linux5.2: build ppc64 BE with ELFv2

This commit is contained in:
q66 2019-07-12 19:37:24 +02:00 committed by Jürgen Buchmüller
parent 75cb5189f1
commit 2a9e619b99
2 changed files with 84 additions and 28 deletions

View file

@ -0,0 +1,84 @@
This makes the Linux kernel build as ELFv2 on big endian ppc64. The upstream
doesn't seem to be interested in this but it's a small patch that is unlikely
to break/easy to remake and in worst case can always be ditched.
Using ELFv2 has some potential performance benefits and is already always used
on little endian. It requires a relatively modern toolchain, which we already
have.
Ping q66 if it does not apply.
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -93,10 +93,8 @@ MULTIPLEWORD := -mmultiple
endif
ifdef CONFIG_PPC64
-cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
-cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mcall-aixdesc)
-aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
-aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mabi=elfv2
+cflags-y += $(call cc-option,-mabi=elfv2,$(call cc-option,-mcall-aixdesc))
+aflags-y += $(call cc-option,-mabi=elfv2,$(call cc-option,-mabi=elfv1))
endif
ifndef CONFIG_CC_IS_CLANG
@@ -144,14 +142,8 @@ endif
endif
CFLAGS-$(CONFIG_PPC64) := $(call cc-option,-mtraceback=no)
-ifdef CONFIG_CPU_LITTLE_ENDIAN
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2,$(call cc-option,-mcall-aixdesc))
-AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2)
-else
-CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
-CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcall-aixdesc)
-AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
-endif
+AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2,$(call cc-option,-mabi=elfv1))
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc))
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mno-pointers-to-nested-functions)
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -48,8 +48,8 @@ ifdef CONFIG_CPU_BIG_ENDIAN
BOOTCFLAGS += -mbig-endian
else
BOOTCFLAGS += -mlittle-endian
-BOOTCFLAGS += $(call cc-option,-mabi=elfv2)
endif
+BOOTCFLAGS += $(call cc-option,-mabi=elfv2)
BOOTAFLAGS := -D__ASSEMBLY__ $(BOOTCFLAGS) -traditional -nostdinc
--- a/drivers/crypto/vmx/Makefile
+++ b/drivers/crypto/vmx/Makefile
@@ -5,7 +5,7 @@ vmx-crypto-objs := vmx.o aesp8-ppc.o ghashp8-ppc.o aes.o aes_cbc.o aes_ctr.o aes
ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
TARGET := linux-ppc64le
else
-TARGET := linux-ppc64
+TARGET := linux-ppc64v2
endif
quiet_cmd_perl = PERL $@
--- a/drivers/crypto/vmx/ppc-xlate.pl
+++ b/drivers/crypto/vmx/ppc-xlate.pl
@@ -40,7 +40,7 @@ my $globl = sub {
};
my $text = sub {
my $ret = ($flavour =~ /aix/) ? ".csect\t.text[PR],7" : ".text";
- $ret = ".abiversion 2\n".$ret if ($flavour =~ /linux.*64le/);
+ $ret = ".abiversion 2\n".$ret if ($flavour =~ /linux.*64(le|v2)/);
$ret;
};
my $machine = sub {
@@ -142,7 +142,7 @@ my $vmr = sub {
# Some ABIs specify vrsave, special-purpose register #256, as reserved
# for system use.
-my $no_vrsave = ($flavour =~ /linux-ppc64le/);
+my $no_vrsave = ($flavour =~ /linux-ppc64(le|v2)/);
my $mtspr = sub {
my ($f,$idx,$ra) = @_;
if ($idx == 256 && $no_vrsave) {

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@ -1,28 +0,0 @@
Since gcc 9.1, adding `-mcall-aixdesc` to cflags makes it no longer define
`__linux__`, which breaks compilation of the kernel in places where the macro
is checked (which is multiple). This behavior is actually more correct than
it was before, as `-mcall-aixdesc` is only meant to be used when compiling
for AIX.
However, it is not enough to just drop it and use `-mabi=elfv1`, as that
results in a ton of undefined references all over the place when linking.
So work around it until upstream sorts it out.
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -96,6 +96,7 @@ endif
ifdef CONFIG_PPC64
cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
cflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mcall-aixdesc)
+cflags-$(CONFIG_CPU_BIG_ENDIAN) += -D__linux__
aflags-$(CONFIG_CPU_BIG_ENDIAN) += $(call cc-option,-mabi=elfv1)
aflags-$(CONFIG_CPU_LITTLE_ENDIAN) += -mabi=elfv2
endif
@@ -151,6 +152,7 @@ AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv2)
else
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcall-aixdesc)
+CFLAGS-$(CONFIG_PPC64) += -D__linux__
AFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mabi=elfv1)
endif
CFLAGS-$(CONFIG_PPC64) += $(call cc-option,-mcmodel=medium,$(call cc-option,-mminimal-toc))