1# SPDX-License-Identifier: GPL-2.0-only 2 3config NO_DMA 4 bool 5 6config HAS_DMA 7 bool 8 depends on !NO_DMA 9 default y 10 11config DMA_OPS 12 depends on HAS_DMA 13 bool 14 15# 16# IOMMU drivers that can bypass the IOMMU code and optionally use the direct 17# mapping fast path should select this option and set the dma_ops_bypass 18# flag in struct device where applicable 19# 20config DMA_OPS_BYPASS 21 bool 22 23config NEED_SG_DMA_LENGTH 24 bool 25 26config NEED_DMA_MAP_STATE 27 bool 28 29config ARCH_DMA_ADDR_T_64BIT 30 def_bool 64BIT || PHYS_ADDR_T_64BIT 31 32config ARCH_HAS_DMA_COHERENCE_H 33 bool 34 35config ARCH_HAS_DMA_SET_MASK 36 bool 37 38# 39# Select this option if the architecture needs special handling for 40# DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what 41# people thing of when saying write combine, so very few platforms should 42# need to enable this. 43# 44config ARCH_HAS_DMA_WRITE_COMBINE 45 bool 46 47# 48# Select if the architectures provides the arch_dma_mark_clean hook 49# 50config ARCH_HAS_DMA_MARK_CLEAN 51 bool 52 53config DMA_DECLARE_COHERENT 54 bool 55 56config ARCH_HAS_SETUP_DMA_OPS 57 bool 58 59config ARCH_HAS_TEARDOWN_DMA_OPS 60 bool 61 62config ARCH_HAS_SYNC_DMA_FOR_DEVICE 63 bool 64 65config ARCH_HAS_SYNC_DMA_FOR_CPU 66 bool 67 select NEED_DMA_MAP_STATE 68 69config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL 70 bool 71 72config ARCH_HAS_DMA_PREP_COHERENT 73 bool 74 75config ARCH_HAS_FORCE_DMA_UNENCRYPTED 76 bool 77 78config SWIOTLB 79 bool 80 select NEED_DMA_MAP_STATE 81 82# 83# Should be selected if we can mmap non-coherent mappings to userspace. 84# The only thing that is really required is a way to set an uncached bit 85# in the pagetables 86# 87config DMA_NONCOHERENT_MMAP 88 default y if !MMU 89 bool 90 91config DMA_COHERENT_POOL 92 select GENERIC_ALLOCATOR 93 bool 94 95config DMA_REMAP 96 bool 97 depends on MMU 98 select DMA_NONCOHERENT_MMAP 99 100config DMA_DIRECT_REMAP 101 bool 102 select DMA_REMAP 103 select DMA_COHERENT_POOL 104 105config DMA_CMA 106 bool "DMA Contiguous Memory Allocator" 107 depends on HAVE_DMA_CONTIGUOUS && CMA 108 help 109 This enables the Contiguous Memory Allocator which allows drivers 110 to allocate big physically-contiguous blocks of memory for use with 111 hardware components that do not support I/O map nor scatter-gather. 112 113 You can disable CMA by specifying "cma=0" on the kernel's command 114 line. 115 116 For more information see <kernel/dma/contiguous.c>. 117 If unsure, say "n". 118 119if DMA_CMA 120 121config DMA_PERNUMA_CMA 122 bool "Enable separate DMA Contiguous Memory Area for each NUMA Node" 123 default NUMA && ARM64 124 help 125 Enable this option to get pernuma CMA areas so that devices like 126 ARM64 SMMU can get local memory by DMA coherent APIs. 127 128 You can set the size of pernuma CMA by specifying "cma_pernuma=size" 129 on the kernel's command line. 130 131comment "Default contiguous memory area size:" 132 133config CMA_SIZE_MBYTES 134 int "Size in Mega Bytes" 135 depends on !CMA_SIZE_SEL_PERCENTAGE 136 default 0 if X86 137 default 16 138 help 139 Defines the size (in MiB) of the default memory area for Contiguous 140 Memory Allocator. If the size of 0 is selected, CMA is disabled by 141 default, but it can be enabled by passing cma=size[MG] to the kernel. 142 143 144config CMA_SIZE_PERCENTAGE 145 int "Percentage of total memory" 146 depends on !CMA_SIZE_SEL_MBYTES 147 default 0 if X86 148 default 10 149 help 150 Defines the size of the default memory area for Contiguous Memory 151 Allocator as a percentage of the total memory in the system. 152 If 0 percent is selected, CMA is disabled by default, but it can be 153 enabled by passing cma=size[MG] to the kernel. 154 155choice 156 prompt "Selected region size" 157 default CMA_SIZE_SEL_MBYTES 158 159config CMA_SIZE_SEL_MBYTES 160 bool "Use mega bytes value only" 161 162config CMA_SIZE_SEL_PERCENTAGE 163 bool "Use percentage value only" 164 165config CMA_SIZE_SEL_MIN 166 bool "Use lower value (minimum)" 167 168config CMA_SIZE_SEL_MAX 169 bool "Use higher value (maximum)" 170 171endchoice 172 173config CMA_ALIGNMENT 174 int "Maximum PAGE_SIZE order of alignment for contiguous buffers" 175 range 2 12 176 default 8 177 help 178 DMA mapping framework by default aligns all buffers to the smallest 179 PAGE_SIZE order which is greater than or equal to the requested buffer 180 size. This works well for buffers up to a few hundreds kilobytes, but 181 for larger buffers it just a memory waste. With this parameter you can 182 specify the maximum PAGE_SIZE order for contiguous buffers. Larger 183 buffers will be aligned only to this specified order. The order is 184 expressed as a power of two multiplied by the PAGE_SIZE. 185 186 For example, if your system defaults to 4KiB pages, the order value 187 of 8 means that the buffers will be aligned up to 1MiB only. 188 189 If unsure, leave the default value "8". 190 191endif 192 193config DMA_API_DEBUG 194 bool "Enable debugging of DMA-API usage" 195 select NEED_DMA_MAP_STATE 196 help 197 Enable this option to debug the use of the DMA API by device drivers. 198 With this option you will be able to detect common bugs in device 199 drivers like double-freeing of DMA mappings or freeing mappings that 200 were never allocated. 201 202 This option causes a performance degradation. Use only if you want to 203 debug device drivers and dma interactions. 204 205 If unsure, say N. 206 207config DMA_API_DEBUG_SG 208 bool "Debug DMA scatter-gather usage" 209 default y 210 depends on DMA_API_DEBUG 211 help 212 Perform extra checking that callers of dma_map_sg() have respected the 213 appropriate segment length/boundary limits for the given device when 214 preparing DMA scatterlists. 215 216 This is particularly likely to have been overlooked in cases where the 217 dma_map_sg() API is used for general bulk mapping of pages rather than 218 preparing literal scatter-gather descriptors, where there is a risk of 219 unexpected behaviour from DMA API implementations if the scatterlist 220 is technically out-of-spec. 221 222 If unsure, say N. 223