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authorChristoph Lameter <clameter@sgi.com>2007-02-10 01:43:09 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-11 10:51:18 -0800
commit66701b1499a3ff11882c8c4aef36e8eac86e17b1 (patch)
tree7900ced6b590c3cd939bcdc92355ff0a14f856e3 /mm
parent6267276f3fdda9ad0d5ca451bdcbdf42b802d64b (diff)
downloadop-kernel-dev-66701b1499a3ff11882c8c4aef36e8eac86e17b1.zip
op-kernel-dev-66701b1499a3ff11882c8c4aef36e8eac86e17b1.tar.gz
[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 <clameter@sgi.com> Cc: Andi Kleen <ak@suse.de> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <willy@debian.org> Cc: James Bottomley <James.Bottomley@steeleye.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/Kconfig4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig
index db7c55d..50f7cfc 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
#
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