dma-debug: make memory range checks more consistent

Impact: extend on-kernel-stack DMA debug checks to all !highmem pages

We only checked dma_map_single() - extend it to dma_map_page()
and dma_map_sg() as well.

Also, fix dma_map_single() corner case bug: make sure we dont
stack-check highmem (not mapped) pages.

Reported-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
LKML-Reference: <1237818908-26516-1-git-send-email-joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>