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Diffstat (limited to '')
| -rw-r--r-- | kernel/dma/Kconfig | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig new file mode 100644 index 000000000..56866aaa2 --- /dev/null +++ b/kernel/dma/Kconfig @@ -0,0 +1,244 @@ +# 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_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 thing 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 + +config SWIOTLB + bool + select NEED_DMA_MAP_STATE + +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_PERNUMA_CMA + bool "Enable separate DMA Contiguous Memory Area for each NUMA Node" + default NUMA && ARM64 + help + Enable this option to get pernuma CMA areas so that devices like + ARM64 SMMU can get local memory by DMA coherent APIs. + + You can set the size of pernuma CMA by specifying "cma_pernuma=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 |