Instead of calling `memory_region_add_subregion` directly, we defer to
the caller to do it. This allows us to re-use the code for a SysBus
device.

Signed-off-by: Joelle van Dyne <j@getutm.app>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
 hw/tpm/tpm_ppi.h        | 10 +++-------
 hw/tpm/tpm_crb.c        |  4 ++--
 hw/tpm/tpm_crb_common.c |  3 +++
 hw/tpm/tpm_ppi.c        |  5 +----
 hw/tpm/tpm_tis_isa.c    |  5 +++--
 5 files changed, 12 insertions(+), 15 deletions(-)

diff --git a/hw/tpm/tpm_ppi.h b/hw/tpm/tpm_ppi.h
index bf5d4a300f..30863c6438 100644
--- a/hw/tpm/tpm_ppi.h
+++ b/hw/tpm/tpm_ppi.h
@@ -20,17 +20,13 @@ typedef struct TPMPPI {
 } TPMPPI;
 
 /**
- * tpm_ppi_init:
+ * tpm_ppi_init_memory:
  * @tpmppi: a TPMPPI
- * @m: the address-space / MemoryRegion to use
- * @addr: the address of the PPI region
  * @obj: the owner object
  *
- * Register the TPM PPI memory region at @addr on the given address
- * space for the object @obj.
+ * Creates the TPM PPI memory region.
  **/
-void tpm_ppi_init(TPMPPI *tpmppi, MemoryRegion *m,
-                  hwaddr addr, Object *obj);
+void tpm_ppi_init_memory(TPMPPI *tpmppi, Object *obj);
 
 /**
  * tpm_ppi_reset:
diff --git a/hw/tpm/tpm_crb.c b/hw/tpm/tpm_crb.c
index 3ef4977fb5..598c3e0161 100644
--- a/hw/tpm/tpm_crb.c
+++ b/hw/tpm/tpm_crb.c
@@ -107,8 +107,8 @@ static void tpm_crb_none_realize(DeviceState *dev, Error **errp)
         TPM_CRB_ADDR_BASE + sizeof(s->state.regs), &s->state.cmdmem);
 
     if (s->state.ppi_enabled) {
-        tpm_ppi_init(&s->state.ppi, get_system_memory(),
-                     TPM_PPI_ADDR_BASE, OBJECT(s));
+        memory_region_add_subregion(get_system_memory(),
+            TPM_PPI_ADDR_BASE, &s->state.ppi.ram);
     }
 
     if (xen_enabled()) {
diff --git a/hw/tpm/tpm_crb_common.c b/hw/tpm/tpm_crb_common.c
index 01b35808f6..bee0b71fee 100644
--- a/hw/tpm/tpm_crb_common.c
+++ b/hw/tpm/tpm_crb_common.c
@@ -214,4 +214,7 @@ void tpm_crb_init_memory(Object *obj, TPMCRBState *s, Error **errp)
         "tpm-crb-mmio", sizeof(s->regs));
     memory_region_init_ram(&s->cmdmem, obj,
         "tpm-crb-cmd", CRB_CTRL_CMD_SIZE, errp);
+    if (s->ppi_enabled) {
+        tpm_ppi_init_memory(&s->ppi, obj);
+    }
 }
diff --git a/hw/tpm/tpm_ppi.c b/hw/tpm/tpm_ppi.c
index 7f74e26ec6..40cab59afa 100644
--- a/hw/tpm/tpm_ppi.c
+++ b/hw/tpm/tpm_ppi.c
@@ -44,14 +44,11 @@ void tpm_ppi_reset(TPMPPI *tpmppi)
     }
 }
 
-void tpm_ppi_init(TPMPPI *tpmppi, MemoryRegion *m,
-                  hwaddr addr, Object *obj)
+void tpm_ppi_init_memory(TPMPPI *tpmppi, Object *obj)
 {
     tpmppi->buf = qemu_memalign(qemu_real_host_page_size(),
                                 HOST_PAGE_ALIGN(TPM_PPI_ADDR_SIZE));
     memory_region_init_ram_device_ptr(&tpmppi->ram, obj, "tpm-ppi",
                                       TPM_PPI_ADDR_SIZE, tpmppi->buf);
     vmstate_register_ram(&tpmppi->ram, DEVICE(obj));
-
-    memory_region_add_subregion(m, addr, &tpmppi->ram);
 }
diff --git a/hw/tpm/tpm_tis_isa.c b/hw/tpm/tpm_tis_isa.c
index 0367401586..d596f38c0f 100644
--- a/hw/tpm/tpm_tis_isa.c
+++ b/hw/tpm/tpm_tis_isa.c
@@ -134,8 +134,9 @@ static void tpm_tis_isa_realizefn(DeviceState *dev, Error **errp)
                                 TPM_TIS_ADDR_BASE, &s->mmio);
 
     if (s->ppi_enabled) {
-        tpm_ppi_init(&s->ppi, isa_address_space(ISA_DEVICE(dev)),
-                     TPM_PPI_ADDR_BASE, OBJECT(dev));
+        tpm_ppi_init_memory(&s->ppi, OBJECT(dev));
+        memory_region_add_subregion(isa_address_space(ISA_DEVICE(dev)),
+                                    TPM_PPI_ADDR_BASE, &s->ppi.ram);
     }
 }
 
-- 
2.41.0