From: Ben Hutchings <ben@decadent.org.uk>
Date: Wed, 26 Dec 2018 00:00:40 +0000
Subject: powerpc: Fix -mcpu= options for SPE-only compiler
Forwarded: https://lists.debian.org/debian-kernel/2018/12/msg00295.html

GCC for Debian's "powerpcspe" architecture only supports 32-bit
SPE targets, and using -mcpu=powerpc or -mcpu=powerpc64 is a fatal
error.

* Change the test for a biarch compiler to pass both the -m32 and -m64
  options, so that it doesn't catch 32-bit-only compilers
* Add an ifdef CONFIG_PPC64 around the 64-bit CPU option definitions

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -12,7 +12,7 @@
 # Rewritten by Cort Dougan and Paul Mackerras
 #
 
-HAS_BIARCH	:= $(call cc-option-yn, -m32)
+HAS_BIARCH	:= $(call cc-option-yn, -m32 -m64)
 
 # Set default 32 bits cross compilers for vdso and boot wrapper
 CROSS32_COMPILE ?=
@@ -155,6 +155,7 @@
 
 CFLAGS-$(CONFIG_PPC32)	+= $(call cc-option,-mno-readonly-in-sdata)
 
+ifdef CONFIG_PPC64
 ifdef CONFIG_PPC_BOOK3S_64
 ifdef CONFIG_CPU_LITTLE_ENDIAN
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8
@@ -166,6 +167,7 @@
 else
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
 endif
+endif
 
 ifdef CONFIG_FUNCTION_TRACER
 CC_FLAGS_FTRACE := -pg