iommu sg merging: alpha: make pci_iommu respect the segment size limits

This patch makes pci_iommu respect segment size limits when merging sg
lists.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-alpha/pci.h b/include/asm-alpha/pci.h
index 30ee766..d5b10ef 100644
--- a/include/asm-alpha/pci.h
+++ b/include/asm-alpha/pci.h
@@ -4,6 +4,7 @@
 #ifdef __KERNEL__
 
 #include <linux/spinlock.h>
+#include <linux/dma-mapping.h>
 #include <asm/scatterlist.h>
 #include <asm/machvec.h>