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As Andi pointed out: CONFIG_GENERIC_ISA_DMA only disables the ISA DMA channel management. Other functionality may still expect GFP_DMA to provide memory below 16M. So we need to make sure that CONFIG_ZONE_DMA is set independent of CONFIG_GENERIC_ISA_DMA. Undo the modifications to mm/Kconfig where we made ZONE_DMA dependent on GENERIC_ISA_DMA and set theses explicitly in each arches Kconfig. Reviews must occur for each arch in order to determine if ZONE_DMA can be switched off. It can only be switched off if we know that all devices supported by a platform are capable of performing DMA transfers to all of memory (Some arches already support this: uml, avr32, sh sh64, parisc and IA64/Altix). In order to switch ZONE_DMA off conditionally, one would have to establish a scheme by which one can assure that no drivers are enabled that are only capable of doing I/O to a part of memory, or one needs to provide an alternate means of performing an allocation from a specific range of memory (like provided by alloc_pages_range()) and insure that all drivers use that call. In that case the arches alloc_dma_coherent() may need to be modified to call alloc_pages_range() instead of relying on GFP_DMA. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
boot | ||
common | ||
configs | ||
kernel | ||
lib | ||
mach-aaec2000 | ||
mach-at91rm9200 | ||
mach-clps711x | ||
mach-clps7500 | ||
mach-ebsa110 | ||
mach-ep93xx | ||
mach-footbridge | ||
mach-h720x | ||
mach-imx | ||
mach-integrator | ||
mach-iop13xx | ||
mach-iop32x | ||
mach-iop33x | ||
mach-ixp4xx | ||
mach-ixp23xx | ||
mach-ixp2000 | ||
mach-l7200 | ||
mach-lh7a40x | ||
mach-netx | ||
mach-omap1 | ||
mach-omap2 | ||
mach-pnx4008 | ||
mach-pxa | ||
mach-realview | ||
mach-rpc | ||
mach-s3c2410 | ||
mach-sa1100 | ||
mach-shark | ||
mach-versatile | ||
mm | ||
nwfpe | ||
oprofile | ||
plat-iop | ||
plat-omap | ||
tools | ||
vfp | ||
Kconfig | ||
Kconfig-nommu | ||
Kconfig.debug | ||
Makefile |