[PATCH v3 1/8] hw/fsi: Introduce IBM's Local bus

[Ninad Palsule]

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

The LBUS is modelled to maintain the qdev bus hierarchy and to take
advantage of the object model to automatically generate the CFAM
configuration block. The configuration block presents engines in the
order they are attached to the CFAM's LBUS. Engine implementations
should subclass the LBusDevice and set the 'config' member of
LBusDeviceClass to match the engine's type.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
---
v2:
- Incorporated Joel's review comments.
---
 hw/Kconfig            |  1 +
 hw/fsi/Kconfig        |  2 +
 hw/fsi/lbus.c         | 94 +++++++++++++++++++++++++++++++++++++++++++
 hw/fsi/meson.build    |  1 +
 hw/meson.build        |  1 +
 include/hw/fsi/lbus.h | 48 ++++++++++++++++++++++
 include/qemu/bitops.h |  6 +++
 7 files changed, 153 insertions(+)
 create mode 100644 hw/fsi/Kconfig
 create mode 100644 hw/fsi/lbus.c
 create mode 100644 hw/fsi/meson.build
 create mode 100644 include/hw/fsi/lbus.h

diff --git a/hw/Kconfig b/hw/Kconfig
index ba62ff6417..2ccb73add5 100644
--- a/hw/Kconfig
+++ b/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
diff --git a/hw/fsi/Kconfig b/hw/fsi/Kconfig
new file mode 100644
index 0000000000..687449e14e
--- /dev/null
+++ b/hw/fsi/Kconfig
@@ -0,0 +1,2 @@
+config LBUS
+    bool
diff --git a/hw/fsi/lbus.c b/hw/fsi/lbus.c
new file mode 100644
index 0000000000..afb26ef7ea
--- /dev/null
+++ b/hw/fsi/lbus.c
@@ -0,0 +1,94 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2023 IBM Corp.
+ *
+ * IBM Local bus where FSI slaves are connected
+ */
+
+#include "qemu/osdep.h"
+
+#include "qapi/error.h"
+#include "qemu/log.h"
+
+#include "hw/fsi/lbus.h"
+
+#include "hw/qdev-properties.h"
+
+static void lbus_realize(BusState *bus, Error **errp)
+{
+    LBusNode *node;
+    LBus *lbus = LBUS(bus);
+
+    memory_region_init(&lbus->mr, OBJECT(lbus), TYPE_LBUS,
+                       (2 * 1024 * 1024) - 0x400);
+
+    QLIST_FOREACH(node, &lbus->devices, next) {
+        memory_region_add_subregion(&lbus->mr, node->ldev->address,
+                                    &node->ldev->iomem);
+    }
+}
+
+static void lbus_init(Object *o)
+{
+}
+
+static void lbus_class_init(ObjectClass *klass, void *data)
+{
+    BusClass *k = BUS_CLASS(klass);
+    k->realize = lbus_realize;
+}
+
+static const TypeInfo lbus_info = {
+    .name = TYPE_LBUS,
+    .parent = TYPE_BUS,
+    .instance_init = lbus_init,
+    .instance_size = sizeof(LBus),
+    .class_init = lbus_class_init,
+};
+
+static Property lbus_device_props[] = {
+    DEFINE_PROP_UINT32("address", LBusDevice, address, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+DeviceState *lbus_create_device(LBus *bus, const char *type, uint32_t addr)
+{
+    DeviceState *dev;
+    LBusNode *node;
+
+    dev = qdev_new(type);
+    qdev_prop_set_uint8(dev, "address", addr);
+    qdev_realize_and_unref(dev, &bus->bus, &error_fatal);
+
+    /* Move to post_load */
+    node = g_malloc(sizeof(struct LBusNode));
+    node->ldev = LBUS_DEVICE(dev);
+    QLIST_INSERT_HEAD(&bus->devices, node, next);
+
+    return dev;
+}
+
+static void lbus_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->bus_type = TYPE_LBUS;
+    device_class_set_props(dc, lbus_device_props);
+}
+
+static const TypeInfo lbus_device_type_info = {
+    .name = TYPE_LBUS_DEVICE,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(LBusDevice),
+    .abstract = true,
+    .class_init = lbus_device_class_init,
+    .class_size = sizeof(LBusDeviceClass),
+};
+
+static void lbus_register_types(void)
+{
+    type_register_static(&lbus_info);
+    type_register_static(&lbus_device_type_info);
+}
+
+type_init(lbus_register_types);
diff --git a/hw/fsi/meson.build b/hw/fsi/meson.build
new file mode 100644
index 0000000000..e1007d5fea
--- /dev/null
+++ b/hw/fsi/meson.build
@@ -0,0 +1 @@
+system_ss.add(when: 'CONFIG_LBUS', if_true: files('lbus.c'))
diff --git a/hw/meson.build b/hw/meson.build
index c7ac7d3d75..6c71ee9cfa 100644
--- a/hw/meson.build
+++ b/hw/meson.build
@@ -43,6 +43,7 @@ subdir('virtio')
 subdir('watchdog')
 subdir('xen')
 subdir('xenpv')
+subdir('fsi')
 
 subdir('alpha')
 subdir('arm')
diff --git a/include/hw/fsi/lbus.h b/include/hw/fsi/lbus.h
new file mode 100644
index 0000000000..fafc065178
--- /dev/null
+++ b/include/hw/fsi/lbus.h
@@ -0,0 +1,48 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2023 IBM Corp.
+ *
+ * IBM Local bus and connected device structures.
+ */
+#ifndef FSI_LBUS_H
+#define FSI_LBUS_H
+
+#include "exec/memory.h"
+#include "hw/qdev-core.h"
+
+#define TYPE_LBUS_DEVICE "lbus.device"
+OBJECT_DECLARE_TYPE(LBusDevice, LBusDeviceClass, LBUS_DEVICE)
+
+typedef struct LBusDevice {
+    DeviceState parent;
+
+    MemoryRegion iomem;
+    uint32_t address;
+} LBusDevice;
+
+typedef struct LBusDeviceClass {
+    DeviceClass parent;
+
+    uint32_t config;
+} LBusDeviceClass;
+
+typedef struct LBusNode {
+    LBusDevice *ldev;
+
+    QLIST_ENTRY(LBusNode) next;
+} LBusNode;
+
+#define TYPE_LBUS "lbus"
+OBJECT_DECLARE_SIMPLE_TYPE(LBus, LBUS)
+
+typedef struct LBus {
+    BusState bus;
+
+    MemoryRegion mr;
+
+    QLIST_HEAD(, LBusNode) devices;
+} LBus;
+
+DeviceState *lbus_create_device(LBus *bus, const char *type, uint32_t addr);
+int lbus_add_device(LBus *bus, LBusDevice *dev);
+#endif /* FSI_LBUS_H */
diff --git a/include/qemu/bitops.h b/include/qemu/bitops.h
index cb3526d1f4..e12496f619 100644
--- a/include/qemu/bitops.h
+++ b/include/qemu/bitops.h
@@ -618,4 +618,10 @@ static inline uint64_t half_unshuffle64(uint64_t x)
     return x;
 }
 
+/* Bitwise operations at the word level. */
+#define BE_BIT(x)                          BIT(31 - (x))
+#define GENMASK(t, b) \
+    (((1ULL << ((t) + 1)) - 1) & ~((1ULL << (b)) - 1))
+#define BE_GENMASK(t, b)                   GENMASK(BE_BIT(t), BE_BIT(b))
+
 #endif
-- 
2.39.2