439 lines
9.8 KiB
C
439 lines
9.8 KiB
C
/*
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* This file provides the ACPI based P-state support. This
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* module works with generic cpufreq infrastructure. Most of
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* the code is based on i386 version
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* (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
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*
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* Copyright (C) 2005 Intel Corp
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* Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
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*/
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#include <linux/kernel.h>
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#include <linux/slab.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/io.h>
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#include <asm/uaccess.h>
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#include <asm/pal.h>
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#include <linux/acpi.h>
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#include <acpi/processor.h>
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MODULE_AUTHOR("Venkatesh Pallipadi");
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MODULE_DESCRIPTION("ACPI Processor P-States Driver");
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MODULE_LICENSE("GPL");
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struct cpufreq_acpi_io {
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struct acpi_processor_performance acpi_data;
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struct cpufreq_frequency_table *freq_table;
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unsigned int resume;
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};
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static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
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static struct cpufreq_driver acpi_cpufreq_driver;
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static int
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processor_set_pstate (
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u32 value)
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{
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s64 retval;
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pr_debug("processor_set_pstate\n");
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retval = ia64_pal_set_pstate((u64)value);
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if (retval) {
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pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
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value, retval);
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return -ENODEV;
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}
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return (int)retval;
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}
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static int
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processor_get_pstate (
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u32 *value)
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{
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u64 pstate_index = 0;
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s64 retval;
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pr_debug("processor_get_pstate\n");
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retval = ia64_pal_get_pstate(&pstate_index,
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PAL_GET_PSTATE_TYPE_INSTANT);
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*value = (u32) pstate_index;
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if (retval)
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pr_debug("Failed to get current freq with "
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"error 0x%lx, idx 0x%x\n", retval, *value);
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return (int)retval;
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}
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/* To be used only after data->acpi_data is initialized */
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static unsigned
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extract_clock (
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struct cpufreq_acpi_io *data,
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unsigned value,
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unsigned int cpu)
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{
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unsigned long i;
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pr_debug("extract_clock\n");
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for (i = 0; i < data->acpi_data.state_count; i++) {
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if (value == data->acpi_data.states[i].status)
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return data->acpi_data.states[i].core_frequency;
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}
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return data->acpi_data.states[i-1].core_frequency;
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}
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static unsigned int
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processor_get_freq (
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struct cpufreq_acpi_io *data,
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unsigned int cpu)
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{
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int ret = 0;
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u32 value = 0;
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cpumask_t saved_mask;
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unsigned long clock_freq;
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pr_debug("processor_get_freq\n");
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saved_mask = current->cpus_allowed;
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set_cpus_allowed_ptr(current, cpumask_of(cpu));
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if (smp_processor_id() != cpu)
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goto migrate_end;
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/* processor_get_pstate gets the instantaneous frequency */
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ret = processor_get_pstate(&value);
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if (ret) {
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set_cpus_allowed_ptr(current, &saved_mask);
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printk(KERN_WARNING "get performance failed with error %d\n",
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ret);
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ret = 0;
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goto migrate_end;
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}
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clock_freq = extract_clock(data, value, cpu);
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ret = (clock_freq*1000);
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migrate_end:
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set_cpus_allowed_ptr(current, &saved_mask);
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return ret;
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}
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static int
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processor_set_freq (
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struct cpufreq_acpi_io *data,
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struct cpufreq_policy *policy,
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int state)
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{
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int ret = 0;
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u32 value = 0;
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struct cpufreq_freqs cpufreq_freqs;
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cpumask_t saved_mask;
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int retval;
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pr_debug("processor_set_freq\n");
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saved_mask = current->cpus_allowed;
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set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
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if (smp_processor_id() != policy->cpu) {
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retval = -EAGAIN;
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goto migrate_end;
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}
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if (state == data->acpi_data.state) {
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if (unlikely(data->resume)) {
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pr_debug("Called after resume, resetting to P%d\n", state);
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data->resume = 0;
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} else {
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pr_debug("Already at target state (P%d)\n", state);
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retval = 0;
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goto migrate_end;
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}
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}
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pr_debug("Transitioning from P%d to P%d\n",
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data->acpi_data.state, state);
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/* cpufreq frequency struct */
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cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
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cpufreq_freqs.new = data->freq_table[state].frequency;
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/* notify cpufreq */
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cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_PRECHANGE);
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/*
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* First we write the target state's 'control' value to the
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* control_register.
