linux/arch/riscv/kernel/irq.c

60 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2012 Regents of the University of California
* Copyright (C) 2017 SiFive
* Copyright (C) 2018 Christoph Hellwig
*/
#include <linux/interrupt.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
/*
* Possible interrupt causes:
*/
#define INTERRUPT_CAUSE_SOFTWARE 1
#define INTERRUPT_CAUSE_TIMER 5
#define INTERRUPT_CAUSE_EXTERNAL 9
/*
* The high order bit of the trap cause register is always set for
* interrupts, which allows us to differentiate them from exceptions
* quickly. The INTERRUPT_CAUSE_* macros don't contain that bit, so we
* need to mask it off.
*/
#define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause)
{
struct pt_regs *old_regs = set_irq_regs(regs);
irq_enter();
switch (cause & ~INTERRUPT_CAUSE_FLAG) {
case INTERRUPT_CAUSE_TIMER:
riscv_timer_interrupt();
break;
#ifdef CONFIG_SMP
case INTERRUPT_CAUSE_SOFTWARE:
/*
* We only use software interrupts to pass IPIs, so if a non-SMP
* system gets one, then we don't know what to do.
*/
riscv_software_interrupt();
break;
#endif
case INTERRUPT_CAUSE_EXTERNAL:
handle_arch_irq(regs);
break;
default:
panic("unexpected interrupt cause");
}
irq_exit();
set_irq_regs(old_regs);
}
void __init init_IRQ(void)
{
irqchip_init();
}