linux/arch/m32r
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 [PATCH] m32r: bootloader support for OPSPUT platform 2006-12-08 08:28:37 -08:00
kernel [PATCH] Change cpu_up and co from __devinit to __cpuinit 2007-01-11 18:18:20 -08:00
lib [NET]: M32R checksum annotations and cleanups. 2006-12-02 21:23:06 -08:00
m32104ut [PATCH] m32r: Support M32104UT target platform 2006-01-06 08:33:43 -08:00
m32700ut [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
mappi [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
mappi2 [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
mappi3 [PATCH] m32r: Support M3A-2170(Mappi-III) platform 2005-06-21 19:07:30 -07:00
mm [PATCH] m32r: fix ace_handler to pass full 32-bit address 2006-12-08 08:28:37 -08:00
oaks32r [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
oprofile Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
opsput [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
defconfig [PATCH] m32r: Update defconfig files 2005-06-21 19:07:31 -07:00
Kconfig [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA 2007-02-11 10:51:19 -08:00
Kconfig.debug [PATCH] kconfig: clarify memory debug options 2006-03-25 08:22:54 -08:00
Makefile Merge master.kernel.org:/pub/scm/linux/kernel/git/sam/kbuild 2006-03-25 08:48:48 -08:00