2.6.25-rc7

 lib

diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
new file mode 100644
index 0000000..a3b8d4c
--- /dev/null
+++ b/lib/iommu-helper.c
@@ -0,0 +1,82 @@
+/*
+ * IOMMU helper functions for the free area management
+ */
+
+#include <linux/module.h>
+#include <linux/bitops.h>
+
+static unsigned long find_next_zero_area(unsigned long *map,
+                unsigned long size,
+                unsigned long start,
+                unsigned int nr,
+                unsigned long align_mask)
+{
+   unsigned long index, end, i;
+again:
+   index = find_next_zero_bit(map, size, start);
+
+   /* Align allocation */
+   index = (index + align_mask) & ~align_mask;
+
+   end = index + nr;
+   if (end >= size)
+      return -1;
+   for (i = index; i < end; i++) {
+      if (test_bit(i, map)) {
+         start = i+1;
+         goto again;
+      }
+   }
+   return index;
+}
+
+static inline void set_bit_area(unsigned long *map, unsigned long i,
+            int len)
+{
+   unsigned long end = i + len;
+   while (i < end) {
+      __set_bit(i, map);
+      i++;
+   }
+}
+
+int iommu_is_span_boundary(unsigned int index, unsigned int nr,
+            unsigned long shift,
+            unsigned long boundary_size)
+{
+   BUG_ON(!is_power_of_2(boundary_size));
+
+   shift = (shift + index) & (boundary_size - 1);
+   return shift + nr > boundary_size;
+}
+
+unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
+                unsigned long start, unsigned int nr,
+                unsigned long shift, unsigned long boundary_size,
+                unsigned long align_mask)
+{
+   unsigned long index;
+again:
+   index = find_next_zero_area(map, size, start, nr, align_mask);
+   if (index != -1) {
+      if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
+         /* we could do more effectively */
+         start = index + 1;
+         goto again;
+      }
+      set_bit_area(map, index, nr);
+   }
+   return index;
+}
+EXPORT_SYMBOL(iommu_area_alloc);
+
+void iommu_area_free(unsigned long *map, unsigned long start, unsigned int nr)
+{
+   unsigned long end = start + nr;
+
+   while (start < end) {
+      __clear_bit(start, map);
+      start++;
+   }
+}
+EXPORT_SYMBOL(iommu_area_free);