[Qemu-devel] [PATCH 10/18] armv7m: NVIC initialization

[Michael Davidsaver <mdavidsaver@gmail.com>]

Signed-off-by: Michael Davidsaver <mdavidsaver@gmail.com>
---
 hw/intc/armv7m_nvic.c | 107 ++++++++++++++++++++++++--------------------------
 1 file changed, 51 insertions(+), 56 deletions(-)

diff --git a/hw/intc/armv7m_nvic.c b/hw/intc/armv7m_nvic.c
index c860b36..8eaf677 100644
--- a/hw/intc/armv7m_nvic.c
+++ b/hw/intc/armv7m_nvic.c
@@ -827,7 +827,7 @@ int nvic_post_load(void *opaque, int version_id)
         set_prio(s, i, s->vectors[i].raw_prio);
     }
 
-    nvic_irq_update(s, highest_runnable_prio(s->cpu));
+    nvic_irq_update(s, 0);
 
     return 0;
 }
@@ -883,66 +883,66 @@ static const VMStateDescription vmstate_nvic = {
     }
 };
 
+static Property props_nvic[] = {
+    DEFINE_PROP_UINT32("num-irq", nvic_state, num_irq, 64),
+    DEFINE_PROP_END_OF_LIST()
+};
+
 static void armv7m_nvic_reset(DeviceState *dev)
 {
     nvic_state *s = NVIC(dev);
-    NVICClass *nc = NVIC_GET_CLASS(s);
-    nc->parent_reset(dev);
-    /* Common GIC reset resets to disabled; the NVIC doesn't have
-     * per-CPU interfaces so mark our non-existent CPU interface
-     * as enabled by default, and with a priority mask which allows
-     * all interrupts through.
-     */
-    s->gic.cpu_ctlr[0] = GICC_CTLR_EN_GRP0;
-    s->gic.priority_mask[0] = 0x100;
-    /* The NVIC as a whole is always enabled. */
-    s->gic.ctlr = 1;
+
+    s->vectors[ARMV7M_EXCP_RESET].enabled = 1;
+    s->vectors[ARMV7M_EXCP_NMI].enabled = 1;
+    s->vectors[ARMV7M_EXCP_HARD].enabled = 1;
+    s->vectors[ARMV7M_EXCP_SVC].enabled = 1;
+    s->vectors[ARMV7M_EXCP_DEBUG].enabled = 1;
+    s->vectors[ARMV7M_EXCP_PENDSV].enabled = 1;
+
+    s->vectors[ARMV7M_EXCP_RESET].prio_group = -3;
+    s->vectors[ARMV7M_EXCP_NMI].prio_group = -2;
+    s->vectors[ARMV7M_EXCP_HARD].prio_group = -1;
+
     systick_reset(s);
 }
 
 static void armv7m_nvic_realize(DeviceState *dev, Error **errp)
 {
     nvic_state *s = NVIC(dev);
-    NVICClass *nc = NVIC_GET_CLASS(s);
-    Error *local_err = NULL;
-
-    /* The NVIC always has only one CPU */
-    s->gic.num_cpu = 1;
-    /* Tell the common code we're an NVIC */
-    s->gic.revision = 0xffffffff;
-    s->num_irq = s->gic.num_irq;
-    nc->parent_realize(dev, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+
+    /* evil hack to get ARMCPU* ahead of time */
+    assert(cpus.tqh_first);
+    assert(!CPU_NEXT(cpus.tqh_first));
+    s->cpu = ARM_CPU(cpus.tqh_first);
+    assert(s->cpu);
+
+    if (s->num_irq > NVIC_MAX_IRQ) {
+        error_setg(errp, TYPE_NVIC " num_irq too large");
         return;
     }
-    gic_init_irqs_and_distributor(&s->gic);
-    /* The NVIC and system controller register area looks like this:
-     *  0..0xff : system control registers, including systick
-     *  0x100..0xcff : GIC-like registers
-     *  0xd00..0xfff : system control registers
-     * We use overlaying to put the GIC like registers
-     * over the top of the system control register region.
-     */
-    memory_region_init(&s->container, OBJECT(s), "nvic", 0x1000);
-    /* The system register region goes at the bottom of the priority
-     * stack as it covers the whole page.
+
+    qdev_init_gpio_in(dev, set_irq_level, s->num_irq);
+
+    s->num_irq += 16; /* include space for internal exception vectors */
+
+    /* The NVIC and system controller register area starts at 0xe000e000
+     * and looks like this:
+     *  0x004 - ICTR
+     *  0x010 - 0x1c - systick
+     *  0x100..0x7ec - NVIC
+     *  0x7f0..0xcff - Reserved
+     *  0xd00..0xd3c - SCS registers
+     *  0xd40..0xeff - Reserved or Not implemented
+     *  0xf00 - STIR
      */
-    memory_region_init_io(&s->sysregmem, OBJECT(s), &nvic_sysreg_ops, s,
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &nvic_sysreg_ops, s,
                           "nvic_sysregs", 0x1000);
-    memory_region_add_subregion(&s->container, 0, &s->sysregmem);
-    /* Alias the GIC region so we can get only the section of it
-     * we need, and layer it on top of the system register region.
-     */
-    memory_region_init_alias(&s->gic_iomem_alias, OBJECT(s),
-                             "nvic-gic", &s->gic.iomem,
-                             0x100, 0xc00);
-    memory_region_add_subregion_overlap(&s->container, 0x100,
-                                        &s->gic_iomem_alias, 1);
+
     /* Map the whole thing into system memory at the location required
      * by the v7M architecture.
      */
-    memory_region_add_subregion(get_system_memory(), 0xe000e000, &s->container);
+    memory_region_add_subregion(get_system_memory(), 0xe000e000, &s->iomem);
     s->systick.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, systick_timer_tick, s);
 }
 
@@ -954,36 +954,31 @@ static void armv7m_nvic_instance_init(Object *obj)
      * any user-specified property setting, so just modify the
      * value in the GICState struct.
      */
-    GICState *s = ARM_GIC_COMMON(obj);
     DeviceState *dev = DEVICE(obj);
     nvic_state *nvic = NVIC(obj);
-    /* The ARM v7m may have anything from 0 to 496 external interrupt
-     * IRQ lines. We default to 64. Other boards may differ and should
-     * set the num-irq property appropriately.
-     */
-    s->num_irq = 64;
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+
+    sysbus_init_irq(sbd, &nvic->excpout);
     qdev_init_gpio_out_named(dev, &nvic->sysresetreq, "SYSRESETREQ", 1);
 }
 
 static void armv7m_nvic_class_init(ObjectClass *klass, void *data)
 {
-    NVICClass *nc = NVIC_CLASS(klass);
     DeviceClass *dc = DEVICE_CLASS(klass);
 
-    nc->parent_reset = dc->reset;
-    nc->parent_realize = dc->realize;
     dc->vmsd  = &vmstate_nvic;
+    dc->props = props_nvic;
     dc->reset = armv7m_nvic_reset;
     dc->realize = armv7m_nvic_realize;
 }
 
 static const TypeInfo armv7m_nvic_info = {
     .name          = TYPE_NVIC,
-    .parent        = TYPE_ARM_GIC_COMMON,
+    .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_init = armv7m_nvic_instance_init,
     .instance_size = sizeof(nvic_state),
     .class_init    = armv7m_nvic_class_init,
-    .class_size    = sizeof(NVICClass),
+    .class_size    = sizeof(SysBusDeviceClass),
 };
 
 static void armv7m_nvic_register_types(void)
-- 
2.1.4