Merge branch 'pci/hotplug'

- Fix runtime PM ref imbalance on Hot-Plug Capable ports caused by
  misinterpreting a config read failure after a device has been removed
  (Lukas Wunner)

- Avoid creating a useless PCIe port service device for pciehp if the slot
  is handled by the ACPI hotplug driver (Lukas Wunner)

- Ignore ACPI hotplug slots when calculating depth of pciehp hotplug ports
  (Lukas Wunner)

- Simplify pci_bridge_d3_possible() and clarify comments (Lukas Wunner)

* pci/hotplug:
  PCI: Move is_pciehp check out of pciehp_is_native()
  PCI: pciehp: Use is_pciehp instead of is_hotplug_bridge
  PCI/portdrv: Use is_pciehp instead of is_hotplug_bridge
  PCI/ACPI: Fix runtime PM ref imbalance on Hot-Plug Capable ports

Author: bjorn-helgaas

drivers/pci/hotplug/pciehp_hpc.c

@@ -995,7 +995,7 @@ static inline int pcie_hotplug_depth(struct pci_dev *dev)
 
 	while (bus->parent) {
 		bus = bus->parent;
-		if (bus->self && bus->self->is_hotplug_bridge)
+		if (bus->self && bus->self->is_pciehp)
 			depth++;
 	}
 

drivers/pci/pci-acpi.c

@@ -816,15 +816,10 @@ int pci_acpi_program_hp_params(struct pci_dev *dev)
 bool pciehp_is_native(struct pci_dev *bridge)
 {
 	const struct pci_host_bridge *host;
-	u32 slot_cap;
 
 	if (!IS_ENABLED(CONFIG_HOTPLUG_PCI_PCIE))
 		return false;
 
-	pcie_capability_read_dword(bridge, PCI_EXP_SLTCAP, &slot_cap);
-	if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
-		return false;
-
 	if (pcie_ports_native)
 		return true;
 
@@ -1002,7 +997,7 @@ bool acpi_pci_bridge_d3(struct pci_dev *dev)
 	struct acpi_device *adev, *rpadev;
 	const union acpi_object *obj;
 
-	if (acpi_pci_disabled || !dev->is_hotplug_bridge)
+	if (acpi_pci_disabled || !dev->is_pciehp)
 		return false;
 
 	adev = ACPI_COMPANION(&dev->dev);

drivers/pci/pci.c

@@ -3030,8 +3030,12 @@ static const struct dmi_system_id bridge_d3_blacklist[] = {
  * pci_bridge_d3_possible - Is it possible to put the bridge into D3
  * @bridge: Bridge to check
  *
- * This function checks if it is possible to move the bridge to D3.
  * Currently we only allow D3 for some PCIe ports and for Thunderbolt.
+ *
+ * Return: Whether it is possible to move the bridge to D3.
+ *
+ * The return value is guaranteed to be constant across the entire lifetime
+ * of the bridge, including its hot-removal.
  */
 bool pci_bridge_d3_possible(struct pci_dev *bridge)
 {
@@ -3046,10 +3050,14 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
 			return false;
 
 		/*
-		 * Hotplug ports handled by firmware in System Management Mode
-		 * may not be put into D3 by the OS (Thunderbolt on non-Macs).
+		 * Hotplug ports handled by platform firmware may not be put
+		 * into D3 by the OS, e.g. ACPI slots ...
 		 */
-		if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge))
+		if (bridge->is_hotplug_bridge && !bridge->is_pciehp)
+			return false;
+
+		/* ... or PCIe hotplug ports not handled natively by the OS. */
+		if (bridge->is_pciehp && !pciehp_is_native(bridge))
 			return false;
 
 		if (pci_bridge_d3_force)
@@ -3068,7 +3076,7 @@ bool pci_bridge_d3_possible(struct pci_dev *bridge)
 		 * by vendors for runtime D3 at least until 2018 because there
 		 * was no OS support.
 		 */
-		if (bridge->is_hotplug_bridge)
+		if (bridge->is_pciehp)
 			return false;
 
 		if (dmi_check_system(bridge_d3_blacklist))

drivers/pci/pcie/portdrv.c

@@ -220,7 +220,7 @@ static int get_port_device_capability(struct pci_dev *dev)
 	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
 	int services = 0;
 
-	if (dev->is_hotplug_bridge &&
+	if (dev->is_pciehp &&
 	    (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
 	     pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) &&
 	    (pcie_ports_native || host->native_pcie_hotplug)) {

drivers/pci/probe.c

@@ -1678,7 +1678,7 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev)
 
 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32);
 	if (reg32 & PCI_EXP_SLTCAP_HPC)
-		pdev->is_hotplug_bridge = 1;
+		pdev->is_hotplug_bridge = pdev->is_pciehp = 1;
 }
 
 static void set_pcie_thunderbolt(struct pci_dev *dev)

include/linux/pci.h

@@ -328,6 +328,11 @@ struct rcec_ea;
  *			determined (e.g., for Root Complex Integrated
  *			Endpoints without the relevant Capability
  *			Registers).
+ * @is_hotplug_bridge:	Hotplug bridge of any kind (e.g. PCIe Hot-Plug Capable,
+ *			Conventional PCI Hot-Plug, ACPI slot).
+ *			Such bridges are allocated additional MMIO and bus
+ *			number resources to allow for hierarchy expansion.
+ * @is_pciehp:		PCIe Hot-Plug Capable bridge.
  */
 struct pci_dev {
 	struct list_head bus_list;	/* Node in per-bus list */
@@ -451,6 +456,7 @@ struct pci_dev {
 	unsigned int	is_physfn:1;
 	unsigned int	is_virtfn:1;
 	unsigned int	is_hotplug_bridge:1;
+	unsigned int	is_pciehp:1;
 	unsigned int	shpc_managed:1;		/* SHPC owned by shpchp */
 	unsigned int	is_thunderbolt:1;	/* Thunderbolt controller */
 	/*

include/linux/pci_hotplug.h

@@ -104,6 +104,7 @@ static inline bool shpchp_is_native(struct pci_dev *bridge) { return true; }
 
 static inline bool hotplug_is_native(struct pci_dev *bridge)
 {
-	return pciehp_is_native(bridge) || shpchp_is_native(bridge);
+	return (bridge->is_pciehp && pciehp_is_native(bridge)) ||
+	       shpchp_is_native(bridge);
 }
 #endif