svn commit: r295701 - head/sys/riscv/include

[Ruslan Bukin]

Author: br
Date: Wed Feb 17 14:32:03 2016
New Revision: 295701
URL: https://svnweb.freebsd.org/changeset/base/295701

Log:
  Add the implementation of atomic_swap_32().

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

Modified: head/sys/riscv/include/atomic.h
==============================================================================
--- head/sys/riscv/include/atomic.h	Wed Feb 17 14:24:25 2016	(r295700)
+++ head/sys/riscv/include/atomic.h	Wed Feb 17 14:32:03 2016	(r295701)
@@ -310,6 +310,19 @@ atomic_readandclear_64(volatile uint64_t
 	return (ret);
 }
 
+static __inline uint32_t
+atomic_swap_32(volatile uint32_t *p, uint32_t val)
+{
+	uint32_t old;
+
+	__asm __volatile("amoswap.w %0, %2, %1"
+			: "=&r"(old), "+A" (*p)
+			: "r" (val)
+			: "memory");
+
+	return (old);
+}
+
 static __inline uint64_t
 atomic_swap_64(volatile uint64_t *p, uint64_t val)
 {