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+# SPDX-License-Identifier: GPL-2.0-only
+
+config NO_DMA
+ bool
+
+config HAS_DMA
+ bool
+ depends on !NO_DMA
+ default y
+
+config DMA_OPS
+ depends on HAS_DMA
+ 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
+
+# Lets platform IOMMU driver choose between bypass and IOMMU
+config ARCH_HAS_DMA_MAP_DIRECT
+ bool
+
+config NEED_SG_DMA_FLAGS
+ 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_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 think of when saying write combine, so very few platforms should
+# need to enable this.
+#
+config ARCH_HAS_DMA_WRITE_COMBINE
+ bool
+
+#
+# Select if the architectures provides the arch_dma_mark_clean hook
+#
+config ARCH_HAS_DMA_MARK_CLEAN
+ 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
+
+#
+# Select this option if the architecture assumes DMA devices are coherent
+# by default.
+#
+config ARCH_DMA_DEFAULT_COHERENT
+ bool
+
+config SWIOTLB
+ bool
+ select NEED_DMA_MAP_STATE
+
+config SWIOTLB_DYNAMIC
+ bool "Dynamic allocation of DMA bounce buffers"
+ default n
+ depends on SWIOTLB
+ help
+ This enables dynamic resizing of the software IO TLB. The kernel
+ starts with one memory pool at boot and it will allocate additional
+ pools as needed. To reduce run-time kernel memory requirements, you
+ may have to specify a smaller size of the initial pool using
+ "swiotlb=" on the kernel command line.
+
+ If unsure, say N.
+
+config DMA_BOUNCE_UNALIGNED_KMALLOC
+ bool
+ depends on SWIOTLB
+
+config DMA_RESTRICTED_POOL
+ bool "DMA Restricted Pool"
+ depends on OF && OF_RESERVED_MEM && SWIOTLB
+ help
+ This enables support for restricted DMA pools which provide a level of
+ DMA memory protection on systems with limited hardware protection
+ capabilities, such as those lacking an IOMMU.
+
+ For more information see
+ <Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt>
+ and <kernel/dma/swiotlb.c>.
+ If unsure, say "n".
+
+#
+# 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_GLOBAL_POOL
+ select DMA_DECLARE_COHERENT
+ bool
+
+config DMA_DIRECT_REMAP
+ bool
+ select DMA_COHERENT_POOL
+ select DMA_NONCOHERENT_MMAP
+
+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 <kernel/dma/contiguous.c>.
+ If unsure, say "n".
+
+if DMA_CMA
+
+config DMA_NUMA_CMA
+ bool "Enable separate DMA Contiguous Memory Area for NUMA Node"
+ depends on NUMA
+ help
+ Enable this option to get numa CMA areas so that NUMA devices
+ can get local memory by DMA coherent APIs.
+
+ You can set the size of pernuma CMA by specifying "cma_pernuma=size"
+ or set the node id and its size of CMA by specifying "numa_cma=
+ <node>:size[,<node>:size]" on the kernel's command line.
+
+comment "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 2 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.
+
+config DMA_MAP_BENCHMARK
+ bool "Enable benchmarking of streaming DMA mapping"
+ depends on DEBUG_FS
+ help
+ Provides /sys/kernel/debug/dma_map_benchmark that helps with testing
+ performance of dma_(un)map_page.
+
+ See tools/testing/selftests/dma/dma_map_benchmark.c