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>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index 89c2c29f154b..847f9f793618 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -132,6 +132,11 @@ SECTIONS
                 *(.popc_6insn_patch)
                 __popc_6insn_patch_end = .;
         }
+        .pause_patch : {
+                __pause_patch = .;
+                *(.pause_patch)
+                __pause_patch_end = .;
+        }
         PERCPU_SECTION(SMP_CACHE_BYTES)
 
         . = ALIGN(PAGE_SIZE);