linux-next/arch/arm/mach-exynos/exynos-smc.S
Stefan Agner 3fe1ee40b2 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>
2019-06-19 09:44:25 -07:00

21 lines
412 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2012 Samsung Electronics.
*
* Copied from omap-smc.S Copyright (C) 2010 Texas Instruments, Inc.
*/
#include <linux/linkage.h>
/*
* Function signature: void exynos_smc(u32 cmd, u32 arg1, u32 arg2, u32 arg3)
*/
.arch armv7-a
.arch_extension sec
ENTRY(exynos_smc)
stmfd sp!, {r4-r11, lr}
dsb
smc #0
ldmfd sp!, {r4-r11, pc}
ENDPROC(exynos_smc)