summaryrefslogtreecommitdiff
path: root/hw/xtensa_pic.c
blob: 653ded682011df035c963a367c322bcbc0476368 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/*
 * Copyright (c) 2011, Max Filippov, Open Source and Linux Lab.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Open Source and Linux Lab nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "hw.h"
#include "qemu-log.h"
#include "qemu-timer.h"

void xtensa_advance_ccount(CPUXtensaState *env, uint32_t d)
{
    uint32_t old_ccount = env->sregs[CCOUNT];

    env->sregs[CCOUNT] += d;

    if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT)) {
        int i;
        for (i = 0; i < env->config->nccompare; ++i) {
            if (env->sregs[CCOMPARE + i] - old_ccount <= d) {
                xtensa_timer_irq(env, i, 1);
            }
        }
    }
}

void check_interrupts(CPUXtensaState *env)
{
    int minlevel = xtensa_get_cintlevel(env);
    uint32_t int_set_enabled = env->sregs[INTSET] & env->sregs[INTENABLE];
    int level;

    /* If the CPU is halted advance CCOUNT according to the vm_clock time
     * elapsed since the moment when it was advanced last time.
     */
    if (env->halted) {
        int64_t now = qemu_get_clock_ns(vm_clock);

        xtensa_advance_ccount(env,
                muldiv64(now - env->halt_clock,
                    env->config->clock_freq_khz, 1000000));
        env->halt_clock = now;
    }
    for (level = env->config->nlevel; level > minlevel; --level) {
        if (env->config->level_mask[level] & int_set_enabled) {
            env->pending_irq_level = level;
            cpu_interrupt(env, CPU_INTERRUPT_HARD);
            qemu_log_mask(CPU_LOG_INT,
                    "%s level = %d, cintlevel = %d, "
                    "pc = %08x, a0 = %08x, ps = %08x, "
                    "intset = %08x, intenable = %08x, "
                    "ccount = %08x\n",
                    __func__, level, xtensa_get_cintlevel(env),
                    env->pc, env->regs[0], env->sregs[PS],
                    env->sregs[INTSET], env->sregs[INTENABLE],
                    env->sregs[CCOUNT]);
            return;
        }
    }
    env->pending_irq_level = 0;
    cpu_reset_interrupt(env, CPU_INTERRUPT_HARD);
}

static void xtensa_set_irq(void *opaque, int irq, int active)
{
    CPUXtensaState *env = opaque;

    if (irq >= env->config->ninterrupt) {
        qemu_log("%s: bad IRQ %d\n", __func__, irq);
    } else {
        uint32_t irq_bit = 1 << irq;

        if (active) {
            env->sregs[INTSET] |= irq_bit;
        } else if (env->config->interrupt[irq].inttype == INTTYPE_LEVEL) {
            env->sregs[INTSET] &= ~irq_bit;
        }

        check_interrupts(env);
    }
}

void xtensa_timer_irq(CPUXtensaState *env, uint32_t id, uint32_t active)
{
    qemu_set_irq(env->irq_inputs[env->config->timerint[id]], active);
}

void xtensa_rearm_ccompare_timer(CPUXtensaState *env)
{
    int i;
    uint32_t wake_ccount = env->sregs[CCOUNT] - 1;

    for (i = 0; i < env->config->nccompare; ++i) {
        if (env->sregs[CCOMPARE + i] - env->sregs[CCOUNT] <
                wake_ccount - env->sregs[CCOUNT]) {
            wake_ccount = env->sregs[CCOMPARE + i];
        }
    }
    env->wake_ccount = wake_ccount;
    qemu_mod_timer(env->ccompare_timer, env->halt_clock +
            muldiv64(wake_ccount - env->sregs[CCOUNT],
                1000000, env->config->clock_freq_khz));
}

static void xtensa_ccompare_cb(void *opaque)
{
    CPUXtensaState *env = opaque;

    if (env->halted) {
        env->halt_clock = qemu_get_clock_ns(vm_clock);
        xtensa_advance_ccount(env, env->wake_ccount - env->sregs[CCOUNT]);
        if (!cpu_has_work(env)) {
            env->sregs[CCOUNT] = env->wake_ccount + 1;
            xtensa_rearm_ccompare_timer(env);
        }
    }
}

void xtensa_irq_init(CPUXtensaState *env)
{
    env->irq_inputs = (void **)qemu_allocate_irqs(
            xtensa_set_irq, env, env->config->ninterrupt);
    if (xtensa_option_enabled(env->config, XTENSA_OPTION_TIMER_INTERRUPT) &&
            env->config->nccompare > 0) {
        env->ccompare_timer =
            qemu_new_timer_ns(vm_clock, &xtensa_ccompare_cb, env);
    }
}

void *xtensa_get_extint(CPUXtensaState *env, unsigned extint)
{
    if (extint < env->config->nextint) {
        unsigned irq = env->config->extint[extint];
        return env->irq_inputs[irq];
    } else {
        qemu_log("%s: trying to acquire invalid external interrupt %d\n",
                __func__, extint);
        return NULL;
    }
}