On Fri, Feb 25, 2022 at 06:42:37PM +0000, Tvrtko Ursulin wrote: > Matthew, what do you think fix for this build warning on h8300 and s390 should be? Or perhaps a build environment issue with kernel test robot? I'd suggest this should do the job: +++ b/include/linux/cacheflush.h @@ -4,6 +4,8 @@ #include <asm/cacheflush.h> +struct folio; + #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO void flush_dcache_folio(struct folio *folio);