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authorJoonsoo Kim <iamjoonsoo.kim@lge.com>2014-08-06 16:05:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-06 18:01:16 -0700
commita254129e8686bff7a340b58f35241b04927e81c0 (patch)
tree90828b720ab7221a0f13c2fe3b15f997e64ea0c3 /include/linux/cma.h
parente0bdb37d95dd44086159607e571fd70f6b62dc2d (diff)
CMA: generalize CMA reserved area management functionality
Currently, there are two users on CMA functionality, one is the DMA subsystem and the other is the KVM on powerpc. They have their own code to manage CMA reserved area even if they looks really similar. From my guess, it is caused by some needs on bitmap management. KVM side wants to maintain bitmap not for 1 page, but for more size. Eventually it use bitmap where one bit represents 64 pages. When I implement CMA related patches, I should change those two places to apply my change and it seem to be painful to me. I want to change this situation and reduce future code management overhead through this patch. This change could also help developer who want to use CMA in their new feature development, since they can use CMA easily without copying & pasting this reserved area management code. In previous patches, we have prepared some features to generalize CMA reserved area management and now it's time to do it. This patch moves core functions to mm/cma.c and change DMA APIs to use these functions. There is no functional change in DMA APIs. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Alexander Graf <agraf@suse.de> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Gleb Natapov <gleb@kernel.org> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/cma.h')
-rw-r--r--include/linux/cma.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/cma.h b/include/linux/cma.h
new file mode 100644
index 000000000000..f6f7809acb98
--- /dev/null
+++ b/include/linux/cma.h
@@ -0,0 +1,27 @@
+#ifndef __CMA_H__
+#define __CMA_H__
+
+/*
+ * There is always at least global CMA area and a few optional
+ * areas configured in kernel .config.
+ */
+#ifdef CONFIG_CMA_AREAS
+#define MAX_CMA_AREAS (1 + CONFIG_CMA_AREAS)
+
+#else
+#define MAX_CMA_AREAS (0)
+
+#endif
+
+struct cma;
+
+extern phys_addr_t cma_get_base(struct cma *cma);
+extern unsigned long cma_get_size(struct cma *cma);
+
+extern int __init cma_declare_contiguous(phys_addr_t size,
+ phys_addr_t base, phys_addr_t limit,
+ phys_addr_t alignment, unsigned int order_per_bit,
+ struct cma **res_cma, bool fixed);
+extern struct page *cma_alloc(struct cma *cma, int count, unsigned int align);
+extern bool cma_release(struct cma *cma, struct page *pages, int count);
+#endif