diff options
Diffstat (limited to 'drivers/cpufreq/acpi-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/acpi-cpufreq.c | 773 |
1 files changed, 773 insertions, 0 deletions
diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c new file mode 100644 index 000000000000..4e04e1274388 --- /dev/null +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -0,0 +1,773 @@ +/* + * acpi-cpufreq.c - ACPI Processor P-States Driver + * + * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com> + * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com> + * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de> + * Copyright (C) 2006 Denis Sadykov <denis.m.sadykov@intel.com> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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, or (at + * your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/smp.h> +#include <linux/sched.h> +#include <linux/cpufreq.h> +#include <linux/compiler.h> +#include <linux/dmi.h> +#include <linux/slab.h> + +#include <linux/acpi.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/uaccess.h> + +#include <acpi/processor.h> + +#include <asm/msr.h> +#include <asm/processor.h> +#include <asm/cpufeature.h> +#include "mperf.h" + +MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski"); +MODULE_DESCRIPTION("ACPI Processor P-States Driver"); +MODULE_LICENSE("GPL"); + +enum { + UNDEFINED_CAPABLE = 0, + SYSTEM_INTEL_MSR_CAPABLE, + SYSTEM_IO_CAPABLE, +}; + +#define INTEL_MSR_RANGE (0xffff) + +struct acpi_cpufreq_data { + struct acpi_processor_performance *acpi_data; + struct cpufreq_frequency_table *freq_table; + unsigned int resume; + unsigned int cpu_feature; +}; + +static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data); + +/* acpi_perf_data is a pointer to percpu data. */ +static struct acpi_processor_performance __percpu *acpi_perf_data; + +static struct cpufreq_driver acpi_cpufreq_driver; + +static unsigned int acpi_pstate_strict; + +static int check_est_cpu(unsigned int cpuid) +{ + struct cpuinfo_x86 *cpu = &cpu_data(cpuid); + + return cpu_has(cpu, X86_FEATURE_EST); +} + +static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data) +{ + struct acpi_processor_performance *perf; + int i; + + perf = data->acpi_data; + + for (i = 0; i < perf->state_count; i++) { + if (value == perf->states[i].status) + return data->freq_table[i].frequency; + } + return 0; +} + +static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data) +{ + int i; + struct acpi_processor_performance *perf; + + msr &= INTEL_MSR_RANGE; + perf = data->acpi_data; + + for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) { + if (msr == perf->states[data->freq_table[i].index].status) + return data->freq_table[i].frequency; + } + return data->freq_table[0].frequency; +} + +static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data) +{ + switch (data->cpu_feature) { + case SYSTEM_INTEL_MSR_CAPABLE: + return extract_msr(val, data); + case SYSTEM_IO_CAPABLE: + return extract_io(val, data); + default: + return 0; + } +} + +struct msr_addr { + u32 reg; +}; + +struct io_addr { + u16 port; + u8 bit_width; +}; + +struct drv_cmd { + unsigned int type; + const struct cpumask *mask; + union { + struct msr_addr msr; + struct io_addr io; + } addr; + u32 val; +}; + +/* Called via smp_call_function_single(), on the target CPU */ +static void do_drv_read(void *_cmd) +{ + struct drv_cmd *cmd = _cmd; + u32 h; + + switch (cmd->type) { + case SYSTEM_INTEL_MSR_CAPABLE: + rdmsr(cmd->addr.msr.reg, cmd->val, h); + break; + case SYSTEM_IO_CAPABLE: + acpi_os_read_port((acpi_io_address)cmd->addr.io.port, + &cmd->val, + (u32)cmd->addr.io.bit_width); + break; + default: + break; + } +} + +/* Called via smp_call_function_many(), on the target CPUs */ +static void do_drv_write(void *_cmd) +{ + struct drv_cmd *cmd = _cmd; + u32 lo, hi; + + switch (cmd->type) { + case SYSTEM_INTEL_MSR_CAPABLE: + rdmsr(cmd->addr.msr.reg, lo, hi); + lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE); + wrmsr(cmd->addr.msr.reg, lo, hi); + break; + case SYSTEM_IO_CAPABLE: + acpi_os_write_port((acpi_io_address)cmd->addr.io.port, + cmd->val, + (u32)cmd->addr.io.bit_width); + break; + default: + break; + } +} + +static void drv_read(struct drv_cmd *cmd) +{ + int err; + cmd->val = 0; + + err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1); + WARN_ON_ONCE(err); /* smp_call_function_any() was buggy? */ +} + +static void drv_write(struct drv_cmd *cmd) +{ + int this_cpu; + + this_cpu = get_cpu(); + if (cpumask_test_cpu(this_cpu, cmd->mask)) + do_drv_write(cmd); + smp_call_function_many(cmd->mask, do_drv_write, cmd, 1); + put_cpu(); +} + +static u32 get_cur_val(const struct cpumask *mask) +{ + struct acpi_processor_performance *perf; + struct drv_cmd cmd; + + if (unlikely(cpumask_empty(mask))) + return 0; + + switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) { + case SYSTEM_INTEL_MSR_CAPABLE: + cmd.type = SYSTEM_INTEL_MSR_CAPABLE; + cmd.addr.msr.reg = MSR_IA32_PERF_STATUS; + break; + case SYSTEM_IO_CAPABLE: + cmd.type = SYSTEM_IO_CAPABLE; + perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data; + cmd.addr.io.port = perf->control_register.address; + cmd.addr.io.bit_width = perf->control_register.bit_width; + break; + default: + return 0; + } + + cmd.mask = mask; + drv_read(&cmd); + + pr_debug("get_cur_val = %u\n", cmd.val); + + return cmd.val; +} + +static unsigned int get_cur_freq_on_cpu(unsigned int cpu) +{ + struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu); + unsigned int freq; + unsigned int cached_freq; + + pr_debug("get_cur_freq_on_cpu (%d)\n", cpu); + + if (unlikely(data == NULL || + data->acpi_data == NULL || data->freq_table == NULL)) { + return 0; + } + + cached_freq = data->freq_table[data->acpi_data->state].frequency; + freq = extract_freq(get_cur_val(cpumask_of(cpu)), data); + if (freq != cached_freq) { + /* + * The dreaded BIOS frequency change behind our back. + * Force set the frequency on next target call. + */ + data->resume = 1; + } + + pr_debug("cur freq = %u\n", freq); + + return freq; +} + +static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq, + struct acpi_cpufreq_data *data) +{ + unsigned int cur_freq; + unsigned int i; + + for (i = 0; i < 100; i++) { + cur_freq = extract_freq(get_cur_val(mask), data); + if (cur_freq == freq) + return 1; + udelay(10); + } + return 0; +} + +static int acpi_cpufreq_target(struct cpufreq_policy *policy, + unsigned int target_freq, unsigned int relation) +{ + struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); + struct acpi_processor_performance *perf; + struct cpufreq_freqs freqs; + struct drv_cmd cmd; + unsigned int next_state = 0; /* Index into freq_table */ + unsigned int next_perf_state = 0; /* Index into perf table */ + unsigned int i; + int result = 0; + + pr_debug("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu); + + if (unlikely(data == NULL || + data->acpi_data == NULL || data->freq_table == NULL)) { + return -ENODEV; + } + + perf = data->acpi_data; + result = cpufreq_frequency_table_target(policy, + data->freq_table, + target_freq, + relation, &next_state); + if (unlikely(result)) { + result = -ENODEV; + goto out; + } + + next_perf_state = data->freq_table[next_state].index; + if (perf->state == next_perf_state) { + if (unlikely(data->resume)) { + pr_debug("Called after resume, resetting to P%d\n", + next_perf_state); + data->resume = 0; + } else { + pr_debug("Already at target state (P%d)\n", + next_perf_state); + goto out; + } + } + + switch (data->cpu_feature) { + case SYSTEM_INTEL_MSR_CAPABLE: + cmd.type = SYSTEM_INTEL_MSR_CAPABLE; + cmd.addr.msr.reg = MSR_IA32_PERF_CTL; + cmd.val = (u32) perf->states[next_perf_state].control; + break; + case