[PATCH 4.4 111/162] ARM: 9156/1: drop cc-option fallbacks for architecture selection

Greg Kroah-Hartman
2021-11-24T12:08:25Z

From: Arnd Bergmann <arnd@arndb.de>

commit 418ace9992a7647c446ed3186df40cf165b67298 upstream.

Naresh and Antonio ran into a build failure with latest Debian
armhf compilers, with lots of output like

tmp/ccY3nOAs.s:2215: Error: selected processor does not support `cpsid i' in ARM mode

As it turns out, $(cc-option) fails early here when the FPU is not
selected before CPU architecture is selected, as the compiler
option check runs before enabling -msoft-float, which causes
a problem when testing a target architecture level without an FPU:

cc1: error: '-mfloat-abi=hard': selected architecture lacks an FPU

Passing e.g. -march=armv6k+fp in place of -march=armv6k would avoid this
issue, but the fallback logic is already broken because all supported
compilers (gcc-5 and higher) are much more recent than these options,
and building with -march=armv5t as a fallback no longer works.

The best way forward that I see is to just remove all the checks, which
also has the nice side-effect of slightly improving the startup time for
'make'.

The -mtune=marvell-f option was apparently never supported by any mainline
compiler, and the custom Codesourcery gcc build that did support is
now too old to build kernels, so just use -mtune=xscale unconditionally
for those.

This should be safe to apply on all stable kernels, and will be required
in order to keep building them with gcc-11 and higher.

Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=996419

Reported-by: Antonio Terceiro <antonio.terceiro@linaro.org>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Tested-by: Klaus Kudielka <klaus.kudielka@gmail.com>
Cc: Matthias Klose <doko@debian.org>
Cc: stable@vger.kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm/Makefile | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -66,15 +66,15 @@ KBUILD_CFLAGS += $(call cc-option,-fno-i
# Note that GCC does not numerically define an architecture version
# macro, but instead defines a whole series of macros which makes
# testing for a specific architecture or later rather impossible.
-arch-$(CONFIG_CPU_32v7M) =-D__LINUX_ARM_ARCH__=7 -march=armv7-m -Wa,-march=armv7-m
-arch-$(CONFIG_CPU_32v7) =-D__LINUX_ARM_ARCH__=7 $(call cc-option,-march=armv7-a,-march=armv5t -Wa$(comma)-march=armv7-a)
-arch-$(CONFIG_CPU_32v6) =-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6,-march=armv5t -Wa$(comma)-march=armv6)
+arch-$(CONFIG_CPU_32v7M) =-D__LINUX_ARM_ARCH__=7 -march=armv7-m
+arch-$(CONFIG_CPU_32v7) =-D__LINUX_ARM_ARCH__=7 -march=armv7-a
+arch-$(CONFIG_CPU_32v6) =-D__LINUX_ARM_ARCH__=6 -march=armv6
# Only override the compiler option if ARMv6. The ARMv6K extensions are
# always available in ARMv7
ifeq ($(CONFIG_CPU_32v6),y)
-arch-$(CONFIG_CPU_32v6K) =-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6k,-march=armv5t -Wa$(comma)-march=armv6k)
+arch-$(CONFIG_CPU_32v6K) =-D__LINUX_ARM_ARCH__=6 -march=armv6k
endif
-arch-$(CONFIG_CPU_32v5) =-D__LINUX_ARM_ARCH__=5 $(call cc-option,-march=armv5te,-march=armv4t)
+arch-$(CONFIG_CPU_32v5) =-D__LINUX_ARM_ARCH__=5 -march=armv5te
arch-$(CONFIG_CPU_32v4T) =-D__LINUX_ARM_ARCH__=4 -march=armv4t
arch-$(CONFIG_CPU_32v4) =-D__LINUX_ARM_ARCH__=4 -march=armv4
arch-$(CONFIG_CPU_32v3) =-D__LINUX_ARM_ARCH__=3 -march=armv3
@@ -88,7 +88,7 @@ tune-$(CONFIG_CPU_ARM720T) =-mtune=arm7t
tune-$(CONFIG_CPU_ARM740T) =-mtune=arm7tdmi
tune-$(CONFIG_CPU_ARM9TDMI) =-mtune=arm9tdmi
tune-$(CONFIG_CPU_ARM940T) =-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM946E) =$(call cc-option,-mtune=arm9e,-mtune=arm9tdmi)
+tune-$(CONFIG_CPU_ARM946E) =-mtune=arm9e
tune-$(CONFIG_CPU_ARM920T) =-mtune=arm9tdmi
tune-$(CONFIG_CPU_ARM922T) =-mtune=arm9tdmi
tune-$(CONFIG_CPU_ARM925T) =-mtune=arm9tdmi
@@ -96,11 +96,11 @@ tune-$(CONFIG_CPU_ARM926T) =-mtune=arm9t
tune-$(CONFIG_CPU_FA526) =-mtune=arm9tdmi
tune-$(CONFIG_CPU_SA110) =-mtune=strongarm110
tune-$(CONFIG_CPU_SA1100) =-mtune=strongarm1100
-tune-$(CONFIG_CPU_XSCALE) =$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale
-tune-$(CONFIG_CPU_XSC3) =$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale
-tune-$(CONFIG_CPU_FEROCEON) =$(call cc-option,-mtune=marvell-f,-mtune=xscale)
-tune-$(CONFIG_CPU_V6) =$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)
-tune-$(CONFIG_CPU_V6K) =$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)
+tune-$(CONFIG_CPU_XSCALE) =-mtune=xscale
+tune-$(CONFIG_CPU_XSC3) =-mtune=xscale
+tune-$(CONFIG_CPU_FEROCEON) =-mtune=xscale
+tune-$(CONFIG_CPU_V6) =-mtune=arm1136j-s
+tune-$(CONFIG_CPU_V6K) =-mtune=arm1136j-s

# Evaluate tune cc-option calls now
tune-y := $(tune-y)