560 lines
14 KiB
C
560 lines
14 KiB
C
/*
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* acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
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*
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* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
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* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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* Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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*/
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#include <linux/config.h>
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#include <linux/kernel.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 <linux/compiler.h>
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#include <linux/sched.h> /* current */
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#include <asm/io.h>
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#include <asm/delay.h>
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#include <asm/uaccess.h>
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#include <linux/acpi.h>
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#include <acpi/processor.h>
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#include "speedstep-est-common.h"
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#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
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MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
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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 unsigned int acpi_pstate_strict;
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static int
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acpi_processor_write_port(
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u16 port,
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u8 bit_width,
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u32 value)
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{
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if (bit_width <= 8) {
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outb(value, port);
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} else if (bit_width <= 16) {
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outw(value, port);
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} else if (bit_width <= 32) {
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outl(value, port);
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} else {
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return -ENODEV;
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}
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return 0;
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}
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static int
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acpi_processor_read_port(
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u16 port,
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u8 bit_width,
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u32 *ret)
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{
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*ret = 0;
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if (bit_width <= 8) {
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*ret = inb(port);
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} else if (bit_width <= 16) {
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*ret = inw(port);
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} else if (bit_width <= 32) {
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*ret = inl(port);
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} else {
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return -ENODEV;
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}
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return 0;
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}
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static int
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acpi_processor_set_performance (
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struct cpufreq_acpi_io *data,
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unsigned int cpu,
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int state)
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{
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u16 port = 0;
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u8 bit_width = 0;
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int ret = 0;
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u32 value = 0;
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int i = 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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dprintk("acpi_processor_set_performance\n");
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/*
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* TBD: Use something other than set_cpus_allowed.
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* As set_cpus_allowed is a bit racy,
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* with any other set_cpus_allowed for this process.
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*/
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saved_mask = current->cpus_allowed;
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set_cpus_allowed(current, cpumask_of_cpu(cpu));
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if (smp_processor_id() != cpu) {
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return (-EAGAIN);
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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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dprintk("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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dprintk("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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dprintk("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.cpu = cpu;
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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(&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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port = data->acpi_data.control_register.address;
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bit_width = data->acpi_data.control_register.bit_width;
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value = (u32) data->acpi_data.states[state].control;
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dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
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ret = acpi_processor_write_port(port, bit_width, value);
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if (ret) {
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dprintk("Invalid port width 0x%04x\n", bit_width);
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retval = ret;
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goto migrate_end;
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}
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/*
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* Assume the write went through when acpi_pstate_strict is not used.
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* As read status_register is an expensive operation and there
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* are no specific error cases where an IO port write will fail.
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*/
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if (acpi_pstate_strict) {
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/* Then we read the 'status_register' and compare the value
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* with the target state's 'status' to make sure the
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* transition was successful.
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* Note that we'll poll for up to 1ms (100 cycles of 10us)
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* before giving up.
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*/
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port = data->acpi_data.status_register.address;
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bit_width = data->acpi_data.status_register.bit_width;
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dprintk("Looking for 0x%08x from port 0x%04x\n",
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(u32) data->acpi_data.states[state].status, port);
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for (i=0; i<100; i++) {
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ret = acpi_processor_read_port(port, bit_width, &value);
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if (ret) {
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dprintk("Invalid port width 0x%04x\n", bit_width);
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retval = ret;
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goto migrate_end;
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}
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if (value == (u32) data->acpi_data.states[state].status)
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break;
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udelay(10);
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}
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} else {
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i = 0;
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value = (u32) data->acpi_data.states[state].status;
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}
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/* notify cpufreq */
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cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
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if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
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unsigned int tmp = cpufreq_freqs.new;
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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(&cpufreq_freqs, CPUFREQ_PRECHANGE);
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cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
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printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
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retval = -ENODEV;
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goto migrate_end;
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}
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dprintk("Transition successful after %d microseconds\n", i * 10);
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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(current, saved_mask);
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return (retval);
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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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dprintk("acpi_cpufreq_setpolicy\n");
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result = cpufreq_frequency_table_target(policy,
