hw/intc/loongarch_extioi: Add extioi virt extension definition

On LoongArch, IRQs can be routed to four vcpus with hardware extended
IRQ model. This patch adds the virt extension definition so that
the IRQ can route to 256 vcpus.

    1.Extended IRQ model:
                                    |
    +-----------+     +-------------|--------+     +-----------+
    | IPI/Timer | --> | CPUINTC(0-3)|(4-255) | <-- | IPI/Timer |
    +-----------+     +-------------|--------+     +-----------+
                            ^       |
                            |
                       +---------+
                       | EIOINTC |
                       +---------+
                        ^       ^
                        |       |
                 +---------+ +---------+
                 | PCH-PIC | | PCH-MSI |
                 +---------+ +---------+
                   ^      ^          ^
                   |      |          |
            +--------+ +---------+ +---------+
            | UARTs  | | Devices | | Devices |
            +--------+ +---------+ +---------+

    2.Virt extended IRQ model:

      +-----+    +---------------+     +-------+
      | IPI |--> | CPUINTC(0-255)| <-- | Timer |
      +-----+    +---------------+     +-------+
                        ^
                        |
                  +-----------+
                  | V-EIOINTC |
                  +-----------+
                   ^         ^
                   |         |
            +---------+ +---------+
            | PCH-PIC | | PCH-MSI |
            +---------+ +---------+
              ^      ^          ^
              |      |          |
       +--------+ +---------+ +---------+
       | UARTs  | | Devices | | Devices |
       +--------+ +---------+ +---------+

Signed-off-by: Song Gao <gaosong@loongson.cn>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-Id: <20240528083855.1912757-2-gaosong@loongson.cn>

1 files changed, 84 insertions, 4 deletions

diff --git a/hw/intc/loongarch_extioi.c b/hw/intc/loongarch_extioi.c
index 0b35854..1e8e011 100644
--- a/hw/intc/loongarch_extioi.c
+++ b/hw/intc/loongarch_extioi.c
@@ -143,10 +143,13 @@ static inline void extioi_update_sw_coremap(LoongArchExtIOI *s, int irq,
 
     for (i = 0; i < 4; i++) {
         cpu = val & 0xff;
-        cpu = ctz32(cpu);
-        cpu = (cpu >= 4) ? 0 : cpu;
         val = val >> 8;
 
+        if (!(s->status & BIT(EXTIOI_ENABLE_CPU_ENCODE))) {
+            cpu = ctz32(cpu);
+            cpu = (cpu >= 4) ? 0 : cpu;
+        }
+
         if (s->sw_coremap[irq + i] == cpu) {
             continue;
         }
@@ -265,6 +268,61 @@ static const MemoryRegionOps extioi_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+static MemTxResult extioi_virt_readw(void *opaque, hwaddr addr, uint64_t *data,
+                                     unsigned size, MemTxAttrs attrs)
+{
+    LoongArchExtIOI *s = LOONGARCH_EXTIOI(opaque);
+
+    switch (addr) {
+    case EXTIOI_VIRT_FEATURES:
+        *data = s->features;
+        break;
+    case EXTIOI_VIRT_CONFIG:
+        *data = s->status;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    return MEMTX_OK;
+}
+
+static MemTxResult extioi_virt_writew(void *opaque, hwaddr addr,
+                          uint64_t val, unsigned size,
+                          MemTxAttrs attrs)
+{
+    LoongArchExtIOI *s = LOONGARCH_EXTIOI(opaque);
+
+    switch (addr) {
+    case EXTIOI_VIRT_FEATURES:
+        return MEMTX_ACCESS_ERROR;
+
+    case EXTIOI_VIRT_CONFIG:
+        /*
+         * extioi features can only be set at disabled status
+         */
+        if ((s->status & BIT(EXTIOI_ENABLE)) && val) {
+            return MEMTX_ACCESS_ERROR;
+        }
+
+        s->status = val & s->features;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+    return MEMTX_OK;
+}
+
+static const MemoryRegionOps extioi_virt_ops = {
+    .read_with_attrs = extioi_virt_readw,
+    .write_with_attrs = extioi_virt_writew,
+    .impl.min_access_size = 4,
+    .impl.max_access_size = 4,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 8,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static void loongarch_extioi_realize(DeviceState *dev, Error **errp)
 {
     LoongArchExtIOI *s = LOONGARCH_EXTIOI(dev);
@@ -284,6 +342,16 @@ static void loongarch_extioi_realize(DeviceState *dev, Error **errp)
     memory_region_init_io(&s->extioi_system_mem, OBJECT(s), &extioi_ops,
                           s, "extioi_system_mem", 0x900);
     sysbus_init_mmio(sbd, &s->extioi_system_mem);
+
+    if (s->features & BIT(EXTIOI_HAS_VIRT_EXTENSION)) {
+        memory_region_init_io(&s->virt_extend, OBJECT(s), &extioi_virt_ops,
+                              s, "extioi_virt", EXTIOI_VIRT_SIZE);
+        sysbus_init_mmio(sbd, &s->virt_extend);
+        s->features |= EXTIOI_VIRT_HAS_FEATURES;
+    } else {
+        s->status |= BIT(EXTIOI_ENABLE);
+    }
+
     s->cpu = g_new0(ExtIOICore, s->num_cpu);
     if (s->cpu == NULL) {
         error_setg(errp, "Memory allocation for ExtIOICore faile");
@@ -304,6 +372,13 @@ static void loongarch_extioi_finalize(Object *obj)
     g_free(s->cpu);
 }
 
+static void loongarch_extioi_reset(DeviceState *d)
+{
+    LoongArchExtIOI *s = LOONGARCH_EXTIOI(d);
+
+    s->status = 0;
+}
+
 static int vmstate_extioi_post_load(void *opaque, int version_id)
 {
     LoongArchExtIOI *s = LOONGARCH_EXTIOI(opaque);
@@ -333,8 +408,8 @@ static const VMStateDescription vmstate_extioi_core = {
 
 static const VMStateDescription vmstate_loongarch_extioi = {
     .name = TYPE_LOONGARCH_EXTIOI,
-    .version_id = 2,
-    .minimum_version_id = 2,
+    .version_id = 3,
+    .minimum_version_id = 3,
     .post_load = vmstate_extioi_post_load,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT32_ARRAY(bounce, LoongArchExtIOI, EXTIOI_IRQS_GROUP_COUNT),
@@ -347,12 +422,16 @@ static const VMStateDescription vmstate_loongarch_extioi = {
 
         VMSTATE_STRUCT_VARRAY_POINTER_UINT32(cpu, LoongArchExtIOI, num_cpu,
                          vmstate_extioi_core, ExtIOICore),
+        VMSTATE_UINT32(features, LoongArchExtIOI),
+        VMSTATE_UINT32(status, LoongArchExtIOI),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static Property extioi_properties[] = {
     DEFINE_PROP_UINT32("num-cpu", LoongArchExtIOI, num_cpu, 1),
+    DEFINE_PROP_BIT("has-virtualization-extension", LoongArchExtIOI, features,
+                    EXTIOI_HAS_VIRT_EXTENSION, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -361,6 +440,7 @@ static void loongarch_extioi_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->realize = loongarch_extioi_realize;
+    dc->reset   = loongarch_extioi_reset;
     device_class_set_props(dc, extioi_properties);
     dc->vmsd = &vmstate_loongarch_extioi;
 }