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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-04-08 12:17:49 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-04-20 12:54:22 +1000 |
| commit | dc5dac748af9087e9240bd2ae6ae7db48d5360ae (patch) | |
| tree | 59998f55199668c054226f3bc29fc4963fc35741 /arch/powerpc/Makefile | |
| parent | b270bebd34e36fb69363d65e24b00a9d148903e8 (diff) | |
| download | linux-dc5dac748af9087e9240bd2ae6ae7db48d5360ae.tar.gz linux-dc5dac748af9087e9240bd2ae6ae7db48d5360ae.tar.bz2 linux-dc5dac748af9087e9240bd2ae6ae7db48d5360ae.zip | |
powerpc/64: Add support to build with prefixed instructions
Add an option to build kernel and module with prefixed instructions if
the CPU and toolchain support it.
This is not related to kernel support for userspace execution of
prefixed instructions.
Building with prefixed instructions breaks some extended inline asm
memory addressing, for example it will provide immediates that exceed
the range of simple load/store displacement. Whether this is a
toolchain or a kernel asm problem remains to be seen. For now, these
are replaced with simpler and less efficient direct register addressing
when compiling with prefixed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230408021752.862660-4-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/Makefile')
| -rw-r--r-- | arch/powerpc/Makefile | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 4343cca57cb3..9fb770d3b409 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -180,7 +180,11 @@ ifdef CONFIG_476FPE_ERR46 endif # No prefix or pcrel +ifdef CONFIG_PPC_KERNEL_PREFIXED +KBUILD_CFLAGS += $(call cc-option,-mprefixed) +else KBUILD_CFLAGS += $(call cc-option,-mno-prefixed) +endif KBUILD_CFLAGS += $(call cc-option,-mno-pcrel) # No AltiVec or VSX or MMA instructions when building kernel |