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

# SPDX-License-Identifier: GPL-2.0-only

config NO_DMA
	bool

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

#
# 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

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 DMA_NONCOHERENT_CACHE_SYNC
	bool

config DMA_VIRT_OPS
	bool
	depends on HAS_DMA

config SWIOTLB
	bool
	select NEED_DMA_MAP_STATE

#
# 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_REMAP
	bool
	depends on MMU
	select DMA_NONCOHERENT_MMAP

config DMA_DIRECT_REMAP
	bool
	select DMA_REMAP
	select DMA_COHERENT_POOL

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	2
846f9e1f CH	3	config NO_DMA
	4	bool
	5
cf65a0f6 CH	6	config HAS_DMA
	7	bool
	8	depends on !NO_DMA
	9	default y
	10
	11	config NEED_SG_DMA_LENGTH
	12	bool
	13
	14	config NEED_DMA_MAP_STATE
	15	bool
	16
	17	config ARCH_DMA_ADDR_T_64BIT
	18	def_bool 64BIT \|\| PHYS_ADDR_T_64BIT
	19
f3ecc0ff CH	20	config ARCH_HAS_DMA_COHERENCE_H
	21	bool
	22
11ddce15 CH	23	config ARCH_HAS_DMA_SET_MASK
	24	bool
	25
419e2f18 CH	26	#
	27	# Select this option if the architecture needs special handling for
	28	# DMA_ATTR_WRITE_COMBINE. Normally the "uncached" mapping should be what
	29	# people thing of when saying write combine, so very few platforms should
	30	# need to enable this.
	31	#
	32	config ARCH_HAS_DMA_WRITE_COMBINE
	33	bool
	34
ff4c25f2	35	config DMA_DECLARE_COHERENT
cf65a0f6 CH	36	bool
cf65a0f6 CH	37
347cb6af CH	38	config ARCH_HAS_SETUP_DMA_OPS
	39	bool
	40
dc2acded	41	config ARCH_HAS_TEARDOWN_DMA_OPS
cf65a0f6 CH	42	bool
	43
	44	config ARCH_HAS_SYNC_DMA_FOR_DEVICE
	45	bool
	46
	47	config ARCH_HAS_SYNC_DMA_FOR_CPU
	48	bool
	49	select NEED_DMA_MAP_STATE
	50
684f7e91 CH	51	config ARCH_HAS_SYNC_DMA_FOR_CPU_ALL
	52	bool
	53
13bf5ced CH	54	config ARCH_HAS_DMA_PREP_COHERENT
	55	bool
	56
9087c375 TL	57	config ARCH_HAS_FORCE_DMA_UNENCRYPTED
	58	bool
	59
cf65a0f6 CH	60	config DMA_NONCOHERENT_CACHE_SYNC
cf65a0f6 CH	61	bool
cf65a0f6 CH	62
	63	config DMA_VIRT_OPS
	64	bool
	65	depends on HAS_DMA
	66
	67	config SWIOTLB
	68	bool
cf65a0f6	69	select NEED_DMA_MAP_STATE
f0edfea8	70
34dc0ea6 CH	71	#
	72	# Should be selected if we can mmap non-coherent mappings to userspace.
	73	# The only thing that is really required is a way to set an uncached bit
	74	# in the pagetables
	75	#
	76	config DMA_NONCOHERENT_MMAP
1fbf57d0	77	default y if !MMU
34dc0ea6 CH	78	bool
34dc0ea6 CH	79
dbed452a	80	config DMA_COHERENT_POOL
d07ae4c4	81	select GENERIC_ALLOCATOR
dbed452a DR	82	bool
dbed452a DR	83
f0edfea8	84	config DMA_REMAP
dbed452a	85	bool
f0edfea8	86	depends on MMU
34dc0ea6	87	select DMA_NONCOHERENT_MMAP
70ca7ba2	88
e860c299 DR	89	config DMA_DIRECT_REMAP
e860c299 DR	90	bool
dbed452a	91	select DMA_REMAP
e860c299 DR	92	select DMA_COHERENT_POOL
e860c299 DR	93
ddb26d8e CH	94	config DMA_CMA
	95	bool "DMA Contiguous Memory Allocator"
	96	depends on HAVE_DMA_CONTIGUOUS && CMA
	97	help
	98	This enables the Contiguous Memory Allocator which allows drivers
	99	to allocate big physically-contiguous blocks of memory for use with
	100	hardware components that do not support I/O map nor scatter-gather.
	101
	102	You can disable CMA by specifying "cma=0" on the kernel's command
	103	line.
	104
	105	For more information see <include/linux/dma-contiguous.h>.
	106	If unsure, say "n".
	107
	108	if DMA_CMA
	109	comment "Default contiguous memory area size:"
	110
	111	config CMA_SIZE_MBYTES
