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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-04-08 05:17:49 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-04-20 05:54:22 +0300 |
| commit | dc5dac748af9087e9240bd2ae6ae7db48d5360ae (patch) | |
| tree | 59998f55199668c054226f3bc29fc4963fc35741 /arch/powerpc/kernel/trace/ftrace.c | |
| parent | b270bebd34e36fb69363d65e24b00a9d148903e8 (diff) | |
| download | linux-dc5dac748af9087e9240bd2ae6ae7db48d5360ae.tar.xz | |
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/kernel/trace/ftrace.c')
| -rw-r--r-- | arch/powerpc/kernel/trace/ftrace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 7b85c3b460a3..72864fb7a6cc 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -194,6 +194,8 @@ __ftrace_make_nop(struct module *mod, * get corrupted. * * Use a b +8 to jump over the load. + * XXX: could make PCREL depend on MPROFILE_KERNEL + * XXX: check PCREL && MPROFILE_KERNEL calling sequence */ if (IS_ENABLED(CONFIG_MPROFILE_KERNEL) || IS_ENABLED(CONFIG_PPC32)) pop = ppc_inst(PPC_RAW_NOP()); |