resources: add resource_overlaps()

Add resource_overlaps(), which returns true if two resources overlap at all.

Use this to replace the complicated check in coalesce_windows().

Signed-Off-By: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 8 insertions, 11 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 8a17b23f8c84..fc09c2754e08 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -245,13 +245,6 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
         return AE_OK;
 }
 
-static bool resource_contains(struct resource *res, resource_size_t point)
-{
-        if (res->start <= point && point <= res->end)
-                return true;
-        return false;
-}
-
 static void coalesce_windows(struct pci_root_info *info, unsigned long type)
 {
         int i, j;
@@ -272,10 +265,7 @@ static void coalesce_windows(struct pci_root_info *info, unsigned long type)
                          * our resources no longer match the ACPI _CRS, but
                          * the kernel resource tree doesn't allow overlaps.
                          */
-                        if (resource_contains(res1, res2->start) ||
-                            resource_contains(res1, res2->end) ||
-                            resource_contains(res2, res1->start) ||
-                            resource_contains(res2, res1->end)) {
+                        if (resource_overlaps(res1, res2)) {
                                 res1->start = min(res1->start, res2->start);
                                 res1->end = max(res1->end, res2->end);
                                 dev_info(&info->bridge->dev,
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index e885ba23de70..589e0e75efae 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -223,5 +223,12 @@ extern int
 walk_system_ram_range(unsigned long start_pfn, unsigned long nr_pages,
                 void *arg, int (*func)(unsigned long, unsigned long, void *));
 
+/* True if any part of r1 overlaps r2 */
+static inline bool resource_overlaps(struct resource *r1, struct resource *r2)
+{
+       return (r1->start <= r2->end && r1->end >= r2->start);
+}
+
+
 #endif /* __ASSEMBLY__ */
 #endif  /* _LINUX_IOPORT_H */