linux/drivers/base/Kconfig

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menu "Generic Driver Options"
config UEVENT_HELPER_PATH
string "path to uevent helper"
depends on HOTPLUG
default ""
help
Path to uevent helper program forked by the kernel for
every uevent.
Before the switch to the netlink-based uevent source, this was
used to hook hotplug scripts into kernel device events. It
usually pointed to a shell script at /sbin/hotplug.
This should not be used today, because usual systems create
many events at bootup or device discovery in a very short time
frame. One forked process per event can create so many processes
that it creates a high system load, or on smaller systems
it is known to create out-of-memory situations during bootup.
To disable user space helper program execution at early boot
time specify an empty string here. This setting can be altered
via /proc/sys/kernel/hotplug or via /sys/kernel/uevent_helper
later at runtime.
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
config DEVTMPFS
bool "Maintain a devtmpfs filesystem to mount at /dev"
depends on HOTPLUG
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
help
This creates a tmpfs/ramfs filesystem instance early at bootup.
In this filesystem, the kernel driver core maintains device
nodes with their default names and permissions for all
registered devices with an assigned major/minor number.
Userspace can modify the filesystem content as needed, add
symlinks, and apply needed permissions.
It provides a fully functional /dev directory, where usually
udev runs on top, managing permissions and adding meaningful
symlinks.
In very limited environments, it may provide a sufficient
functional /dev without any further help. It also allows simple
rescue systems, and reliably handles dynamic major/minor numbers.
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
file system will be used instead.
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
config DEVTMPFS_MOUNT
bool "Automount devtmpfs at /dev, after the kernel mounted the rootfs"
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
depends on DEVTMPFS
help
This will instruct the kernel to automatically mount the
devtmpfs filesystem at /dev, directly after the kernel has
mounted the root filesystem. The behavior can be overridden
with the commandline parameter: devtmpfs.mount=0|1.
This option does not affect initramfs based booting, here
the devtmpfs filesystem always needs to be mounted manually
after the roots is mounted.
With this option enabled, it allows to bring up a system in
rescue mode with init=/bin/sh, even when the /dev directory
on the rootfs is completely empty.
Driver Core: devtmpfs - kernel-maintained tmpfs-based /dev Devtmpfs lets the kernel create a tmpfs instance called devtmpfs very early at kernel initialization, before any driver-core device is registered. Every device with a major/minor will provide a device node in devtmpfs. Devtmpfs can be changed and altered by userspace at any time, and in any way needed - just like today's udev-mounted tmpfs. Unmodified udev versions will run just fine on top of it, and will recognize an already existing kernel-created device node and use it. The default node permissions are root:root 0600. Proper permissions and user/group ownership, meaningful symlinks, all other policy still needs to be applied by userspace. If a node is created by devtmps, devtmpfs will remove the device node when the device goes away. If the device node was created by userspace, or the devtmpfs created node was replaced by userspace, it will no longer be removed by devtmpfs. If it is requested to auto-mount it, it makes init=/bin/sh work without any further userspace support. /dev will be fully populated and dynamic, and always reflect the current device state of the kernel. With the commonly used dynamic device numbers, it solves the problem where static devices nodes may point to the wrong devices. It is intended to make the initial bootup logic simpler and more robust, by de-coupling the creation of the inital environment, to reliably run userspace processes, from a complex userspace bootstrap logic to provide a working /dev. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Jan Blunck <jblunck@suse.de> Tested-By: Harald Hoyer <harald@redhat.com> Tested-By: Scott James Remnant <scott@ubuntu.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-04-30 13:23:42 +00:00
config STANDALONE
bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
default y
help
Select this option if you don't have magic firmware for drivers that
need it.
If unsure, say Y.
config PREVENT_FIRMWARE_BUILD
bool "Prevent firmware from being built"
default y
help
Say yes to avoid building firmware. Firmware is usually shipped
with the driver and only when updating the firmware should a
rebuild be made.
If unsure, say Y here.
config FW_LOADER
tristate "Userspace firmware loading support" if EXPERT
default y
---help---
This option is provided for the case where none of the in-tree modules
require userspace firmware loading support, but a module built
out-of-tree does.
config FIRMWARE_IN_KERNEL
bool "Include in-kernel firmware blobs in kernel binary"
depends on FW_LOADER
default y
help
The kernel source tree includes a number of firmware 'blobs'
that are used by various drivers. The recommended way to
use these is to run "make firmware_install", which, after
converting ihex files to binary, copies all of the needed
binary files in firmware/ to /lib/firmware/ on your system so
that they can be loaded by userspace helpers on request.
