DragonOS/kernel/smp/smp.c

#include "smp.h"
#include <common/kprint.h>
#include <driver/interrupt/apic/apic.h>
#include <exception/gate.h>
#include <common/cpu.h>
#include <mm/slab.h>
#include <process/process.h>
#include <common/spinlock.h>

#include <sched/sched.h>

#include "ipi.h"

void ipi_0xc8_handler(uint64_t irq_num, uint64_t param, struct pt_regs *regs); // 由BSP转发的HPET中断处理函数

static spinlock_t multi_core_starting_lock; // 多核启动锁

static struct acpi_Processor_Local_APIC_Structure_t *proc_local_apic_structs[MAX_SUPPORTED_PROCESSOR_NUM];
static uint32_t total_processor_num = 0;
int current_starting_cpu = 0;

int num_cpu_started = 1;

void smp_init()
{
    spin_init(&multi_core_starting_lock); // 初始化多核启动锁
    ul tmp_vaddr[MAX_SUPPORTED_PROCESSOR_NUM] = {0};

    apic_get_ics(ACPI_ICS_TYPE_PROCESSOR_LOCAL_APIC, tmp_vaddr, &total_processor_num);

    // kdebug("processor num=%d", total_processor_num);
    for (int i = 0; i < total_processor_num; ++i)
    {
        io_mfence();
        proc_local_apic_structs[i] = (struct acpi_Processor_Local_APIC_Structure_t *)(tmp_vaddr[i]);
    }

    //*(uchar *)0x20000 = 0xf4; // 在内存的0x20000处写入HLT指令(AP处理器会执行物理地址0x20000的代码)
    // 将引导程序复制到物理地址0x20000处
    memcpy((unsigned char *)phys_2_virt(0x20000), _apu_boot_start, (unsigned long)&_apu_boot_end - (unsigned long)&_apu_boot_start);
    io_mfence();
    // 设置多核IPI中断门
    for (int i = 200; i < 210; ++i)
        set_intr_gate(i, 0, SMP_interrupt_table[i - 200]);
    memset((void *)SMP_IPI_desc, 0, sizeof(irq_desc_t) * SMP_IRQ_NUM);
    
    io_mfence();

    // 注册接收bsp处理器的hpet中断转发的处理函数
    ipi_regiserIPI(0xc8, NULL, &ipi_0xc8_handler, NULL, NULL, "IPI 0xc8");
    io_mfence();
    ipi_send_IPI(DEST_PHYSICAL, IDLE, ICR_LEVEL_DE_ASSERT, EDGE_TRIGGER, 0x00, ICR_INIT, ICR_ALL_EXCLUDE_Self, true, 0x00);
    kdebug("total_processor_num=%d", total_processor_num);
    for (int i = 1; i < total_processor_num; ++i) // i从1开始，不初始化bsp
    {
        io_mfence();
        if (proc_local_apic_structs[i]->ACPI_Processor_UID == 0)
            --total_processor_num;
        io_mfence();
        if (proc_local_apic_structs[i]->local_apic_id > total_processor_num)
        {
            --total_processor_num;
            continue;
        }
        kdebug("[core %d] acpi processor UID=%d, APIC ID=%d, flags=%#010lx", i, proc_local_apic_structs[i]->ACPI_Processor_UID, proc_local_apic_structs[i]->local_apic_id, proc_local_apic_structs[i]->flags);
        io_mfence();
        spin_lock(&multi_core_starting_lock);
        preempt_enable(); // 由于ap处理器的pcb与bsp的不同，因此ap处理器放锁时，bsp的自旋锁持有计数不会发生改变,需要手动恢复preempt count
        current_starting_cpu = proc_local_apic_structs[i]->local_apic_id;
        io_mfence();
        // 为每个AP处理器分配栈空间
        cpu_core_info[current_starting_cpu].stack_start = (uint64_t)kmalloc(STACK_SIZE, 0) + STACK_SIZE;
        cpu_core_info[current_starting_cpu].ist_stack_start = (uint64_t)(kmalloc(STACK_SIZE, 0)) + STACK_SIZE;
        io_mfence();
        memset((void *)cpu_core_info[current_starting_cpu].stack_start - STACK_SIZE, 0, STACK_SIZE);
        memset((void *)cpu_core_info[current_starting_cpu].ist_stack_start - STACK_SIZE, 0, STACK_SIZE);
        io_mfence();