SYSTEM_IO_CAPABLE: + cmd.type = SYSTEM_IO_CAPABLE; + cmd.addr.io.port = perf->control_register.address; + cmd.addr.io.bit_width = perf->control_register.bit_width; + cmd.val = (u32) perf->states[next_perf_state].control; + break; + default: + result = -ENODEV; + goto out; + } + + /* cpufreq holds the hotplug lock, so we are safe from here on */ + if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY) + cmd.mask = policy->cpus; + else + cmd.mask = cpumask_of(policy->cpu); + + freqs.old = perf->states[perf->state].core_frequency * 1000; + freqs.new = data->freq_table[next_state].frequency; + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + } + + drv_write(&cmd); + + if (acpi_pstate_strict) { + if (!check_freqs(cmd.mask, freqs.new, data)) { + pr_debug("acpi_cpufreq_target failed (%d)\n", + policy->cpu); + result = -EAGAIN; + goto out; + } + } + + for_each_cpu(i, policy->cpus) { + freqs.cpu = i; + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); + } + perf->state = next_perf_state; + +out: + return result; +} + +static int acpi_cpufreq_verify(struct cpufreq_policy *policy) +{ + struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); + + pr_debug("acpi_cpufreq_verify\n"); + + return cpufreq_frequency_table_verify(policy, data->freq_table); +} + +static unsigned long +acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu) +{ + struct acpi_processor_performance *perf = data->acpi_data; + + if (cpu_khz) { + /* search the closest match to cpu_khz */ + unsigned int i; + unsigned long freq; + unsigned long freqn = perf->states[0].core_frequency * 1000; + + for (i = 0; i < (perf->state_count-1); i++) { + freq = freqn; + freqn = perf->states[i+1].core_frequency * 1000; + if ((2 * cpu_khz) > (freqn + freq)) { + perf->state = i; + return freq; + } + } + perf->state = perf->state_count-1; + return freqn; + } else { + /* assume CPU is at P0... */ + perf->state = 0; + return perf->states[0].core_frequency * 1000; + } +} + +static void free_acpi_perf_data(void) +{ + unsigned int i; + + /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */ + for_each_possible_cpu(i) + free_cpumask_var(per_cpu_ptr(acpi_perf_data, i) + ->shared_cpu_map); + free_percpu(acpi_perf_data); +} + +/* + * acpi_cpufreq_early_init - initialize ACPI P-States library + * + * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c) + * in order to determine correct frequency and voltage pairings. We can + * do _PDC and _PSD and find out the processor dependency for the + * actual init that will happen later... + */ +static int __init acpi_cpufreq_early_init(void) +{ + unsigned int i; + pr_debug("acpi_cpufreq_early_init\n"); + + acpi_perf_data = alloc_percpu(struct acpi_processor_performance); + if (!acpi_perf_data) { + pr_debug("Memory allocation error for acpi_perf_data.\n"); + return -ENOMEM; + } + for_each_possible_cpu(i) { + if (!zalloc_cpumask_var_node( + &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map, + GFP_KERNEL, cpu_to_node(i))) { + + /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */ + free_acpi_perf_data(); + return -ENOMEM; + } + } + + /* Do initialization in ACPI core */ + acpi_processor_preregister_performance(acpi_perf_data); + return 0; +} + +#ifdef CONFIG_SMP +/* + * Some BIOSes do SW_ANY coordination internally, either set it up in hw + * or do it in BIOS firmware and won't inform about it to OS. If not + * detected, this has a side effect of making CPU run at a different speed + * than OS intended it to run at. Detect it and handle it cleanly. + */ +static int bios_with_sw_any_bug; + +static int sw_any_bug_found(const struct dmi_system_id *d) +{ + bios_with_sw_any_bug = 1; + return 0; +} + +static const struct dmi_system_id sw_any_bug_dmi_table[] = { + { + .callback = sw_any_bug_found, + .ident = "Supermicro Server