Introduce locking primitives using CAS instruction
The ARMv8v.1 architecture extension has introduced support for far
atomics, which includes compare-and-swap. Compare and Swap instruction
is only available for AArch64.
Introduce build options to choose the architecture versions to target
ARM Trusted Firmware:
- ARM_ARCH_MAJOR: selects the major version of target ARM
Architecture. Default value is 8.
- ARM_ARCH_MINOR: selects the minor version of target ARM
Architecture. Default value is 0.
When:
(ARM_ARCH_MAJOR > 8) || ((ARM_ARCH_MAJOR == 8) && (ARM_ARCH_MINOR >= 1)),
for AArch64, Compare and Swap instruction is used to implement spin
locks. Otherwise, the implementation falls back to using
load-/store-exclusive instructions.
Update user guide, and introduce a section in Firmware Design guide to
summarize support for features introduced in ARMv8 Architecture
Extensions.
Change-Id: I73096a0039502f7aef9ec6ab3ae36680da033f16
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 2312d2c..93db2d6 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2017, 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:
@@ -81,6 +81,16 @@
$(and $(patsubst 0,,$(value $(1))),$(patsubst 1,,$(value $(1))),$(error $(1) must be boolean))
endef
+0-9 := 0 1 2 3 4 5 6 7 8 9
+
+# Function to verify that a given option $(1) contains a numeric value
+define assert_numeric
+$(if $($(1)),,$(error $(1) must not be empty))
+$(eval __numeric := $($(1)))
+$(foreach d,$(0-9),$(eval __numeric := $(subst $(d),,$(__numeric))))
+$(if $(__numeric),$(error $(1) must be numeric))
+endef
+
# IMG_LINKERFILE defines the linker script corresponding to a BL stage
# $(1) = BL stage (2, 30, 31, 32, 33)
define IMG_LINKERFILE