m68k: add an interrupt controller

A (generic) copy of the GLUE device we already have for q800 to use with
the m68k-virt machine.
The q800 one would disappear in the future as q800 uses actually the djMEMC
controller.

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210312214145.2936082-4-laurent@vivier.eu>

3 files changed, 123 insertions, 0 deletions

diff --git a/hw/intc/Kconfig b/hw/intc/Kconfig
index 186cb5d..f469408 100644
--- a/hw/intc/Kconfig
+++ b/hw/intc/Kconfig
@@ -70,3 +70,6 @@ config SIFIVE_PLIC
 
 config GOLDFISH_PIC
     bool
+
+config M68K_IRQC
+    bool
diff --git a/hw/intc/m68k_irqc.c b/hw/intc/m68k_irqc.c
new file mode 100644
index 0000000..2133d2a
--- /dev/null
+++ b/hw/intc/m68k_irqc.c
@@ -0,0 +1,119 @@
+/*
+ * SPDX-License-Identifer: GPL-2.0-or-later
+ *
+ * QEMU Motorola 680x0 IRQ Controller
+ *
+ * (c) 2020 Laurent Vivier <laurent@vivier.eu>
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "migration/vmstate.h"
+#include "monitor/monitor.h"
+#include "hw/nmi.h"
+#include "hw/intc/intc.h"
+#include "hw/intc/m68k_irqc.h"
+
+
+static bool m68k_irqc_get_statistics(InterruptStatsProvider *obj,
+                                     uint64_t **irq_counts, unsigned int *nb_irqs)
+{
+    M68KIRQCState *s = M68K_IRQC(obj);
+
+    *irq_counts = s->stats_irq_count;
+    *nb_irqs = ARRAY_SIZE(s->stats_irq_count);
+    return true;
+}
+
+static void m68k_irqc_print_info(InterruptStatsProvider *obj, Monitor *mon)
+{
+    M68KIRQCState *s = M68K_IRQC(obj);
+    monitor_printf(mon, "m68k-irqc: ipr=0x%x\n", s->ipr);
+}
+
+static void m68k_set_irq(void *opaque, int irq, int level)
+{
+    M68KIRQCState *s = opaque;
+    M68kCPU *cpu = M68K_CPU(first_cpu);
+    int i;
+
+    if (level) {
+        s->ipr |= 1 << irq;
+        s->stats_irq_count[irq]++;
+    } else {
+        s->ipr &= ~(1 << irq);
+    }
+
+    for (i = M68K_IRQC_LEVEL_7; i >= M68K_IRQC_LEVEL_1; i--) {
+        if ((s->ipr >> i) & 1) {
+            m68k_set_irq_level(cpu, i + 1, i + M68K_IRQC_AUTOVECTOR_BASE);
+            return;
+        }
+    }
+    m68k_set_irq_level(cpu, 0, 0);
+}
+
+static void m68k_irqc_reset(DeviceState *d)
+{
+    M68KIRQCState *s = M68K_IRQC(d);
+    int i;
+
+    s->ipr = 0;
+    for (i = 0; i < ARRAY_SIZE(s->stats_irq_count); i++) {
+        s->stats_irq_count[i] = 0;
+    }
+}
+
+static void m68k_irqc_instance_init(Object *obj)
+{
+    qdev_init_gpio_in(DEVICE(obj), m68k_set_irq, M68K_IRQC_LEVEL_NUM);
+}
+
+static void m68k_nmi(NMIState *n, int cpu_index, Error **errp)
+{
+    m68k_set_irq(n, M68K_IRQC_LEVEL_7, 1);
+}
+
+static const VMStateDescription vmstate_m68k_irqc = {
+    .name = "m68k-irqc",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(ipr, M68KIRQCState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void m68k_irqc_class_init(ObjectClass *oc, void *data)
+ {
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    NMIClass *nc = NMI_CLASS(oc);
+    InterruptStatsProviderClass *ic = INTERRUPT_STATS_PROVIDER_CLASS(oc);
+
+    nc->nmi_monitor_handler = m68k_nmi;
+    dc->reset = m68k_irqc_reset;
+    dc->vmsd = &vmstate_m68k_irqc;
+    ic->get_statistics = m68k_irqc_get_statistics;
+    ic->print_info = m68k_irqc_print_info;
+}
+
+static const TypeInfo m68k_irqc_type_info = {
+    .name = TYPE_M68K_IRQC,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(M68KIRQCState),
+    .instance_init = m68k_irqc_instance_init,
+    .class_init = m68k_irqc_class_init,
+    .interfaces = (InterfaceInfo[]) {
+         { TYPE_NMI },
+         { TYPE_INTERRUPT_STATS_PROVIDER },
+         { }
+    },
+};
+
+static void q800_irq_register_types(void)
+{
+    type_register_static(&m68k_irqc_type_info);
+}
+
+type_init(q800_irq_register_types);
diff --git a/hw/intc/meson.build b/hw/intc/meson.build
index 5fcb923..1c29903 100644
--- a/hw/intc/meson.build
+++ b/hw/intc/meson.build
@@ -58,3 +58,4 @@ specific_ss.add(when: 'CONFIG_XIVE', if_true: files('xive.c'))
 specific_ss.add(when: ['CONFIG_KVM', 'CONFIG_XIVE'],
 		if_true: files('spapr_xive_kvm.c'))
 specific_ss.add(when: 'CONFIG_GOLDFISH_PIC', if_true: files('goldfish_pic.c'))
+specific_ss.add(when: 'CONFIG_M68K_IRQC', if_true: files('m68k_irqc.c'))