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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | # SPDX-License-Identifier: GPL-2.0-only config HAS_DMA bool depends on !NO_DMA default y 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 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_DMA_COHERENT_TO_PFN bool config ARCH_HAS_DMA_MMAP_PGPROT bool config ARCH_HAS_FORCE_DMA_UNENCRYPTED bool config DMA_NONCOHERENT_CACHE_SYNC bool config DMA_VIRT_OPS bool depends on HAS_DMA config SWIOTLB bool select NEED_DMA_MAP_STATE config DMA_REMAP depends on MMU select GENERIC_ALLOCATOR bool config DMA_DIRECT_REMAP bool select DMA_REMAP 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_CMA 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 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 also attempts to catch cases where a page owned by DMA is accessed by the cpu in a way that could cause data corruption. For example, this enables cow_user_page() to check that the source page is not undergoing DMA. 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. |