powerpc/boot: Disable vector instructions

BugLink: https://bugs.launchpad.net/bugs/1854975
[ 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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index 1925bbbb0b619dc96306730bcb52e0ccd50864d4..cf77c9e77e415b92dda0a40d1772c0acdb90824a 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)