powerpc/boot: Disable vector instructions

[ Upstream commit e8e132e6885962582784b6fa16a80d07ea739c0f ]

This will avoid auto-vectorisation when building with higher
optimisation levels.

We don't know if the machine can support VSX and even if it's present
it's probably not going to be enabled at this point in boot.

These flag were both added prior to GCC 4.6 which is the minimum
compiler version supported by upstream, thanks to Segher for the
details.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index e2a5a932c24a84ae2dc337a3bd359617556d9448..5807c9d8e56d5bb26e02cae50cdc29a55595bc22 100644 (file)
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -24,8 +24,8 @@ compress-$(CONFIG_KERNEL_GZIP) := CONFIG_KERNEL_GZIP
 compress-$(CONFIG_KERNEL_XZ)   := CONFIG_KERNEL_XZ
 
 BOOTCFLAGS    := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
-                -fno-strict-aliasing -Os -msoft-float -pipe \
-                -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
+                -fno-strict-aliasing -Os -msoft-float -mno-altivec -mno-vsx \
+                -pipe -fomit-frame-pointer -fno-builtin -fPIC -nostdinc \
                 -D$(compress-y)
 
 BOOTCC := $(CC)