svn commit: r326517 - stable/9/sys/i386/include

[Hans Petter Selasky]

Author: hselasky
Date: Mon Dec  4 09:48:31 2017
New Revision: 326517
URL: https://svnweb.freebsd.org/changeset/base/326517

Log:
  MFC r326161:
  Implement atomic_fetchadd_64() for i386. This function is needed by the
  atomic64 header file in the LinuxKPI for i386.
  
  Reviewed by:	kib
  Sponsored by:	Mellanox Technologies

Modified:
  stable/9/sys/i386/include/atomic.h
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/i386/include/atomic.h
==============================================================================
--- stable/9/sys/i386/include/atomic.h	Mon Dec  4 09:47:42 2017	(r326516)
+++ stable/9/sys/i386/include/atomic.h	Mon Dec  4 09:48:31 2017	(r326517)
@@ -94,6 +94,7 @@ void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_
 
 int		atomic_cmpset_64(volatile uint64_t *, uint64_t, uint64_t);
 uint64_t	atomic_swap_64(volatile uint64_t *, uint64_t);
+uint64_t	atomic_fetchadd_64(volatile uint64_t *, uint64_t);
 
 #else /* !KLD_MODULE && __GNUCLIKE_ASM */
 
@@ -478,6 +479,17 @@ atomic_swap_64(volatile uint64_t *p, uint64_t v)
 		return (atomic_swap_64_i386(p, v));
 	else
 		return (atomic_swap_64_i586(p, v));
+}
+
+static __inline uint64_t
+atomic_fetchadd_64(volatile uint64_t *p, uint64_t v)
+{
+
+	for (;;) {
+		uint64_t t = *p;
+		if (atomic_cmpset_64(p, t, t + v))
+			return (t);
+	}
 }
 
 #endif /* _KERNEL */