WSL2-Linux-Kernel/arch/ppc
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
..
4xx_io [POWERPC] ARCH=ppc pt_regs fixes 2006-10-10 11:55:25 +10:00
8xx_io [POWERPC] ppc: cs4218_tdm remove extra brace 2007-02-08 15:29:22 +11:00
8260_io [PATCH] getting rid of all casts of k[cmz]alloc() calls 2006-12-13 09:05:58 -08:00
amiga Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
boot [POWERPC] Remove the broken Gemini support 2007-01-24 21:13:58 +11:00
configs [POWERPC] Remove the broken Gemini support 2007-01-24 21:13:58 +11:00
kernel [POWERPC] Compile fixes for arch/powerpc dcr code 2007-02-07 14:03:23 +11:00
lib [POWERPC] PPC: Use ARRAY_SIZE macro when appropriate 2007-02-08 16:08:25 +11:00
mm [POWERPC] Add "is_power_of_2" checking to log2.h. 2007-02-07 14:03:19 +11:00
platforms [POWERPC] Fix apparent typo "CONFIG_SERIAL_CPM_SMC". 2007-02-07 14:03:17 +11:00
syslib [POWERPC] PPC: Use ARRAY_SIZE macro when appropriate 2007-02-08 16:08:25 +11:00
xmon [POWERPC] PPC: Use ARRAY_SIZE macro when appropriate 2007-02-08 16:08:25 +11:00
.gitignore [POWERPC] Add files build to .gitignore 2006-12-04 20:41:29 +11:00
Kconfig [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA 2007-02-11 10:51:19 -08:00
Kconfig.debug ppc: Remove CHRP, POWER3 and POWER4 support from arch/ppc 2006-03-28 10:22:10 +11:00
Makefile Merge branch '85xx' of git://git.kernel.org/pub/scm/linux/kernel/git/galak/powerpc 2006-03-28 17:03:19 +11:00