[linux-2.6-block.git] / kernel / dma / Kconfig

# 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 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.
Commit	Line	Data
ec8f24b7	1	# SPDX-License-Identifier: GPL-2.0-only
cf65a0f6 CH	2
	3	config HAS_DMA
	4	bool
	5	depends on !NO_DMA
	6	default y
	7
	8	config NEED_SG_DMA_LENGTH
	9	bool
	10
	11	config NEED_DMA_MAP_STATE
	12	bool
	13
	14	config ARCH_DMA_ADDR_T_64BIT
	15	def_bool 64BIT \|\| PHYS_ADDR_T_64BIT
	16
f3ecc0ff CH	17	config ARCH_HAS_DMA_COHERENCE_H
	18	bool
	19
11ddce15 CH	20	config ARCH_HAS_DMA_SET_MASK
	21	bool
	22
ff4c25f2	23	config DMA_DECLARE_COHERENT
cf65a0f6 CH	24	bool
cf65a0f6 CH	25
347cb6af CH	26	config ARCH_HAS_SETUP_DMA_OPS
	27	bool
	28
dc2acded	29	config ARCH_HAS_TEARDOWN_DMA_OPS
cf65a0f6 CH	30	bool
	31
	32	config ARCH_HAS_SYNC_DMA_FOR_DEVICE
	33	bool
	34
	35	config ARCH_HAS_SYNC_DMA_FOR_CPU
	36	bool
	37	select NEED_DMA_MAP_STATE
	38
684f7e91 CH	39	config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
	40	bool
	41
13bf5ced CH	42	config ARCH_HAS_DMA_PREP_COHERENT
	43	bool
	44
58b04406	45	config ARCH_HAS_DMA_COHERENT_TO_PFN
cf65a0f6	46	bool
cf65a0f6	47
58b04406	48	config ARCH_HAS_DMA_MMAP_PGPROT
cf65a0f6	49	bool
58b04406	50
cf65a0f6 CH	51	config DMA_NONCOHERENT_CACHE_SYNC
cf65a0f6 CH	52	bool
cf65a0f6 CH	53
	54	config DMA_VIRT_OPS
	55	bool
	56	depends on HAS_DMA
	57
	58	config SWIOTLB
	59	bool
cf65a0f6	60	select NEED_DMA_MAP_STATE
f0edfea8 CH	61
	62	config DMA_REMAP
	63	depends on MMU
c13edf81	64	select GENERIC_ALLOCATOR
f0edfea8	65	bool
0c3b3171 CH	66
	67	config DMA_DIRECT_REMAP
	68	bool
0c3b3171	69	select DMA_REMAP
70ca7ba2	70
ddb26d8e CH	71	config DMA_CMA
	72	bool "DMA Contiguous Memory Allocator"
	73	depends on HAVE_DMA_CONTIGUOUS && CMA
	74	help
	75	This enables the Contiguous Memory Allocator which allows drivers
	76	to allocate big physically-contiguous blocks of memory for use with
	77	hardware components that do not support I/O map nor scatter-gather.
	78
	79	You can disable CMA by specifying "cma=0" on the kernel's command
	80	line.
	81
	82	For more information see <include/linux/dma-contiguous.h>.
	83	If unsure, say "n".
	84
	85	if DMA_CMA
	86	comment "Default contiguous memory area size:"
	87
	88	config CMA_SIZE_MBYTES
	89	int "Size in Mega Bytes"
	90	depends on !CMA_SIZE_SEL_PERCENTAGE
	91	default 0 if X86
	92	default 16
	93	help
	94	Defines the size (in MiB) of the default memory area for Contiguous
	95	Memory Allocator. If the size of 0 is selected, CMA is disabled by
	96	default, but it can be enabled by passing cma=size[MG] to the kernel.
	97
	98
	99	config CMA_SIZE_PERCENTAGE
	100	int "Percentage of total memory"
	101	depends on !CMA_SIZE_SEL_MBYTES
	102	default 0 if X86
	103	default 10
	104	help
	105	Defines the size of the default memory area for Contiguous Memory
	106	Allocator as a percentage of the total memory in the system.
	107	If 0 percent is selected, CMA is disabled by default, but it can be
	108	enabled by passing cma=size[MG] to the kernel.
	109
	110	choice
	111	prompt "Selected region size"
	112	default CMA_SIZE_SEL_MBYTES
	113
	114	config CMA_SIZE_SEL_MBYTES
	115	bool "Use mega bytes value only"
	116
	117	config CMA_SIZE_SEL_PERCENTAGE
	118	bool "Use percentage value only"
	119
	120	config CMA_SIZE_SEL_MIN
	121	bool "Use lower value (minimum)"
	122
	123	config CMA_SIZE_SEL_MAX
	124	bool "Use higher value (maximum)"
	125
	126	endchoice
	127
	128	config CMA_ALIGNMENT
	129	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
	130	range 4 12
	131	default 8
	132	help
	133	DMA mapping framework by default aligns all buffers to the smallest
	134	PAGE_SIZE order which is greater than or equal to the requested buffer
135	size. This works well for buffers up to a few hundreds kilobytes, but
136	for larger buffers it just a memory waste. With this parameter you can
137	specify the maximum PAGE_SIZE order for contiguous buffers. Larger
138	buffers will be aligned only to this specified order. The order is
139	expressed as a power of two multiplied by the PAGE_SIZE.
140
141	For example, if your system defaults to 4KiB pages, the order value
142	of 8 means that the buffers will be aligned up to 1MiB only.
143
144	If unsure, leave the default value "8".
145
146	endif
147
70ca7ba2 AS	148	config DMA_API_DEBUG
	149	bool "Enable debugging of DMA-API usage"
	150	select NEED_DMA_MAP_STATE
	151	help
	152	Enable this option to debug the use of the DMA API by device drivers.
	153	With this option you will be able to detect common bugs in device
	154	drivers like double-freeing of DMA mappings or freeing mappings that
	155	were never allocated.
	156
	157	This also attempts to catch cases where a page owned by DMA is
	158	accessed by the cpu in a way that could cause data corruption. For
	159	example, this enables cow_user_page() to check that the source page is
	160	not undergoing DMA.
	161
	162	This option causes a performance degradation. Use only if you want to
	163	debug device drivers and dma interactions.
	164
	165	If unsure, say N.
	166
	167	config DMA_API_DEBUG_SG
	168	bool "Debug DMA scatter-gather usage"
	169	default y
	170	depends on DMA_API_DEBUG
	171	help
	172	Perform extra checking that callers of dma_map_sg() have respected the
	173	appropriate segment length/boundary limits for the given device when
	174	preparing DMA scatterlists.
	175
	176	This is particularly likely to have been overlooked in cases where the
	177	dma_map_sg() API is used for general bulk mapping of pages rather than
	178	preparing literal scatter-gather descriptors, where there is a risk of
	179	unexpected behaviour from DMA API implementations if the scatterlist
	180	is technically out-of-spec.
	181
	182	If unsure, say N.