Christophe Leroy [off-list ref] writes:

Le 11/12/2022 à 18:32, Pali Rohár a écrit :

quoted

On Monday 11 July 2022 16:19:33 Christophe Leroy wrote:

quoted

With GCC 12, corenet64_smp_defconfig leads to the following build errors:

   CC      arch/powerpc/kernel/irq.o
{standard input}: Assembler messages:
{standard input}:3616: Error: unrecognized opcode: `wrteei'
{standard input}:5689: Error: unrecognized opcode: `wrteei'
   CC      arch/powerpc/kernel/pmc.o
{standard input}: Assembler messages:
{standard input}:42: Error: unrecognized opcode: `mfpmr'
{standard input}:53: Error: unrecognized opcode: `mtpmr'
   CC      arch/powerpc/kernel/io.o
{standard input}: Assembler messages:
{standard input}:376: Error: unrecognized opcode: `mbar'
...
   CC      arch/powerpc/mm/nohash/book3e_hugetlbpage.o
{standard input}: Assembler messages:
{standard input}:291: Error: unrecognized opcode: `tlbsx'
{standard input}:482: Error: unrecognized opcode: `tlbwe'
{standard input}:608: Error: unrecognized opcode: `lbarx'
{standard input}:608: Error: unrecognized opcode: `stbcx.'

-mpcu=powerpc64 cannot be used anymore for book3e, it must be a booke CPU.

But then we get:

   CC      arch/powerpc/lib/xor_vmx.o
cc1: error: AltiVec not supported in this target

Altivec is not supported with -mcpu=e5500 so don't allow selection
of altivec when e5500 is selected.

Signed-off-by: Christophe Leroy <redacted>
---
  arch/powerpc/Makefile                  | 8 +-------
  arch/powerpc/platforms/Kconfig.cputype | 8 ++++----
  2 files changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index d54e1fe03551..02742facf895 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile

@@ -168,13 +168,7 @@ endif
  CFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU))
  AFLAGS-$(CONFIG_TARGET_CPU_BOOL) += $(call cc-option,-mcpu=$(CONFIG_TARGET_CPU))
  
-# Altivec option not allowed with e500mc64 in GCC.
-ifdef CONFIG_ALTIVEC
-E5500_CPU := -mcpu=powerpc64
-else
-E5500_CPU := $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
-endif
-CFLAGS-$(CONFIG_E5500_CPU) += $(E5500_CPU)
+CFLAGS-$(CONFIG_E5500_CPU) += $(call cc-option,-mcpu=e500mc64,-mcpu=powerpc64)
  CFLAGS-$(CONFIG_E6500_CPU) += $(call cc-option,-mcpu=e6500,$(E5500_CPU))

Hello! I think that there is an issue. After removal of E5500_CPU
variable few line above, it cannot be used in CFLAGS-$(CONFIG_E6500_CPU)
assignment, because it is empty.

Ah yes, you are right.

It should be fixed by 
https://github.com/linuxppc/linux/commit/f2636eaac7dee1d7d096cc115ff4f5111b0c508c

Michael, I see the patch is in next-test. Can you add:

Fixes: d6b551b8f90c ("powerpc/64e: Fix build failure with GCC 12 
(unrecognized opcode: `wrteei')")

Yep, will do.

cheers