hw/fsi: Introduce IBM's Local bus

This is a part of patchset where IBM's Flexible Service Interface is
introduced.

The LBUS is modelled to maintain mapped memory for the devices. The
memory is mapped after CFAM config, peek table and FSI slave registers.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
[ clg: - removed lbus_add_device() bc unused
       - removed lbus_create_device() bc used only once
       - removed "address" property
       - updated meson.build to build fsi dir
       - included an empty hw/fsi/trace-events ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>

hw/Kconfig

@@ -9,6 +9,7 @@ source core/Kconfig
 source cxl/Kconfig
 source display/Kconfig
 source dma/Kconfig
+source fsi/Kconfig
 source gpio/Kconfig
 source hyperv/Kconfig
 source i2c/Kconfig

hw/fsi/Kconfig

@@ -0,0 +1,2 @@
+config FSI
+    bool

hw/fsi/lbus.c

@@ -0,0 +1,43 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 IBM Corp.
+ *
+ * IBM Local bus where FSI slaves are connected
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/fsi/lbus.h"
+
+#include "hw/qdev-properties.h"
+
+#include "trace.h"
+
+static void fsi_lbus_init(Object *o)
+{
+    FSILBus *lbus = FSI_LBUS(o);
+
+    memory_region_init(&lbus->mr, OBJECT(lbus), TYPE_FSI_LBUS, 1 * MiB);
+}
+
+static const TypeInfo fsi_lbus_info = {
+    .name = TYPE_FSI_LBUS,
+    .parent = TYPE_BUS,
+    .instance_init = fsi_lbus_init,
+    .instance_size = sizeof(FSILBus),
+};
+
+static const TypeInfo fsi_lbus_device_type_info = {
+    .name = TYPE_FSI_LBUS_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(FSILBusDevice),
+    .abstract = true,
+};
+
+static void fsi_lbus_register_types(void)
+{
+    type_register_static(&fsi_lbus_info);
+    type_register_static(&fsi_lbus_device_type_info);
+}
+
+type_init(fsi_lbus_register_types);

hw/fsi/meson.build

@@ -0,0 +1 @@
+system_ss.add(when: 'CONFIG_FSI', if_true: files('lbus.c'))

hw/fsi/trace.h

@@ -0,0 +1 @@
+#include "trace/trace-hw_fsi.h"

hw/meson.build

@@ -44,6 +44,7 @@ subdir('virtio')
 subdir('watchdog')
 subdir('xen')
 subdir('xenpv')
+subdir('fsi')
 
 subdir('alpha')
 subdir('arm')

include/hw/fsi/lbus.h

@@ -0,0 +1,32 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 IBM Corp.
+ *
+ * IBM Local bus and connected device structures.
+ */
+#ifndef FSI_LBUS_H
+#define FSI_LBUS_H
+
+#include "hw/qdev-core.h"
+#include "qemu/units.h"
+#include "exec/memory.h"
+
+#define TYPE_FSI_LBUS_DEVICE "fsi.lbus.device"
+OBJECT_DECLARE_SIMPLE_TYPE(FSILBusDevice, FSI_LBUS_DEVICE)
+
+typedef struct FSILBusDevice {
+    DeviceState parent;
+
+    MemoryRegion iomem;
+} FSILBusDevice;
+
+#define TYPE_FSI_LBUS "fsi.lbus"
+OBJECT_DECLARE_SIMPLE_TYPE(FSILBus, FSI_LBUS)
+
+typedef struct FSILBus {
+    BusState bus;
+
+    MemoryRegion mr;
+} FSILBus;
+
+#endif /* FSI_LBUS_H */

meson.build

@@ -3289,6 +3289,7 @@ if have_system
     'hw/char',
     'hw/display',
     'hw/dma',
+    'hw/fsi',
     'hw/hyperv',
     'hw/i2c',
     'hw/i386',