1 files changed, 19 insertions, 0 deletions
diff --git a/lib9/lock-Irix-mips.s b/lib9/lock-Irix-mips.s
new file mode 100644
index 00000000..40606e93
--- /dev/null
+++ b/lib9/lock-Irix-mips.s
@@ -0,0 +1,19 @@
+#include <sys/regdef.h>
+#include <sys/asm.h>
+
+/*
+ * lock from r4000 book
+ */
+LEAF(canlock)
+	.set 	noreorder
+1:
+	ll	t0,0(a0)		/* a0 is argument */
+	or	t1, t0, 1
+	sc	t1,0(a0)
+	beq	t1,zero,1b	
+	nop
+	j	$31			/* lock held */
+	xor	v0, t0, 1
+
+	.set 	reorder
+	END(canlock)