ARM: use arch_extension directive instead of arch argument
authorStefan Agner <stefan@agner.ch>
Mon, 27 May 2019 22:40:50 +0000 (00:40 +0200)
committerOlof Johansson <olof@lixom.net>
Wed, 19 Jun 2019 16:44:25 +0000 (09:44 -0700)
commit3fe1ee40b2a2db271513a498c475c13572dcb4c6
tree64a85ad53e8d01b6443c4f1eb1146b5465dfa1c4
parent24cb4bc8f0c9ee346826f33e6dcbdbc533cc6ad8
ARM: use arch_extension directive instead of arch argument

The LLVM Target parser currently does not allow to specify the security
extension as part of -march (see also LLVM Bug 40186 [0]). When trying
to use Clang with LLVM's integrated assembler, this leads to build
errors such as this:
  clang-8: error: the clang compiler does not support '-Wa,-march=armv7-a+sec'

Use ".arch_extension sec" to enable the security extension in a more
portable fasion. Also make sure to use ".arch armv7-a" in case a v6/v7
multi-platform kernel is being built.

Note that this is technically not exactly the same as the old code
checked for availabilty of the security extension by calling as-instr.
However, there are already other sites which use ".arch_extension sec"
unconditionally, hence de-facto we need an assembler capable of
".arch_extension sec" already today (arch/arm/mm/proc-v7.S). The
arch extension "sec" is available since binutils 2.21 according to
its documentation [1].

[0] https://bugs.llvm.org/show_bug.cgi?id=40186
[1] https://sourceware.org/binutils/docs-2.21/as/ARM-Options.html

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Mans Rullgard <mans@mansr.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
18 files changed:
arch/arm/mach-bcm/Makefile
arch/arm/mach-bcm/bcm_kona_smc.c
arch/arm/mach-exynos/Makefile
arch/arm/mach-exynos/exynos-smc.S
arch/arm/mach-exynos/sleep.S
arch/arm/mach-highbank/Makefile
arch/arm/mach-highbank/smc.S
arch/arm/mach-keystone/Makefile
arch/arm/mach-keystone/smc.S
arch/arm/mach-omap2/Makefile
arch/arm/mach-omap2/omap-headsmp.S
arch/arm/mach-omap2/omap-smc.S
arch/arm/mach-omap2/sleep33xx.S
arch/arm/mach-omap2/sleep34xx.S
arch/arm/mach-omap2/sleep43xx.S
arch/arm/mach-omap2/sleep44xx.S
arch/arm/mach-tango/Makefile
arch/arm/mach-tango/smc.S