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