On 7/13/2016 10:01 PM, Stefano Stabellini wrote:
On Wed, 13 Jul 2016, Corneliu ZUZU wrote:
Create a common-side <xen/atomic.h> to establish, among others, prototypes of
atomic functions called from common-code. Done to avoid introducing
inconsistencies between arch-side <asm/atomic.h> headers when we make subtle
changes to one of them.
Some arm-side macros had to be turned into inline functions in the process.
Removed outdated comment ("NB. I've [...]").
Signed-off-by: Corneliu ZUZU <cz...@bitdefender.com>
Suggested-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Andrew Cooper <andrew.coop...@citrix.com>
---
Changed since v1:
* removed comments that were duplicate between asm-x86/atomic.h and
xen/atomic.h
* remove outdated comment ("NB. [...]")
* add atomic_cmpxchg doc-comment
* don't use yoda condition
---
xen/include/asm-arm/atomic.h | 45 ++++++++----
xen/include/asm-x86/atomic.h | 103 +-------------------------
xen/include/xen/atomic.h | 171 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 202 insertions(+), 117 deletions(-)
create mode 100644 xen/include/xen/atomic.h
diff --git a/xen/include/asm-arm/atomic.h b/xen/include/asm-arm/atomic.h
index e8f7340..01af43b 100644
--- a/xen/include/asm-arm/atomic.h
+++ b/xen/include/asm-arm/atomic.h
@@ -2,6 +2,7 @@
#define __ARCH_ARM_ATOMIC__
#include <xen/config.h>
+#include <xen/atomic.h>
#include <xen/prefetch.h>
#include <asm/system.h>
@@ -95,15 +96,6 @@ void __bad_atomic_size(void);
default: __bad_atomic_size(); break; \
} \
})
-
-/*
- * NB. I've pushed the volatile qualifier into the operations. This allows
- * fast accessors such as _atomic_read() and _atomic_set() which don't give
- * the compiler a fit.
- */
-typedef struct { int counter; } atomic_t;
-
-#define ATOMIC_INIT(i) { (i) }
/*
* On ARM, ordinary assignment (str instruction) doesn't clear the local
@@ -141,12 +133,35 @@ static inline void _atomic_set(atomic_t *v, int i)
#define atomic_inc_return(v) (atomic_add_return(1, v))
#define atomic_dec_return(v) (atomic_sub_return(1, v))
What about atomic_inc_return and atomic_dec_return? Doesn't it make
sense to do this for all of them, since we are at it? I believe there
are also a couple more which are #define'd.
Those don't seem to be implemented for X86 and neither are they referred
from common code (probably because they really aren't defined for X86).
-#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
-#define atomic_inc(v) atomic_add(1, v)
-#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
-#define atomic_dec(v) atomic_sub(1, v)
-#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
-#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0)
+static inline int atomic_sub_and_test(int i, atomic_t *v)
+{
+ return atomic_sub_return(i, v) == 0;
+}
+
+static inline void atomic_inc(atomic_t *v)
+{
+ atomic_add(1, v);
+}
+
+static inline int atomic_inc_and_test(atomic_t *v)
+{
+ return atomic_add_return(1, v) == 0;
+}
+
+static inline void atomic_dec(atomic_t *v)
+{
+ atomic_sub(1, v);
+}
+
+static inline int atomic_dec_and_test(atomic_t *v)
+{
+ return atomic_sub_return(1, v) == 0;
+}
+
+static inline int atomic_add_negative(int i, atomic_t *v)
+{
+ return atomic_add_return(i, v) < 0;
+}
#endif /* __ARCH_ARM_ATOMIC__ */
Thanks,
Zuzu C.
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