hw/nios2/cpu_pic.c

   1 /*
   2  * Altera Nios2 CPU PIC
   3  *
   4  * Copyright (c) 2016 Marek Vasut <marek.vasut@gmail.com>
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see
  18  * <http://www.gnu.org/licenses/lgpl-2.1.html>
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "qapi/error.h"
  23 #include "qemu-common.h"
  24 #include "cpu.h"
  25
  26 #include "qemu/config-file.h"
  27
  28 #include "boot.h"
  29
  30 static void nios2_pic_cpu_handler(void *opaque, int irq, int level)
  31 {
  32     Nios2CPU *cpu = opaque;
  33     CPUNios2State *env = &cpu->env;
  34     CPUState *cs = CPU(cpu);
  35     int type = irq ? CPU_INTERRUPT_NMI : CPU_INTERRUPT_HARD;
  36
  37     if (type == CPU_INTERRUPT_HARD) {
  38         env->irq_pending = level;
  39
  40         if (level && (env->regs[CR_STATUS] & CR_STATUS_PIE)) {
  41             env->irq_pending = 0;
  42             cpu_interrupt(cs, type);
  43         } else if (!level) {
  44             env->irq_pending = 0;
  45             cpu_reset_interrupt(cs, type);
  46         }
  47     } else {
  48         if (level) {
  49             cpu_interrupt(cs, type);
  50         } else {
  51             cpu_reset_interrupt(cs, type);
  52         }
  53     }
  54 }
  55
  56 void nios2_check_interrupts(CPUNios2State *env)
  57 {
  58     Nios2CPU *cpu = nios2_env_get_cpu(env);
  59     CPUState *cs = CPU(cpu);
  60
  61     if (env->irq_pending) {
  62         env->irq_pending = 0;
  63         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
  64     }
  65 }
  66
  67 qemu_irq *nios2_cpu_pic_init(Nios2CPU *cpu)
  68 {
  69     return qemu_allocate_irqs(nios2_pic_cpu_handler, cpu, 2);
  70 }