[resend PATCH v2 29/33] uio, libnvdimm, pmem: implement cache bypass for all copy_from_iter() operations

Introduce copy_from_iter_ops() to enable passing custom sub-routines to iterate_and_advance(). Define pmem operations that guarantee cache bypass to supplement the existing usage of __copy_from_iter_nocache() backed by arch_wb_cache_pmem(). Cc: Jan Kara Cc: Jeff Moyer

[resend PATCH v2 29/33] uio, libnvdimm, pmem: implement cache bypass for all copy_from_iter() operations

Introduce copy_from_iter_ops() to enable passing custom sub-routines to iterate_and_advance(). Define pmem operations that guarantee cache bypass to supplement the existing usage of __copy_from_iter_nocache() backed by arch_wb_cache_pmem(). Cc: Jan Kara Cc: Jeff Moyer Cc: Christoph Hellwig Cc: