linux/drivers/virtio
Rusty Russell ee7cd8981e virtio: expose added descriptors immediately.
A virtio driver does virtqueue_add_buf() multiple times before finally
calling virtqueue_kick(); previously we only exposed the added buffers
in the virtqueue_kick() call.  This means we don't need a memory
barrier in virtqueue_add_buf(), but it reduces concurrency as the
device (ie. host) can't see the buffers until the kick.

In the unusual (but now possible) case where a driver does add_buf()
and get_buf() without doing a kick, we do need to insert one before
our counter wraps.  Otherwise we could wrap num_added, and later on
not realize that we have passed the marker where we should have
kicked.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:43 +10:30
..
config.c
Kconfig virtio: add HAS_IOMEM dependency to MMIO platform bus driver 2011-11-24 13:04:47 +10:30
Makefile virtio: Add platform bus driver for memory mapped virtio device 2011-11-02 11:41:01 +10:30
virtio_balloon.c virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf 2012-01-12 15:44:42 +10:30
virtio_mmio.c virtio: harsher barriers for rpmsg. 2012-01-12 15:44:42 +10:30
virtio_pci.c virtio: harsher barriers for rpmsg. 2012-01-12 15:44:42 +10:30
virtio_ring.c virtio: expose added descriptors immediately. 2012-01-12 15:44:43 +10:30
virtio.c virtio: Add module.h to drivers/virtio users. 2011-10-31 19:32:14 -04:00