[RFC PATCH 1/1] ARM: Ensure correct structure alignment when using compiler attribute "section"

[Lino Sanfilippo]

In some cases structures are placed into dedicated sections by means of the
"section" compiler attribute and then accessed as elements of an array (e.g when
the __clk_of_table is set up which contains all potential clock providers - see
CLK_OF_DECLARE).
But even if the size of such a structure is a multiple of the processors word
size, the linker may decide to use an even greater alignment and thus use
padding in between the structures. In this case accessing a structure as an
array element is not possible. To avoid such padding and thus allow to access
such a structure as an array element enforce an alignment of processor word size
by means of the "aligned" attribute.

Signed-off-by: Lino Sanfilippo <lsanfil@xxxxxxxxxxx>
---
 include/linux/compiler.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 33063f8..6f32128 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -371,7 +371,8 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 
 /* Simple shorthand for a section definition */
 #ifndef __section
-# define __section(S) __attribute__ ((__section__(#S)))
+# define __section(S) __attribute__ ((__section__(#S))) \
+		      __aligned(sizeof(void *))
 #endif
 
 #ifndef __visible
-- 
1.9.1

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