diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 638e79d10bfab..3085ecaa2ba40 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -382,9 +382,11 @@ void pci_bus_add_devices(const struct pci_bus *bus)
 		/* Skip if device attach failed */
 		if (!pci_dev_is_added(dev))
 			continue;
-		child = dev->subordinate;
+
+		child = pci_dev_get_subordinate(dev);
 		if (child)
 			pci_bus_add_devices(child);
+		pci_bus_put(child);
 	}
 }
 EXPORT_SYMBOL(pci_bus_add_devices);
@@ -396,11 +398,16 @@ static int __pci_walk_bus(struct pci_bus *top, int (*cb)(struct pci_dev *, void
 	int ret = 0;
 
 	list_for_each_entry(dev, &top->devices, bus_list) {
+		struct pci_bus *bus;
+
 		ret = cb(dev, userdata);
 		if (ret)
 			break;
-		if (dev->subordinate) {
-			ret = __pci_walk_bus(dev->subordinate, cb, userdata);
+
+		bus = pci_dev_get_subordinate(dev);
+		if (bus) {
+			ret = __pci_walk_bus(bus, cb, userdata);
+			pci_bus_put(bus);
 			if (ret)
 				break;
 		}
@@ -448,3 +455,8 @@ void pci_bus_put(struct pci_bus *bus)
 	if (bus)
 		put_device(&bus->dev);
 }
+
+struct pci_bus *pci_dev_get_subordinate(struct pci_dev *dev)
+{
+	return pci_bus_get(READ_ONCE(dev->subordinate));
+}
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 65e50bee1a8c0..b15dcfd86c60a 100644
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -33,9 +33,12 @@ int pciehp_configure_device(struct controller *ctrl)
 {
 	struct pci_dev *dev;
 	struct pci_dev *bridge = ctrl->pcie->port;
-	struct pci_bus *parent = bridge->subordinate;
+	struct pci_bus *parent = pci_dev_get_subordinate(bridge);
 	int num, ret = 0;
 
+	if (!parent)
+		return 0;
+
 	pci_lock_rescan_remove();
 
 	dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
@@ -78,6 +81,7 @@ int pciehp_configure_device(struct controller *ctrl)
 
  out:
 	pci_unlock_rescan_remove();
+	pci_bus_put(parent);
 	return ret;
 }
 
@@ -95,9 +99,12 @@ int pciehp_configure_device(struct controller *ctrl)
 void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
 {
 	struct pci_dev *dev, *temp;
-	struct pci_bus *parent = ctrl->pcie->port->subordinate;
+	struct pci_bus *parent = pci_dev_get_subordinate(ctrl->pcie->port);
 	u16 command;
 
+	if (!parent)
+		return;
+
 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
 		 __func__, pci_domain_nr(parent), parent->number);
 
@@ -138,4 +145,5 @@ void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
 	}
 
 	pci_unlock_rescan_remove();
+	pci_bus_put(parent);
 }
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e3a49f66982d5..0cd36b7772c8b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3113,9 +3113,14 @@ void pci_bridge_d3_update(struct pci_dev *dev)
 	 * so we need to go through all children to find out if one of them
 	 * continues to block D3.
 	 */
-	if (d3cold_ok && !bridge->bridge_d3)
-		pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold,
-			     &d3cold_ok);
+	if (d3cold_ok && !bridge->bridge_d3) {
+		struct pci_bus *bus = pci_dev_get_subordinate(bridge);
+
+		if (bus) {
+			pci_walk_bus(bus, pci_dev_check_d3cold, &d3cold_ok);
+			pci_bus_put(bus);
+		}
+	}
 
 	if (bridge->bridge_d3 != d3cold_ok) {
 		bridge->bridge_d3 = d3cold_ok;
@@ -4824,6 +4829,7 @@ static int pci_bus_max_d3cold_delay(const struct pci_bus *bus)
 int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
 {
 	struct pci_dev *child __free(pci_dev_put) = NULL;
+	struct pci_bus *bus;
 	int delay;
 
 	if (pci_dev_is_disconnected(dev))
@@ -4840,7 +4846,17 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
 	 * board_added(). In case of ACPI hotplug the firmware is expected
 	 * to configure the devices before OS is notified.
 	 */
-	if (!dev->subordinate || list_empty(&dev->subordinate->devices)) {
+	bus = pci_dev_get_subordinate(dev);
+	if (!bus) {
+		up_read(&pci_bus_sem);
+		return 0;
+	}
+
+	child = pci_dev_get(list_first_entry_or_null(&bus->devices,
+						     struct pci_dev,
+						     bus_list));
+	if (!child) {
+		pci_bus_put(bus);
 		up_read(&pci_bus_sem);
 		return 0;
 	}
@@ -4848,12 +4864,12 @@ int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type)
 	/* Take d3cold_delay requirements into account */
 	delay = pci_bus_max_d3cold_delay(dev->subordinate);
 	if (!delay) {
+		pci_bus_put(bus);
 		up_read(&pci_bus_sem);
 		return 0;
 	}
 
