When PPC_FPU is not set and ALTIVEC=y, arch/powerpc/lib/ldstfp.c is not being built, but it is also needed when ALTIVEC=y for get_vr() and put_vr().
../arch/powerpc/lib/sstep.c: In function 'do_vec_load': ../arch/powerpc/lib/sstep.c:637:3: error: implicit declaration of function 'put_vr' [-Werror=implicit-function-declaration] 637 | put_vr(rn, &u.v); | ^~~~~~ ../arch/powerpc/lib/sstep.c: In function 'do_vec_store': ../arch/powerpc/lib/sstep.c:660:3: error: implicit declaration of function 'get_vr'; did you mean 'get_oc'? [-Werror=implicit-function-declaration] 660 | get_vr(rn, &u.v); | ^~~~~~ Add ldstfp.o to the Makefile for CONFIG_ALTIVEC and add externs for get_vr() and put_vr() in lib/sstep.c to fix the build errors. This was seen in a kernel config from kernel test robot <l...@intel.com> that reported a different build issue (for pmac32-cpufreq.c). Signed-off-by: Randy Dunlap <rdun...@infradead.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Christophe Leroy <christophe.le...@csgroup.eu> Cc: Segher Boessenkool <seg...@kernel.crashing.org> Cc: l...@intel.com --- arch/powerpc/lib/Makefile | 1 + arch/powerpc/lib/sstep.c | 5 +++++ 2 files changed, 6 insertions(+) --- linux-next-20210416.orig/arch/powerpc/lib/Makefile +++ linux-next-20210416/arch/powerpc/lib/Makefile @@ -54,6 +54,7 @@ obj-y += checksum_$(BITS).o checksum_w obj-y += sstep.o obj-$(CONFIG_PPC_FPU) += ldstfp.o +obj-$(CONFIG_ALTIVEC) += ldstfp.o obj64-y += quad.o obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o --- linux-next-20210416.orig/arch/powerpc/lib/sstep.c +++ linux-next-20210416/arch/powerpc/lib/sstep.c @@ -50,6 +50,11 @@ extern void conv_sp_to_dp(const float *s extern void conv_dp_to_sp(const double *dp, float *sp); #endif +#ifdef CONFIG_ALTIVEC +extern void get_vr(int rn, __vector128 *p); +extern void put_vr(int rn, __vector128 *p); +#endif /* CONFIG_ALTIVEC */ + #ifdef __powerpc64__ /* * Functions in quad.S