sparc64: Use pause instruction when available.
In atomic backoff and cpu_relax(), use the pause instruction
found on SPARC-T4 and later.
It makes the cpu strand unselectable for the given number of
cycles, unless an intervening disrupting trap occurs.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/entry.h b/arch/sparc/kernel/entry.h
index 0c218e4..51742df 100644
--- a/arch/sparc/kernel/entry.h
+++ b/arch/sparc/kernel/entry.h
@@ -59,6 +59,13 @@
extern struct popc_6insn_patch_entry __popc_6insn_patch,
__popc_6insn_patch_end;
+struct pause_patch_entry {
+ unsigned int addr;
+ unsigned int insns[3];
+};
+extern struct pause_patch_entry __pause_patch,
+ __pause_patch_end;
+
extern void __init per_cpu_patch(void);
extern void sun4v_patch_1insn_range(struct sun4v_1insn_patch_entry *,
struct sun4v_1insn_patch_entry *);