linux/arch/arm/mach-at91/Makefile
Nick Desaulniers a2faac3986 ARM: 9263/1: use .arch directives instead of assembler command line flags
Similar to commit a6c30873ee ("ARM: 8989/1: use .fpu assembler
directives instead of assembler arguments").

GCC and GNU binutils support setting the "sub arch" via -march=,
-Wa,-march, target function attribute, and .arch assembler directive.

Clang was missing support for -Wa,-march=, but this was implemented in
clang-13.

The behavior of both GCC and Clang is to
prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
sources, but Clang will warn about the -march= being unused.

clang: warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

Since most assembler is non-conditionally assembled with one sub arch
(modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
.arch assembler directive.

Add a few more instances found in compile testing as found by Arnd and
Nathan.

Link: 1d51c699b9
Link: https://bugs.llvm.org/show_bug.cgi?id=48894
Link: https://github.com/ClangBuiltLinux/linux/issues/1195
Link: https://github.com/ClangBuiltLinux/linux/issues/1315

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
2022-11-08 18:36:17 +00:00

27 lines
680 B
Makefile

# SPDX-License-Identifier: GPL-2.0
#
# Makefile for the linux kernel.
#
# CPU-specific support
obj-$(CONFIG_SOC_AT91RM9200) += at91rm9200.o
obj-$(CONFIG_SOC_AT91SAM9) += at91sam9.o
obj-$(CONFIG_SOC_SAM9X60) += sam9x60.o
obj-$(CONFIG_SOC_SAMA5) += sama5.o sam_secure.o
obj-$(CONFIG_SOC_SAMA7) += sama7.o
obj-$(CONFIG_SOC_SAMV7) += samv7.o
# Power Management
obj-$(CONFIG_ATMEL_PM) += pm.o pm_suspend.o
ifeq ($(CONFIG_PM_DEBUG),y)
CFLAGS_pm.o += -DDEBUG
endif
$(obj)/pm_data-offsets.h: $(obj)/pm_data-offsets.s FORCE
$(call filechk,offsets,__PM_DATA_OFFSETS_H__)
$(obj)/pm_suspend.o: $(obj)/pm_data-offsets.h
targets += pm_data-offsets.s
clean-files += pm_data-offsets.h