ppc/pnv: assign pnv-phb-root-port chassis/slot earlier

It is not advisable to execute an object_dynamic_cast() to poke into
bus->qbus.parent and follow it up with a C cast into the PnvPHB type we
think we got.

In fact this is not needed. There is nothing sophisticated being done
with the PHB object retrieved during root_port_realize() for both PHB3
and PHB4. We're retrieving a PHB reference just to access phb->chip_id
and phb->phb_id and use them to define the chassis/slot of the root
port.

phb->phb_id is already being passed to pnv_phb_attach_root_port() via
the 'index' parameter. Let's also add a 'chip_id' parameter to this
function and assign chassis and slot right there. This will spare us
from the hassle of accessing the PHB object inside realize().

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Message-Id: <20220621173436.165912-4-danielhb413@gmail.com>

hw/pci-host/pnv_phb3.c

@@ -1052,7 +1052,8 @@ static void pnv_phb3_realize(DeviceState *dev, Error **errp)
 
     pci_setup_iommu(pci->bus, pnv_phb3_dma_iommu, phb);
 
-    pnv_phb_attach_root_port(pci, TYPE_PNV_PHB3_ROOT_PORT, phb->phb_id);
+    pnv_phb_attach_root_port(pci, TYPE_PNV_PHB3_ROOT_PORT,
+                             phb->phb_id, phb->chip_id);
 }
 
 void pnv_phb3_update_regions(PnvPHB3 *phb)
@@ -1139,23 +1140,8 @@ static void pnv_phb3_root_port_realize(DeviceState *dev, Error **errp)
 {
     PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(dev);
     PCIDevice *pci = PCI_DEVICE(dev);
-    PCIBus *bus = pci_get_bus(pci);
-    PnvPHB3 *phb = NULL;
     Error *local_err = NULL;
 
-    phb = (PnvPHB3 *) object_dynamic_cast(OBJECT(bus->qbus.parent),
-                                          TYPE_PNV_PHB3);
-
-    if (!phb) {
-        error_setg(errp,
-"pnv_phb3_root_port devices must be connected to pnv-phb3 buses");
-        return;
-    }
-
-    /* Set unique chassis/slot values for the root port */
-    qdev_prop_set_uint8(&pci->qdev, "chassis", phb->chip_id);
-    qdev_prop_set_uint16(&pci->qdev, "slot", phb->phb_id);
-
     rpc->parent_realize(dev, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);

hw/pci-host/pnv_phb4.c

@@ -1585,7 +1585,8 @@ static void pnv_phb4_realize(DeviceState *dev, Error **errp)
     pci->bus->flags |= PCI_BUS_EXTENDED_CONFIG_SPACE;
 
     /* Add a single Root port if running with defaults */
-    pnv_phb_attach_root_port(pci, pecc->rp_model, phb->phb_id);
+    pnv_phb_attach_root_port(pci, pecc->rp_model,
+                             phb->phb_id, phb->chip_id);
 
     /* Setup XIVE Source */
     if (phb->big_phb) {
@@ -1781,23 +1782,8 @@ static void pnv_phb4_root_port_reset(DeviceState *dev)
 static void pnv_phb4_root_port_realize(DeviceState *dev, Error **errp)
 {
     PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(dev);
-    PCIDevice *pci = PCI_DEVICE(dev);
-    PCIBus *bus = pci_get_bus(pci);
-    PnvPHB4 *phb = NULL;
     Error *local_err = NULL;
 
-    phb = (PnvPHB4 *) object_dynamic_cast(OBJECT(bus->qbus.parent),
-                                          TYPE_PNV_PHB4);
-
-    if (!phb) {
-        error_setg(errp, "%s must be connected to pnv-phb4 buses", dev->id);
-        return;
-    }
-
-    /* Set unique chassis/slot values for the root port */
-    qdev_prop_set_uint8(&pci->qdev, "chassis", phb->chip_id);
-    qdev_prop_set_uint16(&pci->qdev, "slot", phb->phb_id);
-
     rpc->parent_realize(dev, &local_err);
     if (local_err) {
         error_propagate(errp, local_err);

hw/ppc/pnv.c

@@ -1189,8 +1189,15 @@ static void pnv_chip_icp_realize(Pnv8Chip *chip8, Error **errp)
     }
 }
 
-/* Attach a root port device */
+/*
-void pnv_phb_attach_root_port(PCIHostState *pci, const char *name, int index)
+ * Attach a root port device.
+ *
+ * 'index' will be used both as a PCIE slot value and to calculate
+ * QOM id. 'chip_id' is going to be used as PCIE chassis for the
+ * root port.
+ */
+void pnv_phb_attach_root_port(PCIHostState *pci, const char *name,
+                              int index, int chip_id)
 {
     PCIDevice *root = pci_new(PCI_DEVFN(0, 0), name);
     g_autofree char *default_id = g_strdup_printf("%s[%d]", name, index);
@@ -1199,6 +1206,10 @@ void pnv_phb_attach_root_port(PCIHostState *pci, const char *name, int index)
     object_property_add_child(OBJECT(pci->bus), dev_id ? dev_id : default_id,
                               OBJECT(root));
 
+    /* Set unique chassis/slot values for the root port */
+    qdev_prop_set_uint8(DEVICE(root), "chassis", chip_id);
+    qdev_prop_set_uint16(DEVICE(root), "slot", index);
+
     pci_realize_and_unref(root, pci->bus, &error_fatal);
 }
 

include/hw/ppc/pnv.h

@@ -189,7 +189,8 @@ DECLARE_INSTANCE_CHECKER(PnvChip, PNV_CHIP_POWER10,
                          TYPE_PNV_CHIP_POWER10)
 
 PowerPCCPU *pnv_chip_find_cpu(PnvChip *chip, uint32_t pir);
-void pnv_phb_attach_root_port(PCIHostState *pci, const char *name, int index);
+void pnv_phb_attach_root_port(PCIHostState *pci, const char *name,
+                              int index, int chip_id);
 
 #define TYPE_PNV_MACHINE       MACHINE_TYPE_NAME("powernv")
 typedef struct PnvMachineClass PnvMachineClass;