Enabling this option will build each required firmware blob
into the kernel directly, where request_firmware() will find
them without having to call out to userspace. This may be
useful if your root file system requires a device that uses
such firmware and do not wish to use an initrd.
This single option controls the inclusion of firmware for
every driver that uses request_firmware() and ships its
firmware in the kernel source tree, which avoids a
proliferation of 'Include firmware for xxx device' options.
Say 'N' and let firmware be loaded from userspace.
config EXTRA_FIRMWARE
string "External firmware blobs to build into the kernel binary"
depends on FW_LOADER
help
This option allows firmware to be built into the kernel for the case
where the user either cannot or doesn't want to provide it from
userspace at runtime (for example, when the firmware in question is
required for accessing the boot device, and the user doesn't want to
use an initrd).
This option is a string and takes the (space-separated) names of the
firmware files -- the same names that appear in MODULE_FIRMWARE()
and request_firmware() in the source. These files should exist under
the directory specified by the EXTRA_FIRMWARE_DIR option, which is
by default the firmware subdirectory of the kernel source tree.
For example, you might set CONFIG_EXTRA_FIRMWARE="usb8388.bin", copy
the usb8388.bin file into the firmware directory, and build the kernel.
Then any request_firmware("usb8388.bin") will be satisfied internally
without needing to call out to userspace.
WARNING: If you include additional firmware files into your binary
kernel image that are not available under the terms of the GPL,
then it may be a violation of the GPL to distribute the resulting
image since it combines both GPL and non-GPL work. You should
consult a lawyer of your own before distributing such an image.
config EXTRA_FIRMWARE_DIR
string "Firmware blobs root directory"
depends on EXTRA_FIRMWARE != ""
default "firmware"
help
This option controls the directory in which the kernel build system
looks for the firmware files listed in the EXTRA_FIRMWARE option.
The default is firmware/ in the kernel source tree, but by changing
this option you can point it elsewhere, such as /lib/firmware/ or
some other directory containing the firmware files.
config DEBUG_DRIVER
bool "Driver Core verbose debug messages"
depends on DEBUG_KERNEL
help
Say Y here if you want the Driver core to produce a bunch of
debug messages to the system log. Select this if you are having a
problem with the driver core and want to see more of what is
going on.
If you are unsure about this, say N here.
config DEBUG_DEVRES
bool "Managed device resources verbose debug messages"
depends on DEBUG_KERNEL
help
This option enables kernel parameter devres.log. If set to
non-zero, devres debug messages are printed. Select this if
you are having a problem with devres or want to debug
resource management for a managed device. devres.log can be
switched on and off from sysfs node.
If you are unsure about this, Say N here.
config SYS_HYPERVISOR
bool
default n
config GENERIC_CPU_DEVICES
bool
default n
config SOC_BUS
bool
regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-11 17:59:58 +00:00
source "drivers/base/regmap/Kconfig"
dma-buf: Introduce dma buffer sharing mechanism This is the first step in defining a dma buffer sharing mechanism. A new buffer object dma_buf is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - creation of a buffer object, its association with a file pointer, and associated allocator-defined operations on that buffer. This operation is called the 'export' operation. - different devices to 'attach' themselves to this exported buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - the exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the scatterlist associated with this buffer object using map_dma_buf and unmap_dma_buf operations. Atleast one 'attach()' call is required to be made prior to calling the map_dma_buf() operation. Couple of building blocks in map_dma_buf() are added to ease introduction of sync'ing across exporter and users, and late allocation by the exporter. For this first version, this framework will work with certain conditions: - *ONLY* exporter will be allowed to mmap to userspace (outside of this framework - mmap is not a buffer object operation), - currently, *ONLY* users that do not need CPU access to the buffer are allowed. More details are there in the documentation patch. This is based on design suggestions from many people at the mini-summits[1], most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and Daniel Vetter <daniel@ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-12-26 09:23:15 +00:00
config DMA_SHARED_BUFFER
bool
