hw/misc/empty_slot: Move the 'hw/misc' and cover in MAINTAINERS

Add an entry for the 'empty_slot' device.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Acked-by: Artyom Tarasenko <atar4qemu@gmail.com>
Message-Id: <20200510152840.13558-7-f4bug@amsat.org>

3 files changed, 112 insertions, 0 deletions

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 60a9d80..5aaca8a 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -10,6 +10,7 @@ common-obj-$(CONFIG_EDU) += edu.o
 common-obj-$(CONFIG_PCA9552) += pca9552.o
 
 common-obj-$(CONFIG_UNIMP) += unimp.o
+common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o
 common-obj-$(CONFIG_FW_CFG_DMA) += vmcoreinfo.o
 
 # ARM devices
diff --git a/hw/misc/empty_slot.c b/hw/misc/empty_slot.c
new file mode 100644
index 0000000..54be085
--- /dev/null
+++ b/hw/misc/empty_slot.c
@@ -0,0 +1,107 @@
+/*
+ * QEMU Empty Slot
+ *
+ * The empty_slot device emulates known to a bus but not connected devices.
+ *
+ * Copyright (c) 2010 Artyom Tarasenko
+ *
+ * This code is licensed under the GNU GPL v2 or (at your option) any later
+ * version.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/qdev-properties.h"
+#include "hw/misc/empty_slot.h"
+#include "trace.h"
+
+#define TYPE_EMPTY_SLOT "empty_slot"
+#define EMPTY_SLOT(obj) OBJECT_CHECK(EmptySlot, (obj), TYPE_EMPTY_SLOT)
+
+typedef struct EmptySlot {
+    SysBusDevice parent_obj;
+
+    MemoryRegion iomem;
+    char *name;
+    uint64_t size;
+} EmptySlot;
+
+static uint64_t empty_slot_read(void *opaque, hwaddr addr,
+                                unsigned size)
+{
+    EmptySlot *s = EMPTY_SLOT(opaque);
+
+    trace_empty_slot_write(addr, size << 1, 0, size, s->name);
+
+    return 0;
+}
+
+static void empty_slot_write(void *opaque, hwaddr addr,
+                             uint64_t val, unsigned size)
+{
+    EmptySlot *s = EMPTY_SLOT(opaque);
+
+    trace_empty_slot_write(addr, size << 1, val, size, s->name);
+}
+
+static const MemoryRegionOps empty_slot_ops = {
+    .read = empty_slot_read,
+    .write = empty_slot_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+void empty_slot_init(hwaddr addr, uint64_t slot_size)
+{
+    if (slot_size > 0) {
+        /* Only empty slots larger than 0 byte need handling. */
+        DeviceState *dev;
+
+        dev = qdev_create(NULL, TYPE_EMPTY_SLOT);
+
+        qdev_prop_set_uint64(dev, "size", slot_size);
+        qdev_init_nofail(dev);
+
+        sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
+    }
+}
+
+static void empty_slot_realize(DeviceState *dev, Error **errp)
+{
+    EmptySlot *s = EMPTY_SLOT(dev);
+
+    if (s->name == NULL) {
+        s->name = g_strdup("empty-slot");
+    }
+    memory_region_init_io(&s->iomem, OBJECT(s), &empty_slot_ops, s,
+                          s->name, s->size);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+}
+
+static Property empty_slot_properties[] = {
+    DEFINE_PROP_UINT64("size", EmptySlot, size, 0),
+    DEFINE_PROP_STRING("name", EmptySlot, name),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void empty_slot_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = empty_slot_realize;
+    device_class_set_props(dc, empty_slot_properties);
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
+
+static const TypeInfo empty_slot_info = {
+    .name          = TYPE_EMPTY_SLOT,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(EmptySlot),
+    .class_init    = empty_slot_class_init,
+};
+
+static void empty_slot_register_types(void)
+{
+    type_register_static(&empty_slot_info);
+}
+
+type_init(empty_slot_register_types)
diff --git a/hw/misc/trace-events b/hw/misc/trace-events
index a5862b2..0cb4c64 100644
--- a/hw/misc/trace-events
+++ b/hw/misc/trace-events
@@ -39,6 +39,10 @@ ecc_mem_readl_ecr1(uint32_t ret) "Read event count 2 0x%08x"
 ecc_diag_mem_writeb(uint64_t addr, uint32_t val) "Write diagnostic %"PRId64" = 0x%02x"
 ecc_diag_mem_readb(uint64_t addr, uint32_t ret) "Read diagnostic %"PRId64"= 0x%02x"
 
+# empty_slot.c
+empty_slot_read(uint64_t addr, unsigned width, uint64_t value, unsigned size, const char *name) "rd addr:0x%04"PRIx64" data:0x%0*"PRIx64" size %u [%s]"
+empty_slot_write(uint64_t addr, unsigned width, uint64_t value, unsigned size, const char *name) "wr addr:0x%04"PRIx64" data:0x%0*"PRIx64" size %u [%s]"
+
 # slavio_misc.c
 slavio_misc_update_irq_raise(void) "Raise IRQ"
 slavio_misc_update_irq_lower(void) "Lower IRQ"