[PATCH] x86_64: Rename IOMMU option, fix help and mark option embedded.

 - Rename the GART_IOMMU option to IOMMU to make clear it's not
   just for AMD
 - Rewrite the help text to better emphatise this fact
 - Make it an embedded option because too many people get it wrong.

To my astonishment I discovered the aacraid driver tests this
symbol directly. This looks quite broken to me - it's an internal
implementation detail of the PCI DMA API. Can the maintainer
please clarify what this test was intended to do?

Cc: linux-scsi@vger.kernel.org
Cc: alan@redhat.com
Cc: markh@osdl.org
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index 35b0a6e..7cea514 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -104,8 +104,11 @@
 	 * always true on real computers. It also has some slight problems
 	 * with the GART on x86-64. I've btw never tried DMA from PCI space
 	 * on this platform but don't be surprised if its problematic.
+	 * [AK: something is very very wrong when a driver tests this symbol.
+ 	 *  Someone should figure out what the comment writer really meant here and fix
+	 *  the code. Or just remove that bad code. ]
 	 */
-#ifndef CONFIG_GART_IOMMU
+#ifndef CONFIG_IOMMU
 	if ((num_physpages << (PAGE_SHIFT - 12)) <= AAC_MAX_HOSTPHYSMEMPAGES) {
 		init->HostPhysMemPages = 
 			cpu_to_le32(num_physpages << (PAGE_SHIFT-12));