pcihp: make bridge describe itself using AcpiDevAmlIfClass:build_dev_aml

simplify build_append_pci_bus_devices() a bit by handling bridge
specific logic in bridge dedicated AcpiDevAmlIfClass::build_dev_aml
callback.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20230112140312.3096331-30-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/acpi/Kconfig

@@ -39,6 +39,10 @@ config ACPI_PCIHP
     bool
     depends on ACPI
 
+config ACPI_PCI_BRIDGE
+    bool
+    depends on ACPI && PCI && ACPI_PCIHP
+
 config ACPI_HMAT
     bool
     depends on ACPI

hw/acpi/meson.build

@@ -19,6 +19,7 @@ acpi_ss.add(when: 'CONFIG_ACPI_HW_REDUCED', if_true: files('generic_event_device
 acpi_ss.add(when: 'CONFIG_ACPI_HMAT', if_true: files('hmat.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_APEI', if_true: files('ghes.c'), if_false: files('ghes-stub.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_PIIX4', if_true: files('piix4.c'))
+acpi_ss.add(when: 'CONFIG_ACPI_PCI_BRIDGE', if_true: files('pci-bridge.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_PCIHP', if_true: files('pcihp.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_PCIHP', if_false: files('acpi-pci-hotplug-stub.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_VIOT', if_true: files('viot.c'))
@@ -30,9 +31,10 @@ if have_tpm
   acpi_ss.add(files('tpm.c'))
 endif
 softmmu_ss.add(when: 'CONFIG_ACPI', if_false: files('acpi-stub.c', 'aml-build-stub.c', 'ghes-stub.c', 'acpi_interface.c'))
+softmmu_ss.add(when: 'CONFIG_ACPI_PCI_BRIDGE', if_false: files('pci-bridge-stub.c'))
 softmmu_ss.add_all(when: 'CONFIG_ACPI', if_true: acpi_ss)
 softmmu_ss.add(when: 'CONFIG_ALL', if_true: files('acpi-stub.c', 'aml-build-stub.c',
                                                   'acpi-x86-stub.c', 'ipmi-stub.c', 'ghes-stub.c',
                                                   'acpi-mem-hotplug-stub.c', 'acpi-cpu-hotplug-stub.c',
                                                   'acpi-pci-hotplug-stub.c', 'acpi-nvdimm-stub.c',
-                                                  'cxl-stub.c'))
+                                                  'cxl-stub.c', 'pci-bridge-stub.c'))

hw/acpi/pci-bridge-stub.c

@@ -0,0 +1,20 @@
+/*
+ * QEMU ACPI PCI bridge stub
+ *
+ * Copyright (c) 2023 Red Hat, Inc.
+ *
+ * Author:
+ *   Igor Mammedov <imammedo@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/acpi/pci.h"
+
+void build_pci_bridge_aml(AcpiDevAmlIf *adev, Aml *scope)
+{
+}

hw/acpi/pci-bridge.c

@@ -0,0 +1,27 @@
+/*
+ * QEMU ACPI PCI bridge
+ *
+ * Copyright (c) 2023 Red Hat, Inc.
+ *
+ * Author:
+ *   Igor Mammedov <imammedo@redhat.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/acpi/pci.h"
+#include "hw/pci/pci_bridge.h"
+#include "hw/acpi/pcihp.h"
+
+void build_pci_bridge_aml(AcpiDevAmlIf *adev, Aml *scope)
+{
+    PCIBridge *br = PCI_BRIDGE(adev);
+
+    if (object_property_find(OBJECT(&br->sec_bus), ACPI_PCIHP_PROP_BSEL)) {
+        build_append_pci_bus_devices(scope, pci_bridge_get_sec_bus(br));
+    }
+}

hw/i386/Kconfig

@@ -58,6 +58,7 @@ config PC_ACPI
     select ACPI_X86
     select ACPI_CPU_HOTPLUG
     select ACPI_MEMORY_HOTPLUG
+    select ACPI_PCI_BRIDGE
     select ACPI_VIOT
     select SMBUS_EEPROM
     select PFLASH_CFI01

hw/i386/acpi-build.c

@@ -383,8 +383,7 @@ static void build_append_pcihp_notify_entry(Aml *method, int slot)
     aml_append(method, if_ctx);
 }
 
