[PATCH for-7.2 04/10] ppc/pnv: add helpers for pnv-phb user devices

[Daniel Henrique Barboza <danielhb413@gmail.com>]

pnv_parent_qom_fixup() and pnv_parent_bus_fixup() are versions of the
helpers that were reverted by commit 9c10d86fee "ppc/pnv: Remove
user-created PHB{3,4,5} devices". They are needed to amend the QOM and
bus hierarchies of user created pnv-phbs, matching them with default
pnv-phbs.

A new helper pnv_phb_user_device_init() is created to handle
user-created devices setup. We're going to call it inside
pnv_phb_realize() in case we're realizing an user created device. This
will centralize all user device realated in a single spot, leaving the
realize functions of the phb3/phb4 backends untouched.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
---
 hw/pci-host/pnv_phb.c | 69 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/hw/pci-host/pnv_phb.c b/hw/pci-host/pnv_phb.c
index 826c0c144e..da779dc298 100644
--- a/hw/pci-host/pnv_phb.c
+++ b/hw/pci-host/pnv_phb.c
@@ -18,6 +18,37 @@
 #include "hw/qdev-properties.h"
 #include "qom/object.h"
 
+
+/*
+ * Set the QOM parent of an object child. If the device state
+ * associated with the child has an id, use it as QOM id. Otherwise
+ * use object_typename[index] as QOM id.
+ */
+static void pnv_parent_qom_fixup(Object *parent, Object *child, int index)
+{
+    g_autofree char *default_id =
+        g_strdup_printf("%s[%d]", object_get_typename(child), index);
+    const char *dev_id = DEVICE(child)->id;
+
+    if (child->parent == parent) {
+        return;
+    }
+
+    object_ref(child);
+    object_unparent(child);
+    object_property_add_child(parent, dev_id ? dev_id : default_id, child);
+    object_unref(child);
+}
+
+static void pnv_parent_bus_fixup(DeviceState *parent, DeviceState *child)
+{
+    BusState *parent_bus = qdev_get_parent_bus(parent);
+
+    if (!qdev_set_parent_bus(child, parent_bus, &error_fatal)) {
+        return;
+    }
+}
+
 /*
  * Attach a root port device.
  *
@@ -41,6 +72,36 @@ static void pnv_phb_attach_root_port(PCIHostState *pci)
     pci_realize_and_unref(root, pci->bus, &error_fatal);
 }
 
+/*
+ * User created devices won't have the initial setup that default
+ * devices have. This setup consists of assigning a parent device
+ * (chip for PHB3, PEC for PHB4/5) that will be the QOM/bus parent
+ * of the PHB.
+ */
+static void pnv_phb_user_device_init(PnvPHB *phb)
+{
+    PnvMachineState *pnv = PNV_MACHINE(qdev_get_machine());
+    PnvChip *chip = pnv_get_chip(pnv, phb->chip_id);
+    Object *parent = NULL;
+
+    if (!chip) {
+        error_setg(&error_fatal, "invalid chip id: %d", phb->chip_id);
+        return;
+    }
+
+    /*
+     * Reparent user created devices to the chip to build
+     * correctly the device tree. pnv_xscom_dt() needs every
+     * PHB to be a child of the chip to build the DT correctly.
+     *
+     * TODO: for version 3 we're still parenting the PHB with the
+     * chip. We should parent with a (so far not implemented)
+     * PHB3 PEC device.
+     */
+    pnv_parent_qom_fixup(parent, OBJECT(phb), phb->phb_id);
+    pnv_parent_bus_fixup(DEVICE(chip), DEVICE(phb));
+}
+
 static void pnv_phb_realize(DeviceState *dev, Error **errp)
 {
     PnvPHB *phb = PNV_PHB(dev);
@@ -74,6 +135,14 @@ static void pnv_phb_realize(DeviceState *dev, Error **errp)
     object_property_set_uint(phb->backend, "chip-id", phb->chip_id, errp);
     object_property_set_link(phb->backend, "phb-base", OBJECT(phb), errp);
 
+    /*
+     * Handle user created devices. User devices will not have a
+     * pointer to a chip (PHB3) and a PEC (PHB4/5).
+     */
+    if (!phb->chip && !phb->pec) {
+        pnv_phb_user_device_init(phb);
+    }
+
     if (phb->version == 3) {
         object_property_set_link(phb->backend, "chip",
                                  OBJECT(phb->chip), errp);
-- 
2.36.1