linux/arch/sparc64
Christoph Lameter 5ac6da669e [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA
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>
2007-02-11 10:51:19 -08:00
..
boot [SPARC64]: Add .gitignore file for sparc64 boot images. 2006-02-05 00:15:11 -08:00
kernel [SPARC64]: Set g4/g5 properly in sun4v dtlb-prot handling. 2007-01-26 18:56:01 -08:00
lib Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
math-emu [SPARC64] math-emu: Delete debugging printk left by previous commit. 2006-03-20 01:13:53 -08:00
mm [PATCH] Drop free_pages() 2007-02-11 10:51:18 -08:00
oprofile [PATCH] Move Kprobes and Oprofile to "Instrumentation Support" menu 2005-11-07 07:53:35 -08:00
prom [SPARC]: Kill prom_getname, unused and not implemented properly. 2006-07-21 14:17:55 -07:00
solaris [PATCH] struct path: convert sparc64 2006-12-08 08:28:50 -08:00
defconfig [SPARC64]: Update defconfig. 2006-12-31 14:06:06 -08:00
Kconfig [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA 2007-02-11 10:51:19 -08:00
Kconfig.debug [SPARC64]: Add irqtrace/stacktrace/lockdep support. 2006-12-10 02:39:09 -08:00
Makefile [SPARC64]: Stop putting -finline-limit=XXX into CFLAGS 2005-12-20 14:53:05 -08:00