-	child = pci_dev_get(list_first_entry(&dev->subordinate->devices,
-					     struct pci_dev, bus_list));
+	pci_bus_put(bus);
 	up_read(&pci_bus_sem);
 
 	/*
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 19cbf18743a96..83e449253066e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -312,6 +312,7 @@ void pci_reassigndev_resource_alignment(struct pci_dev *dev);
 void pci_disable_bridge_window(struct pci_dev *dev);
 struct pci_bus *pci_bus_get(struct pci_bus *bus);
 void pci_bus_put(struct pci_bus *bus);
+struct pci_bus *pci_dev_get_subordinate(struct pci_dev *dev);
 
 /* PCIe link information from Link Capabilities 2 */
 #define PCIE_LNKCAP2_SLS2SPEED(lnkcap2) \
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index cee2365e54b8b..3c0c83d35ab86 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -1212,9 +1212,11 @@ static void pcie_update_aspm_capable(struct pcie_link_state *root)
 		link->aspm_capable = link->aspm_support;
 	}
 	list_for_each_entry(link, &link_list, sibling) {
+		struct pci_bus *linkbus;
 		struct pci_dev *child;
-		struct pci_bus *linkbus = link->pdev->subordinate;
-		if (link->root != root)
+
+		linkbus = pci_dev_get_subordinate(link->pdev);
+		if (!linkbus || link->root != root)
 			continue;
 		list_for_each_entry(child, &linkbus->devices, bus_list) {
 			if ((pci_pcie_type(child) != PCI_EXP_TYPE_ENDPOINT) &&
@@ -1222,6 +1224,7 @@ static void pcie_update_aspm_capable(struct pcie_link_state *root)
 				continue;
 			pcie_aspm_check_latency(child);
 		}
+		pci_bus_put(linkbus);
 	}
 }
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b14b9876c0303..53522685193da 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1167,7 +1167,10 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
 		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
 		child->resource[i]->name = child->name;
 	}
-	bridge->subordinate = child;
+
+	down_write(&pci_bus_sem);
+	WRITE_ONCE(bridge->subordinate, child);
+	up_write(&pci_bus_sem);
 
 add_dev:
 	pci_set_bus_msi_domain(child);
@@ -3380,7 +3383,7 @@ int pci_hp_add_bridge(struct pci_dev *dev)
 	/* Scan bridges that need to be reconfigured */
 	pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1);
 
-	if (!dev->subordinate)
+	if (!READ_ONCE(dev->subordinate))
 		return -1;
 
 	return 0;
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index 288162a11ab19..646c97e41a323 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -77,10 +77,12 @@ EXPORT_SYMBOL(pci_remove_bus);
 
 static void pci_stop_bus_device(struct pci_dev *dev)
 {
-	struct pci_bus *bus = dev->subordinate;
+	struct pci_bus *bus = pci_dev_get_subordinate(dev);
 
-	if (bus)
+	if (bus) {
 		pci_stop_bus(bus);
+		pci_bus_put(bus);
+	}
 	pci_stop_dev(dev);
 }
 
@@ -100,12 +102,18 @@ static void pci_stop_bus(struct pci_bus *bus)
 
 static void pci_remove_bus_device(struct pci_dev *dev)
 {
-	struct pci_bus *bus = dev->subordinate;
+	struct pci_bus *bus;
 
+	down_write(&pci_bus_sem);
+	bus = pci_dev_get_subordinate(dev);
 	if (bus) {
+		WRITE_ONCE(dev->subordinate, NULL);
+		up_write(&pci_bus_sem);
+
 		pci_remove_bus(bus);
-		dev->subordinate = NULL;
-	}
+		pci_bus_put(bus);
+	} else
+		up_write(&pci_bus_sem);
 	pci_destroy_dev(dev);
 }
 
