[CPUFREQ][2/8] acpi: reorganize code to make MSR support addition easier

[linux-2.6/mini2440.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c

/*
 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
 *
 *  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/sched.h>        /* current */
#include <linux/dmi.h>

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

#include <asm/io.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/delay.h>
#include <asm/uaccess.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 acpi_cpufreq_data {
        struct acpi_processor_performance       *acpi_data;
        struct cpufreq_frequency_table          *freq_table;
        unsigned int                            resume;
};

static struct acpi_cpufreq_data *drv_data[NR_CPUS];
static struct acpi_processor_performance        *acpi_perf_data[NR_CPUS];

static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;

static unsigned extract_freq(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 void wrport(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);
        }
}

static void rdport(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);
        }
}

struct io_addr {
        u16 port;
        u8 bit_width;
};

struct drv_cmd {
        cpumask_t mask;
        struct io_addr addr;
        u32 val;
};

static void do_drv_read(struct drv_cmd *cmd)
{
        rdport(cmd->addr.port, cmd->addr.bit_width, &cmd->val);
        return;
}

static void do_drv_write(struct drv_cmd *cmd)
{
        wrport(cmd->addr.port, cmd->addr.bit_width, cmd->val);
        return;
}

static inline void drv_read(struct drv_cmd *cmd)
{
        cpumask_t       saved_mask = current->cpus_allowed;
        cmd->val = 0;

        set_cpus_allowed(current, cmd->mask);
        do_drv_read(cmd);
        set_cpus_allowed(current, saved_mask);

}

static void drv_write(struct drv_cmd *cmd)
{
        cpumask_t       saved_mask = current->cpus_allowed;
        unsigned int    i;

        for_each_cpu_mask(i, cmd->mask) {
                set_cpus_allowed(current, cpumask_of_cpu(i));
                do_drv_write(cmd);
        }

        set_cpus_allowed(current, saved_mask);
        return;
}

static u32 get_cur_val(cpumask_t mask)
{
        struct acpi_processor_performance       *perf;
        struct drv_cmd                          cmd;

        if (unlikely(cpus_empty(mask)))
                return 0;

        perf = drv_data[first_cpu(mask)]->acpi_data;
        cmd.addr.port = perf->control_register.address;
        cmd.addr.bit_width = perf->control_register.bit_width;
        cmd.mask = mask;

        drv_read(&cmd);

        dprintk("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 = drv_data[cpu];
        unsigned int                            freq;

        dprintk("get_cur_freq_on_cpu (%d)\n", cpu);

        if (unlikely(data == NULL ||
                     data->acpi_data == NULL ||
                     data->freq_table == NULL)) {
                return 0;
        }

        freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
        dprintk("cur freq = %u\n", freq);

        return freq;
}

static unsigned int check_freqs(cpumask_t 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 = drv_data[policy->cpu];
        struct acpi_processor_performance       *perf;
        struct cpufreq_freqs                    freqs;
        cpumask_t                               online_policy_cpus;
        struct drv_cmd                          cmd;
        unsigned int                            next_state = 0;
        unsigned int                            next_perf_state = 0;
        unsigned int                            i;
        int                                     result = 0;

        dprintk("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))
                return -ENODEV;

#ifdef CONFIG_HOTPLUG_CPU
        /* cpufreq holds the hotplug lock, so we are safe from here on */
        cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
#else
        online_policy_cpus = policy->cpus;
#endif

        cmd.val = get_cur_val(online_policy_cpus);
        freqs.old = extract_freq(cmd.val, data);
        freqs.new = data->freq_table[next_state].frequency;
        next_perf_state = data->freq_table[next_state].index;
        if (freqs.new == freqs.old) {
                if (unlikely(data->resume)) {
                        dprintk("Called after resume, resetting to P%d\n", next_perf_state);
                        data->resume = 0;
                } else {
                        dprintk("Already at target state (P%d)\n", next_perf_state);
                        return 0;
                }
        }

