core/pci: Use proper phandle during hotplug for PHB slots

PHB slots don't have an associated device (slot->pd = NULL). They were
not used by the PCI hotplug framework so far, but with opencapi
virtual PHBs, that's changing. With opencapi, devices are directly
under the PHB (no root complex or intermediate bridge) and the slot
used for hotplug is the PHB slot.

This patch uses the proper phandle when replying asynchronously to the
OS when using a PHB slot.

Reviewed-by: Christophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>

core/pci-opal.c

@@ -647,6 +647,17 @@ static int64_t opal_pci_get_power_state(uint64_t id, uint64_t data)
 }
 opal_call(OPAL_PCI_GET_POWER_STATE, opal_pci_get_power_state, 2);
 
+static u32 get_slot_phandle(struct pci_slot *slot)
+{
+	struct phb *phb = slot->phb;
+	struct pci_device *pd = slot->pd;
+
+	if (pd)
+		return pd->dn->phandle;
+	else
+		return phb->dt_node->phandle;
+}
+
 static void rescan_slot_devices(struct pci_slot *slot)
 {
 	struct phb *phb = slot->phb;
@@ -671,8 +682,6 @@ static void set_power_timer(struct timer *t __unused, void *data,
 			    uint64_t now __unused)
 {
 	struct pci_slot *slot = data;
-	struct pci_device *pd = slot->pd;
-	struct dt_node *dn = pd->dn;
 	uint8_t link;
 	struct phb *phb = slot->phb;
 
@@ -686,7 +695,7 @@ static void set_power_timer(struct timer *t __unused, void *data,
 		if (slot->retries-- == 0) {
 			pci_slot_set_state(slot, PCI_SLOT_STATE_NORMAL);
 			opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL,
-				       slot->async_token, dn->phandle,
+				       slot->async_token, get_slot_phandle(slot),
 				       slot->power_state, OPAL_BUSY);
 		} else {
 			schedule_timer(&slot->timer, msecs_to_tb(10));
@@ -698,7 +707,7 @@ static void set_power_timer(struct timer *t __unused, void *data,
 			remove_slot_devices(slot);
 			pci_slot_set_state(slot, PCI_SLOT_STATE_NORMAL);
 			opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL,
-				       slot->async_token, dn->phandle,
+				       slot->async_token, get_slot_phandle(slot),
 				       OPAL_PCI_SLOT_POWER_OFF, OPAL_SUCCESS);
 			break;
 		}
@@ -710,12 +719,12 @@ static void set_power_timer(struct timer *t __unused, void *data,
 			rescan_slot_devices(slot);
 			pci_slot_set_state(slot, PCI_SLOT_STATE_NORMAL);
 			opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL,
-				       slot->async_token, dn->phandle,
+				       slot->async_token, get_slot_phandle(slot),
 				       OPAL_PCI_SLOT_POWER_ON, OPAL_SUCCESS);
 		} else if (slot->retries-- == 0) {
 			pci_slot_set_state(slot, PCI_SLOT_STATE_NORMAL);
 			opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, NULL,
-				       slot->async_token, dn->phandle,
+				       slot->async_token, get_slot_phandle(slot),
 				       OPAL_PCI_SLOT_POWER_ON, OPAL_BUSY);
 		} else {
 			schedule_timer(&slot->timer, msecs_to_tb(10));