It previously returned the cookie directly, which made it impossible
to distinguish between a NULL cookie and the function not having
anything to dequeue. This lead to some code setting a cookie that was
not actually used.
Return the dequeue status as a boolean and provide the cookie with an
optionally handed in pointer instead and adjust all users.
Change-Id: Iaac1726ac4bc7ae42bb96b8f0915852b6def5822
Reviewed-on: https://review.haiku-os.org/c/haiku/+/1814
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
The size was in fact the count of physical entries that were used. That
number must necessarily be the same as the number given when adding to
the queue, so that number isn't really interesting. Consequently none
of the users of that API made use of it.
Return the used length instead, which is the way virtio signals how much
valid data resides in the dequeued buffer. This is for example important
to know the frame length of incoming packets in virtio_net.
* free interrupts, free queues, return to init state.
* this will be used by virtio_net on interface uninit.
Change-Id: I7c1e6facc37cf6bfe19628576fdf2c0bac9e5c38
* enable to iterate on available entries in one interrupt call.
* negociate -> negotiate, (void *) -> (void* ), thanks axel and philippe!
Change-Id: Ie2d290797abcbf4c0f3cb5bfff71d091bb800fa6
* the processing of requests in drivers is eased a bit with this change, but
this could be improved for instance by enabling a driver to dequeue items
in a service thread instead of the interrupt handler.
* made a few methods const.
* make use of MSI/MSI-X PCI x86 API
* MSI support untested because QEmu only offers MSI-X
* changed a bit the Virtio bus API by adding a queue count parameter
for the setup_interrupt() hook.
* the Virtio PCI bus driver exposes a Virtio controller to the Virtio bus manager,
which in turn exposes a Virtio device consumed by Virtio drivers. Drivers follow the
new driver model.
* virtio_block handles Virtio block devices under disk/virtual/virtio_block/x/raw.
* Here is the Qemu command line option for Virtio disk devices:
-drive file=haiku.image,if=virtio
* the PCI bus driver currently supports only legacy interrupts (no MSI(-X) yet).
* There is room for improvements in the bus manager:
- it notifies the host for each queued request, which isn't optimal.
- transfer descriptors should probably be simply preallocated (they are nicely
leaked at the moment).
- indirect descriptors are not supported yet.
and in the block driver:
- get the id of the disk.
- implements flushing the cache.
- improves dma restrictions.
- do_io() should use a page for header descriptors instead of malloc(), which
could cross boundaries.
* The device manager tries to guess the driver based on the PCI device type, this
implies having to declare the "busses/virtio" path for each possible type
provided by Virtio. Thus future driver additions might require patching the device
manager.
* virtio.h is still private, the API is subject to changes.
* virtio_pci.h, virtio_blk.h, virtio_ring.h are copied unchanged from FreeBSD.