        cmd.addr.port = perf->control_register.address;
        cmd.addr.bit_width = perf->control_register.bit_width;
        cmd.val = (u32) perf->states[next_perf_state].control;

        cpus_clear(cmd.mask);

        if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
                cmd.mask = online_policy_cpus;
        else
                cpu_set(policy->cpu, cmd.mask);

        for_each_cpu_mask(i, cmd.mask) {
                freqs.cpu = i;
                cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
        }

        drv_write(&cmd);

        if (acpi_pstate_strict) {
                if (!check_freqs(cmd.mask, freqs.new, data)) {
                        dprintk("acpi_cpufreq_target failed (%d)\n",
                                        policy->cpu);
                        return -EAGAIN;
                }
        }

        for_each_cpu_mask(i, cmd.mask) {
                freqs.cpu = i;
                cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
        }
        perf->state = next_perf_state;

        return result;
}


static int
acpi_cpufreq_verify (
        struct cpufreq_policy   *policy)
{
        struct acpi_cpufreq_data *data = drv_data[policy->cpu];

        dprintk("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;
        }
}


/*
 * 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 acpi_cpufreq_early_init(void)
{
        struct acpi_processor_performance       *data;
        cpumask_t                               covered;
        unsigned int                            i, j;

        dprintk("acpi_cpufreq_early_init\n");

        for_each_possible_cpu(i) {
                data = kzalloc(sizeof(struct acpi_processor_performance), 
                        GFP_KERNEL);
                if (!data) {
                        for_each_cpu_mask(j, covered) {
                                kfree(acpi_perf_data[j]);
                                acpi_perf_data[j] = NULL;
                        }
                        return (-ENOMEM);
                }
                acpi_perf_data[i] = data;
                cpu_set(i, covered);
        }

        /* Do initialization in ACPI core */
        acpi_processor_preregister_performance(acpi_perf_data);
        return 0;
}

/*
 * 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(struct dmi_system_id *d)
{
        bios_with_sw_any_bug = 1;
        return 0;
}

static 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_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;

        dprintk("acpi_cpufreq_cpu_init\n");

        if (!acpi_perf_data[cpu])
                return (-ENODEV);

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

        data->acpi_data = acpi_perf_data[cpu];
        drv_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) {
                policy->cpus = perf->shared_cpu_map;
        }

#ifdef CONFIG_SMP
        dmi_check_system(sw_any_bug_dmi_table);
        if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
                policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
                policy->cpus = cpu_core_map[cpu];
        }
#endif

        /* capability check */
        if (perf->state_count <= 1) {
                dprintk("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:
                dprintk("SYSTEM IO addr space\n");
                break;
            default:
                dprintk("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;
        }
        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<perf->state_count; i++)
        {
                if ( i > 0 && perf->states[i].core_frequency ==
                                perf->states[i - 1].core_frequency)
                        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[perf->state_count].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);

        dprintk("CPU%u - ACPI performance management activated.\n", cpu);
        for (i = 0; i < perf->state_count; i++)
                dprintk("     %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);
        drv_data[cpu] = NULL;

        return (result);
}


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


        dprintk("acpi_cpufreq_cpu_exit\n");

        if (data) {
                cpufreq_frequency_table_put_attr(policy->cpu);
                drv_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 acpi_cpufreq_data *data = drv_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,
        .get    = get_cur_freq_on_cpu,
        .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)
{
        dprintk("acpi_cpufreq_init\n");

        acpi_cpufreq_early_init();

        return cpufreq_register_driver(&acpi_cpufreq_driver);
}


static void __exit
acpi_cpufreq_exit (void)
{
        unsigned int    i;
        dprintk("acpi_cpufreq_exit\n");

        cpufreq_unregister_driver(&acpi_cpufreq_driver);

        for_each_possible_cpu(i) {
                kfree(acpi_perf_data[i]);
                acpi_perf_data[i] = NULL;
        }
        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");