PCI: Refactor pbus_size_mem()

The original idea comes from Ram Pai.  This patch puts the chunk of
code for calculating the minimal alignment of memory window into a
separate inline function.

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 23 insertions, 13 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index a66cf0905a15..1e808ca338f8 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -812,6 +812,28 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
         }
 }
 
+static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
+                                                  int max_order)
+{
+        resource_size_t align = 0;
+        resource_size_t min_align = 0;
+        int order;
+
+        for (order = 0; order <= max_order; order++) {
+                resource_size_t align1 = 1;
+
+                align1 <<= (order + 20);
+
+                if (!align)
+                        min_align = align1;
+                else if (ALIGN(align + min_align, min_align) < align1)
+                        min_align = align1 >> 1;
+                align += aligns[order];
+        }
+
+        return min_align;
+}
+
 /**
  * pbus_size_mem() - size the memory window of a given bus
  *
@@ -891,20 +913,8 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                                 children_add_size += get_res_add_size(realloc_head, r);
                 }
         }
-        align = 0;
-        min_align = 0;
-        for (order = 0; order <= max_order; order++) {
-                resource_size_t align1 = 1;
-
-                align1 <<= (order + 20);
-
-                if (!align)
-                        min_align = align1;
-                else if (ALIGN(align + min_align, min_align) < align1)
-                        min_align = align1 >> 1;
-                align += aligns[order];
-        }
 
+        min_align = calculate_mem_align(aligns, max_order);
         min_align = max(min_align, window_alignment(bus, b_res->flags & mask));
         size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
         if (children_add_size > add_size)