Merge branch 'pci/enumeration'

- Only read/write PCIe Link 2 registers for devices with Links and PCIe
  Capability version >= 2 (Maciej W. Rozycki)

- Revert a patch that cleared PCI_STATUS during enumeration because it
  broke Linux guests on Apple's virtualization framework (Bjorn Helgaas)

- Assign PCI domain IDs using IDAs so IDs can be easily reused after
  loading/unloading host bridge drivers (Pali Rohár)

- Fix pci_device_is_present(), which previously always returned "false" for
  VFs because their vendor ID is always 0xfff (Michael S. Tsirkin)

- Check for alloc failure in pci_request_irq() (Zeng Heng)

* pci/enumeration:
  PCI: Check for alloc failure in pci_request_irq()
  PCI: Fix pci_device_is_present() for VFs by checking PF
  PCI: Assign PCI domain IDs by ida_alloc()
  Revert "PCI: Clear PCI_STATUS when setting up device"
  PCI: Access Link 2 registers only for devices with Links

drivers/pci/access.c

@@ -350,6 +350,11 @@ bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
 	       type == PCI_EXP_TYPE_PCIE_BRIDGE;
 }
 
+bool pcie_cap_has_lnkctl2(const struct pci_dev *dev)
+{
+	return pcie_cap_has_lnkctl(dev) && pcie_cap_version(dev) > 1;
+}
+
 static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
 {
 	return pcie_downstream_port(dev) &&
@@ -390,10 +395,11 @@ static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
 		return pcie_cap_has_rtctl(dev);
 	case PCI_EXP_DEVCAP2:
 	case PCI_EXP_DEVCTL2:
+		return pcie_cap_version(dev) > 1;
 	case PCI_EXP_LNKCAP2:
 	case PCI_EXP_LNKCTL2:
 	case PCI_EXP_LNKSTA2:
-		return pcie_cap_version(dev) > 1;
+		return pcie_cap_has_lnkctl2(dev);
 	default:
 		return false;
 	}

drivers/pci/irq.c

@@ -44,6 +44,8 @@ int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
 	va_start(ap, fmt);
 	devname = kvasprintf(GFP_KERNEL, fmt, ap);
 	va_end(ap);
+	if (!devname)
+		return -ENOMEM;
 
 	ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
 				   irqflags, devname, dev_id);

drivers/pci/pci.c

@@ -6447,6 +6447,8 @@ bool pci_device_is_present(struct pci_dev *pdev)
 {
 	u32 v;
 
+	/* Check PF if pdev is a VF, since VF Vendor/Device IDs are 0xffff */
+	pdev = pci_physfn(pdev);
 	if (pci_dev_is_disconnected(pdev))
 		return false;
 	return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0);
@@ -6743,60 +6745,70 @@ static void pci_no_domains(void)
 }
 
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
-static atomic_t __domain_nr = ATOMIC_INIT(-1);
+static DEFINE_IDA(pci_domain_nr_static_ida);
+static DEFINE_IDA(pci_domain_nr_dynamic_ida);
 
-static int pci_get_new_domain_nr(void)
+static void of_pci_reserve_static_domain_nr(void)
 {
-	return atomic_inc_return(&__domain_nr);
+	struct device_node *np;
+	int domain_nr;
+
+	for_each_node_by_type(np, "pci") {
+		domain_nr = of_get_pci_domain_nr(np);
+		if (domain_nr < 0)
+			continue;
+		/*
+		 * Permanently allocate domain_nr in dynamic_ida
+		 * to prevent it from dynamic allocation.
+		 */
+		ida_alloc_range(&pci_domain_nr_dynamic_ida,
+				domain_nr, domain_nr, GFP_KERNEL);
+	}
 }
 
 static int of_pci_bus_find_domain_nr(struct device *parent)
 {
-	static int use_dt_domains = -1;
+	static bool static_domains_reserved = false;
-	int domain = -1;
+	int domain_nr;
 
