Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit dd7c7bc4 authored by Rusty Russell's avatar Rusty Russell
Browse files

virtio: Formally reserve bits 28-31 to be 'transport' features. 



We assign feature bits as required, but it makes sense to reserve some
for the particular transport, rather than the particular device.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent faeba830

drivers/virtio/virtio.c

+5 −0
Original line number Diff line number Diff line
@@ -113,6 +113,11 @@ static int virtio_dev_probe(struct device *_d) 
			set_bit(f, dev->features);

	}



	/* Transport features are always preserved to pass to set_features. */

	for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)

		if (device_features & (1 << i))

			set_bit(i, dev->features);



	err = drv->probe(dev);

	if (err)

		add_status(dev, VIRTIO_CONFIG_S_FAILED);

include/linux/virtio_config.h

+6 −0
Original line number Diff line number Diff line
@@ -18,6 +18,12 @@ 
/* We've given up on this device. */

#define VIRTIO_CONFIG_S_FAILED		0x80



/* Some virtio feature bits (currently bits 28 through 31) are reserved for the

 * transport being used (eg. virtio_ring), the rest are per-device feature

 * bits. */

#define VIRTIO_TRANSPORT_F_START	28

#define VIRTIO_TRANSPORT_F_END		32



/* Do we get callbacks when the ring is completely used, even if we've

 * suppressed them? */

#define VIRTIO_F_NOTIFY_ON_EMPTY	24