powerpc/book3s64: Always build for power4 or later

When we're not compiling for a specific CPU, ie. none of the
CONFIG_POWERx_CPU options are set, and CONFIG_GENERIC_CPU *is* set, we
currently don't pass any -mcpu option to the compiler. This means the
compiler builds for a "generic" Power CPU.

But back in 2014 we dropped support for pre power4 CPUs in commit
468a33028e ("powerpc: Drop support for pre-POWER4 cpus").

Given that, there's no point in building the kernel to run on pre power4
cpus. So update the flags we pass to the compiler when
CONFIG_GENERIC_CPU is set, to specify -mcpu=power4.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Michael Ellerman 2016-10-20 16:00:14 +11:00
parent 70839d2077
commit 3a849815a1

View File

@ -121,6 +121,7 @@ CFLAGS-$(CONFIG_PPC32) := -ffixed-r2 $(MULTIPLEWORD)
ifeq ($(CONFIG_PPC_BOOK3S_64),y)
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,-mtune=power4)
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power4
else
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
endif