cc-option-yn can be replaced with cc-option. ie.
Checking for support:
ifeq ($(call cc-option-yn,$(FLAG)),y)
becomes:
ifneq ($(call cc-option,$(FLAG)),)

Checking for lack of support:
ifeq ($(call cc-option-yn,$(FLAG)),n)
becomes:
ifeq ($(call cc-option,$(FLAG)),)

This allows us to pursue removing cc-option-yn.

Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <redacted>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Nick Desaulniers <redacted>
---
  arch/powerpc/Makefile      | 12 ++++++------
  arch/powerpc/boot/Makefile |  5 +----
  2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 9aaf1abbc641..85e224536cf7 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -12,12 +12,12 @@
  # Rewritten by Cort Dougan and Paul Mackerras
  #
  
-HAS_BIARCH	:= $(call cc-option-yn, -m32)
+HAS_BIARCH	:= $(call cc-option,-m32)
  
  # Set default 32 bits cross compilers for vdso and boot wrapper
  CROSS32_COMPILE ?=
  
-ifeq ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
  ifeq ($(CROSS32_COMPILE),)
  ifdef CONFIG_PPC32
  # These options will be overridden by any -mcpu option that the CPU

@@ -107,7 +107,7 @@ 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 ($(HAS_BIARCH),y)
+ifeq ($(HAS_BIARCH),-m32)
  KBUILD_CFLAGS	+= -m$(BITS)
  KBUILD_AFLAGS	+= -m$(BITS) -Wl,-a$(BITS)
  KBUILD_LDFLAGS	+= -m elf$(BITS)$(LDEMULATION)

@@ -125,7 +125,9 @@ LDFLAGS_vmlinux-$(CONFIG_RELOCATABLE) := -pie
  LDFLAGS_vmlinux	:= $(LDFLAGS_vmlinux-y)
  
  ifdef CONFIG_PPC64
-ifeq ($(call cc-option-yn,-mcmodel=medium),y)
+ifeq ($(call cc-option,-mcmodel=medium),)
+	export NO_MINIMAL_TOC := -mno-minimal-toc
+else
  	# -mcmodel=medium breaks modules because it uses 32bit offsets from
  	# the TOC pointer to create pointers where possible. Pointers into the
  	# percpu data area are created by this method.

@@ -135,8 +137,6 @@ ifeq ($(call cc-option-yn,-mcmodel=medium),y)
  	# kernel percpu data space (starting with 0xc...). We need a full
  	# 64bit relocation for this to work, hence -mcmodel=large.
  	KBUILD_CFLAGS_MODULE += -mcmodel=large
-else
-	export NO_MINIMAL_TOC := -mno-minimal-toc
  endif
  endif
  

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 10c0fb306f15..33e1de5d1c95 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile

@@ -66,10 +66,7 @@ ifdef CONFIG_DEBUG_INFO
  BOOTCFLAGS	+= -g
  endif
  
-ifeq ($(call cc-option-yn, -fstack-protector),y)
-BOOTCFLAGS	+= -fno-stack-protector
-endif
-
+BOOTCFLAGS	+= $(call cc-option,-fstack-protector)