On Fri, 4 Sep 2020 11:01:30 +0000 (UTC), Christophe Leroy wrote:

__put_user_asm_goto() provides more flexibility to GCC and avoids using
a local variable to tell if the write succeeded or not.
GCC can then avoid implementing a cmp in the fast path.

See the difference for a small function like the PPC64 version of
save_general_regs() in arch/powerpc/kernel/signal_32.c:

[...]

Applied to powerpc/next.

[1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()
      https://git.kernel.org/powerpc/c/ee0a49a6870ea75e25b4d4984c1bb6b3b7c65f2b
[2/3] powerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto()
      https://git.kernel.org/powerpc/c/e64ac41ab0c510b3f85199a585eb886cad92fb19
[3/3] powerpc/uaccess: Remove __put_user_asm() and __put_user_asm2()
      https://git.kernel.org/powerpc/c/7fdf966bed155b214f4f1f9b67825a40b2e9b998

cheers