# SPDX-License-Identifier: GPL-2.0-only config NO_DMA	bool config HAS_DMA	bool	depends on !NO_DMA	default y config DMA_OPS	bool ## IOMMU drivers that can bypass the IOMMU code and optionally use the direct# mapping fast path should select this option and set the dma_ops_bypass# flag in struct device where applicable#config DMA_OPS_BYPASS	bool config NEED_SG_DMA_LENGTH	bool config NEED_DMA_MAP_STATE	bool config ARCH_DMA_ADDR_T_64BIT	def_bool 64BIT || PHYS_ADDR_T_64BIT config ARCH_HAS_DMA_COHERENCE_H	bool config ARCH_HAS_DMA_SET_MASK	bool ## Select this option if the architecture needs special handling for# DMA_ATTR_WRITE_COMBINE.  Normally the "uncached" mapping should be what# people thing of when saying write combine, so very few platforms should# need to enable this.#config ARCH_HAS_DMA_WRITE_COMBINE	bool config DMA_DECLARE_COHERENT	bool config ARCH_HAS_SETUP_DMA_OPS	bool config ARCH_HAS_TEARDOWN_DMA_OPS	bool config ARCH_HAS_SYNC_DMA_FOR_DEVICE	bool config ARCH_HAS_SYNC_DMA_FOR_CPU	bool	select NEED_DMA_MAP_STATE config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL	bool config ARCH_HAS_DMA_PREP_COHERENT	bool config ARCH_HAS_FORCE_DMA_UNENCRYPTED	bool config DMA_NONCOHERENT_CACHE_SYNC	bool config DMA_VIRT_OPS	bool	depends on HAS_DMA	select DMA_OPS config SWIOTLB	bool	select NEED_DMA_MAP_STATE ## Should be selected if we can mmap non-coherent mappings to userspace.# The only thing that is really required is a way to set an uncached bit# in the pagetables#config DMA_NONCOHERENT_MMAP	default y if !MMU	bool config DMA_COHERENT_POOL	select GENERIC_ALLOCATOR	bool config DMA_REMAP	bool	depends on MMU	select DMA_NONCOHERENT_MMAP config DMA_DIRECT_REMAP	bool	select DMA_REMAP	select DMA_COHERENT_POOL config DMA_CMA	bool "DMA Contiguous Memory Allocator"	depends on HAVE_DMA_CONTIGUOUS && CMA	help	  This enables the Contiguous Memory Allocator which allows drivers	  to allocate big physically-contiguous blocks of memory for use with	  hardware components that do not support I/O map nor scatter-gather. 	  You can disable CMA by specifying "cma=0" on the kernel's command	  line. 	  For more information see <include/linux/dma-contiguous.h>.	  If unsure, say "n". if  DMA_CMAcomment "Default contiguous memory area size:" config CMA_SIZE_MBYTES	int "Size in Mega Bytes"	depends on !CMA_SIZE_SEL_PERCENTAGE	default 0 if X86	default 16	help	  Defines the size (in MiB) of the default memory area for Contiguous	  Memory Allocator.  If the size of 0 is selected, CMA is disabled by	  default, but it can be enabled by passing cma=size[MG] to the kernel.  config CMA_SIZE_PERCENTAGE	int "Percentage of total memory"	depends on !CMA_SIZE_SEL_MBYTES	default 0 if X86	default 10	help	  Defines the size of the default memory area for Contiguous Memory	  Allocator as a percentage of the total memory in the system.	  If 0 percent is selected, CMA is disabled by default, but it can be	  enabled by passing cma=size[MG] to the kernel. choice	prompt "Selected region size"	default CMA_SIZE_SEL_MBYTES config CMA_SIZE_SEL_MBYTES	bool "Use mega bytes value only" config CMA_SIZE_SEL_PERCENTAGE	bool "Use percentage value only" config CMA_SIZE_SEL_MIN	bool "Use lower value (minimum)" config CMA_SIZE_SEL_MAX	bool "Use higher value (maximum)" endchoice config CMA_ALIGNMENT	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"	range 4 12	default 8	help	  DMA mapping framework by default aligns all buffers to the smallest	  PAGE_SIZE order which is greater than or equal to the requested buffer	  size. This works well for buffers up to a few hundreds kilobytes, but	  for larger buffers it just a memory waste. With this parameter you can	  specify the maximum PAGE_SIZE order for contiguous buffers. Larger	  buffers will be aligned only to this specified order. The order is	  expressed as a power of two multiplied by the PAGE_SIZE. 	  For example, if your system defaults to 4KiB pages, the order value	  of 8 means that the buffers will be aligned up to 1MiB only. 	  If unsure, leave the default value "8". endif config DMA_API_DEBUG	bool "Enable debugging of DMA-API usage"	select NEED_DMA_MAP_STATE	help	  Enable this option to debug the use of the DMA API by device drivers.	  With this option you will be able to detect common bugs in device	  drivers like double-freeing of DMA mappings or freeing mappings that	  were never allocated. 	  This option causes a performance degradation.  Use only if you want to	  debug device drivers and dma interactions. 	  If unsure, say N. config DMA_API_DEBUG_SG	bool "Debug DMA scatter-gather usage"	default y	depends on DMA_API_DEBUG	help	  Perform extra checking that callers of dma_map_sg() have respected the	  appropriate segment length/boundary limits for the given device when	  preparing DMA scatterlists. 	  This is particularly likely to have been overlooked in cases where the	  dma_map_sg() API is used for general bulk mapping of pages rather than	  preparing literal scatter-gather descriptors, where there is a risk of	  unexpected behaviour from DMA API implementations if the scatterlist	  is technically out-of-spec. 	  If unsure, say N.