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data->freq_table,
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target_freq,
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relation,
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&next_state);
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if (result)
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return (result);
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result = acpi_processor_set_performance (data, policy->cpu, 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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dprintk("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 unsigned long
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acpi_cpufreq_guess_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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if (cpu_khz) {
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/* search the closest match to cpu_khz */
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unsigned int i;
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unsigned long freq;
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unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
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for (i=0; i < (data->acpi_data.state_count - 1); i++) {
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freq = freqn;
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freqn = data->acpi_data.states[i+1].core_frequency * 1000;
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if ((2 * cpu_khz) > (freqn + freq)) {
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data->acpi_data.state = i;
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return (freq);
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}
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}
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data->acpi_data.state = data->acpi_data.state_count - 1;
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return (freqn);
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} else
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/* assume CPU is at P0... */
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data->acpi_data.state = 0;
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return data->acpi_data.states[0].core_frequency * 1000;
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}
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/*
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* acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
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* of this driver
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* @perf: processor-specific acpi_io_data struct
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* @cpu: CPU being initialized
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*
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* To avoid issues with legacy OSes, some BIOSes require to be informed of
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* the SMP capabilities of OS P-state driver. Here we set the bits in _PDC
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* accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
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* driver/acpi/processor.c
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*/
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static void
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acpi_processor_cpu_init_pdc_est(
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struct acpi_processor_performance *perf,
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unsigned int cpu,
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struct acpi_object_list *obj_list
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)
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{
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union acpi_object *obj;
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u32 *buf;
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struct cpuinfo_x86 *c = cpu_data + cpu;
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dprintk("acpi_processor_cpu_init_pdc_est\n");
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if (!cpu_has(c, X86_FEATURE_EST))
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return;
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/* Initialize pdc. It will be used later. */
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if (!obj_list)
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return;
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if (!(obj_list->count && obj_list->pointer))
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return;
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obj = obj_list->pointer;
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if ((obj->buffer.length == 12) && obj->buffer.pointer) {
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buf = (u32 *)obj->buffer.pointer;
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buf[0] = ACPI_PDC_REVISION_ID;
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buf[1] = 1;
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buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
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perf->pdc = obj_list;
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}
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return;
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}
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/* CPU specific PDC initialization */
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static void
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acpi_processor_cpu_init_pdc(
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struct acpi_processor_performance *perf,
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unsigned int cpu,
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struct acpi_object_list *obj_list
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)
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{
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struct cpuinfo_x86 *c = cpu_data + cpu;
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dprintk("acpi_processor_cpu_init_pdc\n");
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perf->pdc = NULL;
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if (cpu_has(c, X86_FEATURE_EST))
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acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
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return;
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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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union acpi_object arg0 = {ACPI_TYPE_BUFFER};
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u32 arg0_buf[3];
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struct acpi_object_list arg_list = {1, &arg0};
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dprintk("acpi_cpufreq_cpu_init\n");
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/* setup arg_list for _PDC settings */
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arg0.buffer.length = 12;
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arg0.buffer.pointer = (u8 *) arg0_buf;
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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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acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
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result = acpi_processor_register_performance(&data->acpi_data, cpu);
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data->acpi_data.pdc = NULL;
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if (result)
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goto err_free;
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if (is_const_loops_cpu(cpu)) {
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acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
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}
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/* capability check */
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if (data->acpi_data.state_count <= 1) {
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dprintk("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 != ACPI_ADR_SPACE_SYSTEM_IO) ||
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(data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
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dprintk("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) * (data->acpi_data.state_count + 1), 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) > policy->cpuinfo.transition_latency)
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policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
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}
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policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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/* The current speed is unknown and not detectable by ACPI... */
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policy->cur = acpi_cpufreq_guess_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 = 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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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 activated.\n",
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cpu);
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for (i = 0; i < data->acpi_data.state_count; i++)
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dprintk(" %cP%d: %d MHz, %d mW, %d uS\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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cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
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/*
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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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*/
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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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dprintk("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, 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 int
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acpi_cpufreq_resume (
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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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dprintk("acpi_cpufreq_resume\n");
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data->resume = 1;
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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,
|
|
.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 result = 0;
|
|
|
|
dprintk("acpi_cpufreq_init\n");
|
|
|
|
result = cpufreq_register_driver(&acpi_cpufreq_driver);
|
|
|
|
return (result);
|
|
}
|
|
|
|
|
|
static void __exit
|
|
acpi_cpufreq_exit (void)
|
|
{
|
|
dprintk("acpi_cpufreq_exit\n");
|
|
|
|
cpufreq_unregister_driver(&acpi_cpufreq_driver);
|
|
|
|
return;
|
|
}
|
|
|
|
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");
|