1 files changed, 62 insertions, 43 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2127aba3550b..fba95486caaf 100644
--- a/drivers/pci/pci.c
+++ b/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;
-	int domain = -1;
+	static bool static_domains_reserved = false;
+	int domain_nr;
 
-	if (parent)
-		domain = of_get_pci_domain_nr(parent->of_node);
+	/* On the first call scan device tree for static allocations. */
+	if (!static_domains_reserved) {
+		of_pci_reserve_static_domain_nr();
+		static_domains_reserved = true;
+	}
+
+	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);
+	}
 
 	/*
-	 * 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 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.
 	 */
-	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 ida_alloc(&pci_domain_nr_dynamic_ida, GFP_KERNEL);
+}
 
-	return domain;
+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
 
 /**