On Mon, Nov 24, 2014 at 12:52 PM, Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> virtio 1.0 makes all memory structures LE, so
> we need APIs to conditionally do a byteswap on BE
> architectures.
>
> To make it easier to check code statically,
> add virtio specific types for multi-byte integers
> in memory.
>
> Add low level wrappers that do a byteswap conditionally, these will be
> useful e.g. for vhost. Add high level wrappers that
> query device endian-ness and act accordingly.
> diff --git a/include/linux/virtio_byteorder.h b/include/linux/virtio_byteorder.h
> new file mode 100644
> index 0000000..824ed0b
> --- /dev/null
> +++ b/include/linux/virtio_byteorder.h
> +static inline u16 __virtio16_to_cpu(bool little_endian, __virtio16 val)
> +{
> + if (little_endian)
> + return le16_to_cpu((__force __le16)val);
> + else
> + return (__force u16)val;
> +}
What's wrong with just using le16-to_cpu() ...
> --- a/include/uapi/linux/virtio_ring.h
> +++ b/include/uapi/linux/virtio_ring.h
> /* Virtio ring descriptors: 16 bytes. These can chain together via "next". */
> struct vring_desc {
> /* Address (guest-physical). */
> - __u64 addr;
> + __virtio64 addr;
... and __le64?
There's already lots of precedence or this, even in include/uapi/.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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