From 66701b1499a3ff11882c8c4aef36e8eac86e17b1 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Sat, 10 Feb 2007 01:43:09 -0800 Subject: [PATCH] optional ZONE_DMA: introduce CONFIG_ZONE_DMA This patch simply defines CONFIG_ZONE_DMA for all arches. We later do special things with CONFIG_ZONE_DMA after the VM and an arch are prepared to work without ZONE_DMA. CONFIG_ZONE_DMA can be defined in two ways depending on how an architecture handles ISA DMA. First if CONFIG_GENERIC_ISA_DMA is set by the arch then we know that the arch needs ZONE_DMA because ISA DMA devices are supported. We can catch this in mm/Kconfig and do not need to modify arch code. Second, arches may use ZONE_DMA in an unknown way. We set CONFIG_ZONE_DMA for all arches that do not set CONFIG_GENERIC_ISA_DMA in order to insure backwards compatibility. The arches may later undefine ZONE_DMA if their arch code has been verified to not depend on ZONE_DMA. Signed-off-by: Christoph Lameter Cc: Andi Kleen Cc: "Luck, Tony" Cc: Kyle McMartin Cc: Matthew Wilcox Cc: James Bottomley Cc: Paul Mundt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index db7c55de92cd..50f7cfc15b78 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -139,6 +139,10 @@ config SPLIT_PTLOCK_CPUS default "4096" if PARISC && !PA20 default "4" +config ZONE_DMA + def_bool y + depends on GENERIC_ISA_DMA + # # support for page migration # -- cgit v1.2.1