n"); return -ENODEV; break; } /* Enable Enhanced PowerSaver */ rdmsrl(MSR_IA32_MISC_ENABLE, val); if (!(val & MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP)) { val |= MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP; wrmsrl(MSR_IA32_MISC_ENABLE, val); /* Can be locked at 0 */ rdmsrl(MSR_IA32_MISC_ENABLE, val); if (!(val & MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP)) { pr_info("eps: Can't enable Enhanced PowerSaver\n"); return -ENODEV; } } /* Print voltage and multiplier */ rdmsr(MSR_IA32_PERF_STATUS, lo, hi); current_voltage = lo & 0xff; pr_info("eps: Current voltage = %dmV\n", current_voltage * 16 + 700); current_multiplier = (lo >> 8) & 0xff; pr_info("eps: Current multiplier = %d\n", current_multiplier); /* Print limits */ max_voltage = hi & 0xff; pr_info("eps: Highest voltage = %dmV\n", max_voltage * 16 + 700); max_multiplier = (hi >> 8) & 0xff; pr_info("eps: Highest multiplier = %d\n", max_multiplier); min_voltage = (hi >> 16) & 0xff; pr_info("eps: Lowest voltage = %dmV\n", min_voltage * 16 + 700); min_multiplier = (hi >> 24) & 0xff; pr_info("eps: Lowest multiplier = %d\n", min_multiplier); /* Sanity checks */ if (current_multiplier == 0 || max_multiplier == 0 || min_multiplier == 0) return -EINVAL; if (current_multiplier > max_multiplier || max_multiplier <= min_multiplier) return -EINVAL; if (current_voltage > 0x1f || max_voltage > 0x1f) return -EINVAL; if (max_voltage < min_voltage || current_voltage < min_voltage || current_voltage > max_voltage) return -EINVAL; /* Check for systems using underclocked CPU */ if (!freq_failsafe_off && max_multiplier != current_multiplier) { pr_info("eps: Your processor is running at different frequency then its maximum. Aborting.\n"); pr_info("eps: You can use freq_failsafe_off option to disable this check.\n"); return -EINVAL; } if (!voltage_failsafe_off && max_voltage != current_voltage) { pr_info("eps: Your processor is running at different voltage then its maximum. Aborting.\n"); pr_info("eps: You can use voltage_failsafe_off option to disable this check.\n"); return -EINVAL; } /* Calc FSB speed */ fsb = cpu_khz / current_multiplier; #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE /* Check for ACPI processor speed limit */ if (!ignore_acpi_limit && !eps_acpi_init()) { if (!acpi_processor_get_bios_limit(policy->cpu, &limit)) { pr_info("eps: ACPI limit %u.%uGHz\n", limit/1000000, (limit%1000000)/10000); eps_acpi_exit(policy); /* Check if max_multiplier is in BIOS limits */ if (limit && max_multiplier * fsb > limit) { pr_info("eps: Aborting\n"); return -EINVAL; } } } #endif /* Allow user to set lower maximum voltage then that reported * by processor */ if (brand == EPS_BRAND_C7M && set_max_voltage) { u32 v; /* Change mV to something hardware can use */ v = (set_max_voltage - 700) / 16; /* Check if voltage is within limits */ if (v >= min_voltage && v <= max_voltage) { pr_info("eps: Setting %dmV as maximum\n", v * 16 + 700); max_voltage = v; } } /* Calc number of p-states supported */ if (brand == EPS_BRAND_C7M) states = max_multiplier - min_multiplier + 1; else states = 2; /* Allocate private data and frequency table for current cpu */ centaur = kzalloc(sizeof(*centaur) + (states + 1) * sizeof(struct cpufreq_frequency_table), GFP_KERNEL); if (!centaur) return -ENOMEM; eps_cpu[0] = centaur; /* Copy basic values */ centaur->fsb = fsb; #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE centaur->bios_limit = limit; #endif /* Fill frequency and MSR value table */ f_table = ¢aur->freq_table[0]; if (brand != EPS_BRAND_C7M) { f_table[0].frequency = fsb * min_multiplier; f_table[0].driver_data = (min_multiplier << 8) | min_voltage; f_table[1].frequency = fsb * max_multiplier; f_table[1].driver_data = (max_multiplier << 8) | max_voltage; f_table[2].frequency = CPUFREQ_TABLE_END; } else { k = 0; step = ((max_voltage - min_voltage) * 256) / (max_multiplier - min_multiplier); for (i = min_multiplier; i <= max_multiplier; i++) { voltage = (k * step) / 256 + min_voltage; f_table[k].frequency = fsb * i; f_table[k].driver_data = (i << 8) | voltage; k++; } f_table[k].frequency = CPUFREQ_TABLE_END; } policy->cpuinfo.transition_latency = 140000; /* 844mV -> 700mV in ns */ ret = cpufreq_table_validate_and_show(policy, ¢aur->freq_table[0]); if (ret) { kfree(centaur); return ret; } return 0; } static int eps_cpu_exit(struct cpufreq_policy *policy) { unsigned int cpu = policy->cpu; /* Bye */ kfree(eps_cpu[cpu]); eps_cpu[cpu] = NULL; return 0; } static struct cpufreq_driver eps_driver = { .verify = cpufreq_generic_frequency_table_verify, .target_index = eps_target, .init = eps_cpu_init, .exit = eps_cpu_exit, .get = eps_get, .name = "e_powersaver", .attr = cpufreq_generic_attr, }; /* This driver will work only on Centaur C7 processors with * Enhanced SpeedStep/PowerSaver registers */ static const struct x86_cpu_id eps_cpu_id[] = { { X86_VENDOR_CENTAUR, 6, X86_MODEL_ANY, X86_FEATURE_EST }, {} }; MODULE_DEVICE_TABLE(x86cpu, eps_cpu_id); static int __init eps_init(void) { if (!x86_match_cpu(eps_cpu_id) || boot_cpu_data.x86_model < 10) return -ENODEV; if (cpufreq_register_driver(&eps_driver)) return -EINVAL; return 0; } static void __exit eps_exit(void) { cpufreq_unregister_driver(&eps_driver); } /* Allow user to overclock his machine or to change frequency to higher after * unloading module */ module_param(freq_failsafe_off, int, 0644); MODULE_PARM_DESC(freq_failsafe_off, "Disable current vs max frequency check"); module_param(voltage_failsafe_off, int, 0644); MODULE_PARM_DESC(voltage_failsafe_off, "Disable current vs max voltage check"); #if defined CONFIG_ACPI_PROCESSOR || defined CONFIG_ACPI_PROCESSOR_MODULE module_param(ignore_acpi_limit, int, 0644); MODULE_PARM_DESC(ignore_acpi_limit, "Don't check ACPI's processor speed limit"); #endif module_param(set_max_voltage, int, 0644); MODULE_PARM_DESC(set_max_voltage, "Set maximum CPU voltage (mV) C7-M only"); MODULE_AUTHOR("Rafal Bilski "); MODULE_DESCRIPTION("Enhanced PowerSaver driver for VIA C7 CPU's."); MODULE_LICENSE("GPL"); module_init(eps_init); module_exit(eps_exit);