svn commit: r308327 - stable/11/sys/arm/include

[Michal Meloun]

Author: mmel
Date: Sat Nov  5 04:36:12 2016
New Revision: 308327
URL: https://svnweb.freebsd.org/changeset/base/308327

Log:
  MFC r306667,r306668:
  
    r306667:
      ARM: Add atomic_swap_64(). It's need by linuxkpi and drm-next-4.7.
    r306668:
      ARM: Add mising early clobber modifier in atomic_swap_32().

Modified:
  stable/11/sys/arm/include/atomic-v6.h
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/arm/include/atomic-v6.h
==============================================================================
--- stable/11/sys/arm/include/atomic-v6.h	Sat Nov  5 04:32:46 2016	(r308326)
+++ stable/11/sys/arm/include/atomic-v6.h	Sat Nov  5 04:36:12 2016	(r308327)
@@ -652,7 +652,7 @@ atomic_swap_32(volatile uint32_t *p, uin
 	    "   teq	%[exf], #0			\n"
 	    "   it	ne				\n"
 	    "   bne	1b				\n"
-	    : [ret] "=r"  (ret),
+	    : [ret] "=&r"  (ret),
 	      [exf] "=&r" (exflag)
 	    : [val] "r"  (v),
 	      [ptr] "r"  (p)
@@ -660,6 +660,26 @@ atomic_swap_32(volatile uint32_t *p, uin
 	return (ret);
 }
 
+static __inline uint64_t
+atomic_swap_64(volatile uint64_t *p, uint64_t v)
+{
+	uint64_t ret;
+	uint32_t exflag;
+
+	__asm __volatile(
+	    "1: ldrexd	%Q[ret], %R[ret], [%[ptr]]		\n"
+	    "   strexd	%[exf], %Q[val], %R[val], [%[ptr]]	\n"
+	    "   teq	%[exf], #0				\n"
+	    "   it	ne					\n"
+	    "   bne	1b					\n"
+	    : [ret] "=&r" (ret),
+	      [exf] "=&r" (exflag)
+	    : [val] "r"   (v),
+	      [ptr] "r"   (p)
+	    : "cc", "memory");
+	return (ret);
+}
+
 #undef ATOMIC_ACQ_REL
 #undef ATOMIC_ACQ_REL_LONG