voron

commit 9933ed07832f27117618960b54dcd7a46d91cd63
parent a116d94e7f69f4757bc1cb8c178df0af06215645
Author: oblique <psyberbits@gmail.com>
Date:   Wed, 31 Oct 2012 23:53:12 +0200

add uatomic_add_return()

Diffstat:
M
include/atomic.h
 | 
23
+++++++++++++++++++++--

1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/include/atomic.h b/include/atomic.h
@@ -7,8 +7,9 @@ typedef struct {
 	u32 counter;
 } uatomic_t;
 
-#define UATOMIC_INIT(i)	{ (i) }
-#define uatomic_read(v)	(__uatomic_read(v).counter)
+#define UATOMIC_INIT(i)		{ (i) }
+#define uatomic_read(v)		(__uatomic_read(v).counter)
+#define uatomic_add_return(i, v)	(__uatomic_add_return(i, v).counter)
 
 static inline uatomic_t
 __uatomic_read(uatomic_t *v)
@@ -61,4 +62,22 @@ uatomic_add(u32 i, uatomic_t *v)
 	);
 }
 
+static inline uatomic_t
+__uatomic_add_return(u32 i, uatomic_t *v)
+{
+	uatomic_t r;
+	asm volatile (
+		"1:			\n\t"
+		"ldrex %0, [%2]		\n\t"
+		"add %0, %0, %1		\n\t"
+		"strex v1, %0, [%2]	\n\t"
+		"teq v1, #0		\n\t"
+		"bne 1b			\n\t"
+		: "=&r" (r)
+		: "r" (i), "r" (v)
+		: "v1", "memory"
+	);
+	return r;
+}
+
 #endif	/* __ATOMIC_H */