Messages in this thread | | | Date | Fri, 28 Nov 2014 11:02:20 +0100 | From | Cornelia Huck <> | Subject | Re: [PATCH v6 01/46] virtio: add low-level APIs for feature bits |
| |
On Thu, 27 Nov 2014 22:07:36 +0200 "Michael S. Tsirkin" <mst@redhat.com> wrote:
> Add low level APIs to test/set/clear feature bits. > For use by transports, to make it easier to > write code independent of feature bit array format. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > include/linux/virtio_config.h | 53 ++++++++++++++++++++++++++++++++++++++++--- > 1 file changed, 50 insertions(+), 3 deletions(-) > > diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h > index 7f4ef66..249fcd6 100644 > --- a/include/linux/virtio_config.h > +++ b/include/linux/virtio_config.h > @@ -77,11 +77,47 @@ void virtio_check_driver_offered_feature(const struct virtio_device *vdev, > unsigned int fbit); > > /** > - * virtio_has_feature - helper to determine if this device has this feature. > + * __virtio_test_bit - helper to test feature bits. For use by transports. > + * Devices should normally use virtio_has_feature, > + * which includes more checks. > * @vdev: the device > * @fbit: the feature bit > */ > -static inline bool virtio_has_feature(const struct virtio_device *vdev, > +static inline bool __virtio_test_bit(const struct virtio_device *vdev, > + unsigned int fbit) > +{ > + /* Did you forget to fix assumptions on max features? */ > + if (__builtin_constant_p(fbit)) > + BUILD_BUG_ON(fbit >= 32); > + else > + BUG_ON(fbit >= 32);
Does this want to be a helper? Might be overkill, but I'm always wary of changes that need to be applied manually in many different places :)
> + > + return test_bit(fbit, vdev->features); > +} > + > +/** > + * __virtio_set_bit - helper to set feature bits. For use by transports. > + * @vdev: the device > + * @fbit: the feature bit > + */ > +static inline void __virtio_set_bit(struct virtio_device *vdev, > + unsigned int fbit) > +{ > + /* Did you forget to fix assumptions on max features? */ > + if (__builtin_constant_p(fbit)) > + BUILD_BUG_ON(fbit >= 32); > + else > + BUG_ON(fbit >= 32); > + > + set_bit(fbit, vdev->features); > +} > + > +/** > + * __virtio_clear_bit - helper to set feature bits. For use by transports.
s/set/clear/
> + * @vdev: the device > + * @fbit: the feature bit > + */ > +static inline void __virtio_clear_bit(struct virtio_device *vdev, > unsigned int fbit) > { > /* Did you forget to fix assumptions on max features? */ > @@ -90,10 +126,21 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, > else > BUG_ON(fbit >= 32); > > + clear_bit(fbit, vdev->features); > +} > + > +/** > + * virtio_has_feature - helper to determine if this device has this feature. > + * @vdev: the device > + * @fbit: the feature bit > + */ > +static inline bool virtio_has_feature(const struct virtio_device *vdev, > + unsigned int fbit) > +{ > if (fbit < VIRTIO_TRANSPORT_F_START) > virtio_check_driver_offered_feature(vdev, fbit); > > - return test_bit(fbit, vdev->features); > + return __virtio_test_bit(vdev, fbit); > } > > static inline
| |