From 17e2a84e9aa17c9ba272cb1c920e6083277bd49a Mon Sep 17 00:00:00 2001
From: Hans Petter Selasky <hselasky@FreeBSD.org>
Date: Wed, 6 Jun 2018 15:31:47 +0000
Subject: [PATCH] Rewrite code using atomic_fcmpset_int() in the LinuxKPI.

Suggested by:	mjg@
MFC after:	1 week
Sponsored by:	Mellanox Technologies
Sponsored by:	Limelight Networks
---
 sys/compat/linuxkpi/common/include/asm/atomic.h | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/sys/compat/linuxkpi/common/include/asm/atomic.h b/sys/compat/linuxkpi/common/include/asm/atomic.h
index 8a7ecdcf9d0..22cfada3ee9 100644
--- a/sys/compat/linuxkpi/common/include/asm/atomic.h
+++ b/sys/compat/linuxkpi/common/include/asm/atomic.h
@@ -239,15 +239,16 @@ static inline int
 atomic_dec_if_positive(atomic_t *v)
 {
 	int retval;
-	int curr;
+	int old;
 
-	do {
-		curr = atomic_read(v);
-		retval = curr - 1;
+	old = atomic_read(v);
+	for (;;) {
+		retval = old - 1;
 		if (unlikely(retval < 0))
 			break;
-	} while (!likely(atomic_cmpset_int(&v->counter, curr, retval)));
-
+		if (likely(atomic_fcmpset_int(&v->counter, &old, retval)))
+			break;
+	}
 	return (retval);
 }