This series implements inline static calls on PPC32.
First patch adds to static_call core the ability to pass the
trampoline address at the same time as the site address to
arch_static_call_transform() so that it can fallback on branching to
the trampoline when the site is too far (Max distance for direct
branch is 32 Mbytes on powerpc).
Second patch adds support for decoding all types of uncond branches.
Third patch rearranges function arch_static_call_transform() to ease
implementation of inline static call in following patch.
Last patch implements inline static calls on PPC32: This is done by:
- Put a 'bl' to the destination function ('b' if tail call)
- Put a 'nop' when the destination function is NULL ('blr' if tail call)
- Put a 'li r3,0' when the destination is the RET0 function and not
a tail call.
If the destination is too far (over the 32Mb limit), go via the
trampoline thanks to patch 1.
Christophe Leroy (4):
static_call_inline: Provide trampoline address when updating sites
objtool/powerpc: Add support for decoding all types of uncond branches
powerpc: Prepare arch_static_call_transform() for supporting inline
static calls
powerpc/static_call: Implement inline static calls
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/static_call.h | 2 +
arch/powerpc/kernel/static_call.c | 58 +++++++++++++++++++-------
arch/x86/kernel/static_call.c | 2 +-
kernel/static_call_inline.c | 2 +-
tools/objtool/arch/powerpc/decode.c | 8 +++-
6 files changed, 55 insertions(+), 18 deletions(-)
--
2.47.0
