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authorMarek Szyprowski <m.szyprowski@samsung.com>2011-12-29 13:09:51 +0100
committerMarek Szyprowski <m.szyprowski@samsung.com>2012-05-21 15:09:37 +0200
commitc64be2bb1c6eb43c838b2c6d57b074078be208dd (patch)
treed0720eda4a440ff91f3296b0f90cc53ac514d4b9 /include/asm-generic
parent49f223a9cd96c7293d7258ff88c2bdf83065f69c (diff)
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drivers: add Contiguous Memory Allocator
The Contiguous Memory Allocator is a set of helper functions for DMA mapping framework that improves allocations of contiguous memory chunks. CMA grabs memory on system boot, marks it with MIGRATE_CMA migrate type and gives back to the system. Kernel is allowed to allocate only movable pages within CMA's managed memory so that it can be used for example for page cache when DMA mapping do not use it. On dma_alloc_from_contiguous() request such pages are migrated out of CMA area to free required contiguous block and fulfill the request. This allows to allocate large contiguous chunks of memory at any time assuming that there is enough free memory available in the system. This code is heavily based on earlier works by Michal Nazarewicz. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Rob Clark <rob.clark@linaro.org> Tested-by: Ohad Ben-Cohen <ohad@wizery.com> Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org> Tested-by: Robert Nelson <robertcnelson@gmail.com> Tested-by: Barry Song <Baohua.Song@csr.com>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/dma-contiguous.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/asm-generic/dma-contiguous.h b/include/asm-generic/dma-contiguous.h
new file mode 100644
index 000000000000..c544356b374b
--- /dev/null
+++ b/include/asm-generic/dma-contiguous.h
@@ -0,0 +1,28 @@
+#ifndef ASM_DMA_CONTIGUOUS_H
+#define ASM_DMA_CONTIGUOUS_H
+
+#ifdef __KERNEL__
+#ifdef CONFIG_CMA
+
+#include <linux/device.h>
+#include <linux/dma-contiguous.h>
+
+static inline struct cma *dev_get_cma_area(struct device *dev)
+{
+ if (dev && dev->cma_area)
+ return dev->cma_area;
+ return dma_contiguous_default_area;
+}
+
+static inline void dev_set_cma_area(struct device *dev, struct cma *cma)
+{
+ if (dev)
+ dev->cma_area = cma;
+ if (!dev || !dma_contiguous_default_area)
+ dma_contiguous_default_area = cma;
+}
+
+#endif
+#endif
+
+#endif