Merge tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

[platform/kernel/linux-exynos.git] / arch / x86 / pci / acpi.c

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 2ae7ce2..ff99117 100644 (file)
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -338,6 +338,26 @@ static void release_pci_root_info(struct pci_host_bridge *bridge)
        kfree(info);
 }
 
+/*
+ * An IO port or MMIO resource assigned to a PCI host bridge may be
+ * consumed by the host bridge itself or available to its child
+ * bus/devices. The ACPI specification defines a bit (Producer/Consumer)
+ * to tell whether the resource is consumed by the host bridge itself,
+ * but firmware hasn't used that bit consistently, so we can't rely on it.
+ *
+ * On x86 and IA64 platforms, all IO port and MMIO resources are assumed
+ * to be available to child bus/devices except one special case:
+ *     IO port [0xCF8-0xCFF] is consumed by the host bridge itself
+ *     to access PCI configuration space.
+ *
+ * So explicitly filter out PCI CFG IO ports[0xCF8-0xCFF].
+ */
+static bool resource_is_pcicfg_ioport(struct resource *res)
+{
+       return (res->flags & IORESOURCE_IO) &&
+               res->start == 0xCF8 && res->end == 0xCFF;
+}
+
 static void probe_pci_root_info(struct pci_root_info *info,
                                struct acpi_device *device,
                                int busnum, int domain,
@@ -359,8 +379,8 @@ static void probe_pci_root_info(struct pci_root_info *info,
                        "no IO and memory resources present in _CRS\n");
        else
                resource_list_for_each_entry_safe(entry, tmp, list) {
-                       if ((entry->res->flags & IORESOURCE_WINDOW) == 0 ||
-                           (entry->res->flags & IORESOURCE_DISABLED))
+                       if ((entry->res->flags & IORESOURCE_DISABLED) ||
+                           resource_is_pcicfg_ioport(entry->res))
                                resource_list_destroy_entry(entry);
                        else
                                entry->res->name = info->name;
@@ -475,9 +495,16 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 
 int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 {
-       struct pci_sysdata *sd = bridge->bus->sysdata;
-
-       ACPI_COMPANION_SET(&bridge->dev, sd->companion);
+       /*
+        * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
+        * here, pci_create_root_bus() has been called by someone else and
+        * sysdata is likely to be different from what we expect.  Let it go in
+        * that case.
+        */
+       if (!bridge->dev.parent) {
+               struct pci_sysdata *sd = bridge->bus->sysdata;
+               ACPI_COMPANION_SET(&bridge->dev, sd->companion);
+       }
        return 0;
 }