> +void clean_cache_range(void *addr, size_t size); > > static inline int > __copy_from_user_inatomic_nocache(void *dst, const void __user *src, > diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c > index f42d2fd86ca3..baa80ff29da8 100644 > --- a/arch/x86/lib/usercopy_64.c > +++ b/arch/x86/lib/usercopy_64.c > @@ -85,7 +85,7 @@ copy_user_handle_tail(char *to, char *from, unsigned len) > * instruction. Note that @size is internally rounded up to be cache > * line size aligned. > */ > -static void clean_cache_range(void *addr, size_t size) > +void clean_cache_range(void *addr, size_t size) Can you keep clean_cache_range private please? Just add arch_wb_cache_pmem to usercopy_64.c just behind it so that the compiler can tail-call and export that instead. > --- a/drivers/nvdimm/pmem.h > +++ b/drivers/nvdimm/pmem.h > @@ -4,6 +4,13 @@ > #include <linux/types.h> > #include <linux/pfn_t.h> > #include <linux/fs.h> > +#include <asm/pmem.h> > + > +#ifndef CONFIG_ARCH_HAS_PMEM_API > +static inline void arch_wb_cache_pmem(void *addr, size_t size) > +{ > +} > +#endif And our normal Linux style would be to have this linux linux/pmem.h, which should always be included for the asm version.