From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
We want io.h primitives (readb(), etc.) to be extern inline.
However, that requires the backing out-of-line implementation
somewhere, preferably kept in sync with the inline ones.
The way it's done is __EXTERN_INLINE macro that defaults to
extern inline, but can be overridden in compilation unit where
the out-of-line instance will be.
That works, but it's brittle - we *must* make sure that asm/io.h
is the very first include in such compilation units. There'd
been a bunch of bugs of that sort in the past.
Another issue is the choice of overriding definition for
__EXTERN_INLINE; it must be either 'inline' or empty. Either
will do for compilation purposes - inline void foo(...) {...}
(without extern or static) is going to generate out-of-line
instance. The difference is that 'definition without a
prototype' heuristics trigger on
void foo(void)
{
...
}
but not on
inline void foo(void)
{
...
}
Most of the overrides go for 'inline'; in two cases (sys_jensen
and core_t2) __EXTERN_INLINE is defined as empty. Without
-Wmissing-prototypes it didn't matter, but now that we have
that thing always on...
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/alpha/kernel/core_t2.c | 2 +-
arch/alpha/kernel/sys_jensen.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/alpha/kernel/core_t2.c b/arch/alpha/kernel/core_t2.c
index 98d5b6ff8a76..3d72d90624f1 100644
--- a/arch/alpha/kernel/core_t2.c
+++ b/arch/alpha/kernel/core_t2.c
@@ -10,7 +10,7 @@
* Code common to all T2 core logic chips.
*/
-#define __EXTERN_INLINE
+#define __EXTERN_INLINE inline
#include <asm/io.h>
#include <asm/core_t2.h>
#undef __EXTERN_INLINE
diff --git a/arch/alpha/kernel/sys_jensen.c b/arch/alpha/kernel/sys_jensen.c
index 5c9c88428124..a1bb1c4a7e93 100644
--- a/arch/alpha/kernel/sys_jensen.c
+++ b/arch/alpha/kernel/sys_jensen.c
@@ -7,7 +7,7 @@
*
* Code supporting the Jensen.
*/
-#define __EXTERN_INLINE
+#define __EXTERN_INLINE inline
#include <asm/io.h>
#include <asm/jensen.h>
#undef __EXTERN_INLINE
--
2.39.2
