evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

ARC: Explicitly add -mmedium-calls to CFLAGS

Browse source 
[ Upstream commit 74c11e300c103af47db5b658fdcf28002421e250 ]

GCC built for arc*-*-linux has "-mmedium-calls" implicitly enabled by default
thus we don't see any problems during Linux kernel compilation.
----------------------------->8------------------------
arc-linux-gcc -mcpu=arc700 -Q --help=target | grep calls
  -mlong-calls                          [disabled]
  -mmedium-calls                        [enabled]
----------------------------->8------------------------

But if we try to use so-called Elf32 toolchain with GCC configured for
arc*-*-elf* then we'd see the following failure:
----------------------------->8------------------------
init/do_mounts.o: In function 'init_rootfs':
do_mounts.c:(.init.text+0x108): relocation truncated to fit: R_ARC_S21W_PCREL
against symbol 'unregister_filesystem' defined in .text section in fs/filesystems.o

arc-elf32-ld: final link failed: Symbol needs debug section which does not exist
make: *** [vmlinux] Error 1
----------------------------->8------------------------

That happens because neither "-mmedium-calls" nor "-mlong-calls" are enabled in
Elf32 GCC:
----------------------------->8------------------------
arc-elf32-gcc -mcpu=arc700 -Q --help=target | grep calls
  -mlong-calls                          [disabled]
  -mmedium-calls                        [disabled]
----------------------------->8------------------------

Now to make it possible to use Elf32 toolchain for building Linux kernel
we're explicitly add "-mmedium-calls" to CFLAGS.

And since we add "-mmedium-calls" to the global CFLAGS there's no point in
having per-file copies thus removing them.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexey Brodkin 2018-06-01 14:34:33 +03:00 • committed by Greg Kroah-Hartman
parent 78f654f6cc
commit 97aaf73394
1 changed files with 1 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
arch/arc/Makefile
View file

@ -14,7 +14,7 @@ endif
KBUILD_DEFCONFIG := nsim_700_defconfig
cflags-y += -fno-common -pipe -fno-builtin -D__linux__
cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7
cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs
@ -137,16 +137,3 @@ dtbs: scripts
archclean:
$(Q)$(MAKE) $(clean)=$(boot)
# Hacks to enable final link due to absence of link-time branch relexation
# and gcc choosing optimal(shorter) branches at -O3
#
# vineetg Feb 2010: -mlong-calls switched off for overall kernel build
# However lib/decompress_inflate.o (.init.text) calls
# zlib_inflate_workspacesize (.text) causing relocation errors.
# Thus forcing all exten calls in this file to be long calls
export CFLAGS_decompress_inflate.o = -mmedium-calls
export CFLAGS_initramfs.o = -mmedium-calls
ifdef CONFIG_SMP
export CFLAGS_core.o = -mmedium-calls
endif