x86_64: optional ZONE_DMA/ZONE_DMA32 Allow the use to specify CONFIG_ZONE_DMA32 and CONFIG_ZONE_DMA (via CONFIG_GENERIC_ISA_DMA). If CONFIG_ZONE_DMA is off then devices requiring ISA DMA can no longer be selected. There are no drivers depending on CONFIG_ZONE_DMA32. If CONFIG_ZONE_DMA32 is not set then the system assumes that DMA devices are capable of doing DMA to all of memory (which is mostly the case since most x86_64 motherboards only allow a max of 4GB of memory and advanced systems have DMA subsystems that handle I/O properly). Signed-off-by: Christoph Lameter <clameter@xxxxxxx> Index: linux-2.6.18-rc6-mm1/arch/x86_64/mm/init.c =================================================================== --- linux-2.6.18-rc6-mm1.orig/arch/x86_64/mm/init.c 2006-09-11 16:06:41.705747849 -0500 +++ linux-2.6.18-rc6-mm1/arch/x86_64/mm/init.c 2006-09-11 16:08:13.190088058 -0500 @@ -406,9 +406,15 @@ #ifndef CONFIG_NUMA void __init paging_init(void) { - unsigned long max_zone_pfns[MAX_NR_ZONES] = {MAX_DMA_PFN, - MAX_DMA32_PFN, - end_pfn}; + unsigned long max_zone_pfns[MAX_NR_ZONES] = { +#ifdef CONFIG_ZONE_DMA + MAX_DMA_PFN, +#endif +#ifdef CONFIG_ZONE_DMA32 + MAX_DMA32_PFN, +#endif + end_pfn + }; memory_present(0, 0, end_pfn); sparse_init(); free_area_init_nodes(max_zone_pfns); Index: linux-2.6.18-rc6-mm1/arch/x86_64/Kconfig =================================================================== --- linux-2.6.18-rc6-mm1.orig/arch/x86_64/Kconfig 2006-09-11 16:06:41.713561013 -0500 +++ linux-2.6.18-rc6-mm1/arch/x86_64/Kconfig 2006-09-11 16:10:45.369039566 -0500 @@ -24,10 +24,6 @@ bool default y -config ZONE_DMA32 - bool - default y - config LOCKDEP_SUPPORT bool default y @@ -73,10 +69,6 @@ bool default y -config GENERIC_ISA_DMA - bool - default y - config GENERIC_IOMAP bool default y @@ -251,6 +243,24 @@ See <file:Documentation/mtrr.txt> for more information. +config ZONE_DMA32 + bool "32 Bit DMA Zone (only needed if memory >4GB)" + default y + help + Some x64 configurations have 32 bit DMA controllers that cannot + write to all of memory. If you have one of these and you have RAM + beyond the 4GB boundary then enable this option. + +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. If this is deselected then devices that use ISA + DMA will not be selectable. + config SMP bool "Symmetric multi-processing support" ---help--- @@ -611,6 +621,7 @@ # we have no ISA slots, but we do have ISA-style DMA. config ISA_DMA_API bool + depends on GENERIC_ISA_DMA default y config GENERIC_PENDING_IRQ Index: linux-2.6.18-rc6-mm1/arch/x86_64/kernel/Makefile =================================================================== --- linux-2.6.18-rc6-mm1.orig/arch/x86_64/kernel/Makefile 2006-09-11 16:06:41.726257405 -0500 +++ linux-2.6.18-rc6-mm1/arch/x86_64/kernel/Makefile 2006-09-11 16:08:13.214504197 -0500 @@ -7,9 +7,10 @@ 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_x86_64.o \ x8664_ksyms.o i387.o syscall.o vsyscall.o \ - setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \ + setup64.o bootflag.o e820.o reboot.o quirks.o \ pci-dma.o pci-nommu.o alternative.o early-quirks.o +obj-$(CONFIG_GENERIC_ISA_DMA) += i8237.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_X86_MCE) += mce.o obj-$(CONFIG_X86_MCE_INTEL) += mce_intel.o - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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