On a kernel config with ALTIVEC=y and PPC_FPU not set/enabled, there are build errors:
drivers/cpufreq/pmac32-cpufreq.c:262:2: error: implicit declaration of function 'enable_kernel_fp' [-Werror,-Wimplicit-function-declaration] enable_kernel_fp(); ../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); | ^~~~~~ In theory ALTIVEC is independent of PPC_FPU but in practice nobody is going to build such a machine, so make ALTIVEC require PPC_FPU by selecting it. Signed-off-by: Randy Dunlap <rdun...@infradead.org> Reported-by: kernel test robot <l...@intel.com> 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 --- v2: change ALTIVEC depends on PPC_FPU to select (Christophe and Michael) arch/powerpc/platforms/86xx/Kconfig | 1 + arch/powerpc/platforms/Kconfig.cputype | 2 ++ 2 files changed, 3 insertions(+) --- linux-next-20210416.orig/arch/powerpc/platforms/86xx/Kconfig +++ linux-next-20210416/arch/powerpc/platforms/86xx/Kconfig @@ -4,6 +4,7 @@ menuconfig PPC_86xx bool "86xx-based boards" depends on PPC_BOOK3S_32 select FSL_SOC + select PPC_FPU select ALTIVEC help The Freescale E600 SoCs have 74xx cores. --- linux-next-20210416.orig/arch/powerpc/platforms/Kconfig.cputype +++ linux-next-20210416/arch/powerpc/platforms/Kconfig.cputype @@ -186,6 +186,7 @@ config E300C3_CPU config G4_CPU bool "G4 (74xx)" depends on PPC_BOOK3S_32 + select PPC_FPU select ALTIVEC endchoice @@ -310,6 +311,7 @@ config PHYS_64BIT config ALTIVEC bool "AltiVec Support" depends on PPC_BOOK3S_32 || PPC_BOOK3S_64 || (PPC_E500MC && PPC64) + select PPC_FPU help This option enables kernel support for the Altivec extensions to the PowerPC processor. The kernel currently supports saving and restoring