[ACPI] fix reboot upon suspend-to-disk

[mirror_ubuntu-disco-kernel.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c

/*
 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
 *
 *  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>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/compiler.h>
#include <linux/sched.h>        /* current */
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/uaccess.h>

#include <linux/acpi.h>
#include <acpi/processor.h>

#include "speedstep-est-common.h"

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)

MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");


struct cpufreq_acpi_io {
        struct acpi_processor_performance       acpi_data;
        struct cpufreq_frequency_table          *freq_table;
        unsigned int                            resume;
};

static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];

static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;

static int
acpi_processor_write_port(
        u16     port,
        u8      bit_width,
        u32     value)
{
        if (bit_width <= 8) {
                outb(value, port);
        } else if (bit_width <= 16) {
                outw(value, port);
        } else if (bit_width <= 32) {
                outl(value, port);
        } else {
                return -ENODEV;
        }
        return 0;
}

static int
acpi_processor_read_port(
        u16     port,
        u8      bit_width,
        u32     *ret)
{
        *ret = 0;
        if (bit_width <= 8) {
                *ret = inb(port);
        } else if (bit_width <= 16) {
                *ret = inw(port);
        } else if (bit_width <= 32) {
                *ret = inl(port);
        } else {
                return -ENODEV;
        }
        return 0;
}

static int
acpi_processor_set_performance (
        struct cpufreq_acpi_io  *data,
        unsigned int            cpu,
        int                     state)
{
        u16                     port = 0;
        u8                      bit_width = 0;
        int                     ret = 0;
        u32                     value = 0;
        int                     i = 0;
        struct cpufreq_freqs    cpufreq_freqs;
        cpumask_t               saved_mask;
        int                     retval;

        dprintk("acpi_processor_set_performance\n");

        /*
         * TBD: Use something other than set_cpus_allowed.
         * As set_cpus_allowed is a bit racy, 
         * with any other set_cpus_allowed for this process.
         */
        saved_mask = current->cpus_allowed;
        set_cpus_allowed(current, cpumask_of_cpu(cpu));
        if (smp_processor_id() != cpu) {
                return (-EAGAIN);
        }
        
        if (state == data->acpi_data.state) {
                if (unlikely(data->resume)) {
                        dprintk("Called after resume, resetting to P%d\n", state);
                        data->resume = 0;
                } else {
                        dprintk("Already at target state (P%d)\n", state);
                        retval = 0;
                        goto migrate_end;
                }
        }

        dprintk("Transitioning from P%d to P%d\n",
                data->acpi_data.state, state);

        /* cpufreq frequency struct */
        cpufreq_freqs.cpu = cpu;
        cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
        cpufreq_freqs.new = data->freq_table[state].frequency;

        /* notify cpufreq */
        cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);

        /*
         * First we write the target state's 'control' value to the
         * control_register.
         */

        port = data->acpi_data.control_register.address;
        bit_width = data->acpi_data.control_register.bit_width;
        value = (u32) data->acpi_data.states[state].control;

        dprintk("Writing 0x%08x to port 0x%04x\n", value, port);

        ret = acpi_processor_write_port(port, bit_width, value);
        if (ret) {
                dprintk("Invalid port width 0x%04x\n", bit_width);
                retval = ret;
                goto migrate_end;
        }

        /*
         * Assume the write went through when acpi_pstate_strict is not used.
         * As read status_register is an expensive operation and there 
         * are no specific error cases where an IO port write will fail.
         */
        if (acpi_pstate_strict) {
                /* Then we read the 'status_register' and compare the value 
                 * with the target state's 'status' to make sure the 
                 * transition was successful.
                 * Note that we'll poll for up to 1ms (100 cycles of 10us) 
                 * before giving up.
                 */

                port = data->acpi_data.status_register.address;
                bit_width = data->acpi_data.status_register.bit_width;

                dprintk("Looking for 0x%08x from port 0x%04x\n",
                        (u32) data->acpi_data.states[state].status, port);

                for (i=0; i<100; i++) {
                        ret = acpi_processor_read_port(port, bit_width, &value);
                        if (ret) {      
                                dprintk("Invalid port width 0x%04x\n", bit_width);
                                retval = ret;
                                goto migrate_end;
                        }
                        if (value == (u32) data->acpi_data.states[state].status)
                                break;
                        udelay(10);
                }
        } else {
                i = 0;
                value = (u32) data->acpi_data.states[state].status;
        }

        /* notify cpufreq */
        cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);

        if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
                unsigned int tmp = cpufreq_freqs.new;
                cpufreq_freqs.new = cpufreq_freqs.old;
                cpufreq_freqs.old = tmp;
                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
                cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
                printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
                retval = -ENODEV;
                goto migrate_end;
        }

        dprintk("Transition successful after %d microseconds\n", i * 10);

        data->acpi_data.state = state;

        retval = 0;
migrate_end:
        set_cpus_allowed(current, saved_mask);
        return (retval);
}


static int
acpi_cpufreq_target (
        struct cpufreq_policy   *policy,
        unsigned int target_freq,
        unsigned int relation)
{
        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
        unsigned int next_state = 0;
        unsigned int result = 0;

        dprintk("acpi_cpufreq_setpolicy\n");

        result = cpufreq_frequency_table_target(policy,
                        data->freq_table,
                        target_freq,
                        relation,
                        &next_state);
        if (result)
                return (result);

        result = acpi_processor_set_performance (data, policy->cpu, next_state);

        return (result);
}


static int
acpi_cpufreq_verify (
        struct cpufreq_policy   *policy)
{
        unsigned int result = 0;
        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];

        dprintk("acpi_cpufreq_verify\n");

