pnv_phb4_pec: Simplify/align code to parent user-created PHBs

When instantiating a user-created PHB on P9/P10, we don't really have
a reason any more to go through an indirection in pnv_chip_add_phb()
in pnv.c, we can go straight to the right function in
pnv_phb4_pec.c. That way, default PHBs and user-created PHBs are all
handled in the same file.  This patch also renames pnv_phb4_get_pec()
to pnv_pec_add_phb() to better reflect that it "hooks" a PHB to a PEC.

For P8, the PHBs are parented to the chip directly, so it makes sense
to keep calling pnv_chip_add_phb() in pnv.c, to also be consistent
with where default PHBs are handled. The only change here is that,
since that function is now only used for P8, we can refine the return
type.

So overall, the PnvPHB front-end now has a pnv_phb_user_get_parent()
function which handles the parenting of the user-created PHBs by
calling the right function in the right file based on the processor
version. It's also easily extensible if we ever need to support a
different parent object.

Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Message-Id: <20230302163715.129635-5-fbarrat@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

hw/pci-host/pnv_phb.c

@@ -62,6 +62,15 @@ static bool pnv_parent_fixup(Object *parent, BusState *parent_bus,
     return true;
 }
 
+static Object *pnv_phb_user_get_parent(PnvChip *chip, PnvPHB *phb, Error **errp)
+{
+    if (phb->version == 3) {
+        return OBJECT(pnv_chip_add_phb(chip, phb));
+    } else {
+        return OBJECT(pnv_pec_add_phb(chip, phb, errp));
+    }
+}
+
 /*
  * User created devices won't have the initial setup that default
  * devices have. This setup consists of assigning a parent device
@@ -79,7 +88,7 @@ static bool pnv_phb_user_device_init(PnvPHB *phb, Error **errp)
         return false;
     }
 
-    parent = pnv_chip_add_phb(chip, phb, errp);
+    parent = pnv_phb_user_get_parent(chip, phb, errp);
     if (!parent) {
         return false;
     }

hw/pci-host/pnv_phb4_pec.c

@@ -112,7 +112,7 @@ static const MemoryRegionOps pnv_pec_pci_xscom_ops = {
     .endianness = DEVICE_BIG_ENDIAN,
 };
 
-PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB *phb, Error **errp)
+PnvPhb4PecState *pnv_pec_add_phb(PnvChip *chip, PnvPHB *phb, Error **errp)
 {
     PnvPhb4PecState *pecs = NULL;
     int chip_id = phb->chip_id;
@@ -141,6 +141,7 @@ PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB *phb, Error **errp)
         for (j = 0; j < pec->num_phbs; j++) {
             if (index == pnv_phb4_pec_get_phb_id(pec, j)) {
                 pec->phbs[j] = phb;
+                phb->pec = pec;
                 return pec;
             }
         }

hw/ppc/pnv.c

@@ -285,31 +285,18 @@ static void pnv_dt_icp(PnvChip *chip, void *fdt, uint32_t pir,
 }
 
 /*
- * Adds a PnvPHB to the chip. Returns the parent obj of the
- * PHB which varies with each version (phb version 3 is parented
- * by the chip, version 4 and 5 are parented by the PEC
- * device).
- *
- * 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.
+ * Adds a PnvPHB to the chip on P8.
+ * Implemented here, like for defaults PHBs
  */
-Object *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb, Error **errp)
+PnvChip *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb)
 {
-    if (phb->version == 3) {
-        Pnv8Chip *chip8 = PNV8_CHIP(chip);
+    Pnv8Chip *chip8 = PNV8_CHIP(chip);
 
-        phb->chip = chip;
+    phb->chip = chip;
 
-        chip8->phbs[chip8->num_phbs] = phb;
-        chip8->num_phbs++;
-
-        return OBJECT(chip);
-    }
-
-    phb->pec = pnv_phb4_get_pec(chip, phb, errp);
-
-    return OBJECT(phb->pec);
+    chip8->phbs[chip8->num_phbs] = phb;
+    chip8->num_phbs++;
+    return chip;
 }
 
 static void pnv_chip_power8_dt_populate(PnvChip *chip, void *fdt)

include/hw/pci-host/pnv_phb4.h

@@ -157,7 +157,7 @@ struct PnvPHB4 {
 
 void pnv_phb4_pic_print_info(PnvPHB4 *phb, Monitor *mon);
 int pnv_phb4_pec_get_phb_id(PnvPhb4PecState *pec, int stack_index);
-PnvPhb4PecState *pnv_phb4_get_pec(PnvChip *chip, PnvPHB *phb, Error **errp);
+PnvPhb4PecState *pnv_pec_add_phb(PnvChip *chip, PnvPHB *phb, Error **errp);
 void pnv_phb4_bus_init(DeviceState *dev, PnvPHB4 *phb);
 extern const MemoryRegionOps pnv_phb4_xscom_ops;
 

include/hw/ppc/pnv.h

@@ -100,7 +100,7 @@ struct PnvMachineState {
 };
 
 PnvChip *pnv_get_chip(PnvMachineState *pnv, uint32_t chip_id);
-Object *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb, Error **errp);
+PnvChip *pnv_chip_add_phb(PnvChip *chip, PnvPHB *phb);
 
 #define PNV_FDT_ADDR          0x01000000
 #define PNV_TIMEBASE_FREQ     512000000ULL