Disable non-temporal hint on Cortex-A53/57
The LDNP/STNP instructions as implemented on Cortex-A53 and
Cortex-A57 do not behave in a way most programmers expect, and will
most probably result in a significant speed degradation to any code
that employs them. The ARMv8-A architecture (see Document ARM DDI
0487A.h, section D3.4.3) allows cores to ignore the non-temporal hint
and treat LDNP/STNP as LDP/STP instead.
This patch introduces 2 new build flags:
A53_DISABLE_NON_TEMPORAL_HINT and A57_DISABLE_NON_TEMPORAL_HINT
to enforce this behaviour on Cortex-A53 and Cortex-A57. They are
enabled by default.
The string printed in debug builds when a specific CPU errata
workaround is compiled in but skipped at runtime has been
generalised, so that it can be reused for the non-temporal hint use
case as well.
Change-Id: I3e354f4797fd5d3959872a678e160322b13867a1
diff --git a/Makefile b/Makefile
index add2e9f..ac688ba 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
@@ -294,9 +294,9 @@
include plat/compat/plat_compat.mk
endif
-# Include the CPU specific operations makefile. By default all CPU errata
-# workarounds and CPU specific optimisations are disabled. This can be
-# overridden by the platform.
+# Include the CPU specific operations makefile, which provides default
+# values for all CPU errata workarounds and CPU specific optimisations.
+# This can be overridden by the platform.
include lib/cpus/cpu-ops.mk