X6DLP", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"), + DMI_MATCH(DMI_BIOS_VERSION, "080010"), + DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"), + }, + }, + { } +}; + +static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c) +{ + /* Intel Xeon Processor 7100 Series Specification Update + * http://www.intel.com/Assets/PDF/specupdate/314554.pdf + * AL30: A Machine Check Exception (MCE) Occurring during an + * Enhanced Intel SpeedStep Technology Ratio Change May Cause + * Both Processor Cores to Lock Up. */ + if (c->x86_vendor == X86_VENDOR_INTEL) { + if ((c->x86 == 15) && + (c->x86_model == 6) && + (c->x86_mask == 8)) { + printk(KERN_INFO "acpi-cpufreq: Intel(R) " + "Xeon(R) 7100 Errata AL30, processors may " + "lock up on frequency changes: disabling " + "acpi-cpufreq.\n"); + return -ENODEV; + } + } + return 0; +} +#endif + +static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) +{ + unsigned int i; + unsigned int valid_states = 0; + unsigned int cpu = policy->cpu; + struct acpi_cpufreq_data *data; + unsigned int result = 0; + struct cpuinfo_x86 *c = &cpu_data(policy->cpu); + struct acpi_processor_performance *perf; +#ifdef CONFIG_SMP + static int blacklisted; +#endif + + pr_debug("acpi_cpufreq_cpu_init\n"); + +#ifdef CONFIG_SMP + if (blacklisted) + return blacklisted; + blacklisted = acpi_cpufreq_blacklist(c); + if (blacklisted) + return blacklisted; +#endif + + data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu); + per_cpu(acfreq_data, cpu) = data; + + if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) + acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS; + + result = acpi_processor_register_performance(data->acpi_data, cpu); + if (result) + goto err_free; + + perf = data->acpi_data; + policy->shared_type = perf->shared_type; + + /* + * Will let policy->cpus know about dependency only when software + * coordination is required. + */ + if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL || + policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) { + cpumask_copy(policy->cpus, perf->shared_cpu_map); + } + cpumask_copy(policy->related_cpus, perf->shared_cpu_map); + +#ifdef CONFIG_SMP + dmi_check_system(sw_any_bug_dmi_table); + if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) { + policy->shared_type = CPUFREQ_SHARED_TYPE_ALL; + cpumask_copy(policy->cpus, cpu_core_mask(cpu)); + } +#endif + + /* capability check */ + if (perf->state_count <= 1) { + pr_debug("No P-States\n"); + result = -ENODEV; + goto err_unreg; + } + + if (perf->control_register.space_id != perf->status_register.space_id) { + result = -ENODEV; + goto err_unreg; + } + + switch (perf->control_register.space_id) { + case ACPI_ADR_SPACE_SYSTEM_IO: + pr_debug("SYSTEM IO addr space\n"); + data->cpu_feature = SYSTEM_IO_CAPABLE; + break; + case ACPI_ADR_SPACE_FIXED_HARDWARE: + pr_debug("HARDWARE addr space\n"); + if (!check_est_cpu(cpu)) { + result = -ENODEV; + goto err_unreg; + } + data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE; + break; + default: + pr_debug("Unknown addr space %d\n", + (u32) (perf->control_register.space_id)); + result = -ENODEV; + goto err_unreg; + } + + data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * + (perf->state_count+1), GFP_KERNEL); + if (!data->freq_table) { + result = -ENOMEM; + goto err_unreg; + } + + /* detect transition latency */ + policy->cpuinfo.transition_latency = 0; + for (i = 0; i < perf->state_count; i++) { + if ((perf->states[i].transition_latency * 1000) > + policy->cpuinfo.transition_latency) + policy->cpuinfo.transition_latency = + perf->states[i].transition_latency * 1000; + } + + /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */ + if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE && + policy->cpuinfo.transition_latency > 20 * 1000) { + policy->cpuinfo.transition_latency = 20 * 1000; + printk_once(KERN_INFO + "P-state transition