powerpc/64s: POWER10 CPU Kconfig build option

This adds basic POWER10_CPU option, which builds with -mcpu=power10.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220923033004.536127-1-npiggin@gmail.com

arch/powerpc/Makefile

@@ -192,9 +192,14 @@ ifdef CONFIG_476FPE_ERR46
 		-T $(srctree)/arch/powerpc/platforms/44x/ppc476_modules.lds
 endif
 
-# No AltiVec or VSX instructions when building kernel
+# No prefix or pcrel
+KBUILD_CFLAGS += $(call cc-option,-mno-prefixed)
+KBUILD_CFLAGS += $(call cc-option,-mno-pcrel)
+
+# No AltiVec or VSX or MMA instructions when building kernel
 KBUILD_CFLAGS += $(call cc-option,-mno-altivec)
 KBUILD_CFLAGS += $(call cc-option,-mno-vsx)
+KBUILD_CFLAGS += $(call cc-option,-mno-mma)
 
 # No SPE instruction when building kernel
 # (We use all available options to help semi-broken compilers)

arch/powerpc/platforms/Kconfig.cputype

@@ -172,6 +172,11 @@ config POWER9_CPU
 	depends on PPC_BOOK3S_64
 	select ARCH_HAS_FAST_MULTIPLIER
 
+config POWER10_CPU
+	bool "POWER10"
+	depends on PPC_BOOK3S_64
+	select ARCH_HAS_FAST_MULTIPLIER
+
 config E5500_CPU
 	bool "Freescale e5500"
 	depends on PPC64 && PPC_E500
@@ -240,6 +245,7 @@ config TARGET_CPU
 	default "power7" if POWER7_CPU
 	default "power8" if POWER8_CPU
 	default "power9" if POWER9_CPU
+	default "power10" if POWER10_CPU
 	default "405" if 405_CPU
 	default "440" if 440_CPU
 	default "464" if 464_CPU