svn commit: r326161 - head/sys/i386/include

[Hans Petter Selasky]

Author: hselasky
Date: Fri Nov 24 12:10:42 2017
New Revision: 326161
URL: https://svnweb.freebsd.org/changeset/base/326161

Log:
  Implement atomic_fetchadd_64() for i386. This function is needed by the
  atomic64 header file in the LinuxKPI for i386.
  
  Reviewed by:	kib
  MFC after:	1 week
  Sponsored by:	Mellanox Technologies

Modified:
  head/sys/i386/include/atomic.h

Modified: head/sys/i386/include/atomic.h
==============================================================================
--- head/sys/i386/include/atomic.h	Fri Nov 24 12:08:50 2017	(r326160)
+++ head/sys/i386/include/atomic.h	Fri Nov 24 12:10:42 2017	(r326161)
@@ -129,6 +129,7 @@ int		atomic_cmpset_64(volatile uint64_t *, uint64_t, u
 uint64_t	atomic_load_acq_64(volatile uint64_t *);
 void		atomic_store_rel_64(volatile 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 */
 
@@ -563,6 +564,17 @@ 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 */