latency capped at 20 uS\n"); + } + + /* table init */ + for (i = 0; i < perf->state_count; i++) { + if (i > 0 && perf->states[i].core_frequency >= + data->freq_table[valid_states-1].frequency / 1000) + continue; + + data->freq_table[valid_states].index = i; + data->freq_table[valid_states].frequency = + perf->states[i].core_frequency * 1000; + valid_states++; + } + data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END; + perf->state = 0; + + result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table); + if (result) + goto err_freqfree; + + if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq) + printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n"); + + switch (perf->control_register.space_id) { + case ACPI_ADR_SPACE_SYSTEM_IO: + /* Current speed is unknown and not detectable by IO port */ + policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu); + break; + case ACPI_ADR_SPACE_FIXED_HARDWARE: + acpi_cpufreq_driver.get = get_cur_freq_on_cpu; + policy->cur = get_cur_freq_on_cpu(cpu); + break; + default: + break; + } + + /* notify BIOS that we exist */ + acpi_processor_notify_smm(THIS_MODULE); + + /* Check for APERF/MPERF support in hardware */ + if (cpu_has(c, X86_FEATURE_APERFMPERF)) + acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf; + + pr_debug("CPU%u - ACPI performance management activated.\n", cpu); + for (i = 0; i < perf->state_count; i++) + pr_debug(" %cP%d: %d MHz, %d mW, %d uS\n", + (i == perf->state ? '*' : ' '), i, + (u32) perf->states[i].core_frequency, + (u32) perf->states[i].power, + (u32) perf->states[i].transition_latency); + + cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu); + + /* + * the first call to ->target() should result in us actually + * writing something to the appropriate registers. + */ + data->resume = 1; + + return result; + +err_freqfree: + kfree(data->freq_table); +err_unreg: + acpi_processor_unregister_performance(perf, cpu); +err_free: + kfree(data); + per_cpu(acfreq_data, cpu) = NULL; + + return result; +} + +static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy) +{ + struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); + + pr_debug("acpi_cpufreq_cpu_exit\n"); + + if (data) { + cpufreq_frequency_table_put_attr(policy->cpu); + per_cpu(acfreq_data, policy->cpu) = NULL; + acpi_processor_unregister_performance(data->acpi_data, + policy->cpu); + kfree(data->freq_table); + kfree(data); + } + + return 0; +} + +static int acpi_cpufreq_resume(struct cpufreq_policy *policy) +{ + struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu); + + pr_debug("acpi_cpufreq_resume\n"); + + data->resume = 1; + + return 0; +} + +static struct freq_attr *acpi_cpufreq_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + +static struct cpufreq_driver acpi_cpufreq_driver = { + .verify = acpi_cpufreq_verify, + .target = acpi_cpufreq_target, + .bios_limit = acpi_processor_get_bios_limit, + .init = acpi_cpufreq_cpu_init, + .exit = acpi_cpufreq_cpu_exit, + .resume = acpi_cpufreq_resume, + .name = "acpi-cpufreq", + .owner = THIS_MODULE, + .attr = acpi_cpufreq_attr, +}; + +static int __init acpi_cpufreq_init(void) +{ + int ret; + + if (acpi_disabled) + return 0; + + pr_debug("acpi_cpufreq_init\n"); + + ret = acpi_cpufreq_early_init(); + if (ret) + return ret; + + ret = cpufreq_register_driver(&acpi_cpufreq_driver); + if (ret) + free_acpi_perf_data(); + + return ret; +} + +static void __exit acpi_cpufreq_exit(void) +{ + pr_debug("acpi_cpufreq_exit\n"); + + cpufreq_unregister_driver(&acpi_cpufreq_driver); + + free_percpu(acpi_perf_data); +} + +module_param(acpi_pstate_strict, uint, 0644); +MODULE_PARM_DESC(acpi_pstate_strict, + "value 0 or non-zero. non-zero -> strict ACPI checks are " + "performed during frequency changes."); + +late_initcall(acpi_cpufreq_init); +module_exit(acpi_cpufreq_exit); + +MODULE_ALIAS("acpi"); |