This is a note to let you know that I've just added the patch titled
powerpc/64s: Fix GENERIC_CPU build flags for PPC970 / G5
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-64s-fix-generic_cpu-build-flags-for-ppc970-g.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 15a4becff3cc9c7a55ad178a2c4d8b0d90bbf10d
Author: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Wed Sep 21 11:41:02 2022 +1000
powerpc/64s: Fix GENERIC_CPU build flags for PPC970 / G5
[ Upstream commit 58ec7f06b74e0d6e76c4110afce367c8b5f0837d ]
Big-endian GENERIC_CPU supports 970, but builds with -mcpu=power5.
POWER5 is ISA v2.02 whereas 970 is v2.01 plus Altivec. 2.02 added
the popcntb instruction which a compiler might use.
Use -mcpu=power4.
Fixes: 471d7ff8b51b ("powerpc/64s: Remove POWER4 support")
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Reviewed-by: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220921014103.587954-1-npiggin@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 2bb0fe9b2058..7859ae56fcdc 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -154,7 +154,7 @@ CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power8
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power9,-mtune=power8)
else
CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=power7,$(call cc-option,-mtune=power5))
-CFLAGS-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mcpu=power5,-mcpu=power4)
+CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=power4
endif
else ifdef CONFIG_PPC_BOOK3E_64
CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
