+/* PTBs (Page Table Blocks) need to be aligned to 32K */
+#define RADEON_VM_PTB_ALIGN_SIZE 32768
+#define RADEON_VM_PTB_ALIGN_MASK (RADEON_VM_PTB_ALIGN_SIZE - 1)
+#define RADEON_VM_PTB_ALIGN(a) (((a) + RADEON_VM_PTB_ALIGN_MASK) & ~RADEON_VM_PTB_ALIGN_MASK)
+