C++ (Cpp) vtblk_alloc_requests Examples

Example #1

File: virtio_blk.c Project: rchander/freebsd

static int
vtblk_attach(device_t dev)
{
	struct vtblk_softc *sc;
	struct virtio_blk_config blkcfg;
	int error;

	sc = device_get_softc(dev);
	sc->vtblk_dev = dev;

	VTBLK_LOCK_INIT(sc, device_get_nameunit(dev));

	bioq_init(&sc->vtblk_bioq);
	TAILQ_INIT(&sc->vtblk_req_free);
	TAILQ_INIT(&sc->vtblk_req_ready);

	virtio_set_feature_desc(dev, vtblk_feature_desc);
	vtblk_negotiate_features(sc);

	if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
		sc->vtblk_flags |= VTBLK_FLAG_INDIRECT;
	if (virtio_with_feature(dev, VIRTIO_BLK_F_RO))
		sc->vtblk_flags |= VTBLK_FLAG_READONLY;
	if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
		sc->vtblk_flags |= VTBLK_FLAG_BARRIER;

	/* Get local copy of config. */
	virtio_read_device_config(dev, 0, &blkcfg,
	    sizeof(struct virtio_blk_config));

	/*
	 * With the current sglist(9) implementation, it is not easy
	 * for us to support a maximum segment size as adjacent
	 * segments are coalesced. For now, just make sure it's larger
	 * than the maximum supported transfer size.
	 */
	if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) {
		if (blkcfg.size_max < MAXPHYS) {
			error = ENOTSUP;
			device_printf(dev, "host requires unsupported "
			    "maximum segment size feature\n");
			goto fail;
		}
	}

	sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg);
	if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) {
		error = EINVAL;
		device_printf(dev, "fewer than minimum number of segments "
		    "allowed: %d\n", sc->vtblk_max_nsegs);
		goto fail;
	}

	sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT);
	if (sc->vtblk_sglist == NULL) {
		error = ENOMEM;
		device_printf(dev, "cannot allocate sglist\n");
		goto fail;
	}

	error = vtblk_alloc_virtqueue(sc);
	if (error) {
		device_printf(dev, "cannot allocate virtqueue\n");
		goto fail;
	}

	error = vtblk_alloc_requests(sc);
	if (error) {
		device_printf(dev, "cannot preallocate requests\n");
		goto fail;
	}

	vtblk_alloc_disk(sc, &blkcfg);

	TASK_INIT(&sc->vtblk_intr_task, 0, vtblk_intr_task, sc);
	sc->vtblk_tq = taskqueue_create_fast("vtblk_taskq", M_NOWAIT,
	    taskqueue_thread_enqueue, &sc->vtblk_tq);
	if (sc->vtblk_tq == NULL) {
		error = ENOMEM;
		device_printf(dev, "cannot allocate taskqueue\n");
		goto fail;
	}

	error = virtio_setup_intr(dev, INTR_TYPE_BIO | INTR_ENTROPY);
	if (error) {
		device_printf(dev, "cannot setup virtqueue interrupt\n");
		goto fail;
	}

	taskqueue_start_threads(&sc->vtblk_tq, 1, PI_DISK, "%s taskq",
	    device_get_nameunit(dev));

	vtblk_create_disk(sc);

	virtqueue_enable_intr(sc->vtblk_vq);

fail:
	if (error)
		vtblk_detach(dev);

	return (error);
}

Example #2

File: virtio_blk.c Project: wan721/DragonFlyBSD

static int
vtblk_attach(device_t dev)
{
	struct vtblk_softc *sc;
	struct virtio_blk_config blkcfg;
	int error;

	sc = device_get_softc(dev);
	sc->vtblk_dev = dev;

	lwkt_serialize_init(&sc->vtblk_slz);

	bioq_init(&sc->vtblk_bioq);
	TAILQ_INIT(&sc->vtblk_req_free);
	TAILQ_INIT(&sc->vtblk_req_ready);

	virtio_set_feature_desc(dev, vtblk_feature_desc);
	vtblk_negotiate_features(sc);

	if (virtio_with_feature(dev, VIRTIO_BLK_F_RO))
		sc->vtblk_flags |= VTBLK_FLAG_READONLY;
	if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
		sc->vtblk_flags |= VTBLK_FLAG_BARRIER;
	if (virtio_with_feature(dev, VIRTIO_BLK_F_CONFIG_WCE))
		sc->vtblk_flags |= VTBLK_FLAG_WC_CONFIG;

	vtblk_setup_sysctl(sc);

	/* Get local copy of config. */
	virtio_read_device_config(dev, 0, &blkcfg,
				  sizeof(struct virtio_blk_config));

	/*
	 * With the current sglist(9) implementation, it is not easy
	 * for us to support a maximum segment size as adjacent
	 * segments are coalesced. For now, just make sure it's larger
	 * than the maximum supported transfer size.
	 */
	if (virtio_with_feature(dev, VIRTIO_BLK_F_SIZE_MAX)) {
		if (blkcfg.size_max < MAXPHYS) {
			error = ENOTSUP;
			device_printf(dev, "host requires unsupported "
			    "maximum segment size feature\n");
			goto fail;
		}
	}

	sc->vtblk_max_nsegs = vtblk_maximum_segments(sc, &blkcfg);
	if (sc->vtblk_max_nsegs <= VTBLK_MIN_SEGMENTS) {
		error = EINVAL;
		device_printf(dev, "fewer than minimum number of segments "
		    "allowed: %d\n", sc->vtblk_max_nsegs);
		goto fail;
	}

	/*
	 * Allocate working sglist. The number of segments may be too
	 * large to safely store on the stack.
	 */
	sc->vtblk_sglist = sglist_alloc(sc->vtblk_max_nsegs, M_NOWAIT);
	if (sc->vtblk_sglist == NULL) {
		error = ENOMEM;
		device_printf(dev, "cannot allocate sglist\n");
		goto fail;
	}

	error = vtblk_alloc_virtqueue(sc);
	if (error) {
		device_printf(dev, "cannot allocate virtqueue\n");
		goto fail;
	}

	error = vtblk_alloc_requests(sc);
	if (error) {
		device_printf(dev, "cannot preallocate requests\n");
		goto fail;
	}

	vtblk_alloc_disk(sc, &blkcfg);

	error = virtio_setup_intr(dev, &sc->vtblk_slz);
	if (error) {
		device_printf(dev, "cannot setup virtqueue interrupt\n");
		goto fail;
	}

	virtqueue_enable_intr(sc->vtblk_vq);

fail:
	if (error)
		vtblk_detach(dev);

	return (error);
}