	112	int "Size in Mega Bytes"
	113	depends on !CMA_SIZE_SEL_PERCENTAGE
	114	default 0 if X86
	115	default 16
	116	help
	117	Defines the size (in MiB) of the default memory area for Contiguous
	118	Memory Allocator. If the size of 0 is selected, CMA is disabled by
	119	default, but it can be enabled by passing cma=size[MG] to the kernel.
	120
	121
	122	config CMA_SIZE_PERCENTAGE
	123	int "Percentage of total memory"
	124	depends on !CMA_SIZE_SEL_MBYTES
	125	default 0 if X86
	126	default 10
	127	help
	128	Defines the size of the default memory area for Contiguous Memory
	129	Allocator as a percentage of the total memory in the system.
	130	If 0 percent is selected, CMA is disabled by default, but it can be
	131	enabled by passing cma=size[MG] to the kernel.
	132
	133	choice
	134	prompt "Selected region size"
	135	default CMA_SIZE_SEL_MBYTES
	136
	137	config CMA_SIZE_SEL_MBYTES
	138	bool "Use mega bytes value only"
	139
	140	config CMA_SIZE_SEL_PERCENTAGE
	141	bool "Use percentage value only"
	142
	143	config CMA_SIZE_SEL_MIN
	144	bool "Use lower value (minimum)"
	145
	146	config CMA_SIZE_SEL_MAX
	147	bool "Use higher value (maximum)"
	148
	149	endchoice
	150
	151	config CMA_ALIGNMENT
	152	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
	153	range 4 12
	154	default 8
	155	help
	156	DMA mapping framework by default aligns all buffers to the smallest
	157	PAGE_SIZE order which is greater than or equal to the requested buffer
158	size. This works well for buffers up to a few hundreds kilobytes, but
159	for larger buffers it just a memory waste. With this parameter you can
160	specify the maximum PAGE_SIZE order for contiguous buffers. Larger
161	buffers will be aligned only to this specified order. The order is
162	expressed as a power of two multiplied by the PAGE_SIZE.
163
164	For example, if your system defaults to 4KiB pages, the order value
165	of 8 means that the buffers will be aligned up to 1MiB only.
166
167	If unsure, leave the default value "8".
168
169	endif
170
70ca7ba2 AS	171	config DMA_API_DEBUG
	172	bool "Enable debugging of DMA-API usage"
	173	select NEED_DMA_MAP_STATE
	174	help
	175	Enable this option to debug the use of the DMA API by device drivers.
	176	With this option you will be able to detect common bugs in device
	177	drivers like double-freeing of DMA mappings or freeing mappings that
	178	were never allocated.
	179
	180	This also attempts to catch cases where a page owned by DMA is
	181	accessed by the cpu in a way that could cause data corruption. For
	182	example, this enables cow_user_page() to check that the source page is
	183	not undergoing DMA.
	184
	185	This option causes a performance degradation. Use only if you want to
	186	debug device drivers and dma interactions.
	187
	188	If unsure, say N.
	189
	190	config DMA_API_DEBUG_SG
	191	bool "Debug DMA scatter-gather usage"
	192	default y
	193	depends on DMA_API_DEBUG
	194	help
	195	Perform extra checking that callers of dma_map_sg() have respected the
	196	appropriate segment length/boundary limits for the given device when
	197	preparing DMA scatterlists.
	198
	199	This is particularly likely to have been overlooked in cases where the
	200	dma_map_sg() API is used for general bulk mapping of pages rather than
	201	preparing literal scatter-gather descriptors, where there is a risk of
	202	unexpected behaviour from DMA API implementations if the scatterlist
	203	is technically out-of-spec.
	204
	205	If unsure, say N.