代码如下图所示，最终操作的是msr daifset, #3 和 msr daifclr, #3 寄存器。
(include/linux/irqflags.h)
#define local_irq_enable() do {
raw_local_irq_enable(); } while (0)
#define local_irq_disable() do {
raw_local_irq_disable(); } while (0)
#define raw_local_irq_disable() arch_local_irq_disable()
#define raw_local_irq_enable() arch_local_irq_enable()
static inline void arch_local_irq_disable(void)
{
if (__irqflags_uses_pmr()) {
__pmr_local_irq_disable();
} else {
__daif_local_irq_disable();
}
}
static __always_inline void __daif_local_irq_disable(void)
{
barrier();
asm volatile("msr daifset, #3");
barrier();
}
30 static __always_inline void __daif_local_irq_enable(void)
31 {
32 barrier();
33 asm volatile("msr daifclr, #3");
34 barrier();
35 }