[PATCH u-boot] powerpc/mpc85xx: Disable AltiVec and VSX instructions

[PATCH u-boot] powerpc/mpc85xx: Disable AltiVec and VSX instructions

[Pali Rohár]

All vector instructions on powerpc mpc85xx must not be used because U-Boot
does not enable them. Usage cause random crashes. SPE vector instructions
are already disabled by compiler flags, so disable also AltiVec and VSX
vector instructions.

Linux kernel disables AltiVec and VSX instructions too.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 arch/powerpc/cpu/mpc85xx/config.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/powerpc/cpu/mpc85xx/config.mk b/arch/powerpc/cpu/mpc85xx/config.mk
index 482bb90cb120..71a98f05c902 100644
--- a/arch/powerpc/cpu/mpc85xx/config.mk
+++ b/arch/powerpc/cpu/mpc85xx/config.mk
@@ -13,6 +13,10 @@ PLATFORM_RELFLAGS += -msingle-pic-base -fno-jump-tables
 PLATFORM_CPPFLAGS += $(call cc-option,-mno-spe) \
 		     $(call cc-option,-mspe=no)
 
+# No AltiVec or VSX instructions when building u-boot
+PLATFORM_CPPFLAGS += $(call cc-option,-mno-altivec)
+PLATFORM_CPPFLAGS += $(call cc-option,-mno-vsx)
+
 ifdef CONFIG_E6500
 PLATFORM_CPPFLAGS += -mcpu=e6500
 else ifdef CONFIG_E5500
-- 
2.20.1

Re: [PATCH u-boot] powerpc/mpc85xx: Disable AltiVec and VSX instructions

[Tom Rini]

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On Mon, Dec 19, 2022 at 10:46:22PM +0100, Pali Rohár wrote:

> All vector instructions on powerpc mpc85xx must not be used because U-Boot
> does not enable them. Usage cause random crashes. SPE vector instructions
> are already disabled by compiler flags, so disable also AltiVec and VSX
> vector instructions.
> 
> Linux kernel disables AltiVec and VSX instructions too.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>

Applied to u-boot/master, thanks!

-- 
Tom

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