acpi: q35: isa bridge: use AcpiDevAmlIf interface to build ISA device descriptors

replaces adhoc build_isa_devices_aml() with generic AcpiDevAmlIf
way to build bridge AML including all devices that are attached
to its ISA bus.

Later when PCI is converted to AcpiDevAmlIf, build_q35_isa_bridge()
will also be dropped since PCI parts itself will take care of
building device prologue/epilogue AML for each enumerated PCI device.

Expected AML change is contextual, where ISA devices are moved from
separately declared _SB.PCI0.ISA scope, directly under Device(ISA)
node.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20220608135340.3304695-21-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/acpi-build.c

@@ -864,20 +864,6 @@ static Aml *build_vmbus_device_aml(VMBusBridge *vmbus_bridge)
     return dev;
 }
 
-static void build_isa_devices_aml(Aml *table)
-{
-    bool ambiguous;
-    Object *obj = object_resolve_path_type("", TYPE_ISA_BUS, &ambiguous);
-    Aml *scope;
-
-    assert(obj && !ambiguous);
-
-    scope = aml_scope("_SB.PCI0.ISA");
-    isa_build_aml(ISA_BUS(obj), scope);
-
-    aml_append(table, scope);
-}
-
 static void build_dbg_aml(Aml *table)
 {
     Aml *field;
@@ -1263,15 +1249,22 @@ static void build_q35_isa_bridge(Aml *table)
 {
     Aml *dev;
     Aml *scope;
+    Object *obj;
+    bool ambiguous;
+
+    /*
+     * temporarily fish out isa bridge, build_q35_isa_bridge() will be dropped
+     * once PCI is converted to AcpiDevAmlIf and would be ble to generate
+     * AML for bridge itself
+     */
+    obj = object_resolve_path_type("", TYPE_ICH9_LPC_DEVICE, &ambiguous);
+    assert(obj && !ambiguous);
 
     scope =  aml_scope("_SB.PCI0");
     dev = aml_device("ISA");
     aml_append(dev, aml_name_decl("_ADR", aml_int(0x001F0000)));
 
-    /* ICH9 PCI to ISA irq remapping */
+    call_dev_aml_func(DEVICE(obj), dev);
-    aml_append(dev, aml_operation_region("PIRQ", AML_PCI_CONFIG,
-                                         aml_int(0x60), 0x0C));
-
     aml_append(scope, dev);
     aml_append(table, scope);
 }
@@ -1531,7 +1524,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
             build_hpet_aml(dsdt);
         }
         build_q35_isa_bridge(dsdt);
-        build_isa_devices_aml(dsdt);
         if (pm->pcihp_bridge_en) {
             build_x86_acpi_pci_hotplug(dsdt, pm->pcihp_io_base);
         }

hw/isa/lpc_ich9.c

@@ -50,6 +50,7 @@
 #include "hw/core/cpu.h"
 #include "hw/nvram/fw_cfg.h"
 #include "qemu/cutils.h"
+#include "hw/acpi/acpi_aml_interface.h"
 
 /*****************************************************************************/
 /* ICH9 LPC PCI to ISA bridge */
@@ -803,12 +804,28 @@ static void ich9_send_gpe(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
     acpi_send_gpe_event(&s->pm.acpi_regs, s->pm.irq, ev);
 }
 
+static void build_ich9_isa_aml(AcpiDevAmlIf *adev, Aml *scope)
+{
+    BusChild *kid;
+    ICH9LPCState *s = ICH9_LPC_DEVICE(adev);
+    BusState *bus = BUS(s->isa_bus);
+
+    /* ICH9 PCI to ISA irq remapping */
+    aml_append(scope, aml_operation_region("PIRQ", AML_PCI_CONFIG,
+                                           aml_int(0x60), 0x0C));
+
+    QTAILQ_FOREACH(kid, &bus->children, sibling) {
+            call_dev_aml_func(DEVICE(kid->child), scope);
+    }
+}
+
 static void ich9_lpc_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(klass);
     AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_CLASS(klass);
+    AcpiDevAmlIfClass *amldevc = ACPI_DEV_AML_IF_CLASS(klass);
 
     set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
     dc->reset = ich9_lpc_reset;
@@ -833,6 +850,7 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
     adevc->ospm_status = ich9_pm_ospm_status;
     adevc->send_event = ich9_send_gpe;
     adevc->madt_cpu = pc_madt_cpu_entry;
+    amldevc->build_dev_aml = build_ich9_isa_aml;
 }
 
 static const TypeInfo ich9_lpc_info = {
@@ -845,6 +863,7 @@ static const TypeInfo ich9_lpc_info = {
         { TYPE_HOTPLUG_HANDLER },
         { TYPE_ACPI_DEVICE_IF },
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { TYPE_ACPI_DEV_AML_IF },
         { }
     }
 };