f5095aa380
Create a new "unimplemented" sysbus device, which simply accepts all read and write accesses, and implements them as read-as-zero, write-ignored, with logging of the access as LOG_UNIMP. This is useful for stubbing out bits of an SoC or board model which haven't been written yet. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Message-id: 1484247815-15279-3-git-send-email-peter.maydell@linaro.org
108 lines
2.9 KiB
C
108 lines
2.9 KiB
C
/* "Unimplemented" device
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*
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* This is a dummy device which accepts and logs all accesses.
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* It's useful for stubbing out regions of an SoC or board
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* map which correspond to devices that have not yet been
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* implemented. This is often sufficient to placate initial
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* guest device driver probing such that the system will
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* come up.
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*
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* Copyright Linaro Limited, 2017
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* Written by Peter Maydell
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*/
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#include "qemu/osdep.h"
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#include "hw/hw.h"
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#include "hw/sysbus.h"
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#include "hw/misc/unimp.h"
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#include "qemu/log.h"
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#include "qapi/error.h"
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#define UNIMPLEMENTED_DEVICE(obj) \
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OBJECT_CHECK(UnimplementedDeviceState, (obj), TYPE_UNIMPLEMENTED_DEVICE)
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typedef struct {
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SysBusDevice parent_obj;
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MemoryRegion iomem;
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char *name;
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uint64_t size;
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} UnimplementedDeviceState;
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static uint64_t unimp_read(void *opaque, hwaddr offset, unsigned size)
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{
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UnimplementedDeviceState *s = UNIMPLEMENTED_DEVICE(opaque);
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qemu_log_mask(LOG_UNIMP, "%s: unimplemented device read "
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"(size %d, offset 0x%" HWADDR_PRIx ")\n",
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s->name, size, offset);
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return 0;
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}
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static void unimp_write(void *opaque, hwaddr offset,
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uint64_t value, unsigned size)
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{
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UnimplementedDeviceState *s = UNIMPLEMENTED_DEVICE(opaque);
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qemu_log_mask(LOG_UNIMP, "%s: unimplemented device write "
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"(size %d, value 0x%" PRIx64
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", offset 0x%" HWADDR_PRIx ")\n",
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s->name, size, value, offset);
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}
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static const MemoryRegionOps unimp_ops = {
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.read = unimp_read,
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.write = unimp_write,
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.impl.min_access_size = 1,
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.impl.max_access_size = 8,
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.valid.min_access_size = 1,
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.valid.max_access_size = 8,
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.endianness = DEVICE_NATIVE_ENDIAN,
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};
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static void unimp_realize(DeviceState *dev, Error **errp)
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{
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UnimplementedDeviceState *s = UNIMPLEMENTED_DEVICE(dev);
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if (s->size == 0) {
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error_setg(errp, "property 'size' not specified or zero");
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return;
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}
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if (s->name == NULL) {
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error_setg(errp, "property 'name' not specified");
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return;
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}
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memory_region_init_io(&s->iomem, OBJECT(s), &unimp_ops, s,
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s->name, s->size);
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sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
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}
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static Property unimp_properties[] = {
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DEFINE_PROP_UINT64("size", UnimplementedDeviceState, size, 0),
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DEFINE_PROP_STRING("name", UnimplementedDeviceState, name),
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DEFINE_PROP_END_OF_LIST(),
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};
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static void unimp_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(klass);
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dc->realize = unimp_realize;
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dc->props = unimp_properties;
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}
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static const TypeInfo unimp_info = {
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.name = TYPE_UNIMPLEMENTED_DEVICE,
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.parent = TYPE_SYS_BUS_DEVICE,
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.instance_size = sizeof(UnimplementedDeviceState),
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.class_init = unimp_class_init,
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};
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static void unimp_register_types(void)
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{
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type_register_static(&unimp_info);
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}
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type_init(unimp_register_types)
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