hw/xtensa_pic.c

   1 /*
   2  * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *     * Redistributions of source code must retain the above copyright
   8  *       notice, this list of conditions and the following disclaimer.
   9  *     * Redistributions in binary form must reproduce the above copyright
  10  *       notice, this list of conditions and the following disclaimer in the
  11  *       documentation and/or other materials provided with the distribution.
  12  *     * Neither the name of the Open Source and Linux Lab nor the
  13  *       names of its contributors may be used to endorse or promote products
  14  *       derived from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
  20  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  21  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  23  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  25  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "hw.h"
  29 #include "qemu/log.h"
  30 #include "qemu/timer.h"
  31
  32 void xtensa_advance_ccount(CPUXtensaState *env, uint32_t d)
  33 {
  34     uint32_t old_ccount = env->sregs[CCOUNT];
  35
  36     env->sregs[CCOUNT] += d;
  37
  38     if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT)) {
  39         int i;
  40         for (i = 0; i < env->config->nccompare; ++i) {
  41             if (env->sregs[CCOMPARE + i] - old_ccount <= d) {
  42                 xtensa_timer_irq(env, i, 1);
  43             }
  44         }
  45     }
  46 }
  47
  48 void check_interrupts(CPUXtensaState *env)
  49 {
  50     int minlevel = xtensa_get_cintlevel(env);
  51     uint32_t int_set_enabled = env->sregs[INTSET] & env->sregs[INTENABLE];
  52     int level;
  53
  54     /* If the CPU is halted advance CCOUNT according to the vm_clock time
  55      * elapsed since the moment when it was advanced last time.
  56      */
  57     if (env->halted) {
  58         int64_t now = qemu_get_clock_ns(vm_clock);
  59
  60         xtensa_advance_ccount(env,
  61                 muldiv64(now - env->halt_clock,
  62                     env->config->clock_freq_khz, 1000000));
  63         env->halt_clock = now;
  64     }
  65     for (level = env->config->nlevel; level > minlevel; --level) {
  66         if (env->config->level_mask[level] & int_set_enabled) {
  67             env->pending_irq_level = level;
  68             cpu_interrupt(env, CPU_INTERRUPT_HARD);
  69             qemu_log_mask(CPU_LOG_INT,
  70                     "%s level = %d, cintlevel = %d, "
  71                     "pc = %08x, a0 = %08x, ps = %08x, "
  72                     "intset = %08x, intenable = %08x, "
  73                     "ccount = %08x\n",
  74                     __func__, level, xtensa_get_cintlevel(env),
  75                     env->pc, env->regs[0], env->sregs[PS],
  76                     env->sregs[INTSET], env->sregs[INTENABLE],
  77                     env->sregs[CCOUNT]);
  78             return;
  79         }
  80     }
  81     env->pending_irq_level = 0;
  82     cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
  83 }
  84
  85 static void xtensa_set_irq(void *opaque, int irq, int active)
  86 {
  87     CPUXtensaState *env = opaque;
  88
  89     if (irq >= env->config->ninterrupt) {
  90         qemu_log("%s: bad IRQ %d\n", __func__, irq);
  91     } else {
  92         uint32_t irq_bit = 1 << irq;
  93
  94         if (active) {
  95             env->sregs[INTSET] |= irq_bit;
  96         } else if (env->config->interrupt[irq].inttype == INTTYPE_LEVEL) {
  97             env->sregs[INTSET] &= ~irq_bit;
  98         }
  99
 100         check_interrupts(env);
 101     }
 102 }
 103
 104 void xtensa_timer_irq(CPUXtensaState *env, uint32_t id, uint32_t active)
 105 {
 106     qemu_set_irq(env->irq_inputs[env->config->timerint[id]], active);
 107 }
 108
 109 void xtensa_rearm_ccompare_timer(CPUXtensaState *env)
 110 {
 111     int i;
 112     uint32_t wake_ccount = env->sregs[CCOUNT] - 1;
 113
 114     for (i = 0; i < env->config->nccompare; ++i) {
 115         if (env->sregs[CCOMPARE + i] - env->sregs[CCOUNT] <
 116                 wake_ccount - env->sregs[CCOUNT]) {
 117             wake_ccount = env->sregs[CCOMPARE + i];
 118         }
 119     }
 120     env->wake_ccount = wake_ccount;
 121     qemu_mod_timer(env->ccompare_timer, env->halt_clock +
 122             muldiv64(wake_ccount - env->sregs[CCOUNT],
 123                 1000000, env->config->clock_freq_khz));
 124 }
 125
 126 static void xtensa_ccompare_cb(void *opaque)
 127 {
 128     XtensaCPU *cpu = opaque;
 129     CPUXtensaState *env = &cpu->env;
 130
 131     if (env->halted) {
 132         env->halt_clock = qemu_get_clock_ns(vm_clock);
 133         xtensa_advance_ccount(env, env->wake_ccount - env->sregs[CCOUNT]);
 134         if (!cpu_has_work(CPU(cpu))) {
 135             env->sregs[CCOUNT] = env->wake_ccount + 1;
 136             xtensa_rearm_ccompare_timer(env);
 137         }
 138     }
 139 }
 140
 141 void xtensa_irq_init(CPUXtensaState *env)
 142 {
 143     XtensaCPU *cpu = xtensa_env_get_cpu(env);
 144
 145     env->irq_inputs = (void **)qemu_allocate_irqs(
 146             xtensa_set_irq, env, env->config->ninterrupt);
 147     if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT) &&
 148             env->config->nccompare > 0) {
 149         env->ccompare_timer =
 150             qemu_new_timer_ns(vm_clock, &xtensa_ccompare_cb, cpu);
 151     }
 152 }
 153
 154 void *xtensa_get_extint(CPUXtensaState *env, unsigned extint)
 155 {
 156     if (extint < env->config->nextint) {
 157         unsigned irq = env->config->extint[extint];
 158         return env->irq_inputs[irq];
 159     } else {
 160         qemu_log("%s: trying to acquire invalid external interrupt %d\n",
 161                 __func__, extint);
 162         return NULL;
 163     }
 164 }