/*
  * Copyright (C) yajin 2008 <yajinzhou@gmail.com >
  *
  * This file is part of the virtualmips distribution.
  * See LICENSE file for terms of the license.
  */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <pthread.h>

#include "cpu.h"
#include "mips_memory.h"
#include "device.h"
#include "mips.h"
#include "mips_cp0.h"
#include "mips_exec.h"
#include "vm.h"

#define LOG_ENABLE 0

/*
 * Log a message for a CPU
 */
void cpu_log (cpu_mips_t * cpu, char *module, char *format, ...)
{
#if LOG_ENABLE
    char buffer[256];
    va_list ap;

    va_start (ap, format);
    snprintf (buffer, sizeof (buffer), "CPU%u: %s", cpu->id, module);
    vm_flog (cpu->vm, buffer, format, ap);
    va_end (ap);
#endif
}

/*
 * Start a CPU
 */
void cpu_start (cpu_mips_t * cpu)
{
    if (cpu) {
        cpu->state = CPU_STATE_RUNNING;
    }
}

/*
 * Stop a CPU
 */
void cpu_stop (cpu_mips_t * cpu)
{
    if (cpu) {
        cpu_log (cpu, "CPU_STATE", "Halting CPU (old state=%u)...\n",
            cpu->state);
        cpu->state = CPU_STATE_HALTED;
    }
}

void cpu_restart (cpu_mips_t * cpu)
{
    if (cpu) {
        cpu_log (cpu, "CPU_STATE", "Restartting CPU (old state=%u)...\n",
            cpu->state);
        cpu->state = CPU_STATE_RESTARTING;
    }
}

/*
 * Create a new CPU
 */
cpu_mips_t *cpu_create (vm_instance_t * vm, u_int type, u_int id)
{
    cpu_mips_t *cpu;

    cpu = malloc (sizeof (*cpu));
    if (!cpu)
        return NULL;

    memset (cpu, 0, sizeof (*cpu));
    cpu->vm = vm;
    cpu->id = id;
    cpu->type = type;
    cpu->state = CPU_STATE_SUSPENDED;
    cpu->vm = vm;
    mips_init (cpu);
    return cpu;
}

/*
 * Delete a CPU
 */
void cpu_delete (cpu_mips_t * cpu)
{
    if (cpu) {
        /* Stop activity of this CPU */
        cpu_stop (cpu);
        pthread_join (cpu->cpu_thread, NULL);
        mips_delete (cpu);
        free (cpu);
    }
}

/*
 * Find a CPU in a group given its ID
 */
cpu_mips_t *cpu_group_find_id (cpu_group_t * group, u_int id)
{
    cpu_mips_t *cpu;

    if (!group)
        return NULL;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        if (cpu->id == id)
            return cpu;

    return NULL;
}

/*
 * Find the highest CPU ID in a CPU group
 */
int cpu_group_find_highest_id (cpu_group_t * group, u_int * highest_id)
{
    cpu_mips_t *cpu;
    u_int max_id = 0;

    if (!group || group->cpu_list)
        return (-1);

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        if (cpu->id >= max_id)
            max_id = cpu->id;

    *highest_id = max_id;
    return (0);
}

/*
 * Add a CPU in a CPU group
 */
int cpu_group_add (cpu_group_t * group, cpu_mips_t * cpu)
{
    if (!group)
        return (-1);

    /* check that we don't already have a CPU with this id */
    if (cpu_group_find_id (group, cpu->id) != NULL) {
        fprintf (stderr, "cpu_group_add: CPU%u already present in group.\n",
            cpu->id);
        return (-1);
    }
    cpu->next = group->cpu_list;
    group->cpu_list = cpu;
    return (0);
}

/*
 * Create a new CPU group
 */
cpu_group_t *cpu_group_create (char *name)
{
    cpu_group_t *group;

    if (!(group = malloc (sizeof (*group))))
        return NULL;

    group->name = name;
    group->cpu_list = NULL;
    return group;
}

/*
 * Delete a CPU group
 */
void cpu_group_delete (cpu_group_t * group)
{
    cpu_mips_t *cpu, *next;

    if (group != NULL) {
        for (cpu = group->cpu_list; cpu; cpu = next) {
            next = cpu->next;
            cpu_delete (cpu);
        }
        free (group);
    }
}

/*
 * Rebuild the MTS subsystem for a CPU group
 */
int cpu_group_rebuild_mts (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu->mts_rebuild (cpu);

    return (0);
}

/*
 * Start all CPUs of a CPU group
 */
void cpu_group_start_all_cpu (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu_start (cpu);
}

/*
 * Stop all CPUs of a CPU group
 */
void cpu_group_stop_all_cpu (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu_stop (cpu);
}

/*
 * Set a state of all CPUs of a CPU group
 */
void cpu_group_set_state (cpu_group_t * group, u_int state)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu->state = state;
}

/*
 * Returns TRUE if all CPUs in a CPU group are inactive
 */
static int cpu_group_check_activity (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next) {
        if (!cpu->cpu_thread_running)
            continue;
        if (cpu->state == CPU_STATE_RUNNING)
            return (FALSE);
    }
    return (TRUE);
}

/*
 * Synchronize on CPUs (all CPUs must be inactive)
 */
int cpu_group_sync_state (cpu_group_t * group)
{
    m_tmcnt_t t1, t2;

    /* Check that CPU activity is really suspended */
    t1 = m_gettime ();

    while (!cpu_group_check_activity (group)) {
        t2 = m_gettime ();

        if (t2 > (t1 + 10000))
            return (-1);

        usleep (50000);
    }
    return (0);
}

/*
 * Save state of all CPUs
 */
int cpu_group_save_state (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu->prev_state = cpu->state;

    return (TRUE);
}

/*
 * Restore state of all CPUs
 */
int cpu_group_restore_state (cpu_group_t * group)
{
    cpu_mips_t *cpu;

    for (cpu = group->cpu_list; cpu; cpu = cpu->next)
        cpu->state = cpu->prev_state;

    return (TRUE);
}