From: Christoph Lameter 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 Signed-off-by: Andrew Morton --- arch/alpha/Kconfig | 4 ++++ arch/arm/Kconfig | 4 ++++ arch/arm26/Kconfig | 4 ++++ arch/i386/Kconfig | 4 ++++ arch/m32r/Kconfig | 4 ++++ arch/m68k/Kconfig | 4 ++++ arch/mips/Kconfig | 4 ++++ arch/powerpc/Kconfig | 4 ++++ arch/ppc/Kconfig | 4 ++++ arch/sparc/Kconfig | 4 ++++ arch/sparc64/Kconfig | 4 ++++ arch/x86_64/Kconfig | 4 ++++ mm/Kconfig | 4 ---- 13 files changed, 48 insertions(+), 4 deletions(-) diff -puN arch/alpha/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/alpha/Kconfig --- a/arch/alpha/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/alpha/Kconfig @@ -33,6 +33,10 @@ config GENERIC_CALIBRATE_DELAY bool default y +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool default y diff -puN arch/arm/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/arm/Kconfig --- a/arch/arm/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/arm/Kconfig @@ -88,6 +88,10 @@ config GENERIC_BUST_SPINLOCK config ARCH_MAY_HAVE_PC_FDC bool +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool diff -puN arch/arm26/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/arm26/Kconfig --- a/arch/arm26/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/arm26/Kconfig @@ -52,6 +52,10 @@ config GENERIC_CALIBRATE_DELAY config GENERIC_BUST_SPINLOCK bool +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool diff -puN arch/i386/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/i386/Kconfig --- a/arch/i386/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/i386/Kconfig @@ -38,6 +38,10 @@ config MMU bool default y +config ZONE_DMA + bool + default y + config SBUS bool diff -puN arch/m32r/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/m32r/Kconfig --- a/arch/m32r/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/m32r/Kconfig @@ -16,6 +16,10 @@ config GENERIC_ISA_DMA bool default y +config ZONE_DMA + bool + default y + config GENERIC_HARDIRQS bool default y diff -puN arch/m68k/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/m68k/Kconfig --- a/arch/m68k/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/m68k/Kconfig @@ -431,6 +431,10 @@ config GENERIC_ISA_DMA depends on Q40 || AMIGA_PCMCIA || GG2 default y +config ZONE_DMA + bool + default y + source "drivers/pci/Kconfig" source "drivers/zorro/Kconfig" diff -puN arch/mips/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/mips/Kconfig --- a/arch/mips/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/mips/Kconfig @@ -8,6 +8,10 @@ mainmenu "Linux/MIPS Kernel Configuratio menu "Machine selection" +config ZONE_DMA + bool + default y + choice prompt "System type" default SGI_IP22 diff -puN arch/powerpc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/powerpc/Kconfig --- a/arch/powerpc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/powerpc/Kconfig @@ -836,6 +836,10 @@ config ISA have an IBM RS/6000 or pSeries machine or a PReP machine, say Y. If you have an embedded board, consult your board documentation. +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool depends on PPC64 || POWER4 || 6xx && !CPM2 diff -puN arch/ppc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/ppc/Kconfig --- a/arch/ppc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/ppc/Kconfig @@ -1162,6 +1162,10 @@ config ISA have an IBM RS/6000 or pSeries machine or a PReP machine, say Y. If you have an embedded board, consult your board documentation. +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool depends on 6xx && !CPM2 diff -puN arch/sparc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/sparc/Kconfig --- a/arch/sparc/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/sparc/Kconfig @@ -13,6 +13,10 @@ config HIGHMEM bool default y +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool default y diff -puN arch/sparc64/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/sparc64/Kconfig --- a/arch/sparc64/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/sparc64/Kconfig @@ -216,6 +216,10 @@ config LARGE_ALLOCS source "mm/Kconfig" +config ZONE_DMA + bool + default y + config GENERIC_ISA_DMA bool default y diff -puN arch/x86_64/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma arch/x86_64/Kconfig --- a/arch/x86_64/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/arch/x86_64/Kconfig @@ -44,6 +44,10 @@ config MMU bool default y +config ZONE_DMA + bool + default y + config ISA bool diff -puN mm/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma mm/Kconfig --- a/mm/Kconfig~set-config_zone_dma-for-arches-with-generic_isa_dma +++ a/mm/Kconfig @@ -139,10 +139,6 @@ 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 # _