        // 设置ap处理器的中断栈及内核栈中的cpu_id
        ((struct process_control_block *)(cpu_core_info[current_starting_cpu].stack_start - STACK_SIZE))->cpu_id = proc_local_apic_structs[i]->local_apic_id;
        ((struct process_control_block *)(cpu_core_info[current_starting_cpu].ist_stack_start - STACK_SIZE))->cpu_id = proc_local_apic_structs[i]->local_apic_id;

        cpu_core_info[current_starting_cpu].tss_vaddr = (uint64_t)&initial_tss[current_starting_cpu];

        memset(&initial_tss[current_starting_cpu], 0, sizeof(struct tss_struct));

        set_tss_descriptor(10 + (current_starting_cpu * 2), (void *)(cpu_core_info[current_starting_cpu].tss_vaddr));
        io_mfence();
        set_tss64((uint *)cpu_core_info[current_starting_cpu].tss_vaddr, cpu_core_info[current_starting_cpu].stack_start, cpu_core_info[current_starting_cpu].stack_start, cpu_core_info[current_starting_cpu].stack_start,
                  cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start, cpu_core_info[current_starting_cpu].ist_stack_start);
        io_mfence();
        // 连续发送两次start-up IPI
        ipi_send_IPI(DEST_PHYSICAL, IDLE, ICR_LEVEL_DE_ASSERT, EDGE_TRIGGER, 0x20, ICR_Start_up, ICR_No_Shorthand, true, proc_local_apic_structs[i]->local_apic_id);
        io_mfence();
        ipi_send_IPI(DEST_PHYSICAL, IDLE, ICR_LEVEL_DE_ASSERT, EDGE_TRIGGER, 0x20, ICR_Start_up, ICR_No_Shorthand, true, proc_local_apic_structs[i]->local_apic_id);
    }
    io_mfence();
    while (num_cpu_started != total_processor_num)
        pause();

    kinfo("Cleaning page table remapping...\n");

    // 由于ap处理器初始化过程需要用到0x00处的地址，因此初始化完毕后才取消内存地址的重映射
    uint64_t *global_CR3 = get_CR3();
    for (int i = 0; i < 256; ++i)
    {
        io_mfence();
        *(ul *)(phys_2_virt(global_CR3) + i) = 0UL;
    }
    kdebug("init proc's preempt_count=%ld", current_pcb->preempt_count);
    kinfo("Successfully cleaned page table remapping!\n");
}

/**
 * @brief AP处理器启动后执行的第一个函数
 *
 */
void smp_ap_start()
{

    //  切换栈基地址
    //  uint64_t stack_start = (uint64_t)kmalloc(STACK_SIZE, 0) + STACK_SIZE;
    __asm__ __volatile__("movq %0, %%rbp \n\t" ::"m"(cpu_core_info[current_starting_cpu].stack_start)
                         : "memory");
    __asm__ __volatile__("movq %0, %%rsp \n\t" ::"m"(cpu_core_info[current_starting_cpu].stack_start)
                         : "memory");
    /*
        __asm__ __volatile__("movq %0, %%rbp \n\t" ::"m"(stack_start)
                             : "memory");
        __asm__ __volatile__("movq %0, %%rsp \n\t" ::"m"(stack_start)
                             : "memory");*/
    ksuccess("AP core successfully started!");
    io_mfence();
    ++num_cpu_started;

    kdebug("current cpu = %d", current_starting_cpu);

    apic_init_ap_core_local_apic();

    // ============ 为ap处理器初始化IDLE进程 =============
    memset(current_pcb, 0, sizeof(struct process_control_block));

    barrier();
    current_pcb->state = PROC_RUNNING;
    current_pcb->flags = PF_KTHREAD;
    current_pcb->mm = &initial_mm;

    list_init(&current_pcb->list);
    current_pcb->addr_limit = KERNEL_BASE_LINEAR_ADDR;
    current_pcb->priority = 2;
    current_pcb->virtual_runtime = 0;

    current_pcb->thread = (struct thread_struct *)(current_pcb + 1); // 将线程结构体放置在pcb后方
    current_pcb->thread->rbp = _stack_start;
    current_pcb->thread->rsp = _stack_start;
    current_pcb->thread->fs = KERNEL_DS;
    current_pcb->thread->gs = KERNEL_DS;
    current_pcb->cpu_id = current_starting_cpu;

    initial_proc[proc_current_cpu_id] = current_pcb;
    barrier();
    load_TR(10 + current_starting_cpu * 2);
    current_pcb->preempt_count = 0;

    // kdebug("IDT_addr = %#018lx", phys_2_virt(IDT_Table));
    io_mfence();
    spin_unlock(&multi_core_starting_lock);
    preempt_disable(); // 由于ap处理器的pcb与bsp的不同，因此ap处理器放锁时，需要手动恢复preempt count
    io_mfence();
    sti();

    while (1)
        hlt();

    /*
        if (proc_current_cpu_id == 1)
            process_init();
            */
    while (1)
    {
        printk_color(BLACK, WHITE, "CPU:%d IDLE process.\n", proc_current_cpu_id);
    }
    while (1) // 这里要循环hlt，原因是当收到中断后，核心会被唤醒，处理完中断之后不会自动hlt
        hlt();
}

// 由BSP转发的HPET中断处理函数
void ipi_0xc8_handler(uint64_t irq_num, uint64_t param, struct pt_regs *regs)
{
    sched_update_jiffies();
}