关于cortex-a9多核情况下interrupt_disable定义

发布于 2019-03-23 22:03:54 浏览：3351 订阅该版

首先申明下，我整准备把rtt3.0移植到imx6q上，别问为什么不用LINUX :lol
在rhtw.h中
```c
#ifdef RT_USING_SMP
rt_base_t rt_hw_local_irq_disable();
void rt_hw_local_irq_enable(rt_base_t level);
#define rt_hw_interrupt_disable rt_cpus_lock
#define rt_hw_interrupt_enable rt_cpus_unlock
```

在cpu.c中，调用了rt_hw_local_irq_enable
```c
rt_base_t rt_cpus_lock(void)
{
    rt_base_t level;
    struct rt_cpu* pcpu;
    level = rt_hw_local_irq_disable();
    pcpu = rt_cpu_self();
    if (pcpu->current_thread != RT_NULL)
    {
        if (pcpu->current_thread->cpus_lock_nest++ == 0)
        {
            pcpu->current_thread->scheduler_lock_nest++;
            rt_hw_spin_lock(&_cpus_lock);
        }
    }
    return level;
}
RTM_EXPORT(rt_cpus_lock);
/**
 * This function will restore all cpus's scheduler and restore local irq.
 */
void rt_cpus_unlock(rt_base_t level)
{
    struct rt_cpu* pcpu = rt_cpu_self();
    if (pcpu->current_thread != RT_NULL)
    {
        if (--pcpu->current_thread->cpus_lock_nest == 0)
        {
            pcpu->current_thread->scheduler_lock_nest--;
            rt_hw_spin_unlock(&_cpus_lock);
        }
    }
    rt_hw_local_irq_enable(level);
```

但是rt_hw_local_irq_enable并没有明确定义，只是在`context-gcc.s`中又写了一句
```c
#ifdef RT_USING_SMP
#define rt_hw_interrupt_disable rt_hw_local_irq_disable
#define rt_hw_interrupt_enable  rt_hw_local_irq_enable
#endif
```

然后这汇编中呢又定义了rt_hw_interrupt_disable、rt_hw_interrupt_enable，和上面两个文件产生了冲突，因为rthw.h、cpu.c两个文件作为内核文件时必须调用的，而context.s除非被放弃，这时候就得想法子去定义下rt_hw_local_irq_disable、rt_hw_local_irq_enable，这个地方很困惑，有作者来解答么？

```c
rt_hw_interrupt_disable:
    mrs r0, cpsr
    cpsid i
    bx  lr
/*
 * void rt_hw_interrupt_enable(rt_base_t level);
 */

rt_hw_interrupt_enable:
    msr cpsr, r0
    bx  lr
```