[U-Boot] [RFC PATCH 10/12] linux_compat: introduce GFP_DMA flag for kmalloc()

[Masahiro Yamada]

It does not seem efficient to always return cache-aligned memory.
Return aligned memory only when GFP_DMA flag is given.

My main motivation for this commit is to refactor device_probe()
and device_free() in the next commit.  DM_FLAG_ALLOC_PRIV_DMA
should be handled more easily.

Signed-off-by: Masahiro Yamada <yamada.masahiro at socionext.com>
---

 include/linux/compat.h | 1 +
 lib/linux_compat.c     | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 64988bf..8b7f8ef 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -41,6 +41,7 @@ extern struct p_current *current;
 #define GFP_NOFS ((gfp_t) 0)
 #define GFP_USER ((gfp_t) 0)
 #define __GFP_NOWARN ((gfp_t) 0)
+#define GFP_DMA		((__force gfp_t)0x01u)
 #define __GFP_ZERO	((__force gfp_t)0x8000u) /* Return zeroed page on success */
 
 void *kmalloc(size_t size, int flags);
diff --git a/lib/linux_compat.c b/lib/linux_compat.c
index a936a7e..6da0cfa 100644
--- a/lib/linux_compat.c
+++ b/lib/linux_compat.c
@@ -18,7 +18,10 @@ void *kmalloc(size_t size, int flags)
 {
 	void *p;
 
-	p = memalign(ARCH_DMA_MINALIGN, size);
+	if (flags & GFP_DMA)
+		p = memalign(ARCH_DMA_MINALIGN, size);
+	else
+		p = malloc(size);
 	if (flags & __GFP_ZERO)
 		memset(p, 0, size);
 
-- 
1.9.1