1 files changed, 89 insertions, 0 deletions

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 9aa618acfe97..9b21469482ae 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -192,4 +192,93 @@ config DMA_SHARED_BUFFER
           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