Commit 3fe1ee40 authored by Stefan Agner's avatar Stefan Agner Committed by Olof Johansson
Browse files

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: default avatarStefan Agner <stefan@agner.ch>
Acked-by: default avatarMans Rullgard <mans@mansr.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent 24cb4bc8
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+0 −3
Original line number Diff line number Diff line
@@ -40,9 +40,6 @@ obj-$(CONFIG_ARCH_BCM_MOBILE_L2_CACHE) += kona_l2_cache.o

# Support for secure monitor traps
obj-$(CONFIG_ARCH_BCM_MOBILE_SMC) += bcm_kona_smc.o
ifeq ($(call as-instr,.arch_extension sec,as_has_sec),as_has_sec)
CFLAGS_bcm_kona_smc.o		+= -Wa,-march=armv7-a+sec -DREQUIRES_SEC
endif

# BCM2835
obj-$(CONFIG_ARCH_BCM2835)	+= board_bcm2835.o
+0 −2
Original line number Diff line number Diff line
@@ -125,9 +125,7 @@ static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
		__asmeq("%2", "r4")
		__asmeq("%3", "r5")
		__asmeq("%4", "r6")
#ifdef REQUIRES_SEC
		".arch_extension sec\n"
#endif
		"	smc    #0\n"
		: "=r" (ip), "=r" (r0)
		: "r" (r4), "r" (r5), "r" (r6)
+0 −4
Original line number Diff line number Diff line
@@ -14,9 +14,5 @@ obj-$(CONFIG_PM_SLEEP) += suspend.o

obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o

plus_sec := $(call as-instr,.arch_extension sec,+sec)
AFLAGS_exynos-smc.o		:=-Wa,-march=armv7-a$(plus_sec)
AFLAGS_sleep.o			:=-Wa,-march=armv7-a$(plus_sec)

obj-$(CONFIG_MCPM)		+= mcpm-exynos.o
CFLAGS_mcpm-exynos.o		+= -march=armv7-a
+2 −1
Original line number Diff line number Diff line
@@ -10,7 +10,8 @@
/*
 * 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
+2 −1
Original line number Diff line number Diff line
@@ -44,7 +44,8 @@ ENTRY(exynos_cpu_resume)
ENDPROC(exynos_cpu_resume)

	.align

	.arch armv7-a
	.arch_extension sec
ENTRY(exynos_cpu_resume_ns)
	mrc	p15, 0, r0, c0, c0, 0
	ldr	r1, =CPU_MASK
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