[04/15] backports: add some more atomic functions

Commit Message

Johannes Berg Feb. 21, 2020, 8:56 a.m. UTC

From: Johannes Berg <[e-mail]>

Some of the new fetch atomics are now required, add them by
using the _return ones and changing the value accordingly.

Signed-off-by: Johannes Berg <[e-mail]>
---
 backport/backport-include/linux/atomic.h | 32 ++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

Patch

diff --git a/backport/backport-include/linux/atomic.h b/backport/backport-include/linux/atomic.h
index 9ceb586e864a..6669831ca8a9 100644
--- a/backport/backport-include/linux/atomic.h
+++ b/backport/backport-include/linux/atomic.h
@@ -60,4 +60,36 @@  static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
 #endif
 #endif
 
+#ifndef __atomic_pre_full_fence
+#define __atomic_pre_full_fence         smp_mb__before_atomic
+#endif
+
+#ifndef __atomic_post_full_fence
+#define __atomic_post_full_fence        smp_mb__after_atomic
+#endif
+
+#if LINUX_VERSION_IS_LESS(4,8,0)
+static inline int
+atomic_fetch_add(int i, atomic_t *v)
+{
+	return atomic_add_return(i, v) - i;
+}
+
+static inline int
+atomic_fetch_sub(int i, atomic_t *v)
+{
+	return atomic_sub_return(i, v) + i;
+}
+#endif
+
+#ifndef atomic_fetch_add_relaxed
+#define atomic_fetch_add_relaxed atomic_fetch_add
+#endif
+
+#ifndef atomic_fetch_sub_relaxed
+#define atomic_fetch_sub_acquire atomic_fetch_sub
+#define atomic_fetch_sub_release atomic_fetch_sub
+#define atomic_fetch_sub_relaxed atomic_fetch_sub
+#endif
+
 #endif /* __BP_ATOMIC_H */