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*/
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value = (u32) data->acpi_data.states[state].control;
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pr_debug("Transitioning to state: 0x%08x\n", value);
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ret = processor_set_pstate(value);
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if (ret) {
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unsigned int tmp = cpufreq_freqs.new;
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cpufreq_notify_transition(policy, &cpufreq_freqs,
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CPUFREQ_POSTCHANGE);
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cpufreq_freqs.new = cpufreq_freqs.old;
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cpufreq_freqs.old = tmp;
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cpufreq_notify_transition(policy, &cpufreq_freqs,
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CPUFREQ_PRECHANGE);
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cpufreq_notify_transition(policy, &cpufreq_freqs,
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CPUFREQ_POSTCHANGE);
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printk(KERN_WARNING "Transition failed with error %d\n", ret);
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retval = -ENODEV;
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goto migrate_end;
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}
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cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_POSTCHANGE);
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data->acpi_data.state = state;
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retval = 0;
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migrate_end:
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set_cpus_allowed_ptr(current, &saved_mask);
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return (retval);
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}
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static unsigned int
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acpi_cpufreq_get (
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unsigned int cpu)
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{
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struct cpufreq_acpi_io *data = acpi_io_data[cpu];
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pr_debug("acpi_cpufreq_get\n");
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return processor_get_freq(data, cpu);
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}
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static int
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acpi_cpufreq_target (
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struct cpufreq_policy *policy,
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unsigned int target_freq,
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unsigned int relation)
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{
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struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
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unsigned int next_state = 0;
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unsigned int result = 0;
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pr_debug("acpi_cpufreq_setpolicy\n");
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result = cpufreq_frequency_table_target(policy,
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data->freq_table, target_freq, relation, &next_state);
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if (result)
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return (result);
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result = processor_set_freq(data, policy, next_state);
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return (result);
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}
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static int
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acpi_cpufreq_verify (
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struct cpufreq_policy *policy)
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{
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unsigned int result = 0;
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struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
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pr_debug("acpi_cpufreq_verify\n");
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result = cpufreq_frequency_table_verify(policy,
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data->freq_table);
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return (result);
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}
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static int
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acpi_cpufreq_cpu_init (
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struct cpufreq_policy *policy)
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{
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unsigned int i;
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unsigned int cpu = policy->cpu;
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struct cpufreq_acpi_io *data;
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unsigned int result = 0;
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pr_debug("acpi_cpufreq_cpu_init\n");
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data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
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if (!data)
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return (-ENOMEM);
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acpi_io_data[cpu] = data;
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result = acpi_processor_register_performance(&data->acpi_data, cpu);
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if (result)
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goto err_free;
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/* capability check */
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if (data->acpi_data.state_count <= 1) {
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pr_debug("No P-States\n");
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result = -ENODEV;
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goto err_unreg;
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}
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if ((data->acpi_data.control_register.space_id !=
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ACPI_ADR_SPACE_FIXED_HARDWARE) ||
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(data->acpi_data.status_register.space_id !=
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ACPI_ADR_SPACE_FIXED_HARDWARE)) {
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pr_debug("Unsupported address space [%d, %d]\n",
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(u32) (data->acpi_data.control_register.space_id),
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(u32) (data->acpi_data.status_register.space_id));
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result = -ENODEV;
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goto err_unreg;
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}
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/* alloc freq_table */
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data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
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(data->acpi_data.state_count + 1),
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GFP_KERNEL);
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if (!data->freq_table) {
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result = -ENOMEM;
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goto err_unreg;
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}
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/* detect transition latency */
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policy->cpuinfo.transition_latency = 0;
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for (i=0; i<data->acpi_data.state_count; i++) {
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if ((data->acpi_data.states[i].transition_latency * 1000) >
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policy->cpuinfo.transition_latency) {
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policy->cpuinfo.transition_latency =
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data->acpi_data.states[i].transition_latency * 1000;
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}
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}
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policy->cur = processor_get_freq(data, policy->cpu);
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/* table init */
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for (i = 0; i <= data->acpi_data.state_count; i++)
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{
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data->freq_table[i].index = i;
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if (i < data->acpi_data.state_count) {
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data->freq_table[i].frequency =
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data->acpi_data.states[i].core_frequency * 1000;
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} else {
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data->freq_table[i].frequency = CPUFREQ_TABLE_END;
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}
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}
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result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
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if (result) {
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goto err_freqfree;
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}
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/* notify BIOS that we exist */
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acpi_processor_notify_smm(THIS_MODULE);
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printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
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"activated.\n", cpu);
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for (i = 0; i < data->acpi_data.state_count; i++)
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pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
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(i == data->acpi_data.state?'*':' '), i,
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(u32) data->acpi_data.states[i].core_frequency,
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(u32) data->acpi_data.states[i].power,
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(u32) data->acpi_data.states[i].transition_latency,
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(u32) data->acpi_data.states[i].bus_master_latency,
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(u32) data->acpi_data.states[i].status,
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(u32) data->acpi_data.states[i].control);
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cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
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/* the first call to ->target() should result in us actually
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* writing something to the appropriate registers. */
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data->resume = 1;
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return (result);
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err_freqfree:
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kfree(data->freq_table);
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err_unreg:
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acpi_processor_unregister_performance(&data->acpi_data, cpu);
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err_free:
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kfree(data);
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acpi_io_data[cpu] = NULL;
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return (result);
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}
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static int
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acpi_cpufreq_cpu_exit (
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struct cpufreq_policy *policy)
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{
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struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
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pr_debug("acpi_cpufreq_cpu_exit\n");
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if (data) {
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cpufreq_frequency_table_put_attr(policy->cpu);
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acpi_io_data[policy->cpu] = NULL;
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acpi_processor_unregister_performance(&data->acpi_data,
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policy->cpu);
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kfree(data);
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}
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return (0);
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}
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static struct freq_attr* acpi_cpufreq_attr[] = {
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&cpufreq_freq_attr_scaling_available_freqs,
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NULL,
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};
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static struct cpufreq_driver acpi_cpufreq_driver = {
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.verify = acpi_cpufreq_verify,
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.target = acpi_cpufreq_target,
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.get = acpi_cpufreq_get,
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.init = acpi_cpufreq_cpu_init,
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.exit = acpi_cpufreq_cpu_exit,
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.name = "acpi-cpufreq",
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.owner = THIS_MODULE,
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.attr = acpi_cpufreq_attr,
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};
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static int __init
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acpi_cpufreq_init (void)
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{
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pr_debug("acpi_cpufreq_init\n");
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return cpufreq_register_driver(&acpi_cpufreq_driver);
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}
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static void __exit
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acpi_cpufreq_exit (void)
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{
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pr_debug("acpi_cpufreq_exit\n");
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cpufreq_unregister_driver(&acpi_cpufreq_driver);
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return;
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}
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late_initcall(acpi_cpufreq_init);
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module_exit(acpi_cpufreq_exit);
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