        result = cpufreq_frequency_table_verify(policy, 
                        data->freq_table);

        return (result);
}


static unsigned long
acpi_cpufreq_guess_freq (
        struct cpufreq_acpi_io  *data,
        unsigned int            cpu)
{
        if (cpu_khz) {
                /* search the closest match to cpu_khz */
                unsigned int i;
                unsigned long freq;
                unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;

                for (i=0; i < (data->acpi_data.state_count - 1); i++) {
                        freq = freqn;
                        freqn = data->acpi_data.states[i+1].core_frequency * 1000;
                        if ((2 * cpu_khz) > (freqn + freq)) {
                                data->acpi_data.state = i;
                                return (freq);
                        }
                }
                data->acpi_data.state = data->acpi_data.state_count - 1;
                return (freqn);
        } else
                /* assume CPU is at P0... */
                data->acpi_data.state = 0;
                return data->acpi_data.states[0].core_frequency * 1000;
        
}


/* 
 * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
 * of this driver
 * @perf: processor-specific acpi_io_data struct
 * @cpu: CPU being initialized
 *
 * To avoid issues with legacy OSes, some BIOSes require to be informed of
 * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC 
 * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
 * driver/acpi/processor.c
 */
static void 
acpi_processor_cpu_init_pdc_est(
                struct acpi_processor_performance *perf, 
                unsigned int cpu,
                struct acpi_object_list *obj_list
                )
{
        union acpi_object *obj;
        u32 *buf;
        struct cpuinfo_x86 *c = cpu_data + cpu;
        dprintk("acpi_processor_cpu_init_pdc_est\n");

        if (!cpu_has(c, X86_FEATURE_EST))
                return;

        /* Initialize pdc. It will be used later. */
        if (!obj_list)
                return;
                
        if (!(obj_list->count && obj_list->pointer))
                return;

        obj = obj_list->pointer;
        if ((obj->buffer.length == 12) && obj->buffer.pointer) {
                buf = (u32 *)obj->buffer.pointer;
                buf[0] = ACPI_PDC_REVISION_ID;
                buf[1] = 1;
                buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
                perf->pdc = obj_list;
        }
        return;
}
 

/* CPU specific PDC initialization */
static void 
acpi_processor_cpu_init_pdc(
                struct acpi_processor_performance *perf, 
                unsigned int cpu,
                struct acpi_object_list *obj_list
                )
{
        struct cpuinfo_x86 *c = cpu_data + cpu;
        dprintk("acpi_processor_cpu_init_pdc\n");
        perf->pdc = NULL;
        if (cpu_has(c, X86_FEATURE_EST))
                acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
        return;
}


static int
acpi_cpufreq_cpu_init (
        struct cpufreq_policy   *policy)
{
        unsigned int            i;
        unsigned int            cpu = policy->cpu;
        struct cpufreq_acpi_io  *data;
        unsigned int            result = 0;

        union acpi_object               arg0 = {ACPI_TYPE_BUFFER};
        u32                             arg0_buf[3];
        struct acpi_object_list         arg_list = {1, &arg0};

        dprintk("acpi_cpufreq_cpu_init\n");
        /* setup arg_list for _PDC settings */
        arg0.buffer.length = 12;
        arg0.buffer.pointer = (u8 *) arg0_buf;

        data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
        if (!data)
                return (-ENOMEM);

        acpi_io_data[cpu] = data;

        acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
        result = acpi_processor_register_performance(&data->acpi_data, cpu);
        data->acpi_data.pdc = NULL;

        if (result)
                goto err_free;

        if (is_const_loops_cpu(cpu)) {
                acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
        }

        /* capability check */
        if (data->acpi_data.state_count <= 1) {
                dprintk("No P-States\n");
                result = -ENODEV;
                goto err_unreg;
        }
        if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
            (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
                dprintk("Unsupported address space [%d, %d]\n",
                        (u32) (data->acpi_data.control_register.space_id),
                        (u32) (data->acpi_data.status_register.space_id));
                result = -ENODEV;
                goto err_unreg;
        }

        /* alloc freq_table */
        data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.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<data->acpi_data.state_count; i++) {
                if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
                        policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
        }
        policy->governor = CPUFREQ_DEFAULT_GOVERNOR;

        /* The current speed is unknown and not detectable by ACPI...  */
        policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);

        /* table init */
        for (i=0; i<=data->acpi_data.state_count; i++)
        {
                data->freq_table[i].index = i;
                if (i<data->acpi_data.state_count)
                        data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
                else
                        data->freq_table[i].frequency = CPUFREQ_TABLE_END;
        }

        result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
        if (result) {
                goto err_freqfree;
        }

        /* notify BIOS that we exist */
        acpi_processor_notify_smm(THIS_MODULE);

        printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
               cpu);
        for (i = 0; i < data->acpi_data.state_count; i++)
                dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
                        (i == data->acpi_data.state?'*':' '), i,
                        (u32) data->acpi_data.states[i].core_frequency,
                        (u32) data->acpi_data.states[i].power,
                        (u32) data->acpi_data.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(&data->acpi_data, cpu);
 err_free:
        kfree(data);
        acpi_io_data[cpu] = NULL;

        return (result);
}


static int
acpi_cpufreq_cpu_exit (
        struct cpufreq_policy   *policy)
{
        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];


        dprintk("acpi_cpufreq_cpu_exit\n");

        if (data) {
                cpufreq_frequency_table_put_attr(policy->cpu);
                acpi_io_data[policy->cpu] = NULL;
                acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
                kfree(data);
        }

        return (0);
}

static int
acpi_cpufreq_resume (
        struct cpufreq_policy   *policy)
{
        struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];


        dprintk("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,
        .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");