* the optimal version - two calls, each with their own speculation
* trap should their return address end up getting used, in a loop.
*/
+#ifdef CONFIG_X86_64
#define __FILL_RETURN_BUFFER(reg, nr) \
mov $(nr/2), reg; \
771: \
jnz 771b; \
/* barrier for jnz misprediction */ \
lfence;
+#else
+/*
+ * i386 doesn't unconditionally have LFENCE, as such it can't
+ * do a loop.
+ */
+#define __FILL_RETURN_BUFFER(reg, nr) \
+ .rept nr; \
+ __FILL_RETURN_SLOT; \
+ .endr; \
+ add $(BITS_PER_LONG/8) * nr, %_ASM_SP;
+#endif
/*
* Stuff a single RSB slot.