-static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
-                                         bool pcihp_bridge_en)
+void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus)
 {
     Aml *dev, *notify_method = NULL, *method;
     QObject *bsel;
@@ -406,7 +405,6 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
         /* ACPI spec: 1.0b: Table 6-2 _ADR Object Bus Types, PCI type */
         int adr = slot << 16 | func;
         bool hotpluggbale_slot = false;
-        bool bridge_in_acpi = false;
         bool cold_plugged_bridge = false;
 
         if (pdev) {
@@ -418,7 +416,6 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
              */
             cold_plugged_bridge = IS_PCI_BRIDGE(pdev) &&
                                   !DEVICE(pdev)->hotplugged;
-            bridge_in_acpi =  cold_plugged_bridge && pcihp_bridge_en;
 
             hotpluggbale_slot = bsel && dc->hotpluggable &&
                                 !cold_plugged_bridge;
@@ -471,16 +468,6 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus,
 
         call_dev_aml_func(DEVICE(pdev), dev);
 
-        if (bridge_in_acpi) {
-            /*
-             * device is coldplugged bridge,
-             * add child device descriptions into its scope
-             */
-            PCIBus *sec_bus = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
-
-            build_append_pci_bus_devices(dev, sec_bus, pcihp_bridge_en);
-        }
-
         if (hotpluggbale_slot) {
             aml_append(dev, aml_name_decl("_SUN", aml_int(slot)));
             /* add _EJ0 to make slot hotpluggable  */
@@ -1704,7 +1691,7 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
             PCIBus *bus = PCI_HOST_BRIDGE(pci_host)->bus;
             Aml *scope = aml_scope("PCI0");
             /* Scan all PCI buses. Generate tables to support hotplug. */
-            build_append_pci_bus_devices(scope, bus, pm->pcihp_bridge_en);
+            build_append_pci_bus_devices(scope, bus);
             aml_append(sb_scope, scope);
         }
     }

hw/pci/pci_bridge.c

@@ -37,6 +37,7 @@
 #include "qemu/range.h"
 #include "qapi/error.h"
 #include "hw/acpi/acpi_aml_interface.h"
+#include "hw/acpi/pci.h"
 
 /* PCI bridge subsystem vendor ID helper functions */
 #define PCI_SSVID_SIZEOF        8
@@ -468,10 +469,18 @@ int pci_bridge_qemu_reserve_cap_init(PCIDevice *dev, int cap_offset,
     return 0;
 }
 
+static void pci_bridge_class_init(ObjectClass *klass, void *data)
+{
+    AcpiDevAmlIfClass *adevc = ACPI_DEV_AML_IF_CLASS(klass);
+
+    adevc->build_dev_aml = build_pci_bridge_aml;
+}
+
 static const TypeInfo pci_bridge_type_info = {
     .name = TYPE_PCI_BRIDGE,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PCIBridge),
+    .class_init = pci_bridge_class_init,
     .abstract = true,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_ACPI_DEV_AML_IF },

include/hw/acpi/pci.h

@@ -27,6 +27,7 @@
 #define HW_ACPI_PCI_H
 
 #include "hw/acpi/bios-linker-loader.h"
+#include "hw/acpi/acpi_aml_interface.h"
 
 typedef struct AcpiMcfgInfo {
     uint64_t base;
@@ -36,4 +37,7 @@ typedef struct AcpiMcfgInfo {
 void build_mcfg(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info,
                 const char *oem_id, const char *oem_table_id);
 Aml *aml_pci_device_dsm(void);
+
+void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus);
+void build_pci_bridge_aml(AcpiDevAmlIf *adev, Aml *scope);
 #endif