powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS

The powerpc toolchain can compile combinations of 32/64 bit and
big/little endian, so it's convenient to consider, e.g.,

  `CC -m64 -mbig-endian`

To be the C compiler for the purpose of invoking it to build target
artifacts. So overriding the CC variable to include these flags works
for this purpose.

Unfortunately that is not compatible with the way the proposed new
Kconfig macro language will work.

After previous patches in this series, these flags can be carefully
passed in using flags instead.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Nicholas Piggin 2018-05-30 22:19:21 +10:00 committed by Michael Ellerman
parent af3901cbbd
commit 1421dc6d48
3 changed files with 34 additions and 12 deletions

View File

@ -75,13 +75,15 @@ endif
endif
ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
override LD += -EL
KBUILD_CFLAGS += -mlittle-endian
LDFLAGS += -EL
LDEMULATION := lppc
GNUTARGET := powerpcle
MULTIPLEWORD := -mno-multiple
KBUILD_CFLAGS_MODULE += $(call cc-option,-mno-save-toc-indirect)
else
override LD += -EB
KBUILD_CFLAGS += $(call cc-option,-mbig-endian)
LDFLAGS += -EB
LDEMULATION := ppc
GNUTARGET := powerpc
MULTIPLEWORD := -mmultiple
@ -94,19 +96,19 @@ aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mabi=elfv2
endif
cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian)
ifneq ($(cc-name),clang)
cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mno-strict-align
endif
cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian)
cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mbig-endian)
aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mlittle-endian
ifeq ($(HAS_BIARCH),y)
override AS += -a$(BITS)
override LD += -m elf$(BITS)$(LDEMULATION)
override CC += -m$(BITS)
KBUILD_CFLAGS += -m$(BITS)
KBUILD_AFLAGS += -m$(BITS) -Wl,-a$(BITS)
LDFLAGS += -m elf$(BITS)$(LDEMULATION)
KBUILD_ARFLAGS += --target=elf$(BITS)-$(GNUTARGET)
endif

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@ -7,17 +7,21 @@ set -o pipefail
# To debug, uncomment the following line
# set -x
# -mprofile-kernel is only supported on 64le, so this should not be invoked
# for other targets. Therefore we can pass in -m64 and -mlittle-endian
# explicitly, to take care of toolchains defaulting to other targets.
# Test whether the compile option -mprofile-kernel exists and generates
# profiling code (ie. a call to _mcount()).
echo "int func() { return 0; }" | \
$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
grep -q "_mcount"
$* -m64 -mlittle-endian -S -x c -O2 -p -mprofile-kernel - -o - \
2> /dev/null | grep -q "_mcount"
# Test whether the notrace attribute correctly suppresses calls to _mcount().
echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" | \
$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
grep -q "_mcount" && \
$* -m64 -mlittle-endian -S -x c -O2 -p -mprofile-kernel - -o - \
2> /dev/null | grep -q "_mcount" && \
exit 1
echo "OK"

View File

@ -266,13 +266,29 @@ if ($arch eq "x86_64") {
$objcopy .= " -O elf32-sh-linux";
} elsif ($arch eq "powerpc") {
my $ldemulation;
$local_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
# See comment in the sparc64 section for why we use '\w'.
$function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?\\w*?)>:";
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";
if ($endian eq "big") {
$cc .= " -mbig-endian ";
$ld .= " -EB ";
$ldemulation = "ppc"
} else {
$cc .= " -mlittle-endian ";
$ld .= " -EL ";
$ldemulation = "lppc"
}
if ($bits == 64) {
$type = ".quad";
$cc .= " -m64 ";
$ld .= " -m elf64".$ldemulation." ";
} else {
$cc .= " -m32 ";
$ld .= " -m elf32".$ldemulation." ";
}
} elsif ($arch eq "arm") {