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