From: Christoph Lameter ZONE_DMA depends on GENERIC_ISA_DMA. We allow the user to configure GENERIC_ISA_DMA. If it is switched off then ISA_DMA_API is also switched off which will deselect all drivers that depend on ISA functionality. Signed-off-by: Christoph Lameter Cc: Andi Kleen Signed-off-by: Andrew Morton --- arch/i386/Kconfig | 14 ++++++++++---- arch/i386/kernel/Makefile | 3 ++- arch/i386/kernel/setup.c | 4 ++++ 3 files changed, 16 insertions(+), 5 deletions(-) diff -puN arch/i386/Kconfig~optional-zone_dma-for-i386 arch/i386/Kconfig --- a/arch/i386/Kconfig~optional-zone_dma-for-i386 +++ a/arch/i386/Kconfig @@ -41,10 +41,6 @@ config MMU config SBUS bool -config GENERIC_ISA_DMA - bool - default y - config GENERIC_IOMAP bool default y @@ -346,6 +342,15 @@ config VM86 XFree86 to initialize some video cards via BIOS. Disabling this option saves about 6k. +config GENERIC_ISA_DMA + bool "ISA DMA zone (to support ISA legacy DMA)" + default y + help + If DMA for ISA boards needs to be supported then this option + needs to be enabled. An additional DMA zone for <16MB memory + will be created and memory below 16MB will be used for those + devices. + config TOSHIBA tristate "Toshiba Laptop support" ---help--- @@ -1051,6 +1056,7 @@ source "drivers/pci/Kconfig" config ISA_DMA_API bool + depends on GENERIC_ISA_DMA default y config ISA diff -puN arch/i386/kernel/Makefile~optional-zone_dma-for-i386 arch/i386/kernel/Makefile --- a/arch/i386/kernel/Makefile~optional-zone_dma-for-i386 +++ a/arch/i386/kernel/Makefile @@ -7,8 +7,9 @@ extra-y := head.o init_task.o vmlinux.ld obj-y := process.o signal.o entry.o traps.o irq.o \ ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \ pci-dma.o i386_ksyms.o i387.o bootflag.o \ - quirks.o i8237.o topology.o alternative.o i8253.o tsc.o + quirks.o topology.o alternative.o i8253.o tsc.o +obj-$(CONFIG_GENERIC_ISA_DMA) += i8237.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-y += cpu/ obj-y += acpi/ diff -puN arch/i386/kernel/setup.c~optional-zone_dma-for-i386 arch/i386/kernel/setup.c --- a/arch/i386/kernel/setup.c~optional-zone_dma-for-i386 +++ a/arch/i386/kernel/setup.c @@ -1041,13 +1041,17 @@ void __init zone_sizes_init(void) { #ifdef CONFIG_HIGHMEM unsigned long max_zone_pfns[MAX_NR_ZONES] = { +#ifdef CONFIG_ZONE_DMA virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT, +#endif max_low_pfn, highend_pfn}; add_active_range(0, 0, highend_pfn); #else unsigned long max_zone_pfns[MAX_NR_ZONES] = { +#ifdef CONFIG_ZONE_DMA virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT, +#endif max_low_pfn}; add_active_range(0, 0, max_low_pfn); #endif _