zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/lib/iommu-helper.c b/ap/os/linux/linux-3.4.x/lib/iommu-helper.c
new file mode 100644
index 0000000..c27e269
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/lib/iommu-helper.c
@@ -0,0 +1,41 @@
+/*
+ * IOMMU helper functions for the free area management
+ */
+
+#include <linux/export.h>
+#include <linux/bitmap.h>
+#include <linux/bug.h>
+
+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;
+
+ /* We don't want the last of the limit */
+ size -= 1;
+again:
+ index = bitmap_find_next_zero_area(map, size, start, nr, align_mask);
+ if (index < size) {
+ if (iommu_is_span_boundary(index, nr, shift, boundary_size)) {
+ /* we could do more effectively */
+ start = index + 1;
+ goto again;
+ }
+ bitmap_set(map, index, nr);
+ return index;
+ }
+ return -1;
+}
+EXPORT_SYMBOL(iommu_area_alloc);