TPM needs to know its own base address in order to generate its DSDT
device entry.

Signed-off-by: Joelle van Dyne <j@getutm.app>
---
 include/sysemu/tpm.h |  4 ++++
 hw/tpm/tpm-sysbus.c  | 47 ++++++++++++++++++++++++++++++++++++++++++++
 hw/tpm/meson.build   |  1 +
 3 files changed, 52 insertions(+)
 create mode 100644 hw/tpm/tpm-sysbus.c

diff --git a/include/sysemu/tpm.h b/include/sysemu/tpm.h
index 1ee568b3b6..ffd300e607 100644
--- a/include/sysemu/tpm.h
+++ b/include/sysemu/tpm.h
@@ -12,6 +12,8 @@
 #ifndef QEMU_TPM_H
 #define QEMU_TPM_H
 
+#include "qemu/osdep.h"
+#include "exec/hwaddr.h"
 #include "qapi/qapi-types-tpm.h"
 #include "qom/object.h"
 
@@ -78,6 +80,8 @@ static inline TPMVersion tpm_get_version(TPMIf *ti)
     return TPM_IF_GET_CLASS(ti)->get_version(ti);
 }
 
+void tpm_sysbus_plug(TPMIf *tpmif, Object *pbus, hwaddr pbus_base);
+
 #else /* CONFIG_TPM */
 
 #define tpm_init()  (0)
diff --git a/hw/tpm/tpm-sysbus.c b/hw/tpm/tpm-sysbus.c
new file mode 100644
index 0000000000..732ce34c73
--- /dev/null
+++ b/hw/tpm/tpm-sysbus.c
@@ -0,0 +1,47 @@
+/*
+ * tpm-sysbus.c - Support functions for SysBus TPM devices
+ *
+ * Copyright (c) 2023 QEMU contributors
+ *
+ * Authors:
+ *   Joelle van Dyne <j@getutm.app>
+ *
+ * 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 "sysemu/tpm.h"
+#include "hw/platform-bus.h"
+#include "hw/sysbus.h"
+#include "qapi/error.h"
+
+/**
+ * Called from a machine's pre_plug handler to set the device's physical addr.
+ */
+void tpm_sysbus_plug(TPMIf *tpmif, Object *pbus, hwaddr pbus_base)
+{
+    PlatformBusDevice *pbusdev = PLATFORM_BUS_DEVICE(pbus);
+    SysBusDevice *sbdev = SYS_BUS_DEVICE(tpmif);
+    MemoryRegion *sbdev_mr;
+    hwaddr tpm_base;
+    uint64_t tpm_size;
+
+    /* exit early if TPM is not a sysbus device */
+    if (!object_dynamic_cast(OBJECT(tpmif), TYPE_SYS_BUS_DEVICE)) {
+        return;
+    }
+
+    assert(object_dynamic_cast(pbus, TYPE_PLATFORM_BUS_DEVICE));
+
+    tpm_base = platform_bus_get_mmio_addr(pbusdev, sbdev, 0);
+    assert(tpm_base != -1);
+
+    tpm_base += pbus_base;
+
+    sbdev_mr = sysbus_mmio_get_region(sbdev, 0);
+    tpm_size = memory_region_size(sbdev_mr);
+
+    object_property_set_uint(OBJECT(sbdev), "x-baseaddr",
+                             tpm_base, &error_abort);
+    object_property_set_uint(OBJECT(sbdev), "x-size",
+                             tpm_size, &error_abort);
+}
diff --git a/hw/tpm/meson.build b/hw/tpm/meson.build
index cb8204d5bc..3060ac05e8 100644
--- a/hw/tpm/meson.build
+++ b/hw/tpm/meson.build
@@ -1,6 +1,7 @@
 system_ss.add(when: 'CONFIG_TPM_TIS', if_true: files('tpm_tis_common.c'))
 system_ss.add(when: 'CONFIG_TPM_TIS_ISA', if_true: files('tpm_tis_isa.c'))
 system_ss.add(when: 'CONFIG_TPM_TIS_SYSBUS', if_true: files('tpm_tis_sysbus.c'))
+system_ss.add(when: 'CONFIG_TPM_TIS_SYSBUS', if_true: files('tpm-sysbus.c'))
 system_ss.add(when: 'CONFIG_TPM_TIS_I2C', if_true: files('tpm_tis_i2c.c'))
 system_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_crb.c'))
 system_ss.add(when: 'CONFIG_TPM_CRB', if_true: files('tpm_crb_common.c'))
-- 
2.41.0