Quoting Claudio Imbrenda (2023-07-13 10:20:13) [...] > > diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h > > index bb26e008cc68..53279572a9ee 100644 > > --- a/lib/s390x/asm/arch_def.h > > +++ b/lib/s390x/asm/arch_def.h > > @@ -37,12 +37,36 @@ struct stack_frame_int { > > }; > > > > struct psw { > > - uint64_t mask; > > + union { > > + uint64_t mask; > > + struct { > > + uint8_t reserved00:1; > > + uint8_t per:1; > > + uint8_t reserved02:3; > > + uint8_t dat:1; > > + uint8_t io:1; > > + uint8_t ext:1; > > + uint8_t key:4; > > + uint8_t reserved12:1; > > + uint8_t mchk:1; > > + uint8_t wait:1; > > + uint8_t pstate:1; > > + uint8_t as:2; > > + uint8_t cc:2; > > + uint8_t prg_mask:4; > > + uint8_t reserved24:7; > > + uint8_t ea:1; > > + uint8_t ba:1; > > + uint32_t reserved33:31; > > since you will need to respin this anyway: > > can you use uint64_t everywhere in the bitfield? it would look more > consistent and it would avoid some potential pitfalls of using > bitfields. In our case we're lucky because all fields are properly > aligned, but using uint64_t makes it easier to understand. I will do that for consistency, I'd be interested to understand what pitfalls you're talking about and how uint64_t avoids them, since we have a few bitfields in the codebase.