-	if (parent)
+	/* On the first call scan device tree for static allocations. */
-		domain = of_get_pci_domain_nr(parent->of_node);
+	if (!static_domains_reserved) {
-
+		of_pci_reserve_static_domain_nr();
-	/*
+		static_domains_reserved = true;
-	 * Check DT domain and use_dt_domains values.
-	 *
-	 * If DT domain property is valid (domain >= 0) and
-	 * use_dt_domains != 0, the DT assignment is valid since this means
-	 * we have not previously allocated a domain number by using
-	 * pci_get_new_domain_nr(); we should also update use_dt_domains to
-	 * 1, to indicate that we have just assigned a domain number from
-	 * DT.
-	 *
-	 * If DT domain property value is not valid (ie domain < 0), and we
-	 * have not previously assigned a domain number from DT
-	 * (use_dt_domains != 1) we should assign a domain number by
-	 * using the:
-	 *
-	 * pci_get_new_domain_nr()
-	 *
-	 * API and update the use_dt_domains value to keep track of method we
-	 * are using to assign domain numbers (use_dt_domains = 0).
-	 *
-	 * All other combinations imply we have a platform that is trying
-	 * to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
-	 * which is a recipe for domain mishandling and it is prevented by
-	 * invalidating the domain value (domain = -1) and printing a
-	 * corresponding error.
-	 */
-	if (domain >= 0 && use_dt_domains) {
-		use_dt_domains = 1;
-	} else if (domain < 0 && use_dt_domains != 1) {
-		use_dt_domains = 0;
-		domain = pci_get_new_domain_nr();
-	} else {
-		if (parent)
-			pr_err("Node %pOF has ", parent->of_node);
-		pr_err("Inconsistent \"linux,pci-domain\" property in DT\n");
-		domain = -1;
 	}
 
-	return domain;
+	if (parent) {
+		/*
+		 * If domain is in DT, allocate it in static IDA.  This
+		 * prevents duplicate static allocations in case of errors
+		 * in DT.
+		 */
+		domain_nr = of_get_pci_domain_nr(parent->of_node);
+		if (domain_nr >= 0)
+			return ida_alloc_range(&pci_domain_nr_static_ida,
+					       domain_nr, domain_nr,
+					       GFP_KERNEL);
+	}
+
+	/*
+	 * If domain was not specified in DT, choose a free ID from dynamic
+	 * allocations. All domain numbers from DT are permanently in
+	 * dynamic allocations to prevent assigning them to other DT nodes
+	 * without static domain.
+	 */
+	return ida_alloc(&pci_domain_nr_dynamic_ida, GFP_KERNEL);
+}
+
+static void of_pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+	if (bus->domain_nr < 0)
+		return;
+
+	/* Release domain from IDA where it was allocated. */
+	if (of_get_pci_domain_nr(parent->of_node) == bus->domain_nr)
+		ida_free(&pci_domain_nr_static_ida, bus->domain_nr);
+	else
+		ida_free(&pci_domain_nr_dynamic_ida, bus->domain_nr);
 }
 
 int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
@@ -6804,6 +6816,13 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)
 	return acpi_disabled ? of_pci_bus_find_domain_nr(parent) :
 			       acpi_pci_bus_find_domain_nr(bus);
 }
+
+void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+	if (!acpi_disabled)
+		return;
+	of_pci_bus_release_domain_nr(bus, parent);
+}
 #endif
 
 /**

drivers/pci/pci.h

@@ -15,6 +15,7 @@ extern const unsigned char pcie_link_speed[];
 extern bool pci_early_dump;
 
 bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
+bool pcie_cap_has_lnkctl2(const struct pci_dev *dev);
 bool pcie_cap_has_rtctl(const struct pci_dev *dev);
 
 /* Functions internal to the PCI core code */

drivers/pci/probe.c

@@ -906,6 +906,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge)
 		bus->domain_nr = pci_bus_find_domain_nr(bus, parent);
 	else
 		bus->domain_nr = bridge->domain_nr;
+	if (bus->domain_nr < 0) {
+		err = bus->domain_nr;
+		goto free;
+	}
 #endif
 
 	b = pci_find_bus(pci_domain_nr(bus), bridge->busnr);
@@ -1030,6 +1034,9 @@ unregister:
 	device_del(&bridge->dev);
 
 free:
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+	pci_bus_release_domain_nr(bus, parent);
+#endif
 	kfree(bus);
 	return err;
 }
@@ -1891,9 +1898,6 @@ int pci_setup_device(struct pci_dev *dev)
 
 	dev->broken_intx_masking = pci_intx_mask_broken(dev);
 
-	/* Clear errors left from system firmware */
-	pci_write_config_word(dev, PCI_STATUS, 0xffff);
-
 	switch (dev->hdr_type) {		    /* header type */
 	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
 		if (class == PCI_CLASS_BRIDGE_PCI)

drivers/pci/remove.c

@@ -160,6 +160,12 @@ void pci_remove_root_bus(struct pci_bus *bus)
 	pci_remove_bus(bus);
 	host_bridge->bus = NULL;
 
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+	/* Release domain_nr if it was dynamically allocated */
+	if (host_bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET)
+		pci_bus_release_domain_nr(bus, host_bridge->dev.parent);
+#endif
+
 	/* remove the host bridge */
 	device_del(&host_bridge->dev);
 }

include/linux/pci.h

@@ -1726,6 +1726,7 @@ static inline int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
 { return 0; }
 #endif
 int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent);
+void pci_bus_release_domain_nr(struct pci_bus *bus, struct device *parent);
 #endif
 
 /* Some architectures require additional setup to direct VGA traffic */