[U-Boot] [PATCH v2 10/14] linux_compat: introduce GFP_DMA flag for kmalloc()

Masahiro Yamada
2015-07-13T04:17:13Z

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@socionext.com>
---

Changes in v2: None

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 fbebf91..13386c9 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