[IA64] swiotlb bug fixes

This patch fixes
- marking I-cache clean of pages DMAed to now only done for IA64
- broken multiple inclusion in include/asm-x86_64/swiotlb.h
- missing call to mark_clean in swiotlb_sync_sg()
- a (perhaps only theoretical) issue in swiotlb_dma_supported() when
io_tlb_end is exactly at the end of memory

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/dma.h b/include/asm-ia64/dma.h
index dad3a73..4d97f60 100644
--- a/include/asm-ia64/dma.h
+++ b/include/asm-ia64/dma.h
@@ -19,4 +19,6 @@
 
 #define free_dma(x)
 
+void dma_mark_clean(void *addr, size_t size);
+
 #endif /* _ASM_IA64_DMA_H */