hw/xtensa/pic_cpu.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 "qemu/osdep.h"
  29 #include "cpu.h"
  30 #include "hw/hw.h"
  31 #include "qemu/log.h"
  32 #include "qemu/timer.h"
  33
  34 void xtensa_advance_ccount(CPUXtensaState *env, uint32_t d)
  35 {
  36     uint32_t old_ccount = env->sregs[CCOUNT] + 1;
  37
  38     env->sregs[CCOUNT] += d;
  39
  40     if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT)) {
  41         int i;
  42         for (i = 0; i < env->config->nccompare; ++i) {
  43             if (env->sregs[CCOMPARE + i] - old_ccount < d) {
  44                 xtensa_timer_irq(env, i, 1);
  45             }
  46         }
  47     }
  48 }
  49
  50 void check_interrupts(CPUXtensaState *env)
  51 {
  52     CPUState *cs = CPU(xtensa_env_get_cpu(env));
  53     int minlevel = xtensa_get_cintlevel(env);
  54     uint32_t int_set_enabled = env->sregs[INTSET] & env->sregs[INTENABLE];
  55     int level;
  56
  57     /* If the CPU is halted advance CCOUNT according to the QEMU_CLOCK_VIRTUAL time
  58      * elapsed since the moment when it was advanced last time.
  59      */
  60     if (cs->halted) {
  61         int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
  62
  63         xtensa_advance_ccount(env,
  64                 muldiv64(now - env->halt_clock,
  65                     env->config->clock_freq_khz, 1000000));
  66         env->halt_clock = now;
  67     }
  68     for (level = env->config->nlevel; level > minlevel; --level) {
  69         if (env->config->level_mask[level] & int_set_enabled) {
  70             env->pending_irq_level = level;
  71             cpu_interrupt(cs, CPU_INTERRUPT_HARD);
  72             qemu_log_mask(CPU_LOG_INT,
  73                     "%s level = %d, cintlevel = %d, "
  74                     "pc = %08x, a0 = %08x, ps = %08x, "
  75                     "intset = %08x, intenable = %08x, "
  76                     "ccount = %08x\n",
  77                     __func__, level, xtensa_get_cintlevel(env),
  78                     env->pc, env->regs[0], env->sregs[PS],
  79                     env->sregs[INTSET], env->sregs[INTENABLE],
  80                     env->sregs[CCOUNT]);
  81             return;
  82         }
  83     }
  84     env->pending_irq_level = 0;
  85     cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
  86 }
  87
  88 static void xtensa_set_irq(void *opaque, int irq, int active)
  89 {
  90     CPUXtensaState *env = opaque;
  91
  92     if (irq >= env->config->ninterrupt) {
  93         qemu_log("%s: bad IRQ %d\n", __func__, irq);
  94     } else {
  95         uint32_t irq_bit = 1 << irq;
  96
  97         if (active) {
  98             env->sregs[INTSET] |= irq_bit;
  99         } else if (env->config->interrupt[irq].inttype == INTTYPE_LEVEL) {
 100             env->sregs[INTSET] &= ~irq_bit;
 101         }
 102
 103         check_interrupts(env);
 104     }
 105 }
 106
 107 void xtensa_timer_irq(CPUXtensaState *env, uint32_t id, uint32_t active)
 108 {
 109     qemu_set_irq(env->irq_inputs[env->config->timerint[id]], active);
 110 }
 111
 112 void xtensa_rearm_ccompare_timer(CPUXtensaState *env)
 113 {
 114     int i;
 115     uint32_t wake_ccount = env->sregs[CCOUNT] - 1;
 116
 117     for (i = 0; i < env->config->nccompare; ++i) {
 118         if (env->sregs[CCOMPARE + i] - env->sregs[CCOUNT] <
 119                 wake_ccount - env->sregs[CCOUNT]) {
 120             wake_ccount = env->sregs[CCOMPARE + i];
 121         }
 122     }
 123     env->wake_ccount = wake_ccount;
 124     timer_mod(env->ccompare_timer, env->halt_clock +
 125             (uint64_t)(wake_ccount - env->sregs[CCOUNT]) *
 126             1000000 / env->config->clock_freq_khz);
 127 }
 128
 129 static void xtensa_ccompare_cb(void *opaque)
 130 {
 131     XtensaCPU *cpu = opaque;
 132     CPUXtensaState *env = &cpu->env;
 133     CPUState *cs = CPU(cpu);
 134
 135     if (cs->halted) {
 136         env->halt_clock = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 137         xtensa_advance_ccount(env, env->wake_ccount - env->sregs[CCOUNT]);
 138         if (!cpu_has_work(cs)) {
 139             env->sregs[CCOUNT] = env->wake_ccount + 1;
 140             xtensa_rearm_ccompare_timer(env);
 141         }
 142     }
 143 }
 144
 145 void xtensa_irq_init(CPUXtensaState *env)
 146 {
 147     XtensaCPU *cpu = xtensa_env_get_cpu(env);
 148
 149     env->irq_inputs = (void **)qemu_allocate_irqs(
 150             xtensa_set_irq, env, env->config->ninterrupt);
 151     if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT) &&
 152             env->config->nccompare > 0) {
 153         env->ccompare_timer =
 154             timer_new_ns(QEMU_CLOCK_VIRTUAL, &xtensa_ccompare_cb, cpu);
 155     }
 156 }
 157
 158 void *xtensa_get_extint(CPUXtensaState *env, unsigned extint)
 159 {
 160     if (extint < env->config->nextint) {
 161         unsigned irq = env->config->extint[extint];
 162         return env->irq_inputs[irq];
 163     } else {
 164         qemu_log("%s: trying to acquire invalid external interrupt %d\n",
 165                 __func__, extint);
 166         return NULL;
 167     }
 168 }