On Tue, Aug 04, 2020 at 04:23:40PM +0200, Cornelia Huck wrote: > On Mon, 3 Aug 2020 16:58:46 -0400 > "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > > Currently all config space fields are of the type __uXX. > > This confuses people and some drivers (notably vdpa) > > access them using CPU endian-ness - which only > > works well for legacy or LE platforms. > > > > Update virtio_cread/virtio_cwrite macros to allow __virtioXX > > and __leXX field types. Follow-up patches will convert > > config space to use these types. > > > > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > > --- > > include/linux/virtio_config.h | 50 +++++++++++++++++++++++++++++++++-- > > 1 file changed, 48 insertions(+), 2 deletions(-) > > (...) > > > @@ -287,12 +288,57 @@ static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val) > > return __cpu_to_virtio64(virtio_is_little_endian(vdev), val); > > } > > > > +/* > > + * Only the checker differentiates between __virtioXX and __uXX types. But we > > + * try to share as much code as we can with the regular GCC build. > > + */ > > +#if !defined(CONFIG_CC_IS_GCC) && !defined(__CHECKER__) > > + > > +/* Not a checker - we can keep things simple */ > > +#define __virtio_native_typeof(x) typeof(x) > > + > > +#else > > + > > +/* > > + * We build this out of a couple of helper macros in a vain attempt to > > + * help you keep your lunch down while reading it. > > + */ > > It might help with the lunch, but it still gives a slight queasiness. > No ideas for a better version, though. A later patch fixes this. Hopefully :) > > +#define __virtio_pick_value(x, type, then, otherwise) \ > > + __builtin_choose_expr(__same_type(x, type), then, otherwise) > > + > > +#define __virtio_pick_type(x, type, then, otherwise) \ > > + __virtio_pick_value(x, type, (then)0, otherwise) > > + > > +#define __virtio_pick_endian(x, x16, x32, x64, otherwise) \ > > + __virtio_pick_type(x, x16, __u16, \ > > + __virtio_pick_type(x, x32, __u32, \ > > + __virtio_pick_type(x, x64, __u64, \ > > + otherwise))) > > + > > +#define __virtio_native_typeof(x) typeof( \ > > + __virtio_pick_type(x, __u8, __u8, \ > > + __virtio_pick_endian(x, __virtio16, __virtio32, __virtio64, \ > > + __virtio_pick_endian(x, __le16, __le32, __le64, \ > > + __virtio_pick_endian(x, __u16, __u32, __u64, \ > > + /* No other type allowed */ \ > > + (void)0))))) > > + > > +#endif > > + > > +#define __virtio_native_type(structname, member) \ > > + __virtio_native_typeof(((structname*)0)->member) > > + > > +#define __virtio_typecheck(structname, member, val) \ > > + /* Must match the member's type, and be integer */ \ > > + typecheck(__virtio_native_type(structname, member), (val)) > > + > > + > > Acked-by: Cornelia Huck <cohuck@xxxxxxxxxx> _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