dma-buf: Introduce dma buffer sharing mechanism This is the first step in defining a dma buffer sharing mechanism. A new buffer object dma_buf is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - creation of a buffer object, its association with a file pointer, and associated allocator-defined operations on that buffer. This operation is called the 'export' operation. - different devices to 'attach' themselves to this exported buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - the exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the scatterlist associated with this buffer object using map_dma_buf and unmap_dma_buf operations. Atleast one 'attach()' call is required to be made prior to calling the map_dma_buf() operation. Couple of building blocks in map_dma_buf() are added to ease introduction of sync'ing across exporter and users, and late allocation by the exporter. For this first version, this framework will work with certain conditions: - *ONLY* exporter will be allowed to mmap to userspace (outside of this framework - mmap is not a buffer object operation), - currently, *ONLY* users that do not need CPU access to the buffer are allowed. More details are there in the documentation patch. This is based on design suggestions from many people at the mini-summits[1], most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and Daniel Vetter <daniel@ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-12-26 09:23:15 +00:00
default n
select ANON_INODES
depends on EXPERIMENTAL
dma-buf: Introduce dma buffer sharing mechanism This is the first step in defining a dma buffer sharing mechanism. A new buffer object dma_buf is added, with operations and API to allow easy sharing of this buffer object across devices. The framework allows: - creation of a buffer object, its association with a file pointer, and associated allocator-defined operations on that buffer. This operation is called the 'export' operation. - different devices to 'attach' themselves to this exported buffer object, to facilitate backing storage negotiation, using dma_buf_attach() API. - the exported buffer object to be shared with the other entity by asking for its 'file-descriptor (fd)', and sharing the fd across. - a received fd to get the buffer object back, where it can be accessed using the associated exporter-defined operations. - the exporter and user to share the scatterlist associated with this buffer object using map_dma_buf and unmap_dma_buf operations. Atleast one 'attach()' call is required to be made prior to calling the map_dma_buf() operation. Couple of building blocks in map_dma_buf() are added to ease introduction of sync'ing across exporter and users, and late allocation by the exporter. For this first version, this framework will work with certain conditions: - *ONLY* exporter will be allowed to mmap to userspace (outside of this framework - mmap is not a buffer object operation), - currently, *ONLY* users that do not need CPU access to the buffer are allowed. More details are there in the documentation patch. This is based on design suggestions from many people at the mini-summits[1], most notably from Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and Daniel Vetter <daniel@ffwll.ch>. The implementation is inspired from proof-of-concept patch-set from Tomasz Stanislawski <t.stanislaws@samsung.com>, who demonstrated buffer sharing between two v4l2 devices. [2] [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement [2]: http://lwn.net/Articles/454389 Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Dave Airlie <airlied@redhat.com> Reviewed-and-Tested-by: Rob Clark <rob.clark@linaro.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-12-26 09:23:15 +00:00
help
This option enables the framework for buffer-sharing between
multiple drivers. A buffer is associated with a file using driver
APIs extension; the file's descriptor can then be passed on to other
driver.
config CMA
bool "Contiguous Memory Allocator (EXPERIMENTAL)"
depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL
select MIGRATION
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.
For more information see <include/linux/dma-contiguous.h>.
If unsure, say "n".
if CMA
config CMA_DEBUG
bool "CMA debug messages (DEVELOPMENT)"
depends on DEBUG_KERNEL
help
Turns on debug messages in CMA. This produces KERN_DEBUG
messages for every CMA call as well as various messages while
processing calls such as dma_alloc_from_contiguous().
This option does not affect warning and error messages.
comment "Default contiguous memory area size:"
config CMA_SIZE_MBYTES
int "Size in Mega Bytes"
depends on !CMA_SIZE_SEL_PERCENTAGE
default 16
help
Defines the size (in MiB) of the default memory area for Contiguous
Memory Allocator.
config CMA_SIZE_PERCENTAGE
int "Percentage of total memory"
depends on !CMA_SIZE_SEL_MBYTES
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.
choice
prompt "Selected region size"
default CMA_SIZE_SEL_ABSOLUTE
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 9
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".
config CMA_AREAS
int "Maximum count of the CMA device-private areas"
default 7
help
CMA allows to create CMA areas for particular devices. This parameter
sets the maximum number of such device private CMA areas in the
system.
If unsure, leave the default value "7".
endif
endmenu