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	2020-01-05 14:40:50.395763093 +0100
+++ b/arch/powerpc/Makefile	2020-01-05 14:48:39.025251092 +0100
@@ -92,10 +92,8 @@
 
 ifdef CONFIG_PPC64
 ifndef CONFIG_CC_IS_CLANG
-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
 endif
 
@@ -144,14 +142,8 @@
 
 CFLAGS-$(CONFIG_PPC64)	:= $(call cc-option,-mtraceback=no)
 ifndef CONFIG_CC_IS_CLANG
-ifdef CONFIG_CPU_LITTLE_ENDIAN
 CFLAGS-$(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))
 endif
 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	2020-01-01 10:56:10.560965046 +0100
+++ b/drivers/crypto/vmx/Makefile	2020-01-01 10:57:05.189968856 +0100
@@ -5,7 +5,7 @@
 ifeq ($(CONFIG_CPU_LITTLE_ENDIAN),y)
 override flavour := linux-ppc64le
 else
-override flavour := linux-ppc64
+override flavour := 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) {